1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3 * Greybus Camera protocol driver.
4 *
5 * Copyright 2015 Google Inc.
6 */
7 #ifndef __GB_CAMERA_H
8 #define __GB_CAMERA_H
9
10 #include <linux/v4l2-mediabus.h>
11
12 /* Input flags need to be set from the caller */
13 #define GB_CAMERA_IN_FLAG_TEST (1 << 0)
14 /* Output flags returned */
15 #define GB_CAMERA_OUT_FLAG_ADJUSTED (1 << 0)
16
17 /**
18 * struct gb_camera_stream - Represents greybus camera stream.
19 * @width: Stream width in pixels.
20 * @height: Stream height in pixels.
21 * @pixel_code: Media bus pixel code.
22 * @vc: MIPI CSI virtual channel.
23 * @dt: MIPI CSI data types. Most formats use a single data type, in which case
24 * the second element will be ignored.
25 * @max_size: Maximum size of a frame in bytes. The camera module guarantees
26 * that all data between the Frame Start and Frame End packet for
27 * the associated virtual channel and data type(s) will not exceed
28 * this size.
29 */
30 struct gb_camera_stream {
31 unsigned int width;
32 unsigned int height;
33 enum v4l2_mbus_pixelcode pixel_code;
34 unsigned int vc;
35 unsigned int dt[2];
36 unsigned int max_size;
37 };
38
39 /**
40 * struct gb_camera_csi_params - CSI configuration parameters
41 * @num_lanes: number of CSI data lanes
42 * @clk_freq: CSI clock frequency in Hz
43 */
44 struct gb_camera_csi_params {
45 unsigned int num_lanes;
46 unsigned int clk_freq;
47 };
48
49 /**
50 * struct gb_camera_ops - Greybus camera operations, used by the Greybus camera
51 * driver to expose operations to the host camera driver.
52 * @capabilities: Retrieve camera capabilities and store them in the buffer
53 * 'buf' capabilities. The buffer maximum size is specified by
54 * the caller in the 'size' parameter, and the effective
55 * capabilities size is returned from the function. If the buffer
56 * size is too small to hold the capabilities an error is
57 * returned and the buffer is left untouched.
58 *
59 * @configure_streams: Negotiate configuration and prepare the module for video
60 * capture. The caller specifies the number of streams it
61 * requests in the 'nstreams' argument and the associated
62 * streams configurations in the 'streams' argument. The
63 * GB_CAMERA_IN_FLAG_TEST 'flag' can be set to test a
64 * configuration without applying it, otherwise the
65 * configuration is applied by the module. The module can
66 * decide to modify the requested configuration, including
67 * using a different number of streams. In that case the
68 * modified configuration won't be applied, the
69 * GB_CAMERA_OUT_FLAG_ADJUSTED 'flag' will be set upon
70 * return, and the modified configuration and number of
71 * streams stored in 'streams' and 'array'. The module
72 * returns its CSI-2 bus parameters in the 'csi_params'
73 * structure in all cases.
74 *
75 * @capture: Submit a capture request. The supplied 'request_id' must be unique
76 * and higher than the IDs of all the previously submitted requests.
77 * The 'streams' argument specifies which streams are affected by the
78 * request in the form of a bitmask, with bits corresponding to the
79 * configured streams indexes. If the request contains settings, the
80 * 'settings' argument points to the settings buffer and its size is
81 * specified by the 'settings_size' argument. Otherwise the 'settings'
82 * argument should be set to NULL and 'settings_size' to 0.
83 *
84 * @flush: Flush the capture requests queue. Return the ID of the last request
85 * that will processed by the device before it stops transmitting video
86 * frames. All queued capture requests with IDs higher than the returned
87 * ID will be dropped without being processed.
88 */
89 struct gb_camera_ops {
90 ssize_t (*capabilities)(void *priv, char *buf, size_t len);
91 int (*configure_streams)(void *priv, unsigned int *nstreams,
92 unsigned int *flags, struct gb_camera_stream *streams,
93 struct gb_camera_csi_params *csi_params);
94 int (*capture)(void *priv, u32 request_id,
95 unsigned int streams, unsigned int num_frames,
96 size_t settings_size, const void *settings);
97 int (*flush)(void *priv, u32 *request_id);
98 };
99
100 /**
101 * struct gb_camera_module - Represents greybus camera module.
102 * @priv: Module private data, passed to all camera operations.
103 * @ops: Greybus camera operation callbacks.
104 * @interface_id: Interface id of the module.
105 * @refcount: Reference counting object.
106 * @release: Module release function.
107 * @list: List entry in the camera modules list.
108 */
109 struct gb_camera_module {
110 void *priv;
111 const struct gb_camera_ops *ops;
112
113 unsigned int interface_id;
114 struct kref refcount;
115 void (*release)(struct kref *kref);
116 struct list_head list; /* Global list */
117 };
118
119 #define gb_camera_call(f, op, args...) \
120 (!(f) ? -ENODEV : (((f)->ops->op) ? \
121 (f)->ops->op((f)->priv, ##args) : -ENOIOCTLCMD))
122
123 int gb_camera_register(struct gb_camera_module *module);
124 int gb_camera_unregister(struct gb_camera_module *module);
125
126 #endif /* __GB_CAMERA_H */