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[media] Add a V4L2 OF parser

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Add a V4L2 OF parser, implementing bindings documented in
Documentation/devicetree/bindings/media/video-interfaces.txt.
[s.nawrocki@samsung.com: various corrections and improvements
since the initial version]

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
This commit is contained in:
Guennadi Liakhovetski 2012-09-26 05:24:03 -03:00 committed by Mauro Carvalho Chehab
parent 53c5b6c95f
commit 99fd133f90
3 changed files with 381 additions and 0 deletions
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3
drivers/media/v4l2-core/Makefile
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@ -9,6 +9,9 @@ videodev-objs := v4l2-dev.o v4l2-ioctl.o v4l2-device.o v4l2-fh.o \
ifeq ($(CONFIG_COMPAT),y)
videodev-objs += v4l2-compat-ioctl32.o
endif
ifeq ($(CONFIG_OF),y)
videodev-objs += v4l2-of.o
endif
obj-$(CONFIG_VIDEO_DEV) += videodev.o
obj-$(CONFIG_VIDEO_V4L2_INT_DEVICE) += v4l2-int-device.o

267
drivers/media/v4l2-core/v4l2-of.c Normal file
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@ -0,0 +1,267 @@
/*
* V4L2 OF binding parsing library
*
* Copyright (C) 2012 - 2013 Samsung Electronics Co., Ltd.
* 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.
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/string.h>
#include <linux/types.h>
#include <media/v4l2-of.h>
static void v4l2_of_parse_csi_bus(const struct device_node *node,
struct v4l2_of_endpoint *endpoint)
{
struct v4l2_of_bus_mipi_csi2 *bus = &endpoint->bus.mipi_csi2;
u32 data_lanes[ARRAY_SIZE(bus->data_lanes)];
struct property *prop;
bool have_clk_lane = false;
unsigned int flags = 0;
u32 v;
prop = of_find_property(node, "data-lanes", NULL);
if (prop) {
const __be32 *lane = NULL;
int i;
for (i = 0; i < ARRAY_SIZE(data_lanes); i++) {
lane = of_prop_next_u32(prop, lane, &data_lanes[i]);
if (!lane)
break;
}
bus->num_data_lanes = i;
while (i--)
bus->data_lanes[i] = data_lanes[i];
}
if (!of_property_read_u32(node, "clock-lanes", &v)) {
bus->clock_lane = v;
have_clk_lane = true;
}
if (of_get_property(node, "clock-noncontinuous", &v))
flags |= V4L2_MBUS_CSI2_NONCONTINUOUS_CLOCK;
else if (have_clk_lane || bus->num_data_lanes > 0)
flags |= V4L2_MBUS_CSI2_CONTINUOUS_CLOCK;
bus->flags = flags;
endpoint->bus_type = V4L2_MBUS_CSI2;
}
static void v4l2_of_parse_parallel_bus(const struct device_node *node,
struct v4l2_of_endpoint *endpoint)
{
struct v4l2_of_bus_parallel *bus = &endpoint->bus.parallel;
unsigned int flags = 0;
u32 v;
if (!of_property_read_u32(node, "hsync-active", &v))
flags |= v ? V4L2_MBUS_HSYNC_ACTIVE_HIGH :
V4L2_MBUS_HSYNC_ACTIVE_LOW;
if (!of_property_read_u32(node, "vsync-active", &v))
flags |= v ? V4L2_MBUS_VSYNC_ACTIVE_HIGH :
V4L2_MBUS_VSYNC_ACTIVE_LOW;
if (!of_property_read_u32(node, "pclk-sample", &v))
flags |= v ? V4L2_MBUS_PCLK_SAMPLE_RISING :
V4L2_MBUS_PCLK_SAMPLE_FALLING;
if (!of_property_read_u32(node, "field-even-active", &v))
flags |= v ? V4L2_MBUS_FIELD_EVEN_HIGH :
V4L2_MBUS_FIELD_EVEN_LOW;
if (flags)
endpoint->bus_type = V4L2_MBUS_PARALLEL;
else
endpoint->bus_type = V4L2_MBUS_BT656;
if (!of_property_read_u32(node, "data-active", &v))
flags |= v ? V4L2_MBUS_DATA_ACTIVE_HIGH :
V4L2_MBUS_DATA_ACTIVE_LOW;
if (of_get_property(node, "slave-mode", &v))
flags |= V4L2_MBUS_SLAVE;
else
flags |= V4L2_MBUS_MASTER;
if (!of_property_read_u32(node, "bus-width", &v))
bus->bus_width = v;
if (!of_property_read_u32(node, "data-shift", &v))
bus->data_shift = v;
bus->flags = flags;
}
EXPORT_SYMBOL(v4l2_of_parse_parallel_bus);
/**
* v4l2_of_parse_endpoint() - parse all endpoint node properties
* @node: pointer to endpoint device_node
* @endpoint: pointer to the V4L2 OF endpoint 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 @node.
