| Message ID | 20220125202118.63362-1-andriy.shevchenko@linux.intel.com |
|---|---|
| Headers | show |
| Series | fbtft: Unorphan the driver for maintenance | expand |
Hi Am 25.01.22 um 21:21 schrieb Andy Shevchenko: > Since we got a maintainer for fbdev, I would like to > unorphan fbtft (with the idea of sending PRs to Helge) > and move it out of staging since there is no more clean > up work expected and no more drivers either. > > Thoughts? But why? We already have DRM drivers for some of these devices. Porting the others to DRM is such a better long-term plan. OTOH, as no one has shown up and converted them, maybe they should be left dead or removed entirely. Best regards Thomas > > Andy Shevchenko (4): > fbtft: Unorphan the driver > fbtft: Move driver out from staging > fbtft: Kill outdated documentation > fbtft: Replace 'depends on FB_TFT' by 'if FB_TFT ... endif' > > MAINTAINERS | 6 ++-- > drivers/staging/Kconfig | 2 -- > drivers/staging/Makefile | 1 - > drivers/staging/fbtft/README | 32 ------------------ > drivers/staging/fbtft/TODO | 3 -- > drivers/video/Kconfig | 1 + > drivers/video/Makefile | 1 + > drivers/{staging => video}/fbtft/Kconfig | 33 +++---------------- > drivers/{staging => video}/fbtft/Makefile | 0 > .../{staging => video}/fbtft/fb_agm1264k-fl.c | 0 > .../{staging => video}/fbtft/fb_bd663474.c | 0 > .../{staging => video}/fbtft/fb_hx8340bn.c | 0 > drivers/{staging => video}/fbtft/fb_hx8347d.c | 0 > drivers/{staging => video}/fbtft/fb_hx8353d.c | 0 > drivers/{staging => video}/fbtft/fb_hx8357d.c | 0 > drivers/{staging => video}/fbtft/fb_hx8357d.h | 0 > drivers/{staging => video}/fbtft/fb_ili9163.c | 0 > drivers/{staging => video}/fbtft/fb_ili9320.c | 0 > drivers/{staging => video}/fbtft/fb_ili9325.c | 0 > drivers/{staging => video}/fbtft/fb_ili9340.c | 0 > drivers/{staging => video}/fbtft/fb_ili9341.c | 0 > drivers/{staging => video}/fbtft/fb_ili9481.c | 0 > drivers/{staging => video}/fbtft/fb_ili9486.c | 0 > drivers/{staging => video}/fbtft/fb_pcd8544.c | 0 > drivers/{staging => video}/fbtft/fb_ra8875.c | 0 > drivers/{staging => video}/fbtft/fb_s6d02a1.c | 0 > drivers/{staging => video}/fbtft/fb_s6d1121.c | 0 > drivers/{staging => video}/fbtft/fb_seps525.c | 0 > drivers/{staging => video}/fbtft/fb_sh1106.c | 0 > drivers/{staging => video}/fbtft/fb_ssd1289.c | 0 > drivers/{staging => video}/fbtft/fb_ssd1305.c | 0 > drivers/{staging => video}/fbtft/fb_ssd1306.c | 0 > drivers/{staging => video}/fbtft/fb_ssd1325.c | 0 > drivers/{staging => video}/fbtft/fb_ssd1331.c | 0 > drivers/{staging => video}/fbtft/fb_ssd1351.c | 0 > drivers/{staging => video}/fbtft/fb_st7735r.c | 0 > drivers/{staging => video}/fbtft/fb_st7789v.c | 0 > drivers/{staging => video}/fbtft/fb_tinylcd.c | 0 > drivers/{staging => video}/fbtft/fb_tls8204.c | 0 > drivers/{staging => video}/fbtft/fb_uc1611.c | 0 > drivers/{staging => video}/fbtft/fb_uc1701.c | 0 > .../{staging => video}/fbtft/fb_upd161704.c | 0 > drivers/{staging => video}/fbtft/fbtft-bus.c | 0 > drivers/{staging => video}/fbtft/fbtft-core.c | 0 > drivers/{staging => video}/fbtft/fbtft-io.c | 0 > .../{staging => video}/fbtft/fbtft-sysfs.c | 0 > drivers/{staging => video}/fbtft/fbtft.h | 0 > drivers/{staging => video}/fbtft/internal.h | 0 > 48 files changed, 10 insertions(+), 69 deletions(-) > delete mode 100644 drivers/staging/fbtft/README > delete mode 100644 drivers/staging/fbtft/TODO > rename drivers/{staging => video}/fbtft/Kconfig (89%) > rename drivers/{staging => video}/fbtft/Makefile (100%) > rename drivers/{staging => video}/fbtft/fb_agm1264k-fl.c (100%) > rename drivers/{staging => video}/fbtft/fb_bd663474.c (100%) > rename drivers/{staging => video}/fbtft/fb_hx8340bn.c (100%) > rename drivers/{staging => video}/fbtft/fb_hx8347d.c (100%) > rename drivers/{staging => video}/fbtft/fb_hx8353d.c (100%) > rename drivers/{staging => video}/fbtft/fb_hx8357d.c (100%) > rename drivers/{staging => video}/fbtft/fb_hx8357d.h (100%) > rename drivers/{staging => video}/fbtft/fb_ili9163.c (100%) > rename drivers/{staging => video}/fbtft/fb_ili9320.c (100%) > rename drivers/{staging => video}/fbtft/fb_ili9325.c (100%) > rename drivers/{staging => video}/fbtft/fb_ili9340.c (100%) > rename drivers/{staging => video}/fbtft/fb_ili9341.c (100%) > rename drivers/{staging => video}/fbtft/fb_ili9481.c (100%) > rename drivers/{staging => video}/fbtft/fb_ili9486.c (100%) > rename drivers/{staging => video}/fbtft/fb_pcd8544.c (100%) > rename drivers/{staging => video}/fbtft/fb_ra8875.c (100%) > rename drivers/{staging => video}/fbtft/fb_s6d02a1.c (100%) > rename drivers/{staging => video}/fbtft/fb_s6d1121.c (100%) > rename drivers/{staging => video}/fbtft/fb_seps525.c (100%) > rename drivers/{staging => video}/fbtft/fb_sh1106.c (100%) > rename drivers/{staging => video}/fbtft/fb_ssd1289.c (100%) > rename drivers/{staging => video}/fbtft/fb_ssd1305.c (100%) > rename drivers/{staging => video}/fbtft/fb_ssd1306.c (100%) > rename drivers/{staging => video}/fbtft/fb_ssd1325.c (100%) > rename drivers/{staging => video}/fbtft/fb_ssd1331.c (100%) > rename drivers/{staging => video}/fbtft/fb_ssd1351.c (100%) > rename drivers/{staging => video}/fbtft/fb_st7735r.c (100%) > rename drivers/{staging => video}/fbtft/fb_st7789v.c (100%) > rename drivers/{staging => video}/fbtft/fb_tinylcd.c (100%) > rename drivers/{staging => video}/fbtft/fb_tls8204.c (100%) > rename drivers/{staging => video}/fbtft/fb_uc1611.c (100%) > rename drivers/{staging => video}/fbtft/fb_uc1701.c (100%) > rename drivers/{staging => video}/fbtft/fb_upd161704.c (100%) > rename drivers/{staging => video}/fbtft/fbtft-bus.c (100%) > rename drivers/{staging => video}/fbtft/fbtft-core.c (100%) > rename drivers/{staging => video}/fbtft/fbtft-io.c (100%) > rename drivers/{staging => video}/fbtft/fbtft-sysfs.c (100%) > rename drivers/{staging => video}/fbtft/fbtft.h (100%) > rename drivers/{staging => video}/fbtft/internal.h (100%) >
On Wed, Jan 26, 2022 at 12:02 PM Andy Shevchenko <andy.shevchenko@gmail.com> wrote: > On Wed, Jan 26, 2022 at 10:52 AM Thomas Zimmermann <tzimmermann@suse.de> wrote: > > Am 25.01.22 um 21:21 schrieb Andy Shevchenko: ... > > But why? We already have DRM drivers for some of these devices. > > No, we do not (only a few are available). Sorry, I missed your word 'some'. Some == almost none from the list (I don't remember exact numbers but something like 2 out of 10 are supported by tiny DRM and see about interfaces).
On Wed, Jan 26, 2022 at 9:31 AM Greg Kroah-Hartman <gregkh@linuxfoundation.org> wrote: > > On Tue, Jan 25, 2022 at 10:21:14PM +0200, Andy Shevchenko wrote: > > Let's maintain occasional fixes to the fbtft driver. > > > > Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> > > --- > > MAINTAINERS | 4 +++- > > 1 file changed, 3 insertions(+), 1 deletion(-) > > > > diff --git a/MAINTAINERS b/MAINTAINERS > > index ea3e6c914384..16e614606ac1 100644 > > --- a/MAINTAINERS > > +++ b/MAINTAINERS > > @@ -7372,9 +7372,11 @@ F: Documentation/fault-injection/ > > F: lib/fault-inject.c > > > > FBTFT Framebuffer drivers > > +M: Andy Shevchenko <andy@kernel.org> > > L: dri-devel@lists.freedesktop.org > > L: linux-fbdev@vger.kernel.org > > -S: Orphan > > +S: Maintained > > +T: git git://git.kernel.org/pub/scm/linux/kernel/git/andy/linux-fbtft.git > > I'm ok with the files moving if the dri developers agree with it. It's > up to them, not me. On one hand I'm happy anytime someone volunteers to help out. On the other hand ... why does it have to be resurrecting fbdev? There's an entire community of people who really know graphics and display and spent considerable amount of effort on creating useful and documented helpers for pretty much anything you might ever want to do. And somehow we have to go back to typing out things the hard way, with full verbosity, for an uapi that distros are abandoning (e.g. even for sdl the direction is to run it on top of drm with a compat layer, afaiui fedora is completely ditching any userspace that still even uses /dev/fb/0). And yes I know there's still some gaps in drm, largely for display features which were really en vogue about 20 years ago. And we're happy to add that support, if someone who still has such hardware can put in the little bit of work needed ... I don't get this. -Daniel -- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch
On Wed, Jan 26, 2022 at 12:02:36PM +0200, Andy Shevchenko wrote: > On Wed, Jan 26, 2022 at 10:52 AM Thomas Zimmermann <tzimmermann@suse.de> wrote: > > > > Hi > > > > Am 25.01.22 um 21:21 schrieb Andy Shevchenko: > > > Since we got a maintainer for fbdev, I would like to > > > unorphan fbtft (with the idea of sending PRs to Helge) > > > and move it out of staging since there is no more clean > > > up work expected and no more drivers either. > > > > > > Thoughts? > > Thanks for sharing yours, my answers below. > > > But why? We already have DRM drivers for some of these devices. > > No, we do not (only a few are available). > > > Porting > > the others to DRM is such a better long-term plan. OTOH, as no one has > > shown up and converted them, maybe they should be left dead or removed > > entirely. > > As I mentioned above there are devices that nobody will take time to > port to a way too complex DRM subsystem. But the devices are cheap and > quite widespread in the embedded world. I'm in possession of 3 or 4 > different models and only 1 is supported by tiny DRM. Great, then let's just move the 2 models that you do not have support for in DRM, not the whole lot. When we have real users for the drivers, we can move them out of staging, but until then, dragging all of them out does not make sense. thanks, greg k-h
On 1/26/22 11:02, Andy Shevchenko wrote: > On Wed, Jan 26, 2022 at 10:52 AM Thomas Zimmermann <tzimmermann@suse.de> wrote: >> Am 25.01.22 um 21:21 schrieb Andy Shevchenko: >>> Since we got a maintainer for fbdev, I would like to >>> unorphan fbtft (with the idea of sending PRs to Helge) >>> and move it out of staging since there is no more clean >>> up work expected and no more drivers either. >>> >>> Thoughts? Personally I'm in favour of this proposal and would be happy to take patches for it through the fbdev git tree. Reasoning below... >> But why? We already have DRM drivers for some of these devices. > > No, we do not (only a few are available). seems to be 2 out of 10 (according to the other mails) >> Porting the others to DRM is such a better long-term plan. OTOH, >> as no one has shown up and converted them, maybe they should be >> left dead or removed entirely. > > As I mentioned above there are devices that nobody will take time to > port to a way too complex DRM subsystem. But the devices are cheap and > quite widespread in the embedded world. I'm in possession of 3 or 4 > different models and only 1 is supported by tiny DRM. > > On top of that the subtle fact people forgot about FBTFT is that it > does support parallel interface (yes, I know that it's not performant, > but one of the displays I have is with that type of interface). I don't know those devices, but it seems they are still being used. And the reasons why they have not been ported to DRM yet is likely because either lack of man-power, a slow-down with DRM (due to slow bus connections or increased memory usage with DRM), or simply that it's used in embedded-like scenarios with a limited set of userspace applications for which existing fbdev access is sufficient. Again, I don't know the reason for this specific devices, but I know of other devices for which those reasons above are valid. Just the example I posted yesterday where a simple "time dmesg" needed unaccelerated 19 seconds compared to 2 seconds with acceleration. So, as long as acceleration isn't possible with that driver in DRM, DRM isn't a preferred target where the driver should be ported. So, I'd be fine to take it into fbdev tree. Interestingly there is another fbdev driver in staging (sm750fb) with similiar issues. The TODO mentions a porting to DRM which happens at https://gitlab.com/sudipm/sm750/tree/sm750 but the last commit there is 3 years ago. I don't know why it wasn't continued yet. > P.S. For the record, I will personally NAK any attempts to remove that > driver from the kernel. And this is another point why it's better not > to be under the staging. I agree. Same as for me to NAK the disabling of fbcon's acceleration features or even attempting to remove fbdev altogether (unless all relevant drivers are ported to DRM). Helge
On Wed, Jan 26, 2022 at 11:52:16AM +0100, Daniel Vetter wrote: > On Wed, Jan 26, 2022 at 11:47 AM Greg Kroah-Hartman > <gregkh@linuxfoundation.org> wrote: > > > > On Wed, Jan 26, 2022 at 12:02:36PM +0200, Andy Shevchenko wrote: > > > On Wed, Jan 26, 2022 at 10:52 AM Thomas Zimmermann <tzimmermann@suse.de> wrote: > > > > > > > > Hi > > > > > > > > Am 25.01.22 um 21:21 schrieb Andy Shevchenko: > > > > > Since we got a maintainer for fbdev, I would like to > > > > > unorphan fbtft (with the idea of sending PRs to Helge) > > > > > and move it out of staging since there is no more clean > > > > > up work expected and no more drivers either. > > > > > > > > > > Thoughts? > > > > > > Thanks for sharing yours, my answers below. > > > > > > > But why? We already have DRM drivers for some of these devices. > > > > > > No, we do not (only a few are available). > > > > > > > Porting > > > > the others to DRM is such a better long-term plan. OTOH, as no one has > > > > shown up and converted them, maybe they should be left dead or removed > > > > entirely. > > > > > > As I mentioned above there are devices that nobody will take time to > > > port to a way too complex DRM subsystem. But the devices are cheap and > > > quite widespread in the embedded world. I'm in possession of 3 or 4 > > > different models and only 1 is supported by tiny DRM. > > > > Great, then let's just move the 2 models that you do not have support > > for in DRM, not the whole lot. When we have real users for the drivers, > > we can move them out of staging, but until then, dragging all of them > > out does not make sense. > > Can't we create drm drivers for these 2-3 models? Like we have drivers > which are below 300 lines with all the helpers taking care of > everything, this shouldn't be too tricky. Agreed, having the hardware to test this with is the hardest part. Andy, this should be better to do in the longrun than trying to keep these other drivers "alive". thanks, greg k-h
On 1/26/22 11:31, Daniel Vetter wrote: > On Wed, Jan 26, 2022 at 9:31 AM Greg Kroah-Hartman > <gregkh@linuxfoundation.org> wrote: >> >> On Tue, Jan 25, 2022 at 10:21:14PM +0200, Andy Shevchenko wrote: >>> Let's maintain occasional fixes to the fbtft driver. >>> >>> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> >>> --- >>> MAINTAINERS | 4 +++- >>> 1 file changed, 3 insertions(+), 1 deletion(-) >>> >>> diff --git a/MAINTAINERS b/MAINTAINERS >>> index ea3e6c914384..16e614606ac1 100644 >>> --- a/MAINTAINERS >>> +++ b/MAINTAINERS >>> @@ -7372,9 +7372,11 @@ F: Documentation/fault-injection/ >>> F: lib/fault-inject.c >>> >>> FBTFT Framebuffer drivers >>> +M: Andy Shevchenko <andy@kernel.org> >>> L: dri-devel@lists.freedesktop.org >>> L: linux-fbdev@vger.kernel.org >>> -S: Orphan >>> +S: Maintained >>> +T: git git://git.kernel.org/pub/scm/linux/kernel/git/andy/linux-fbtft.git >> >> I'm ok with the files moving if the dri developers agree with it. It's >> up to them, not me. > > On one hand I'm happy anytime someone volunteers to help out. > > On the other hand ... why does it have to be resurrecting fbdev? > There's an entire community of people who really know graphics and > display and spent considerable amount of effort on creating useful and > documented helpers for pretty much anything you might ever want to do. > And somehow we have to go back to typing out things the hard way, with > full verbosity, for an uapi that distros are abandoning (e.g. even for > sdl the direction is to run it on top of drm with a compat layer, > afaiui fedora is completely ditching any userspace that still even > uses /dev/fb/0). And yes I know there's still some gaps in drm, > largely for display features which were really en vogue about 20 years > ago. And we're happy to add that support, if someone who still has > such hardware can put in the little bit of work needed ... > > I don't get this. You are describing a transitioning over to DRM - which is Ok. But on that way there is no need to ignore, deny or even kill usage scenarios which are different compared to your usage scenarios (e.g. embedded devices, old platforms, slow devices, slow busses, no 3D hardware features, low-color devices, ...). Helge
