xref: /openbmc/linux/include/media/v4l2-fwnode.h (revision 6c33a6f4)
1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3  * V4L2 fwnode binding parsing library
4  *
5  * Copyright (c) 2016 Intel Corporation.
6  * Author: Sakari Ailus <sakari.ailus@linux.intel.com>
7  *
8  * Copyright (C) 2012 - 2013 Samsung Electronics Co., Ltd.
9  * Author: Sylwester Nawrocki <s.nawrocki@samsung.com>
10  *
11  * Copyright (C) 2012 Renesas Electronics Corp.
12  * Author: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
13  */
14 #ifndef _V4L2_FWNODE_H
15 #define _V4L2_FWNODE_H
16 
17 #include <linux/errno.h>
18 #include <linux/fwnode.h>
19 #include <linux/list.h>
20 #include <linux/types.h>
21 
22 #include <media/v4l2-mediabus.h>
23 #include <media/v4l2-subdev.h>
24 
25 struct fwnode_handle;
26 struct v4l2_async_notifier;
27 struct v4l2_async_subdev;
28 
29 #define V4L2_FWNODE_CSI2_MAX_DATA_LANES	4
30 
31 /**
32  * struct v4l2_fwnode_bus_mipi_csi2 - MIPI CSI-2 bus data structure
33  * @flags: media bus (V4L2_MBUS_*) flags
34  * @data_lanes: an array of physical data lane indexes
35  * @clock_lane: physical lane index of the clock lane
36  * @num_data_lanes: number of data lanes
37  * @lane_polarities: polarity of the lanes. The order is the same of
38  *		   the physical lanes.
39  */
40 struct v4l2_fwnode_bus_mipi_csi2 {
41 	unsigned int flags;
42 	unsigned char data_lanes[V4L2_FWNODE_CSI2_MAX_DATA_LANES];
43 	unsigned char clock_lane;
44 	unsigned short num_data_lanes;
45 	bool lane_polarities[1 + V4L2_FWNODE_CSI2_MAX_DATA_LANES];
46 };
47 
48 /**
49  * struct v4l2_fwnode_bus_parallel - parallel data bus data structure
50  * @flags: media bus (V4L2_MBUS_*) flags
51  * @bus_width: bus width in bits
52  * @data_shift: data shift in bits
53  */
54 struct v4l2_fwnode_bus_parallel {
55 	unsigned int flags;
56 	unsigned char bus_width;
57 	unsigned char data_shift;
58 };
59 
60 /**
61  * struct v4l2_fwnode_bus_mipi_csi1 - CSI-1/CCP2 data bus structure
62  * @clock_inv: polarity of clock/strobe signal
63  *	       false - not inverted, true - inverted
64  * @strobe: false - data/clock, true - data/strobe
65  * @lane_polarity: the polarities of the clock (index 0) and data lanes
66  *		   index (1)
67  * @data_lane: the number of the data lane
68  * @clock_lane: the number of the clock lane
69  */
70 struct v4l2_fwnode_bus_mipi_csi1 {
71 	unsigned char clock_inv:1;
72 	unsigned char strobe:1;
73 	bool lane_polarity[2];
74 	unsigned char data_lane;
75 	unsigned char clock_lane;
76 };
77 
78 /**
79  * struct v4l2_fwnode_endpoint - the endpoint data structure
80  * @base: fwnode endpoint of the v4l2_fwnode
81  * @bus_type: bus type
82  * @bus: union with bus configuration data structure
83  * @bus.parallel: embedded &struct v4l2_fwnode_bus_parallel.
84  *		  Used if the bus is parallel.
85  * @bus.mipi_csi1: embedded &struct v4l2_fwnode_bus_mipi_csi1.
86  *		   Used if the bus is MIPI Alliance's Camera Serial
87  *		   Interface version 1 (MIPI CSI1) or Standard
88  *		   Mobile Imaging Architecture's Compact Camera Port 2
89  *		   (SMIA CCP2).
90  * @bus.mipi_csi2: embedded &struct v4l2_fwnode_bus_mipi_csi2.
91  *		   Used if the bus is MIPI Alliance's Camera Serial
92  *		   Interface version 2 (MIPI CSI2).
