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[media] v4l: fwnode: Support generic fwnode for parsing standardised properties

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The fwnode_handle is a more generic way than OF device_node to describe
firmware nodes. Instead of the OF API, use more generic fwnode API to
obtain the same information.

As the V4L2 fwnode support will be required by a small minority of e.g.
ACPI based systems (the same might actually go for OF), make this a module
instead of embedding it in the videodev module.

The origins of the V4L2 fwnode framework is in the V4L2 OF framework.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Tested-by: Hans Verkuil <hans.verkuil@cisco.com>
Tested-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
This commit is contained in:
Sakari Ailus 2016-08-12 08:05:51 -03:00 committed by Mauro Carvalho Chehab
parent 614d651e1a
commit ca50c197bd
4 changed files with 453 additions and 0 deletions
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3
drivers/media/v4l2-core/Kconfig
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@ -55,6 +55,9 @@ config V4L2_FLASH_LED_CLASS
When in doubt, say N.
config V4L2_FWNODE
tristate
# Used by drivers that need Videobuf modules
config VIDEOBUF_GEN
tristate

1
drivers/media/v4l2-core/Makefile
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@ -13,6 +13,7 @@ endif
ifeq ($(CONFIG_OF),y)
videodev-objs += v4l2-of.o
endif
obj-$(CONFIG_V4L2_FWNODE) += v4l2-fwnode.o
ifeq ($(CONFIG_TRACEPOINTS),y)
videodev-objs += vb2-trace.o v4l2-trace.o
endif

