On Mon, Feb 26, 2018 at 5:01 AM, Baolin Wang <baolin.wang@xxxxxxxxxx> wrote:
> On 25 February 2018 at 20:19, Andy Shevchenko <andy.shevchenko@xxxxxxxxx> wrote:
>> On Sat, Feb 24, 2018 at 12:44 PM, Baolin Wang <baolin.wang@xxxxxxxxxx> wrote:
>>> +static int sprd_pmic_eic_direction_input(struct gpio_chip *chip,
>>> + unsigned int offset)
>>> +{
>>> + /* EICs are always input, nothing need to do here. */
>>> + return 0;
>>> +}
>>> +
>>> +static void sprd_pmic_eic_set(struct gpio_chip *chip, unsigned int offset,
>>> + int value)
>>> +{
>>> + /* EICs are always input, nothing need to do here. */
>>> +}
>>
>> Remove both.
>>
>> Look at what GPIO core does.
>
> I've checked the GPIO core, we need the
> sprd_pmic_eic_direction_input() returns 0, since user can set GPIOD_IN
> flag when requesting one GPIO, otherwise it will return errors.
Right. I thought it depends on presence of direction_output().
> We also need one dummy sprd_pmic_eic_set() when setting debounce for
> one GPIO, otherwise it will return errors.
This is pretty much a "feature" of GPIO framework. It shouldn't
require ->set() by logic if there is no output facility.
OK.
>>> + for (n = 0; n < chip->ngpio; n++) {
>>> + if (!(BIT(n) & val))
>>
>> for_each_set_bit().
>>
>> At some point you may need just to go across lib/ in the kernel and
>> see what we have there.
>
> I've considered the for_each_set_bit(), it need one 'unsigned long'
> type parameter, but we get the value from regmap is 'u32' type. So we
> need one extra conversion from 'u32' to 'unsigned long' like:
>
> unsigned long reg = val;
>
> for_each_set_bit(n, ®, chip->ngpio) {
> .......
> }
>
> If you like this conversion, then I can change to use
> for_each_set_bit(). Thanks.
Wouldn't it work like
unsigned long val;
...regmap_read(..., &val);
?
--
With Best Regards,
Andy Shevchenko
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