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 */
30struct 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 */
44struct 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 */
89struct 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 */
109struct 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
123int gb_camera_register(struct gb_camera_module *module);
124int gb_camera_unregister(struct gb_camera_module *module);
125
126#endif /* __GB_CAMERA_H */
127