On 19 January 2015 at 10:13, Ulf Hansson <ulf.hansson@xxxxxxxxxx> wrote: > Changes in v4: > - Fixed call to kfree() in patch3 and patch4. > > Changes in v3: > Fixed comments from Mark Rutland: > - Document binding in one patch to get the big picture. > - Keep code and DT document consistent around how many GPIO resets we > support. I decided to go for one GPIO, we can extend that if needed > later on. > - Change compatible string for simple MMC power sequence and renamed the > file for its documentation. > - Updated commit messages according to above changes. > > Changes in v2: > Fixed comments from Russell King: > - Renamed pwrseq callbacks and corresponding interface functions. > - Move the call to the previous namned ->power_on() callback, to the > end of mmc_power_up() to get consistent behavior. > > > This is yet another try to solve the issues of dealing with power sequences for > the MMC subsystem. The latest attempt, see link below, took a generic approach > by adding a new top level driver layer. That's was rejected by several reasons. > http://lwn.net/Articles/602855/ > > This time the approach is focused to fix the issues for MMC only. > > To give a short background, SOCs may specify a specific MMC power sequence. To > successfully detect an (e)MMC/SD/SDIO card, that power sequence must be followed > while initializing the card. > > To be able to handle these SOC specific power sequences, we add a MMC power > sequence interface, which helps the mmc core to deal with such. > > A MMC power sequence provider then implements a set of callbacks from the above > mentioned interface. The provider has a corresponding DT compatibility string > and relies on CONFIG_OF to be set to find it's various resourses, like for > example a GPIO reset. > > The mmc core will from mmc_of_parse() try find a "mmc-pwrseq" DT node and then > call the corresponding MMC power sequence provider's initialization function. > > > Ulf Hansson (4): > mmc: core: Initial support for MMC power sequences > mmc: pwrseq: Document DT bindings for the simple MMC power sequence > mmc: pwrseq: Initial support for the simple MMC power sequence > provider > mmc: pwrseq_simple: Add support for a reset GPIO pin > > .../devicetree/bindings/mmc/mmc-pwrseq-simple.txt | 20 ++++ > Documentation/devicetree/bindings/mmc/mmc.txt | 14 +++ > drivers/mmc/core/Makefile | 2 +- > drivers/mmc/core/core.c | 7 ++ > drivers/mmc/core/host.c | 4 +- > drivers/mmc/core/pwrseq.c | 109 +++++++++++++++++++++ > drivers/mmc/core/pwrseq.h | 42 ++++++++ > drivers/mmc/core/pwrseq_simple.c | 86 ++++++++++++++++ > include/linux/mmc/host.h | 2 + > 9 files changed, 284 insertions(+), 2 deletions(-) > create mode 100644 Documentation/devicetree/bindings/mmc/mmc-pwrseq-simple.txt > create mode 100644 drivers/mmc/core/pwrseq.c > create mode 100644 drivers/mmc/core/pwrseq.h > create mode 100644 drivers/mmc/core/pwrseq_simple.c > > -- > 1.9.1 > To get some more testing of this code, I have now applied this v4 of this patchset for my next branch. Kind regards Uffe -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
