- 根目录:
- drivers
- media
- v4l2-core
- v4l2-of.c
/*
* V4L2 OF binding parsing library
*
* 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.
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/types.h>
#include <media/v4l2-of.h>
static int 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;
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;
unsigned int i;
for (i = 0; i < ARRAY_SIZE(bus->data_lanes); i++) {
lane = of_prop_next_u32(prop, lane, &v);
if (!lane)
break;
bus->data_lanes[i] = v;
}
bus->num_data_lanes = i;
}
prop = of_find_property(node, "lane-polarities", NULL);
if (prop) {
const __be32 *polarity = NULL;
unsigned int i;
for (i = 0; i < ARRAY_SIZE(bus->lane_polarities); i++) {
polarity = of_prop_next_u32(prop, polarity, &v);
if (!polarity)
break;
bus->lane_polarities[i] = v;
}
if (i < 1 + bus->num_data_lanes /* clock + data */) {
pr_warn("%s: too few lane-polarities entries (need %u, got %u)\n",
node->full_name, 1 + bus->num_data_lanes, i);
return -EINVAL;
}
}
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;
return 0;
}
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, "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, "pclk-sample", &v))
flags |= v ? V4L2_MBUS_PCLK_SAMPLE_RISING :
V4L2_MBUS_PCLK_SAMPLE_FALLING;
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;
if (!of_property_read_u32(node, "sync-on-green-active", &v))
flags |= v ? V4L2_MBUS_VIDEO_SOG_ACTIVE_HIGH :
V4L2_MBUS_VIDEO_SOG_ACTIVE_LOW;
bus->flags = flags;
}
/**
* 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.
*
* NOTE: This function does not parse properties the size of which is
* variable without a low fixed limit. Please use
* v4l2_of_alloc_parse_endpoint() in new drivers instead.
*
* Return: 0.
*/
int v4l2_of_parse_endpoint(const struct device_node *node,
struct v4l2_of_endpoint *endpoint)
{
int rval;
of_graph_parse_endpoint(node, &endpoint->base);
/* Zero fields from bus_type to until the end */
memset(&endpoint->bus_type, 0, sizeof(*endpoint) -
offsetof(typeof(*endpoint), bus_type));
rval = v4l2_of_parse_csi_bus(node, endpoint);
if (rval)
return rval;
/*
* 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);
return 0;
}
EXPORT_SYMBOL(v4l2_of_parse_endpoint);
/*
* v4l2_of_free_endpoint() - free the endpoint acquired by
* v4l2_of_alloc_parse_endpoint()
* @endpoint - the endpoint the resources of which are to be released
*
* It is safe to call this function with NULL argument or on an
* endpoint the parsing of which failed.
*/
void v4l2_of_free_endpoint(struct v4l2_of_endpoint *endpoint)
{
if (IS_ERR_OR_NULL(endpoint))
return;
kfree(endpoint->link_frequencies);
kfree(endpoint);
}
EXPORT_SYMBOL(v4l2_of_free_endpoint);
/**
* v4l2_of_alloc_parse_endpoint() - parse all endpoint node properties
* @node: pointer to endpoint device_node
*
* 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.
*
* v4l2_of_alloc_parse_endpoint() has two important differences to
* v4l2_of_parse_endpoint():
*
* 1. It also parses variable size data and
*
* 2. The memory it has allocated to store the variable size data must
* be freed using v4l2_of_free_endpoint() when no longer needed.
*
* Return: Pointer to v4l2_of_endpoint if successful, on error a
* negative error code.
*/
struct v4l2_of_endpoint *v4l2_of_alloc_parse_endpoint(
const struct device_node *node)
{
struct v4l2_of_endpoint *endpoint;
int len;
int rval;
endpoint = kzalloc(sizeof(*endpoint), GFP_KERNEL);
if (!endpoint)
return ERR_PTR(-ENOMEM);
rval = v4l2_of_parse_endpoint(node, endpoint);
if (rval < 0)
goto out_err;
if (of_get_property(node, "link-frequencies", &len)) {
endpoint->link_frequencies = kmalloc(len, GFP_KERNEL);
if (!endpoint->link_frequencies) {
rval = -ENOMEM;
goto out_err;
}
endpoint->nr_of_link_frequencies =
len / sizeof(*endpoint->link_frequencies);
rval = of_property_read_u64_array(
node, "link-frequencies", endpoint->link_frequencies,
endpoint->nr_of_link_frequencies);
if (rval < 0)
goto out_err;
}
return endpoint;
out_err:
v4l2_of_free_endpoint(endpoint);
return ERR_PTR(rval);
}
EXPORT_SYMBOL(v4l2_of_alloc_parse_endpoint);
/**
* v4l2_of_parse_link() - parse a link between two endpoints
* @node: pointer to the endpoint at the local end of the link
* @link: pointer to the V4L2 OF 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_of_put_link() to drop the references when done with the link.
*
* Return: 0 on success, or -ENOLINK if the remote endpoint can't be found.
*/
int v4l2_of_parse_link(const struct device_node *node,
struct v4l2_of_link *link)
{
struct device_node *np;
memset(link, 0, sizeof(*link));
np = of_get_parent(node);
of_property_read_u32(np, "reg", &link->local_port);
np = of_get_next_parent(np);
if (of_node_cmp(np->name, "ports") == 0)
np = of_get_next_parent(np);
link->local_node = np;
np = of_parse_phandle(node, "remote-endpoint", 0);
if (!np) {
of_node_put(link->local_node);
return -ENOLINK;
}
np = of_get_parent(np);
of_property_read_u32(np, "reg", &link->remote_port);
np = of_get_next_parent(np);
if (of_node_cmp(np->name, "ports") == 0)
np = of_get_next_parent(np);
link->remote_node = np;
return 0;
}
EXPORT_SYMBOL(v4l2_of_parse_link);
/**
* v4l2_of_put_link() - drop references to nodes in a link
* @link: pointer to the V4L2 OF 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_of_parse_link().
*/
void v4l2_of_put_link(struct v4l2_of_link *link)
{
of_node_put(link->local_node);
of_node_put(link->remote_node);
}
EXPORT_SYMBOL(v4l2_of_put_link);