Thomas Gleixner | 1802d0b | 2019-05-27 08:55:21 +0200 | [diff] [blame] | 1 | /* SPDX-License-Identifier: GPL-2.0-only */ |
Laurent Pinchart | cf4b921 | 2009-12-09 08:39:56 -0300 | [diff] [blame] | 2 | /* |
| 3 | * Media device node |
| 4 | * |
| 5 | * Copyright (C) 2010 Nokia Corporation |
| 6 | * |
| 7 | * Contacts: Laurent Pinchart <laurent.pinchart@ideasonboard.com> |
| 8 | * Sakari Ailus <sakari.ailus@iki.fi> |
| 9 | * |
Laurent Pinchart | cf4b921 | 2009-12-09 08:39:56 -0300 | [diff] [blame] | 10 | * -- |
| 11 | * |
| 12 | * Common functions for media-related drivers to register and unregister media |
| 13 | * device nodes. |
| 14 | */ |
| 15 | |
| 16 | #ifndef _MEDIA_DEVNODE_H |
| 17 | #define _MEDIA_DEVNODE_H |
| 18 | |
| 19 | #include <linux/poll.h> |
| 20 | #include <linux/fs.h> |
| 21 | #include <linux/device.h> |
| 22 | #include <linux/cdev.h> |
| 23 | |
Mauro Carvalho Chehab | a087ce7 | 2016-04-27 19:28:26 -0300 | [diff] [blame] | 24 | struct media_device; |
| 25 | |
Laurent Pinchart | cf4b921 | 2009-12-09 08:39:56 -0300 | [diff] [blame] | 26 | /* |
| 27 | * Flag to mark the media_devnode struct as registered. Drivers must not touch |
| 28 | * this flag directly, it will be set and cleared by media_devnode_register and |
| 29 | * media_devnode_unregister. |
| 30 | */ |
| 31 | #define MEDIA_FLAG_REGISTERED 0 |
| 32 | |
Mauro Carvalho Chehab | 75c7e29 | 2015-12-13 09:00:00 -0200 | [diff] [blame] | 33 | /** |
| 34 | * struct media_file_operations - Media device file operations |
| 35 | * |
| 36 | * @owner: should be filled with %THIS_MODULE |
| 37 | * @read: pointer to the function that implements read() syscall |
| 38 | * @write: pointer to the function that implements write() syscall |
| 39 | * @poll: pointer to the function that implements poll() syscall |
| 40 | * @ioctl: pointer to the function that implements ioctl() syscall |
| 41 | * @compat_ioctl: pointer to the function that will handle 32 bits userspace |
Randy Dunlap | f040e0f | 2020-07-15 00:05:50 +0200 | [diff] [blame] | 42 | * calls to the ioctl() syscall on a Kernel compiled with 64 bits. |
Mauro Carvalho Chehab | 75c7e29 | 2015-12-13 09:00:00 -0200 | [diff] [blame] | 43 | * @open: pointer to the function that implements open() syscall |
| 44 | * @release: pointer to the function that will release the resources allocated |
| 45 | * by the @open function. |
| 46 | */ |
Laurent Pinchart | cf4b921 | 2009-12-09 08:39:56 -0300 | [diff] [blame] | 47 | struct media_file_operations { |
| 48 | struct module *owner; |
| 49 | ssize_t (*read) (struct file *, char __user *, size_t, loff_t *); |
| 50 | ssize_t (*write) (struct file *, const char __user *, size_t, loff_t *); |
Al Viro | a3f8683 | 2017-07-02 22:22:01 -0400 | [diff] [blame] | 51 | __poll_t (*poll) (struct file *, struct poll_table_struct *); |
Laurent Pinchart | cf4b921 | 2009-12-09 08:39:56 -0300 | [diff] [blame] | 52 | long (*ioctl) (struct file *, unsigned int, unsigned long); |
Sakari Ailus | c6c1d50 | 2013-01-22 12:27:55 -0300 | [diff] [blame] | 53 | long (*compat_ioctl) (struct file *, unsigned int, unsigned long); |
Laurent Pinchart | cf4b921 | 2009-12-09 08:39:56 -0300 | [diff] [blame] | 54 | int (*open) (struct file *); |
| 55 | int (*release) (struct file *); |
| 56 | }; |
| 57 | |
| 58 | /** |
| 59 | * struct media_devnode - Media device node |
Mauro Carvalho Chehab | 0db5c79 | 2016-06-16 08:04:40 -0300 | [diff] [blame] | 60 | * @media_dev: pointer to struct &media_device |
