[linux-sunxi] Re: [PATCH 2/4] ARM: sunxi: Drop mmc0_cd_pin_reference_design pinmux setting

[Chen-Yu Tsai]

On Wed, Apr 19, 2017 at 11:36 PM,  <icenowy at aosc.io> wrote:
> 在 2017-04-19 13:09，Chen-Yu Tsai 写道：
>>
>> As part of our effort to move pinctrl/GPIO interlocking into the
>> driver where it belongs, this patch drops the definition and usage
>> of the mmc0_cd_pin_reference_design pinmux setting for the default
>> mmc0 card detect GPIO pin.
>>
>> Signed-off-by: Chen-Yu Tsai <wens at csie.org>

[...]

>> diff --git a/arch/arm/boot/dts/sun7i-a20.dtsi
>> b/arch/arm/boot/dts/sun7i-a20.dtsi
>> index 93aa55970bd7..c03b59aaec82 100644
>> --- a/arch/arm/boot/dts/sun7i-a20.dtsi
>> +++ b/arch/arm/boot/dts/sun7i-a20.dtsi
>> @@ -1190,12 +1190,6 @@
>>                                 bias-pull-up;
>>                         };
>>
>> -                       mmc0_cd_pin_reference_design: mmc0_cd_pin at 0 {
>> -                               pins = "PH1";
>> -                               function = "gpio_in";
>> -                               bias-pull-up;
>
>
> It needs pull up, so shouldn't be dropped.
>
> (Although there may be external pull-up resistors on the board;
> however last time we removed the pull-up on MMC node many boards
> failed, so we cannot rely on external pull-up resistors)

I checked the boards that I have schematics, and the reference design.
All have proper external pull-up resistors for this pin, unlike the
other mmc pins.

If some board doesn't, it really needs to be singled out and handled
separately. Have you encountered any issues?

Regards
ChenYu

>
>> -                       };
>> -
>>                         mmc2_pins_a: mmc2 at 0 {
>>                                 pins = "PC6", "PC7", "PC8",
>>                                        "PC9", "PC10", "PC11";
>
>
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