UIO: minor Kconfig fixes

[safe/jmp/linux-2.6] / drivers / uio / uio_pdrv_genirq.c

diff --git a/drivers/uio/uio_pdrv_genirq.c b/drivers/uio/uio_pdrv_genirq.c
index 3f06818..1ef3b8f 100644 (file)
--- 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");
@@ -148,6 +178,7 @@ static int uio_pdrv_genirq_probe(struct platform_device *pdev)
        return 0;
  bad1:
        kfree(priv);
+       pm_runtime_disable(&pdev->dev);
  bad0:
        return ret;
 }
@@ -157,16 +188,40 @@ 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 const 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,
        },
 };