| Message ID | 20220109232003.2573924-4-gsomlo@gmail.com |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [v11,1/3] MAINTAINERS: co-maintain LiteX platform | expand |
On Sun, Jan 09, 2022 at 06:20:03PM -0500, Gabriel Somlo wrote: > LiteX (https://github.com/enjoy-digital/litex) is a SoC framework > that targets FPGAs. LiteSDCard is a small footprint, configurable > SDCard core commonly used in LiteX designs. > > The driver was first written in May 2020 and has been maintained > cooperatively by the LiteX community. Thanks to all contributors! > > Co-developed-by: Kamil Rakoczy <krakoczy@antmicro.com> > Signed-off-by: Kamil Rakoczy <krakoczy@antmicro.com> > Co-developed-by: Maciej Dudek <mdudek@internships.antmicro.com> > Signed-off-by: Maciej Dudek <mdudek@internships.antmicro.com> > Co-developed-by: Paul Mackerras <paulus@ozlabs.org> > Signed-off-by: Paul Mackerras <paulus@ozlabs.org> > Signed-off-by: Gabriel Somlo <gsomlo@gmail.com> > Reviewed-by: Joel Stanley <joel@jms.id.au> > Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> > --- > > New in v11: > - picked up r/b from Andy > drivers/mmc/host/litex_mmc.c: > - defensive coding of litex_mmc_interrupt() return logic > - remove `dev` member of `struct litex_mmc_host`, only used during probe > > >New in v10: > >drivers/mmc/host/litex_mmc.c: > > - group `linux/mmc/*` includes by themselves > > - clean-up of `return` style (multiple locations throughout source) > > - create `mmc_free_host()` wrapper for use with > > `devm_add_action_or_reset()` > > - use GFP_KERNEL with `dmam_alloc_coherent()` > > > >>New in v9: > >>drivers/mmc/host/Kconfig: > >> - fix OF dependency > >>drivers/mmc/host/litex_mmc.c: > >> - remove `linux/of.h` include, no longer needed since dropping > >> `of_match_ptr()` > >> - add `linux/mod_devicetable.h` include > >> - use devm_action_or_reset() to devm-ify mmc_alloc_host(), and obviate > >> the need to call mmc_free_host() explicitly during either probe() > >> error path or during remove() > >> > >>>New in v8: > >>> - remove `Cc:` lines from commit blurb > >>>drivers/mmc/host/litex_mmc.c: > >>> - fix file header comment (for real, this time) > >>> - add explicit `bits.h` include > >>> - remove `of_match_ptr()` wrapper from around .of_match_table argument > >>> - fix devm ordering issues: use `devm_request_irq()`, which precludes > >>> the need to call `free_irq()` on `probe()` error path or from `remove()` > >>> > >>>>New in v7: > >>>>drivers/mmc/host/Kconfig: > >>>> - added module name in LiteSDCard Kconfig entry > >>>>drivers/mmc/host/litex_mmc.c: > >>>> - fixed comment formatting, ordering, and capitalization throughout > >>>> the entire file > >>>> - sorted header #include statements > >>>> - removed redundant parantheses in readx_poll_timeout() condition > >>>> - explicit handling of readx_poll_timeout() timeout scenarios > >>>> - dev_err() used in litex_mmc_sdcard_wait_done() > >>>> - use memcpy_fromio() to grab command response > >>>> - no need to apply 0xffff mask to a 32-bit value right-shifted by 16 > >>>> (host->resp[3]) > >>>> - use clamp() instead of min(max(...)...) > >>>> - reworked platform_get_irq_optional() error handling logic > >>>> - no need to explicitly zero host->irq, kzalloc() does that already > >>>> - added missing free_irq() in litex_mmc_probe() error path > >>>> - reordered calls inside litex_mmc_remove() (calling mmc_free_host() > >>>> before free_irq() > >>>> > >>>>>New in v6: > >>>>> - fix handling of deferred probe vs. platform_get_irq_optional() > >>>>> - don't #ifdef dma_set_mask_and_coherent(), since it automatically > >>>>> does the right thing on both 32- and 64-bit DMA capable arches > >>>>> - remove MMC_CAP2_FULL_PWR_CYCLE, add MMC_CAP2_NO_MMC to list of > >>>>> hardcoded capabilities during litex_mmc_probe() > >>>>> - hardcode mmc->ocr_avail to the full 2.7-3.6V range allowed by the > >>>>> SDCard spec (the LiteSDCard device doesn't accept software > >>>>> configuration) > >>>>> > >>>>>>New in v5: > >>>>>> - shorter #define constant names (cosmetic, make them less unwieldy) > >>>>>> - picked up reviewed-by Joel > >>>>>> > >>>>>>>New in v4: > >>>>>>> - struct litex_mmc_host fields re-ordered so that `pahole` reports > >>>>>>> no holes on either 32- or 64-bit builds > >>>>>>> - litex_mmc_set_bus_width() now encapsulates check for > >>>>>>> host->is_bus_width_set > >>>>>>> - litex_mmc_request() - factor out dma data setup into separate > >>>>>>> helper function: litex_mmc_do_dma() > >>>>>>> > >>>>>>>> New in v3: > >>>>>>>> - fixed function signature (no line split), and naming (litex_mmc_*) > >>>>>>>> - more informative MODULE_AUTHOR() entries > >>>>>>>> - also added matching "Copyright" entries in file header > >>>>>>>> - fixed description and dependencies in Kconfig > >>>>>>>> - removed magic constants > >>>>>>>> - removed litex_map_status(), have sdcard_wait_done() return *real* > >>>>>>>> error codes directly instead. > >>>>>>>> - streamlined litex_mmc_reponse_len() > >>>>>>>> - call litex_mmc_set_bus_width() only once, and ensure it returns > >>>>>>>> correct error code(s) > >>>>>>>> - use readx_poll_timeout() -- more concise -- instead of > >>>>>>>> read_poll_timeout() > >>>>>>>> - use dev_err() in litex_mmc_send_cmd() (instead of pr_err()) > >>>>>>>> - litex_mmc_setclk() will