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![Javier Martinez Canillas](/assets/img/avatar_default.png)
The v4l2_of_parse_endpoint function kernel-doc says that the return value is always 0. But that is not true since the function can fail and a error negative code is returned on failure. So correct the kernel-doc to match. Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com> Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
316 lines
9.1 KiB
C
316 lines
9.1 KiB
C
/*
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* V4L2 OF binding parsing library
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*
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* Copyright (C) 2012 - 2013 Samsung Electronics Co., Ltd.
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* Author: Sylwester Nawrocki <s.nawrocki@samsung.com>
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*
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* Copyright (C) 2012 Renesas Electronics Corp.
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* Author: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of version 2 of the GNU General Public License as
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* published by the Free Software Foundation.
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*/
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/of.h>
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#include <linux/slab.h>
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#include <linux/string.h>
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#include <linux/types.h>
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#include <media/v4l2-of.h>
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static int v4l2_of_parse_csi_bus(const struct device_node *node,
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struct v4l2_of_endpoint *endpoint)
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{
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struct v4l2_of_bus_mipi_csi2 *bus = &endpoint->bus.mipi_csi2;
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struct property *prop;
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bool have_clk_lane = false;
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unsigned int flags = 0;
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u32 v;
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prop = of_find_property(node, "data-lanes", NULL);
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if (prop) {
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const __be32 *lane = NULL;
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unsigned int i;
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for (i = 0; i < ARRAY_SIZE(bus->data_lanes); i++) {
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lane = of_prop_next_u32(prop, lane, &v);
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if (!lane)
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break;
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bus->data_lanes[i] = v;
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}
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bus->num_data_lanes = i;
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}
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prop = of_find_property(node, "lane-polarities", NULL);
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if (prop) {
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const __be32 *polarity = NULL;
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unsigned int i;
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for (i = 0; i < ARRAY_SIZE(bus->lane_polarities); i++) {
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polarity = of_prop_next_u32(prop, polarity, &v);
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if (!polarity)
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break;
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bus->lane_polarities[i] = v;
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}
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if (i < 1 + bus->num_data_lanes /* clock + data */) {
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pr_warn("%s: too few lane-polarities entries (need %u, got %u)\n",
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node->full_name, 1 + bus->num_data_lanes, i);
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return -EINVAL;
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}
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}
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if (!of_property_read_u32(node, "clock-lanes", &v)) {
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bus->clock_lane = v;
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have_clk_lane = true;
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}
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if (of_get_property(node, "clock-noncontinuous", &v))
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flags |= V4L2_MBUS_CSI2_NONCONTINUOUS_CLOCK;
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else if (have_clk_lane || bus->num_data_lanes > 0)
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flags |= V4L2_MBUS_CSI2_CONTINUOUS_CLOCK;
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bus->flags = flags;
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endpoint->bus_type = V4L2_MBUS_CSI2;
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return 0;
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}
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static void v4l2_of_parse_parallel_bus(const struct device_node *node,
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struct v4l2_of_endpoint *endpoint)
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{
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struct v4l2_of_bus_parallel *bus = &endpoint->bus.parallel;
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unsigned int flags = 0;
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u32 v;
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if (!of_property_read_u32(node, "hsync-active", &v))
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flags |= v ? V4L2_MBUS_HSYNC_ACTIVE_HIGH :
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V4L2_MBUS_HSYNC_ACTIVE_LOW;
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if (!of_property_read_u32(node, "vsync-active", &v))
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flags |= v ? V4L2_MBUS_VSYNC_ACTIVE_HIGH :
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V4L2_MBUS_VSYNC_ACTIVE_LOW;
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if (!of_property_read_u32(node, "field-even-active", &v))
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flags |= v ? V4L2_MBUS_FIELD_EVEN_HIGH :
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V4L2_MBUS_FIELD_EVEN_LOW;
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if (flags)
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endpoint->bus_type = V4L2_MBUS_PARALLEL;
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else
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endpoint->bus_type = V4L2_MBUS_BT656;
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if (!of_property_read_u32(node, "pclk-sample", &v))
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flags |= v ? V4L2_MBUS_PCLK_SAMPLE_RISING :