On Wed, Jan 26, 2022 at 12:17:08PM +0100, Helge Deller wrote: > On 1/26/22 11:31, Daniel Vetter wrote: > > On Wed, Jan 26, 2022 at 9:31 AM Greg Kroah-Hartman > > <gregkh@linuxfoundation.org> wrote: > >> > >> On Tue, Jan 25, 2022 at 10:21:14PM +0200, Andy Shevchenko wrote: > >>> Let's maintain occasional fixes to the fbtft driver. > >>> > >>> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> > >>> --- > >>> MAINTAINERS | 4 +++- > >>> 1 file changed, 3 insertions(+), 1 deletion(-) > >>> > >>> diff --git a/MAINTAINERS b/MAINTAINERS > >>> index ea3e6c914384..16e614606ac1 100644 > >>> --- a/MAINTAINERS > >>> +++ b/MAINTAINERS > >>> @@ -7372,9 +7372,11 @@ F: Documentation/fault-injection/ > >>> F: lib/fault-inject.c > >>> > >>> FBTFT Framebuffer drivers > >>> +M: Andy Shevchenko <andy@kernel.org> > >>> L: dri-devel@lists.freedesktop.org > >>> L: linux-fbdev@vger.kernel.org > >>> -S: Orphan > >>> +S: Maintained > >>> +T: git git://git.kernel.org/pub/scm/linux/kernel/git/andy/linux-fbtft.git > >> > >> I'm ok with the files moving if the dri developers agree with it. It's > >> up to them, not me. > > > > On one hand I'm happy anytime someone volunteers to help out. > > > > On the other hand ... why does it have to be resurrecting fbdev? > > There's an entire community of people who really know graphics and > > display and spent considerable amount of effort on creating useful and > > documented helpers for pretty much anything you might ever want to do. > > And somehow we have to go back to typing out things the hard way, with > > full verbosity, for an uapi that distros are abandoning (e.g. even for > > sdl the direction is to run it on top of drm with a compat layer, > > afaiui fedora is completely ditching any userspace that still even > > uses /dev/fb/0). And yes I know there's still some gaps in drm, > > largely for display features which were really en vogue about 20 years > > ago. And we're happy to add that support, if someone who still has > > such hardware can put in the little bit of work needed ... > > > > I don't get this. > > You are describing a transitioning over to DRM - which is Ok. > But on that way there is no need to ignore, deny or even kill usage scenarios > which are different compared to your usage scenarios (e.g. embedded devices, > old platforms, slow devices, slow busses, no 3D hardware features, > low-color devices, ...). All of those should be handled by the drm layer, as Daniel keeps pointing out. If not, then the tinydrm layer needs to be enhanced to do so. Anyone have a pointer to hardware I can buy that is one of these fbtft drivers that I could do a port to drm to see just how much work is really needed here? thanks, greg k-h
Hi Am 26.01.22 um 12:17 schrieb Helge Deller: > On 1/26/22 11:31, Daniel Vetter wrote: >> On Wed, Jan 26, 2022 at 9:31 AM Greg Kroah-Hartman >> <gregkh@linuxfoundation.org> wrote: >>> >>> On Tue, Jan 25, 2022 at 10:21:14PM +0200, Andy Shevchenko wrote: >>>> Let's maintain occasional fixes to the fbtft driver. >>>> >>>> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> >>>> --- >>>> MAINTAINERS | 4 +++- >>>> 1 file changed, 3 insertions(+), 1 deletion(-) >>>> >>>> diff --git a/MAINTAINERS b/MAINTAINERS >>>> index ea3e6c914384..16e614606ac1 100644 >>>> --- a/MAINTAINERS >>>> +++ b/MAINTAINERS >>>> @@ -7372,9 +7372,11 @@ F: Documentation/fault-injection/ >>>> F: lib/fault-inject.c >>>> >>>> FBTFT Framebuffer drivers >>>> +M: Andy Shevchenko <andy@kernel.org> >>>> L: dri-devel@lists.freedesktop.org >>>> L: linux-fbdev@vger.kernel.org >>>> -S: Orphan >>>> +S: Maintained >>>> +T: git git://git.kernel.org/pub/scm/linux/kernel/git/andy/linux-fbtft.git >>> >>> I'm ok with the files moving if the dri developers agree with it. It's >>> up to them, not me. >> >> On one hand I'm happy anytime someone volunteers to help out. >> >> On the other hand ... why does it have to be resurrecting fbdev? >> There's an entire community of people who really know graphics and >> display and spent considerable amount of effort on creating useful and >> documented helpers for pretty much anything you might ever want to do. >> And somehow we have to go back to typing out things the hard way, with >> full verbosity, for an uapi that distros are abandoning (e.g. even for >> sdl the direction is to run it on top of drm with a compat layer, >> afaiui fedora is completely ditching any userspace that still even >> uses /dev/fb/0). And yes I know there's still some gaps in drm, >> largely for display features which were really en vogue about 20 years >> ago. And we're happy to add that support, if someone who still has >> such hardware can put in the little bit of work needed ... >> >> I don't get this. > > You are describing a transitioning over to DRM - which is Ok. > But on that way there is no need to ignore, deny or even kill usage scenarios > which are different compared to your usage scenarios (e.g. embedded devices, > old platforms, slow devices, slow busses, no 3D hardware features, > low-color devices, ...). And none of those examples is out-ruled by DRM. In fact we do support devices that fall in those categories. This is last week's discussion all over again. Best regards Thomas > > Helge
On Wed, Jan 26, 2022 at 12:31:21PM +0100, Helge Deller wrote: > On 1/26/22 12:18, Javier Martinez Canillas wrote: > > On 1/26/22 11:59, Helge Deller wrote: > >> On 1/26/22 11:02, Andy Shevchenko wrote: > > > > [snip] > > > >>> P.S. For the record, I will personally NAK any attempts to remove that > >>> driver from the kernel. And this is another point why it's better not > >>> to be under the staging. > >> > >> I agree. Same as for me to NAK the disabling of fbcon's acceleration > >> features or even attempting to remove fbdev altogether (unless all > >> relevant drivers are ported to DRM). > >> > > > > But that will never happen if we keep moving the goal post. > > > > At some point new fbdev drivers should not be added anymore, otherwise > > the number of existing drivers that need conversion will keep growing. > > Good point, and yes you are right! > > I think the rule should be something like: > > New graphics devices (e.g. max. 3 years old from now) usually are > capable to be ported to DRM. > For those graphics cards we should put a hard stop and not include them > as new driver into the fbdev framework. Inclusion for those will only > happen as DRM driver. We made this rule 6 years ago already. thanks, greg k-h
Hi Am 26.01.22 um 11:59 schrieb Helge Deller: > On 1/26/22 11:02, Andy Shevchenko wrote: >> On Wed, Jan 26, 2022 at 10:52 AM Thomas Zimmermann <tzimmermann@suse.de> wrote: >>> Am 25.01.22 um 21:21 schrieb Andy Shevchenko: >>>> Since we got a maintainer for fbdev, I would like to >>>> unorphan fbtft (with the idea of sending PRs to Helge) >>>> and move it out of staging since there is no more clean >>>> up work expected and no more drivers either. >>>> >>>> Thoughts? > > Personally I'm in favour of this proposal and would be happy > to take patches for it through the fbdev git tree. > Reasoning below... > >>> But why? We already have DRM drivers for some of these devices. >> >> No, we do not (only a few are available). > > seems to be 2 out of 10 (according to the other mails) FYI it's ili9163 and hx8357d. Both of those are of the same size ('wc -l') on DRM and fbdev: 200 to 300 loc. >>> Porting the others to DRM is such a better long-term plan. OTOH, >>> as no one has shown up and converted them, maybe they should be >>> left dead or removed entirely. >> >> As I mentioned above there are devices that nobody will take time to >> port to a way too complex DRM subsystem. But the devices are cheap and >> quite widespread in the embedded world. I'm in possession of 3 or 4 >> different models and only 1 is supported by tiny DRM. >> >> On top of that the subtle fact people forgot about FBTFT is that it >> does support parallel interface (yes, I know that it's not performant, >> but one of the displays I have is with that type of interface). > > I don't know those devices, but it seems they are still being used. > > And the reasons why they have not been ported to DRM yet is > likely because either lack of man-power, a slow-down with DRM (due to > slow bus connections or increased memory usage with DRM), or > simply that it's used in embedded-like scenarios with a limited > set of userspace applications for which existing fbdev access is sufficient. > > Again, I don't know the reason for this specific devices, but I know > of other devices for which those reasons above are valid. > Just the example I posted yesterday where a simple "time dmesg" needed > unaccelerated 19 seconds compared to 2 seconds with acceleration. > So, as long as acceleration isn't possible with that driver in > DRM, DRM isn't a preferred target where the driver should be ported. > > So, I'd be fine to take it into fbdev tree. > > Interestingly there is another fbdev driver in staging (sm750fb) with > similiar issues. The TODO mentions a porting to DRM which happens at > https://gitlab.com/sudipm/sm750/tree/sm750 > but the last commit there is 3 years ago. I don't know why it wasn't > continued yet. It's always for the same reason: the hw is old and devs have moved on. Best regards Thomas
Hi Am 26.01.22 um 12:31 schrieb Helge Deller: > On 1/26/22 12:18, Javier Martinez Canillas wrote: >> On 1/26/22 11:59, Helge Deller wrote: >>> On 1/26/22 11:02, Andy Shevchenko wrote: >> >> [snip] >> >>>> P.S. For the record, I will personally NAK any attempts to remove that >>>> driver from the kernel. And this is another point why it's better not >>>> to be under the staging. >>> >>> I agree. Same as for me to NAK the disabling of fbcon's acceleration >>> features or even attempting to remove fbdev altogether (unless all >>> relevant drivers are ported to DRM). >>> >> >> But that will never happen if we keep moving the goal post. >> >> At some point new fbdev drivers should not be added anymore, otherwise >> the number of existing drivers that need conversion will keep growing. > > Good point, and yes you are right! > > I think the rule should be something like: > > New graphics devices (e.g. max. 3 years old from now) usually are > capable to be ported to DRM. > For those graphics cards we should put a hard stop and not include them > as new driver into the fbdev framework. Inclusion for those will only > happen as DRM driver. > > In the same manner there are old graphic cards or very specific devices > (e.g. more than 3 years old or only used in niche-use cases) > which have limitations and thus can't easily be ported to DRM. > For those it's still acceptable to include them as legacy fbdev driver, > because the work needed in DRM to support such cards or to be able that > they run fast enough with DRM just doesn't pay off the efforts which are > needed to keep them as DRM driver. > > Would that be acceptable? No. As we've said several times, there's nothing stopping any device from being supported by DRM. If something's missing or slow, it's because no one has had that issue so far. We welcome patches patches to fix such problems. Best regards Thomas > > Helge
On Wed, Jan 26, 2022 at 12:51:46PM +0100, Helge Deller wrote: > On 1/26/22 12:38, Greg Kroah-Hartman wrote: > > On Wed, Jan 26, 2022 at 12:31:21PM +0100, Helge Deller wrote: > >> On 1/26/22 12:18, Javier Martinez Canillas wrote: > >>> On 1/26/22 11:59, Helge Deller wrote: > >>>> On 1/26/22 11:02, Andy Shevchenko wrote: > >>> > >>> [snip] > >>> > >>>>> P.S. For the record, I will personally NAK any attempts to remove that > >>>>> driver from the kernel. And this is another point why it's better not > >>>>> to be under the staging. > >>>> > >>>> I agree. Same as for me to NAK the disabling of fbcon's acceleration > >>>> features or even attempting to remove fbdev altogether (unless all > >>>> relevant drivers are ported to DRM). > >>>> > >>> > >>> But that will never happen if we keep moving the goal post. > >>> > >>> At some point new fbdev drivers should not be added anymore, otherwise > >>> the number of existing drivers that need conversion will keep growing. > >> > >> Good point, and yes you are right! > >> > >> I think the rule should be something like: > >> > >> New graphics devices (e.g. max. 3 years old from now) usually are > >> capable to be ported to DRM. > >> For those graphics cards we should put a hard stop and not include them > >> as new driver into the fbdev framework. Inclusion for those will only > >> happen as DRM driver. > > > > We made this rule 6 years ago already. > > Very good. > > Was there any decision how to handle drivers which can't use DRM, > or for which DRM doesn't make sense? We fix up DRM to handle such devices. > So the best way forward regarding those fbtft drivers is probably what > you suggested: Split them and move those DRM-capable drivers to DRM, > the others to fbdev, right? No, port those that work to DRM and just delete the rest as no one is using them. thanks, greg k-h
On Wed, Jan 26, 2022 at 01:37:00PM +0100, Javier Martinez Canillas wrote: > On 1/26/22 11:28, Dan Carpenter wrote: > > On Wed, Jan 26, 2022 at 12:04:26PM +0200, Andy Shevchenko wrote: > >> On Wed, Jan 26, 2022 at 12:02 PM Andy Shevchenko > >> <andy.shevchenko@gmail.com> wrote: > >>> On Wed, Jan 26, 2022 at 10:52 AM Thomas Zimmermann <tzimmermann@suse.de> wrote: > >>>> Am 25.01.22 um 21:21 schrieb Andy Shevchenko: > >> > >> ... > >> > >>>> But why? We already have DRM drivers for some of these devices. > >>> > >>> No, we do not (only a few are available). > >> > >> Sorry, I missed your word 'some'. Some == almost none from the list (I > >> don't remember exact numbers but something like 2 out of 10 are > >> supported by tiny DRM and see about interfaces). > > > > Could we get an exact list? > > > > The list AFAICT is the following. I'm not familiar with these so please > feel free to correct anything I got wrong here. > > I've marked with '?' if found references to the device supported by the > fbdev driver in a DRM driver, but it's not clear if support the same HW. > > Drivers in drivers/staging/fbtft: > > fb_agm1264k-fl.c > fb_bd663474.c > fb_hx8340bn.c > fb_hx8347d.c (DRM driver in drivers/gpu/drm/tiny/hx8357d.c) > fb_hx8353d.c > fb_hx8357d.c (DRM driver in drivers/gpu/drm/tiny/hx8357d.c) > fb_ili9163.c (DRM driver in drivers/gpu/drm/tiny/ili9163.c) > fb_ili9320.c > fb_ili9325.c > fb_ili9340.c (DRM driver in drivers/gpu/drm/tiny/mi0283qt.c ?) > fb_ili9341.c (DRM driver in drivers/gpu/drm/tiny/mi0283qt.c ?) > fb_ili9481.c > fb_ili9486.c (DRM driver in drivers/gpu/drm/tiny/ili9486.c) > fb_pcd8544.c > fb_ra8875.c > fb_s6d02a1.c > fb_s6d1121.c > fb_seps525.c > fb_sh1106.c > fb_ssd1289.c > fb_ssd1305.c > fb_ssd1306.c > fb_ssd1325.c > fb_ssd1331.c > fb_ssd1351.c > fb_st7735r.c (DRM driver in drivers/gpu/drm/tiny/st7735r.c) > fb_st7789v.c (DRM driver in drivers/gpu/drm/panel/panel-sitronix-st7789v.c) I'll gladly take a patch that deletes the fb_* files that are already handled by a DRM driver like you list here. thanks, greg k-h
On Wed, Jan 26, 2022 at 11:31:45AM +0100, Daniel Vetter wrote: > On Wed, Jan 26, 2022 at 9:31 AM Greg Kroah-Hartman > <gregkh@linuxfoundation.org> wrote: > > On Tue, Jan 25, 2022 at 10:21:14PM +0200, Andy Shevchenko wrote: ... > > I'm ok with the files moving if the dri developers agree with it. It's > > up to them, not me. > > On one hand I'm happy anytime someone volunteers to help out. > > On the other hand ... why does it have to be resurrecting fbdev? > There's an entire community of people who really know graphics and > display and spent considerable amount of effort on creating useful and > documented helpers for pretty much anything you might ever want to do. Why nobody has converted these drivers to be DRM based? For all these years no new conversion happens except couple, which I don't even have a hardware to see. But I have the hardware that is supported exclusively by fbtft driver. > And somehow we have to go back to typing out things the hard way, with > full verbosity, for an uapi that distros are abandoning (e.g. even for > sdl the direction is to run it on top of drm with a compat layer, > afaiui fedora is completely ditching any userspace that still even > uses /dev/fb/0). And yes I know there's still some gaps in drm, > largely for display features which were really en vogue about 20 years > ago. And we're happy to add that support, if someone who still has > such hardware can put in the little bit of work needed ... > > I don't get this. I don't get how Fedora is related here. It's not useful to bury the /dev/fbX out for the devices that the use of are black-and-white output on small embedded systems.
