| Message ID | cover.1621583562.git.geert+renesas@glider.be |
|---|---|
| Headers | show |
| Series | pcf857x: DTS fixes and DT binding to json-schema conversion | expand |
Hi Linus, On Fri, May 21, 2021 at 12:04 PM Linus Walleij <linus.walleij@linaro.org> wrote: > On Fri, May 21, 2021 at 9:54 AM Geert Uytterhoeven > <geert+renesas@glider.be> wrote: > > Convert the PCF857x-compatible I/O expanders Device Tree binding > > documentation to json-schema. > > > > Document missing compatible values, properties, and gpio hogs. > > > > Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> > > (...) > > Perhaps the "ti,pcf8575" construct should be removed, and the few users > > fixed instead? > > You would rather list it as deprecated I think? > It is ABI... All DTS files use the "nxp,pcf8575" fallback, except for arch/x86/platform/ce4100/falconfalls.dts. The latter ain't working with Linux, as the Linux driver doesn't match against "ti,pcf8575"... > > + gpio-controller: true > > So this is implicitly using the generic schema in > /dtschema/schemas/gpio/gpio.yaml if you leave it out: Documentation/devicetree/bindings/gpio/nxp,pcf8575.yaml: ignoring, error in schema: properties warning: no schema found in file: Documentation/devicetree/bindings/gpio/nxp,pcf8575.yaml Documentation/devicetree/bindings/gpio/nxp,pcf8575.yaml: properties: 'gpio-controller' is a dependency of '#gpio-cells' from schema $id: http://devicetree.org/meta-schemas/gpios.yaml# > > + lines-initial-states: > > + $ref: /schemas/types.yaml#/definitions/uint32 > > + description: > > + Bitmask that specifies the initial state of each line. > > + When a bit is set to zero, the corresponding line will be initialized to > > + the input (pulled-up) state. > > + When the bit is set to one, the line will be initialized to the > > + low-level output state. > > + If the property is not specified all lines will be initialized to the > > + input state. > > Is this something we standardized or something that should > actually be a custom "nxp," property we just missed it? > (Looks like the latter... oh well, now it is there.) Too late for an "nxp," prefix. See the NOTE in drivers/gpio/gpio-pcf857x.c: /* NOTE: these chips have strange "quasi-bidirectional" I/O pins. * We can't actually know whether a pin is configured (a) as output * and driving the signal low, or (b) as input and reporting a low * value ... without knowing the last value written since the chip * came out of reset (if any). We can't read the latched output. * * In short, the only reliable solution for setting up pin direction * is to do it explicitly. The setup() method can do that, but it * may cause transient glitching since it can't know the last value * written (some pins may need to be driven low). * * Using n_latch avoids that trouble. When left initialized to zero, * our software copy of the "latch" then matches the chip's all-ones * reset state. Otherwise it flags pins to be driven low. */ > > +patternProperties: > > + "^(hog-[0-9]+|.+-hog(-[0-9]+)?)$": > > + type: object > > But this is already in > /dtschema/schemas/gpio/gpio-hog.yaml > for nodename, isn't that where it properly belongs? > > I'm however confused here Rob will know what to do. If we leave this out, something still has to refer to it? I see no other binding doing that... Gr{oetje,eeting}s, Geert
On Fri, May 21, 2021 at 12:23:47PM +0200, Geert Uytterhoeven wrote: > Hi Linus, > > On Fri, May 21, 2021 at 12:04 PM Linus Walleij <linus.walleij@linaro.org> wrote: > > On Fri, May 21, 2021 at 9:54 AM Geert Uytterhoeven > > <geert+renesas@glider.be> wrote: > > > Convert the PCF857x-compatible I/O expanders Device Tree binding > > > documentation to json-schema. > > > > > > Document missing compatible values, properties, and gpio hogs. > > > > > > Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> > > > > (...) > > > Perhaps the "ti,pcf8575" construct should be removed, and the few users > > > fixed instead? > > > > You would rather list it as deprecated I think? > > It is ABI... > > All DTS files use the "nxp,pcf8575" fallback, except for > arch/x86/platform/ce4100/falconfalls.dts. > The latter ain't working with Linux, as the Linux driver doesn't > match against "ti,pcf8575"... Perhaps can it just be removed? > > > > + gpio-controller: true > > > > So this is implicitly using the generic schema in > > /dtschema/schemas/gpio/gpio.yaml > > if you leave it out: > > Documentation/devicetree/bindings/gpio/nxp,pcf8575.yaml: ignoring, > error in schema: properties > warning: no schema found in file: > Documentation/devicetree/bindings/gpio/nxp,pcf8575.yaml > Documentation/devicetree/bindings/gpio/nxp,pcf8575.yaml: > properties: 'gpio-controller' is a dependency of '#gpio-cells' > from schema $id: http://devicetree.org/meta-schemas/gpios.yaml# > > > > + lines-initial-states: > > > + $ref: /schemas/types.yaml#/definitions/uint32 > > > + description: > > > + Bitmask that specifies the initial state of each line. > > > + When a bit is set to zero, the corresponding line will be initialized to > > > + the input (pulled-up) state. > > > + When the bit is set to one, the line will be initialized to the > > > + low-level output state. > > > + If the property is not specified all lines will be initialized to the > > > + input state. > > > > Is this something we standardized or something that should > > actually be a custom "nxp," property we just missed it? > > (Looks like the latter... oh well, now it is there.) > > Too late for an "nxp," prefix. > See the NOTE in drivers/gpio/gpio-pcf857x.c: > > /* NOTE: these chips have strange "quasi-bidirectional" I/O pins. > * We can't actually know whether a pin is configured (a) as output > * and driving the signal low, or (b) as input and reporting a low > * value ... without knowing the last value written since the chip > * came out of reset (if any). We can't read the latched output. > * > * In short, the only reliable solution for setting up pin direction > * is to do it explicitly. The setup() method can do that, but it > * may cause transient glitching since it can't know the last value > * written (some pins may need to be driven low). > * > * Using n_latch avoids that trouble. When left initialized to zero, > * our software copy of the "latch" then matches the chip's all-ones > * reset state. Otherwise it flags pins to be driven low. > */ > > > > +patternProperties: > > > + "^(hog-[0-9]+|.+-hog(-[0-9]+)?)$": > > > + type: object > > > > But this is already in > > /dtschema/schemas/gpio/gpio-hog.yaml > > for nodename, isn't that where it properly belongs? > > > > I'm however confused here Rob will know what to do. This one is a bit odd. > If we leave this out, something still has to refer to it? > I see no other binding doing that... It's selected by 'gpio-hog' being present, but here you need to make sure that's the case. And I would hope you could define the node name to be just 1 of the 2 cases. Rob
Hi Rob, On Fri, May 21, 2021 at 8:24 PM Rob Herring <robh@kernel.org> wrote: > On Fri, May 21, 2021 at 12:23:47PM +0200, Geert Uytterhoeven wrote: > > On Fri, May 21, 2021 at 12:04 PM Linus Walleij <linus.walleij@linaro.org> wrote: > > > On Fri, May 21, 2021 at 9:54 AM Geert Uytterhoeven > > > <geert+renesas@glider.be> wrote: > > > > Convert the PCF857x-compatible I/O expanders Device Tree binding > > > > documentation to json-schema. > > > > > > > > Document missing compatible values, properties, and gpio hogs. > > > > > > > > Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> > > > > > > (...) > > > > Perhaps the "ti,pcf8575" construct should be removed, and the few users > > > > fixed instead? > > > > > > You would rather list it as deprecated I think? > > > It is ABI... > > > > All DTS files use the "nxp,pcf8575" fallback, except for > > arch/x86/platform/ce4100/falconfalls.dts. > > The latter ain't working with Linux, as the Linux driver doesn't > > match against "ti,pcf8575"... Correction: i2c_device_id-based matching ignores the vendor part of the compatible value. One day this is gonna bite us... > Perhaps can it just be removed? I think so. All other users of similar I2C GPIO expanders just use the compatible values of the original NXP parts. > > > > +patternProperties: > > > > + "^(hog-[0-9]+|.+-hog(-[0-9]+)?)$": > > > > + type: object > > > > > > But this is already in > > > /dtschema/schemas/gpio/gpio-hog.yaml > > > for nodename, isn't that where it properly belongs? > > > > > > I'm however confused here Rob will know what to do. > > This one is a bit odd. > > > If we leave this out, something still has to refer to it? > > I see no other binding doing that... > > It's selected by 'gpio-hog' being present, but here you need to make > sure that's the case. OK. Fixed. > And I would hope you could define the node name to be just 1 of the 2 > cases. Yep, the latter is fine. Gr{oetje,eeting}s, Geert