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V4L2_MBUS_PCLK_SAMPLE_FALLING;
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if (!of_property_read_u32(node, "data-active", &v))
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flags |= v ? V4L2_MBUS_DATA_ACTIVE_HIGH :
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V4L2_MBUS_DATA_ACTIVE_LOW;
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if (of_get_property(node, "slave-mode", &v))
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flags |= V4L2_MBUS_SLAVE;
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else
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flags |= V4L2_MBUS_MASTER;
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if (!of_property_read_u32(node, "bus-width", &v))
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bus->bus_width = v;
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if (!of_property_read_u32(node, "data-shift", &v))
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bus->data_shift = v;
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if (!of_property_read_u32(node, "sync-on-green-active", &v))
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flags |= v ? V4L2_MBUS_VIDEO_SOG_ACTIVE_HIGH :
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V4L2_MBUS_VIDEO_SOG_ACTIVE_LOW;
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bus->flags = flags;
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}
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/**
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* v4l2_of_parse_endpoint() - parse all endpoint node properties
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* @node: pointer to endpoint device_node
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* @endpoint: pointer to the V4L2 OF endpoint data structure
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*
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* All properties are optional. If none are found, we don't set any flags.
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* This means the port has a static configuration and no properties have
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* to be specified explicitly.
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* If any properties that identify the bus as parallel are found and
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* slave-mode isn't set, we set V4L2_MBUS_MASTER. Similarly, if we recognise
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* the bus as serial CSI-2 and clock-noncontinuous isn't set, we set the
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* V4L2_MBUS_CSI2_CONTINUOUS_CLOCK flag.
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* The caller should hold a reference to @node.
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*
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* NOTE: This function does not parse properties the size of which is
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* variable without a low fixed limit. Please use
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* v4l2_of_alloc_parse_endpoint() in new drivers instead.
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*
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* Return: 0 on success or a negative error code on failure.
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*/
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int v4l2_of_parse_endpoint(const struct device_node *node,
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struct v4l2_of_endpoint *endpoint)
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{
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int rval;
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of_graph_parse_endpoint(node, &endpoint->base);
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/* Zero fields from bus_type to until the end */
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memset(&endpoint->bus_type, 0, sizeof(*endpoint) -
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offsetof(typeof(*endpoint), bus_type));
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rval = v4l2_of_parse_csi_bus(node, endpoint);
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if (rval)
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return rval;
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/*
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* Parse the parallel video bus properties only if none
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* of the MIPI CSI-2 specific properties were found.
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*/
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if (endpoint->bus.mipi_csi2.flags == 0)
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v4l2_of_parse_parallel_bus(node, endpoint);
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return 0;
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}
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EXPORT_SYMBOL(v4l2_of_parse_endpoint);
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/*
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* v4l2_of_free_endpoint() - free the endpoint acquired by
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* v4l2_of_alloc_parse_endpoint()
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* @endpoint - the endpoint the resources of which are to be released
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*
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* It is safe to call this function with NULL argument or on an
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* endpoint the parsing of which failed.
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*/
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void v4l2_of_free_endpoint(struct v4l2_of_endpoint *endpoint)
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{
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if (IS_ERR_OR_NULL(endpoint))
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return;
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kfree(endpoint->link_frequencies);
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kfree(endpoint);
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}
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EXPORT_SYMBOL(v4l2_of_free_endpoint);
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/**
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* v4l2_of_alloc_parse_endpoint() - parse all endpoint node properties
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* @node: pointer to endpoint device_node
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*
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* All properties are optional. If none are found, we don't set any flags.
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* This means the port has a static configuration and no properties have
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* to be specified explicitly.
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* If any properties that identify the bus as parallel are found and
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* slave-mode isn't set, we set V4L2_MBUS_MASTER. Similarly, if we recognise
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* the bus as serial CSI-2 and clock-noncontinuous isn't set, we set the
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* V4L2_MBUS_CSI2_CONTINUOUS_CLOCK flag.
