drivers/staging/greybus/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  */
  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 */