1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3  * Media device
4  *
5  * Copyright (C) 2010 Nokia Corporation
6  *
7  * Contacts: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
8  *	     Sakari Ailus <sakari.ailus@iki.fi>
9  */
10 
11 #ifndef _MEDIA_DEVICE_H
12 #define _MEDIA_DEVICE_H
13 
14 #include <linux/list.h>
15 #include <linux/mutex.h>
16 
17 #include <media/media-devnode.h>
18 #include <media/media-entity.h>
19 
20 struct ida;
21 struct device;
22 struct media_device;
23 
24 /**
25  * struct media_entity_notify - Media Entity Notify
26  *
27  * @list: List head
28  * @notify_data: Input data to invoke the callback
29  * @notify: Callback function pointer
30  *
31  * Drivers may register a callback to take action when new entities get
32  * registered with the media device. This handler is intended for creating
33  * links between existing entities and should not create entities and register
34  * them.
35  */
36 struct media_entity_notify {
37 	struct list_head list;
38 	void *notify_data;
39 	void (*notify)(struct media_entity *entity, void *notify_data);
40 };
41 
42 /**
43  * struct media_device_ops - Media device operations
44  * @link_notify: Link state change notification callback. This callback is
45  *		 called with the graph_mutex held.
46  * @req_alloc: Allocate a request. Set this if you need to allocate a struct
47  *	       larger then struct media_request. @req_alloc and @req_free must
48  *	       either both be set or both be NULL.
49  * @req_free: Free a request. Set this if @req_alloc was set as well, leave
50  *	      to NULL otherwise.
51  * @req_validate: Validate a request, but do not queue yet. The req_queue_mutex
52  *	          lock is held when this op is called.
53  * @req_queue: Queue a validated request, cannot fail. If something goes
54  *	       wrong when queueing this request then it should be marked
55  *	       as such internally in the driver and any related buffers
56  *	       must eventually return to vb2 with state VB2_BUF_STATE_ERROR.
57  *	       The req_queue_mutex lock is held when this op is called.
58  *	       It is important that vb2 buffer objects are queued last after
59  *	       all other object types are queued: queueing a buffer kickstarts
60  *	       the request processing, so all other objects related to the
61  *	       request (and thus the buffer) must be available to the driver.
62  *	       And once a buffer is queued, then the driver can complete
63  *	       or delete objects from the request before req_queue exits.
64  */
65 struct media_device_ops {
66 	int (*link_notify)(struct media_link *link, u32 flags,
67 			   unsigned int notification);
68 	struct media_request *(*req_alloc)(struct media_device *mdev);
69 	void (*req_free)(struct media_request *req);
70 	int (*req_validate)(struct media_request *req);
71 	void (*req_queue)(struct media_request *req);
72 };
73 
74 /**
75  * struct media_device - Media device
76  * @dev:	Parent device
77  * @devnode:	Media device node
78  * @driver_name: Optional device driver name. If not set, calls to
79  *		%MEDIA_IOC_DEVICE_INFO will return ``dev->driver->name``.
80  *		This is needed for USB drivers for example, as otherwise
81  *		they'll all appear as if the driver name was "usb".
82  * @model:	Device model name
83  * @serial:	Device serial number (optional)
84  * @bus_info:	Unique and stable device location identifier
85  * @hw_revision: Hardware device revision
86  * @topology_version: Monotonic counter for storing the version of the graph
87  *		topology. Should be incremented each time the topology changes.
88  * @id:		Unique ID used on the last registered graph object
89  * @entity_internal_idx: Unique internal entity ID used by the graph traversal
90  *		algorithms
91  * @entity_internal_idx_max: Allocated internal entity indices
92  * @entities:	List of registered entities
93  * @interfaces:	List of registered interfaces
94  * @pads:	List of registered pads
95  * @links:	List of registered links
96  * @entity_notify: List of registered entity_notify callbacks
97  * @graph_mutex: Protects access to struct media_device data
98  * @pm_count_walk: Graph walk for power state walk. Access serialised using
99  *		   graph_mutex.
100  *
101  * @source_priv: Driver Private data for enable/disable source handlers
102  * @enable_source: Enable Source Handler function pointer
103  * @disable_source: Disable Source Handler function pointer
104  *
105  * @ops:	Operation handler callbacks
106  * @req_queue_mutex: Serialise the MEDIA_REQUEST_IOC_QUEUE ioctl w.r.t.
107  *		     other operations that stop or start streaming.
108  * @request_id: Used to generate unique request IDs
109  *
110  * This structure represents an abstract high-level media device. It allows easy
111  * access to entities and provides basic media device-level support. The
112  * structure can be allocated directly or embedded in a larger structure.
113  *
114  * The parent @dev is a physical device. It must be set before registering the
115  * media device.
