Hi,
On Mon, Jun 18, 2018 at 1:52 PM, Stephen Boyd <swb...@chromium.org> wrote:
> We rely on devices to use pinmuxing configurations in DT to select the
> GPIO function (function 0) if they're going to use the gpio in GPIO
> mode. Let's simplify things for driver authors by implementing
> gpio_request_enable() for this pinctrl driver to mux out the GPIO
> function when the gpio is use from gpiolib.
>
> Cc: Bjorn Andersson <bjorn.anders...@linaro.org>
> Cc: Doug Anderson <diand...@chromium.org>
> Signed-off-by: Stephen Boyd <swb...@chromium.org>
> ---
> drivers/pinctrl/qcom/pinctrl-msm.c | 16 ++++++++++++++++
> 1 file changed, 16 insertions(+)
>
> diff --git a/drivers/pinctrl/qcom/pinctrl-msm.c
> b/drivers/pinctrl/qcom/pinctrl-msm.c
> index 3563c4394837..eacfc5b85f7f 100644
> --- a/drivers/pinctrl/qcom/pinctrl-msm.c
> +++ b/drivers/pinctrl/qcom/pinctrl-msm.c
> @@ -176,11 +176,27 @@ static int msm_pinmux_set_mux(struct pinctrl_dev
> *pctldev,
> return 0;
> }
>
> +static int msm_pinmux_request_gpio(struct pinctrl_dev *pctldev,
> + struct pinctrl_gpio_range *range,
> + unsigned offset)
> +{
> + struct msm_pinctrl *pctrl = pinctrl_dev_get_drvdata(pctldev);
> + const struct msm_pingroup *g = &pctrl->soc->groups[offset];
> +
> + /* No funcs? Probably ACPI so can't do anything here */
> + if (!g->nfuncs)
> + return 0;
Is there a reason why you'd want to return 0 instead of some sort of
error code? Wouldn't you want to know that this pin can't be a GPIO?
Another non-ACPI example is sdc2 on sdm845 and it seems like you'd
want to know if someone tried to set one of those as a GPIO.
...oh, but I guess ufs_reset also has no funcs but it still probably
wants to use the GPIO framework to write something. Hrmmm... Maybe
check if either in_bit or out_bit is not -1?
> +
> + /* For now assume function 0 is GPIO because it always is */
> + return msm_pinmux_set_mux(pctldev, 0, offset);
nit: should you be consistent with msm_pinmux_set_mux() and call it
"group" instead of "offset"? It looks like it's supposed to be the
same thing...
-Doug
