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[media] media: lirc_dev: use an IDA instead of an array to keep track of registered devices
Using the kernel-provided IDA simplifies the code and makes it possible to remove the lirc_dev_lock mutex. Signed-off-by: David Härdeman <david@hardeman.nu> Signed-off-by: Sean Young <sean@mess.org> Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
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parent
3381b779a7
commit
46c8f47711
2 changed files with 12 additions and 25 deletions
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@ -24,6 +24,7 @@
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#include <linux/mutex.h>
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#include <linux/device.h>
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#include <linux/cdev.h>
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#include <linux/idr.h>
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#include <media/rc-core.h>
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#include <media/lirc.h>
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@ -46,10 +47,9 @@ struct irctl {
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struct cdev cdev;
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};
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/* This mutex protects the irctls array */
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static DEFINE_MUTEX(lirc_dev_lock);
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static struct irctl *irctls[MAX_IRCTL_DEVICES];
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/* Used to keep track of allocated lirc devices */
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#define LIRC_MAX_DEVICES 256
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static DEFINE_IDA(lirc_ida);
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/* Only used for sysfs but defined to void otherwise */
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static struct class *lirc_class;
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@ -69,9 +69,6 @@ static void lirc_release(struct device *ld)
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{
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struct irctl *ir = container_of(ld, struct irctl, dev);
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mutex_lock(&lirc_dev_lock);
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irctls[ir->d.minor] = NULL;
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mutex_unlock(&lirc_dev_lock);
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lirc_free_buffer(ir);
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kfree(ir);
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}
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@ -109,7 +106,7 @@ static int lirc_allocate_buffer(struct irctl *ir)
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int lirc_register_driver(struct lirc_driver *d)
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{
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struct irctl *ir;
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unsigned int minor;
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int minor;
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int err;
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if (!d) {
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@ -171,28 +168,17 @@ int lirc_register_driver(struct lirc_driver *d)
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d->rbuf = ir->buf;
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}
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mutex_lock(&lirc_dev_lock);
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/* find first free slot for driver */
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for (minor = 0; minor < MAX_IRCTL_DEVICES; minor++)
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if (!irctls[minor])
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break;
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if (minor == MAX_IRCTL_DEVICES) {
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dev_err(d->dev, "no free slots for drivers!\n");
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mutex_unlock(&lirc_dev_lock);
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minor = ida_simple_get(&lirc_ida, 0, LIRC_MAX_DEVICES, GFP_KERNEL);
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if (minor < 0) {
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lirc_free_buffer(ir);
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kfree(ir);
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return -ENOMEM;
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return minor;
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}
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irctls[minor] = ir;
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d->irctl = ir;
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d->minor = minor;
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ir->d.minor = minor;
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mutex_unlock(&lirc_dev_lock);
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device_initialize(&ir->dev);
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ir->dev.devt = MKDEV(MAJOR(lirc_base_dev), ir->d.minor);
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ir->dev.class = lirc_class;
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@ -206,6 +192,7 @@ int lirc_register_driver(struct lirc_driver *d)
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err = cdev_device_add(&ir->cdev, &ir->dev);
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if (err) {
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ida_simple_remove(&lirc_ida, minor);
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put_device(&ir->dev);
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return err;
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}
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@ -244,6 +231,7 @@ void lirc_unregister_driver(struct lirc_driver *d)
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mutex_unlock(&ir->mutex);
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ida_simple_remove(&lirc_ida, d->minor);
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put_device(&ir->dev);
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}
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EXPORT_SYMBOL(lirc_unregister_driver);
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@ -540,7 +528,7 @@ static int __init lirc_dev_init(void)
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return PTR_ERR(lirc_class);
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}
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retval = alloc_chrdev_region(&lirc_base_dev, 0, MAX_IRCTL_DEVICES,
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retval = alloc_chrdev_region(&lirc_base_dev, 0, LIRC_MAX_DEVICES,
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"BaseRemoteCtl");
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if (retval) {
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class_destroy(lirc_class);
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@ -557,7 +545,7 @@ static int __init lirc_dev_init(void)
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static void __exit lirc_dev_exit(void)
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{
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class_destroy(lirc_class);
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unregister_chrdev_region(lirc_base_dev, MAX_IRCTL_DEVICES);
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unregister_chrdev_region(lirc_base_dev, LIRC_MAX_DEVICES);
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pr_info("module unloaded\n");
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}
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@ -9,7 +9,6 @@
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#ifndef _LINUX_LIRC_DEV_H
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#define _LINUX_LIRC_DEV_H
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#define MAX_IRCTL_DEVICES 8
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#define BUFLEN 16
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#include <linux/slab.h>
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