drivers/staging/greybus/gb-camera.h

   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 */