[PATCH V4 1/4] mmc: core: Initial support for MMC power sequences
From: javier@dowhile0.org (Javier Martinez Canillas)
Date: 2015-01-28 10:17:22
Also in:
linux-devicetree, linux-mmc
Hello Ulf, On Mon, Jan 19, 2015 at 10:13 AM, Ulf Hansson [off-list ref] wrote:
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 sequence. 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 CONFIG_OF. Signed-off-by: Ulf Hansson <redacted> ---
Patch looks good to me and I could successfully get the SDIO wlan chip in the Snow Chromebook after extending the pwrseq_simple driver so on Exynos5250 Snow Chromebook: Tested-by: Javier Martinez Canillas <redacted> Reviewed-by: Javier Martinez Canillas <redacted> Best regards, Javier