Mauro Carvalho Chehab | 75c7e29 | 2015-12-13 09:00:00 -0200 | [diff] [blame] | 61 | * @fops: pointer to struct &media_file_operations with media device ops |
Mauro Carvalho Chehab | 0db5c79 | 2016-06-16 08:04:40 -0300 | [diff] [blame] | 62 | * @dev: pointer to struct &device containing the media controller device |
Mauro Carvalho Chehab | ec0255c | 2015-08-22 04:45:03 -0300 | [diff] [blame] | 63 | * @cdev: struct cdev pointer character device |
Laurent Pinchart | cf4b921 | 2009-12-09 08:39:56 -0300 | [diff] [blame] | 64 | * @parent: parent device |
| 65 | * @minor: device node minor number |
Mauro Carvalho Chehab | 48a7c4b | 2016-08-29 16:09:11 -0300 | [diff] [blame] | 66 | * @flags: flags, combination of the ``MEDIA_FLAG_*`` constants |
Mauro Carvalho Chehab | 82631b5 | 2016-09-08 09:57:24 -0300 | [diff] [blame] | 67 | * @release: release callback called at the end of ``media_devnode_release()`` |
| 68 | * routine at media-device.c. |
Laurent Pinchart | cf4b921 | 2009-12-09 08:39:56 -0300 | [diff] [blame] | 69 | * |
| 70 | * This structure represents a media-related device node. |
| 71 | * |
| 72 | * The @parent is a physical device. It must be set by core or device drivers |
| 73 | * before registering the node. |
| 74 | */ |
| 75 | struct media_devnode { |
Mauro Carvalho Chehab | a087ce7 | 2016-04-27 19:28:26 -0300 | [diff] [blame] | 76 | struct media_device *media_dev; |
| 77 | |
Laurent Pinchart | cf4b921 | 2009-12-09 08:39:56 -0300 | [diff] [blame] | 78 | /* device ops */ |
| 79 | const struct media_file_operations *fops; |
| 80 | |
| 81 | /* sysfs */ |
| 82 | struct device dev; /* media device */ |
| 83 | struct cdev cdev; /* character device */ |
| 84 | struct device *parent; /* device parent */ |
| 85 | |
| 86 | /* device info */ |
| 87 | int minor; |
| 88 | unsigned long flags; /* Use bitops to access flags */ |
| 89 | |
| 90 | /* callbacks */ |
Mauro Carvalho Chehab | 163f1e9 | 2016-03-23 11:22:57 -0300 | [diff] [blame] | 91 | void (*release)(struct media_devnode *devnode); |
Laurent Pinchart | cf4b921 | 2009-12-09 08:39:56 -0300 | [diff] [blame] | 92 | }; |
| 93 | |
| 94 | /* dev to media_devnode */ |
| 95 | #define to_media_devnode(cd) container_of(cd, struct media_devnode, dev) |
| 96 | |
Mauro Carvalho Chehab | fe3c565 | 2015-12-13 08:40:45 -0200 | [diff] [blame] | 97 | /** |
| 98 | * media_devnode_register - register a media device node |
| 99 | * |
Mauro Carvalho Chehab | 0db5c79 | 2016-06-16 08:04:40 -0300 | [diff] [blame] | 100 | * @mdev: struct media_device we want to register a device node |
Mauro Carvalho Chehab | 163f1e9 | 2016-03-23 11:22:57 -0300 | [diff] [blame] | 101 | * @devnode: media device node structure we want to register |
Mauro Carvalho Chehab | fe3c565 | 2015-12-13 08:40:45 -0200 | [diff] [blame] | 102 | * @owner: should be filled with %THIS_MODULE |
| 103 | * |
| 104 | * The registration code assigns minor numbers and registers the new device node |
| 105 | * with the kernel. An error is returned if no free minor number can be found, |
| 106 | * or if the registration of the device node fails. |
| 107 | * |
| 108 | * Zero is returned on success. |
| 109 | * |
| 110 | * Note that if the media_devnode_register call fails, the release() callback of |
| 111 | * the media_devnode structure is *not* called, so the caller is responsible for |
| 112 | * freeing any data. |
| 113 | */ |
Mauro Carvalho Chehab | a087ce7 | 2016-04-27 19:28:26 -0300 | [diff] [blame] | 114 | int __must_check media_devnode_register(struct media_device *mdev, |
| 115 | struct media_devnode *devnode, |