On Wed, Jan 26, 2022 at 12:26:36PM +0100, Greg Kroah-Hartman wrote: > On Wed, Jan 26, 2022 at 12:17:08PM +0100, Helge Deller wrote: > > On 1/26/22 11:31, Daniel Vetter wrote: ... > > You are describing a transitioning over to DRM - which is Ok. > > But on that way there is no need to ignore, deny or even kill usage scenarios > > which are different compared to your usage scenarios (e.g. embedded devices, > > old platforms, slow devices, slow busses, no 3D hardware features, > > low-color devices, ...). > > All of those should be handled by the drm layer, as Daniel keeps > pointing out. If not, then the tinydrm layer needs to be enhanced to do > so. > > Anyone have a pointer to hardware I can buy that is one of these fbtft > drivers that I could do a port to drm to see just how much work is > really needed here? I have bought myself (for other purposes, I mean not to convert the driver(s)) SSD1306 based display (SPI), SSD1331 (SPI), HX88347d (parallel). Each of them costed less than $10 with delivery to EU (nowadays maybe a bit more expensive). I believe it's very easy to find the links on AliExpress.
On Wed, Jan 26, 2022 at 12:31:40PM +0100, Thomas Zimmermann wrote: > Am 26.01.22 um 12:17 schrieb Helge Deller: ... > And none of those examples is out-ruled by DRM. In fact we do support > devices that fall in those categories. > > This is last week's discussion all over again. Fine, write a driver or accept existing solution. While there is no other solution, let's go with the existing.
On Wed, Jan 26, 2022 at 01:37:00PM +0100, Javier Martinez Canillas wrote: > On 1/26/22 11:28, Dan Carpenter wrote: > > On Wed, Jan 26, 2022 at 12:04:26PM +0200, Andy Shevchenko wrote: > >> On Wed, Jan 26, 2022 at 12:02 PM Andy Shevchenko > >> <andy.shevchenko@gmail.com> wrote: > >>> On Wed, Jan 26, 2022 at 10:52 AM Thomas Zimmermann <tzimmermann@suse.de> wrote: > >>>> Am 25.01.22 um 21:21 schrieb Andy Shevchenko: > >> > >> ... > >> > >>>> But why? We already have DRM drivers for some of these devices. > >>> > >>> No, we do not (only a few are available). > >> > >> Sorry, I missed your word 'some'. Some == almost none from the list (I > >> don't remember exact numbers but something like 2 out of 10 are > >> supported by tiny DRM and see about interfaces). > > > > Could we get an exact list? > > > > The list AFAICT is the following. I'm not familiar with these so please > feel free to correct anything I got wrong here. > > I've marked with '?' if found references to the device supported by the > fbdev driver in a DRM driver, but it's not clear if support the same HW. > > Drivers in drivers/staging/fbtft: Thanks! Note, there is no support for the devices with parallel interface in the DRM. So, basically we can't kill even a single one from fbtft if there is a user for it. > fb_agm1264k-fl.c > fb_bd663474.c > fb_hx8340bn.c > fb_hx8347d.c (DRM driver in drivers/gpu/drm/tiny/hx8357d.c) > fb_hx8353d.c > fb_hx8357d.c (DRM driver in drivers/gpu/drm/tiny/hx8357d.c) > fb_ili9163.c (DRM driver in drivers/gpu/drm/tiny/ili9163.c) > fb_ili9320.c > fb_ili9325.c > fb_ili9340.c (DRM driver in drivers/gpu/drm/tiny/mi0283qt.c ?) Not sure. > fb_ili9341.c (DRM driver in drivers/gpu/drm/tiny/mi0283qt.c ?) Yes and for the fact there are two drivers for the same chip in the DRM. Overall there are three different drivers for Ilitek 9341. > fb_ili9481.c > fb_ili9486.c (DRM driver in drivers/gpu/drm/tiny/ili9486.c) > fb_pcd8544.c > fb_ra8875.c > fb_s6d02a1.c > fb_s6d1121.c > fb_seps525.c > fb_sh1106.c > fb_ssd1289.c > fb_ssd1305.c > fb_ssd1306.c > fb_ssd1325.c > fb_ssd1331.c > fb_ssd1351.c > fb_st7735r.c (DRM driver in drivers/gpu/drm/tiny/st7735r.c) > fb_st7789v.c (DRM driver in drivers/gpu/drm/panel/panel-sitronix-st7789v.c) > fb_tinylcd.c > fb_tls8204.c > fb_uc1611.c > fb_uc1701.c > fb_upd161704.c > fb_watterott.c
On Wed, Jan 26, 2022 at 01:56:11PM +0100, Greg Kroah-Hartman wrote: > On Wed, Jan 26, 2022 at 01:37:00PM +0100, Javier Martinez Canillas wrote: > > On 1/26/22 11:28, Dan Carpenter wrote: ... > > fb_hx8347d.c (DRM driver in drivers/gpu/drm/tiny/hx8357d.c) > > fb_hx8357d.c (DRM driver in drivers/gpu/drm/tiny/hx8357d.c) > > fb_ili9163.c (DRM driver in drivers/gpu/drm/tiny/ili9163.c) > > fb_ili9341.c (DRM driver in drivers/gpu/drm/tiny/mi0283qt.c ?) > > fb_ili9486.c (DRM driver in drivers/gpu/drm/tiny/ili9486.c) > > fb_st7735r.c (DRM driver in drivers/gpu/drm/tiny/st7735r.c) > > fb_st7789v.c (DRM driver in drivers/gpu/drm/panel/panel-sitronix-st7789v.c) > > I'll gladly take a patch that deletes the fb_* files that are already > handled by a DRM driver like you list here. None of the DRM driver supports parallel interface for these devices.
Hi, On Wed, 26 Jan 2022 at 13:08, Andy Shevchenko <andriy.shevchenko@linux.intel.com> wrote: > It's not useful to bury the /dev/fbX out for the devices that > the use of are black-and-white output on small embedded systems. It's not useful to decide that such systems should only be supported by a subsystem which has been deprecated for a long time and which has little userspace support. It's also not useful to spend time working on that subsystem, rather than the one everyone has agreed on for the last 15 years, is supported by userspace, is expressive, and has a kernel subsystem which isn't a forest of CVEs and broken locking. Cheers, Daniel
On Wed, Jan 26, 2022 at 11:52:16AM +0100, Daniel Vetter wrote: > On Wed, Jan 26, 2022 at 11:47 AM Greg Kroah-Hartman > <gregkh@linuxfoundation.org> wrote: > > On Wed, Jan 26, 2022 at 12:02:36PM +0200, Andy Shevchenko wrote: > > > On Wed, Jan 26, 2022 at 10:52 AM Thomas Zimmermann <tzimmermann@suse.de> wrote: > > > > Am 25.01.22 um 21:21 schrieb Andy Shevchenko: > > > > > Since we got a maintainer for fbdev, I would like to > > > > > unorphan fbtft (with the idea of sending PRs to Helge) > > > > > and move it out of staging since there is no more clean > > > > > up work expected and no more drivers either. > > > > > > > > > > Thoughts? > > > > > > Thanks for sharing yours, my answers below. > > > > > > > But why? We already have DRM drivers for some of these devices. > > > > > > No, we do not (only a few are available). > > > > > > > Porting > > > > the others to DRM is such a better long-term plan. OTOH, as no one has > > > > shown up and converted them, maybe they should be left dead or removed > > > > entirely. > > > > > > As I mentioned above there are devices that nobody will take time to > > > port to a way too complex DRM subsystem. But the devices are cheap and > > > quite widespread in the embedded world. I'm in possession of 3 or 4 > > > different models and only 1 is supported by tiny DRM. > > > > Great, then let's just move the 2 models that you do not have support > > for in DRM, not the whole lot. When we have real users for the drivers, > > we can move them out of staging, but until then, dragging all of them > > out does not make sense. > > Can't we create drm drivers for these 2-3 models? Like we have drivers > which are below 300 lines with all the helpers taking care of > everything, this shouldn't be too tricky. For a few years there is no news about it. Okay, in this thread Noralf revealed a new idea to replace pile of the drivers in FBTFT. > And if no one cares enough for that, then imo let's just keep this in > staging and let it quietly&slowly pass away. At least from the people > who've been active in any kind of display development the past 6+ > years (which is roughly when Tomi abandoned fbdev as last active > maintainer) the consensus _is_ that drm drivers are simpler, quicker > to type (once you got hold of the subsystem and all its helpers at > least), and adding new fbdev drivers just makes no sense at all.
On Wed, Jan 26, 2022 at 12:15:48PM +0100, Greg Kroah-Hartman wrote: > On Wed, Jan 26, 2022 at 11:52:16AM +0100, Daniel Vetter wrote: > > On Wed, Jan 26, 2022 at 11:47 AM Greg Kroah-Hartman > > <gregkh@linuxfoundation.org> wrote: > > > On Wed, Jan 26, 2022 at 12:02:36PM +0200, Andy Shevchenko wrote: > > > > On Wed, Jan 26, 2022 at 10:52 AM Thomas Zimmermann <tzimmermann@suse.de> wrote: > > > > > Am 25.01.22 um 21:21 schrieb Andy Shevchenko: > > > > > > Since we got a maintainer for fbdev, I would like to > > > > > > unorphan fbtft (with the idea of sending PRs to Helge) > > > > > > and move it out of staging since there is no more clean > > > > > > up work expected and no more drivers either. > > > > > > > > > > > > Thoughts? > > > > > > > > Thanks for sharing yours, my answers below. > > > > > > > > > But why? We already have DRM drivers for some of these devices. > > > > > > > > No, we do not (only a few are available). > > > > > > > > > Porting > > > > > the others to DRM is such a better long-term plan. OTOH, as no one has > > > > > shown up and converted them, maybe they should be left dead or removed > > > > > entirely. > > > > > > > > As I mentioned above there are devices that nobody will take time to > > > > port to a way too complex DRM subsystem. But the devices are cheap and > > > > quite widespread in the embedded world. I'm in possession of 3 or 4 > > > > different models and only 1 is supported by tiny DRM. > > > > > > Great, then let's just move the 2 models that you do not have support > > > for in DRM, not the whole lot. When we have real users for the drivers, > > > we can move them out of staging, but until then, dragging all of them > > > out does not make sense. > > > > Can't we create drm drivers for these 2-3 models? Like we have drivers > > which are below 300 lines with all the helpers taking care of > > everything, this shouldn't be too tricky. > > Agreed, having the hardware to test this with is the hardest part. > Andy, this should be better to do in the longrun than trying to keep > these other drivers "alive". I see, I'm not objecting the place, I'm objecting blind removal, so as far as the drivers, for which there is no alternative in the tree, are in the tree (even in the staging) it's fine. Let's keep a status quo then.
On Wed, Jan 26, 2022 at 12:18:30PM +0100, Javier Martinez Canillas wrote: > On 1/26/22 11:59, Helge Deller wrote: > > On 1/26/22 11:02, Andy Shevchenko wrote: > > [snip] > > >> P.S. For the record, I will personally NAK any attempts to remove that > >> driver from the kernel. And this is another point why it's better not > >> to be under the staging. > > > > I agree. Same as for me to NAK the disabling of fbcon's acceleration > > features or even attempting to remove fbdev altogether (unless all > > relevant drivers are ported to DRM). > > > > But that will never happen if we keep moving the goal post. > > At some point new fbdev drivers should not be added anymore, otherwise > the number of existing drivers that need conversion will keep growing. This thread is not about adding a new driver.
On Wed, Jan 26, 2022 at 12:38:09PM +0100, Helge Deller wrote: > On 1/26/22 12:24, Daniel Vetter wrote: > > On Wed, Jan 26, 2022 at 12:18 PM Javier Martinez Canillas > > <javierm@redhat.com> wrote: > >> On 1/26/22 11:59, Helge Deller wrote: > >>> On 1/26/22 11:02, Andy Shevchenko wrote: ... > >>>> P.S. For the record, I will personally NAK any attempts to remove that > >>>> driver from the kernel. And this is another point why it's better not > >>>> to be under the staging. > >>> > >>> I agree. Same as for me to NAK the disabling of fbcon's acceleration > >>> features or even attempting to remove fbdev altogether (unless all > >>> relevant drivers are ported to DRM). > >> > >> But that will never happen if we keep moving the goal post. > >> > >> At some point new fbdev drivers should not be added anymore, otherwise > >> the number of existing drivers that need conversion will keep growing. > > > > And that point was about 5 years ago, and has been discussed at some > > plumbers meanwhile, resulting in the staging TODO patches to make > > these drm drivers to destage them. > > > > Fixing bugs in fbdev is all fine, reopening it for merging new drivers is not. > > We are on the same page! > I'm not at all proposing to include new drivers for (relatively) new > hardware into fbdev, which is capable to be written as DRM driver. Agree. The point here is neither in opening it for new comers nor for expanding, the drivers in question are all in the kernel in different folder that is not suitable for them, but I gave up. I see that nobody wants maintainers to be appearing for the old _working_ code, as it was shown already by the DVB case few month ago.
On Wed, Jan 26, 2022 at 12:41:41PM +0100, Thomas Zimmermann wrote: > Am 26.01.22 um 11:59 schrieb Helge Deller: ... > It's always for the same reason: the hw is old and devs have moved on. It's pity to have a working system with an old hardware that no one in the kernel community gives a shit about because simply they are not in the same boat. Try to be on the people's position...
On Wed, Jan 26, 2022 at 02:19:37PM +0100, Javier Martinez Canillas wrote: > On 1/26/22 13:56, Greg Kroah-Hartman wrote: > >> fb_ili9341.c (DRM driver in drivers/gpu/drm/tiny/mi0283qt.c ?) > > This was a copy and paste error. It should had been: > > (DRM driver in drivers/gpu/drm/tiny/ili9341.c) They both fit.
On 1/26/22 14:18, Andy Shevchenko wrote: > On Wed, Jan 26, 2022 at 01:56:11PM +0100, Greg Kroah-Hartman wrote: >> On Wed, Jan 26, 2022 at 01:37:00PM +0100, Javier Martinez Canillas wrote: >>> On 1/26/22 11:28, Dan Carpenter wrote: > > ... > >>> fb_hx8347d.c (DRM driver in drivers/gpu/drm/tiny/hx8357d.c) >>> fb_hx8357d.c (DRM driver in drivers/gpu/drm/tiny/hx8357d.c) >>> fb_ili9163.c (DRM driver in drivers/gpu/drm/tiny/ili9163.c) >>> fb_ili9341.c (DRM driver in drivers/gpu/drm/tiny/mi0283qt.c ?) >>> fb_ili9486.c (DRM driver in drivers/gpu/drm/tiny/ili9486.c) >>> fb_st7735r.c (DRM driver in drivers/gpu/drm/tiny/st7735r.c) >>> fb_st7789v.c (DRM driver in drivers/gpu/drm/panel/panel-sitronix-st7789v.c) >> >> I'll gladly take a patch that deletes the fb_* files that are already >> handled by a DRM driver like you list here. > > None of the DRM driver supports parallel interface for these devices. > Thanks for the info. Then we can't remove any of these drivers indeed. Best regards,
On 1/26/22 14:12, Andy Shevchenko wrote: > On Wed, Jan 26, 2022 at 12:26:36PM +0100, Greg Kroah-Hartman wrote: >> On Wed, Jan 26, 2022 at 12:17:08PM +0100, Helge Deller wrote: >>> On 1/26/22 11:31, Daniel Vetter wrote: > > ... > >>> You are describing a transitioning over to DRM - which is Ok. >>> But on that way there is no need to ignore, deny or even kill usage scenarios >>> which are different compared to your usage scenarios (e.g. embedded devices, >>> old platforms, slow devices, slow busses, no 3D hardware features, >>> low-color devices, ...). >> >> All of those should be handled by the drm layer, as Daniel keeps >> pointing out. If not, then the tinydrm layer needs to be enhanced to do >> so. >> >> Anyone have a pointer to hardware I can buy that is one of these fbtft >> drivers that I could do a port to drm to see just how much work is >> really needed here? > > I have bought myself (for other purposes, I mean not to convert the driver(s)) > SSD1306 based display (SPI), SSD1331 (SPI), HX88347d (parallel). > I've just bought a SSD1306 (I2C) based one and will attempt to write a DRM driver using drivers/staging/fbtft/fb_ssd1306.c as a reference. I didn't find one with a SPI interface but we can later add a transport for that if I succeed. Best regards,
On 1/26/22 14:27, Andy Shevchenko wrote: > On Wed, Jan 26, 2022 at 12:18:30PM +0100, Javier Martinez Canillas wrote: >> On 1/26/22 11:59, Helge Deller wrote: >>> On 1/26/22 11:02, Andy Shevchenko wrote: >> >> [snip] >> >>>> P.S. For the record, I will personally NAK any attempts to remove that >>>> driver from the kernel. And this is another point why it's better not >>>> to be under the staging. >>> >>> I agree. Same as for me to NAK the disabling of fbcon's acceleration >>> features or even attempting to remove fbdev altogether (unless all >>> relevant drivers are ported to DRM). >>> >> >> But that will never happen if we keep moving the goal post. >> >> At some point new fbdev drivers should not be added anymore, otherwise >> the number of existing drivers that need conversion will keep growing. > > This thread is not about adding a new driver. > It was about adding a new drivers to drivers/video/ (taken from staging). Best regards,
On Wed, Jan 26, 2022 at 02:46:08PM +0100, Javier Martinez Canillas wrote: > On 1/26/22 14:12, Andy Shevchenko wrote: > > On Wed, Jan 26, 2022 at 12:26:36PM +0100, Greg Kroah-Hartman wrote: > >> On Wed, Jan 26, 2022 at 12:17:08PM +0100, Helge Deller wrote: > >>> On 1/26/22 11:31, Daniel Vetter wrote: > > > > ... > > > >>> You are describing a transitioning over to DRM - which is Ok. > >>> But on that way there is no need to ignore, deny or even kill usage scenarios > >>> which are different compared to your usage scenarios (e.g. embedded devices, > >>> old platforms, slow devices, slow busses, no 3D hardware features, > >>> low-color devices, ...). > >> > >> All of those should be handled by the drm layer, as Daniel keeps > >> pointing out. If not, then the tinydrm layer needs to be enhanced to do > >> so. > >> > >> Anyone have a pointer to hardware I can buy that is one of these fbtft > >> drivers that I could do a port to drm to see just how much work is > >> really needed here? > > > > I have bought myself (for other purposes, I mean not to convert the driver(s)) > > SSD1306 based display (SPI), SSD1331 (SPI), HX88347d (parallel). > > > > I've just bought a SSD1306 (I2C) based one and will attempt to write a DRM > driver using drivers/staging/fbtft/fb_ssd1306.c as a reference. You should take ssd1307fb.c instead. And basically create a MIPI based driver for I2C. Then we won't go same road again for other similar devices. > I didn't find one with a SPI interface but we can later add a transport for > that if I succeed.
