Hi Stefano,
On Sun, Jan 24, 2016 at 12:07:14PM +0100, Stefano Babic wrote:
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 ?
There is no fuse bit or else to let uboot do runtime checking. I also disklike this, but I do not have a better idea. Without runtime checking, it's hard to use one image support SD/EMMC both. I would like to add doc for the macro CONFIG_MX6SXSABRESD_EMMC_REWORK in the next version, do you agree with this?
Thanks, Peng.
Best regards, Stefano Babic
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