On Fri 22 Jun 10:58 PDT 2018, Bjorn Andersson wrote:

On Mon 18 Jun 13:52 PDT 2018, Stephen Boyd wrote:

quoted

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 <redacted>

Reviewed-by: Bjorn Andersson <redacted>

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

quoted

Cc: Doug Anderson <dianders@chromium.org>
Signed-off-by: Stephen Boyd <redacted>
---
 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,
 };
 

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