gb-camera.h

  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 */