diff options
| -rw-r--r-- | drivers/uio/uio_pdrv_genirq.c | 54 |
1 files changed, 54 insertions, 0 deletions
diff --git a/drivers/uio/uio_pdrv_genirq.c b/drivers/uio/uio_pdrv_genirq.c index 3f06818..02347c5 100644 --- a/drivers/uio/uio_pdrv_genirq.c +++ b/drivers/uio/uio_pdrv_genirq.c @@ -20,6 +20,7 @@ #include <linux/bitops.h> #include <linux/interrupt.h> #include <linux/stringify.h> +#include <linux/pm_runtime.h> #define DRIVER_NAME "uio_pdrv_genirq" @@ -27,8 +28,27 @@ struct uio_pdrv_genirq_platdata { struct uio_info *uioinfo; spinlock_t lock; unsigned long flags; + struct platform_device *pdev; }; +static int uio_pdrv_genirq_open(struct uio_info *info, struct inode *inode) +{ + struct uio_pdrv_genirq_platdata *priv = info->priv; + + /* Wait until the Runtime PM code has woken up the device */ + pm_runtime_get_sync(&priv->pdev->dev); + return 0; +} + +static int uio_pdrv_genirq_release(struct uio_info *info, struct inode *inode) +{ + struct uio_pdrv_genirq_platdata *priv = info->priv; + + /* Tell the Runtime PM code that the device has become idle */ + pm_runtime_put_sync(&priv->pdev->dev); + return 0; +} + static irqreturn_t uio_pdrv_genirq_handler(int irq, struct uio_info *dev_info) { struct uio_pdrv_genirq_platdata *priv = dev_info->priv; @@ -97,6 +117,7 @@ static int uio_pdrv_genirq_probe(struct platform_device *pdev) priv->uioinfo = uioinfo; spin_lock_init(&priv->lock); priv->flags = 0; /* interrupt is enabled to begin with */ + priv->pdev = pdev; uiomem = &uioinfo->mem[0]; @@ -136,8 +157,17 @@ static int uio_pdrv_genirq_probe(struct platform_device *pdev) uioinfo->irq_flags |= IRQF_DISABLED; uioinfo->handler = uio_pdrv_genirq_handler; uioinfo->irqcontrol = uio_pdrv_genirq_irqcontrol; + uioinfo->open = uio_pdrv_genirq_open; + uioinfo->release = uio_pdrv_genirq_release; uioinfo->priv = priv; + /* Enable Runtime PM for this device: + * The device starts in suspended state to allow the hardware to be + * turned off by default. The Runtime PM bus code should power on the + * hardware and enable clocks at open(). + */ + pm_runtime_enable(&pdev->dev); + ret = uio_register_device(&pdev->dev, priv->uioinfo); if (ret) { dev_err(&pdev->dev, "unable to register uio device\n"); @@ -157,16 +187,40 @@ static int uio_pdrv_genirq_remove(struct platform_device *pdev) struct uio_pdrv_genirq_platdata *priv = platform_get_drvdata(pdev); uio_unregister_device(priv->uioinfo); + pm_runtime_disable(&pdev->dev); kfree(priv); return 0; } +static int uio_pdrv_genirq_runtime_nop(struct device *dev) +{ + /* Runtime PM callback shared between ->runtime_suspend() + * and ->runtime_resume(). Simply returns success. + * + * In this driver pm_runtime_get_sync() and pm_runtime_put_sync() + * are used at open() and release() time. This allows the + * Runtime PM code to turn off power to the device while the + * device is unused, ie before open() and after release(). + * + * This Runtime PM callback does not need to save or restore + * any registers since user space is responsbile for hardware + * register reinitialization after open(). + */ + return 0; +} + +static struct dev_pm_ops uio_pdrv_genirq_dev_pm_ops = { + .runtime_suspend = uio_pdrv_genirq_runtime_nop, + .runtime_resume = uio_pdrv_genirq_runtime_nop, +}; + static struct platform_driver uio_pdrv_genirq = { .probe = uio_pdrv_genirq_probe, .remove = uio_pdrv_genirq_remove, .driver = { .name = DRIVER_NAME, .owner = THIS_MODULE, + .pm = &uio_pdrv_genirq_dev_pm_ops, }, }; |
