Re: [PATCH] ACPI / PMIC: xpower: Do pinswitch magic when reading GPADC

[Hans de Goede <hdegoede@redhat.com>]

Hi,

On 08-07-17 15:58, Andy Shevchenko wrote:
> On Sat, 2017-07-08 at 15:40 +0200, Hans de Goede wrote:
>> Testing has shown that the TS-pin's bias-current needs to be disabled
>> when reading the GPIO0 pin in GPADC mode.
>>
>> It seems that there is only 1 bias current source and to be able to
>> use it
>> for the GPIO0 pin in GPADC mode it must be temporarily turned off for
>> the
>> TS pin, but the datasheet does not mention this.
>>
>> This commit adds the necessary writes to turn the TS pin BIAS current
>> off before and back on after reading the GPADC. This fixes the GPADC
>> always returning a reading of 0.
>>
>>
> 
>> +	/* After switching to the GPADC pin give things some time to
>> settle */
>> +	usleep_range(6000, 10000);
> 
> msleep(6); ?

That will make checkpatch unhappy and may sleep for as long as 20ms, also see:
Documentation/timers/timers-howto.txt which advices against using msleep for
short sleeps.

Regards,

Hans