Add support of clock adaptation for AXI GPIO driver. Signed-off-by: Srinivas Neeli <srinivas.neeli@xxxxxxxxxx> --- drivers/gpio/gpio-xilinx.c | 105 ++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 103 insertions(+), 2 deletions(-) diff --git a/drivers/gpio/gpio-xilinx.c b/drivers/gpio/gpio-xilinx.c index a9748b5198e6..26753ae58295 100644 --- a/drivers/gpio/gpio-xilinx.c +++ b/drivers/gpio/gpio-xilinx.c @@ -14,6 +14,8 @@ #include <linux/io.h> #include <linux/gpio/driver.h> #include <linux/slab.h> +#include <linux/pm_runtime.h> +#include <linux/clk.h> /* Register Offset Definitions */ #define XGPIO_DATA_OFFSET (0x0) /* Data register */ @@ -38,6 +40,7 @@ * @gpio_state: GPIO state shadow register * @gpio_dir: GPIO direction shadow register * @gpio_lock: Lock used for synchronization + * @clk: clock resource for this driver */ struct xgpio_instance { struct gpio_chip gc; @@ -45,7 +48,8 @@ struct xgpio_instance { unsigned int gpio_width[2]; u32 gpio_state[2]; u32 gpio_dir[2]; - spinlock_t gpio_lock[2]; + spinlock_t gpio_lock[2]; /* For serializing operations */ + struct clk *clk; }; static inline int xgpio_index(struct xgpio_instance *chip, int gpio) @@ -255,6 +259,70 @@ static void xgpio_save_regs(struct xgpio_instance *chip) chip->gpio_dir[1]); } +static int xgpio_request(struct gpio_chip *chip, unsigned int offset) +{ + int ret = pm_runtime_get_sync(chip->parent); + + /* + * If the device is already active pm_runtime_get() will return 1 on + * success, but gpio_request still needs to return 0. + */ + return ret < 0 ? ret : 0; +} + +static void xgpio_free(struct gpio_chip *chip, unsigned int offset) +{ + pm_runtime_put(chip->parent); +} + +static int __maybe_unused xgpio_suspend(struct device *dev) +{ + struct platform_device *pdev = to_platform_device(dev); + int irq = platform_get_irq(pdev, 0); + struct irq_data *data = irq_get_irq_data(irq); + + if (!irqd_is_wakeup_set(data)) + return pm_runtime_force_suspend(dev); + + return 0; +} + +static int __maybe_unused xgpio_resume(struct device *dev) +{ + struct platform_device *pdev = to_platform_device(dev); + int irq = platform_get_irq(pdev, 0); + struct irq_data *data = irq_get_irq_data(irq); + + if (!irqd_is_wakeup_set(data)) + return pm_runtime_force_resume(dev); + + return 0; +} + +static int __maybe_unused xgpio_runtime_suspend(struct device *dev) +{ + struct platform_device *pdev = to_platform_device(dev); + struct xgpio_instance *gpio = platform_get_drvdata(pdev); + + clk_disable(gpio->clk); + + return 0; +} + +static int __maybe_unused xgpio_runtime_resume(struct device *dev) +{ + struct platform_device *pdev = to_platform_device(dev); + struct xgpio_instance *gpio = platform_get_drvdata(pdev); + + return clk_enable(gpio->clk); +} + +static const struct dev_pm_ops xgpio_dev_pm_ops = { + SET_SYSTEM_SLEEP_PM_OPS(xgpio_suspend, xgpio_resume) + SET_RUNTIME_PM_OPS(xgpio_runtime_suspend, + xgpio_runtime_resume, NULL) +}; + /** * xgpio_of_probe - Probe method for the GPIO device. * @pdev: pointer to the platform device @@ -323,6 +391,8 @@ static int xgpio_probe(struct platform_device *pdev) chip->gc.direction_output = xgpio_dir_out; chip->gc.get = xgpio_get; chip->gc.set = xgpio_set; + chip->gc.request = xgpio_request; + chip->gc.free = xgpio_free; chip->gc.set_multiple = xgpio_set_multiple; chip->gc.label = dev_name(&pdev->dev); @@ -333,15 +403,45 @@ static int xgpio_probe(struct platform_device *pdev) return PTR_ERR(chip->regs); } + chip->clk = devm_clk_get(&pdev->dev, "s_axi_aclk"); + if (IS_ERR(chip->clk)) { + if (PTR_ERR(chip->clk) != -ENOENT) { + if (PTR_ERR(chip->clk) != -EPROBE_DEFER) + dev_err(&pdev->dev, "Input clock not found\n"); + return PTR_ERR(chip->clk); + } + /* + * Clock framework support is optional, continue on + * anyways if we don't find a matching clock. + */ + chip->clk = NULL; + } + status = clk_prepare_enable(chip->clk); + if (status < 0) { + dev_err(&pdev->dev, "Failed to prepare clk\n"); + return status; + } + pm_runtime_enable(&pdev->dev); + status = pm_runtime_get_sync(&pdev->dev); + if (status < 0) + goto err_unprepare_clk; + xgpio_save_regs(chip); status = devm_gpiochip_add_data(&pdev->dev, &chip->gc, chip); if (status) { dev_err(&pdev->dev, "failed to add GPIO chip\n"); - return status; + goto err_pm_put; } + pm_runtime_put(&pdev->dev); return 0; +err_pm_put: + pm_runtime_put(&pdev->dev); +err_unprepare_clk: + pm_runtime_disable(&pdev->dev); + clk_unprepare(chip->clk); + return status; } static const struct of_device_id xgpio_of_match[] = { @@ -356,6 +456,7 @@ static struct platform_driver xgpio_plat_driver = { .driver = { .name = "gpio-xilinx", .of_match_table = xgpio_of_match, + .pm = &xgpio_dev_pm_ops, }, }; -- 2.7.4