[media] rc-core: use an IDA rather than a bitmap

This patch changes rc-core to use the kernel facilities that are already
available for handling unique numbers instead of rolling its own bitmap
stuff.

Signed-off-by: David Härdeman <david@hardeman.nu>
Tested-by: Stefan Lippers-Hollmann <s.l-h@gmx.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

drivers/media/rc/rc-main.c

@@ -18,17 +18,15 @@
 #include <linux/input.h>
 #include <linux/leds.h>
 #include <linux/slab.h>
+#include <linux/idr.h>
 #include <linux/device.h>
 #include <linux/module.h>
 #include "rc-core-priv.h"
 
-/* Bitmap to store allocated device numbers from 0 to IRRCV_NUM_DEVICES - 1 */
-#define IRRCV_NUM_DEVICES      256
-static DECLARE_BITMAP(ir_core_dev_number, IRRCV_NUM_DEVICES);
-
 /* Sizes are in bytes, 256 bytes allows for 32 entries on x64 */
 #define IR_TAB_MIN_SIZE	256
 #define IR_TAB_MAX_SIZE	8192
+#define RC_DEV_MAX	256
 
 /* FIXME: IR_KEYPRESS_TIMEOUT should be protocol specific */
 #define IR_KEYPRESS_TIMEOUT 250
@@ -38,6 +36,9 @@ static LIST_HEAD(rc_map_list);
 static DEFINE_SPINLOCK(rc_map_lock);
 static struct led_trigger *led_feedback;
 
+/* Used to keep track of rc devices */
+static DEFINE_IDA(rc_ida);
+
 static struct rc_map_list *seek_rc_map(const char *name)
 {
 	struct rc_map_list *map = NULL;
@@ -1311,7 +1312,9 @@ int rc_register_device(struct rc_dev *dev)
 	static bool raw_init = false; /* raw decoders loaded? */
 	struct rc_map *rc_map;
 	const char *path;
-	int rc, devno, attr = 0;
+	int attr = 0;
+	int minor;
+	int rc;
 
 	if (!dev || !dev->map_name)
 		return -EINVAL;
@@ -1331,13 +1334,13 @@ int rc_register_device(struct rc_dev *dev)
 	if (dev->close)
 		dev->input_dev->close = ir_close;
 
-	do {
-		devno = find_first_zero_bit(ir_core_dev_number,
-					    IRRCV_NUM_DEVICES);
-		/* No free device slots */
-		if (devno >= IRRCV_NUM_DEVICES)
-			return -ENOMEM;
-	} while (test_and_set_bit(devno, ir_core_dev_number));
+	minor = ida_simple_get(&rc_ida, 0, RC_DEV_MAX, GFP_KERNEL);
+	if (minor < 0)
+		return minor;
+
+	dev->minor = minor;
+	dev_set_name(&dev->dev, "rc%u", dev->minor);
+	dev_set_drvdata(&dev->dev, dev);
 
 	dev->dev.groups = dev->sysfs_groups;
 	dev->sysfs_groups[attr++] = &rc_dev_protocol_attr_grp;
@@ -1357,9 +1360,6 @@ int rc_register_device(struct rc_dev *dev)
 	 */
 	mutex_lock(&dev->lock);
 
-	dev->devno = devno;
-	dev_set_name(&dev->dev, "rc%ld", dev->devno);
-	dev_set_drvdata(&dev->dev, dev);
 	rc = device_add(&dev->dev);
 	if (rc)
 		goto out_unlock;
@@ -1435,8 +1435,8 @@ int rc_register_device(struct rc_dev *dev)
 
 	mutex_unlock(&dev->lock);
 
-	IR_dprintk(1, "Registered rc%ld (driver: %s, remote: %s, mode %s)\n",
-		   dev->devno,
+	IR_dprintk(1, "Registered rc%u (driver: %s, remote: %s, mode %s)\n",
+		   dev->minor,
 		   dev->driver_name ? dev->driver_name : "unknown",
 		   rc_map->name ? rc_map->name : "unknown",
 		   dev->driver_type == RC_DRIVER_IR_RAW ? "raw" : "cooked");
@@ -1455,7 +1455,7 @@ out_dev:
 	device_del(&dev->dev);
 out_unlock:
 	mutex_unlock(&dev->lock);
-	clear_bit(dev->devno, ir_core_dev_number);
+	ida_simple_remove(&rc_ida, minor);
 	return rc;
 }
 EXPORT_SYMBOL_GPL(rc_register_device);
@@ -1467,8 +1467,6 @@ void rc_unregister_device(struct rc_dev *dev)
 
 	del_timer_sync(&dev->timer_keyup);
 
-	clear_bit(dev->devno, ir_core_dev_number);
-
 	if (dev->driver_type == RC_DRIVER_IR_RAW)
 		ir_raw_event_unregister(dev);
 
@@ -1481,6 +1479,8 @@ void rc_unregister_device(struct rc_dev *dev)
 
 	device_del(&dev->dev);
 
+	ida_simple_remove(&rc_ida, dev->minor);
+
 	rc_free_device(dev);
 }