93  * @link_frequencies: array of supported link frequencies
94  * @nr_of_link_frequencies: number of elements in link_frequenccies array
95  */
96 struct v4l2_fwnode_endpoint {
97 	struct fwnode_endpoint base;
98 	/*
99 	 * Fields below this line will be zeroed by
100 	 * v4l2_fwnode_endpoint_parse()
101 	 */
102 	enum v4l2_mbus_type bus_type;
103 	union {
104 		struct v4l2_fwnode_bus_parallel parallel;
105 		struct v4l2_fwnode_bus_mipi_csi1 mipi_csi1;
106 		struct v4l2_fwnode_bus_mipi_csi2 mipi_csi2;
107 	} bus;
108 	u64 *link_frequencies;
109 	unsigned int nr_of_link_frequencies;
110 };
111 
112 /**
113  * struct v4l2_fwnode_link - a link between two endpoints
114  * @local_node: pointer to device_node of this endpoint
115  * @local_port: identifier of the port this endpoint belongs to
116  * @remote_node: pointer to device_node of the remote endpoint
117  * @remote_port: identifier of the port the remote endpoint belongs to
118  */
119 struct v4l2_fwnode_link {
120 	struct fwnode_handle *local_node;
121 	unsigned int local_port;
122 	struct fwnode_handle *remote_node;
123 	unsigned int remote_port;
124 };
125 
126 /**
127  * v4l2_fwnode_endpoint_parse() - parse all fwnode node properties
128  * @fwnode: pointer to the endpoint's fwnode handle
129  * @vep: pointer to the V4L2 fwnode data structure
130  *
131  * This function parses the V4L2 fwnode endpoint specific parameters from the
132  * firmware. The caller is responsible for assigning @vep.bus_type to a valid
133  * media bus type. The caller may also set the default configuration for the
134  * endpoint --- a configuration that shall be in line with the DT binding
135  * documentation. Should a device support multiple bus types, the caller may
136  * call this function once the correct type is found --- with a default
137  * configuration valid for that type.
138  *
139  * As a compatibility means guessing the bus type is also supported by setting
140  * @vep.bus_type to V4L2_MBUS_UNKNOWN. The caller may not provide a default
141  * configuration in this case as the defaults are specific to a given bus type.
142  * This functionality is deprecated and should not be used in new drivers and it
143  * is only supported for CSI-2 D-PHY, parallel and Bt.656 buses.
144  *
145  * The function does not change the V4L2 fwnode endpoint state if it fails.
146  *
147  * NOTE: This function does not parse properties the size of which is variable
148  * without a low fixed limit. Please use v4l2_fwnode_endpoint_alloc_parse() in
149  * new drivers instead.
150  *
151  * Return: %0 on success or a negative error code on failure:
152  *	   %-ENOMEM on memory allocation failure
153  *	   %-EINVAL on parsing failure
154  *	   %-ENXIO on mismatching bus types
155  */
156 int v4l2_fwnode_endpoint_parse(struct fwnode_handle *fwnode,
157 			       struct v4l2_fwnode_endpoint *vep);
158 
159 /**
160  * v4l2_fwnode_endpoint_free() - free the V4L2 fwnode acquired by
161  * v4l2_fwnode_endpoint_alloc_parse()
162  * @vep: the V4L2 fwnode the resources of which are to be released
163  *
164  * It is safe to call this function with NULL argument or on a V4L2 fwnode the
165  * parsing of which failed.
166  */
167 void v4l2_fwnode_endpoint_free(struct v4l2_fwnode_endpoint *vep);
168 
169 /**
170  * v4l2_fwnode_endpoint_alloc_parse() - parse all fwnode node properties
171  * @fwnode: pointer to the endpoint's fwnode handle
172  * @vep: pointer to the V4L2 fwnode data structure
173  *
174  * This function parses the V4L2 fwnode endpoint specific parameters from the
175  * firmware. The caller is responsible for assigning @vep.bus_type to a valid
176  * media bus type. The caller may also set the default configuration for the
177  * endpoint --- a configuration that shall be in line with the DT binding
178  * documentation. Should a device support multiple bus types, the caller may
179  * call this function once the correct type is found --- with a default
180  * configuration valid for that type.
181  *
182  * As a compatibility means guessing the bus type is also supported by setting
183  * @vep.bus_type to V4L2_MBUS_UNKNOWN. The caller may not provide a default
184  * configuration in this case as the defaults are specific to a given bus type.
185  * This functionality is deprecated and should not be used in new drivers and it
186  * is only supported for CSI-2 D-PHY, parallel and Bt.656 buses.
187  *
188  * The function does not change the V4L2 fwnode endpoint state if it fails.
189  *
190  * v4l2_fwnode_endpoint_alloc_parse() has two important differences to
191  * v4l2_fwnode_endpoint_parse():
192  *
193  * 1. It also parses variable size data.
194  *
195  * 2. The memory it has allocated to store the variable size data must be freed
196  *    using v4l2_fwnode_endpoint_free() when no longer needed.
