From 65194cb174b873448b208eb6e04ecb72237af76e Mon Sep 17 00:00:00 2001 From: Geert Uytterhoeven Date: Thu, 25 Jun 2015 16:45:57 +0200 Subject: [PATCH] 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: Geert Uytterhoeven Signed-off-by: Linus Walleij --- drivers/gpio/gpio-rcar.c | 20 ++++++++++++++++---- 1 file changed, 16 insertions(+), 4 deletions(-) diff --git a/drivers/gpio/gpio-rcar.c b/drivers/gpio/gpio-rcar.c index 1e14a6c74ed1..4fc13ce9c60a 100644 --- a/drivers/gpio/gpio-rcar.c +++ b/drivers/gpio/gpio-rcar.c @@ -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) { - 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) { + struct gpio_rcar_priv *p = gpio_to_priv(chip); + pinctrl_free_gpio(chip->base + offset); /* Set the GPIO as an input to ensure that the next GPIO request won't * drive the GPIO pin as an output. */ 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) @@ -405,7 +420,6 @@ static int gpio_rcar_probe(struct platform_device *pdev) } pm_runtime_enable(dev); - pm_runtime_get_sync(dev); io = platform_get_resource(pdev, IORESOURCE_MEM, 0); irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0); @@ -487,7 +501,6 @@ static int gpio_rcar_probe(struct platform_device *pdev) err1: gpiochip_remove(gpio_chip); err0: - pm_runtime_put(dev); pm_runtime_disable(dev); return ret; } @@ -498,7 +511,6 @@ static int gpio_rcar_remove(struct platform_device *pdev) gpiochip_remove(&p->gpio_chip); - pm_runtime_put(&pdev->dev); pm_runtime_disable(&pdev->dev); return 0; }