linux/drivers/media/v4l2-core/v4l2-of.c

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/*
* 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>
[media] v4l: of: Parse variable length properties --- link-frequencies The link-frequencies property is a variable length array of link frequencies in an endpoint. The array is needed by an increasing number of drivers, so it makes sense to add it to struct v4l2_of_endpoint. However, the length of the array is variable and the size of struct v4l2_of_endpoint is fixed since it is allocated by the caller. The options here are 1. to define a fixed maximum limit of link frequencies that has to be the global maximum of all boards. This is seen as problematic since the maximum could be largish, and everyone hitting the problem would need to submit a patch to fix it, or 2. parse the property in every driver. This doesn't sound appealing as two of the three implementations submitted to linux-media were wrong, and one of them was even merged before this was noticed, or 3. change the interface so that allocating and releasing memory according to the size of the array is possible. This is what the patch does. v4l2_of_alloc_parse_endpoint() is just like v4l2_of_parse_endpoint(), but it will allocate the memory resources needed to store struct v4l2_of_endpoint and the additional arrays pointed to by this struct. A corresponding release function v4l2_of_free_endpoint() is provided to release the memory allocated by v4l2_of_alloc_parse_endpoint(). In addition to this, the link-frequencies property is parsed as well, and the result is stored to struct v4l2_of_endpoint field link_frequencies. Signed-off-by: Sakari Ailus <sakari.ailus@iki.fi> Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Acked-by: Sylwester Nawrocki <s.nawrocki@samsung.com> Tested-by: Lad, Prabhakar <prabhakar.csengg@gmail.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
2015-03-22 20:48:26 +00:00
#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.
*
[media] v4l: of: Parse variable length properties --- link-frequencies The link-frequencies property is a variable length array of link frequencies in an endpoint. The array is needed by an increasing number of drivers, so it makes sense to add it to struct v4l2_of_endpoint. However, the length of the array is variable and the size of struct v4l2_of_endpoint is fixed since it is allocated by the caller. The options here are 1. to define a fixed maximum limit of link frequencies that has to be the global maximum of all boards. This is seen as problematic since the maximum could be largish, and everyone hitting the problem would need to submit a patch to fix it, or 2. parse the property in every driver. This doesn't sound appealing as two of the three implementations submitted to linux-media were wrong, and one of them was even merged before this was noticed, or 3. change the interface so that allocating and releasing memory according to the size of the array is possible. This is what the patch does. v4l2_of_alloc_parse_endpoint() is just like v4l2_of_parse_endpoint(), but it will allocate the memory resources needed to store struct v4l2_of_endpoint and the additional arrays pointed to by this struct. A corresponding release function v4l2_of_free_endpoint() is provided to release the memory allocated by v4l2_of_alloc_parse_endpoint(). In addition to this, the link-frequencies property is parsed as well, and the result is stored to struct v4l2_of_endpoint field link_frequencies. Signed-off-by: Sakari Ailus <sakari.ailus@iki.fi> Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Acked-by: Sylwester Nawrocki <s.nawrocki@samsung.com> Tested-by: Lad, Prabhakar <prabhakar.csengg@gmail.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
2015-03-22 20:48:26 +00:00
* 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);
[media] v4l: of: Parse variable length properties --- link-frequencies The link-frequencies property is a variable length array of link frequencies in an endpoint. The array is needed by an increasing number of drivers, so it makes sense to add it to struct v4l2_of_endpoint. However, the length of the array is variable and the size of struct v4l2_of_endpoint is fixed since it is allocated by the caller. The options here are 1. to define a fixed maximum limit of link frequencies that has to be the global maximum of all boards. This is seen as problematic since the maximum could be largish, and everyone hitting the problem would need to submit a patch to fix it, or 2. parse the property in every driver. This doesn't sound appealing as two of the three implementations submitted to linux-media were wrong, and one of them was even merged before this was noticed, or 3. change the interface so that allocating and releasing memory according to the size of the array is possible. This is what the patch does. v4l2_of_alloc_parse_endpoint() is just like v4l2_of_parse_endpoint(), but it will allocate the memory resources needed to store struct v4l2_of_endpoint and the additional arrays pointed to by this struct. A corresponding release function v4l2_of_free_endpoint() is provided to release the memory allocated by v4l2_of_alloc_parse_endpoint(). In addition to this, the link-frequencies property is parsed as well, and the result is stored to struct v4l2_of_endpoint field link_frequencies. Signed-off-by: Sakari Ailus <sakari.ailus@iki.fi> Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Acked-by: Sylwester Nawrocki <s.nawrocki@samsung.com> Tested-by: Lad, Prabhakar <prabhakar.csengg@gmail.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
2015-03-22 20:48:26 +00:00
/*
* 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);