xref: /openbmc/linux/include/media/v4l2-fwnode.h (revision f32e5616)
1 /*
2  * V4L2 fwnode binding parsing library
3  *
4  * Copyright (c) 2016 Intel Corporation.
5  * Author: Sakari Ailus <sakari.ailus@linux.intel.com>
6  *
7  * Copyright (C) 2012 - 2013 Samsung Electronics Co., Ltd.
8  * Author: Sylwester Nawrocki <s.nawrocki@samsung.com>
9  *
10  * Copyright (C) 2012 Renesas Electronics Corp.
11  * Author: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
12  *
13  * This program is free software; you can redistribute it and/or modify
14  * it under the terms of version 2 of the GNU General Public License as
15  * published by the Free Software Foundation.
16  */
17 #ifndef _V4L2_FWNODE_H
18 #define _V4L2_FWNODE_H
19 
20 #include <linux/errno.h>
21 #include <linux/fwnode.h>
22 #include <linux/list.h>
23 #include <linux/types.h>
24 
25 #include <media/v4l2-mediabus.h>
26 #include <media/v4l2-subdev.h>
27 
28 struct fwnode_handle;
29 struct v4l2_async_notifier;
30 struct v4l2_async_subdev;
31 
32 #define V4L2_FWNODE_CSI2_MAX_DATA_LANES	4
33 
34 /**
35  * struct v4l2_fwnode_bus_mipi_csi2 - MIPI CSI-2 bus data structure
36  * @flags: media bus (V4L2_MBUS_*) flags
37  * @data_lanes: an array of physical data lane indexes
38  * @clock_lane: physical lane index of the clock lane
39  * @num_data_lanes: number of data lanes
40  * @lane_polarities: polarity of the lanes. The order is the same of
41  *		   the physical lanes.
42  */
43 struct v4l2_fwnode_bus_mipi_csi2 {
44 	unsigned int flags;
45 	unsigned char data_lanes[V4L2_FWNODE_CSI2_MAX_DATA_LANES];
46 	unsigned char clock_lane;
47 	unsigned short num_data_lanes;
48 	bool lane_polarities[1 + V4L2_FWNODE_CSI2_MAX_DATA_LANES];
49 };
50 
51 /**
52  * struct v4l2_fwnode_bus_parallel - parallel data bus data structure
53  * @flags: media bus (V4L2_MBUS_*) flags
54  * @bus_width: bus width in bits
55  * @data_shift: data shift in bits
56  */
57 struct v4l2_fwnode_bus_parallel {
58 	unsigned int flags;
59 	unsigned char bus_width;
60 	unsigned char data_shift;
61 };
62 
63 /**
64  * struct v4l2_fwnode_bus_mipi_csi1 - CSI-1/CCP2 data bus structure
65  * @clock_inv: polarity of clock/strobe signal
66  *	       false - not inverted, true - inverted
67  * @strobe: false - data/clock, true - data/strobe
68  * @lane_polarity: the polarities of the clock (index 0) and data lanes
69  *		   index (1)
70  * @data_lane: the number of the data lane
71  * @clock_lane: the number of the clock lane
72  */
73 struct v4l2_fwnode_bus_mipi_csi1 {
74 	unsigned char clock_inv:1;
75 	unsigned char strobe:1;
76 	bool lane_polarity[2];
77 	unsigned char data_lane;
78 	unsigned char clock_lane;
79 };
80 
81 /**
82  * struct v4l2_fwnode_endpoint - the endpoint data structure
83  * @base: fwnode endpoint of the v4l2_fwnode
84  * @bus_type: bus type
85  * @bus: union with bus configuration data structure
86  * @bus.parallel: embedded &struct v4l2_fwnode_bus_parallel.
87  *		  Used if the bus is parallel.
88  * @bus.mipi_csi1: embedded &struct v4l2_fwnode_bus_mipi_csi1.
89  *		   Used if the bus is MIPI Alliance's Camera Serial
90  *		   Interface version 1 (MIPI CSI1) or Standard
91  *		   Mobile Imaging Architecture's Compact Camera Port 2
92  *		   (SMIA CCP2).
93  * @bus.mipi_csi2: embedded &struct v4l2_fwnode_bus_mipi_csi2.
94  *		   Used if the bus is MIPI Alliance's Camera Serial
95  *		   Interface version 2 (MIPI CSI2).
