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// SPDX-License-Identifier: GPL-2.0
/*
* Greybus Camera protocol driver.
*
* Copyright 2015 Google Inc.
*/
#ifndef __GB_CAMERA_H
#define __GB_CAMERA_H
#include <linux/v4l2-mediabus.h>
/* Input flags need to be set from the caller */
#define GB_CAMERA_IN_FLAG_TEST (1 << 0)
/* Output flags returned */
#define GB_CAMERA_OUT_FLAG_ADJUSTED (1 << 0)
/**
* struct gb_camera_stream - Represents greybus camera stream.
* @width: Stream width in pixels.
* @height: Stream height in pixels.
* @pixel_code: Media bus pixel code.
* @vc: MIPI CSI virtual channel.
* @dt: MIPI CSI data types. Most formats use a single data type, in which case
* the second element will be ignored.
* @max_size: Maximum size of a frame in bytes. The camera module guarantees
* that all data between the Frame Start and Frame End packet for
* the associated virtual channel and data type(s) will not exceed
* this size.
*/
struct gb_camera_stream {
unsigned int width;
unsigned int height;
enum v4l2_mbus_pixelcode pixel_code;
unsigned int vc;
unsigned int dt[2];
unsigned int max_size;
};
/**
* struct gb_camera_csi_params - CSI configuration parameters
* @num_lanes: number of CSI data lanes
* @clk_freq: CSI clock frequency in Hz
*/
struct gb_camera_csi_params {
unsigned int num_lanes;
unsigned int clk_freq;
};
/**
* struct gb_camera_ops - Greybus camera operations, used by the Greybus camera
* driver to expose operations to the host camera driver.
* @capabilities: Retrieve camera capabilities and store them in the buffer
* 'buf' capabilities. The buffer maximum size is specified by
* the caller in the 'size' parameter, and the effective
* capabilities size is returned from the function. If the buffer
* size is too small to hold the capabilities an error is
* returned and the buffer is left untouched.
*
* @configure_streams: Negotiate configuration and prepare the module for video
* capture. The caller specifies the number of streams it
* requests in the 'nstreams' argument and the associated
* streams configurations in the 'streams' argument. The
* GB_CAMERA_IN_FLAG_TEST 'flag' can be set to test a
* configuration without applying it, otherwise the
* configuration is applied by the module. The module can
* decide to modify the requested configuration, including
* using a different number of streams. In that case the
* modified configuration won't be applied, the
* GB_CAMERA_OUT_FLAG_ADJUSTED 'flag' will be set upon
* return, and the modified configuration and number of
* streams stored in 'streams' and 'array'. The module
* returns its CSI-2 bus parameters in the 'csi_params'
* structure in all cases.
*
* @capture: Submit a capture request. The supplied 'request_id' must be unique
* and higher than the IDs of all the previously submitted requests.
* The 'streams' argument specifies which streams are affected by the
* request in the form of a bitmask, with bits corresponding to the
* configured streams indexes. If the request contains settings, the
* 'settings' argument points to the settings buffer and its size is
* specified by the 'settings_size' argument. Otherwise the 'settings'
* argument should be set to NULL and 'settings_size' to 0.
*
* @flush: Flush the capture requests queue. Return the ID of the last request
* that will processed by the device before it stops transmitting video
* frames. All queued capture requests with IDs higher than the returned
* ID will be dropped without being processed.
*/
struct gb_camera_ops {
ssize_t (*capabilities)(void *priv, char *buf, size_t len);
int (*configure_streams)(void *priv, unsigned int *nstreams,
unsigned int *flags, struct gb_camera_stream *streams,
struct gb_camera_csi_params *csi_params);
int (*capture)(void *priv, u32 request_id,
unsigned int streams, unsigned int num_frames,
size_t settings_size, const void *settings);
int (*flush)(void *priv, u32 *request_id);
};
/**
* struct gb_camera_module - Represents greybus camera module.
* @priv: Module private data, passed to all camera operations.
* @ops: Greybus camera operation callbacks.
* @interface_id: Interface id of the module.
* @refcount: Reference counting object.
* @release: Module release function.
* @list: List entry in the camera modules list.
*/
struct gb_camera_module {
void *priv;
const struct gb_camera_ops *ops;
unsigned int interface_id;
struct kref refcount;
void (*release)(struct kref *kref);
struct list_head list; /* Global list */
};
#define gb_camera_call(f, op, args...) \
(!(f) ? -ENODEV : (((f)->ops->op) ? \
(f)->ops->op((f)->priv, ##args) : -ENOIOCTLCMD))
int gb_camera_register(struct gb_camera_module *module);
int gb_camera_unregister(struct gb_camera_module *module);
#endif /* __GB_CAMERA_H */