linux/include/media/v4l2-fwnode.h
Mauro Carvalho Chehab d63a9ef241 media: v4l2-fwnode.h: better describe bus union at fwnode endpoint struct
Better document the bus union at struct v4l2_fwnode_endpoint.

Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-12-18 10:18:15 -05:00

362 lines
14 KiB
C

/*
* V4L2 fwnode binding parsing library
*
* Copyright (c) 2016 Intel Corporation.
* Author: Sakari Ailus <sakari.ailus@linux.intel.com>
*
* Copyright (C) 2012 - 2013 Samsung Electronics Co., Ltd.
* Author: Sylwester Nawrocki <s.nawrocki@samsung.com>
*
* Copyright (C) 2012 Renesas Electronics Corp.
* Author: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of version 2 of the GNU General Public License as
* published by the Free Software Foundation.
*/
#ifndef _V4L2_FWNODE_H
#define _V4L2_FWNODE_H
#include <linux/errno.h>
#include <linux/fwnode.h>
#include <linux/list.h>
#include <linux/types.h>
#include <media/v4l2-mediabus.h>
struct fwnode_handle;
struct v4l2_async_notifier;
struct v4l2_async_subdev;
#define V4L2_FWNODE_CSI2_MAX_DATA_LANES 4
/**
* struct v4l2_fwnode_bus_mipi_csi2 - MIPI CSI-2 bus data structure
* @flags: media bus (V4L2_MBUS_*) flags
* @data_lanes: an array of physical data lane indexes
* @clock_lane: physical lane index of the clock lane
* @num_data_lanes: number of data lanes
* @lane_polarities: polarity of the lanes. The order is the same of
* the physical lanes.
*/
struct v4l2_fwnode_bus_mipi_csi2 {
unsigned int flags;
unsigned char data_lanes[V4L2_FWNODE_CSI2_MAX_DATA_LANES];
unsigned char clock_lane;
unsigned short num_data_lanes;
bool lane_polarities[1 + V4L2_FWNODE_CSI2_MAX_DATA_LANES];
};
/**
* struct v4l2_fwnode_bus_parallel - parallel data bus data structure
* @flags: media bus (V4L2_MBUS_*) flags
* @bus_width: bus width in bits
* @data_shift: data shift in bits
*/
struct v4l2_fwnode_bus_parallel {
unsigned int flags;
unsigned char bus_width;
unsigned char data_shift;
};
/**
* struct v4l2_fwnode_bus_mipi_csi1 - CSI-1/CCP2 data bus structure
* @clock_inv: polarity of clock/strobe signal
* false - not inverted, true - inverted
* @strobe: false - data/clock, true - data/strobe
* @lane_polarity: the polarities of the clock (index 0) and data lanes
* index (1)
* @data_lane: the number of the data lane
* @clock_lane: the number of the clock lane
*/
struct v4l2_fwnode_bus_mipi_csi1 {
bool clock_inv;
bool strobe;
bool lane_polarity[2];
unsigned char data_lane;
unsigned char clock_lane;
};
/**
* struct v4l2_fwnode_endpoint - the endpoint data structure
* @base: fwnode endpoint of the v4l2_fwnode
* @bus_type: bus type
* @bus: union with bus configuration data structure
* @bus.parallel: embedded &struct v4l2_fwnode_bus_parallel.
* Used if the bus is parallel.
* @bus.mipi_csi1: embedded &struct v4l2_fwnode_bus_mipi_csi1.
* Used if the bus is MIPI Alliance's Camera Serial
* Interface version 1 (MIPI CSI1) or Standard
* Mobile Imaging Architecture's Compact Camera Port 2
* (SMIA CCP2).
* @bus.mipi_csi2: embedded &struct v4l2_fwnode_bus_mipi_csi2.
* Used if the bus is MIPI Alliance's Camera Serial
* Interface version 2 (MIPI CSI2).
* @link_frequencies: array of supported link frequencies
* @nr_of_link_frequencies: number of elements in link_frequenccies array
*/
struct v4l2_fwnode_endpoint {
struct fwnode_endpoint base;
/*
* Fields below this line will be zeroed by
* v4l2_fwnode_parse_endpoint()
*/
enum v4l2_mbus_type bus_type;
union {
struct v4l2_fwnode_bus_parallel parallel;
struct v4l2_fwnode_bus_mipi_csi1 mipi_csi1;
struct v4l2_fwnode_bus_mipi_csi2 mipi_csi2;
} bus;
u64 *link_frequencies;
unsigned int nr_of_link_frequencies;
};
/**
* struct v4l2_fwnode_link - a link between two endpoints
* @local_node: pointer to device_node of this endpoint
* @local_port: identifier of the port this endpoint belongs to
* @remote_node: pointer to device_node of the remote endpoint
* @remote_port: identifier of the port the remote endpoint belongs to
*/
struct v4l2_fwnode_link {
struct fwnode_handle *local_node;
unsigned int local_port;
struct fwnode_handle *remote_node;
unsigned int remote_port;
};
/**
* v4l2_fwnode_endpoint_parse() - parse all fwnode node properties
* @fwnode: pointer to the endpoint's fwnode handle
* @vep: pointer to the V4L2 fwnode data structure
*
* All properties are optional. If none are found, we don't set any flags. This
* means the port has a static configuration and no properties have to be
* specified explicitly. If any properties that identify the bus as parallel
* are found and slave-mode isn't set, we set V4L2_MBUS_MASTER. Similarly, if
* we recognise the bus as serial CSI-2 and clock-noncontinuous isn't set, we
* set the V4L2_MBUS_CSI2_CONTINUOUS_CLOCK flag. The caller should hold a
* reference to @fwnode.