345
drivers/media/v4l2-core/v4l2-fwnode.c Normal file
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@ -0,0 +1,345 @@
/*
* V4L2 fwnode binding parsing library
*
* The origins of the V4L2 fwnode library are in V4L2 OF library that
* formerly was located in v4l2-of.c.
*
* 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.
*/
#include <linux/acpi.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/property.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/types.h>
#include <media/v4l2-fwnode.h>
static int v4l2_fwnode_endpoint_parse_csi_bus(struct fwnode_handle *fwnode,
struct v4l2_fwnode_endpoint *vep)
{
struct v4l2_fwnode_bus_mipi_csi2 *bus = &vep->bus.mipi_csi2;
bool have_clk_lane = false;
unsigned int flags = 0, lanes_used = 0;
unsigned int i;
u32 v;
int rval;
rval = fwnode_property_read_u32_array(fwnode, "data-lanes", NULL, 0);
if (rval > 0) {
u32 array[ARRAY_SIZE(bus->data_lanes)];
bus->num_data_lanes =
min_t(int, ARRAY_SIZE(bus->data_lanes), rval);
fwnode_property_read_u32_array(fwnode, "data-lanes", array,
bus->num_data_lanes);
for (i = 0; i < bus->num_data_lanes; i++) {
if (lanes_used & BIT(array[i]))
pr_warn("duplicated lane %u in data-lanes\n",
array[i]);
lanes_used |= BIT(array[i]);
bus->data_lanes[i] = array[i];
}
}
rval = fwnode_property_read_u32_array(fwnode, "lane-polarities", NULL,
0);
if (rval > 0) {
u32 array[ARRAY_SIZE(bus->lane_polarities)];
if (rval < 1 + bus->num_data_lanes /* clock + data */) {
pr_warn("too few lane-polarities entries (need %u, got %u)\n",
1 + bus->num_data_lanes, rval);
return -EINVAL;
}
fwnode_property_read_u32_array(fwnode, "lane-polarities", array,
1 + bus->num_data_lanes);
for (i = 0; i < 1 + bus->num_data_lanes; i++)
bus->lane_polarities[i] = array[i];
}
if (!fwnode_property_read_u32(fwnode, "clock-lanes", &v)) {
if (lanes_used & BIT(v))
pr_warn("duplicated lane %u in clock-lanes\n", v);
lanes_used |= BIT(v);
bus->clock_lane = v;
have_clk_lane = true;
}
if (fwnode_property_present(fwnode, "clock-noncontinuous"))
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;
vep->bus_type = V4L2_MBUS_CSI2;
return 0;
}
static void v4l2_fwnode_endpoint_parse_parallel_bus(
struct fwnode_handle *fwnode, struct v4l2_fwnode_endpoint *vep)
{
struct v4l2_fwnode_bus_parallel *bus = &vep->bus.parallel;
unsigned int flags = 0;
u32 v;
if (!fwnode_property_read_u32(fwnode, "hsync-active", &v))
flags |= v ? V4L2_MBUS_HSYNC_ACTIVE_HIGH :
V4L2_MBUS_HSYNC_ACTIVE_LOW;
if (!fwnode_property_read_u32(fwnode, "vsync-active", &v))
flags |= v ? V4L2_MBUS_VSYNC_ACTIVE_HIGH :
V4L2_MBUS_VSYNC_ACTIVE_LOW;
if (!fwnode_property_read_u32(fwnode, "field-even-active", &v))
flags |= v ? V4L2_MBUS_FIELD_EVEN_HIGH :
V4L2_MBUS_FIELD_EVEN_LOW;
if (flags)
vep->bus_type = V4L2_MBUS_PARALLEL;
else
vep->bus_type = V4L2_MBUS_BT656;
if (!fwnode_property_read_u32(fwnode, "pclk-sample", &v))
flags |= v ? V4L2_MBUS_PCLK_SAMPLE_RISING :
V4L2_MBUS_PCLK_SAMPLE_FALLING;
if (!fwnode_property_read_u32(fwnode, "data-active", &v))
flags |= v ? V4L2_MBUS_DATA_ACTIVE_HIGH :
V4L2_MBUS_DATA_ACTIVE_LOW;
if (fwnode_property_present(fwnode, "slave-mode"))
flags |= V4L2_MBUS_SLAVE;
else
flags |= V4L2_MBUS_MASTER;
if (!fwnode_property_read_u32(fwnode, "bus-width", &v))
bus->bus_width = v;
if (!fwnode_property_read_u32(fwnode, "data-shift", &v))
bus->data_shift = v;
if (!fwnode_property_read_u32(fwnode, "sync-on-green-active", &v))
flags |= v ? V4L2_MBUS_VIDEO_SOG_ACTIVE_HIGH :
V4L2_MBUS_VIDEO_SOG_ACTIVE_LOW;
bus->flags = flags;
}
/**
* 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)
{
int rval;
fwnode_graph_parse_endpoint(fwnode, &vep->base);
/* Zero fields from bus_type to until the end */
memset(&vep->bus_type, 0, sizeof(*vep) -
offsetof(typeof(*vep), bus_type));
rval = v4l2_fwnode_endpoint_parse_csi_bus(fwnode, vep);
if (rval)
return rval;
/*
* Parse the parallel video bus properties only if none
* of the MIPI CSI-2 specific properties were found.
*/
if (vep->bus.mipi_csi2.flags == 0)
v4l2_fwnode_endpoint_parse_parallel_bus(fwnode, vep);
return 0;
}
EXPORT_SYMBOL_GPL(v4l2_fwnode_endpoint_parse);
/*
* 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)
{
if (IS_ERR_OR_NULL(vep))
return;
kfree(vep->link_frequencies);
kfree(vep);
}
EXPORT_SYMBOL_GPL(v4l2_fwnode_endpoint_free);
/**
* 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)
{
struct v4l2_fwnode_endpoint *vep;
int rval;
vep = kzalloc(sizeof(*vep), GFP_KERNEL);
if (!vep)
return ERR_PTR(-ENOMEM);
rval = v4l2_fwnode_endpoint_parse(fwnode, vep);
if (rval < 0)
goto out_err;
rval = fwnode_property_read_u64_array(fwnode, "link-frequencies",
NULL, 0);
if (rval < 0)
goto out_err;
vep->link_frequencies =
kmalloc_array(rval, sizeof(*vep->link_frequencies), GFP_KERNEL);
if (!vep->link_frequencies) {
rval = -ENOMEM;
goto out_err;
}
vep->nr_of_link_frequencies = rval;
rval = fwnode_property_read_u64_array(fwnode, "link-frequencies",
vep->link_frequencies,
vep->nr_of_link_frequencies);
if (rval < 0)
goto out_err;
return vep;
out_err:
v4l2_fwnode_endpoint_free(vep);
return ERR_PTR(rval);
}
EXPORT_SYMBOL_GPL(v4l2_fwnode_endpoint_alloc_parse);
/**
* v4l2_fwnode_endpoint_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_endpoint_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)
{
const char *port_prop = is_of_node(__fwnode) ? "reg" : "port";
struct fwnode_handle *fwnode;
memset(link, 0, sizeof(*link));
fwnode = fwnode_get_parent(__fwnode);
fwnode_property_read_u32(fwnode, port_prop, &link->local_port);
fwnode = fwnode_get_next_parent(fwnode);
if (is_of_node(fwnode) &&
of_node_cmp(to_of_node(fwnode)->name, "ports") == 0)
fwnode = fwnode_get_next_parent(fwnode);
link->local_node = fwnode;
fwnode = fwnode_graph_get_remote_endpoint(__fwnode);
if (!fwnode) {
fwnode_handle_put(fwnode);
return -ENOLINK;
}
fwnode = fwnode_get_parent(fwnode);
fwnode_property_read_u32(fwnode, port_prop, &link->remote_port);
fwnode = fwnode_get_next_parent(fwnode);
if (is_of_node(fwnode) &&
of_node_cmp(to_of_node(fwnode)->name, "ports") == 0)
fwnode = fwnode_get_next_parent(fwnode);
link->remote_node = fwnode;
return 0;
}
EXPORT_SYMBOL_GPL(v4l2_fwnode_parse_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)
{
fwnode_handle_put(link->local_node);
fwnode_handle_put(link->remote_node);
}
EXPORT_SYMBOL_GPL(v4l2_fwnode_put_link);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Sakari Ailus <sakari.ailus@linux.intel.com>");
MODULE_AUTHOR("Sylwester Nawrocki <s.nawrocki@samsung.com>");
MODULE_AUTHOR("Guennadi Liakhovetski <g.liakhovetski@gmx.de>");

104
include/media/v4l2-fwnode.h Normal file
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@ -0,0 +1,104 @@
/*
* 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_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[4];
unsigned char clock_lane;
unsigned short num_data_lanes;
bool lane_polarities[5];
};
/**
* 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_endpoint - the endpoint data structure
* @base: fwnode endpoint of the v4l2_fwnode
* @bus_type: bus type
* @bus: bus configuration data structure
* @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_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;
};
int v4l2_fwnode_endpoint_parse(struct fwnode_handle *fwnode,
struct v4l2_fwnode_endpoint *vep);
struct v4l2_fwnode_endpoint *v4l2_fwnode_endpoint_alloc_parse(
struct fwnode_handle *fwnode);
void v4l2_fwnode_endpoint_free(struct v4l2_fwnode_endpoint *vep);
int v4l2_fwnode_parse_link(struct fwnode_handle *fwnode,
struct v4l2_fwnode_link *link);
void v4l2_fwnode_put_link(struct v4l2_fwnode_link *link);
#endif /* _V4L2_FWNODE_H */