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         struct device_node *port_node = of_get_parent(node);
 131
 132         memset(endpoint, 0, offsetof(struct v4l2_of_endpoint, head));
 133
 134         endpoint->local_node = node;
 135         /*
 136          * It doesn't matter whether the two calls below succeed.
 137          * If they don't then the default value 0 is used.
 138          */
 139         of_property_read_u32(port_node, "reg", &endpoint->port);
 140         of_property_read_u32(node, "reg", &endpoint->id);
 141
 142         v4l2_of_parse_csi_bus(node, endpoint);
 143         /*
 144          * Parse the parallel video bus properties only if none
 145          * of the MIPI CSI-2 specific properties were found.
 146          */
 147         if (endpoint->bus.mipi_csi2.flags == 0)
 148                 v4l2_of_parse_parallel_bus(node, endpoint);
 149
 150         of_node_put(port_node);
 151
 152         return 0;
 153 }
 154 EXPORT_SYMBOL(v4l2_of_parse_endpoint);
 155
 156 /**
 157  * v4l2_of_get_next_endpoint() - get next endpoint node
 158  * @parent: pointer to the parent device node
 159  * @prev: previous endpoint node, or NULL to get first
 160  *
 161  * Return: An 'endpoint' node pointer with refcount incremented. Refcount
 162  * of the passed @prev node is not decremented, the caller have to use
 163  * of_node_put() on it when done.
 164  */
 165 struct device_node *v4l2_of_get_next_endpoint(const struct device_node *parent,
 166                                         struct device_node *prev)
 167 {
 168         struct device_node *endpoint;
 169         struct device_node *port = NULL;
 170
 171         if (!parent)
 172                 return NULL;
 173
 174         if (!prev) {
 175                 struct device_node *node;
 176                 /*
 177                  * It's the first call, we have to find a port subnode
 178                  * within this node or within an optional 'ports' node.
 179                  */
 180                 node = of_get_child_by_name(parent, "ports");
 181                 if (node)
 182                         parent = node;
 183
 184                 port = of_get_child_by_name(parent, "port");
 185
 186                 if (port) {
 187                         /* Found a port, get an endpoint. */
 188                         endpoint = of_get_next_child(port, NULL);
 189                         of_node_put(port);
 190                 } else {
 191                         endpoint = NULL;
 192                 }
 193
 194                 if (!endpoint)
 195                         pr_err("%s(): no endpoint nodes specified for %s\n",
 196                                __func__, parent->full_name);
 197                 of_node_put(node);
 198         } else {
 199                 port = of_get_parent(prev);
 200                 if (!port)
 201                         /* Hm, has someone given us the root node ?... */
 202                         return NULL;
 203
 204                 /* Avoid dropping prev node refcount to 0. */
 205                 of_node_get(prev);
 206                 endpoint = of_get_next_child(port, prev);
 207                 if (endpoint) {
 208                         of_node_put(port);
 209                         return endpoint;
 210                 }
 211
 212                 /* No more endpoints under this port, try the next one. */
 213                 do {
 214                         port = of_get_next_child(parent, port);
 215                         if (!port)
 216                                 return NULL;
 217                 } while (of_node_cmp(port->name, "port"));
 218
 219                 /* Pick up the first endpoint in this port. */
 220                 endpoint = of_get_next_child(port, NULL);
 221                 of_node_put(port);
 222         }
 223
 224         return endpoint;
 225 }
 226 EXPORT_SYMBOL(v4l2_of_get_next_endpoint);
 227
 228 /**
 229  * v4l2_of_get_remote_port_parent() - get remote port's parent node
 230  * @node: pointer to a local endpoint device_node
 231  *
 232  * Return: Remote device node associated with remote endpoint node linked
 233  *         to @node. Use of_node_put() on it when done.
 234  */
 235 struct device_node *v4l2_of_get_remote_port_parent(
 236                                const struct device_node *node)
 237 {
 238         struct device_node *np;
 239         unsigned int depth;
 240
 241         /* Get remote endpoint node. */
 242         np = of_parse_phandle(node, "remote-endpoint", 0);
 243
 244         /* Walk 3 levels up only if there is 'ports' node. */
 245         for (depth = 3; depth && np; depth--) {
 246                 np = of_get_next_parent(np);
 247                 if (depth == 2 && of_node_cmp(np->name, "ports"))
 248                         break;
 249         }
 250         return np;
 251 }
 252 EXPORT_SYMBOL(v4l2_of_get_remote_port_parent);
 253
 254 /**
 255  * v4l2_of_get_remote_port() - get remote port node
 256  * @node: pointer to a local endpoint device_node
 257  *
 258  * Return: Remote port node associated with remote endpoint node linked
 259  *         to @node. Use of_node_put() on it when done.
 260  */
 261 struct device_node *v4l2_of_get_remote_port(const struct device_node *node)
 262 {
 263         struct device_node *np;
 264
 265         /* Get remote endpoint node. */
 266         np = of_parse_phandle(node, "remote-endpoint", 0);
 267         if (!np)
 268                 return NULL;
 269         return of_get_next_parent(np);
 270 }
 271 EXPORT_SYMBOL(v4l2_of_get_remote_port);