• Ulf Hansson's avatar
    mmc: core: Initial support for MMC power sequences · 3aa8793f
    Ulf Hansson authored
    System on chip designs 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, let's add a
    MMC power sequence interface. It provides the following functions to
    help the mmc core to deal with these power sequences.
    mmc_pwrseq_alloc() - Invoked from mmc_of_parse(), to initialize data.
    mmc_pwrseq_pre_power_on()- Invoked in the beginning of mmc_power_up().
    mmc_pwrseq_post_power_on()- Invoked at the end in mmc_power_up().
    mmc_pwrseq_power_off()- Invoked from mmc_power_off().
    mmc_pwrseq_free() - Invoked from mmc_free_host(), to free data.
    Each MMC power sequence provider will be responsible to implement a set
    of callbacks. These callbacks mirrors the functions above.
    This patch adds the skeleton, following patches will extend the core of
    the MMC power sequence and add support for a specific simple MMC power
    Do note, since the mmc_pwrseq_alloc() is invoked from mmc_of_parse(),
    host drivers needs to make use of this API to enable the support for
    MMC power sequences. Moreover the MMC power sequence support depends on
    Signed-off-by: default avatarUlf Hansson <ulf.hansson@linaro.org>
    Tested-by: default avatarJavier Martinez Canillas <javier.martinez@collabora.co.uk>
    Reviewed-by: default avatarJavier Martinez Canillas <javier.martinez@collabora.co.uk>
core.c 65.9 KB