*
* NOTE: This function does not parse properties the size of which is variable
* without a low fixed limit. Please use v4l2_fwnode_endpoint_alloc_parse() in
* new drivers instead.
*
* Return: 0 on success or a negative error code on failure.
*/
int v4l2_fwnode_endpoint_parse(struct fwnode_handle *fwnode,
struct v4l2_fwnode_endpoint *vep);
/**
* v4l2_fwnode_endpoint_free() - free the V4L2 fwnode acquired by
* v4l2_fwnode_endpoint_alloc_parse()
* @vep: the V4L2 fwnode the resources of which are to be released
*
* It is safe to call this function with NULL argument or on a V4L2 fwnode the
* parsing of which failed.
*/
void v4l2_fwnode_endpoint_free(struct v4l2_fwnode_endpoint *vep);
/**
* v4l2_fwnode_endpoint_alloc_parse() - parse all fwnode node properties
* @fwnode: pointer to the endpoint's fwnode handle
*
* All properties are optional. If none are found, we don't set any flags. This
* means the port has a static configuration and no properties have to be
* specified explicitly. If any properties that identify the bus as parallel
* are found and slave-mode isn't set, we set V4L2_MBUS_MASTER. Similarly, if
* we recognise the bus as serial CSI-2 and clock-noncontinuous isn't set, we
* set the V4L2_MBUS_CSI2_CONTINUOUS_CLOCK flag. The caller should hold a
* reference to @fwnode.
*
* v4l2_fwnode_endpoint_alloc_parse() has two important differences to
* v4l2_fwnode_endpoint_parse():
*
* 1. It also parses variable size data.
*
* 2. The memory it has allocated to store the variable size data must be freed
* using v4l2_fwnode_endpoint_free() when no longer needed.
*
* Return: Pointer to v4l2_fwnode_endpoint if successful, on an error pointer
* on error.
*/
struct v4l2_fwnode_endpoint *v4l2_fwnode_endpoint_alloc_parse(
struct fwnode_handle *fwnode);
/**
* v4l2_fwnode_parse_link() - parse a link between two endpoints
* @fwnode: pointer to the endpoint's fwnode at the local end of the link
* @link: pointer to the V4L2 fwnode link data structure
*
* Fill the link structure with the local and remote nodes and port numbers.
* The local_node and remote_node fields are set to point to the local and
* remote port's parent nodes respectively (the port parent node being the
* parent node of the port node if that node isn't a 'ports' node, or the
* grand-parent node of the port node otherwise).
*
* A reference is taken to both the local and remote nodes, the caller must use
* v4l2_fwnode_put_link() to drop the references when done with the
* link.
*
* Return: 0 on success, or -ENOLINK if the remote endpoint fwnode can't be
* found.
*/
int v4l2_fwnode_parse_link(struct fwnode_handle *fwnode,
struct v4l2_fwnode_link *link);
/**
* v4l2_fwnode_put_link() - drop references to nodes in a link
* @link: pointer to the V4L2 fwnode link data structure
*
* Drop references to the local and remote nodes in the link. This function
* must be called on every link parsed with v4l2_fwnode_parse_link().
*/
void v4l2_fwnode_put_link(struct v4l2_fwnode_link *link);
/**
* typedef parse_endpoint_func - Driver's callback function to be called on
* each V4L2 fwnode endpoint.
*
* @dev: pointer to &struct device
* @vep: pointer to &struct v4l2_fwnode_endpoint
* @asd: pointer to &struct v4l2_async_subdev
*
* Return:
* * %0 on success
* * %-ENOTCONN if the endpoint is to be skipped but this
* should not be considered as an error
* * %-EINVAL if the endpoint configuration is invalid
*/
typedef int (*parse_endpoint_func)(struct device *dev,
struct v4l2_fwnode_endpoint *vep,
struct v4l2_async_subdev *asd);
/**
* v4l2_async_notifier_parse_fwnode_endpoints - Parse V4L2 fwnode endpoints in a
* device node
* @dev: the device the endpoints of which are to be parsed
* @notifier: notifier for @dev
* @asd_struct_size: size of the driver's async sub-device struct, including
* sizeof(struct v4l2_async_subdev). The &struct
* v4l2_async_subdev shall be the first member of
* the driver's async sub-device struct, i.e. both
* begin at the same memory address.