On Wed, Jan 26, 2022 at 04:08:32PM +0200, Andy Shevchenko wrote: > On Wed, Jan 26, 2022 at 02:46:08PM +0100, Javier Martinez Canillas wrote: > > On 1/26/22 14:12, Andy Shevchenko wrote: ... > > I've just bought a SSD1306 (I2C) based one and will attempt to write a DRM > > driver using drivers/staging/fbtft/fb_ssd1306.c as a reference. > > You should take ssd1307fb.c instead. And basically create a MIPI based driver > for I2C. Then we won't go same road again for other similar devices. For the record it supports your device: static const struct i2c_device_id ssd1307fb_i2c_id[] = { { "ssd1305fb", 0 }, { "ssd1306fb", 0 }, { "ssd1307fb", 0 }, { "ssd1309fb", 0 },
On Wed, Jan 26, 2022 at 02:47:33PM +0100, Javier Martinez Canillas wrote: > On 1/26/22 14:27, Andy Shevchenko wrote: > > On Wed, Jan 26, 2022 at 12:18:30PM +0100, Javier Martinez Canillas wrote: > >> On 1/26/22 11:59, Helge Deller wrote: > >>> On 1/26/22 11:02, Andy Shevchenko wrote: ... > >>>> P.S. For the record, I will personally NAK any attempts to remove that > >>>> driver from the kernel. And this is another point why it's better not > >>>> to be under the staging. > >>> > >>> I agree. Same as for me to NAK the disabling of fbcon's acceleration > >>> features or even attempting to remove fbdev altogether (unless all > >>> relevant drivers are ported to DRM). > >> > >> But that will never happen if we keep moving the goal post. > >> > >> At some point new fbdev drivers should not be added anymore, otherwise > >> the number of existing drivers that need conversion will keep growing. > > > > This thread is not about adding a new driver. > > It was about adding a new drivers to drivers/video/ (taken from staging). Does it mean gates are open to take any new fbdev drivers to the staging? If not, I do not see a point here.
On 1/26/22 15:10, Andy Shevchenko wrote: > On Wed, Jan 26, 2022 at 04:08:32PM +0200, Andy Shevchenko wrote: >> On Wed, Jan 26, 2022 at 02:46:08PM +0100, Javier Martinez Canillas wrote: >>> On 1/26/22 14:12, Andy Shevchenko wrote: > > ... > >>> I've just bought a SSD1306 (I2C) based one and will attempt to write a DRM >>> driver using drivers/staging/fbtft/fb_ssd1306.c as a reference. >> >> You should take ssd1307fb.c instead. And basically create a MIPI based driver >> for I2C. Then we won't go same road again for other similar devices. > > For the record it supports your device: > > static const struct i2c_device_id ssd1307fb_i2c_id[] = { > { "ssd1305fb", 0 }, > { "ssd1306fb", 0 }, > { "ssd1307fb", 0 }, > { "ssd1309fb", 0 }, > > Thanks a lot for the pointer. I was only looking at drivers/staging and didn't check drivers/video. I'll try to convert that one then once I get the display. Best regards,
On 1/26/22 15:11, Andy Shevchenko wrote: > On Wed, Jan 26, 2022 at 02:47:33PM +0100, Javier Martinez Canillas wrote: >> On 1/26/22 14:27, Andy Shevchenko wrote: >>> On Wed, Jan 26, 2022 at 12:18:30PM +0100, Javier Martinez Canillas wrote: >>>> On 1/26/22 11:59, Helge Deller wrote: >>>>> On 1/26/22 11:02, Andy Shevchenko wrote: > > ... > >>>>>> P.S. For the record, I will personally NAK any attempts to remove that >>>>>> driver from the kernel. And this is another point why it's better not >>>>>> to be under the staging. >>>>> >>>>> I agree. Same as for me to NAK the disabling of fbcon's acceleration >>>>> features or even attempting to remove fbdev altogether (unless all >>>>> relevant drivers are ported to DRM). >>>> >>>> But that will never happen if we keep moving the goal post. >>>> >>>> At some point new fbdev drivers should not be added anymore, otherwise >>>> the number of existing drivers that need conversion will keep growing. >>> >>> This thread is not about adding a new driver. >> >> It was about adding a new drivers to drivers/video/ (taken from staging). > > Does it mean gates are open to take any new fbdev drivers to the staging? > If not, I do not see a point here. > Good question. I don't know really. But staging has always been more flexible in what's accepted there and that's why some distros avoid to enable CONFIG_STAGING=y in the kernel. Best regards,
On Wed, Jan 26, 2022 at 03:18:14PM +0100, Javier Martinez Canillas wrote: > On 1/26/22 15:11, Andy Shevchenko wrote: > > On Wed, Jan 26, 2022 at 02:47:33PM +0100, Javier Martinez Canillas wrote: > >> On 1/26/22 14:27, Andy Shevchenko wrote: > >>> On Wed, Jan 26, 2022 at 12:18:30PM +0100, Javier Martinez Canillas wrote: > >>>> On 1/26/22 11:59, Helge Deller wrote: > >>>>> On 1/26/22 11:02, Andy Shevchenko wrote: > > > > ... > > > >>>>>> P.S. For the record, I will personally NAK any attempts to remove that > >>>>>> driver from the kernel. And this is another point why it's better not > >>>>>> to be under the staging. > >>>>> > >>>>> I agree. Same as for me to NAK the disabling of fbcon's acceleration > >>>>> features or even attempting to remove fbdev altogether (unless all > >>>>> relevant drivers are ported to DRM). > >>>> > >>>> But that will never happen if we keep moving the goal post. > >>>> > >>>> At some point new fbdev drivers should not be added anymore, otherwise > >>>> the number of existing drivers that need conversion will keep growing. > >>> > >>> This thread is not about adding a new driver. > >> > >> It was about adding a new drivers to drivers/video/ (taken from staging). > > > > Does it mean gates are open to take any new fbdev drivers to the staging? > > If not, I do not see a point here. > > > > Good question. I don't know really. > > But staging has always been more flexible in what's accepted there and > that's why some distros avoid to enable CONFIG_STAGING=y in the kernel. And that's why if you load a staging driver, it enables TAINT_CRAP in your runtime flags :)
The other advantage of staging is the I don't think syzbot enables it. I guess it's easier to persuade Dmitry to ignore STAGING than it was to get him to disable FBDEV. :P The memory corruption in fbdev was a real headache for everyone because the stack traces ended up all over the kernel. regards, dan carpenter
Hi Am 26.01.22 um 14:32 schrieb Andy Shevchenko: > On Wed, Jan 26, 2022 at 12:41:41PM +0100, Thomas Zimmermann wrote: >> Am 26.01.22 um 11:59 schrieb Helge Deller: > > ... > > >> It's always for the same reason: the hw is old and devs have moved on. > > It's pity to have a working system with an old hardware that no one in > the kernel community gives a shit about because simply they are not in > the same boat. Try to be on the people's position... Yes, I do care about old hardware. I made helpers for converting fbdev drivers to DRM. I even made the initial commits for those drivers where I could find the HW on Ebay. [1] I made sure that every single of them at least gets fbcon onto the screen. So interested devs could start immediately. Yet, no one ever showed up to convert even a single driver. As it stands, 90s PCI hardware is currently supported by DRM's simpledrm as long as the device has VESA. The performance is at least usable on AthlonXP-era computers. Now the owners of these devices at least have a chance of using modern graphics userspace. That userspace is important: graphics drivers don't live in a vacuum. There's no point in having one if it requires extra support from all other components. And there's more: * Occasionally, fbdev gets in the way of DRM. Just this week, we fixed a related bug. [2] * Fbdev's mmap semantics is the reason why it's hard to do fast in DRM. * Maintaining both stacks, DRM and fbdev, adds work to kernel, userspace and distro devs. Therefore, anything we do that keeps fbdev alive is a step backwards and a burden on the overall Linux graphics community. Please excuse my ranting, but fbdev proponents seem to be ignorant to all these points. It's apparently all about 'my console is slow'. Best regards Thomas [1] https://gitlab.freedesktop.org/tzimmermann/linux/-/tree/fbconv-plus-drivers [2] https://lore.kernel.org/dri-devel/16f9e064-99cc-4205-d03e-ae41ed034309@redhat.com/T/#t >
On Wed, Jan 26, 2022 at 04:02:23PM +0100, Thomas Zimmermann wrote: > Am 26.01.22 um 14:32 schrieb Andy Shevchenko: > > On Wed, Jan 26, 2022 at 12:41:41PM +0100, Thomas Zimmermann wrote: > > > Am 26.01.22 um 11:59 schrieb Helge Deller: > > > It's always for the same reason: the hw is old and devs have moved on. > > > > It's pity to have a working system with an old hardware that no one in > > the kernel community gives a shit about because simply they are not in > > the same boat. Try to be on the people's position... > > Yes, I do care about old hardware. I made helpers for converting fbdev > drivers to DRM. I even made the initial commits for those drivers where I > could find the HW on Ebay. [1] I made sure that every single of them at > least gets fbcon onto the screen. So interested devs could start > immediately. Thanks for doing that, I at least appreciate it. > Yet, no one ever showed up to convert even a single driver. I have helper in a limited way to test / enable drivers on some platforms where it wasn't possible before (you can easily see what I have done by running `git log --oneline --author="Andy Shevchenko" -- drivers/video drivers/gpu/drm drivers/staging/fbtft`), but DRM is completely new subsystem to me if we talk about driver conversion or so.
On 1/26/22 16:02, Thomas Zimmermann wrote: > Hi > > Am 26.01.22 um 14:32 schrieb Andy Shevchenko: >> On Wed, Jan 26, 2022 at 12:41:41PM +0100, Thomas Zimmermann wrote: >>> Am 26.01.22 um 11:59 schrieb Helge Deller: >> >> ... >> >> >>> It's always for the same reason: the hw is old and devs have moved on. >> >> It's pity to have a working system with an old hardware that no one in >> the kernel community gives a shit about because simply they are not in >> the same boat. Try to be on the people's position... > > Yes, I do care about old hardware. Yes, I know. I saw various articles about it. > I made helpers for converting fbdev drivers to DRM. I even made the > initial commits for those drivers where I could find the HW on Ebay. [1]> [1] https://gitlab.freedesktop.org/tzimmermann/linux/-/tree/fbconv-plus-drivers Just out of curiosity, does the tgui driver you patched there is now supported by DRM? I couldn't find it (just the tridentfb fbdev driver), so I assume it's somehow handled by simpledrm instead? > I made sure that every single of them at least gets fbcon onto the > screen. So interested devs could start immediately. Yet, no one ever > showed up to convert even a single driver. Both Geert wrote about that he was trying to convert a driver. The same is true for Sven where he came up with a prelimarary visualizefx driver... Both had issues which currently prevent that those drivers get finished. > As it stands, 90s PCI hardware is currently supported by DRM's > simpledrm as long as the device has VESA. Good. Some of the drivers in fbdev are for non-x86 architectures and don't have a VESA BIOS. Is is possible that simpledrm could (theoretically) support those too? > The performance is at least usable on AthlonXP-era computers. Now the > owners of these devices at least have a chance of using modern > graphics userspace. Yes. > That userspace is important: graphics drivers don't live in a vacuum. > There's no point in having one if it requires extra support from all > other components. And there's more: > > Â * Occasionally, fbdev gets in the way of DRM. Just this week, we fixed a related bug. [2] > > Â * Fbdev's mmap semantics is the reason why it's hard to do fast in DRM. > > Â * Maintaining both stacks, DRM and fbdev, adds work to kernel, userspace and distro devs. > > Therefore, anything we do that keeps fbdev alive is a step backwards and a burden on the overall Linux graphics community. That's understood and I don't disagree. The earlier drivers are converted to DRM the better. I probably don't even have any issues with dropping fbdev & drivers for the x86, ARM64, s390x & ppc64 platforms - I think many older cards aren't used either used (anymore), or your simpledrm may cover the most common cards. I think the patches we currently jointly develop to disable fbcon acceleration is exactly going into this direction. The problems I see are mostly on non-x86 architectures or corner-case usages like embedded devices or special machines. They may be oldish, but still being used. Those machines would completely loose their console without fbdev. > Please excuse my ranting, but fbdev proponents seem to be ignorant to > all these points. It's apparently all about 'my console is slow'. Your ranting is fair, but I wouldn't say I'm ignorant to your arguments. Of course performance is relevant, or would you exchange your car which today is capable to drive 100 mph with another car which only drives a maximum 10 mph? (Yes, that's around the factor of speed decrease I see). Or even worse: suddenly not being allowed/able to drive your car at all? Helge
On Wed, 26 Jan 2022, Andy Shevchenko <andriy.shevchenko@linux.intel.com> wrote:
> And basically create a MIPI based driver for I2C.
What does that even mean?
BR,
Jani.