116  *
117  * @model is a descriptive model name exported through sysfs. It doesn't have to
118  * be unique.
119  *
120  * @enable_source is a handler to find source entity for the
121  * sink entity  and activate the link between them if source
122  * entity is free. Drivers should call this handler before
123  * accessing the source.
124  *
125  * @disable_source is a handler to find source entity for the
126  * sink entity  and deactivate the link between them. Drivers
127  * should call this handler to release the source.
128  *
129  * Use-case: find tuner entity connected to the decoder
130  * entity and check if it is available, and activate the
131  * link between them from @enable_source and deactivate
132  * from @disable_source.
133  *
134  * .. note::
135  *
136  *    Bridge driver is expected to implement and set the
137  *    handler when &media_device is registered or when
138  *    bridge driver finds the media_device during probe.
139  *    Bridge driver sets source_priv with information
140  *    necessary to run @enable_source and @disable_source handlers.
141  *    Callers should hold graph_mutex to access and call @enable_source
142  *    and @disable_source handlers.
143  */
144 struct media_device {
145 	/* dev->driver_data points to this struct. */
146 	struct device *dev;
147 	struct media_devnode *devnode;
148 
149 	char model[32];
150 	char driver_name[32];
151 	char serial[40];
152 	char bus_info[32];
153 	u32 hw_revision;
154 
155 	u64 topology_version;
156 
157 	u32 id;
158 	struct ida entity_internal_idx;
159 	int entity_internal_idx_max;
160 
161 	struct list_head entities;
162 	struct list_head interfaces;
163 	struct list_head pads;
164 	struct list_head links;
165 
166 	/* notify callback list invoked when a new entity is registered */
167 	struct list_head entity_notify;
168 
169 	/* Serializes graph operations. */
170 	struct mutex graph_mutex;
171 	struct media_graph pm_count_walk;
172 
173 	void *source_priv;
174 	int (*enable_source)(struct media_entity *entity,
175 			     struct media_pipeline *pipe);
176 	void (*disable_source)(struct media_entity *entity);
177 
178 	const struct media_device_ops *ops;
179 
180 	struct mutex req_queue_mutex;
181 	atomic_t request_id;
182 };
183 
184 /* We don't need to include pci.h or usb.h here */
185 struct pci_dev;
186 struct usb_device;
187 
188 #ifdef CONFIG_MEDIA_CONTROLLER
189 
190 /* Supported link_notify @notification values. */
191 #define MEDIA_DEV_NOTIFY_PRE_LINK_CH	0
192 #define MEDIA_DEV_NOTIFY_POST_LINK_CH	1
193 
194 /**
195  * media_entity_enum_init - Initialise an entity enumeration
196  *
197  * @ent_enum: Entity enumeration to be initialised
198  * @mdev: The related media device
199  *
200  * Return: zero on success or a negative error code.
201  */
media_entity_enum_init(struct media_entity_enum * ent_enum,struct media_device * mdev)202 static inline __must_check int media_entity_enum_init(
203 	struct media_entity_enum *ent_enum, struct media_device *mdev)
204 {
205 	return __media_entity_enum_init(ent_enum,
206 					mdev->entity_internal_idx_max + 1);
207 }
208 
209 /**
210  * media_device_init() - Initializes a media device element
211  *
212  * @mdev:	pointer to struct &media_device
213  *
214  * This function initializes the media device prior to its registration.
215  * The media device initialization and registration is split in two functions
216  * to avoid race conditions and make the media device available to user-space
217  * before the media graph has been completed.
218  *
219  * So drivers need to first initialize the media device, register any entity
220  * within the media device, create pad to pad links and then finally register
221  * the media device by calling media_device_register() as a final step.
222  */
223 void media_device_init(struct media_device *mdev);
224 
225 /**
226  * media_device_cleanup() - Cleanups a media device element
227  *
228  * @mdev:	pointer to struct &media_device
229  *
230  * This function that will destroy the graph_mutex that is
231  * initialized in media_device_init().
232  */
233 void media_device_cleanup(struct media_device *mdev);
234 
235 /**
236  * __media_device_register() - Registers a media device element
237  *
238  * @mdev:	pointer to struct &media_device
239  * @owner:	should be filled with %THIS_MODULE
240  *
241  * Users, should, instead, call the media_device_register() macro.
242  *
243  * The caller is responsible for initializing the &media_device structure
244  * before registration. The following fields of &media_device must be set:
245  *
246  *  - &media_entity.dev must point to the parent device (usually a &pci_dev,
247  *    &usb_interface or &platform_device instance).
248  *
249  *  - &media_entity.model must be filled with the device model name as a
250  *    NUL-terminated UTF-8 string. The device/model revision must not be
251  *    stored in this field.