update host->clock before returning > >>>>>>>> - separate irq initialization into its own function, > >>>>>>>> litex_mmc_irq_init() > >>>>>>>> - document rationale for f_min, f_max > >>>>>>>> - use dmam_alloc_coherent(), which simplifies cleanup significantly > >>>>>>>> - bump dma_set_mask_and_coherent() to 64-bits on suitable > >>>>>>>> architectures > >>>>>>>> - clock source picked up from dedicated DT clock reference property > >>>>>>>> - remove gpio card-detect logic (needs testing and a dt binding > >>>>>>>> example before being eligible for upstream inclusion) > >>>>>>>> - large `if (data) { ... }` block in litex_mmc_request() left as-is, > >>>>>>>> there are too many variables shared with the rest of the parent > >>>>>>>> function body to easily separate (e.g., `len`, `transfer`, `direct`). > >>>>>>>> If this is indeed a blocker, I can take another shot at refactoring > >>>>>>>> it in a future revision! > > drivers/mmc/host/Kconfig | 9 + > drivers/mmc/host/Makefile | 1 + > drivers/mmc/host/litex_mmc.c | 657 +++++++++++++++++++++++++++++++++++ > 3 files changed, 667 insertions(+) > create mode 100644 drivers/mmc/host/litex_mmc.c > > diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig > index 5af8494c31b5..8f661f52b502 100644 > --- a/drivers/mmc/host/Kconfig > +++ b/drivers/mmc/host/Kconfig > @@ -1093,3 +1093,12 @@ config MMC_OWL > > config MMC_SDHCI_EXTERNAL_DMA > bool > + > +config MMC_LITEX > + tristate "LiteX MMC Host Controller support" > + depends on ((PPC_MICROWATT || LITEX) && OF) || COMPILE_TEST > + help > + This selects support for the MMC Host Controller found in LiteX SoCs. See comment below. > + To compile this driver as a module, choose M here: the > + module will be called litex_mmc. Can we add this here too? If unsure, say N. > diff --git a/drivers/mmc/host/Makefile b/drivers/mmc/host/Makefile > index ea36d379bd3c..4e4ceb32c4b4 100644 > --- a/drivers/mmc/host/Makefile > +++ b/drivers/mmc/host/Makefile > @@ -101,6 +101,7 @@ obj-$(CONFIG_MMC_CQHCI) += cqhci.o > cqhci-y += cqhci-core.o > cqhci-$(CONFIG_MMC_CRYPTO) += cqhci-crypto.o > obj-$(CONFIG_MMC_HSQ) += mmc_hsq.o > +obj-$(CONFIG_MMC_LITEX) += litex_mmc.o > > ifeq ($(CONFIG_CB710_DEBUG),y) > CFLAGS-cb710-mmc += -DDEBUG > diff --git a/drivers/mmc/host/litex_mmc.c b/drivers/mmc/host/litex_mmc.c > new file mode 100644 > index 000000000000..cc2848030e6b > --- /dev/null > +++ b/drivers/mmc/host/litex_mmc.c > @@ -0,0 +1,657 @@ ... > + > + /* Initialize clock source */ > + clk = devm_clk_get(dev, NULL); > + if (IS_ERR(clk)) > + return dev_err_probe(dev, PTR_ERR(clk), "can't get clock\n"); > + host->ref_clk = clk_get_rate(clk); Note, we used to have: cpu = of_get_next_cpu_node(NULL); ret = of_property_read_u32(cpu, "clock-frequency", &host->freq); of_node_put(cpu); if (ret) { dev_err(&pdev->dev, "No \"clock-frequency\" property in DT\n"); goto err_free_host; } As we agree, this worked but was hacky. The new use of devm_clk_get above uses the COMMON_CLK framework. Which is great but OpenRISC doesn't yet support COMMON_CLK, so this driver no longer works on OpenRISC. I think the ideal thing is to not change the driver code and I will just add support for COMMON_CLK on openrisc (already done and tested). But as we discussed off e-mail I think we should change the config constraints to. depends on ((PPC_MICROWATT || LITEX) && OF && HAVE_CLK) || COMPILE_TEST -Stafford
On Tue, Jan 11, 2022 at 07:07:47AM +0900, Stafford Horne wrote: > On Sun, Jan 09, 2022 at 06:20:03PM -0500, Gabriel Somlo wrote: > > LiteX (https://github.com/enjoy-digital/litex) is a SoC framework > > that targets FPGAs. LiteSDCard is a small footprint, configurable > > SDCard core commonly used in LiteX designs. > > > > The driver was first written in May 2020 and has been maintained > > cooperatively by the LiteX community. Thanks to all contributors! > > > > Co-developed-by: Kamil Rakoczy <krakoczy@antmicro.com> > > Signed-off-by: Kamil Rakoczy <krakoczy@antmicro.com> > > Co-developed-by: Maciej Dudek <mdudek@internships.antmicro.com> > > Signed-off-by: Maciej Dudek <mdudek@internships.antmicro.com> > > Co-developed-by: Paul Mackerras <paulus@ozlabs.org> > > Signed-off-by: Paul Mackerras <paulus@ozlabs.org> > > Signed-off-by: Gabriel Somlo <gsomlo@gmail.com> > > Reviewed-by: Joel Stanley <joel@jms.id.au> > > Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> > > --- > > > > New in v11: > > - picked up r/b from Andy > > drivers/mmc/host/litex_mmc.c: > > - defensive coding of litex_mmc_interrupt() return logic > > - remove `dev` member of `struct litex_mmc_host`, only used during probe > > > > >New in v10: > > >drivers/mmc/host/litex_mmc.c: > > > - group `linux/mmc/*` includes by themselves > > > - clean-up of `return` style (multiple locations throughout source) > > > - create `mmc_free_host()` wrapper for use with > > > `devm_add_action_or_reset()` > > > - use GFP_KERNEL with `dmam_alloc_coherent()` > > > > > >>New in v9: > > >>drivers/mmc/host/Kconfig: > > >> - fix OF dependency > > >>drivers/mmc/host/litex_mmc.c: > > >> - remove `linux/of.h` include, no longer needed since dropping > > >> `of_match_ptr()` > > >> - add `linux/mod_devicetable.h` include > > >> - use devm_action_or_reset() to devm-ify mmc_alloc_host(), and obviate > > >> the need to call