On Sat 28 Mar 2020 at 01:32, Martin Blumenstingl <martin.blumenstingl@xxxxxxxxxxxxxx> wrote: > Hello, > > this is the patchset for a driver for the Amlogic "SDHC" MMC controller > found on Meson6, Meson8, Meson8b and Meson8m2 SoCs. > > The public S805 (Meson8b) datasheet has some documentation starting on > page 74: [0] > > It's performance is still not as good as the driver from Amlogic's 3.10 > kernel, but it does not corrupt data anymore (as RFC v1 did). > > Special thanks to the people who supported me off-list - you are > amazing and deserve to be mentioned here: > - Xin Yin who helped me fix two more write corruption problems. I am > hoping that he will reply with Reviewed-by, Tested-by and Bug-fixed-by > - Jianxin Pan for sharing some of the internal workings of this MMC > controller with me > - Wei Wang for spotting the initial write corruption problem and helping > test this driver on his board. I have his permission to add his > Tested-by (off-list, he's Cc'ed so if there's any problem he can speak > up) > > > Changes since v4 at [4]: > - move the four clkin clock inputs to the start of the clock-names list > as suggested by Rob, affects patch #1 > - fixed #include statement in dt-bindings example in patch #1 > > Changes since v3 at [3]: > - split the clock bits into a separate clock controller driver because > of two reasons: 1) it keeps the MMC controller driver mostly clean of > the clock bits If the register is in the MMC controller register space and the MMC driver is the driver using these clocks, it is where the clocks belong. I don't get why it could be an issue ? Is the clock block is shared with another device, like on the Gx family ? > 2) the pure clock controller can use > devm_clk_hw_register() (instead of devm_clk_register(), which is > deprecated) and the MMC controller can act as a pure clock consumer. Why can't you use devm_clk_hw_register in an MMC driver ? Unless I missed something, it is provided by clk-provider.h, which can be included by any driver. I'm not sure I understand why the support for this device is split in two drivers. Using CCF clocks out of "drivers/clk" is encouraged. > This also affects the dt-bindings which is why I dropped Rob's > Reviewed-by. Thanks to Ulf for the suggestions > > Changes since v2 at [2]: > - rebased on top of v5.5-rc1 > - added Rob's and Xin Yin's Reviewed-by and Tested-by (thank you!) > - (note: Kevin had v2 of this series in -next for a few days so the > build test robots could play with it. I haven't received any negative > feedback in that time) > > Changes since RFC v1 at [1]: > - don't set MESON_SDHC_MISC_MANUAL_STOP to fix one of three write > corruption problems. the out-of-tree 3.10 "reference" driver doesn't > set it either > - check against data->flags instead of cmd->flags when testing for > MMC_DATA_WRITE as spotted by Xin Yin (many thanks!). This fixes > another write corruption problem > - clear the FIFOs after successfully transferring data as suggested by > Xin Yin (many thanks!). This is what the 3.10 driver did and fixes yet > another write corruption problem > - integrate the clock suggestions from Jianxin Pan so the driver is now > able to set up the clocks correctly for all known cases. documentation > is also added to the patch description. Thank you Jianxin for the > help! > - set the correct max_busy_timeout as suggested by Jianxin Pan (thanks!) > - convert the dt-bindings to .yaml (which is why I didn't add Rob's > Reviewed-by) > - switch to struct clk_parent_data as part of newer common clock > framework APIs to simplify the clock setup > - dropped CMD23 support because it seems to hurt read and write > performance by 10-20% in my tests. it's not clear why, but for now we > can live without this. > - use devm_platform_ioremap_resource instead of open-coding it > > > [0] https://dn.odroid.com/S805/Datasheet/S805_Datasheet%20V0.8%2020150126.pdf > [1] https://patchwork.kernel.org/cover/11035505/ > [2] http://lists.infradead.org/pipermail/linux-amlogic/2019-November/014576.html > [3] https://patchwork.kernel.org/cover/11283179/ > [4] https://patchwork.kernel.org/cover/11329017/ > > Martin Blumenstingl (3): > dt-bindings: mmc: Document the Amlogic Meson SDHC MMC host controller > clk: meson: add a driver for the Meson8/8b/8m2 SDHC clock controller > mmc: host: meson-mx-sdhc: new driver for the Amlogic Meson SDHC host > > .../bindings/mmc/amlogic,meson-mx-sdhc.yaml | 83 ++ > drivers/clk/meson/Kconfig | 9 + > drivers/clk/meson/Makefile | 1 + > drivers/clk/meson/meson-mx-sdhc.c | 212 ++++ > drivers/mmc/host/Kconfig | 14 + > drivers/mmc/host/Makefile | 1 + > drivers/mmc/host/meson-mx-sdhc.c | 1064 +++++++++++++++++ > .../dt-bindings/clock/meson-mx-sdhc-clkc.h | 8 + > 8 files changed, 1392 insertions(+) > create mode 100644 Documentation/devicetree/bindings/mmc/amlogic,meson-mx-sdhc.yaml > create mode 100644 drivers/clk/meson/meson-mx-sdhc.c > create mode 100644 drivers/mmc/host/meson-mx-sdhc.c > create mode 100644 include/dt-bindings/clock/meson-mx-sdhc-clkc.h