dOn Wed, Jan 26, 2022 at 3:46 PM Dan Carpenter <dan.carpenter@oracle.com> wrote: > > The other advantage of staging is the I don't think syzbot enables it. > I guess it's easier to persuade Dmitry to ignore STAGING than it was to > get him to disable FBDEV. :P > > The memory corruption in fbdev was a real headache for everyone because > the stack traces ended up all over the kernel. Uh Dmitry disabled all of FBDEV? That's a bit too much, since there's still a lot of distros shipping things. I don't recommend enabling neither fbdev nor fbcon and some hardening checks look for these (forgot which one). But if syzbot stops checking fbcon and fbdev stuff on top of drm drivers (where most of the problems should be gone because you can't change the resolution through the current fbdev emulation) then that essentially means fbdev really needs to be disabled in distros asap. Disabling the entire pile of hw drivers makes sense, because that's pretty hopeless imo. Adding Dmitry to confirm. -Daniel -- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch
On Wed, Jan 26, 2022 at 3:24 PM Greg Kroah-Hartman <gregkh@linuxfoundation.org> wrote: > On Wed, Jan 26, 2022 at 03:18:14PM +0100, Javier Martinez Canillas wrote: > > On 1/26/22 15:11, Andy Shevchenko wrote: > > > On Wed, Jan 26, 2022 at 02:47:33PM +0100, Javier Martinez Canillas wrote: > > >> On 1/26/22 14:27, Andy Shevchenko wrote: > > >>> On Wed, Jan 26, 2022 at 12:18:30PM +0100, Javier Martinez Canillas wrote: > > >>>> On 1/26/22 11:59, Helge Deller wrote: > > >>>>> On 1/26/22 11:02, Andy Shevchenko wrote: > > > > > > ... > > > > > >>>>>> P.S. For the record, I will personally NAK any attempts to remove that > > >>>>>> driver from the kernel. And this is another point why it's better not > > >>>>>> to be under the staging. > > >>>>> > > >>>>> I agree. Same as for me to NAK the disabling of fbcon's acceleration > > >>>>> features or even attempting to remove fbdev altogether (unless all > > >>>>> relevant drivers are ported to DRM). > > >>>> > > >>>> But that will never happen if we keep moving the goal post. > > >>>> > > >>>> At some point new fbdev drivers should not be added anymore, otherwise > > >>>> the number of existing drivers that need conversion will keep growing. > > >>> > > >>> This thread is not about adding a new driver. > > >> > > >> It was about adding a new drivers to drivers/video/ (taken from staging). > > > > > > Does it mean gates are open to take any new fbdev drivers to the staging? > > > If not, I do not see a point here. > > > > > > > Good question. I don't know really. > > > > But staging has always been more flexible in what's accepted there and > > that's why some distros avoid to enable CONFIG_STAGING=y in the kernel. > > And that's why if you load a staging driver, it enables TAINT_CRAP in > your runtime flags :) fwiw I'm fine with adding new fbdev drivers to staging, that really doesn't hurt anyone. Adding drm drivers to staging tends to be pain, least because if we need to do any changes to helpers there's a cross-tree cordination problem usually, and the benefit of staging hasn't in the past really outweighted that. Plus I try for us to land new drivers when they're good enough directly into drivers/gpu, and not aim for perfect. -Daniel
On Wed, Jan 26, 2022 at 11:31:02PM +0100, Daniel Vetter wrote: > dOn Wed, Jan 26, 2022 at 3:46 PM Dan Carpenter <dan.carpenter@oracle.com> wrote: > > > > The other advantage of staging is the I don't think syzbot enables it. > > I guess it's easier to persuade Dmitry to ignore STAGING than it was to > > get him to disable FBDEV. :P > > > > The memory corruption in fbdev was a real headache for everyone because > > the stack traces ended up all over the kernel. > > Uh Dmitry disabled all of FBDEV? No that's the opposite of what I meant. STAGING is disabled in syzbot and FBDEV is enabled. regards, dan carpenter
On Thu, 27 Jan 2022 at 07:30, Dan Carpenter <dan.carpenter@oracle.com> wrote: > > On Wed, Jan 26, 2022 at 11:31:02PM +0100, Daniel Vetter wrote: > > dOn Wed, Jan 26, 2022 at 3:46 PM Dan Carpenter <dan.carpenter@oracle.com> wrote: > > > > > > The other advantage of staging is the I don't think syzbot enables it. > > > I guess it's easier to persuade Dmitry to ignore STAGING than it was to > > > get him to disable FBDEV. :P > > > > > > The memory corruption in fbdev was a real headache for everyone because > > > the stack traces ended up all over the kernel. > > > > Uh Dmitry disabled all of FBDEV? > > No that's the opposite of what I meant. STAGING is disabled in syzbot > and FBDEV is enabled. Is there still any problem with syzbot config? syzbot configs are stored here: https://github.com/google/syzkaller/tree/master/dashboard/config/linux
On Thu, 27 Jan 2022 at 12:11, Daniel Vetter <daniel@ffwll.ch> wrote: > > On Thu, Jan 27, 2022 at 11:32:58AM +0100, Dmitry Vyukov wrote: > > On Thu, 27 Jan 2022 at 07:30, Dan Carpenter <dan.carpenter@oracle.com> wrote: > > > > > > On Wed, Jan 26, 2022 at 11:31:02PM +0100, Daniel Vetter wrote: > > > > dOn Wed, Jan 26, 2022 at 3:46 PM Dan Carpenter <dan.carpenter@oracle.com> wrote: > > > > > > > > > > The other advantage of staging is the I don't think syzbot enables it. > > > > > I guess it's easier to persuade Dmitry to ignore STAGING than it was to > > > > > get him to disable FBDEV. :P > > > > > > > > > > The memory corruption in fbdev was a real headache for everyone because > > > > > the stack traces ended up all over the kernel. > > > > > > > > Uh Dmitry disabled all of FBDEV? > > > > > > No that's the opposite of what I meant. STAGING is disabled in syzbot > > > and FBDEV is enabled. > > > > Is there still any problem with syzbot config? > > syzbot configs are stored here: > > https://github.com/google/syzkaller/tree/master/dashboard/config/linux > > CONFIG_FB and CONFIG_FRAMEBUFFER_CONSOLE are set, which are the things I > care about. The one exception is upstream-kcsan.config, which doesn't have > fbcon enabled. > > Also looking through your fbdev drivers, really the only ones you want to > ever enable are: > CONFIG_FB_VGA16=y > CONFIG_FB_VESA=y > CONFIG_FB_VIRTUAL=y > > The following isn't enabled, but I guess if you don't have EFI doesn't > make sense, otherwise you really want it: > CONFIG_FB_EFI=y > > The below are enabled in some configs and should be ditched > CONFIG_FB_SIMPLE=y (use CONFIG_DRM_SIMPLEDRM instead, at least on kernels that have it) > CONFIG_FB_I740=y (you don't have this hw or I'm blown away, this last shipped 20 years ago) > CONFIG_FB_UDL=y (use CONFIG_DRM_UDL instead) > CONFIG_FB_UVESA=y (does modesets by calling into a userspace helper to run x86 vbios code, just don't) > CONFIG_FB_SMSCUFX=y (if you really have these then someone should port this to drm asap) > CONFIG_FB_CIRRUS=y (use CONFIG_DRM_CIRRUS_QEMU instead since I'm pretty sure you don't have a real cirrus pci card) > > Also note that the simpledrm driver will eat all the firmware fbdev > drivers and unload them. So you need to run two configs to really cover > both sets of drivers in all cases. Thanks! I've sent PR to update these configs as you suggest: https://github.com/google/syzkaller/pull/2993
On 1/26/22 15:15, Javier Martinez Canillas wrote: > On 1/26/22 15:10, Andy Shevchenko wrote: >> On Wed, Jan 26, 2022 at 04:08:32PM +0200, Andy Shevchenko wrote: >>> On Wed, Jan 26, 2022 at 02:46:08PM +0100, Javier Martinez Canillas wrote: >>>> On 1/26/22 14:12, Andy Shevchenko wrote: >> >> ... >> >>>> I've just bought a SSD1306 (I2C) based one and will attempt to write a DRM >>>> driver using drivers/staging/fbtft/fb_ssd1306.c as a reference. >>> >>> You should take ssd1307fb.c instead. And basically create a MIPI based driver >>> for I2C. Then we won't go same road again for other similar devices. >> >> For the record it supports your device: >> >> static const struct i2c_device_id ssd1307fb_i2c_id[] = { >> { "ssd1305fb", 0 }, >> { "ssd1306fb", 0 }, >> { "ssd1307fb", 0 }, >> { "ssd1309fb", 0 }, >> >> > > Thanks a lot for the pointer. I was only looking at drivers/staging > and didn't check drivers/video. I'll try to convert that one then > once I get the display. > I got some time this weekend and was able to port the ssd1306 fbdev driver to DRM [0]. I'm not that familiar with the simple display pipe helpers, so there may be some wrong things there. But it does work and all the fbtests from https://git.kernel.org/pub/scm/linux/kernel/git/geert/fbtest.git pass. There are some hacks in the driver though. For example it exposes an XRGB8888 format even thought the OLED display is monochromatic and has 1 bit per pixel. The driver then goes and converts the XRGB8888 pixels first to grayscale and then to reverse mono. I took that idea from the repaper driver but that gives us the multiple copies that Geert was complaining about. Another hack is that I am just hardcoding the {width, height}_mm, but I don't know what DPI could be used for these panels nor how I could calculate the mm. Best regards, Javier [0]:
Hi Am 31.01.22 um 09:29 schrieb Javier Martinez Canillas: > On 1/26/22 15:15, Javier Martinez Canillas wrote: >> On 1/26/22 15:10, Andy Shevchenko wrote: >>> On Wed, Jan 26, 2022 at 04:08:32PM +0200, Andy Shevchenko wrote: >>>> On Wed, Jan 26, 2022 at 02:46:08PM +0100, Javier Martinez Canillas wrote: >>>>> On 1/26/22 14:12, Andy Shevchenko wrote: >>> >>> ... >>> >>>>> I've just bought a SSD1306 (I2C) based one and will attempt to write a DRM >>>>> driver using drivers/staging/fbtft/fb_ssd1306.c as a reference. >>>> >>>> You should take ssd1307fb.c instead. And basically create a MIPI based driver >>>> for I2C. Then we won't go same road again for other similar devices. >>> >>> For the record it supports your device: >>> >>> static const struct i2c_device_id ssd1307fb_i2c_id[] = { >>> { "ssd1305fb", 0 }, >>> { "ssd1306fb", 0 }, >>> { "ssd1307fb", 0 }, >>> { "ssd1309fb", 0 }, >>> >>> >> >> Thanks a lot for the pointer. I was only looking at drivers/staging >> and didn't check drivers/video. I'll try to convert that one then >> once I get the display. >> > > I got some time this weekend and was able to port the ssd1306 fbdev driver > to DRM [0]. I'm not that familiar with the simple display pipe helpers, so > there may be some wrong things there. But it does work and all the fbtests > from https://git.kernel.org/pub/scm/linux/kernel/git/geert/fbtest.git pass. Awesome! > > There are some hacks in the driver though. For example it exposes an XRGB8888 > format even thought the OLED display is monochromatic and has 1 bit per pixel. > > The driver then goes and converts the XRGB8888 pixels first to grayscale and > then to reverse mono. I took that idea from the repaper driver but that gives > us the multiple copies that Geert was complaining about. This requires to update the console code for 1-bit BW output. The fbcon side already supports this AFAIK. DRM's fbdev needs a few more branches and something like a DRM_FORMAT_C1 fourcc. The XRGB8888 is really a userspace requirement that is imposed by modern desktops. If DRM's console has been updated, you could leave it out entirely. I could imagine that some simple userspace, such as Weston, comes with support for palette formats and BW. Or there could be an entirely separate program that puts graphics onto these displays. Best regards Thomas > > Another hack is that I am just hardcoding the {width, height}_mm, but I don't > know what DPI could be used for these panels nor how I could calculate the mm. > > Best regards, > Javier > > [0]: > From 5ec4b468b66022d4c48ae6bec8a68926a01a6785 Mon Sep 17 00:00:00 2001 > From: Javier Martinez Canillas <javierm@redhat.com> > Date: Sun, 30 Jan 2022 12:16:34 +0100 > Subject: [RFC] drm/tiny: Add driver for Solomon SSD130X OLED displays > > Add a DRM driver for SSD1305, SSD1306, SSD1307 and SSD1309 Solomon OLED > controllers that can be programmed via an I2C interface. This is a port > of the ssd1307fb driver that already supports these devices. > > A Device Tree binding is not added because the DRM driver is compatible > with the existing binding for the ssd1307fb driver. > > Signed-off-by: Javier Martinez Canillas <javierm@redhat.com> > --- > MAINTAINERS | 7 + > drivers/gpu/drm/tiny/Kconfig | 12 + > drivers/gpu/drm/tiny/Makefile | 1 + > drivers/gpu/drm/tiny/ssd130x.c | 944 +++++++++++++++++++++++++++++++++ > 4 files changed, 964 insertions(+) > create mode 100644 drivers/gpu/drm/tiny/ssd130x.c > > diff --git a/MAINTAINERS b/MAINTAINERS > index d03ad8da1f36..87334676ce07 100644 > --- a/MAINTAINERS > +++ b/MAINTAINERS > @@ -6102,6 +6102,13 @@ T: git git://anongit.freedesktop.org/drm/drm-misc > F: Documentation/devicetree/bindings/display/repaper.txt > F: drivers/gpu/drm/tiny/repaper.c > > +DRM DRIVER FOR SOLOMON SSD130X DISPLAYS > +M: Javier Martinez Canillas <javierm@redhat.com> > +S: Maintained > +T: git git://anongit.freedesktop.org/drm/drm-misc > +F: Documentation/devicetree/bindings/display/solomon,ssd1307fb.yaml > +F: drivers/gpu/drm/tiny/ssd130x.c > + > DRM DRIVER FOR QEMU'S CIRRUS DEVICE > M: Dave Airlie <airlied@redhat.com> > M: Gerd Hoffmann <kraxel@redhat.com> > diff --git a/drivers/gpu/drm/tiny/Kconfig b/drivers/gpu/drm/tiny/Kconfig > index 712e0004e96e..358ceb7354f5 100644 > --- a/drivers/gpu/drm/tiny/Kconfig > +++ b/drivers/gpu/drm/tiny/Kconfig > @@ -157,6 +157,18 @@ config TINYDRM_REPAPER > > If M is selected the module will be called repaper. > > +config TINYDRM_SSD130X > + tristate "DRM support for Solomon SSD130X OLED displays" > + depends on DRM && OF && I2C > + select DRM_KMS_HELPER > + select DRM_GEM_SHMEM_HELPER > + select BACKLIGHT_CLASS_DEVICE > + help > + DRM driver for the SSD1305, SSD1306, SSD1307 and SSD1309 Solomon > + OLED controllers that can be programmed via an I2C interface. > + > + If M is selected the module will be called ssd130x. > + > config TINYDRM_ST7586 > tristate "DRM support for Sitronix ST7586 display panels" > depends on DRM && SPI > diff --git a/drivers/gpu/drm/tiny/Makefile b/drivers/gpu/drm/tiny/Makefile > index 5d5505d40e7b..93a1d70155f0 100644 > --- a/drivers/gpu/drm/tiny/Makefile > +++ b/drivers/gpu/drm/tiny/Makefile > @@ -12,5 +12,6 @@ obj-$(CONFIG_TINYDRM_ILI9341) += ili9341.o > obj-$(CONFIG_TINYDRM_ILI9486) += ili9486.o > obj-$(CONFIG_TINYDRM_MI0283QT) += mi0283qt.o > obj-$(CONFIG_TINYDRM_REPAPER) += repaper.o > +obj-$(CONFIG_TINYDRM_SSD130X) += ssd130x.o > obj-$(CONFIG_TINYDRM_ST7586) += st7586.o > obj-$(CONFIG_TINYDRM_ST7735R) += st7735r.o > diff --git a/drivers/gpu/drm/tiny/ssd130x.c b/drivers/gpu/drm/tiny/ssd130x.c > new file mode 100644 > index 000000000000..88d88caeb37d > --- /dev/null > +++ b/drivers/gpu/drm/tiny/ssd130x.c > @@ -0,0 +1,944 @@ > +// SPDX-License-Identifier: GPL-2.0-only > +/* > + * DRM driver for Solomon SSD130X OLED displays > + * > + * Copyright 2022 Red Hat Inc. > + * > + * Based on drivers/video/fbdev/ssd1307fb.c > + * Copyright 2012 Free Electrons > + * > + */ > + > +#include <linux/backlight.h> > +#include <linux/delay.h> > +#include <linux/gpio/consumer.h> > +#include <linux/i2c.h> > +#include <linux/module.h> > +#include <linux/property.h> > +#include <linux/pwm.h> > +#include <linux/regulator/consumer.h> > + > +#include <drm/drm_atomic_helper.h> > +#include <drm/drm_damage_helper.h> > +#include <drm/drm_drv.h> > +#include <drm/drm_fb_cma_helper.h> > +#include <drm/drm_fb_helper.h> > +#include <drm/drm_format_helper.h> > +#include <drm/drm_gem_atomic_helper.h> > +#include <drm/drm_gem_framebuffer_helper.h> > +#include <drm/drm_gem_shmem_helper.h> > +#include <drm/drm_managed.h> > +#include <drm/drm_modes.h> > +#include <drm/drm_rect.h> > +#include <drm/drm_probe_helper.h> > +#include <drm/drm_simple_kms_helper.h> > + > +#define DRIVER_NAME "ssd130x" > +#define DRIVER_DESC "DRM driver for Solomon SSD130X OLED displays" > +#define DRIVER_DATE "20220130" > +#define DRIVER_MAJOR 1 > +#define DRIVER_MINOR 0 > + > +#define SSD130X_DATA 0x40 > +#define SSD130X_COMMAND 0x80 > + > +#define SSD130X_SET_ADDRESS_MODE 0x20 > +#define SSD130X_SET_ADDRESS_MODE_HORIZONTAL (0x00) > +#define SSD130X_SET_ADDRESS_MODE_VERTICAL (0x01) > +#define SSD130X_SET_ADDRESS_MODE_PAGE (0x02) > +#define SSD130X_SET_COL_RANGE 0x21 > +#define SSD130X_SET_PAGE_RANGE 0x22 > +#define SSD130X_CONTRAST 0x81 > +#define SSD130X_SET_LOOKUP_TABLE 0x91 > +#define SSD130X_CHARGE_PUMP 0x8d > +#define SSD130X_SEG_REMAP_ON 0xa1 > +#define SSD130X_DISPLAY_OFF 0xae > +#define SSD130X_SET_MULTIPLEX_RATIO 0xa8 > +#define SSD130X_DISPLAY_ON 0xaf > +#define SSD130X_START_PAGE_ADDRESS 0xb0 > +#define SSD130X_SET_DISPLAY_OFFSET 0xd3 > +#define SSD130X_SET_CLOCK_FREQ 0xd5 > +#define SSD130X_SET_AREA_COLOR_MODE 0xd8 > +#define SSD130X_SET_PRECHARGE_PERIOD 0xd9 > +#define SSD130X_SET_COM_PINS_CONFIG 0xda > +#define SSD130X_SET_VCOMH 0xdb > + > +#define MAX_CONTRAST 255 > + > +struct ssd130x_deviceinfo { > + u32 default_vcomh; > + u32 default_dclk_div; > + u32 default_dclk_frq; > + int need_pwm; > + int need_chargepump; > +}; > + > +struct ssd130x_device { > + struct drm_device drm; > + struct drm_simple_display_pipe pipe; > + struct drm_display_mode mode; > + struct drm_connector connector; > + struct i2c_client *client; > + > + const struct ssd130x_deviceinfo *device_info; > + > + unsigned area_color_enable : 1; > + unsigned com_invdir : 1; > + unsigned com_lrremap : 1; > + unsigned com_seq : 1; > + unsigned lookup_table_set : 1; > + unsigned low_power : 1; > + unsigned seg_remap : 1; > + u32 com_offset; > + u32 contrast; > + u32 dclk_div; > + u32 dclk_frq; > + u32 height; > + u8 lookup_table[4]; > + u32 page_offset; > + u32 col_offset; > + u32 prechargep1; > + u32 prechargep2; > + > + struct backlight_device *bl_dev; > + struct pwm_device *pwm; > + struct gpio_desc *reset; > + struct regulator *vbat_reg; > + u32 vcomh; > + u32 width; > + /* Cached address ranges */ > + u8 col_start; > + u8 col_end; > + u8 page_start; > + u8 page_end; > +}; > + > +struct ssd130x_array { > + u8 type; > + u8 data[]; > +}; > + > +static inline struct ssd130x_device *drm_to_ssd130x(struct drm_device *drm) > +{ > + return container_of(drm, struct ssd130x_device, drm); > +} > + > +static struct ssd130x_array *ssd130x_alloc_array(u32 len, u8 type) > +{ > + struct ssd130x_array *array; > + > + array = kzalloc(sizeof(struct ssd130x_array) + len, GFP_KERNEL); > + if (!array) > + return NULL; > + > + array->type = type; > + > + return array; > +} > + > +static int ssd130x_write_array(struct i2c_client *client, > + struct ssd130x_array *array, u32 len) > +{ > + int ret; > + > + len += sizeof(struct ssd130x_array); > + > + ret = i2c_master_send(client, (u8 *)array, len); > + if (ret != len) { > + dev_err(&client->dev, "Couldn't send I2C command.\n"); > + return ret; > + } > + > + return 0; > +} > + > +static inline int ssd130x_write_cmd(struct i2c_client *client, u8 cmd) > +{ > + struct ssd130x_array *array; > + int ret; > + > + array = ssd130x_alloc_array(1, SSD130X_COMMAND); > + if (!array) > + return -ENOMEM; > + > + array->data[0] = cmd; > + > + ret = ssd130x_write_array(client, array, 1); > + kfree(array); > + > + return ret; > +} > + > +static int ssd130x_set_col_range(struct ssd130x_device *ssd130x, > + u8 col_start, u8 cols) > +{ > + u8 col_end = col_start + cols - 1; > + int ret; > + > + if (col_start == ssd130x->col_start && col_end == ssd130x->col_end) > + return 0; > + > + ret = ssd130x_write_cmd(ssd130x->client, SSD130X_SET_COL_RANGE); > + if (ret < 0) > + return ret; > + > + ret = ssd130x_write_cmd(ssd130x->client, col_start); > + if (ret < 0) > + return ret; > + > + ret = ssd130x_write_cmd(ssd130x->client, col_end); > + if (ret < 0) > + return ret; > + > + ssd130x->col_start = col_start; > + ssd130x->col_end = col_end; > + return 0; > +} > + > +static int ssd130x_set_page_range(struct ssd130x_device *ssd130x, > + u8 page_start, u8 pages) > +{ > + u8 page_end = page_start + pages - 1; > + int ret; > + > + if (page_start == ssd130x->page_start && page_end == ssd130x->page_end) > + return 0; > + > + ret = ssd130x_write_cmd(ssd130x->client, SSD130X_SET_PAGE_RANGE); > + if (ret < 0) > + return ret; > + > + ret = ssd130x_write_cmd(ssd130x->client, page_start); > + if (ret < 0) > + return ret; > + > + ret = ssd130x_write_cmd(ssd130x->client, page_end); > + if (ret < 0) > + return ret; > + > + ssd130x->page_start = page_start; > + ssd130x->page_end = page_end; > + return 0; > +} > + > +static int ssd130x_update_display(struct ssd130x_device *ssd130x, u8 *buf, > + u32 width, u32 height) > +{ > + struct ssd130x_array *array; > + unsigned int line_length = DIV_ROUND_UP(width, 8); > + unsigned int pages = DIV_ROUND_UP(height, 8); > + u32 array_idx = 0; > + int ret, i, j, k; > + > + array = ssd130x_alloc_array(width * pages, SSD130X_DATA); > + if (!array) > + return -ENOMEM; > + > + /* > + * The screen is divided in pages, each having a height of 8 > + * pixels, and the width of the screen. When sending a byte of > + * data to the controller, it gives the 8 bits for the current > + * column. I.e, the first byte are the 8 bits of the first > + * column, then the 8 bits for the second column, etc. > + * > + * > + * Representation of the screen, assuming it is 5 bits > + * wide. Each letter-number combination is a bit that controls > + * one pixel. > + * > + * A0 A1 A2 A3 A4 > + * B0 B1 B2 B3 B4 > + * C0 C1 C2 C3 C4 > + * D0 D1 D2 D3 D4 > + * E0 E1 E2 E3 E4 > + * F0 F1 F2 F3 F4 > + * G0 G1 G2 G3 G4 > + * H0 H1 H2 H3 H4 > + * > + * If you want to update this screen, you need to send 5 bytes: > + * (1) A0 B0 C0 D0 E0 F0 G0 H0 > + * (2) A1 B1 C1 D1 E1 F1 G1 H1 > + * (3) A2 B2 C2 D2 E2 F2 G2 H2 > + * (4) A3 B3 C3 D3 E3 F3 G3 H3 > + * (5) A4 B4 C4 D4 E4 F4 G4 H4 > + */ > + > + ret = ssd130x_set_col_range(ssd130x, ssd130x->col_offset, width); > + if (ret < 0) > + goto out_free; > + > + ret = ssd130x_set_page_range(ssd130x, ssd130x->page_offset / 8, pages); > + if (ret < 0) > + goto out_free; > + > + for (i = 0; i < pages; i++) { > + int m = 8; > + > + /* Last page may be partial */ > + if (8 * (i + 1) > ssd130x->height) > + m = ssd130x->height % 8; > + for (j = 0; j < width; j++) { > + u8 data = 0; > + > + for (k = 0; k < m; k++) { > + u8 byte = buf[(8 * i + k) * line_length + > + j / 8]; > + u8 bit = (byte >> (j % 8)) & 1; > + > + data |= bit << k; > + } > + array->data[array_idx++] = data; > + } > + } > + > + ret = ssd130x_write_array(ssd130x->client, array, width * pages); > + > +out_free: > + kfree(array); > + return ret; > +} > + > +static void ssd130x_gray8_to_mono_reversed(u8 *buf, u32 width, u32 height) > +{ > + u8 *gray8 = buf, *mono = buf; > + int y, xb, i; > + > + for (y = 0; y < height; y++) > + for (xb = 0; xb < width / 8; xb++) { > + u8 byte = 0x00; > + > + for (i = 0; i < 8; i++) { > + int x = xb * 8 + i; > + > + byte >>= 1; > + if (gray8[y * width + x] >> 7) > + byte |= BIT(7); > + } > + *mono++ = byte; > + } > +} > + > +static int ssd130x_fb_blit_rect(struct drm_framebuffer *fb, const struct dma_buf_map *map, > + struct drm_rect *rect) > +{ > + struct ssd130x_device *ssd130x = drm_to_ssd130x(fb->dev); > + void *vmap = map->vaddr; /* TODO: Use mapping abstraction properly */ > + int idx, ret = 0; > + u8 *buf = NULL; > + > + if (!drm_dev_enter(fb->dev, &idx)) > + return -ENODEV; > + > + buf = kmalloc_array(fb->width, fb->height, GFP_KERNEL); > + if (!buf) { > + ret = -ENOMEM; > + goto out_exit; > + } > + > + drm_fb_xrgb8888_to_gray8(buf, 0, vmap, fb, rect); > + > + ssd130x_gray8_to_mono_reversed(buf, fb->width, fb->height); > + > + ssd130x_update_display(ssd130x, buf, fb->width, fb->height); > + > + kfree(buf); > +out_exit: > + drm_dev_exit(idx); > + > + return ret; > +} > + > +static void ssd130x_display_pipe_enable(struct drm_simple_display_pipe *pipe, > + struct drm_crtc_state *crtc_state, > + struct drm_plane_state *plane_state) > +{ > + struct ssd130x_device *ssd130x = drm_to_ssd130x(pipe->crtc.dev); > + int idx; > + > + if (!drm_dev_enter(pipe->crtc.dev, &idx)) > + return; > + > + backlight_enable(ssd130x->bl_dev); > + > + ssd130x_write_cmd(ssd130x->client, SSD130X_DISPLAY_ON); > +} > + > +static void ssd130x_display_pipe_disable(struct drm_simple_display_pipe *pipe) > +{ > + struct ssd130x_device *ssd130x = drm_to_ssd130x(pipe->crtc.dev); > + > + ssd130x_write_cmd(ssd130x->client, SSD130X_DISPLAY_OFF); > + > + backlight_disable(ssd130x->bl_dev); > +} > + > +static void ssd130x_display_pipe_update(struct drm_simple_display_pipe *pipe, > + struct drm_plane_state *old_plane_state) > +{ > + struct drm_plane_state *state = pipe->plane.state; > + struct drm_shadow_plane_state *shadow_plane_state = to_drm_shadow_plane_state(state); > + struct drm_rect rect; > + > + if (!pipe->crtc.state->active) > + return; > + > + if (drm_atomic_helper_damage_merged(old_plane_state, state, &rect)) > + ssd130x_fb_blit_rect(state->fb, &shadow_plane_state->data[0], &rect); > +} > + > +static const struct drm_simple_display_pipe_funcs ssd130x_pipe_funcs = { > + .enable = ssd130x_display_pipe_enable, > + .disable = ssd130x_display_pipe_disable, > + .update = ssd130x_display_pipe_update, > + DRM_GEM_SIMPLE_DISPLAY_PIPE_SHADOW_PLANE_FUNCS, > +}; > + > +static int ssd130x_connector_get_modes(struct drm_connector *connector) > +{ > + struct ssd130x_device *ssd130x = drm_to_ssd130x(connector->dev); > + struct drm_display_mode *mode; > + > + mode = drm_mode_duplicate(connector->dev, &ssd130x->mode); > + if (!mode) { > + DRM_ERROR("Failed to duplicate mode\n"); > + return 0; > + } > + > + connector->display_info.width_mm = mode->width_mm; > + connector->display_info.height_mm = mode->height_mm; > + connector->display_info.bpc = 32; > + > + drm_mode_set_name(mode); > + mode->type |= DRM_MODE_TYPE_PREFERRED; > + drm_mode_probed_add(connector, mode); > + > + return 1; > +} > + > +static const struct drm_connector_helper_funcs ssd130x_connector_helper_funcs = { > + .get_modes = ssd130x_connector_get_modes, > +}; > + > +static const struct drm_connector_funcs ssd130x_connector_funcs = { > + .reset = drm_atomic_helper_connector_reset, > + .fill_modes = drm_helper_probe_single_connector_modes, > + .destroy = drm_connector_cleanup, > + .atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state, > + .atomic_destroy_state = drm_atomic_helper_connector_destroy_state, > +}; > + > +static const struct drm_mode_config_funcs ssd130x_mode_config_funcs = { > + .fb_create = drm_gem_fb_create_with_dirty, > + .atomic_check = drm_atomic_helper_check, > + .atomic_commit = drm_atomic_helper_commit, > +}; > + > +static const uint32_t ssd130x_formats[] = { > + DRM_FORMAT_XRGB8888, > +}; > + > +DEFINE_DRM_GEM_FOPS(ssd130x_fops); > + > +static const struct drm_driver ssd130x_drm_driver = { > + DRM_GEM_SHMEM_DRIVER_OPS, > + .name = DRIVER_NAME, > + .desc = DRIVER_DESC, > + .date = DRIVER_DATE, > + .major = DRIVER_MAJOR, > + .minor = DRIVER_MINOR, > + .driver_features = DRIVER_ATOMIC | DRIVER_GEM | DRIVER_MODESET, > + .fops = &ssd130x_fops, > +}; > + > +static int ssd130x_pwm_enable(struct ssd130x_device *ssd130x) > +{ > + struct pwm_state pwmstate; > + > + ssd130x->pwm = pwm_get(&ssd130x->client->dev, NULL); > + if (IS_ERR(ssd130x->pwm)) { > + dev_err(&ssd130x->client->dev, "Could not get PWM from device tree!\n"); > + return PTR_ERR(ssd130x->pwm); > + } > + > + pwm_init_state(ssd130x->pwm, &pwmstate); > + pwm_set_relative_duty_cycle(&pwmstate, 50, 100); > + pwm_apply_state(ssd130x->pwm, &pwmstate); > + > + /* Enable the PWM */ > + pwm_enable(ssd130x->pwm); > + > + dev_dbg(&ssd130x->client->dev, "Using PWM%d with a %lluns period.\n", > + ssd130x->pwm->pwm, pwm_get_period(ssd130x->pwm)); > + > + return 0; > +} > + > +static int ssd130x_init(struct ssd130x_device *ssd130x) > +{ > + u32 precharge, dclk, com_invdir, compins; > + int ret; > + > + /* Set initial contrast */ > + ret = ssd130x_write_cmd(ssd130x->client, SSD130X_CONTRAST); > + if (ret < 0) > + return ret; > + > + ret = ssd130x_write_cmd(ssd130x->client, ssd130x->contrast); > + if (ret < 0) > + return ret; > + > + /* Set segment re-map */ > + if (ssd130x->seg_remap) { > + ret = ssd130x_write_cmd(ssd130x->client, SSD130X_SEG_REMAP_ON); > + if (ret < 0) > + return ret; > + } > + > + /* Set COM direction */ > + com_invdir = 0xc0 | ssd130x->com_invdir << 3; > + ret = ssd130x_write_cmd(ssd130x->client, com_invdir); > + if (ret < 0) > + return ret; > + > + /* Set multiplex ratio value */ > + ret = ssd130x_write_cmd(ssd130x->client, SSD130X_SET_MULTIPLEX_RATIO); > + if (ret < 0) > + return ret; > + > + ret = ssd130x_write_cmd(ssd130x->client, ssd130x->height - 1); > + if (ret < 0) > + return ret; > + > + /* set display offset value */ > + ret = ssd130x_write_cmd(ssd130x->client, SSD130X_SET_DISPLAY_OFFSET); > + if (ret < 0) > + return ret; > + > + ret = ssd130x_write_cmd(ssd130x->client, ssd130x->com_offset); > + if (ret < 0) > + return ret; > + > + /* Set clock frequency */ > + ret = ssd130x_write_cmd(ssd130x->client, SSD130X_SET_CLOCK_FREQ); > + if (ret < 0) > + return ret; > + > + dclk = ((ssd130x->dclk_div - 1) & 0xf) | (ssd130x->dclk_frq & 0xf) << 4; > + ret = ssd130x_write_cmd(ssd130x->client, dclk); > + if (ret < 0) > + return ret; > + > + /* Set Area Color Mode ON/OFF & Low Power Display Mode */ > + if (ssd130x->area_color_enable || ssd130x->low_power) { > + u32 mode; > + > + ret = ssd130x_write_cmd(ssd130x->client, > + SSD130X_SET_AREA_COLOR_MODE); > + if (ret < 0) > + return ret; > + > + mode = (ssd130x->area_color_enable ? 0x30 : 0) | > + (ssd130x->low_power ? 