mmc_free_host() explicitly during either probe() > > >> error path or during remove() > > >> > > >>>New in v8: > > >>> - remove `Cc:` lines from commit blurb > > >>>drivers/mmc/host/litex_mmc.c: > > >>> - fix file header comment (for real, this time) > > >>> - add explicit `bits.h` include > > >>> - remove `of_match_ptr()` wrapper from around .of_match_table argument > > >>> - fix devm ordering issues: use `devm_request_irq()`, which precludes > > >>> the need to call `free_irq()` on `probe()` error path or from `remove()` > > >>> > > >>>>New in v7: > > >>>>drivers/mmc/host/Kconfig: > > >>>> - added module name in LiteSDCard Kconfig entry > > >>>>drivers/mmc/host/litex_mmc.c: > > >>>> - fixed comment formatting, ordering, and capitalization throughout > > >>>> the entire file > > >>>> - sorted header #include statements > > >>>> - removed redundant parantheses in readx_poll_timeout() condition > > >>>> - explicit handling of readx_poll_timeout() timeout scenarios > > >>>> - dev_err() used in litex_mmc_sdcard_wait_done() > > >>>> - use memcpy_fromio() to grab command response > > >>>> - no need to apply 0xffff mask to a 32-bit value right-shifted by 16 > > >>>> (host->resp[3]) > > >>>> - use clamp() instead of min(max(...)...) > > >>>> - reworked platform_get_irq_optional() error handling logic > > >>>> - no need to explicitly zero host->irq, kzalloc() does that already > > >>>> - added missing free_irq() in litex_mmc_probe() error path > > >>>> - reordered calls inside litex_mmc_remove() (calling mmc_free_host() > > >>>> before free_irq() > > >>>> > > >>>>>New in v6: > > >>>>> - fix handling of deferred probe vs. platform_get_irq_optional() > > >>>>> - don't #ifdef dma_set_mask_and_coherent(), since it automatically > > >>>>> does the right thing on both 32- and 64-bit DMA capable arches > > >>>>> - remove MMC_CAP2_FULL_PWR_CYCLE, add MMC_CAP2_NO_MMC to list of > > >>>>> hardcoded capabilities during litex_mmc_probe() > > >>>>> - hardcode mmc->ocr_avail to the full 2.7-3.6V range allowed by the > > >>>>> SDCard spec (the LiteSDCard device doesn't accept software > > >>>>> configuration) > > >>>>> > > >>>>>>New in v5: > > >>>>>> - shorter #define constant names (cosmetic, make them less unwieldy) > > >>>>>> - picked up reviewed-by Joel > > >>>>>> > > >>>>>>>New in v4: > > >>>>>>> - struct litex_mmc_host fields re-ordered so that `pahole` reports > > >>>>>>> no holes on either 32- or 64-bit builds > > >>>>>>> - litex_mmc_set_bus_width() now encapsulates check for > > >>>>>>> host->is_bus_width_set > > >>>>>>> - litex_mmc_request() - factor out dma data setup into separate > > >>>>>>> helper function: litex_mmc_do_dma() > > >>>>>>> > > >>>>>>>> New in v3: > > >>>>>>>> - fixed function signature (no line split), and naming (litex_mmc_*) > > >>>>>>>> - more informative MODULE_AUTHOR() entries > > >>>>>>>> - also added matching "Copyright" entries in file header > > >>>>>>>> - fixed description and dependencies in Kconfig > > >>>>>>>> - removed magic constants > > >>>>>>>> - removed litex_map_status(), have sdcard_wait_done() return *real* > > >>>>>>>> error codes directly instead. > > >>>>>>>> - streamlined litex_mmc_reponse_len() > > >>>>>>>> - call litex_mmc_set_bus_width() only once, and ensure it returns > > >>>>>>>> correct error code(s) > > >>>>>>>> - use readx_poll_timeout() -- more concise -- instead of > > >>>>>>>> read_poll_timeout() > > >>>>>>>> - use dev_err() in litex_mmc_send_cmd() (instead of pr_err()) > > >>>>>>>> - litex_mmc_setclk() will update host->clock before returning > > >>>>>>>> - separate irq initialization into its own function, > > >>>>>>>> litex_mmc_irq_init() > > >>>>>>>> - document rationale for f_min, f_max > > >>>>>>>> - use dmam_alloc_coherent(), which simplifies cleanup significantly > > >>>>>>>> - bump dma_set_mask_and_coherent() to 64-bits on suitable > > >>>>>>>> architectures > > >>>>>>>> - clock source picked up from dedicated DT clock reference property > > >>>>>>>> - remove gpio card-detect logic (needs testing and a dt binding > > >>>>>>>> example before being eligible for upstream inclusion) > > >>>>>>>> - large `if (data) { ... }` block in litex_mmc_request() left as-is, > > >>>>>>>> there are too many variables shared with the rest of the parent > > >>>>>>>> function body to easily separate (e.g., `len`, `transfer`, `direct`). > > >>>>>>>> If this is indeed a blocker, I can take another shot at refactoring > > >>>>>>>> it in a future revision! > > > > drivers/mmc/host/Kconfig | 9 + > > drivers/mmc/host/Makefile | 1 + > > drivers/mmc/host/litex_mmc.c | 657 +++++++++++++++++++++++++++++++++++ > > 3 files changed, 667 insertions(+) > > create mode 100644 drivers/mmc/host/litex_mmc.c > > > > diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig > > index 5af8494c31b5..8f661f52b502 100644 > > --- a/drivers/mmc/host/Kconfig > > +++ b/drivers/mmc/host/Kconfig > > @@ -1093,3 +1093,12 @@ config MMC_OWL > > > > config MMC_SDHCI_EXTERNAL_DMA > > bool > > + > > +config MMC_LITEX > > + tristate "LiteX MMC Host Controller support" > > + depends on ((PPC_MICROWATT || LITEX) && OF) || COMPILE_TEST > > + help > > + This selects support for the MMC Host Controller found in LiteX SoCs. > > See comment below. > > > + To compile this driver as a module, choose M here: the > > + module