Re: [PATCH 06/15] ARM: dts: ipq4019: Add ipq4019-ap.dk04.dtsi

Sricharan R
2018-02-06T06:01:30Z

Hi Abhishek,

On 2/3/2018 4:47 PM, Abhishek Sahu wrote:
> On 2018-01-29 10:41, Sricharan R wrote:
>> Add the common parts for the dk04 boards.
>>
>> Signed-off-by: Sricharan R <sricharan@codeaurora.org>
>> ---
>>  arch/arm/boot/dts/qcom-ipq4019-ap.dk04.1.dtsi | 147
>
>  <snip>
>> +
>> +            nand_pins: nand_pins {
>> +                pullups {
>> +                    pins = "gpio52", "gpio53",
>> "gpio58",
>> +                        "gpio59";
>> +                    function = "qpic";
>> +                    bias-pull-up;
>> +                };
>> +
>> +                pulldowns {
>> +                    pins = "gpio54", "gpio55",
>> "gpio56",
>> +                        "gpio57", "gpio60",
>> "gpio61",
>> +                        "gpio62", "gpio63",
>> "gpio64",
>> +                        "gpio65", "gpio66",
>> "gpio67",
>> +                        "gpio68", "gpio69";
>> +                    function = "qpic";
>> +                    bias-pull-down;
>> +                };
>> +            };
>
>  Can you please check once why do we need pull-up and
>  pull-down for NAND pins. The NAND chip will be mounted
>  over board itself so board design should take care of
>  required pull up and pull downs.
>

Mostly because, these are always **weak** pull up/down as defaults
and should be overridden by the ones in the board (if there).

>  Also, some of the above pins like gpio52 will be only used
>  for LCD so we can remove those pins. Later on, when LCD
>  support will be added, we can add those pins.
ok

Regards,
Sricharan

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