96  * @link_frequencies: array of supported link frequencies
97  * @nr_of_link_frequencies: number of elements in link_frequenccies array
98  */
99 struct v4l2_fwnode_endpoint {
100 	struct fwnode_endpoint base;
101 	/*
102 	 * Fields below this line will be zeroed by
103 	 * v4l2_fwnode_endpoint_parse()
104 	 */
105 	enum v4l2_mbus_type bus_type;
106 	union {
107 		struct v4l2_fwnode_bus_parallel parallel;
108 		struct v4l2_fwnode_bus_mipi_csi1 mipi_csi1;
109 		struct v4l2_fwnode_bus_mipi_csi2 mipi_csi2;
110 	} bus;
111 	u64 *link_frequencies;
112 	unsigned int nr_of_link_frequencies;
113 };
114 
115 /**
116  * struct v4l2_fwnode_link - a link between two endpoints
117  * @local_node: pointer to device_node of this endpoint
118  * @local_port: identifier of the port this endpoint belongs to
119  * @remote_node: pointer to device_node of the remote endpoint
120  * @remote_port: identifier of the port the remote endpoint belongs to
121  */
122 struct v4l2_fwnode_link {
123 	struct fwnode_handle *local_node;
124 	unsigned int local_port;
125 	struct fwnode_handle *remote_node;
126 	unsigned int remote_port;
127 };
128 
129 /**
130  * v4l2_fwnode_endpoint_parse() - parse all fwnode node properties
131  * @fwnode: pointer to the endpoint's fwnode handle
132  * @vep: pointer to the V4L2 fwnode data structure
133  *
134  * This function parses the V4L2 fwnode endpoint specific parameters from the
135  * firmware. The caller is responsible for assigning @vep.bus_type to a valid
136  * media bus type. The caller may also set the default configuration for the
137  * endpoint --- a configuration that shall be in line with the DT binding
138  * documentation. Should a device support multiple bus types, the caller may
139  * call this function once the correct type is found --- with a default
140  * configuration valid for that type.
141  *
142  * As a compatibility means guessing the bus type is also supported by setting
143  * @vep.bus_type to V4L2_MBUS_UNKNOWN. The caller may not provide a default
144  * configuration in this case as the defaults are specific to a given bus type.
145  * This functionality is deprecated and should not be used in new drivers and it
146  * is only supported for CSI-2 D-PHY, parallel and Bt.656 busses.
147  *
148  * The function does not change the V4L2 fwnode endpoint state if it fails.
149  *
150  * NOTE: This function does not parse properties the size of which is variable
151  * without a low fixed limit. Please use v4l2_fwnode_endpoint_alloc_parse() in
152  * new drivers instead.
153  *
154  * Return: %0 on success or a negative error code on failure:
155  *	   %-ENOMEM on memory allocation failure
156  *	   %-EINVAL on parsing failure
157  *	   %-ENXIO on mismatching bus types
158  */
159 int v4l2_fwnode_endpoint_parse(struct fwnode_handle *fwnode,
160 			       struct v4l2_fwnode_endpoint *vep);
161 
162 /**
163  * v4l2_fwnode_endpoint_free() - free the V4L2 fwnode acquired by
164  * v4l2_fwnode_endpoint_alloc_parse()
165  * @vep: the V4L2 fwnode the resources of which are to be released
166  *
167  * It is safe to call this function with NULL argument or on a V4L2 fwnode the
168  * parsing of which failed.
169  */
170 void v4l2_fwnode_endpoint_free(struct v4l2_fwnode_endpoint *vep);
171 
172 /**
173  * v4l2_fwnode_endpoint_alloc_parse() - parse all fwnode node properties
174  * @fwnode: pointer to the endpoint's fwnode handle
175  * @vep: pointer to the V4L2 fwnode data structure
176  *
177  * This function parses the V4L2 fwnode endpoint specific parameters from the
178  * firmware. The caller is responsible for assigning @vep.bus_type to a valid
179  * media bus type. The caller may also set the default configuration for the
180  * endpoint --- a configuration that shall be in line with the DT binding
181  * documentation. Should a device support multiple bus types, the caller may
182  * call this function once the correct type is found --- with a default
183  * configuration valid for that type.
184  *
185  * As a compatibility means guessing the bus type is also supported by setting
186  * @vep.bus_type to V4L2_MBUS_UNKNOWN. The caller may not provide a default
187  * configuration in this case as the defaults are specific to a given bus type.
188  * This functionality is deprecated and should not be used in new drivers and it
189  * is only supported for CSI-2 D-PHY, parallel and Bt.656 busses.
190  *
191  * The function does not change the V4L2 fwnode endpoint state if it fails.
192  *
193  * v4l2_fwnode_endpoint_alloc_parse() has two important differences to
194  * v4l2_fwnode_endpoint_parse():
195  *
196  * 1. It also parses variable size data.
197  *
198  * 2. The memory it has allocated to store the variable size data must be freed
199  *    using v4l2_fwnode_endpoint_free() when no longer needed.
