pps: move idr stuff to pps.c

[mv-sheeva.git] / drivers / pps / pps.c

diff --git a/drivers/pps/pps.c b/drivers/pps/pps.c
index 9f7c2e858dd03e717c4f24837a8a6e0aa2b2dbba..79b44557813225fec09d2e902c111f774722aafd 100644 (file)
--- a/drivers/pps/pps.c
+++ b/drivers/pps/pps.c
@@ -30,6 +30,7 @@
 #include <linux/cdev.h>
 #include <linux/poll.h>
 #include <linux/pps_kernel.h>
+#include <linux/slab.h>
 
 /*
  * Local variables
@@ -38,6 +39,9 @@
 static dev_t pps_devt;
 static struct class *pps_class;
 
+static DEFINE_SPINLOCK(pps_idr_lock);
+static DEFINE_IDR(pps_idr);
+
 /*
  * Char device methods
  */
@@ -229,11 +233,48 @@ static const struct file_operations pps_cdev_fops = {
        .release        = pps_cdev_release,
 };
 
+static void pps_device_destruct(struct device *dev)
+{
+       struct pps_device *pps = dev_get_drvdata(dev);
+
+       /* release id here to protect others from using it while it's
+        * still in use */
+       spin_lock_irq(&pps_idr_lock);
+       idr_remove(&pps_idr, pps->id);
+       spin_unlock_irq(&pps_idr_lock);
+
+       kfree(dev);
+       kfree(pps);
+}
+
 int pps_register_cdev(struct pps_device *pps)
 {
        int err;
        dev_t devt;
 
+       /* Get new ID for the new PPS source */
+       if (idr_pre_get(&pps_idr, GFP_KERNEL) == 0)
+               return -ENOMEM;
+
+       /* Now really allocate the PPS source.
+        * After idr_get_new() calling the new source will be freely available
+        * into the kernel.
+        */
+       spin_lock_irq(&pps_idr_lock);
+       err = idr_get_new(&pps_idr, pps, &pps->id);
+       spin_unlock_irq(&pps_idr_lock);
+
+       if (err < 0)
+               return err;
+
+       pps->id &= MAX_ID_MASK;
+       if (pps->id >= PPS_MAX_SOURCES) {
+               pr_err("%s: too many PPS sources in the system\n",
+                                       pps->info.name);
+               err = -EBUSY;
+               goto free_idr;
+       }
+
        devt = MKDEV(MAJOR(pps_devt), pps->id);
 
        cdev_init(&pps->cdev, &pps_cdev_fops);
@@ -243,13 +284,15 @@ int pps_register_cdev(struct pps_device *pps)
        if (err) {
                pr_err("%s: failed to add char device %d:%d\n",
                                pps->info.name, MAJOR(pps_devt), pps->id);
-               return err;
+               goto free_idr;
        }
        pps->dev = device_create(pps_class, pps->info.dev, devt, pps,
                                                        "pps%d", pps->id);
        if (IS_ERR(pps->dev))
                goto del_cdev;
 
+       pps->dev->release = pps_device_destruct;
+
        pr_debug("source %s got cdev (%d:%d)\n", pps->info.name,
                        MAJOR(pps_devt), pps->id);
 
@@ -258,6 +301,11 @@ int pps_register_cdev(struct pps_device *pps)
 del_cdev:
        cdev_del(&pps->cdev);
 
+free_idr:
+       spin_lock_irq(&pps_idr_lock);
+       idr_remove(&pps_idr, pps->id);
+       spin_unlock_irq(&pps_idr_lock);
+
        return err;
 }