Re: [PATCH] pinctrl: single: support GPIO for bits pinctrl

[Haojian Zhuang <haojian.zhuang@linaro.org>]

On 17 June 2015 at 15:17, Tony Lindgren <tony@atomide.com> wrote:
> * Jun Nie <jun.nie@linaro.org> [150616 18:58]:
>> Support GPIO for one register control multiple pins case
>> with calculating register offset first, then bit offset.
>>
>> Signed-off-by: Jun Nie <jun.nie@linaro.org>
>> ---
>>  drivers/pinctrl/pinctrl-single.c | 22 ++++++++++++++++++----
>>  1 file changed, 18 insertions(+), 4 deletions(-)
>>
>> diff --git a/drivers/pinctrl/pinctrl-single.c b/drivers/pinctrl/pinctrl-single.c
>> index 13b45f2..bd69d9a 100644
>> --- a/drivers/pinctrl/pinctrl-single.c
>> +++ b/drivers/pinctrl/pinctrl-single.c
>> @@ -494,7 +494,7 @@ static int pcs_request_gpio(struct pinctrl_dev *pctldev,
>>       struct pcs_device *pcs = pinctrl_dev_get_drvdata(pctldev);
>>       struct pcs_gpiofunc_range *frange = NULL;
>>       struct list_head *pos, *tmp;
>> -     int mux_bytes = 0;
>> +     int offset, mux_bytes = 0;
>>       unsigned data;
>>
>>       /* If function mask is null, return directly. */
>> @@ -507,9 +507,23 @@ static int pcs_request_gpio(struct pinctrl_dev *pctldev,
>>                       || pin < frange->offset)
>>                       continue;
>>               mux_bytes = pcs->width / BITS_PER_BYTE;
>> -             data = pcs->read(pcs->base + pin * mux_bytes) & ~pcs->fmask;
>> -             data |= frange->gpiofunc;
>> -             pcs->write(data, pcs->base + pin * mux_bytes);
>> +             if (pcs->bits_per_mux) {
>> +                     int pin_pos, byte_num, num_pins_in_register;
>> +
>> +                     num_pins_in_register = pcs->width / pcs->bits_per_pin;
>> +                     byte_num = (pcs->bits_per_pin * pin) / BITS_PER_BYTE;
>> +                     offset = (byte_num / mux_bytes) * mux_bytes;
>> +                     pin_pos = pin % num_pins_in_register;
>> +                     pin_pos *= pcs->bits_per_pin;
>> +                     data = pcs->read(pcs->base + offset) &
>> +                             ~(pcs->fmask << pin_pos);
>
> Should you check the pcs->fmask here too in case some bits are reserved?
>
>> +                     data |= frange->gpiofunc << pin_pos;
>> +             } else {
>> +                     offset = pin * mux_bytes;
>> +                     data = pcs->read(pcs->base + offset) & ~pcs->fmask;
>> +                     data |= frange->gpiofunc;
>> +             }
>> +             pcs->write(data, pcs->base + offset);
>>               break;
>>       }
>>       return 0;
>
> Other than that looks OK to me, would be good to also wait for Haojian's
> comments here.
>

I'm fine on this.

Reviewed-by: Haojian Zhuang <haojian.zhuang@linaro.org>
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