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

   1/*
   2 * V4L2 OF binding parsing library
   3 *
   4 * Copyright (C) 2012 - 2013 Samsung Electronics Co., Ltd.
   5 * Author: Sylwester Nawrocki <s.nawrocki@samsung.com>
   6 *
   7 * Copyright (C) 2012 Renesas Electronics Corp.
   8 * Author: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
   9 *
  10 * This program is free software; you can redistribute it and/or modify
  11 * it under the terms of version 2 of the GNU General Public License as
  12 * published by the Free Software Foundation.
  13 */
  14#include <linux/kernel.h>
  15#include <linux/module.h>
  16#include <linux/of.h>
  17#include <linux/string.h>
  18#include <linux/types.h>
  19
  20#include <media/v4l2-of.h>
  21
  22static void v4l2_of_parse_csi_bus(const struct device_node *node,
  23                                  struct v4l2_of_endpoint *endpoint)
  24{
  25        struct v4l2_of_bus_mipi_csi2 *bus = &endpoint->bus.mipi_csi2;
  26        u32 data_lanes[ARRAY_SIZE(bus->data_lanes)];
  27        struct property *prop;
  28        bool have_clk_lane = false;
  29        unsigned int flags = 0;
  30        u32 v;
  31
  32        prop = of_find_property(node, "data-lanes", NULL);
  33        if (prop) {
  34                const __be32 *lane = NULL;
  35                int i;
  36
  37                for (i = 0; i < ARRAY_SIZE(data_lanes); i++) {
  38                        lane = of_prop_next_u32(prop, lane, &data_lanes[i]);
  39                        if (!lane)
  40                                break;
  41                }
  42                bus->num_data_lanes = i;
  43                while (i--)
  44                        bus->data_lanes[i] = data_lanes[i];
  45        }
  46
  47        if (!of_property_read_u32(node, "clock-lanes", &v)) {
  48                bus->clock_lane = v;
  49                have_clk_lane = true;
  50        }
  51
  52        if (of_get_property(node, "clock-noncontinuous", &v))
  53                flags |= V4L2_MBUS_CSI2_NONCONTINUOUS_CLOCK;
  54        else if (have_clk_lane || bus->num_data_lanes > 0)
  55                flags |= V4L2_MBUS_CSI2_CONTINUOUS_CLOCK;
  56
  57        bus->flags = flags;
  58        endpoint->bus_type = V4L2_MBUS_CSI2;
  59}
  60
  61static void v4l2_of_parse_parallel_bus(const struct device_node *node,
  62                                       struct v4l2_of_endpoint *endpoint)
  63{
  64        struct v4l2_of_bus_parallel *bus = &endpoint->bus.parallel;
  65        unsigned int flags = 0;
  66        u32 v;
  67
  68        if (!of_property_read_u32(node, "hsync-active", &v))
  69                flags |= v ? V4L2_MBUS_HSYNC_ACTIVE_HIGH :
  70                        V4L2_MBUS_HSYNC_ACTIVE_LOW;
  71
  72        if (!of_property_read_u32(node, "vsync-active", &v))
  73                flags |= v ? V4L2_MBUS_VSYNC_ACTIVE_HIGH :
  74                        V4L2_MBUS_VSYNC_ACTIVE_LOW;
  75
  76        if (!of_property_read_u32(node, "pclk-sample", &v))
  77                flags |= v ? V4L2_MBUS_PCLK_SAMPLE_RISING :
  78                        V4L2_MBUS_PCLK_SAMPLE_FALLING;
  79
  80        if (!of_property_read_u32(node, "field-even-active", &v))
  81                flags |= v ? V4L2_MBUS_FIELD_EVEN_HIGH :
  82                        V4L2_MBUS_FIELD_EVEN_LOW;
  83        if (flags)
  84                endpoint->bus_type = V4L2_MBUS_PARALLEL;
  85        else
  86                endpoint->bus_type = V4L2_MBUS_BT656;
  87
  88        if (!of_property_read_u32(node, "data-active", &v))
  89                flags |= v ? V4L2_MBUS_DATA_ACTIVE_HIGH :
  90                        V4L2_MBUS_DATA_ACTIVE_LOW;
  91
  92        if (of_get_property(node, "slave-mode", &v))
  93                flags |= V4L2_MBUS_SLAVE;
  94        else
  95                flags |= V4L2_MBUS_MASTER;
  96
  97        if (!of_property_read_u32(node, "bus-width", &v))
  98                bus->bus_width = v;
  99
 100        if (!of_property_read_u32(node, "data-shift", &v))
 101                bus->data_shift = v;
 102
 103        bus->flags = flags;
 104
 105}
 106
 107/**
 108 * v4l2_of_parse_endpoint() - parse all endpoint node properties
 109 * @node: pointer to endpoint device_node
 110 * @endpoint: pointer to the V4L2 OF endpoint data structure
 111 *
 112 * All properties are optional. If none are found, we don't set any flags.
 113 * This means the port has a static configuration and no properties have
 114 * to be specified explicitly.
 115 * If any properties that identify the bus as parallel are found and
 116 * slave-mode isn't set, we set V4L2_MBUS_MASTER. Similarly, if we recognise
 117 * the bus as serial CSI-2 and clock-noncontinuous isn't set, we set the
 118 * V4L2_MBUS_CSI2_CONTINUOUS_CLOCK flag.
 119 * The caller should hold a reference to @node.
 120 *
 121 * Return: 0.
 122 */
 123int v4l2_of_parse_endpoint(const struct device_node *node,
 124                           struct v4l2_of_endpoint *endpoint)
 125{
 126        of_graph_parse_endpoint(node, &endpoint->base);
 127        endpoint->bus_type = 0;
 128        memset(&endpoint->bus, 0, sizeof(endpoint->bus));
 129
 130        v4l2_of_parse_csi_bus(node, endpoint);
 131        /*
 132         * Parse the parallel video bus properties only if none
 133         * of the MIPI CSI-2 specific properties were found.
 134         */
 135        if (endpoint->bus.mipi_csi2.flags == 0)
 136                v4l2_of_parse_parallel_bus(node, endpoint);
 137
 138        return 0;
 139}
 140EXPORT_SYMBOL(v4l2_of_parse_endpoint);
 141