200  *
201  * Return: %0 on success or a negative error code on failure:
202  *	   %-ENOMEM on memory allocation failure
203  *	   %-EINVAL on parsing failure
204  *	   %-ENXIO on mismatching bus types
205  */
206 int v4l2_fwnode_endpoint_alloc_parse(struct fwnode_handle *fwnode,
207 				     struct v4l2_fwnode_endpoint *vep);
208 
209 /**
210  * v4l2_fwnode_parse_link() - parse a link between two endpoints
211  * @fwnode: pointer to the endpoint's fwnode at the local end of the link
212  * @link: pointer to the V4L2 fwnode link data structure
213  *
214  * Fill the link structure with the local and remote nodes and port numbers.
215  * The local_node and remote_node fields are set to point to the local and
216  * remote port's parent nodes respectively (the port parent node being the
217  * parent node of the port node if that node isn't a 'ports' node, or the
218  * grand-parent node of the port node otherwise).
219  *
220  * A reference is taken to both the local and remote nodes, the caller must use
221  * v4l2_fwnode_put_link() to drop the references when done with the
222  * link.
223  *
224  * Return: 0 on success, or -ENOLINK if the remote endpoint fwnode can't be
225  * found.
226  */
227 int v4l2_fwnode_parse_link(struct fwnode_handle *fwnode,
228 			   struct v4l2_fwnode_link *link);
229 
230 /**
231  * v4l2_fwnode_put_link() - drop references to nodes in a link
232  * @link: pointer to the V4L2 fwnode link data structure
233  *
234  * Drop references to the local and remote nodes in the link. This function
235  * must be called on every link parsed with v4l2_fwnode_parse_link().
236  */
237 void v4l2_fwnode_put_link(struct v4l2_fwnode_link *link);
238 
239 /**
240  * typedef parse_endpoint_func - Driver's callback function to be called on
241  *	each V4L2 fwnode endpoint.
242  *
243  * @dev: pointer to &struct device
244  * @vep: pointer to &struct v4l2_fwnode_endpoint
245  * @asd: pointer to &struct v4l2_async_subdev
246  *
247  * Return:
248  * * %0 on success
249  * * %-ENOTCONN if the endpoint is to be skipped but this
250  *   should not be considered as an error
251  * * %-EINVAL if the endpoint configuration is invalid
252  */
253 typedef int (*parse_endpoint_func)(struct device *dev,
254 				  struct v4l2_fwnode_endpoint *vep,
255 				  struct v4l2_async_subdev *asd);
256 
257 /**
258  * v4l2_async_notifier_parse_fwnode_endpoints - Parse V4L2 fwnode endpoints in a
259  *						device node
260  * @dev: the device the endpoints of which are to be parsed
261  * @notifier: notifier for @dev
262  * @asd_struct_size: size of the driver's async sub-device struct, including
263  *		     sizeof(struct v4l2_async_subdev). The &struct
264  *		     v4l2_async_subdev shall be the first member of
265  *		     the driver's async sub-device struct, i.e. both
266  *		     begin at the same memory address.
267  * @parse_endpoint: Driver's callback function called on each V4L2 fwnode
268  *		    endpoint. Optional.
269  *
270  * Parse the fwnode endpoints of the @dev device and populate the async sub-
271  * devices list in the notifier. The @parse_endpoint callback function is
272  * called for each endpoint with the corresponding async sub-device pointer to
273  * let the caller initialize the driver-specific part of the async sub-device
274  * structure.
275  *
276  * The notifier memory shall be zeroed before this function is called on the
277  * notifier.
278  *
279  * This function may not be called on a registered notifier and may be called on
280  * a notifier only once.
281  *
282  * The &struct v4l2_fwnode_endpoint passed to the callback function
283  * @parse_endpoint is released once the function is finished. If there is a need
284  * to retain that configuration, the user needs to allocate memory for it.
285  *
286  * Any notifier populated using this function must be released with a call to
287  * v4l2_async_notifier_cleanup() after it has been unregistered and the async
288  * sub-devices are no longer in use, even if the function returned an error.
289  *
290  * Return: %0 on success, including when no async sub-devices are found
291  *	   %-ENOMEM if memory allocation failed
292  *	   %-EINVAL if graph or endpoint parsing failed
293  *	   Other error codes as returned by @parse_endpoint
294  */
295 int
296 v4l2_async_notifier_parse_fwnode_endpoints(struct device *dev,
297 					   struct v4l2_async_notifier *notifier,
298 					   size_t asd_struct_size,
299 					   parse_endpoint_func parse_endpoint);
300 
301 /**
302  * v4l2_async_notifier_parse_fwnode_endpoints_by_port - Parse V4L2 fwnode
303  *							endpoints of a port in a
304  *							device node
305  * @dev: the device the endpoints of which are to be parsed
306  * @notifier: notifier for @dev
307  * @asd_struct_size: size of the driver's async sub-device struct, including
308  *		     sizeof(struct v4l2_async_subdev). The &struct
309  *		     v4l2_async_subdev shall be the first member of
310  *		     the driver's async sub-device struct, i.e. both
311  *		     begin at the same memory address.
