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 int 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         struct property *prop;
  27         bool have_clk_lane = false;
  28         unsigned int flags = 0;
  29         u32 v;
  30
  31         prop = of_find_property(node, "data-lanes", NULL);
  32         if (prop) {
  33                 const __be32 *lane = NULL;
  34                 unsigned int i;
  35
  36                 for (i = 0; i < ARRAY_SIZE(bus->data_lanes); i++) {
  37                         lane = of_prop_next_u32(prop, lane, &v);
  38                         if (!lane)
  39                                 break;
  40                         bus->data_lanes[i] = v;
  41                 }
  42                 bus->num_data_lanes = i;
  43         }
  44
  45         prop = of_find_property(node, "lane-polarities", NULL);
  46         if (prop) {
  47                 const __be32 *polarity = NULL;
  48                 unsigned int i;
  49
  50                 for (i = 0; i < ARRAY_SIZE(bus->lane_polarities); i++) {
  51                         polarity = of_prop_next_u32(prop, polarity, &v);
  52                         if (!polarity)
  53                                 break;
  54                         bus->lane_polarities[i] = v;
  55                 }
  56
  57                 if (i < 1 + bus->num_data_lanes /* clock + data */) {
  58                         pr_warn("%s: too few lane-polarities entries (need %u, got %u)\n",
  59                                 node->full_name, 1 + bus->num_data_lanes, i);
  60                         return -EINVAL;
  61                 }
  62         }
  63
  64         if (!of_property_read_u32(node, "clock-lanes", &v)) {
  65                 bus->clock_lane = v;
  66                 have_clk_lane = true;
  67         }
  68
  69         if (of_get_property(node, "clock-noncontinuous", &v))
  70                 flags |= V4L2_MBUS_CSI2_NONCONTINUOUS_CLOCK;
  71         else if (have_clk_lane || bus->num_data_lanes > 0)
  72                 flags |= V4L2_MBUS_CSI2_CONTINUOUS_CLOCK;
  73
  74         bus->flags = flags;
  75         endpoint->bus_type = V4L2_MBUS_CSI2;
  76
  77         return 0;
  78 }
  79
  80 static void v4l2_of_parse_parallel_bus(const struct device_node *node,
  81                                        struct v4l2_of_endpoint *endpoint)
  82 {
  83         struct v4l2_of_bus_parallel *bus = &endpoint->bus.parallel;
  84         unsigned int flags = 0;
  85         u32 v;
  86
  87         if (!of_property_read_u32(node, "hsync-active", &v))
  88                 flags |= v ? V4L2_MBUS_HSYNC_ACTIVE_HIGH :
  89                         V4L2_MBUS_HSYNC_ACTIVE_LOW;
  90
  91         if (!of_property_read_u32(node, "vsync-active", &v))
  92                 flags |= v ? V4L2_MBUS_VSYNC_ACTIVE_HIGH :
  93                         V4L2_MBUS_VSYNC_ACTIVE_LOW;
  94
  95         if (!of_property_read_u32(node, "pclk-sample", &v))
  96                 flags |= v ? V4L2_MBUS_PCLK_SAMPLE_RISING :
  97                         V4L2_MBUS_PCLK_SAMPLE_FALLING;
  98
  99         if (!of_property_read_u32(node, "field-even-active", &v))
 100                 flags |= v ? V4L2_MBUS_FIELD_EVEN_HIGH :
 101                         V4L2_MBUS_FIELD_EVEN_LOW;
 102         if (flags)
 103                 endpoint->bus_type = V4L2_MBUS_PARALLEL;
 104         else
 105                 endpoint->bus_type = V4L2_MBUS_BT656;
 106
 107         if (!of_property_read_u32(node, "data-active", &v))
 108                 flags |= v ? V4L2_MBUS_DATA_ACTIVE_HIGH :
 109                         V4L2_MBUS_DATA_ACTIVE_LOW;
 110
 111         if (of_get_property(node, "slave-mode", &v))
 112                 flags |= V4L2_MBUS_SLAVE;
 113         else
 114                 flags |= V4L2_MBUS_MASTER;
 115
 116         if (!of_property_read_u32(node, "bus-width", &v))
 117                 bus->bus_width = v;
 118
 119         if (!of_property_read_u32(node, "data-shift", &v))
 120                 bus->data_shift = v;
 121
 122         if (!of_property_read_u32(node, "sync-on-green-active", &v))
 123                 flags |= v ? V4L2_MBUS_VIDEO_SOG_ACTIVE_HIGH :
 124                         V4L2_MBUS_VIDEO_SOG_ACTIVE_LOW;
 125
 126         bus->flags = flags;
 127
 128 }
 129
 130 /**
 131  * v4l2_of_parse_endpoint() - parse all endpoint node properties
 132  * @node: pointer to endpoint device_node
 133  * @endpoint: pointer to the V4L2 OF endpoint data structure
 134  *
 135  * All properties are optional. If none are found, we don't set any flags.
