1 /* 2 * Greybus Camera protocol driver. 3 * 4 * Copyright 2015 Google Inc. 5 * 6 * Released under the GPLv2 only. 7 */ 8 #ifndef __GB_CAMERA_H 9 #define __GB_CAMERA_H 10 11 #include <linux/v4l2-mediabus.h> 12 13 /* Input flags need to be set from the caller */ 14 #define GB_CAMERA_IN_FLAG_TEST (1 << 0) 15 /* Output flags returned */ 16 #define GB_CAMERA_OUT_FLAG_ADJUSTED (1 << 0) 17 18 /** 19 * struct gb_camera_stream - Represents greybus camera stream. 20 * @width: Stream width in pixels. 21 * @height: Stream height in pixels. 22 * @pixel_code: Media bus pixel code. 23 * @vc: MIPI CSI virtual channel. 24 * @dt: MIPI CSI data types. Most formats use a single data type, in which case 25 * the second element will be ignored. 26 * @max_size: Maximum size of a frame in bytes. The camera module guarantees 27 * that all data between the Frame Start and Frame End packet for 28 * the associated virtual channel and data type(s) will not exceed 29 * this size. 30 */ 31 struct gb_camera_stream { 32 unsigned int width; 33 unsigned int height; 34 enum v4l2_mbus_pixelcode pixel_code; 35 unsigned int vc; 36 unsigned int dt[2]; 37 unsigned int max_size; 38 }; 39 40 /** 41 * struct gb_camera_csi_params - CSI configuration parameters 42 * @num_lanes: number of CSI data lanes 43 * @clk_freq: CSI clock frequency in Hz 44 */ 45 struct gb_camera_csi_params { 46 unsigned int num_lanes; 47 unsigned int clk_freq; 48 }; 49 50 /** 51 * struct gb_camera_ops - Greybus camera operations, used by the Greybus camera 52 * driver to expose operations to the host camera driver. 53 * @capabilities: Retrieve camera capabilities and store them in the buffer 54 * 'buf' capabilities. The buffer maximum size is specified by 55 * the caller in the 'size' parameter, and the effective 56 * capabilities size is returned from the function. If the buffer 57 * size is too small to hold the capabilities an error is 58 * returned and the buffer is left untouched. 59 * 60 * @configure_streams: Negotiate configuration and prepare the module for video 61 * capture. The caller specifies the number of streams it 62 * requests in the 'nstreams' argument and the associated 63 * streams configurations in the 'streams' argument. The 64 * GB_CAMERA_IN_FLAG_TEST 'flag' can be set to test a 65 * configuration without applying it, otherwise the 66 * configuration is applied by the module. The module can 67 * decide to modify the requested configuration, including 68 * using a different number of streams. In that case the 69 * modified configuration won't be applied, the 70 * GB_CAMERA_OUT_FLAG_ADJUSTED 'flag' will be set upon 71 * return, and the modified configuration and number of 72 * streams stored in 'streams' and 'array'. The module 73 * returns its CSI-2 bus parameters in the 'csi_params' 74 * structure in all cases. 75 * 76 * @capture: Submit a capture request. The supplied 'request_id' must be unique 77 * and higher than the IDs of all the previously submitted requests. 78 * The 'streams' argument specifies which streams are affected by the 79 * request in the form of a bitmask, with bits corresponding to the 80 * configured streams indexes. If the request contains settings, the 81 * 'settings' argument points to the settings buffer and its size is 82 * specified by the 'settings_size' argument. Otherwise the 'settings' 83 * argument should be set to NULL and 'settings_size' to 0. 84 * 85 * @flush: Flush the capture requests queue. Return the ID of the last request 86 * that will processed by the device before it stops transmitting video 87 * frames. All queued capture requests with IDs higher than the returned 88 * ID will be dropped without being processed. 89 */ 90 struct gb_camera_ops { 91 ssize_t (*capabilities)(void *priv, char *buf, size_t len); 92 int (*configure_streams)(void *priv, unsigned int *nstreams, 93 unsigned int *flags, struct gb_camera_stream *streams, 94 struct gb_camera_csi_params *csi_params); 95 int (*capture)(void *priv, u32 request_id, 96 unsigned int streams, unsigned int num_frames, 97 size_t settings_size, const void *settings); 98 int (*flush)(void *priv, u32 *request_id); 99 }; 100 101 /** 102 * struct gb_camera_module - Represents greybus camera module. 103 * @priv: Module private data, passed to all camera operations. 104 * @ops: Greybus camera operation callbacks. 105 * @interface_id: Interface id of the module. 106 * @refcount: Reference counting object. 107 * @release: Module release function. 108 * @list: List entry in the camera modules list. 109 */ 110 struct gb_camera_module { 111 void *priv; 112 const struct gb_camera_ops *ops; 113 114 unsigned int interface_id; 115 struct kref refcount; 116 void (*release)(struct kref *kref); 117 struct list_head list; /* Global list */ 118 }; 119 120 #define gb_camera_call(f, op, args...) \ 121 (!(f) ? -ENODEV : (((f)->ops->op) ? \ 122 (f)->ops->op((f)->priv, ##args) : -ENOIOCTLCMD)) 123 124 int gb_camera_register(struct gb_camera_module *module); 125 int gb_camera_unregister(struct gb_camera_module *module); 126 127 #endif /* __GB_CAMERA_H */ 128