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