Commit 65194cb1 authored by Geert Uytterhoeven's avatar Geert Uytterhoeven Committed by Linus Walleij
Browse files

gpio: rcar: Fine-grained Runtime PM support 



Currently gpio modules are runtime-resumed at probe time. This means the
gpio module will be active all the time (except during system suspend,
if not configured as a wake-up source).

While an R-Car Gen2 gpio module retains pins configured for output at
the requested level while put in standby mode, gpio registercannot be
accessed while suspended.  Unfortunately pm_runtime_get_sync() cannot be
called from all contexts where gpio register access is needed. Hence
move the Runtime PM handling from probe/remove time to gpio request/free
time, which is probably the best we can do.

On r8a7791/koelsch, gpio modules 0, 1, 3, and 4 are now suspended during
normal use (gpio2 is used for LEDs and regulators, gpio5 for keys, gpio6
for SD-Card CD & WP, gpio7 for keys and regulators).

Signed-off-by: default avatarGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: default avatarLinus Walleij <linus.walleij@linaro.org>
parent 527b397a

drivers/gpio/gpio-rcar.c

+16 −4
Original line number Original line Diff line number Diff line
@@ -251,17 +251,32 @@ static void gpio_rcar_config_general_input_output_mode(struct gpio_chip *chip, 




static int gpio_rcar_request(struct gpio_chip *chip, unsigned offset)

static int gpio_rcar_request(struct gpio_chip *chip, unsigned offset)

{

{

	return pinctrl_request_gpio(chip->base + offset);

	struct gpio_rcar_priv *p = gpio_to_priv(chip);

	int error;



	error = pm_runtime_get_sync(&p->pdev->dev);

	if (error < 0)

		return error;



	error = pinctrl_request_gpio(chip->base + offset);

	if (error)

		pm_runtime_put(&p->pdev->dev);



	return error;

}

}





static void gpio_rcar_free(struct gpio_chip *chip, unsigned offset)

static void gpio_rcar_free(struct gpio_chip *chip, unsigned offset)

{

{

	struct gpio_rcar_priv *p = gpio_to_priv(chip);



	pinctrl_free_gpio(chip->base + offset);

	pinctrl_free_gpio(chip->base + offset);





	/* Set the GPIO as an input to ensure that the next GPIO request won't

	/* Set the GPIO as an input to ensure that the next GPIO request won't

	 * drive the GPIO pin as an output.

	 * drive the GPIO pin as an output.

	 */

	 */

	gpio_rcar_config_general_input_output_mode(chip, offset, false);

	gpio_rcar_config_general_input_output_mode(chip, offset, false);



	pm_runtime_put(&p->pdev->dev);

}

}





static int gpio_rcar_direction_input(struct gpio_chip *chip, unsigned offset)

static int gpio_rcar_direction_input(struct gpio_chip *chip, unsigned offset)
@@ -405,7 +420,6 @@ static int gpio_rcar_probe(struct platform_device *pdev) 
	}

	}





	pm_runtime_enable(dev);

	pm_runtime_enable(dev);

	pm_runtime_get_sync(dev);





	io = platform_get_resource(pdev, IORESOURCE_MEM, 0);

	io = platform_get_resource(pdev, IORESOURCE_MEM, 0);

	irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);

	irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
@@ -487,7 +501,6 @@ static int gpio_rcar_probe(struct platform_device *pdev) 
err1:

err1:

	gpiochip_remove(gpio_chip);

	gpiochip_remove(gpio_chip);

err0:

err0:

	pm_runtime_put(dev);

	pm_runtime_disable(dev);

	pm_runtime_disable(dev);

	return ret;

	return ret;

}

}
@@ -498,7 +511,6 @@ static int gpio_rcar_remove(struct platform_device *pdev) 




	gpiochip_remove(&p->gpio_chip);

	gpiochip_remove(&p->gpio_chip);





	pm_runtime_put(&pdev->dev);

	pm_runtime_disable(&pdev->dev);

	pm_runtime_disable(&pdev->dev);

	return 0;

	return 0;

}

}

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