* @parse_endpoint: Driver's callback function called on each V4L2 fwnode
* endpoint. Optional.
*
* Parse the fwnode endpoints of the @dev device and populate the async sub-
* devices array of the notifier. The @parse_endpoint callback function is
* called for each endpoint with the corresponding async sub-device pointer to
* let the caller initialize the driver-specific part of the async sub-device
* structure.
*
* The notifier memory shall be zeroed before this function is called on the
* notifier.
*
* This function may not be called on a registered notifier and may be called on
* a notifier only once.
*
* Do not change the notifier's subdevs array, take references to the subdevs
* array itself or change the notifier's num_subdevs field. This is because this
* function allocates and reallocates the subdevs array based on parsing
* endpoints.
*
* The &struct v4l2_fwnode_endpoint passed to the callback function
* @parse_endpoint is released once the function is finished. If there is a need
* to retain that configuration, the user needs to allocate memory for it.
*
* Any notifier populated using this function must be released with a call to
* v4l2_async_notifier_cleanup() after it has been unregistered and the async
* sub-devices are no longer in use, even if the function returned an error.
*
* Return: %0 on success, including when no async sub-devices are found
* %-ENOMEM if memory allocation failed
* %-EINVAL if graph or endpoint parsing failed
* Other error codes as returned by @parse_endpoint
*/
int v4l2_async_notifier_parse_fwnode_endpoints(
struct device *dev, struct v4l2_async_notifier *notifier,
size_t asd_struct_size,
parse_endpoint_func parse_endpoint);
/**
* v4l2_async_notifier_parse_fwnode_endpoints_by_port - Parse V4L2 fwnode
* endpoints of a port in a
* device node
* @dev: the device the endpoints of which are to be parsed
* @notifier: notifier for @dev
* @asd_struct_size: size of the driver's async sub-device struct, including
* sizeof(struct v4l2_async_subdev). The &struct
* v4l2_async_subdev shall be the first member of
* the driver's async sub-device struct, i.e. both
* begin at the same memory address.
* @port: port number where endpoints are to be parsed
* @parse_endpoint: Driver's callback function called on each V4L2 fwnode
* endpoint. Optional.
*
* This function is just like v4l2_async_notifier_parse_fwnode_endpoints() with
* the exception that it only parses endpoints in a given port. This is useful
* on devices that have both sinks and sources: the async sub-devices connected
* to sources have already been configured by another driver (on capture
* devices). In this case the driver must know which ports to parse.
*
* Parse the fwnode endpoints of the @dev device on a given @port and populate
* the async sub-devices array of the notifier. The @parse_endpoint callback
* function is called for each endpoint with the corresponding async sub-device
* pointer to let the caller initialize the driver-specific part of the async
* sub-device structure.
*
* The notifier memory shall be zeroed before this function is called on the
* notifier the first time.
*
* This function may not be called on a registered notifier and may be called on
* a notifier only once per port.
*
* Do not change the notifier's subdevs array, take references to the subdevs
* array itself or change the notifier's num_subdevs field. This is because this
* function allocates and reallocates the subdevs array based on parsing
* endpoints.
*
* The &struct v4l2_fwnode_endpoint passed to the callback function
* @parse_endpoint is released once the function is finished. If there is a need
* to retain that configuration, the user needs to allocate memory for it.
*
* Any notifier populated using this function must be released with a call to
* v4l2_async_notifier_cleanup() after it has been unregistered and the async
* sub-devices are no longer in use, even if the function returned an error.
*
* Return: %0 on success, including when no async sub-devices are found
* %-ENOMEM if memory allocation failed
* %-EINVAL if graph or endpoint parsing failed
* Other error codes as returned by @parse_endpoint
*/
int v4l2_async_notifier_parse_fwnode_endpoints_by_port(
struct device *dev, struct v4l2_async_notifier *notifier,
size_t asd_struct_size, unsigned int port,
parse_endpoint_func parse_endpoint);
/**
* v4l2_fwnode_reference_parse_sensor_common - parse common references on
* sensors for async sub-devices
* @dev: the device node the properties of which are parsed for references
* @notifier: the async notifier where the async subdevs will be added
*
* Parse common sensor properties for remote devices related to the
* sensor and set up async sub-devices for them.
*
* Any notifier populated using this function must be released with a call to
* v4l2_async_notifier_release() after it has been unregistered and the async
* sub-devices are no longer in use, even in the case the function returned an
* error.
*
* Return: 0 on success
* -ENOMEM if memory allocation failed
* -EINVAL if property parsing failed
*/
int v4l2_async_notifier_parse_fwnode_sensor_common(
struct device *dev, struct v4l2_async_notifier *notifier);
#endif /* _V4L2_FWNODE_H */