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@xxxxxxxxxxxx> > Signed-off-by: Kamil Rakoczy <krakoczy@xxxxxxxxxxxx> > Co-developed-by: Maciej Dudek <mdudek@xxxxxxxxxxxxxxxxxxxxxxxx> > Signed-off-by: Maciej Dudek <mdudek@xxxxxxxxxxxxxxxxxxxxxxxx> > Co-developed-by: Paul Mackerras <paulus@xxxxxxxxxx> > Signed-off-by: Paul Mackerras <paulus@xxxxxxxxxx> > Signed-off-by: Gabriel Somlo <gsomlo@xxxxxxxxx> > Reviewed-by: Joel Stanley <joel@xxxxxxxxx> > Reviewed-by: Andy Shevchenko <andy.shevchenko@xxxxxxxxx> > --- > > 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