will be called litex_mmc. > > Can we add this here too? > > If unsure, say N. OK, lined up for v12. > > diff --git a/drivers/mmc/host/Makefile b/drivers/mmc/host/Makefile > > index ea36d379bd3c..4e4ceb32c4b4 100644 > > --- a/drivers/mmc/host/Makefile > > +++ b/drivers/mmc/host/Makefile > > @@ -101,6 +101,7 @@ obj-$(CONFIG_MMC_CQHCI) += cqhci.o > > cqhci-y += cqhci-core.o > > cqhci-$(CONFIG_MMC_CRYPTO) += cqhci-crypto.o > > obj-$(CONFIG_MMC_HSQ) += mmc_hsq.o > > +obj-$(CONFIG_MMC_LITEX) += litex_mmc.o > > > > ifeq ($(CONFIG_CB710_DEBUG),y) > > CFLAGS-cb710-mmc += -DDEBUG > > diff --git a/drivers/mmc/host/litex_mmc.c b/drivers/mmc/host/litex_mmc.c > > new file mode 100644 > > index 000000000000..cc2848030e6b > > --- /dev/null > > +++ b/drivers/mmc/host/litex_mmc.c > > @@ -0,0 +1,657 @@ > ... > > + > > + /* Initialize clock source */ > > + clk = devm_clk_get(dev, NULL); > > + if (IS_ERR(clk)) > > + return dev_err_probe(dev, PTR_ERR(clk), "can't get clock\n"); > > + host->ref_clk = clk_get_rate(clk); > > Note, we used to have: > > cpu = of_get_next_cpu_node(NULL); > ret = of_property_read_u32(cpu, "clock-frequency", &host->freq); > of_node_put(cpu); > if (ret) { > dev_err(&pdev->dev, "No \"clock-frequency\" property in DT\n"); > goto err_free_host; > } > > As we agree, this worked but was hacky. The new use of devm_clk_get above uses > the COMMON_CLK framework. Which is great but OpenRISC doesn't yet support > COMMON_CLK, so this driver no longer works on OpenRISC. > > I think the ideal thing is to not change the driver code and I will just add > support for COMMON_CLK on openrisc (already done and tested). But as we > discussed off e-mail I think we should change the config constraints to. > > depends on ((PPC_MICROWATT || LITEX) && OF && HAVE_CLK) || COMPILE_TEST OK, also lined up for v12. I'll probably send out v12 in a few hours -- thanks for the suggestions and testing! Best, --Gabriel
On Tue, Jan 11, 2022 at 07:15:42AM +0900, Stafford Horne wrote: > On Sun, Jan 09, 2022 at 06:20:03PM -0500, Gabriel Somlo wrote: > > LiteX (https://github.com/enjoy-digital/litex) is a SoC framework > > that targets FPGAs. LiteSDCard is a small footprint, configurable > > SDCard core commonly used in LiteX designs. > > > > The driver was first written in May 2020 and has been maintained > > cooperatively by the LiteX community. Thanks to all contributors! > > > > Co-developed-by: Kamil Rakoczy <krakoczy@antmicro.com> > > Signed-off-by: Kamil Rakoczy <krakoczy@antmicro.com> > > Co-developed-by: Maciej Dudek <mdudek@internships.antmicro.com> > > Signed-off-by: Maciej Dudek <mdudek@internships.antmicro.com> > > Co-developed-by: Paul Mackerras <paulus@ozlabs.org> > > Signed-off-by: Paul Mackerras <paulus@ozlabs.org> > > Signed-off-by: Gabriel Somlo <gsomlo@gmail.com> > > Reviewed-by: Joel Stanley <joel@jms.id.au> > > Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> > > --- > > > ... > > +static int litex_mmc_probe(struct platform_device *pdev) > > +{ > > + struct device *dev = &pdev->dev; > > + struct litex_mmc_host *host; > > + struct mmc_host *mmc; > > + struct clk *clk; > > + int ret; > > + > > + /* > > + * NOTE: defaults to max_[req,seg]_size=PAGE_SIZE, max_blk_size=512, > > + * and max_blk_count accordingly set to 8; > > + * If for some reason we need to modify max_blk_count, we must also > > + * re-calculate `max_[req,seg]_size = max_blk_size * max_blk_count;` > > + */ > > + mmc = mmc_alloc_host(sizeof(struct litex_mmc_host), dev); > > + if (!mmc) > > + return -ENOMEM; > > + > > + ret = devm_add_action_or_reset(dev, litex_mmc_free_host_wrapper, mmc); > > + if (ret) > > + return dev_err_probe(dev, ret, > > + "Can't register mmc_free_host action\n"); > > + > > + host = mmc_priv(mmc); > > + host->mmc = mmc; > > + > > + /* Initialize clock source */ > > + clk = devm_clk_get(dev, NULL); > > + if (IS_ERR(clk)) > > + return dev_err_probe(dev, PTR_ERR(clk), "can't get clock\n"); > > + host->ref_clk = clk_get_rate(clk); > > + host->sd_clk = 0; > > + > > + /* > > + * LiteSDCard only supports 4-bit bus width; therefore, we MUST inject > > + * a SET_BUS_WIDTH (acmd6) before the very first data transfer, earlier > > + * than when the mmc subsystem would normally get around to it! > > + */ > > + host->is_bus_width_set = false; > > + host->app_cmd = false; > > + > > + /* LiteSDCard can support 64-bit DMA addressing */ > > + ret = dma_set_mask_and_coherent(dev, DMA_BIT_MASK(64)); > > + if (ret) > > + return ret; > > + > > + host->buf_size = mmc->max_req_size * 2; > > + host->buffer = dmam_alloc_coherent(dev, host->buf_size, > > + &host->dma, GFP_KERNEL); > > + if (host->buffer == NULL) > > + return -ENOMEM; > > + > > + host->sdphy = devm_platform_ioremap_resource_byname(pdev, "phy"); > > + if (IS_ERR(host->sdphy)) > > + return PTR_ERR(host->sdphy); > > + > > + host->sdcore = devm_platform_ioremap_resource_byname(pdev, "core"); > > + if (IS_ERR(host->sdcore)) > > + return PTR_ERR(host->sdcore); > > + > > + host->sdreader = devm_platform_ioremap_resource_byname(pdev, "reader"); > > + if (IS_ERR(host->sdreader)) > > + return PTR_ERR(host->sdreader); > > + > > + host->sdwriter = devm_platform_ioremap_resource_byname(pdev, "writer"); > > + if (IS_ERR(host->sdwriter)) > > + return PTR_ERR(host->sdwriter); > > + > > + /* Ensure DMA