Sakari Ailus | 85de721 | 2013-12-12 12:38:17 -0300 | [diff] [blame] | 116 | struct module *owner); |
Mauro Carvalho Chehab | fe3c565 | 2015-12-13 08:40:45 -0200 | [diff] [blame] | 117 | |
| 118 | /** |
Shuah Khan | 6f0dd24 | 2016-06-10 14:37:23 -0300 | [diff] [blame] | 119 | * media_devnode_unregister_prepare - clear the media device node register bit |
| 120 | * @devnode: the device node to prepare for unregister |
| 121 | * |
| 122 | * This clears the passed device register bit. Future open calls will be met |
| 123 | * with errors. Should be called before media_devnode_unregister() to avoid |
| 124 | * races with unregister and device file open calls. |
| 125 | * |
| 126 | * This function can safely be called if the device node has never been |
| 127 | * registered or has already been unregistered. |
| 128 | */ |
| 129 | void media_devnode_unregister_prepare(struct media_devnode *devnode); |
| 130 | |
| 131 | /** |
Mauro Carvalho Chehab | fe3c565 | 2015-12-13 08:40:45 -0200 | [diff] [blame] | 132 | * media_devnode_unregister - unregister a media device node |
Mauro Carvalho Chehab | 163f1e9 | 2016-03-23 11:22:57 -0300 | [diff] [blame] | 133 | * @devnode: the device node to unregister |
Mauro Carvalho Chehab | fe3c565 | 2015-12-13 08:40:45 -0200 | [diff] [blame] | 134 | * |
| 135 | * This unregisters the passed device. Future open calls will be met with |
| 136 | * errors. |
| 137 | * |
Shuah Khan | 6f0dd24 | 2016-06-10 14:37:23 -0300 | [diff] [blame] | 138 | * Should be called after media_devnode_unregister_prepare() |
Mauro Carvalho Chehab | fe3c565 | 2015-12-13 08:40:45 -0200 | [diff] [blame] | 139 | */ |
Mauro Carvalho Chehab | 163f1e9 | 2016-03-23 11:22:57 -0300 | [diff] [blame] | 140 | void media_devnode_unregister(struct media_devnode *devnode); |
Laurent Pinchart | cf4b921 | 2009-12-09 08:39:56 -0300 | [diff] [blame] | 141 | |
Mauro Carvalho Chehab | 75c7e29 | 2015-12-13 09:00:00 -0200 | [diff] [blame] | 142 | /** |
| 143 | * media_devnode_data - returns a pointer to the &media_devnode |
| 144 | * |
| 145 | * @filp: pointer to struct &file |
| 146 | */ |
Laurent Pinchart | cf4b921 | 2009-12-09 08:39:56 -0300 | [diff] [blame] | 147 | static inline struct media_devnode *media_devnode_data(struct file *filp) |
| 148 | { |
| 149 | return filp->private_data; |
| 150 | } |
| 151 | |
Mauro Carvalho Chehab | 75c7e29 | 2015-12-13 09:00:00 -0200 | [diff] [blame] | 152 | /** |
| 153 | * media_devnode_is_registered - returns true if &media_devnode is registered; |
| 154 | * false otherwise. |
| 155 | * |
Mauro Carvalho Chehab | 163f1e9 | 2016-03-23 11:22:57 -0300 | [diff] [blame] | 156 | * @devnode: pointer to struct &media_devnode. |
Mauro Carvalho Chehab | a087ce7 | 2016-04-27 19:28:26 -0300 | [diff] [blame] | 157 | * |
| 158 | * Note: If mdev is NULL, it also returns false. |
Mauro Carvalho Chehab | 75c7e29 | 2015-12-13 09:00:00 -0200 | [diff] [blame] | 159 | */ |
Mauro Carvalho Chehab | 163f1e9 | 2016-03-23 11:22:57 -0300 | [diff] [blame] | 160 | static inline int media_devnode_is_registered(struct media_devnode *devnode) |
Laurent Pinchart | cf4b921 | 2009-12-09 08:39:56 -0300 | [diff] [blame] | 161 | { |
Mauro Carvalho Chehab | a087ce7 | 2016-04-27 19:28:26 -0300 | [diff] [blame] | 162 | if (!devnode) |
| 163 | return false; |
| 164 | |
Mauro Carvalho Chehab | 163f1e9 | 2016-03-23 11:22:57 -0300 | [diff] [blame] | 165 | return test_bit(MEDIA_FLAG_REGISTERED, &devnode->flags); |
Laurent Pinchart | cf4b921 | 2009-12-09 08:39:56 -0300 | [diff] [blame] | 166 | } |
| 167 | |
| 168 | #endif /* _MEDIA_DEVNODE_H */ |