Commit Graph

2 Commits

Author SHA1 Message Date
Alexandre Courbot 0f12a0ce4c mmc: pwrseq: simplify alloc/free hooks
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>
2015-03-23 14:13:42 +01:00
Marek Szyprowski 726b6324e3 mmc: pwrseq: add driver for emmc hardware reset
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>
2015-02-04 09:45:09 +01:00