5 : 0); > + ret = ssd130x_write_cmd(ssd130x->client, mode); > + if (ret < 0) > + return ret; > + } > + > + /* Set precharge period in number of ticks from the internal clock */ > + ret = ssd130x_write_cmd(ssd130x->client, SSD130X_SET_PRECHARGE_PERIOD); > + if (ret < 0) > + return ret; > + > + precharge = (ssd130x->prechargep1 & 0xf) | (ssd130x->prechargep2 & 0xf) << 4; > + ret = ssd130x_write_cmd(ssd130x->client, precharge); > + if (ret < 0) > + return ret; > + > + /* Set COM pins configuration */ > + ret = ssd130x_write_cmd(ssd130x->client, SSD130X_SET_COM_PINS_CONFIG); > + if (ret < 0) > + return ret; > + > + compins = 0x02 | !ssd130x->com_seq << 4 | ssd130x->com_lrremap << 5; > + ret = ssd130x_write_cmd(ssd130x->client, compins); > + if (ret < 0) > + return ret; > + > + /* Set VCOMH */ > + ret = ssd130x_write_cmd(ssd130x->client, SSD130X_SET_VCOMH); > + if (ret < 0) > + return ret; > + > + ret = ssd130x_write_cmd(ssd130x->client, ssd130x->vcomh); > + if (ret < 0) > + return ret; > + > + /* Turn on the DC-DC Charge Pump */ > + ret = ssd130x_write_cmd(ssd130x->client, SSD130X_CHARGE_PUMP); > + if (ret < 0) > + return ret; > + > + ret = ssd130x_write_cmd(ssd130x->client, > + BIT(4) | (ssd130x->device_info->need_chargepump ? BIT(2) : 0)); > + if (ret < 0) > + return ret; > + > + /* Set lookup table */ > + if (ssd130x->lookup_table_set) { > + int i; > + > + ret = ssd130x_write_cmd(ssd130x->client, > + SSD130X_SET_LOOKUP_TABLE); > + if (ret < 0) > + return ret; > + > + for (i = 0; i < ARRAY_SIZE(ssd130x->lookup_table); ++i) { > + u8 val = ssd130x->lookup_table[i]; > + > + if (val < 31 || val > 63) > + dev_warn(&ssd130x->client->dev, > + "lookup table index %d value out of range 31 <= %d <= 63\n", > + i, val); > + ret = ssd130x_write_cmd(ssd130x->client, val); > + if (ret < 0) > + return ret; > + } > + } > + > + /* Switch to horizontal addressing mode */ > + ret = ssd130x_write_cmd(ssd130x->client, SSD130X_SET_ADDRESS_MODE); > + if (ret < 0) > + return ret; > + > + ret = ssd130x_write_cmd(ssd130x->client, > + SSD130X_SET_ADDRESS_MODE_HORIZONTAL); > + if (ret < 0) > + return ret; > + > + /* Turn on the display */ > + ret = ssd130x_write_cmd(ssd130x->client, SSD130X_DISPLAY_ON); > + if (ret < 0) > + return ret; > + > + return 0; > +} > + > +static int ssd130x_update_bl(struct backlight_device *bdev) > +{ > + struct ssd130x_device *ssd130x = bl_get_data(bdev); > + int brightness = bdev->props.brightness; > + int ret; > + > + ssd130x->contrast = brightness; > + > + ret = ssd130x_write_cmd(ssd130x->client, SSD130X_CONTRAST); > + if (ret < 0) > + return ret; > + > + ret = ssd130x_write_cmd(ssd130x->client, ssd130x->contrast); > + if (ret < 0) > + return ret; > + > + return 0; > +} > + > +static int ssd130x_get_brightness(struct backlight_device *bdev) > +{ > + struct ssd130x_device *ssd130x = bl_get_data(bdev); > + > + return ssd130x->contrast; > +} > + > +static const struct backlight_ops ssd130xfb_bl_ops = { > + .update_status = ssd130x_update_bl, > + .get_brightness = ssd130x_get_brightness, > +}; > + > +static void ssd130x_reset(struct ssd130x_device *ssd130x) > +{ > + /* Reset the screen */ > + gpiod_set_value_cansleep(ssd130x->reset, 1); > + udelay(4); > + gpiod_set_value_cansleep(ssd130x->reset, 0); > + udelay(4); > +} > + > +static void ssd130x_parse_properties(struct ssd130x_device *ssd130x) > +{ > + struct device *dev = &ssd130x->client->dev; > + > + if (device_property_read_u32(dev, "solomon,width", &ssd130x->width)) > + ssd130x->width = 96; > + > + if (device_property_read_u32(dev, "solomon,height", &ssd130x->height)) > + ssd130x->height = 16; > + > + if (device_property_read_u32(dev, "solomon,page-offset", &ssd130x->page_offset)) > + ssd130x->page_offset = 1; > + > + if (device_property_read_u32(dev, "solomon,col-offset", &ssd130x->col_offset)) > + ssd130x->col_offset = 0; > + > + if (device_property_read_u32(dev, "solomon,com-offset", &ssd130x->com_offset)) > + ssd130x->com_offset = 0; > + > + if (device_property_read_u32(dev, "solomon,prechargep1", &ssd130x->prechargep1)) > + ssd130x->prechargep1 = 2; > + > + if (device_property_read_u32(dev, "solomon,prechargep2", &ssd130x->prechargep2)) > + ssd130x->prechargep2 = 2; > + > + if (!device_property_read_u8_array(dev, "solomon,lookup-table", > + ssd130x->lookup_table, > + ARRAY_SIZE(ssd130x->lookup_table))) > + ssd130x->lookup_table_set = 1; > + > + ssd130x->seg_remap = !device_property_read_bool(dev, "solomon,segment-no-remap"); > + ssd130x->com_seq = device_property_read_bool(dev, "solomon,com-seq"); > + ssd130x->com_lrremap = device_property_read_bool(dev, "solomon,com-lrremap"); > + ssd130x->com_invdir = device_property_read_bool(dev, "solomon,com-invdir"); > + ssd130x->area_color_enable = > + device_property_read_bool(dev, "solomon,area-color-enable"); > + ssd130x->low_power = device_property_read_bool(dev, "solomon,low-power"); > + > + ssd130x->contrast = 127; > + ssd130x->vcomh = ssd130x->device_info->default_vcomh; > + > + /* Setup display timing */ > + if (device_property_read_u32(dev, "solomon,dclk-div", &ssd130x->dclk_div)) > + ssd130x->dclk_div = ssd130x->device_info->default_dclk_div; > + if (device_property_read_u32(dev, "solomon,dclk-frq", &ssd130x->dclk_frq)) > + ssd130x->dclk_frq = ssd130x->device_info->default_dclk_frq; > +} > + > +static void ssd130x_set_mode(struct ssd130x_device *ssd130x) > +{ > + struct drm_display_mode *mode = &ssd130x->mode; > + struct drm_device *drm = &ssd130x->drm; > + > + mode->type = DRM_MODE_TYPE_DRIVER; > + mode->clock = 1; > + mode->hdisplay = mode->htotal = ssd130x->width; > + mode->hsync_start = mode->hsync_end = ssd130x->width; > + mode->vdisplay = mode->vtotal = ssd130x->height; > + mode->vsync_start = mode->vsync_end = ssd130x->height; > + mode->width_mm = 27; > + mode->height_mm = 27; > + > + drm->mode_config.min_width = ssd130x->width; > + drm->mode_config.max_width = ssd130x->width; > + drm->mode_config.min_height = ssd130x->height; > + drm->mode_config.max_height = ssd130x->height; > + drm->mode_config.preferred_depth = 32; > + drm->mode_config.funcs = &ssd130x_mode_config_funcs; > +} > + > +static int ssd130x_probe(struct i2c_client *client) > +{ > + struct device *dev = &client->dev; > + struct ssd130x_device *ssd130x; > + struct backlight_device *bl; > + struct drm_device *drm; > + char bl_name[12]; > + int ret; > + > + ssd130x = devm_drm_dev_alloc(dev, &ssd130x_drm_driver, > + struct ssd130x_device, drm); > + if (IS_ERR(ssd130x)) > + return PTR_ERR(ssd130x); > + > + drm = &ssd130x->drm; > + > + ret = drmm_mode_config_init(drm); > + if (ret) > + return ret; > + > + ssd130x->client = client; > + > + ssd130x->device_info = device_get_match_data(dev); > + > + ssd130x_parse_properties(ssd130x); > + > + ssd130x_set_mode(ssd130x); > + > + ssd130x->reset = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_LOW); > + if (IS_ERR(ssd130x->reset)) { > + dev_err(dev, "failed to get reset gpio: %ld\n", > + PTR_ERR(ssd130x->reset)); > + return PTR_ERR(ssd130x->reset); > + } > + > + ssd130x->vbat_reg = devm_regulator_get_optional(dev, "vbat"); > + if (IS_ERR(ssd130x->vbat_reg)) { > + ret = PTR_ERR(ssd130x->vbat_reg); > + if (ret == -ENODEV) { > + ssd130x->vbat_reg = NULL; > + } else { > + dev_err(dev, "failed to get VBAT regulator: %d\n", ret); > + return ret; > + } > + } > + > + drm_connector_helper_add(&ssd130x->connector, &ssd130x_connector_helper_funcs); > + ret = drm_connector_init(drm, &ssd130x->connector, &ssd130x_connector_funcs, > + DRM_MODE_CONNECTOR_Unknown); > + if (ret) > + return ret; > + > + i2c_set_clientdata(client, ssd130x); > + > + if (ssd130x->reset) > + ssd130x_reset(ssd130x); > + > + if (ssd130x->vbat_reg) { > + ret = regulator_enable(ssd130x->vbat_reg); > + if (ret) { > + dev_err(dev, "failed to enable VBAT: %d\n", ret); > + return ret; > + } > + } > + > + ret = ssd130x_init(ssd130x); > + if (ret) > + goto regulator_disable; > + > + if (ssd130x->device_info->need_pwm) { > + ret = ssd130x_pwm_enable(ssd130x); > + if (ret) > + goto regulator_disable; > + } > + > + snprintf(bl_name, sizeof(bl_name), "ssd130x%d", drm->primary->index); > + bl = backlight_device_register(bl_name, dev, ssd130x, &ssd130xfb_bl_ops, > + NULL); > + if (IS_ERR(bl)) { > + ret = PTR_ERR(bl); > + dev_err(dev, "unable to register backlight device: %d\n", ret); > + goto pwm_disable; > + } > + > + bl->props.brightness = ssd130x->contrast; > + bl->props.max_brightness = MAX_CONTRAST; > + ssd130x->bl_dev = bl; > + > + ret = drm_simple_display_pipe_init(drm, &ssd130x->pipe, &ssd130x_pipe_funcs, > + ssd130x_formats, ARRAY_SIZE(ssd130x_formats), > + NULL, &ssd130x->connector); > + if (ret) > + goto pwm_disable; > + > + drm_plane_enable_fb_damage_clips(&ssd130x->pipe.plane); > + > + drm_mode_config_reset(drm); > + > + ret = drm_dev_register(drm, 0); > + if (ret) > + goto backlight_unregister; > + > + drm_fbdev_generic_setup(drm, 0); > + > + return 0; > + > +backlight_unregister: > + backlight_device_unregister(ssd130x->bl_dev); > +pwm_disable: > + if (ssd130x->device_info->need_pwm) { > + pwm_disable(ssd130x->pwm); > + pwm_put(ssd130x->pwm); > + } > +regulator_disable: > + if (ssd130x->vbat_reg) > + regulator_disable(ssd130x->vbat_reg); > + return ret; > +} > + > +static int ssd130x_remove(struct i2c_client *client) > +{ > + struct ssd130x_device *ssd130x = i2c_get_clientdata(client); > + > + drm_dev_unplug(&ssd130x->drm); > + > + ssd130x_write_cmd(ssd130x->client, SSD130X_DISPLAY_OFF); > + > + backlight_device_unregister(ssd130x->bl_dev); > + > + if (ssd130x->device_info->need_pwm) { > + pwm_disable(ssd130x->pwm); > + pwm_put(ssd130x->pwm); > + } > + if (ssd130x->vbat_reg) > + regulator_disable(ssd130x->vbat_reg); > + > + return 0; > +} > + > +static void ssd130x_shutdown(struct i2c_client *client) > +{ > + struct ssd130x_device *ssd130x = i2c_get_clientdata(client); > + > + drm_atomic_helper_shutdown(&ssd130x->drm); > +} > + > +static struct ssd130x_deviceinfo ssd130x_ssd1305_deviceinfo = { > + .default_vcomh = 0x34, > + .default_dclk_div = 1, > + .default_dclk_frq = 7, > +}; > + > +static struct ssd130x_deviceinfo ssd130x_ssd1306_deviceinfo = { > + .default_vcomh = 0x20, > + .default_dclk_div = 1, > + .default_dclk_frq = 8, > + .need_chargepump = 1, > +}; > + > +static struct ssd130x_deviceinfo ssd130x_ssd1307_deviceinfo = { > + .default_vcomh = 0x20, > + .default_dclk_div = 2, > + .default_dclk_frq = 12, > + .need_pwm = 1, > +}; > + > +static struct ssd130x_deviceinfo ssd130x_ssd1309_deviceinfo = { > + .default_vcomh = 0x34, > + .default_dclk_div = 1, > + .default_dclk_frq = 10, > +}; > + > +static const struct of_device_id ssd130x_of_match[] = { > + { > + .compatible = "solomon,ssd1305fb-i2c", > + .data = (void *)&ssd130x_ssd1305_deviceinfo, > + }, > + { > + .compatible = "solomon,ssd1306fb-i2c", > + .data = (void *)&ssd130x_ssd1306_deviceinfo, > + }, > + { > + .compatible = "solomon,ssd1307fb-i2c", > + .data = (void *)&ssd130x_ssd1307_deviceinfo, > + }, > + { > + .compatible = "solomon,ssd1309fb-i2c", > + .data = (void *)&ssd130x_ssd1309_deviceinfo, > + }, > + {}, > +}; > +MODULE_DEVICE_TABLE(of, ssd130x_of_match); > + > + > +static struct i2c_driver ssd130x_i2c_driver = { > + .driver = { > + .name = DRIVER_NAME, > + .of_match_table = ssd130x_of_match, > + }, > + .probe_new = ssd130x_probe, > + .remove = ssd130x_remove, > + .shutdown = ssd130x_shutdown, > +}; > + > +module_i2c_driver(ssd130x_i2c_driver); > + > +MODULE_DESCRIPTION(DRIVER_DESC); > +MODULE_AUTHOR("Javier Martinez Canillas <javierm@redhat.com>"); > +MODULE_LICENSE("GPL v2");
Hello Thomas, On 1/31/22 10:18, Thomas Zimmermann wrote: [snip] >> There are some hacks in the driver though. For example it exposes an XRGB8888 >> format even thought the OLED display is monochromatic and has 1 bit per pixel. >> >> The driver then goes and converts the XRGB8888 pixels first to grayscale and >> then to reverse mono. I took that idea from the repaper driver but that gives >> us the multiple copies that Geert was complaining about. > > This requires to update the console code for 1-bit BW output. The fbcon > side already supports this AFAIK. DRM's fbdev needs a few more branches > and something like a DRM_FORMAT_C1 fourcc. The XRGB8888 is really a > userspace requirement that is imposed by modern desktops. If DRM's > console has been updated, you could leave it out entirely. > > I could imagine that some simple userspace, such as Weston, comes with > support for palette formats and BW. Or there could be an entirely > separate program that puts graphics onto these displays. > Yes, I understand the rationale of why the repaper driver is doing that way but was just pointing out because Geert mentioned that is not efficient. Maybe in the meantime we can add a drm_fb_gray8_to_mono_reversed() helper to drivers/gpu/drm/drm_format_helper.c since there is more than one driver that does the same ? It's not a big issue for this device really since the I2C bus is slow anyways and the multiple copies are not a bottleneck AFAICT. I believe is worth to propose this driver as is and then try to optimize later. Another thing that's missing is a DRM_MODE_CONNECTOR_I2C, because I used for now a DRM_MODE_CONNECTOR_Unknown. Best regards,
Hi Am 31.01.22 um 11:18 schrieb Javier Martinez Canillas: > Hello Thomas, > > On 1/31/22 10:18, Thomas Zimmermann wrote: > > [snip] > >>> There are some hacks in the driver though. For example it exposes an XRGB8888 >>> format even thought the OLED display is monochromatic and has 1 bit per pixel. >>> >>> The driver then goes and converts the XRGB8888 pixels first to grayscale and >>> then to reverse mono. I took that idea from the repaper driver but that gives >>> us the multiple copies that Geert was complaining about. >> >> This requires to update the console code for 1-bit BW output. The fbcon >> side already supports this AFAIK. DRM's fbdev needs a few more branches >> and something like a DRM_FORMAT_C1 fourcc. The XRGB8888 is really a >> userspace requirement that is imposed by modern desktops. If DRM's >> console has been updated, you could leave it out entirely. >> >> I could imagine that some simple userspace, such as Weston, comes with >> support for palette formats and BW. Or there could be an entirely >> separate program that puts graphics onto these displays. >> > > Yes, I understand the rationale of why the repaper driver is doing that way > but was just pointing out because Geert mentioned that is not efficient. It's a fair point, I think. People are concerned about resource consumption on low-end devices. > > Maybe in the meantime we can add a drm_fb_gray8_to_mono_reversed() helper to > drivers/gpu/drm/drm_format_helper.c since there is more than one driver that > does the same ? Sure. > > It's not a big issue for this device really since the I2C bus is slow anyways > and the multiple copies are not a bottleneck AFAICT. > > I believe is worth to propose this driver as is and then try to optimize later. Absolutely. If you post a cleaned-up version of the patch, I'd take a look. > > Another thing that's missing is a DRM_MODE_CONNECTOR_I2C, because I used for > now a DRM_MODE_CONNECTOR_Unknown. That might have implications on userspace. Maybe ask around. (Not that we actually run userspace on the device). Best regards Thomas > > Best regards,
On Mon, Jan 31, 2022 at 09:29:33AM +0100, Javier Martinez Canillas wrote: > On 1/26/22 15:15, Javier Martinez Canillas wrote: > > On 1/26/22 15:10, Andy Shevchenko wrote: > >> On Wed, Jan 26, 2022 at 04:08:32PM +0200, Andy Shevchenko wrote: > >>> On Wed, Jan 26, 2022 at 02:46:08PM +0100, Javier Martinez Canillas wrote: > >>>> On 1/26/22 14:12, Andy Shevchenko wrote: > >> > >> ... > >> > >>>> I've just bought a SSD1306 (I2C) based one and will attempt to write a DRM > >>>> driver using drivers/staging/fbtft/fb_ssd1306.c as a reference. > >>> > >>> You should take ssd1307fb.c instead. And basically create a MIPI based driver > >>> for I2C. Then we won't go same road again for other similar devices. > >> > >> For the record it supports your device: > >> > >> static const struct i2c_device_id ssd1307fb_i2c_id[] = { > >> { "ssd1305fb", 0 }, > >> { "ssd1306fb", 0 }, > >> { "ssd1307fb", 0 }, > >> { "ssd1309fb", 0 }, > >> > >> > > > > Thanks a lot for the pointer. I was only looking at drivers/staging > > and didn't check drivers/video. I'll try to convert that one then > > once I get the display. > > > > I got some time this weekend and was able to port the ssd1306 fbdev driver > to DRM [0]. I'm not that familiar with the simple display pipe helpers, so > there may be some wrong things there. But it does work and all the fbtests > from https://git.kernel.org/pub/scm/linux/kernel/git/geert/fbtest.git pass. Thanks! Good news, everybody! > There are some hacks in the driver though. For example it exposes an XRGB8888 > format even thought the OLED display is monochromatic and has 1 bit per pixel. > > The driver then goes and converts the XRGB8888 pixels first to grayscale and > then to reverse mono. I took that idea from the repaper driver but that gives > us the multiple copies that Geert was complaining about. > > Another hack is that I am just hardcoding the {width, height}_mm, but I don't > know what DPI could be used for these panels nor how I could calculate the mm. I think the hacks is the first what should be eliminated, also see below. ... > +config TINYDRM_SSD130X > + tristate "DRM support for Solomon SSD130X OLED displays" > + depends on DRM && OF && I2C Please, make sure that it does NOT dependent on OF. ... > +obj-$(CONFIG_TINYDRM_SSD130X) += ssd130x.o I would keep the original name since we have I2C (fbdev) implementation, SPI and platform (fbtft), and now i2c (drm). I would like to avoid more confusion that we already have.
