Orange Pi5 kernel

^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   1) // SPDX-License-Identifier: GPL-2.0-only
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   2) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   3)  * Media device node
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   4)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   5)  * Copyright (C) 2010 Nokia Corporation
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   6)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   7)  * Based on drivers/media/video/v4l2_dev.c code authored by
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   8)  *	Mauro Carvalho Chehab <mchehab@kernel.org> (version 2)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   9)  *	Alan Cox, <alan@lxorguk.ukuu.org.uk> (version 1)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  10)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  11)  * Contacts: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  12)  *	     Sakari Ailus <sakari.ailus@iki.fi>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  13)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  14)  * --
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  15)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  16)  * Generic media device node infrastructure to register and unregister
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  17)  * character devices using a dynamic major number and proper reference
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  18)  * counting.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  19)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  20) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  21) #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  22) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  23) #include <linux/errno.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  24) #include <linux/init.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  25) #include <linux/module.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  26) #include <linux/kernel.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  27) #include <linux/kmod.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  28) #include <linux/slab.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  29) #include <linux/mm.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  30) #include <linux/string.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  31) #include <linux/types.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  32) #include <linux/uaccess.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  33) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  34) #include <media/media-devnode.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  35) #include <media/media-device.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  36) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  37) #define MEDIA_NUM_DEVICES	256
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  38) #define MEDIA_NAME		"media"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  39) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  40) static dev_t media_dev_t;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  41) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  42) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  43)  *	Active devices
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  44)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  45) static DEFINE_MUTEX(media_devnode_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  46) static DECLARE_BITMAP(media_devnode_nums, MEDIA_NUM_DEVICES);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  47) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  48) /* Called when the last user of the media device exits. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  49) static void media_devnode_release(struct device *cd)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  50) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  51) 	struct media_devnode *devnode = to_media_devnode(cd);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  52) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  53) 	mutex_lock(&media_devnode_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  54) 	/* Mark device node number as free */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  55) 	clear_bit(devnode->minor, media_devnode_nums);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  56) 	mutex_unlock(&media_devnode_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  57) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  58) 	/* Release media_devnode and perform other cleanups as needed. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  59) 	if (devnode->release)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  60) 		devnode->release(devnode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  61) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  62) 	kfree(devnode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  63) 	pr_debug("%s: Media Devnode Deallocated\n", __func__);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  64) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  65) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  66) static struct bus_type media_bus_type = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  67) 	.name = MEDIA_NAME,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  68) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  69) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  70) static ssize_t media_read(struct file *filp, char __user *buf,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  71) 		size_t sz, loff_t *off)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  72) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  73) 	struct media_devnode *devnode = media_devnode_data(filp);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  74) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  75) 	if (!devnode->fops->read)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  76) 		return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  77) 	if (!media_devnode_is_registered(devnode))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  78) 		return -EIO;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  79) 	return devnode->fops->read(filp, buf, sz, off);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  80) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  81) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  82) static ssize_t media_write(struct file *filp, const char __user *buf,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  83) 		size_t sz, loff_t *off)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  84) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  85) 	struct media_devnode *devnode = media_devnode_data(filp);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  86) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  87) 	if (!devnode->fops->write)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  88) 		return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  89) 	if (!media_devnode_is_registered(devnode))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  90) 		return -EIO;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  91) 	return devnode->fops->write(filp, buf, sz, off);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  92) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  93) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  94) static __poll_t media_poll(struct file *filp,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  95) 			       struct poll_table_struct *poll)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  96) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  97) 	struct media_devnode *devnode = media_devnode_data(filp);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  98) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  99) 	if (!media_devnode_is_registered(devnode))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) 		return EPOLLERR | EPOLLHUP;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) 	if (!devnode->fops->poll)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) 		return DEFAULT_POLLMASK;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) 	return devnode->fops->poll(filp, poll);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) static long
