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 void v4l2_of_parse_endpoint(const struct device_node *node,
 126                             struct v4l2_of_endpoint *endpoint)
 127 {
 128         struct device_node *port_node = of_get_parent(node);
 129
 130         memset(endpoint, 0, offsetof(struct v4l2_of_endpoint, head));
 131
 132         endpoint->local_node = node;
 133         /*
 134          * It doesn't matter whether the two calls below succeed.
 135          * If they don't then the default value 0 is used.
 136          */
 137         of_property_read_u32(port_node, "reg", &endpoint->port);
 138         of_property_read_u32(node, "reg", &endpoint->id);
 139
 140         v4l2_of_parse_csi_bus(node, endpoint);
 141         /*
 142          * Parse the parallel video bus properties only if none
 143          * of the MIPI CSI-2 specific properties were found.
 144          */
 145         if (endpoint->bus.mipi_csi2.flags == 0)
 146                 v4l2_of_parse_parallel_bus(node, endpoint);
 147
 148         of_node_put(port_node);
 149 }
 150 EXPORT_SYMBOL(v4l2_of_parse_endpoint);
 151
 152 /**
 153  * v4l2_of_get_next_endpoint() - get next endpoint node
 154  * @parent: pointer to the parent device node
 155  * @prev: previous endpoint node, or NULL to get first
 156  *
 157  * Return: An 'endpoint' node pointer with refcount incremented. Refcount
 158  * of the passed @prev node is not decremented, the caller have to use
 159  * of_node_put() on it when done.
 160  */
 161 struct device_node *v4l2_of_get_next_endpoint(const struct device_node *parent,
 162                                         struct device_node *prev)
 163 {
 164         struct device_node *endpoint;
 165         struct device_node *port = NULL;
 166
 167         if (!parent)
 168                 return NULL;
 169
 170         if (!prev) {
 171                 struct device_node *node;
 172                 /*
 173                  * It's the first call, we have to find a port subnode
 174                  * within this node or within an optional 'ports' node.
 175                  */
 176                 node = of_get_child_by_name(parent, "ports");
 177                 if (node)
 178                         parent = node;
 179
 180                 port = of_get_child_by_name(parent, "port");
 181
 182                 if (port) {
 183                         /* Found a port, get an endpoint. */
 184                         endpoint = of_get_next_child(port, NULL);
 185                         of_node_put(port);
 186                 } else {
 187                         endpoint = NULL;
 188                 }
 189
 190                 if (!endpoint)
 191                         pr_err("%s(): no endpoint nodes specified for %s\n",
 192                                __func__, parent->full_name);
 193                 of_node_put(node);
 194         } else {
 195                 port = of_get_parent(prev);
 196                 if (!port)
 197                         /* Hm, has someone given us the root node ?... */
 198                         return NULL;
 199
 200                 /* Avoid dropping prev node refcount to 0. */
 201                 of_node_get(prev);
 202                 endpoint = of_get_next_child(port, prev);
 203                 if (endpoint) {
 204                         of_node_put(port);
 205                         return endpoint;
 206                 }
 207
 208                 /* No more endpoints under this port, try the next one. */
 209                 do {
 210                         port = of_get_next_child(parent, port);
 211                         if (!port)
 212                                 return NULL;
 213                 } while (of_node_cmp(port->name, "port"));
 214
 215                 /* Pick up the first endpoint in this port. */
 216                 endpoint = of_get_next_child(port, NULL);
 217                 of_node_put(port);
 218         }
 219
 220         return endpoint;
 221 }
 222 EXPORT_SYMBOL(v4l2_of_get_next_endpoint);
 223
 224 /**
 225  * v4l2_of_get_remote_port_parent() - get remote port's parent node
 226  * @node: pointer to a local endpoint device_node
 227  *
 228  * Return: Remote device node associated with remote endpoint node linked
 229  *         to @node. Use of_node_put() on it when done.
 230  */
 231 struct device_node *v4l2_of_get_remote_port_parent(
 232                                const struct device_node *node)
 233 {
 234         struct device_node *np;
 235         unsigned int depth;
 236
 237         /* Get remote endpoint node. */
 238         np = of_parse_phandle(node, "remote-endpoint", 0);
 239
 240         /* Walk 3 levels up only if there is 'ports' node. */
 241         for (depth = 3; depth && np; depth--) {
 242                 np = of_get_next_parent(np);
 243                 if (depth == 2 && of_node_cmp(np->name, "ports"))
 244                         break;
 245         }
 246         return np;
 247 }
 248 EXPORT_SYMBOL(v4l2_of_get_remote_port_parent);
 249
 250 /**
 251  * v4l2_of_get_remote_port() - get remote port node
 252  * @node: pointer to a local endpoint device_node
 253  *
 254  * Return: Remote port node associated with remote endpoint node linked
 255  *         to @node. Use of_node_put() on it when done.
 256  */
 257 struct device_node *v4l2_of_get_remote_port(const struct device_node *node)
 258 {
 259         struct device_node *np;
 260
 261         /* Get remote endpoint node. */
 262         np = of_parse_phandle(node, "remote-endpoint", 0);
 263         if (!np)
 264                 return NULL;
 265         return of_get_parent(np);
 266 }
 267 EXPORT_SYMBOL(v4l2_of_get_remote_port);