Hello Andy, Thanks a lot for your feedback. On 1/31/22 12:36, Andy Shevchenko wrote: [snip] >> >> Another hack is that I am just hardcoding the {width, height}_mm, but I don't >> know what DPI could be used for these panels nor how I could calculate the mm. > > I think the hacks is the first what should be eliminated, also see below. > Yes, agreed. But as we discussed with Thomas I'll post anyways since these could be addressed as a follow-up. > ... > >> +config TINYDRM_SSD130X >> + tristate "DRM support for Solomon SSD130X OLED displays" >> + depends on DRM && OF && I2C > > Please, make sure that it does NOT dependent on OF. > I actually added this dependency deliberative. It's true that the driver is using the device properties API and so there isn't anything from the properties parsing point of view that depends on OF. And the original driver didn't depend on OF. But the original driver also only would had worked with Device Trees since the of_device_id table is the only one that contains the device specific data info. The i2c_device_id table only listed the devices supported to match, but then it would only had worked with the default values that are set by the driver. So in practice it *does* depend on OF. I'll be happy to drop that dependency if you provide an acpi_device_id table to match. > ... > >> +obj-$(CONFIG_TINYDRM_SSD130X) += ssd130x.o > > I would keep the original name since we have I2C (fbdev) implementation, SPI > and platform (fbtft), and now i2c (drm). I would like to avoid more confusion > that we already have. > I see. That makes sense. Will I keep the original ssd1307 name then and not rename it to ssd130x (even though it would be more precise since supports a family of displays). Best regards,
On Mon, Jan 31, 2022 at 01:08:32PM +0100, Javier Martinez Canillas wrote: > On 1/31/22 12:36, Andy Shevchenko wrote: ... > >> +config TINYDRM_SSD130X > >> + tristate "DRM support for Solomon SSD130X OLED displays" > >> + depends on DRM && OF && I2C > > > > Please, make sure that it does NOT dependent on OF. > > > > I actually added this dependency deliberative. It's true that the driver is using > the device properties API and so there isn't anything from the properties parsing > point of view that depends on OF. And the original driver didn't depend on OF. > > But the original driver also only would had worked with Device Trees since the > of_device_id table is the only one that contains the device specific data info. > > The i2c_device_id table only listed the devices supported to match, but then it > would only had worked with the default values that are set by the driver. > > So in practice it *does* depend on OF. I'll be happy to drop that dependency if > you provide an acpi_device_id table to match. The code is deceptive and you become to a wrong conclusion. No, the driver does NOT depend on OF as a matter of fact. The tricky part is the PRP0001 ACPI PNP ID that allows to reuse it on ACPI-based platforms. That said, please drop OF dependency.
On Mon, Jan 31, 2022 at 03:23:13PM +0200, Andy Shevchenko wrote: > On Mon, Jan 31, 2022 at 01:08:32PM +0100, Javier Martinez Canillas wrote: > > On 1/31/22 12:36, Andy Shevchenko wrote: ... > > I actually added this dependency deliberative. It's true that the driver is using > > the device properties API and so there isn't anything from the properties parsing > > point of view that depends on OF. And the original driver didn't depend on OF. > > > > But the original driver also only would had worked with Device Trees since the > > of_device_id table is the only one that contains the device specific data info. > > > > The i2c_device_id table only listed the devices supported to match, but then it > > would only had worked with the default values that are set by the driver. > > > > So in practice it *does* depend on OF. I'll be happy to drop that dependency if > > you provide an acpi_device_id table to match. > > The code is deceptive and you become to a wrong conclusion. No, the driver > does NOT depend on OF as a matter of fact. The tricky part is the PRP0001 > ACPI PNP ID that allows to reuse it on ACPI-based platforms. > > That said, please drop OF dependency. Side note: 72915994e028 ("video: ssd1307fb: Make use of device properties")
On 1/31/22 14:23, Andy Shevchenko wrote: > On Mon, Jan 31, 2022 at 01:08:32PM +0100, Javier Martinez Canillas wrote: >> On 1/31/22 12:36, Andy Shevchenko wrote: > > ... > >>>> +config TINYDRM_SSD130X >>>> + tristate "DRM support for Solomon SSD130X OLED displays" >>>> + depends on DRM && OF && I2C >>> >>> Please, make sure that it does NOT dependent on OF. >>> >> >> I actually added this dependency deliberative. It's true that the driver is using >> the device properties API and so there isn't anything from the properties parsing >> point of view that depends on OF. And the original driver didn't depend on OF. >> >> But the original driver also only would had worked with Device Trees since the >> of_device_id table is the only one that contains the device specific data info. >> >> The i2c_device_id table only listed the devices supported to match, but then it >> would only had worked with the default values that are set by the driver. >> >> So in practice it *does* depend on OF. I'll be happy to drop that dependency if >> you provide an acpi_device_id table to match. > > The code is deceptive and you become to a wrong conclusion. No, the driver > does NOT depend on OF as a matter of fact. The tricky part is the PRP0001 > ACPI PNP ID that allows to reuse it on ACPI-based platforms. > Oh, I wasn't aware about PRP0001. I've read about it at: https://www.kernel.org/doc/Documentation/acpi/enumeration.txt > That said, please drop OF dependency. > Yes, got your point now and will drop the dep. Thanks for the explanation. Best regards,
On Mon, Jan 31, 2022 at 02:55:21PM +0100, Javier Martinez Canillas wrote: > On 1/31/22 14:23, Andy Shevchenko wrote: > > On Mon, Jan 31, 2022 at 01:08:32PM +0100, Javier Martinez Canillas wrote: ... > > The tricky part is the PRP0001 > > ACPI PNP ID that allows to reuse it on ACPI-based platforms. > > Oh, I wasn't aware about PRP0001. I've read about it at: > > https://www.kernel.org/doc/Documentation/acpi/enumeration.txt Yep! The idea is that new drivers for discrete (and sometimes even on-SoC) components should be platform-agnostic (means no strict OF / ACPI dependencies), so anybody can prototype devices on either of the platforms. As a matter of fact IIO subsystem is leading in this by cleaning up most of the drivers towards that goal. OF/ACPI explicit dependency makes sense when we 100+% sure that IP in question won't ever appear on the other type of platform (which I believe is very rare nowadays for most of the components).
Hi Thomas, On Tue, Feb 1, 2022 at 5:16 PM Thomas Zimmermann <tzimmermann@suse.de> wrote: > Am 31.01.22 um 11:18 schrieb Javier Martinez Canillas: > > Another thing that's missing is a DRM_MODE_CONNECTOR_I2C, because I used for > > now a DRM_MODE_CONNECTOR_Unknown. > > That might have implications on userspace. Maybe ask around. (Not that > we actually run userspace on the device). Looking at the list of connector types (and wondering if we're gonna need more when converting existing fbdev drivers to drm drivers), there seem to be two different families of connector types, for 1. transports between CRTC and display (e.g. VGA, DVID, HDMI), 2. transports between CPU and CRTC (e.g. SPI, possibly USB, and the proposed I2C)? Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds
On Tue, Feb 1, 2022 at 6:01 PM Geert Uytterhoeven <geert@linux-m68k.org> wrote: > > Hi Thomas, > > On Tue, Feb 1, 2022 at 5:16 PM Thomas Zimmermann <tzimmermann@suse.de> wrote: > > Am 31.01.22 um 11:18 schrieb Javier Martinez Canillas: > > > Another thing that's missing is a DRM_MODE_CONNECTOR_I2C, because I used for > > > now a DRM_MODE_CONNECTOR_Unknown. > > > > That might have implications on userspace. Maybe ask around. (Not that > > we actually run userspace on the device). > > Looking at the list of connector types (and wondering if we're gonna > need more when converting existing fbdev drivers to drm drivers), > there seem to be two different families of connector types, for > 1. transports between CRTC and display (e.g. VGA, DVID, HDMI), > 2. transports between CPU and CRTC (e.g. SPI, possibly USB, and > the proposed I2C)? I was trying to argue for a panel connector type and stop doing all these internal things because like you point out, it kinda doesn't, only the external connectors are relevant to users. But it didn't stick anywhere yet, we keep adding more connector types and then having to update userspace, which should map these all to "it's the panel" or something like that. But also since various technicolor abbreviations are about as useful to end-users as "unknown" it really doesn't matter, so I'm happy to let this bikeshed get a tad fancier every year :-) -Daniel > Gr{oetje,eeting}s, > > Geert > > -- > Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org > > In personal conversations with technical people, I call myself a hacker. But > when I'm talking to journalists I just say "programmer" or something like that. > -- Linus Torvalds
Hi Am 01.02.22 um 18:00 schrieb Geert Uytterhoeven: > Hi Thomas, > > On Tue, Feb 1, 2022 at 5:16 PM Thomas Zimmermann <tzimmermann@suse.de> wrote: >> Am 31.01.22 um 11:18 schrieb Javier Martinez Canillas: >>> Another thing that's missing is a DRM_MODE_CONNECTOR_I2C, because I used for >>> now a DRM_MODE_CONNECTOR_Unknown. >> >> That might have implications on userspace. Maybe ask around. (Not that >> we actually run userspace on the device). > > Looking at the list of connector types (and wondering if we're gonna > need more when converting existing fbdev drivers to drm drivers), > there seem to be two different families of connector types, for > 1. transports between CRTC and display (e.g. VGA, DVID, HDMI), > 2. transports between CPU and CRTC (e.g. SPI, possibly USB, and > the proposed I2C)? I think I had a similar discussion when we merged the gud driver. gud is a driver for a RasPi-based usb display adapter. My point was that USB is just an internal transport bus, like PCI. But that wasn't convincing. So now we have USB and other busses as connector types. My preference would be to use a panel type as Daniel suggested; and maybe 'Unknown' for a few special cases. Best regards Thomas > > Gr{oetje,eeting}s, > > Geert > > -- > Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org > > In personal conversations with technical people, I call myself a hacker. But > when I'm talking to journalists I just say "programmer" or something like that. > -- Linus Torvalds
Since we got a maintainer for fbdev, I would like to unorphan fbtft (with the idea of sending PRs to Helge) and move it out of staging since there is no more clean up work expected and no more drivers either. Thoughts? Andy Shevchenko (4): fbtft: Unorphan the driver fbtft: Move driver out from staging fbtft: Kill outdated documentation fbtft: Replace 'depends on FB_TFT' by 'if FB_TFT ... endif' MAINTAINERS | 6 ++-- drivers/staging/Kconfig | 2 -- drivers/staging/Makefile | 1 - drivers/staging/fbtft/README | 32 ------------------ drivers/staging/fbtft/TODO | 3 -- drivers/video/Kconfig | 1 + drivers/video/Makefile | 1 + drivers/{staging => video}/fbtft/Kconfig | 33 +++---------------- drivers/{staging => video}/fbtft/Makefile | 0 .../{staging => video}/fbtft/fb_agm1264k-fl.c | 0 .../{staging => video}/fbtft/fb_bd663474.c | 0 .../{staging => video}/fbtft/fb_hx8340bn.c | 0 drivers/{staging => video}/fbtft/fb_hx8347d.c | 0 drivers/{staging => video}/fbtft/fb_hx8353d.c | 0 drivers/{staging => video}/fbtft/fb_hx8357d.c | 0 drivers/{staging => video}/fbtft/fb_hx8357d.h | 0 drivers/{staging => video}/fbtft/fb_ili9163.c | 0 drivers/{staging => video}/fbtft/fb_ili9320.c | 0 drivers/{staging => video}/fbtft/fb_ili9325.c | 0 drivers/{staging => video}/fbtft/fb_ili9340.c | 0 drivers/{staging => video}/fbtft/fb_ili9341.c | 0 drivers/{staging => video}/fbtft/fb_ili9481.c | 0 drivers/{staging => video}/fbtft/fb_ili9486.c | 0 drivers/{staging => video}/fbtft/fb_pcd8544.c | 0 drivers/{staging => video}/fbtft/fb_ra8875.c | 0 drivers/{staging => video}/fbtft/fb_s6d02a1.c | 0 drivers/{staging => video}/fbtft/fb_s6d1121.c | 0 drivers/{staging => video}/fbtft/fb_seps525.c | 0 drivers/{staging => video}/fbtft/fb_sh1106.c | 0 drivers/{staging => video}/fbtft/fb_ssd1289.c | 0 drivers/{staging => video}/fbtft/fb_ssd1305.c | 0 drivers/{staging => video}/fbtft/fb_ssd1306.c | 0 drivers/{staging => video}/fbtft/fb_ssd1325.c | 0 drivers/{staging => video}/fbtft/fb_ssd1331.c | 0 drivers/{staging => video}/fbtft/fb_ssd1351.c | 0 drivers/{staging => video}/fbtft/fb_st7735r.c | 0 drivers/{staging => video}/fbtft/fb_st7789v.c | 0 drivers/{staging => video}/fbtft/fb_tinylcd.c | 0 drivers/{staging => video}/fbtft/fb_tls8204.c | 0 drivers/{staging => video}/fbtft/fb_uc1611.c | 0 drivers/{staging => video}/fbtft/fb_uc1701.c | 0 .../{staging => video}/fbtft/fb_upd161704.c | 0 drivers/{staging => video}/fbtft/fbtft-bus.c | 0 drivers/{staging => video}/fbtft/fbtft-core.c | 0 drivers/{staging => video}/fbtft/fbtft-io.c | 0 .../{staging => video}/fbtft/fbtft-sysfs.c | 0 drivers/{staging => video}/fbtft/fbtft.h | 0 drivers/{staging => video}/fbtft/internal.h | 0 48 files changed, 10 insertions(+), 69 deletions(-) delete mode 100644 drivers/staging/fbtft/README delete mode 100644 drivers/staging/fbtft/TODO rename drivers/{staging => video}/fbtft/Kconfig (89%) rename drivers/{staging => video}/fbtft/Makefile (100%) rename drivers/{staging => video}/fbtft/fb_agm1264k-fl.c (100%) rename drivers/{staging => video}/fbtft/fb_bd663474.c (100%) rename drivers/{staging => video}/fbtft/fb_hx8340bn.c (100%) rename drivers/{staging => video}/fbtft/fb_hx8347d.c (100%) rename drivers/{staging => video}/fbtft/fb_hx8353d.c (100%) rename drivers/{staging => video}/fbtft/fb_hx8357d.c (100%) rename drivers/{staging => video}/fbtft/fb_hx8357d.h (100%) rename drivers/{staging => video}/fbtft/fb_ili9163.c (100%) rename drivers/{staging => video}/fbtft/fb_ili9320.c (100%) rename drivers/{staging => video}/fbtft/fb_ili9325.c (100%) rename drivers/{staging => video}/fbtft/fb_ili9340.c (100%) rename drivers/{staging => video}/fbtft/fb_ili9341.c (100%) rename drivers/{staging => video}/fbtft/fb_ili9481.c (100%) rename drivers/{staging => video}/fbtft/fb_ili9486.c (100%) rename drivers/{staging => video}/fbtft/fb_pcd8544.c (100%) rename drivers/{staging => video}/fbtft/fb_ra8875.c (100%) rename drivers/{staging => video}/fbtft/fb_s6d02a1.c (100%) rename drivers/{staging => video}/fbtft/fb_s6d1121.c (100%) rename drivers/{staging => video}/fbtft/fb_seps525.c (100%) rename drivers/{staging => video}/fbtft/fb_sh1106.c (100%) rename drivers/{staging => video}/fbtft/fb_ssd1289.c (100%) rename drivers/{staging => video}/fbtft/fb_ssd1305.c (100%) rename drivers/{staging => video}/fbtft/fb_ssd1306.c (100%) rename drivers/{staging => video}/fbtft/fb_ssd1325.c (100%) rename drivers/{staging => video}/fbtft/fb_ssd1331.c (100%) rename drivers/{staging => video}/fbtft/fb_ssd1351.c (100%) rename drivers/{staging => video}/fbtft/fb_st7735r.c (100%) rename drivers/{staging => video}/fbtft/fb_st7789v.c (100%) rename drivers/{staging => video}/fbtft/fb_tinylcd.c (100%) rename drivers/{staging => video}/fbtft/fb_tls8204.c (100%) rename drivers/{staging => video}/fbtft/fb_uc1611.c (100%) rename drivers/{staging => video}/fbtft/fb_uc1701.c (100%) rename drivers/{staging => video}/fbtft/fb_upd161704.c (100%) rename drivers/{staging => video}/fbtft/fbtft-bus.c (100%) rename drivers/{staging => video}/fbtft/fbtft-core.c (100%) rename drivers/{staging => video}/fbtft/fbtft-io.c (100%) rename drivers/{staging => video}/fbtft/fbtft-sysfs.c (100%) rename drivers/{staging => video}/fbtft/fbtft.h (100%) rename drivers/{staging => video}/fbtft/internal.h (100%)