[PATCH RESEND v2 0/2] pinctrl-meson: two small improvements

[PATCH RESEND v2 0/2] pinctrl-meson: two small improvements

[Martin Blumenstingl]

While playing with audio output on Meson8b I found out that the
vendor kernel uses a custom version of the GPIO_PULL_UP flag. I
suspect that we will need this for audio support on Meson8b and/or
Meson8m2 but I don't see it hurt other platforms.

Also while comparing the register bits with the GPIO direction (of
GPIOs exported to sysfs) I sometimes had a mismatch. This also wires
up gpio_chip.get_direction to have sysfs and the actual registers in
sync.


Changes since v1 from [0]:
- re-send as non-"RFC" because I only got one comment in the past week
  for patch #2. Jerome pointed out an alternative way to GPIO_PULL_UP
  and GPIO_PULL_DOWN. However, this doesn't invalidate the patch, it
  just means that there are two ways to achieve the same goal.


[0] https://patchwork.kernel.org/cover/11484185/


Martin Blumenstingl (2):
  pinctrl: meson: implement the gpio_chip get_direction callback
  pinctrl: meson: wire up the gpio_chip's set_config callback

 drivers/pinctrl/meson/pinctrl-meson.c | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

-- 
2.26.1


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[PATCH RESEND v2 1/2] pinctrl: meson: implement the gpio_chip get_direction callback

[Martin Blumenstingl]

Implement the get_direction callback so we read the direction from the
actual GPIO controller register. This is recommended by the gpio_chip
kernel doc.

Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
---
 drivers/pinctrl/meson/pinctrl-meson.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/drivers/pinctrl/meson/pinctrl-meson.c b/drivers/pinctrl/meson/pinctrl-meson.c
index bbc919bef2bf..291f3078e7c7 100644
--- a/drivers/pinctrl/meson/pinctrl-meson.c
+++ b/drivers/pinctrl/meson/pinctrl-meson.c
@@ -549,6 +549,18 @@ static const struct pinconf_ops meson_pinconf_ops = {
 	.is_generic		= true,
 };
 
+static int meson_gpio_get_direction(struct gpio_chip *chip, unsigned gpio)
+{
+	struct meson_pinctrl *pc = gpiochip_get_data(chip);
+	int ret;
+
+	ret = meson_pinconf_get_output(pc, gpio);
+	if (ret < 0)
+		return ret;
+
+	return ret ? GPIO_LINE_DIRECTION_OUT : GPIO_LINE_DIRECTION_IN;
+}
+
 static int meson_gpio_direction_input(struct gpio_chip *chip, unsigned gpio)
 {
 	return meson_pinconf_set_output(gpiochip_get_data(chip), gpio, false);
@@ -591,6 +603,7 @@ static int meson_gpiolib_register(struct meson_pinctrl *pc)
 	pc->chip.parent = pc->dev;
 	pc->chip.request = gpiochip_generic_request;
 	pc->chip.free = gpiochip_generic_free;
+	pc->chip.get_direction = meson_gpio_get_direction;
 	pc->chip.direction_input = meson_gpio_direction_input;
 	pc->chip.direction_output = meson_gpio_direction_output;
 	pc->chip.get = meson_gpio_get;
-- 
2.26.1


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[PATCH RESEND v2 2/2] pinctrl: meson: wire up the gpio_chip's set_config callback

[Martin Blumenstingl]

Use gpiochip_generic_config for the gpio_chip's set_config callback so
GPIO flags like GPIO_PULL_UP or GPIO_PULL_DOWN can be used in the board
.dts descriptions.
This is required for some Meson8m2 boards where GPIO_BSD_EN provides the
"MUTE" signal and requires enabling the internal pull-up resistor.

Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
---
 drivers/pinctrl/meson/pinctrl-meson.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/pinctrl/meson/pinctrl-meson.c b/drivers/pinctrl/meson/pinctrl-meson.c
index 291f3078e7c7..079f8ee8d353 100644
--- a/drivers/pinctrl/meson/pinctrl-meson.c
+++ b/drivers/pinctrl/meson/pinctrl-meson.c
@@ -603,6 +603,7 @@ static int meson_gpiolib_register(struct meson_pinctrl *pc)
 	pc->chip.parent = pc->dev;
 	pc->chip.request = gpiochip_generic_request;
 	pc->chip.free = gpiochip_generic_free;
+	pc->chip.set_config = gpiochip_generic_config;
 	pc->chip.get_direction = meson_gpio_get_direction;
 	pc->chip.direction_input = meson_gpio_direction_input;
 	pc->chip.direction_output = meson_gpio_direction_output;
-- 
2.26.1


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Re: [PATCH RESEND v2 0/2] pinctrl-meson: two small improvements

[Linus Walleij]

On Fri, Apr 17, 2020 at 8:34 PM Martin Blumenstingl
<martin.blumenstingl@googlemail.com> wrote:

> While playing with audio output on Meson8b I found out that the
> vendor kernel uses a custom version of the GPIO_PULL_UP flag. I
> suspect that we will need this for audio support on Meson8b and/or
> Meson8m2 but I don't see it hurt other platforms.
>
> Also while comparing the register bits with the GPIO direction (of
> GPIOs exported to sysfs) I sometimes had a mismatch. This also wires
> up gpio_chip.get_direction to have sysfs and the actual registers in
> sync.

Patches applied.

Yours,
Linus Walleij

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