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
  22 static 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
  61 static 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         if (!of_property_read_u32(node, "sync-on-green-active", &v))
 104                 flags |= v ? V4L2_MBUS_VIDEO_SOG_ACTIVE_HIGH :
 105                         V4L2_MBUS_VIDEO_SOG_ACTIVE_LOW;
 106
 107         bus->flags = flags;
 108
 109 }
 110
 111 /**
 112  * v4l2_of_parse_endpoint() - parse all endpoint node properties
 113  * @node: pointer to endpoint device_node
 114  * @endpoint: pointer to the V4L2 OF endpoint data structure
 115  *
 116  * All properties are optional. If none are found, we don't set any flags.
 117  * This means the port has a static configuration and no properties have
 118  * to be specified explicitly.
 119  * If any properties that identify the bus as parallel are found and
 120  * slave-mode isn't set, we set V4L2_MBUS_MASTER. Similarly, if we recognise
 121  * the bus as serial CSI-2 and clock-noncontinuous isn't set, we set the
 122  * V4L2_MBUS_CSI2_CONTINUOUS_CLOCK flag.
 123  * The caller should hold a reference to @node.
 124  *
 125  * Return: 0.
 126  */
 127 int v4l2_of_parse_endpoint(const struct device_node *node,
 128                            struct v4l2_of_endpoint *endpoint)
 129 {
 130         of_graph_parse_endpoint(node, &endpoint->base);
 131         endpoint->bus_type = 0;
 132         memset(&endpoint->bus, 0, sizeof(endpoint->bus));
 133
 134         v4l2_of_parse_csi_bus(node, endpoint);
 135         /*
 136          * Parse the parallel video bus properties only if none
 137          * of the MIPI CSI-2 specific properties were found.
 138          */
 139         if (endpoint->bus.mipi_csi2.flags == 0)
 140                 v4l2_of_parse_parallel_bus(node, endpoint);
 141
 142         return 0;
 143 }
 144 EXPORT_SYMBOL(v4l2_of_parse_endpoint);