mmc: dw_mmc: add reset support to dwmmc host controller

Dwmmc host controller may in unknown state when entering kernel boot. One
example is when booting from eMMC, bootloader need initialize MMC host
controller into some state so it can read. In order to make sure MMC host
controller in a clean initial state, this reset support is added.

With this patch, a 'resets' property can be added into dw_mmc device
tree node. The hardware logic is: dwmmc host controller IP receives a reset
signal from a 'reset provider' (eg. power management unit). The 'resets'
property points to this reset signal. So, during dwmmc driver probe,
it can use this signal to reset itself.

Refer to [1] for more information.

[1] Documentation/devicetree/bindings/reset/reset.txt

Signed-off-by: Guodong Xu <[email protected]>
Signed-off-by: Xinwei Kong <[email protected]>
Signed-off-by: Zhangfei Gao <[email protected]>
Reviewed-by: Shawn Lin <[email protected]>
Signed-off-by: Jaehoon Chung <[email protected]>
Signed-off-by: Ulf Hansson <[email protected]>

0 files changed, 0 insertions, 0 deletions