pinctrl / gpio: Introduce .set_config() callback for GPIO chips

Currently we already have two pin configuration related callbacks
available for GPIO chips .set_single_ended() and .set_debounce(). In
future we expect to have even more, which does not scale well if we need
to add yet another callback to the GPIO chip structure for each possible
configuration parameter.

Better solution is to reuse what we already have available in the
generic pinconf.

To support this, we introduce a new .set_config() callback for GPIO
chips. The callback takes a single packed pin configuration value as
parameter. This can then be extended easily beyond what is currently
supported by just adding new types to the generic pinconf enum.

If the GPIO driver is backed up by a pinctrl driver the GPIO driver can
just assign gpiochip_generic_config() (introduced in this patch) to
.set_config and that will take care configuration requests are directed
to the pinctrl driver.

We then convert the existing drivers over .set_config() and finally
remove the .set_single_ended() and .set_debounce() callbacks.

Suggested-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

1 files changed, 9 insertions, 6 deletions

diff --git a/drivers/staging/greybus/gpio.c b/drivers/staging/greybus/gpio.c
index 250caa00de5e..51384bdde450 100644
--- a/drivers/staging/greybus/gpio.c
+++ b/drivers/staging/greybus/gpio.c
@@ -474,17 +474,20 @@ static void gb_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
 	gb_gpio_set_value_operation(ggc, (u8)offset, !!value);
 }
 
-static int gb_gpio_set_debounce(struct gpio_chip *chip, unsigned offset,
-					unsigned debounce)
+static int gb_gpio_set_config(struct gpio_chip *chip, unsigned offset,
+			      unsigned long config)
 {
 	struct gb_gpio_controller *ggc = gpio_chip_to_gb_gpio_controller(chip);
-	u16 usec;
+	u32 debounce;
 
+	if (pinconf_to_config_param(config) != PIN_CONFIG_INPUT_DEBOUNCE)
+		return -ENOTSUPP;
+
+	debounce = pinconf_to_config_argument(config);
 	if (debounce > U16_MAX)
 		return -EINVAL;
-	usec = (u16)debounce;
 
-	return gb_gpio_set_debounce_operation(ggc, (u8)offset, usec);
+	return gb_gpio_set_debounce_operation(ggc, (u8)offset, (u16)debounce);
 }
 
 static int gb_gpio_controller_setup(struct gb_gpio_controller *ggc)
@@ -689,7 +692,7 @@ static int gb_gpio_probe(struct gbphy_device *gbphy_dev,
 	gpio->direction_output = gb_gpio_direction_output;
 	gpio->get = gb_gpio_get;
 	gpio->set = gb_gpio_set;
-	gpio->set_debounce = gb_gpio_set_debounce;
+	gpio->set_config = gb_gpio_set_config;
 	gpio->to_irq = gb_gpio_to_irq;
 	gpio->base = -1;		/* Allocate base dynamically */
 	gpio->ngpio = ggc->line_max + 1;