 136  * This means the port has a static configuration and no properties have
 137  * to be specified explicitly.
 138  * If any properties that identify the bus as parallel are found and
 139  * slave-mode isn't set, we set V4L2_MBUS_MASTER. Similarly, if we recognise
 140  * the bus as serial CSI-2 and clock-noncontinuous isn't set, we set the
 141  * V4L2_MBUS_CSI2_CONTINUOUS_CLOCK flag.
 142  * The caller should hold a reference to @node.
 143  *
 144  * Return: 0.
 145  */
 146 int v4l2_of_parse_endpoint(const struct device_node *node,
 147                            struct v4l2_of_endpoint *endpoint)
 148 {
 149         int rval;
 150
 151         of_graph_parse_endpoint(node, &endpoint->base);
 152         endpoint->bus_type = 0;
 153         memset(&endpoint->bus, 0, sizeof(endpoint->bus));
 154
 155         rval = v4l2_of_parse_csi_bus(node, endpoint);
 156         if (rval)
 157                 return rval;
 158         /*
 159          * Parse the parallel video bus properties only if none
 160          * of the MIPI CSI-2 specific properties were found.
 161          */
 162         if (endpoint->bus.mipi_csi2.flags == 0)
 163                 v4l2_of_parse_parallel_bus(node, endpoint);
 164
 165         return 0;
 166 }
 167 EXPORT_SYMBOL(v4l2_of_parse_endpoint);
 168
 169 /**
 170  * v4l2_of_parse_link() - parse a link between two endpoints
 171  * @node: pointer to the endpoint at the local end of the link
 172  * @link: pointer to the V4L2 OF link data structure
 173  *
 174  * Fill the link structure with the local and remote nodes and port numbers.
 175  * The local_node and remote_node fields are set to point to the local and
 176  * remote port's parent nodes respectively (the port parent node being the
 177  * parent node of the port node if that node isn't a 'ports' node, or the
 178  * grand-parent node of the port node otherwise).
 179  *
 180  * A reference is taken to both the local and remote nodes, the caller must use
 181  * v4l2_of_put_link() to drop the references when done with the link.
 182  *
 183  * Return: 0 on success, or -ENOLINK if the remote endpoint can't be found.
 184  */
 185 int v4l2_of_parse_link(const struct device_node *node,
 186                        struct v4l2_of_link *link)
 187 {
 188         struct device_node *np;
 189
 190         memset(link, 0, sizeof(*link));
 191
 192         np = of_get_parent(node);
 193         of_property_read_u32(np, "reg", &link->local_port);
 194         np = of_get_next_parent(np);
 195         if (of_node_cmp(np->name, "ports") == 0)
 196                 np = of_get_next_parent(np);
 197         link->local_node = np;
 198
 199         np = of_parse_phandle(node, "remote-endpoint", 0);
 200         if (!np) {
 201                 of_node_put(link->local_node);
 202                 return -ENOLINK;
 203         }
 204
 205         np = of_get_parent(np);
 206         of_property_read_u32(np, "reg", &link->remote_port);
 207         np = of_get_next_parent(np);
 208         if (of_node_cmp(np->name, "ports") == 0)
 209                 np = of_get_next_parent(np);
 210         link->remote_node = np;
 211
 212         return 0;
 213 }
 214 EXPORT_SYMBOL(v4l2_of_parse_link);
 215
 216 /**
 217  * v4l2_of_put_link() - drop references to nodes in a link
 218  * @link: pointer to the V4L2 OF link data structure
 219  *
 220  * Drop references to the local and remote nodes in the link. This function must
 221  * be called on every link parsed with v4l2_of_parse_link().
 222  */
 223 void v4l2_of_put_link(struct v4l2_of_link *link)
 224 {
 225         of_node_put(link->local_node);
 226         of_node_put(link->remote_node);
 227 }
 228 EXPORT_SYMBOL(v4l2_of_put_link);