bus masters are disabled */ > > + litex_write8(host->sdreader + LITEX_BLK2MEM_ENA, 0); > > + litex_write8(host->sdwriter + LITEX_MEM2BLK_ENA, 0); > > + > > + init_completion(&host->cmd_done); > > + ret = litex_mmc_irq_init(pdev, host); > > + if (ret) > > + return ret; > > + > > + /* Allow full generic 2.7-3.6V range; no software tuning available */ > > + mmc->ocr_avail = LITEX_MMC_OCR; > > + > > + mmc->ops = &litex_mmc_ops; > > + > > + /* > > + * Set default sd_clk frequency range based on empirical observations > > + * of LiteSDCard gateware behavior on typical SDCard media > > + */ > > + mmc->f_min = 12.5e6; > > + mmc->f_max = 50e6; > > + > > + ret = mmc_of_parse(mmc); > > + if (ret) > > + return ret; > > + > > + /* Force 4-bit bus_width (only width supported by hardware) */ > > + mmc->caps &= ~MMC_CAP_8_BIT_DATA; > > + mmc->caps |= MMC_CAP_4_BIT_DATA; > > + > > + /* Set default capabilities */ > > + mmc->caps |= MMC_CAP_WAIT_WHILE_BUSY | > > + MMC_CAP_DRIVER_TYPE_D | > > + MMC_CAP_CMD23; > > + mmc->caps2 |= MMC_CAP2_NO_WRITE_PROTECT | > > + MMC_CAP2_NO_SDIO | > > + MMC_CAP2_NO_MMC; > > + > > + platform_set_drvdata(pdev, host); > > One more thing here. Or somewhere, should we add: > > dev_info(dev, "Litex MMC controller initialized"); > > I was having a hard time debugging probing of this and having no printk's made > it a bit difficult. > > Though I was able to get most of the debug statements I needed using: > > "debug initcall_debug dyndbg=\"file drivers/* +p\" loglevel=8" > > -Stafford > > > + return mmc_add_host(mmc); I'd prefer to declare victory *after* calling mmc_add_host(), so if there are no objections I'd prefer to do the following in v12: ... platform_set_drvdata(pdev, host); - return mmc_add_host(mmc); + ret = mmc_add_host(mmc); + if (ret) + return dev_err_probe(dev, ret, "LiteX MMC probe failed!\n"); + + dev_info(dev, "LiteX MMC controller initialized.\n"); + + return 0; } Thanks, --Gabriel
diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig index 5af8494c31b5..8f661f52b502 100644 --- a/drivers/mmc/host/Kconfig +++ b/drivers/mmc/host/Kconfig @@ -1093,3 +1093,12 @@ config MMC_OWL config MMC_SDHCI_EXTERNAL_DMA bool + +config MMC_LITEX + tristate "LiteX MMC Host Controller support" + depends on ((PPC_MICROWATT || LITEX) && OF) || COMPILE_TEST + help + This selects support for the MMC Host Controller found in LiteX SoCs. + + To compile this driver as a module, choose M here: the + module will be called litex_mmc. diff --git a/drivers/mmc/host/Makefile b/drivers/mmc/host/Makefile index ea36d379bd3c..4e4ceb32c4b4 100644 --- a/drivers/mmc/host/Makefile +++ b/drivers/mmc/host/Makefile @@ -101,6 +101,7 @@ obj-$(CONFIG_MMC_CQHCI) += cqhci.o cqhci-y += cqhci-core.o cqhci-$(CONFIG_MMC_CRYPTO) += cqhci-crypto.o obj-$(CONFIG_MMC_HSQ) += mmc_hsq.o +obj-$(CONFIG_MMC_LITEX) += litex_mmc.o ifeq ($(CONFIG_CB710_DEBUG),y) CFLAGS-cb710-mmc += -DDEBUG diff --git a/drivers/mmc/host/litex_mmc.c b/drivers/mmc/host/litex_mmc.c new file mode 100644 index 000000000000..cc2848030e6b --- /dev/null +++ b/drivers/mmc/host/litex_mmc.c @@ -0,0 +1,657 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * LiteX LiteSDCard driver + * + * Copyright (C) 2019-2020 Antmicro <contact@antmicro.com> + * Copyright (C) 2019-2020 Kamil Rakoczy <krakoczy@antmicro.com> + * Copyright (C) 2019-2020 Maciej Dudek <mdudek@internships.antmicro.com> + * Copyright (C) 2020 Paul Mackerras <paulus@ozlabs.org> + * Copyright (C) 2020-2022 Gabriel Somlo <gsomlo@gmail.com> + */ + +#include <linux/bits.h> +#include <linux/clk.h> +#include <linux/delay.h> +#include <linux/dma-mapping.h> +#include <linux/interrupt.h> +#include <linux/iopoll.h> +#include <linux/litex.h> +#include <linux/mod_devicetable.h> +#include <linux/module.h> +#include <linux/platform_device.h> + +#include <linux/mmc/host.h> +#include <linux/mmc/mmc.h> +#include <linux/mmc/sd.h> + +#define LITEX_PHY_CARDDETECT 0x00 +#define LITEX_PHY_CLOCKERDIV 0x04 +#define LITEX_PHY_INITIALIZE 0x08 +#define LITEX_PHY_WRITESTATUS 0x0C +#define LITEX_CORE_CMDARG 0x00 +#define LITEX_CORE_CMDCMD 0x04 +#define LITEX_CORE_CMDSND 0x08 +#define LITEX_CORE_CMDRSP 0x0C +#define LITEX_CORE_CMDEVT 0x1C +#define LITEX_CORE_DATEVT 0x20 +#define LITEX_CORE_BLKLEN 0x24 +#define LITEX_CORE_BLKCNT 0x28 +#define LITEX_BLK2MEM_BASE 0x00 +#define LITEX_BLK2MEM_LEN 0x08 +#define LITEX_BLK2MEM_ENA 0x0C +#define LITEX_BLK2MEM_DONE 0x10 +#define LITEX_BLK2MEM_LOOP 0x14 +#define LITEX_MEM2BLK_BASE 0x00 +#define LITEX_MEM2BLK_LEN 0x08 +#define LITEX_MEM2BLK_ENA 0x0C +#define LITEX_MEM2BLK_DONE 0x10 +#define LITEX_MEM2BLK_LOOP 0x14 +#define LITEX_MEM2BLK 0x18 +#define LITEX_IRQ_STATUS 0x00 +#define LITEX_IRQ_PENDING 0x04 +#define LITEX_IRQ_ENABLE 0x08 + +#define SD_CTL_DATA_XFER_NONE 0 +#define SD_CTL_DATA_XFER_READ 1 +#define SD_CTL_DATA_XFER_WRITE 2 + +#define SD_CTL_RESP_NONE 0 +#define SD_CTL_RESP_SHORT 1 +#define SD_CTL_RESP_LONG 2 +#define SD_CTL_RESP_SHORT_BUSY 3 + +#define SD_BIT_DONE BIT(0) +#define SD_BIT_WR_ERR BIT(1) +#define SD_BIT_TIMEOUT BIT(2) +#define SD_BIT_CRC_ERR BIT(3) + +#define SD_SLEEP_US 5 +#define SD_TIMEOUT_US 20000 + +#define SDIRQ_CARD_DETECT 1 +#define SDIRQ_SD_TO_MEM_DONE 2 +#define SDIRQ_MEM_TO_SD_DONE 4 +#define SDIRQ_CMD_DONE 8 + +#define LITEX_MMC_OCR (MMC_VDD_27_28 | MMC_VDD_28_29 | MMC_VDD_29_30 | \ + MMC_VDD_30_31 | MMC_VDD_31_32 | MMC_VDD_32_33 | \ + MMC_VDD_33_34 | MMC_VDD_34_35 | MMC_VDD_35_36) + +struct litex_mmc_host { + struct mmc_host *mmc; + + void __iomem *sdphy; + void __iomem *sdcore; + void __iomem *sdreader; + void __iomem *sdwriter; + void __iomem *sdirq; + + void *buffer; + size_t buf_size; + dma_addr_t dma; + + struct completion cmd_done; + int irq; + + unsigned int ref_clk; + unsigned int sd_clk; + + u32 resp[4]; + u16 rca; + + bool is_bus_width_set; + bool app_cmd; +}; + +static int litex_mmc_sdcard_wait_done(void __iomem *reg, struct device *dev) +{ + u8 evt; + int ret; + + ret = readx_poll_timeout(litex_read8, reg, evt, evt & SD_BIT_DONE, + SD_SLEEP_US, SD_TIMEOUT_US); + if (ret) + return ret; + if (evt == SD_BIT_DONE) + return 0; + if (evt & SD_BIT_WR_ERR) + return -EIO; + if (evt & SD_BIT_TIMEOUT) + return -ETIMEDOUT; + if (evt & SD_BIT_CRC_ERR) + return -EILSEQ; + dev_err(dev, "%s: unknown error (evt=%x)\n", __func__, evt); + return -EINVAL; +} + +static int litex_mmc_send_cmd(struct litex_mmc_host *host, + u8 cmd, u32 arg, u8 response_len, u8 transfer) +{ + struct device *dev = mmc_dev(host->mmc); + void __iomem *reg; + int ret; + u8 evt; + + litex_write32(host->sdcore + LITEX_CORE_CMDARG, arg); + litex_write32(host->sdcore + LITEX_CORE_CMDCMD, + cmd << 8 | transfer << 5 | response_len); + litex_write8(host->sdcore + LITEX_CORE_CMDSND, 1); + + /* + * Wait for an interrupt if we have an interrupt and either there is + * data to be transferred, or if the card can report busy via DAT0. + */ + if (host->irq > 0 && + (transfer != SD_CTL_DATA_XFER_NONE || + response_len == SD_CTL_RESP_SHORT_BUSY)) { + reinit_completion(&host->cmd_done); + litex_write32(host->sdirq + LITEX_IRQ_ENABLE, + SDIRQ_CMD_DONE | SDIRQ_CARD_DETECT); + wait_for_completion(&host->cmd_done); + } + + ret = litex_mmc_sdcard_wait_done(host->sdcore + LITEX_CORE_CMDEVT, dev); + if (ret) { + dev_err(dev, "Command (cmd %d) error, status %d\n", cmd, ret); + return ret; + } + + if (response_len != SD_CTL_RESP_NONE) { + /* + * NOTE: this matches the semantics of litex_read32() + * regardless of underlying arch endianness! + */ + memcpy_fromio(host->resp, + host->sdcore + LITEX_CORE_CMDRSP, 0x10); + } + + if (!host->app_cmd && cmd == SD_SEND_RELATIVE_ADDR) + host->rca = (host->resp[3] >> 16); + + host->app_cmd = (cmd == MMC_APP_CMD); + + if (transfer == SD_CTL_DATA_XFER_NONE) + return ret; /* OK from prior litex_mmc_sdcard_wait_done() */ + + ret = litex_mmc_sdcard_wait_done(host->sdcore + LITEX_CORE_DATEVT, dev); + if (ret) { + dev_err(dev, "Data xfer (cmd %d) error, status %d\n", cmd, ret); + return ret; + } + + /* Wait for completion of (read or write) DMA transfer */ + reg = (transfer == SD_CTL_DATA_XFER_READ) ? + host->sdreader + LITEX_BLK2MEM_DONE : + host->sdwriter + LITEX_MEM2BLK_DONE; + ret = readx_poll_timeout(litex_read8, reg, evt, evt & SD_BIT_DONE, + SD_SLEEP_US, SD_TIMEOUT_US); + if (ret) + dev_err(dev, "DMA timeout (cmd %d)\n", cmd); + + return ret; +} + +static int litex_mmc_send_app_cmd(struct litex_mmc_host *host) +{ + return litex_mmc_send_cmd(host, MMC_APP_CMD, host->rca << 16, + SD_CTL_RESP_SHORT, SD_CTL_DATA_XFER_NONE); +} + +static int litex_mmc_send_set_bus_w_cmd(struct litex_mmc_host *host, u32 width) +{ + return litex_mmc_send_cmd(host, SD_APP_SET_BUS_WIDTH, width, + SD_CTL_RESP_SHORT, SD_CTL_DATA_XFER_NONE); +} + +static int litex_mmc_set_bus_width(struct litex_mmc_host *host) +{ + bool app_cmd_sent; + int ret; + + if (host->is_bus_width_set) + return 0; + + /* Ensure 'app_cmd' precedes 'app_set_bus_width_cmd' */ + app_cmd_sent = host->app_cmd; /* was preceding command app_cmd? */ + if (!app_cmd_sent) { + ret = litex_mmc_send_app_cmd(host); + if (ret) + return ret; + } + + /* LiteSDCard only supports 4-bit bus width */ + ret = litex_mmc_send_set_bus_w_cmd(host, MMC_BUS_WIDTH_4); + if (ret) + return ret; + + /* Re-send 'app_cmd' if necessary */ + if (app_cmd_sent) { + ret = litex_mmc_send_app_cmd(host); + if (ret) + return ret; + } + + host->is_bus_width_set = true; + + return 0; +} + +static int litex_mmc_get_cd(struct mmc_host *mmc) +{ + struct litex_mmc_host *host = mmc_priv(mmc); + int ret; + + if (!mmc_card_is_removable(mmc)) + return 1; + + ret = !litex_read8(host->sdphy + LITEX_PHY_CARDDETECT); + if (ret) + return ret; + + /* Ensure bus width will be set (again) upon card (re)insertion */ + host->is_bus_width_set = false; + + return 0; +} + +static irqreturn_t litex_mmc_interrupt(int irq, void *arg) +{ + struct mmc_host *mmc = arg; + struct litex_mmc_host *host = mmc_priv(mmc); + u32 pending = litex_read32(host->sdirq + LITEX_IRQ_PENDING); + irqreturn_t ret = IRQ_NONE; + + /* Check for card change interrupt */ + if (pending & SDIRQ_CARD_DETECT) { + litex_write32(host->sdirq + LITEX_IRQ_PENDING, + SDIRQ_CARD_DETECT); + mmc_detect_change(mmc, msecs_to_jiffies(10)); + ret = IRQ_HANDLED; + } + + /* Check for command completed */ + if (pending & SDIRQ_CMD_DONE) { + /* Disable it so it doesn't keep interrupting */ + litex_write32(host->sdirq + LITEX_IRQ_ENABLE, + SDIRQ_CARD_DETECT); + complete(&host->cmd_done); + ret = IRQ_HANDLED; + } + + return ret; +} + +static u32 litex_mmc_response_len(struct mmc_command *cmd) +{ + if (cmd->flags & MMC_RSP_136) + return SD_CTL_RESP_LONG; + if (!