*/
void v4l2_of_parse_endpoint(const struct device_node *node,
struct v4l2_of_endpoint *endpoint)
{
struct device_node *port_node = of_get_parent(node);
memset(endpoint, 0, offsetof(struct v4l2_of_endpoint, head));
endpoint->local_node = node;
/*
* It doesn't matter whether the two calls below succeed.
* If they don't then the default value 0 is used.
*/
of_property_read_u32(port_node, "reg", &endpoint->port);
of_property_read_u32(node, "reg", &endpoint->id);
v4l2_of_parse_csi_bus(node, endpoint);
/*
* Parse the parallel video bus properties only if none
* of the MIPI CSI-2 specific properties were found.
*/
if (endpoint->bus.mipi_csi2.flags == 0)
v4l2_of_parse_parallel_bus(node, endpoint);
of_node_put(port_node);
}
EXPORT_SYMBOL(v4l2_of_parse_endpoint);
/**
* v4l2_of_get_next_endpoint() - get next endpoint node
* @parent: pointer to the parent device node
* @prev: previous endpoint node, or NULL to get first
*
* Return: An 'endpoint' node pointer with refcount incremented. Refcount
* of the passed @prev node is not decremented, the caller have to use
* of_node_put() on it when done.
*/
struct device_node *v4l2_of_get_next_endpoint(const struct device_node *parent,
struct device_node *prev)
{
struct device_node *endpoint;
struct device_node *port = NULL;
if (!parent)
return NULL;
if (!prev) {
struct device_node *node;
/*
* It's the first call, we have to find a port subnode
* within this node or within an optional 'ports' node.
*/
node = of_get_child_by_name(parent, "ports");
if (node)
parent = node;
for_each_child_of_node(parent, node) {
if (!of_node_cmp(node->name, "port")) {
port = node;
break;
}
}
if (port) {
/* Found a port, get an endpoint. */
endpoint = of_get_next_child(port, NULL);
of_node_put(port);
} else {
endpoint = NULL;
}
if (!endpoint)
pr_err("%s(): no endpoint nodes specified for %s\n",
__func__, parent->full_name);
} else {
port = of_get_parent(prev);
if (!port)
/* Hm, has someone given us the root node ?... */
return NULL;
/* Avoid dropping prev node refcount to 0. */
of_node_get(prev);
endpoint = of_get_next_child(port, prev);
if (endpoint) {
of_node_put(port);
return endpoint;
}
/* No more endpoints under this port, try the next one. */
do {
port = of_get_next_child(parent, port);
if (!port)
return NULL;
} while (of_node_cmp(port->name, "port"));
/* Pick up the first endpoint in this port. */
endpoint = of_get_next_child(port, NULL);
of_node_put(port);
}
return endpoint;
}
EXPORT_SYMBOL(v4l2_of_get_next_endpoint);
/**
* v4l2_of_get_remote_port_parent() - get remote port's parent node
* @node: pointer to a local endpoint device_node
*
* Return: Remote device node associated with remote endpoint node linked
* to @node. Use of_node_put() on it when done.
