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 | 23 +++++ Documentation/devicetree/bindings/mmc/mmc.txt | 5 + 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, 278 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 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
