Re: [PATCH v5 2/3] clk: meson: add DT documentation for emmc clock controller

From: Jianxin Pan
Date: Sun Nov 04 2018 - 10:40:06 EST



Hi Stephen,

Thank you for the review.

On 2018/11/4 11:04, Stephen Boyd wrote:
> Quoting Yixun Lan (2018-10-25 00:29:15)
>> yes, I think the documentation need to be fixed
>>
>> for the final solution, we decide to make 'mmc-clkc' an independent node
>> instead of being a sub-node of 'mmc', so both of them may exist in parallel..
>>
>> the DT part may like this:
>>
>> sd_emmc_c_clkc: clock-controller@7000 {
>> compatible = "amlogic,axg-mmc-clkc", "syscon";
>> reg = <0x0 0x7000 0x0 0x4>;
>> ...
>> };
>>
>> sd_emmc_c: mmc@7000 {
>> compatible = "amlogic,axg-mmc";
>> reg = <0x0 0x7000 0x0 0x800>;
>> ...
>> };
>
> That's improper usage of DT. We don't want two devices at the same
> register offset.
sd_emmc_c_clkc is shared by nand and sd_emmc_c controller, and this clock is part of the MMC controller's register space.

The idea of adding the clock-controller@7000is introduced during the discussion in the NAND driver mainline effort:
https://lkml.kernel.org/r/20180628090034.0637a062@xps13
>
> .
>