Re: [PATCH] pinctrl: ingenic: Fix MMC pins for 4770/4780 SoCs

[Ezequiel Garcia <ezequiel@xxxxxxxxxxxxxxxxxxxx>]

On 4 March 2018 at 21:01, Paul Cercueil <paul@xxxxxxxxxxxxxxx> wrote:
> Hi,
>
> Le 2018-03-04 22:15, Ezequiel Garcia a écrit :
>>
>> This commit fixes the values for the pins and functions
>> of mmc0 and mmc1, for JZ4770 and JZ4780 SoCs.
>>
>> The bug was found on a Ci20 board, so changes are partially
>> tested on this board, in addition to careful verification
>> with the programming manual.
>>
>> Cc: Paul Cercueil <paul@xxxxxxxxxxxxxxx>
>> Signed-off-by: Ezequiel Garcia <ezequiel@xxxxxxxxxxxxxxxxxxxx>
>
>
> The current values were obviously tested and do work with the CI20 (jz4780)
> and the GCW0 (which has a jz4770).
>

Of course, maybe it's something else.

I've pushed a branch with MMC supported forwared-ported
to current mainline, in case you feel like giving a try.
It wasn't working for me, and this commit fixed it.

http://git.infradead.org/users/ezequielg/linux/shortlog/refs/heads/ci20-mmc-for-4.15

> Looking at the JZ4780 PM pdf, I don't think any of your values are correct.
>
> For instance, you set:
> static int jz4770_mmc0_1bit_a_pins[] = { 0x18, 0x19, 0x20, };
>
> This means pins GPA24, GPA25 and GPB0.

Doh, of course. My changes to the PA muxing are just bullshit.

> According to the manual, GPA24 is for
> MMC0 reset, but the other two are not in any way related to the MMC
> hardware.
>

Let's look a those that were actually tested. For instance:

>> -static int jz4770_mmc0_4bit_e_pins[] = { 0x95, 0x96, 0x97, };
>> +static int jz4770_mmc0_4bit_e_pins[] = { 0x94, 0x95, 0x96, 0x97, 0x9c,
>> 0x9d };

IIUC, the driver is muxing pins PE21, PE22 and PE23, which
belong to msc0_d1, msc0_d2 and msc0_d3.

According to my spec, it should mux PE20, PE21, PE22, PE23,
PE28 and PE29 (d0, d1, d2, d3, clk, cmd). Which is what my
patch is trying to do, if I did the math right.

I'm confused about the fact that a 4-bit mode muxes
just three pins, instead of six. So what am I missing here?

Thanks,
-- 
Ezequiel García, VanguardiaSur
www.vanguardiasur.com.ar
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