The pwrseq_emmc driver does a eMMC card reset before a system reboot to
allow broken or limited ROM boot-loaders (that don't have an eMMC reset
logic) to be able to read the second stage from the eMMC.
But this has to be called before a system reboot handler and while most
of them use the priority 128, there are other restart handlers (such as
the syscon-reboot one) that use a higher priority. So, use the highest
priority to make sure that the eMMC hw is reset before a system reboot.
Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com>
Tested-by: Markus Reichl <m.reichl@fivetechno.de>
Tested-by: Anand Moon <linux.amoon@gmail.com>
Reviewed-by: Alim Akhtar <alim.akhtar@samsung.com>
Tested-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
The gpiod_get() function expands to gpiod_get_index() with index 0
so it's better to use it since is easier to read and more concise.
Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
The alloc() and free() hooks required each pwrseq implementation to set
host->pwrseq themselves. This is error-prone and could be done at a
higher level if alloc() was changed to return a pointer to a struct
mmc_pwrseq instead of an error code.
This patch performs this change and moves the burden of maintaining
host->pwrseq from the power sequence hooks to the pwrseq code.
Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
This patch provides a simple mmc-pwrseq-emmc driver, which controls
single gpio line. It perform standard eMMC hw reset procedure, as
descibed by Jedec 4.4 specification. This procedure is performed just
after MMC core enabled power to the given mmc host (to fix possible
issues if bootloader has left eMMC card in initialized or unknown
state), and before performing complete system reboot (also in case of
emergency reboot call). The latter is needed on boards, which doesn't
have hardware reset logic connected to emmc card and (limited or broken)
ROM bootloaders are unable to read second stage from the emmc card if
the card is left in unknown or already initialized state.
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Javier Martinez Canillas