197  *
198  * Return: %0 on success or a negative error code on failure:
199  *	   %-ENOMEM on memory allocation failure
200  *	   %-EINVAL on parsing failure
201  *	   %-ENXIO on mismatching bus types
202  */
203 int v4l2_fwnode_endpoint_alloc_parse(struct fwnode_handle *fwnode,
204 				     struct v4l2_fwnode_endpoint *vep);
205 
206 /**
207  * v4l2_fwnode_parse_link() - parse a link between two endpoints
208  * @fwnode: pointer to the endpoint's fwnode at the local end of the link
209  * @link: pointer to the V4L2 fwnode link data structure
210  *
211  * Fill the link structure with the local and remote nodes and port numbers.
212  * The local_node and remote_node fields are set to point to the local and
213  * remote port's parent nodes respectively (the port parent node being the
214  * parent node of the port node if that node isn't a 'ports' node, or the
215  * grand-parent node of the port node otherwise).
216  *
217  * A reference is taken to both the local and remote nodes, the caller must use
218  * v4l2_fwnode_put_link() to drop the references when done with the
219  * link.
220  *
221  * Return: 0 on success, or -ENOLINK if the remote endpoint fwnode can't be
222  * found.
223  */
224 int v4l2_fwnode_parse_link(struct fwnode_handle *fwnode,
225 			   struct v4l2_fwnode_link *link);
226 
227 /**
228  * v4l2_fwnode_put_link() - drop references to nodes in a link
229  * @link: pointer to the V4L2 fwnode link data structure
230  *
231  * Drop references to the local and remote nodes in the link. This function
232  * must be called on every link parsed with v4l2_fwnode_parse_link().
233  */
234 void v4l2_fwnode_put_link(struct v4l2_fwnode_link *link);
235 
236 /**
237  * typedef parse_endpoint_func - Driver's callback function to be called on
238  *	each V4L2 fwnode endpoint.
239  *
240  * @dev: pointer to &struct device
241  * @vep: pointer to &struct v4l2_fwnode_endpoint
242  * @asd: pointer to &struct v4l2_async_subdev
243  *
244  * Return:
245  * * %0 on success
246  * * %-ENOTCONN if the endpoint is to be skipped but this
247  *   should not be considered as an error
248  * * %-EINVAL if the endpoint configuration is invalid
249  */
250 typedef int (*parse_endpoint_func)(struct device *dev,
251 				  struct v4l2_fwnode_endpoint *vep,
252 				  struct v4l2_async_subdev *asd);
253 
254 /**
255  * v4l2_async_notifier_parse_fwnode_endpoints - Parse V4L2 fwnode endpoints in a
256  *						device node
257  * @dev: the device the endpoints of which are to be parsed
258  * @notifier: notifier for @dev
259  * @asd_struct_size: size of the driver's async sub-device struct, including
260  *		     sizeof(struct v4l2_async_subdev). The &struct
261  *		     v4l2_async_subdev shall be the first member of
262  *		     the driver's async sub-device struct, i.e. both
263  *		     begin at the same memory address.
264  * @parse_endpoint: Driver's callback function called on each V4L2 fwnode
265  *		    endpoint. Optional.
266  *
267  * Parse the fwnode endpoints of the @dev device and populate the async sub-
268  * devices list in the notifier. The @parse_endpoint callback function is
269  * called for each endpoint with the corresponding async sub-device pointer to
270  * let the caller initialize the driver-specific part of the async sub-device
271  * structure.
272  *
273  * The notifier memory shall be zeroed before this function is called on the
274  * notifier.
275  *
276  * This function may not be called on a registered notifier and may be called on
277  * a notifier only once.
278  *
279  * The &struct v4l2_fwnode_endpoint passed to the callback function
280  * @parse_endpoint is released once the function is finished. If there is a need
281  * to retain that configuration, the user needs to allocate memory for it.
282  *
283  * Any notifier populated using this function must be released with a call to
284  * v4l2_async_notifier_cleanup() after it has been unregistered and the async
285  * sub-devices are no longer in use, even if the function returned an error.
286  *
287  * Return: %0 on success, including when no async sub-devices are found
288  *	   %-ENOMEM if memory allocation failed
289  *	   %-EINVAL if graph or endpoint parsing failed
290  *	   Other error codes as returned by @parse_endpoint
291  */
292 int
293 v4l2_async_notifier_parse_fwnode_endpoints(struct device *dev,
294 					   struct v4l2_async_notifier *notifier,
295 					   size_t asd_struct_size,
296 					   parse_endpoint_func parse_endpoint);
297 
298 /**
299  * v4l2_async_notifier_parse_fwnode_endpoints_by_port - Parse V4L2 fwnode
300  *							endpoints of a port in a
301  *							device node
302  * @dev: the device the endpoints of which are to be parsed
303  * @notifier: notifier for @dev
304  * @asd_struct_size: size of the driver's async sub-device struct, including
305  *		     sizeof(struct v4l2_async_subdev). The &struct
306  *		     v4l2_async_subdev shall be the first member of
307  *		     the driver's async sub-device struct, i.e. both
308  *		     begin at the same memory address.