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* The caller should hold a reference to @node.
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*
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* v4l2_of_alloc_parse_endpoint() has two important differences to
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* v4l2_of_parse_endpoint():
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*
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* 1. It also parses variable size data and
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*
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* 2. The memory it has allocated to store the variable size data must
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* be freed using v4l2_of_free_endpoint() when no longer needed.
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*
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* Return: Pointer to v4l2_of_endpoint if successful, on error a
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* negative error code.
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*/
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struct v4l2_of_endpoint *v4l2_of_alloc_parse_endpoint(
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const struct device_node *node)
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{
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struct v4l2_of_endpoint *endpoint;
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int len;
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int rval;
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endpoint = kzalloc(sizeof(*endpoint), GFP_KERNEL);
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if (!endpoint)
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return ERR_PTR(-ENOMEM);
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rval = v4l2_of_parse_endpoint(node, endpoint);
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if (rval < 0)
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goto out_err;
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if (of_get_property(node, "link-frequencies", &len)) {
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endpoint->link_frequencies = kmalloc(len, GFP_KERNEL);
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if (!endpoint->link_frequencies) {
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rval = -ENOMEM;
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goto out_err;
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}
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endpoint->nr_of_link_frequencies =
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len / sizeof(*endpoint->link_frequencies);
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rval = of_property_read_u64_array(
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node, "link-frequencies", endpoint->link_frequencies,
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endpoint->nr_of_link_frequencies);
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if (rval < 0)
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goto out_err;
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}
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return endpoint;
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out_err:
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v4l2_of_free_endpoint(endpoint);
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return ERR_PTR(rval);
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}
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EXPORT_SYMBOL(v4l2_of_alloc_parse_endpoint);
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/**
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* v4l2_of_parse_link() - parse a link between two endpoints
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* @node: pointer to the endpoint at the local end of the link
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* @link: pointer to the V4L2 OF link data structure
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*
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* Fill the link structure with the local and remote nodes and port numbers.
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* The local_node and remote_node fields are set to point to the local and
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* remote port's parent nodes respectively (the port parent node being the
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* parent node of the port node if that node isn't a 'ports' node, or the
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* grand-parent node of the port node otherwise).
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*
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* A reference is taken to both the local and remote nodes, the caller must use
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* v4l2_of_put_link() to drop the references when done with the link.
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*
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* Return: 0 on success, or -ENOLINK if the remote endpoint can't be found.
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*/
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int v4l2_of_parse_link(const struct device_node *node,
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struct v4l2_of_link *link)
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{
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struct device_node *np;
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memset(link, 0, sizeof(*link));
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np = of_get_parent(node);
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of_property_read_u32(np, "reg", &link->local_port);
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np = of_get_next_parent(np);
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if (of_node_cmp(np->name, "ports") == 0)
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np = of_get_next_parent(np);
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link->local_node = np;
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np = of_parse_phandle(node, "remote-endpoint", 0);
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if (!np) {
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of_node_put(link->local_node);
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return -ENOLINK;
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}
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np = of_get_parent(np);
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of_property_read_u32(np, "reg", &link->remote_port);
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np = of_get_next_parent(np);
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if (of_node_cmp(np->name, "ports") == 0)
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np = of_get_next_parent(np);
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link->remote_node = np;
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return 0;
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}
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EXPORT_SYMBOL(v4l2_of_parse_link);
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/**
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* v4l2_of_put_link() - drop references to nodes in a link
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* @link: pointer to the V4L2 OF link data structure
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*
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* Drop references to the local and remote nodes in the link. This function must
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* be called on every link parsed with v4l2_of_parse_link().
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*/
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void v4l2_of_put_link(struct v4l2_of_link *link)
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{
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of_node_put(link->local_node);
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of_node_put(link->remote_node);
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}
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EXPORT_SYMBOL(v4l2_of_put_link);
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