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) __media_ioctl(struct file *filp, unsigned int cmd, unsigned long arg,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) 	      long (*ioctl_func)(struct file *filp, unsigned int cmd,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) 				 unsigned long arg))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) 	struct media_devnode *devnode = media_devnode_data(filp);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) 	if (!ioctl_func)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) 		return -ENOTTY;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) 	if (!media_devnode_is_registered(devnode))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) 		return -EIO;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) 	return ioctl_func(filp, cmd, arg);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) static long media_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) 	struct media_devnode *devnode = media_devnode_data(filp);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) 	return __media_ioctl(filp, cmd, arg, devnode->fops->ioctl);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) #ifdef CONFIG_COMPAT
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) static long media_compat_ioctl(struct file *filp, unsigned int cmd,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) 			       unsigned long arg)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) 	struct media_devnode *devnode = media_devnode_data(filp);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) 	return __media_ioctl(filp, cmd, arg, devnode->fops->compat_ioctl);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) #endif /* CONFIG_COMPAT */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) /* Override for the open function */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) static int media_open(struct inode *inode, struct file *filp)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) 	struct media_devnode *devnode;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) 	int ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) 	/* Check if the media device is available. This needs to be done with
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) 	 * the media_devnode_lock held to prevent an open/unregister race:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) 	 * without the lock, the device could be unregistered and freed between
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) 	 * the media_devnode_is_registered() and get_device() calls, leading to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) 	 * a crash.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) 	 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) 	mutex_lock(&media_devnode_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) 	devnode = container_of(inode->i_cdev, struct media_devnode, cdev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) 	/* return ENXIO if the media device has been removed
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) 	   already or if it is not registered anymore. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) 	if (!media_devnode_is_registered(devnode)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) 		mutex_unlock(&media_devnode_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159) 		return -ENXIO;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) 	/* and increase the device refcount */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) 	get_device(&devnode->dev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) 	mutex_unlock(&media_devnode_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) 	filp->private_data = devnode;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) 	if (devnode->fops->open) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) 		ret = devnode->fops->open(filp);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169) 		if (ret) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170) 			put_device(&devnode->dev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) 			filp->private_data = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172) 			return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179) /* Override for the release function */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) static int media_release(struct inode *inode, struct file *filp)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182) 	struct media_devnode *devnode = media_devnode_data(filp);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184) 	if (devnode->fops->release)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185) 		devnode->fops->release(filp);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187) 	filp->private_data = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189) 	/* decrease the refcount unconditionally since the release()
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190) 	   return value is ignored. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191) 	put_device(&devnode->dev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193) 	pr_debug("%s: Media Release\n", __func__);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 197) static const struct file_operations media_devnode_fops = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 198) 	.owner = THIS_MODULE,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 199) 	.read = media_read,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 200) 	.write = media_write,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 201) 	.open = media_open,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 202) 	.unlocked_ioctl = media_ioctl,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 203) #ifdef CONFIG_COMPAT
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 204) 	.compat_ioctl = media_compat_ioctl,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 205) #endif /* CONFIG_COMPAT */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 206) 	.release = media_release,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 207) 	.poll = media_poll,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 208) 	.llseek = no_llseek,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 209) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 210) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 211) int __must_check media_devnode_register(struct media_device *mdev,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 212) 					struct media_devnode *devnode,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 213) 					struct module *owner)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 214) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 215) 	int minor;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 216) 	int ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 217) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 218) 	/* Part 1: Find a free minor number */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 219) 	mutex_lock(&media_devnode_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 220) 	minor = find_next_zero_bit(media_devnode_nums, MEDIA_NUM_DEVICES, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 221) 	if (minor == MEDIA_NUM_DEVICES) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 222) 		mutex_unlock(&media_devnode_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 223) 		pr_err("could not get a free minor\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 224) 		kfree(devnode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 225) 		return -ENFILE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 226) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 227) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 228) 	set_bit(minor, media_devnode_nums);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 