*/
struct device_node *v4l2_of_get_remote_port_parent(
const struct device_node *node)
{
struct device_node *np;
unsigned int depth;
/* Get remote endpoint node. */
np = of_parse_phandle(node, "remote-endpoint", 0);
/* Walk 3 levels up only if there is 'ports' node. */
for (depth = 3; depth && np; depth--) {
np = of_get_next_parent(np);
if (depth == 2 && of_node_cmp(np->name, "ports"))
break;
}
return np;
}
EXPORT_SYMBOL(v4l2_of_get_remote_port_parent);
/**
* v4l2_of_get_remote_port() - get remote port node
* @node: pointer to a local endpoint device_node
*
* Return: Remote port node associated with remote endpoint node linked
* to @node. Use of_node_put() on it when done.
*/
struct device_node *v4l2_of_get_remote_port(const struct device_node *node)
{
struct device_node *np;
/* Get remote endpoint node. */
np = of_parse_phandle(node, "remote-endpoint", 0);
if (!np)
return NULL;
return of_get_parent(np);
}
EXPORT_SYMBOL(v4l2_of_get_remote_port);

111
include/media/v4l2-of.h Normal file
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@ -0,0 +1,111 @@
/*
* V4L2 OF binding parsing library
*
* Copyright (C) 2012 Renesas Electronics Corp.
* Author: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
*
* Copyright (C) 2012 - 2013 Samsung Electronics Co., Ltd.
* Sylwester Nawrocki <s.nawrocki@samsung.com>
*
* 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_OF_H
#define _V4L2_OF_H
#include <linux/list.h>
#include <linux/types.h>
#include <linux/errno.h>
#include <media/v4l2-mediabus.h>
struct device_node;
/**
* struct v4l2_of_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
*/
struct v4l2_of_bus_mipi_csi2 {
unsigned int flags;
unsigned char data_lanes[4];
unsigned char clock_lane;
unsigned short num_data_lanes;
};
/**
* struct v4l2_of_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_of_bus_parallel {
unsigned int flags;
unsigned char bus_width;
unsigned char data_shift;
};
/**
* struct v4l2_of_endpoint - the endpoint data structure
* @port: identifier (value of reg property) of a port this endpoint belongs to
* @id: identifier (value of reg property) of this endpoint
* @local_node: pointer to device_node of this endpoint
* @remote: phandle to remote endpoint node
* @bus_type: bus type
* @bus: bus configuration data structure
* @head: list head for this structure
*/
struct v4l2_of_endpoint {
unsigned int port;
unsigned int id;
const struct device_node *local_node;
const __be32 *remote;
enum v4l2_mbus_type bus_type;
union {
struct v4l2_of_bus_parallel parallel;
struct v4l2_of_bus_mipi_csi2 mipi_csi2;
} bus;
struct list_head head;
};
#ifdef CONFIG_OF
void v4l2_of_parse_endpoint(const struct device_node *node,
struct v4l2_of_endpoint *link);
struct device_node *v4l2_of_get_next_endpoint(const struct device_node *parent,
struct device_node *previous);
struct device_node *v4l2_of_get_remote_port_parent(
const struct device_node *node);
struct device_node *v4l2_of_get_remote_port(const struct device_node *node);
#else /* CONFIG_OF */
static inline int v4l2_of_parse_endpoint(const struct device_node *node,
struct v4l2_of_endpoint *link)
{
return -ENOSYS;
}
static inline struct device_node *v4l2_of_get_next_endpoint(
const struct device_node *parent,
struct device_node *previous)
{
return NULL;
}
static inline struct device_node *v4l2_of_get_remote_port_parent(
const struct device_node *node)
{
return NULL;
}
static inline struct device_node *v4l2_of_get_remote_port(
const struct device_node *node)
{
return NULL;
}
#endif /* CONFIG_OF */
#endif /* _V4L2_OF_H */