252  *
253  * The following fields are optional:
254  *
255  *  - &media_entity.serial is a unique serial number stored as a
256  *    NUL-terminated ASCII string. The field is big enough to store a GUID
257  *    in text form. If the hardware doesn't provide a unique serial number
258  *    this field must be left empty.
259  *
260  *  - &media_entity.bus_info represents the location of the device in the
261  *    system as a NUL-terminated ASCII string. For PCI/PCIe devices
262  *    &media_entity.bus_info must be set to "PCI:" (or "PCIe:") followed by
263  *    the value of pci_name(). For USB devices,the usb_make_path() function
264  *    must be used. This field is used by applications to distinguish between
265  *    otherwise identical devices that don't provide a serial number.
266  *
267  *  - &media_entity.hw_revision is the hardware device revision in a
268  *    driver-specific format. When possible the revision should be formatted
269  *    with the KERNEL_VERSION() macro.
270  *
271  * .. note::
272  *
273  *    #) Upon successful registration a character device named media[0-9]+ is created. The device major and minor numbers are dynamic. The model name is exported as a sysfs attribute.
274  *
275  *    #) Unregistering a media device that hasn't been registered is **NOT** safe.
276  *
277  * Return: returns zero on success or a negative error code.
278  */
279 int __must_check __media_device_register(struct media_device *mdev,
280 					 struct module *owner);
281 
282 
283 /**
284  * media_device_register() - Registers a media device element
285  *
286  * @mdev:	pointer to struct &media_device
287  *
288  * This macro calls __media_device_register() passing %THIS_MODULE as
289  * the __media_device_register() second argument (**owner**).
290  */
291 #define media_device_register(mdev) __media_device_register(mdev, THIS_MODULE)
292 
293 /**
294  * media_device_unregister() - Unregisters a media device element
295  *
296  * @mdev:	pointer to struct &media_device
297  *
298  * It is safe to call this function on an unregistered (but initialised)
299  * media device.
300  */
301 void media_device_unregister(struct media_device *mdev);
302 
303 /**
304  * media_device_register_entity() - registers a media entity inside a
305  *	previously registered media device.
306  *
307  * @mdev:	pointer to struct &media_device
308  * @entity:	pointer to struct &media_entity to be registered
309  *
310  * Entities are identified by a unique positive integer ID. The media
311  * controller framework will such ID automatically. IDs are not guaranteed
312  * to be contiguous, and the ID number can change on newer Kernel versions.
313  * So, neither the driver nor userspace should hardcode ID numbers to refer
314  * to the entities, but, instead, use the framework to find the ID, when
315  * needed.
316  *
317  * The media_entity name, type and flags fields should be initialized before
318  * calling media_device_register_entity(). Entities embedded in higher-level
319  * standard structures can have some of those fields set by the higher-level
320  * framework.
321  *
322  * If the device has pads, media_entity_pads_init() should be called before
323  * this function. Otherwise, the &media_entity.pad and &media_entity.num_pads
324  * should be zeroed before calling this function.
325  *
326  * Entities have flags that describe the entity capabilities and state:
327  *
328  * %MEDIA_ENT_FL_DEFAULT
329  *    indicates the default entity for a given type.
330  *    This can be used to report the default audio and video devices or the
331  *    default camera sensor.
332  *
333  * .. note::
334  *
335  *    Drivers should set the entity function before calling this function.
336  *    Please notice that the values %MEDIA_ENT_F_V4L2_SUBDEV_UNKNOWN and
337  *    %MEDIA_ENT_F_UNKNOWN should not be used by the drivers.
338  */
339 int __must_check media_device_register_entity(struct media_device *mdev,
340 					      struct media_entity *entity);
341 
342 /**
343  * media_device_unregister_entity() - unregisters a media entity.
344  *
345  * @entity:	pointer to struct &media_entity to be unregistered
346  *
347  * All links associated with the entity and all PADs are automatically
348  * unregistered from the media_device when this function is called.
349  *
350  * Unregistering an entity will not change the IDs of the other entities and
351  * the previoully used ID will never be reused for a newly registered entities.
352  *
353  * When a media device is unregistered, all its entities are unregistered
354  * automatically. No manual entities unregistration is then required.
355  *
356  * .. note::
357  *
358  *    The media_entity instance itself must be freed explicitly by
359  *    the driver if required.
360  */
361 void media_device_unregister_entity(struct media_entity *entity);
362 
363 /**
364  * media_device_register_entity_notify() - Registers a media entity_notify
365  *					   callback
366  *
367  * @mdev:      The media device
368  * @nptr:      The media_entity_notify
369  *
370  * .. note::
371  *
372  *    When a new entity is registered, all the registered
373  *    media_entity_notify callbacks are invoked.