312  * @port: port number where endpoints are to be parsed
313  * @parse_endpoint: Driver's callback function called on each V4L2 fwnode
314  *		    endpoint. Optional.
315  *
316  * This function is just like v4l2_async_notifier_parse_fwnode_endpoints() with
317  * the exception that it only parses endpoints in a given port. This is useful
318  * on devices that have both sinks and sources: the async sub-devices connected
319  * to sources have already been configured by another driver (on capture
320  * devices). In this case the driver must know which ports to parse.
321  *
322  * Parse the fwnode endpoints of the @dev device on a given @port and populate
323  * the async sub-devices list of the notifier. The @parse_endpoint callback
324  * function is called for each endpoint with the corresponding async sub-device
325  * pointer to let the caller initialize the driver-specific part of the async
326  * sub-device structure.
327  *
328  * The notifier memory shall be zeroed before this function is called on the
329  * notifier the first time.
330  *
331  * This function may not be called on a registered notifier and may be called on
332  * a notifier only once per port.
333  *
334  * The &struct v4l2_fwnode_endpoint passed to the callback function
335  * @parse_endpoint is released once the function is finished. If there is a need
336  * to retain that configuration, the user needs to allocate memory for it.
337  *
338  * Any notifier populated using this function must be released with a call to
339  * v4l2_async_notifier_cleanup() after it has been unregistered and the async
340  * sub-devices are no longer in use, even if the function returned an error.
341  *
342  * Return: %0 on success, including when no async sub-devices are found
343  *	   %-ENOMEM if memory allocation failed
344  *	   %-EINVAL if graph or endpoint parsing failed
345  *	   Other error codes as returned by @parse_endpoint
346  */
347 int
348 v4l2_async_notifier_parse_fwnode_endpoints_by_port(struct device *dev,
349 						   struct v4l2_async_notifier *notifier,
350 						   size_t asd_struct_size,
351 						   unsigned int port,
352 						   parse_endpoint_func parse_endpoint);
353 
354 /**
355  * v4l2_fwnode_reference_parse_sensor_common - parse common references on
356  *					       sensors for async sub-devices
357  * @dev: the device node the properties of which are parsed for references
358  * @notifier: the async notifier where the async subdevs will be added
359  *
360  * Parse common sensor properties for remote devices related to the
361  * sensor and set up async sub-devices for them.
362  *
363  * Any notifier populated using this function must be released with a call to
364  * v4l2_async_notifier_release() after it has been unregistered and the async
365  * sub-devices are no longer in use, even in the case the function returned an
366  * error.
367  *
368  * Return: 0 on success
369  *	   -ENOMEM if memory allocation failed
370  *	   -EINVAL if property parsing failed
371  */
372 int v4l2_async_notifier_parse_fwnode_sensor_common(struct device *dev,
373 						   struct v4l2_async_notifier *notifier);
374 
375 /**
376  * v4l2_async_register_fwnode_subdev - registers a sub-device to the
377  *					asynchronous sub-device framework
378  *					and parses fwnode endpoints
379  *
380  * @sd: pointer to struct &v4l2_subdev
381  * @asd_struct_size: size of the driver's async sub-device struct, including
382  *		     sizeof(struct v4l2_async_subdev). The &struct
383  *		     v4l2_async_subdev shall be the first member of
384  *		     the driver's async sub-device struct, i.e. both
385  *		     begin at the same memory address.
386  * @ports: array of port id's to parse for fwnode endpoints. If NULL, will
387  *	   parse all ports owned by the sub-device.
388  * @num_ports: number of ports in @ports array. Ignored if @ports is NULL.
389  * @parse_endpoint: Driver's callback function called on each V4L2 fwnode
390  *		    endpoint. Optional.
391  *
392  * This function is just like v4l2_async_register_subdev() with the
393  * exception that calling it will also allocate a notifier for the
394  * sub-device, parse the sub-device's firmware node endpoints using
395  * v4l2_async_notifier_parse_fwnode_endpoints() or
396  * v4l2_async_notifier_parse_fwnode_endpoints_by_port(), and
397  * registers the sub-device notifier. The sub-device is similarly
398  * unregistered by calling v4l2_async_unregister_subdev().
399  *
400  * While registered, the subdev module is marked as in-use.
401  *
402  * An error is returned if the module is no longer loaded on any attempts
403  * to register it.
404  */
405 int
406 v4l2_async_register_fwnode_subdev(struct v4l2_subdev *sd,
407 				  size_t asd_struct_size,
408 				  unsigned int *ports,
409 				  unsigned int num_ports,
410 				  parse_endpoint_func parse_endpoint);
411 
412 #endif /* _V4L2_FWNODE_H */
413