309  * @port: port number where endpoints are to be parsed
310  * @parse_endpoint: Driver's callback function called on each V4L2 fwnode
311  *		    endpoint. Optional.
312  *
313  * This function is just like v4l2_async_notifier_parse_fwnode_endpoints() with
314  * the exception that it only parses endpoints in a given port. This is useful
315  * on devices that have both sinks and sources: the async sub-devices connected
316  * to sources have already been configured by another driver (on capture
317  * devices). In this case the driver must know which ports to parse.
318  *
319  * Parse the fwnode endpoints of the @dev device on a given @port and populate
320  * the async sub-devices list of the notifier. The @parse_endpoint callback
321  * function is called for each endpoint with the corresponding async sub-device
322  * pointer to let the caller initialize the driver-specific part of the async
323  * sub-device structure.
324  *
325  * The notifier memory shall be zeroed before this function is called on the
326  * notifier the first time.
327  *
328  * This function may not be called on a registered notifier and may be called on
329  * a notifier only once per port.
330  *
331  * The &struct v4l2_fwnode_endpoint passed to the callback function
332  * @parse_endpoint is released once the function is finished. If there is a need
333  * to retain that configuration, the user needs to allocate memory for it.
334  *
335  * Any notifier populated using this function must be released with a call to
336  * v4l2_async_notifier_cleanup() after it has been unregistered and the async
337  * sub-devices are no longer in use, even if the function returned an error.
338  *
339  * Return: %0 on success, including when no async sub-devices are found
340  *	   %-ENOMEM if memory allocation failed
341  *	   %-EINVAL if graph or endpoint parsing failed
342  *	   Other error codes as returned by @parse_endpoint
343  */
344 int
345 v4l2_async_notifier_parse_fwnode_endpoints_by_port(struct device *dev,
346 						   struct v4l2_async_notifier *notifier,
347 						   size_t asd_struct_size,
348 						   unsigned int port,
349 						   parse_endpoint_func parse_endpoint);
350 
351 /**
352  * v4l2_fwnode_reference_parse_sensor_common - parse common references on
353  *					       sensors for async sub-devices
354  * @dev: the device node the properties of which are parsed for references
355  * @notifier: the async notifier where the async subdevs will be added
356  *
357  * Parse common sensor properties for remote devices related to the
358  * sensor and set up async sub-devices for them.
359  *
360  * Any notifier populated using this function must be released with a call to
361  * v4l2_async_notifier_release() after it has been unregistered and the async
362  * sub-devices are no longer in use, even in the case the function returned an
363  * error.
364  *
365  * Return: 0 on success
366  *	   -ENOMEM if memory allocation failed
367  *	   -EINVAL if property parsing failed
368  */
369 int v4l2_async_notifier_parse_fwnode_sensor_common(struct device *dev,
370 						   struct v4l2_async_notifier *notifier);
371 
372 /**
373  * v4l2_async_register_fwnode_subdev - registers a sub-device to the
374  *					asynchronous sub-device framework
375  *					and parses fwnode endpoints
376  *
377  * @sd: pointer to struct &v4l2_subdev
378  * @asd_struct_size: size of the driver's async sub-device struct, including
379  *		     sizeof(struct v4l2_async_subdev). The &struct
380  *		     v4l2_async_subdev shall be the first member of
381  *		     the driver's async sub-device struct, i.e. both
382  *		     begin at the same memory address.
383  * @ports: array of port id's to parse for fwnode endpoints. If NULL, will
384  *	   parse all ports owned by the sub-device.
385  * @num_ports: number of ports in @ports array. Ignored if @ports is NULL.
386  * @parse_endpoint: Driver's callback function called on each V4L2 fwnode
387  *		    endpoint. Optional.
388  *
389  * This function is just like v4l2_async_register_subdev() with the
390  * exception that calling it will also allocate a notifier for the
391  * sub-device, parse the sub-device's firmware node endpoints using
392  * v4l2_async_notifier_parse_fwnode_endpoints() or
393  * v4l2_async_notifier_parse_fwnode_endpoints_by_port(), and
394  * registers the sub-device notifier. The sub-device is similarly
395  * unregistered by calling v4l2_async_unregister_subdev().
396  *
397  * While registered, the subdev module is marked as in-use.
398  *
399  * An error is returned if the module is no longer loaded on any attempts
400  * to register it.
401  */
402 int
403 v4l2_async_register_fwnode_subdev(struct v4l2_subdev *sd,
404 				  size_t asd_struct_size,
405 				  unsigned int *ports,
406 				  unsigned int num_ports,
407 				  parse_endpoint_func parse_endpoint);
408 
409 #endif /* _V4L2_FWNODE_H */
410