(cmd->flags & MMC_RSP_PRESENT)) + return SD_CTL_RESP_NONE; + if (cmd->flags & MMC_RSP_BUSY) + return SD_CTL_RESP_SHORT_BUSY; + return SD_CTL_RESP_SHORT; +} + +static void litex_mmc_do_dma(struct litex_mmc_host *host, struct mmc_data *data, + unsigned int *len, bool *direct, u8 *transfer) +{ + struct device *dev = mmc_dev(host->mmc); + dma_addr_t dma; + int sg_count; + + /* + * Try to DMA directly to/from the data buffer. + * We can do that if the buffer can be mapped for DMA + * in one contiguous chunk. + */ + dma = host->dma; + *len = data->blksz * data->blocks; + sg_count = dma_map_sg(dev, data->sg, data->sg_len, + mmc_get_dma_dir(data)); + if (sg_count == 1) { + dma = sg_dma_address(data->sg); + *len = sg_dma_len(data->sg); + *direct = true; + } else if (*len > host->buf_size) + *len = host->buf_size; + + if (data->flags & MMC_DATA_READ) { + litex_write8(host->sdreader + LITEX_BLK2MEM_ENA, 0); + litex_write64(host->sdreader + LITEX_BLK2MEM_BASE, dma); + litex_write32(host->sdreader + LITEX_BLK2MEM_LEN, *len); + litex_write8(host->sdreader + LITEX_BLK2MEM_ENA, 1); + *transfer = SD_CTL_DATA_XFER_READ; + } else if (data->flags & MMC_DATA_WRITE) { + if (!*direct) + sg_copy_to_buffer(data->sg, data->sg_len, + host->buffer, *len); + litex_write8(host->sdwriter + LITEX_MEM2BLK_ENA, 0); + litex_write64(host->sdwriter + LITEX_MEM2BLK_BASE, dma); + litex_write32(host->sdwriter + LITEX_MEM2BLK_LEN, *len); + litex_write8(host->sdwriter + LITEX_MEM2BLK_ENA, 1); + *transfer = SD_CTL_DATA_XFER_WRITE; + } else { + dev_warn(dev, "Data present w/o read or write flag.\n"); + /* Continue: set cmd status, mark req done */ + } + + litex_write16(host->sdcore + LITEX_CORE_BLKLEN, data->blksz); + litex_write32(host->sdcore + LITEX_CORE_BLKCNT, data->blocks); +} + +static void litex_mmc_request(struct mmc_host *mmc, struct mmc_request *mrq) +{ + struct litex_mmc_host *host = mmc_priv(mmc); + struct device *dev = mmc_dev(mmc); + struct mmc_command *cmd = mrq->cmd; + struct mmc_command *sbc = mrq->sbc; + struct mmc_data *data = mrq->data; + struct mmc_command *stop = mrq->stop; + unsigned int retries = cmd->retries; + unsigned int len = 0; + bool direct = false; + u32 response_len = litex_mmc_response_len(cmd); + u8 transfer = SD_CTL_DATA_XFER_NONE; + + /* First check that the card is still there */ + if (!litex_mmc_get_cd(mmc)) { + cmd->error = -ENOMEDIUM; + mmc_request_done(mmc, mrq); + return; + } + + /* Send set-block-count command if needed */ + if (sbc) { + sbc->error = litex_mmc_send_cmd(host, sbc->opcode, sbc->arg, + litex_mmc_response_len(sbc), + SD_CTL_DATA_XFER_NONE); + if (sbc->error) { + host->is_bus_width_set = false; + mmc_request_done(mmc, mrq); + return; + } + } + + if (data) { + /* + * LiteSDCard only supports 4-bit bus width; therefore, we MUST + * inject a SET_BUS_WIDTH (acmd6) before the very first data + * transfer, earlier than when the mmc subsystem would normally + * get around to it! + */ + cmd->error = litex_mmc_set_bus_width(host); + if (cmd->error) { + dev_err(dev, "Can't set bus width!\n"); + mmc_request_done(mmc, mrq); + return; + } + + litex_mmc_do_dma(host, data, &len, &direct, &transfer); + } + + do { + cmd->error = litex_mmc_send_cmd(host, cmd->opcode, cmd->arg, + response_len, transfer); + } while (cmd->error && retries-- > 0); + + if (cmd->error) { + /* Card may be gone; don't assume bus width is still set */ + host->is_bus_width_set = false; + } + + if (response_len == SD_CTL_RESP_SHORT) { + /* Pull short response fields from appropriate host registers */ + cmd->resp[0] = host->resp[3]; + cmd->resp[1] = host->resp[2] & 0xFF; + } else if (response_len == SD_CTL_RESP_LONG) { + cmd->resp[0] = host->resp[0]; + cmd->resp[1] = host->resp[1]; + cmd->resp[2] = host->resp[2]; + cmd->resp[3] = host->resp[3]; + } + + /* Send stop-transmission command if required */ + if (stop && (cmd->error || !sbc)) { + stop->error = litex_mmc_send_cmd(host, stop->opcode, stop->arg, + litex_mmc_response_len(stop), + SD_CTL_DATA_XFER_NONE); + if (stop->error) + host->is_bus_width_set = false; + } + + if (data) { + dma_unmap_sg(dev, data->sg, data->sg_len, + mmc_get_dma_dir(data)); + } + + if (!cmd->error && transfer != SD_CTL_DATA_XFER_NONE) { + data->bytes_xfered = min(len, mmc->max_req_size); + if (transfer == SD_CTL_DATA_XFER_READ && !direct) { + sg_copy_from_buffer(data->sg, sg_nents(data->sg), + host->buffer, data->bytes_xfered); + } + } + + mmc_request_done(mmc, mrq); +} + +static void litex_mmc_setclk(struct litex_mmc_host *host, unsigned int freq) +{ + struct device *dev = mmc_dev(host->mmc); + u32 div; + + div = freq ? host->ref_clk / freq : 256U; + div = roundup_pow_of_two(div); + div = clamp(div, 2U, 256U); + dev_dbg(dev, "sd_clk_freq=%d: set to %d via div=%d\n", + freq, host->ref_clk / div, div); + litex_write16(host->sdphy + LITEX_PHY_CLOCKERDIV, div); + host->sd_clk = freq; +} + +static void litex_mmc_set_ios(struct mmc_host *mmc, struct mmc_ios *ios) +{ + struct litex_mmc_host *host = mmc_priv(mmc); + + /* + * NOTE: Ignore any ios->bus_width updates; they occur right after + * the mmc core sends its own acmd6 bus-width change notification, + * which is redundant since we snoop on the command flow and inject + * an early acmd6 before the first data transfer command is sent! + */ + + /* Update sd_clk */ + if (ios->clock != host->sd_clk) + litex_mmc_setclk(host, ios->clock); +} + +static const struct mmc_host_ops litex_mmc_ops = { + .get_cd = litex_mmc_get_cd, + .request = litex_mmc_request, + .set_ios = litex_mmc_set_ios, +}; + +static int litex_mmc_irq_init(struct platform_device *pdev, + struct litex_mmc_host *host) +{ + struct device *dev = mmc_dev(host->mmc); + int ret; + + ret = platform_get_irq_optional(pdev, 0); + if (ret < 0 && ret != -ENXIO) + return ret; + if (ret > 0) + host->irq = ret; + else { + dev_warn(dev, "Failed to get IRQ, using polling\n"); + goto use_polling; + } + + host->sdirq = devm_platform_ioremap_resource_byname(pdev, "irq"); + if (IS_ERR(host->sdirq)) + return PTR_ERR(host->sdirq); + + ret = devm_request_irq(dev, host->irq, litex_mmc_interrupt, 0, + "litex-mmc", host->mmc); + if (ret < 0) { + dev_warn(dev, "IRQ request error %d, using polling\n", ret); + goto use_polling; + } + + /* Clear & enable card-change interrupts */ + litex_write32(host->sdirq + LITEX_IRQ_PENDING, SDIRQ_CARD_DETECT); + litex_write32(host->sdirq + LITEX_IRQ_ENABLE, SDIRQ_CARD_DETECT); + + return 0; + +use_polling: + host->mmc->caps |= MMC_CAP_NEEDS_POLL; + return 0; +} + +static void litex_mmc_free_host_wrapper(void *mmc) +{ + mmc_free_host(mmc); +} + +static int litex_mmc_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct litex_mmc_host *host; + struct mmc_host *mmc; + struct clk *clk; + int ret; + + /* + * NOTE: defaults to max_[req,seg]_size=PAGE_SIZE, max_blk_size=512, + * and max_blk_count accordingly set to 8; + * If for some reason we need to modify max_blk_count, we must also + * re-calculate `max_[req,seg]_size = max_blk_size * max_blk_count;` + */ + mmc = mmc_alloc_host(sizeof(struct litex_mmc_host), dev); + if (!mmc) + return -ENOMEM; + + ret = devm_add_action_or_reset(dev, litex_mmc_free_host_wrapper, mmc); + if (ret) + return dev_err_probe(dev, ret, + "Can't register mmc_free_host action\n"); + + host = mmc_priv(mmc); + host->mmc = mmc; + + /* Initialize clock source */ + clk = devm_clk_get(dev, NULL); + if (IS_ERR(clk)) + return dev_err_probe(dev, PTR_ERR(clk), "can't get clock\n"); + host->ref_clk = clk_get_rate(clk); + host->sd_clk = 0; + + /* + * LiteSDCard only supports 4-bit bus width; therefore, we MUST inject + * a SET_BUS_WIDTH (acmd6) before the very first data transfer, earlier + * than when the mmc subsystem would normally get around to it! + */ + host->is_bus_width_set = false; + host->app_cmd = false; + + /* LiteSDCard can support 64-bit DMA addressing */ + ret = dma_set_mask_and_coherent(dev, DMA_BIT_MASK(64)); + if (ret) + return ret; + + host->buf_size = mmc->max_req_size * 2; + host->buffer = dmam_alloc_coherent(dev, host->buf_size, + &host->dma, GFP_KERNEL); + if (host->buffer == NULL) + return -ENOMEM; + + host->sdphy = devm_platform_ioremap_resource_byname(pdev, "phy"); + if (IS_ERR(host->sdphy)) + return PTR_ERR(host->sdphy); + + host->sdcore = devm_platform_ioremap_resource_byname(pdev, "core"); + if (IS_ERR(host->sdcore)) + return PTR_ERR(host->sdcore); + + host->sdreader = devm_platform_ioremap_resource_byname(pdev, "reader"); + if (IS_ERR(host->sdreader)) + return PTR_ERR(host->sdreader); + + host->sdwriter = devm_platform_ioremap_resource_byname(pdev, "writer"); + if (IS_ERR(host->sdwriter)) + return PTR_ERR(host->sdwriter); + + /* Ensure DMA bus masters are disabled */ + litex_write8(host->sdreader + LITEX_BLK2MEM_ENA, 0); + litex_write8(host->sdwriter + LITEX_MEM2BLK_ENA, 0); + + init_completion(&host->cmd_done); + ret = litex_mmc_irq_init(pdev, host); + if (ret) + return ret; + + /* Allow full generic 2.7-3.6V range; no software tuning available */ + mmc->ocr_avail = LITEX_MMC_OCR; + + mmc->ops = &litex_mmc_ops; + + /* + * Set default sd_clk frequency range based on empirical observations + * of LiteSDCard gateware behavior on typical SDCard media + */ + mmc->f_min = 12.5e6; + mmc->f_max = 50e6; + + ret = mmc_of_parse(mmc); + if (ret) + return ret; + + /* Force 4-bit bus_width (only width supported by hardware) */ + mmc->caps &= ~MMC_CAP_8_BIT_DATA; + mmc->caps |= MMC_CAP_4_BIT_DATA; + + /* Set default capabilities */ + mmc->caps |= MMC_CAP_WAIT_WHILE_BUSY | + MMC_CAP_DRIVER_TYPE_D | + MMC_CAP_CMD23; + mmc->caps2 |= MMC_CAP2_NO_WRITE_PROTECT | + MMC_CAP2_NO_SDIO | + MMC_CAP2_NO_MMC; + + platform_set_drvdata(pdev, host); + + return mmc_add_host(mmc); +} + +static int litex_mmc_remove(struct platform_device *pdev) +{ + struct litex_mmc_host *host = platform_get_drvdata(pdev); + + mmc_remove_host(host->mmc); + return 0; +} + +static const struct of_device_id litex_match[] = { + { .compatible = "litex,mmc" }, + { } +}; +MODULE_DEVICE_TABLE(of, litex_match); + +static struct platform_driver litex_mmc_driver = { + .probe = litex_mmc_probe, + .remove = litex_mmc_remove, + .driver = { + .name = "litex-mmc", + .of_match_table = litex_match, + }, +}; +module_platform_driver(litex_mmc_driver); + +MODULE_DESCRIPTION("LiteX SDCard driver"); +MODULE_AUTHOR("Antmicro <contact@antmicro.com>"); +MODULE_AUTHOR("Kamil Rakoczy <krakoczy@antmicro.com>"); +MODULE_AUTHOR("Maciej Dudek <mdudek@internships.antmicro.com>"); +MODULE_AUTHOR("Paul Mackerras <paulus@ozlabs.org>"); +MODULE_AUTHOR("Gabriel Somlo <gsomlo@gmail.com>"); +MODULE_LICENSE("GPL v2");