On Fri 22 Jun 10:58 PDT 2018, Bjorn Andersson wrote:
> On Mon 18 Jun 13:52 PDT 2018, Stephen Boyd 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>
>
> Reviewed-by: Bjorn Andersson <bjorn.anders...@linaro.org>
>
On second thought, while reading patch 3, when would this be used?
While both patch 2 and 3 are convenient ways to get around the annoyance
of having to specify a pinmux state both patches then ends up relying on
some default pinconf state; which I think is bad.
Further more in situations like i2c-qup (downstream), where the pins are
requested as gpios in order to "bitbang" a reset this would mean that
the driver has to counter the convenience; by either switching in the
default pinmux at the end of probe or postponing the gpio_request() to
the invocation of reset and then, after issuing the gpio_release,
switching in the default pinmux explicitly again.
So I'm not sure we want this.
Regards,
Bjorn
> Regards,
> Bjorn
>
> > 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;
> > +
> > + /* For now assume function 0 is GPIO because it always is */
> > + return msm_pinmux_set_mux(pctldev, 0, offset);
> > +}
> > +
> > static const struct pinmux_ops msm_pinmux_ops = {
> > .request = msm_pinmux_request,
> > .get_functions_count = msm_get_functions_count,
> > .get_function_name = msm_get_function_name,
> > .get_function_groups = msm_get_function_groups,
> > + .gpio_request_enable = msm_pinmux_request_gpio,
> > .set_mux = msm_pinmux_set_mux,
> > };
> >
> > --
> > Sent by a computer through tubes
> >