374  */
375 
376 int __must_check media_device_register_entity_notify(struct media_device *mdev,
377 					struct media_entity_notify *nptr);
378 
379 /**
380  * media_device_unregister_entity_notify() - Unregister a media entity notify
381  *					     callback
382  *
383  * @mdev:      The media device
384  * @nptr:      The media_entity_notify
385  *
386  */
387 void media_device_unregister_entity_notify(struct media_device *mdev,
388 					struct media_entity_notify *nptr);
389 
390 /* Iterate over all entities. */
391 #define media_device_for_each_entity(entity, mdev)			\
392 	list_for_each_entry(entity, &(mdev)->entities, graph_obj.list)
393 
394 /* Iterate over all interfaces. */
395 #define media_device_for_each_intf(intf, mdev)			\
396 	list_for_each_entry(intf, &(mdev)->interfaces, graph_obj.list)
397 
398 /* Iterate over all pads. */
399 #define media_device_for_each_pad(pad, mdev)			\
400 	list_for_each_entry(pad, &(mdev)->pads, graph_obj.list)
401 
402 /* Iterate over all links. */
403 #define media_device_for_each_link(link, mdev)			\
404 	list_for_each_entry(link, &(mdev)->links, graph_obj.list)
405 
406 /**
407  * media_device_pci_init() - create and initialize a
408  *	struct &media_device from a PCI device.
409  *
410  * @mdev:	pointer to struct &media_device
411  * @pci_dev:	pointer to struct pci_dev
412  * @name:	media device name. If %NULL, the routine will use the default
413  *		name for the pci device, given by pci_name() macro.
414  */
415 void media_device_pci_init(struct media_device *mdev,
416 			   struct pci_dev *pci_dev,
417 			   const char *name);
418 /**
419  * __media_device_usb_init() - create and initialize a
420  *	struct &media_device from a PCI device.
421  *
422  * @mdev:	pointer to struct &media_device
423  * @udev:	pointer to struct usb_device
424  * @board_name:	media device name. If %NULL, the routine will use the usb
425  *		product name, if available.
426  * @driver_name: name of the driver. if %NULL, the routine will use the name
427  *		given by ``udev->dev->driver->name``, with is usually the wrong
428  *		thing to do.
429  *
430  * .. note::
431  *
432  *    It is better to call media_device_usb_init() instead, as
433  *    such macro fills driver_name with %KBUILD_MODNAME.
434  */
435 void __media_device_usb_init(struct media_device *mdev,
436 			     struct usb_device *udev,
437 			     const char *board_name,
438 			     const char *driver_name);
439 
440 #else
media_device_register(struct media_device * mdev)441 static inline int media_device_register(struct media_device *mdev)
442 {
443 	return 0;
444 }
media_device_unregister(struct media_device * mdev)445 static inline void media_device_unregister(struct media_device *mdev)
446 {
447 }
media_device_register_entity(struct media_device * mdev,struct media_entity * entity)448 static inline int media_device_register_entity(struct media_device *mdev,
449 						struct media_entity *entity)
450 {
451 	return 0;
452 }
media_device_unregister_entity(struct media_entity * entity)453 static inline void media_device_unregister_entity(struct media_entity *entity)
454 {
455 }
media_device_register_entity_notify(struct media_device * mdev,struct media_entity_notify * nptr)456 static inline int media_device_register_entity_notify(
457 					struct media_device *mdev,
458 					struct media_entity_notify *nptr)
459 {
460 	return 0;
461 }
media_device_unregister_entity_notify(struct media_device * mdev,struct media_entity_notify * nptr)462 static inline void media_device_unregister_entity_notify(
463 					struct media_device *mdev,
464 					struct media_entity_notify *nptr)
465 {
466 }
467 
media_device_pci_init(struct media_device * mdev,struct pci_dev * pci_dev,char * name)468 static inline void media_device_pci_init(struct media_device *mdev,
469 					 struct pci_dev *pci_dev,
470 					 char *name)
471 {
472 }
473 
__media_device_usb_init(struct media_device * mdev,struct usb_device * udev,char * board_name,char * driver_name)474 static inline void __media_device_usb_init(struct media_device *mdev,
475 					   struct usb_device *udev,
476 					   char *board_name,
477 					   char *driver_name)
478 {
479 }
480 
481 #endif /* CONFIG_MEDIA_CONTROLLER */
482 
483 /**
484  * media_device_usb_init() - create and initialize a
485  *	struct &media_device from a PCI device.
486  *
487  * @mdev:	pointer to struct &media_device
488  * @udev:	pointer to struct usb_device
489  * @name:	media device name. If %NULL, the routine will use the usb
490  *		product name, if available.
491  *
492  * This macro calls media_device_usb_init() passing the
493  * media_device_usb_init() **driver_name** parameter filled with
494  * %KBUILD_MODNAME.
495  */
496 #define media_device_usb_init(mdev, udev, name) \
497 	__media_device_usb_init(mdev, udev, name, KBUILD_MODNAME)
498 
499 #endif
500