229) 	mutex_unlock(&media_devnode_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 230) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 231) 	devnode->minor = minor;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 232) 	devnode->media_dev = mdev;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 233) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 234) 	/* Part 1: Initialize dev now to use dev.kobj for cdev.kobj.parent */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 235) 	devnode->dev.bus = &media_bus_type;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 236) 	devnode->dev.devt = MKDEV(MAJOR(media_dev_t), devnode->minor);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 237) 	devnode->dev.release = media_devnode_release;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 238) 	if (devnode->parent)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 239) 		devnode->dev.parent = devnode->parent;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 240) 	dev_set_name(&devnode->dev, "media%d", devnode->minor);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 241) 	device_initialize(&devnode->dev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 242) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 243) 	/* Part 2: Initialize the character device */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 244) 	cdev_init(&devnode->cdev, &media_devnode_fops);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 245) 	devnode->cdev.owner = owner;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 246) 	kobject_set_name(&devnode->cdev.kobj, "media%d", devnode->minor);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 247) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 248) 	/* Part 3: Add the media and char device */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 249) 	ret = cdev_device_add(&devnode->cdev, &devnode->dev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 250) 	if (ret < 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 251) 		pr_err("%s: cdev_device_add failed\n", __func__);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 252) 		goto cdev_add_error;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 253) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 254) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 255) 	/* Part 4: Activate this minor. The char device can now be used. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 256) 	set_bit(MEDIA_FLAG_REGISTERED, &devnode->flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 257) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 258) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 259) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 260) cdev_add_error:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 261) 	mutex_lock(&media_devnode_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 262) 	clear_bit(devnode->minor, media_devnode_nums);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 263) 	devnode->media_dev = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 264) 	mutex_unlock(&media_devnode_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 265) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 266) 	put_device(&devnode->dev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 267) 	return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 268) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 269) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 270) void media_devnode_unregister_prepare(struct media_devnode *devnode)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 271) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 272) 	/* Check if devnode was ever registered at all */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 273) 	if (!media_devnode_is_registered(devnode))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 274) 		return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 275) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 276) 	mutex_lock(&media_devnode_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 277) 	clear_bit(MEDIA_FLAG_REGISTERED, &devnode->flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 278) 	mutex_unlock(&media_devnode_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 279) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 280) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 281) void media_devnode_unregister(struct media_devnode *devnode)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 282) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 283) 	mutex_lock(&media_devnode_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 284) 	/* Delete the cdev on this minor as well */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 285) 	cdev_device_del(&devnode->cdev, &devnode->dev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 286) 	devnode->media_dev = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 287) 	mutex_unlock(&media_devnode_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 288) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 289) 	put_device(&devnode->dev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 290) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 291) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 292) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 293)  *	Initialise media for linux
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 294)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 295) static int __init media_devnode_init(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 296) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 297) 	int ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 298) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 299) 	pr_info("Linux media interface: v0.10\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 300) 	ret = alloc_chrdev_region(&media_dev_t, 0, MEDIA_NUM_DEVICES,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 301) 				  MEDIA_NAME);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 302) 	if (ret < 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 303) 		pr_warn("unable to allocate major\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 304) 		return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 305) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 306) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 307) 	ret = bus_register(&media_bus_type);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 308) 	if (ret < 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 309) 		unregister_chrdev_region(media_dev_t, MEDIA_NUM_DEVICES);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 310) 		pr_warn("bus_register failed\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 311) 		return -EIO;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 312) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 313) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 314) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 315) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 316) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 317) static void __exit media_devnode_exit(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 318) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 319) 	bus_unregister(&media_bus_type);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 320) 	unregister_chrdev_region(media_dev_t, MEDIA_NUM_DEVICES);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 321) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 322) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 323) subsys_initcall(media_devnode_init);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 324) module_exit(media_devnode_exit)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 325) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 326) MODULE_AUTHOR("Laurent Pinchart <laurent.pinchart@ideasonboard.com>");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 327) MODULE_DESCRIPTION("Device node registration for media drivers");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 328) MODULE_LICENSE("GPL");