[v5 08/18] mmc: dwmmc: Change designware MMC 'clksel' callback function to return status

[Tan, Ley Foon]

> -----Original Message-----
> From: Lim, Elly Siew Chin <elly.siew.chin.lim at intel.com>
> Sent: Tuesday, December 22, 2020 12:50 AM
> To: u-boot at lists.denx.de
> Cc: Marek Vasut <marex at denx.de>; Tan, Ley Foon
> <ley.foon.tan at intel.com>; See, Chin Liang <chin.liang.see at intel.com>;
> Simon Goldschmidt <simon.k.r.goldschmidt at gmail.com>; Chee, Tien Fong
> <tien.fong.chee at intel.com>; Westergreen, Dalon
> <dalon.westergreen at intel.com>; Simon Glass <sjg at chromium.org>; Gan,
> Yau Wai <yau.wai.gan at intel.com>; Lim, Elly Siew Chin
> <elly.siew.chin.lim at intel.com>
> Subject: [v5 08/18] mmc: dwmmc: Change designware MMC 'clksel' callback
> function to return status
> 
> Change 'clksel' callback function to allow the code to return a status.
> 
> This patch is a preparation for enabling Arm-Trusted-Firmware (ATF) in Intel
> SoC FPGA. This patch does not change functionality.
> 
> When using Arm-Trusted-Firmware (ATF) in Intel SoC FPGA, the MMC clock
> related register is secure register which is required to be written via
> SMC/PCSI call. It is possible that U-Boot fail to write the register if there is
> unexpected error between U-Boot and ATF.
> As a result, there maybe signal integrity on MMC connection due to clock. So,
> the code should reports error to user when 'clksel' fail.
> 
> Signed-off-by: Siew Chin Lim <elly.siew.chin.lim at intel.com>
> ---

Reviewed-by: Ley Foon Tan <ley.foon.tan at intel.com>

Regards
Ley Foon