* Jun Nie <[email protected]> [150706 06:59]:
> Support GPIO for one register control multiple pins case
> with calculating register offset first, then bit offset.
>
> Signed-off-by: Jun Nie <[email protected]>
> ---
> 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..4f23ef0 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);
> + data |= (frange->gpiofunc & pcs->fmask) << pin_pos;
I don't quite follow you here.. The pcs->fmask is for the whole register,
so I think the fmask should be checked the same way in this case also:
data = pcs->read(pcs->base + offset) & ~pcs->fmask;
...
I don't think we can safely assume the fmask would behave differently
in this case.
Regards,
Tony
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