[U-Boot] [PATCH] imx: mx6sxsabresd: support emmc

Stefano Babic
2016-01-24T11:07:14Z

Hi Peng,

On 23/12/2015 04:10, Peng Fan wrote:
> Hi Otavio,
> On Tue, Dec 22, 2015 at 09:51:37AM -0200, Otavio Salvador wrote:
>> On Tue, Dec 22, 2015 at 7:03 AM, Peng Fan <van.freenix@gmail.com> wrote:
>>> From: Peng Fan <peng.fan@nxp.com>
>>>
>>> For i.MX6SX SABRESD, USDHC4 can be used for SD and EMMC, default
>>> it is used for SD.
>>>
>>> This patch introduces EMMC pinmux settings and a new macro
>>> CONFIG_MX6SXSABRESD_EMMC_REWORK. If the board has been reworked
>>> to support emmc, need to enable this macro.
>>>
>>> Signed-off-by: Peng Fan <peng.fan@nxp.com>
>>> Cc: Stefano Babic <sbabic@denx.de>
>>
>> Is it worth supporting this 'reworked' board? if someone reworks a
>> board it is expected to have to rework the BSP of it, as well.
>
> usdhc4 can be used for SD and emmc. This is the feature of the board,
> so I think we need to support it. But there is no way to dynamically check
> whether using sd or emmc now, adding the macro for using emmc.

I agree with Otavio that this is a very nasty hack, and the hardware
developer should provide a way getting the board revision. Anyway, I
would not certainly block it, as it concerns just this board, but I ask
if it is not better to let decide to an environment variable if eMMC
must be activated. Advantage is to have a single U-Boot binary for both
boards, disadvantage is that it coul be set for the wrong board
revision, too. But if USDHC4 was not used anymore, this drives just to a
not found eMMC. Both ways are hacks, I fully agree, but
CONFIG_MX6SXSABRESD_EMMC_REWORK remains undocumented at all, too.

What do you think ?

Best regards,
Stefano Babic

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