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authorGuennadi Liakhovetski <g.liakhovetski@gmx.de>2012-09-26 05:24:03 -0300
committerMauro Carvalho Chehab <mchehab@redhat.com>2013-03-31 10:34:09 -0300
commit99fd133f907afdb430942d8d2ae53faa438adfe8 (patch)
treee26faf4e708531d713aee69a0b3355324a9ba046 /drivers/media/v4l2-core/v4l2-of.c
parent53c5b6c95f1850b0f95b445e0c6f1c133b00bfef (diff)
[media] Add a V4L2 OF parser
Add a V4L2 OF parser, implementing bindings documented in Documentation/devicetree/bindings/media/video-interfaces.txt. [s.nawrocki@samsung.com: various corrections and improvements since the initial version] Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de> Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com> Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Diffstat (limited to 'drivers/media/v4l2-core/v4l2-of.c')
-rw-r--r--drivers/media/v4l2-core/v4l2-of.c267
1 files changed, 267 insertions, 0 deletions
diff --git a/drivers/media/v4l2-core/v4l2-of.c b/drivers/media/v4l2-core/v4l2-of.c
new file mode 100644
index 0000000..e38e210
--- /dev/null
+++ b/drivers/media/v4l2-core/v4l2-of.c
@@ -0,0 +1,267 @@
+/*
+ * V4L2 OF binding parsing library
+ *
+ * Copyright (C) 2012 - 2013 Samsung Electronics Co., Ltd.
+ * Sylwester Nawrocki <s.nawrocki@samsung.com>
+ *
+ * Copyright (C) 2012 Renesas Electronics Corp.
+ * Author: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of version 2 of the GNU General Public License as
+ * published by the Free Software Foundation.
+ */
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/string.h>
+#include <linux/types.h>
+
+#include <media/v4l2-of.h>
+
+static void v4l2_of_parse_csi_bus(const struct device_node *node,
+ struct v4l2_of_endpoint *endpoint)
+{
+ struct v4l2_of_bus_mipi_csi2 *bus = &endpoint->bus.mipi_csi2;
+ u32 data_lanes[ARRAY_SIZE(bus->data_lanes)];
+ struct property *prop;
+ bool have_clk_lane = false;
+ unsigned int flags = 0;
+ u32 v;
+
+ prop = of_find_property(node, "data-lanes", NULL);
+ if (prop) {
+ const __be32 *lane = NULL;
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(data_lanes); i++) {
+ lane = of_prop_next_u32(prop, lane, &data_lanes[i]);
+ if (!lane)
+ break;
+ }
+ bus->num_data_lanes = i;
+ while (i--)
+ bus->data_lanes[i] = data_lanes[i];
+ }
+
+ if (!of_property_read_u32(node, "clock-lanes", &v)) {
+ bus->clock_lane = v;
+ have_clk_lane = true;
+ }
+
+ if (of_get_property(node, "clock-noncontinuous", &v))
+ flags |= V4L2_MBUS_CSI2_NONCONTINUOUS_CLOCK;
+ else if (have_clk_lane || bus->num_data_lanes > 0)
+ flags |= V4L2_MBUS_CSI2_CONTINUOUS_CLOCK;
+
+ bus->flags = flags;
+ endpoint->bus_type = V4L2_MBUS_CSI2;
+}
+
+static void v4l2_of_parse_parallel_bus(const struct device_node *node,
+ struct v4l2_of_endpoint *endpoint)
+{
+ struct v4l2_of_bus_parallel *bus = &endpoint->bus.parallel;
+ unsigned int flags = 0;
+ u32 v;
+
+ if (!of_property_read_u32(node, "hsync-active", &v))
+ flags |= v ? V4L2_MBUS_HSYNC_ACTIVE_HIGH :
+ V4L2_MBUS_HSYNC_ACTIVE_LOW;
+
+ if (!of_property_read_u32(node, "vsync-active", &v))
+ flags |= v ? V4L2_MBUS_VSYNC_ACTIVE_HIGH :
+ V4L2_MBUS_VSYNC_ACTIVE_LOW;
+
+ if (!of_property_read_u32(node, "pclk-sample", &v))
+ flags |= v ? V4L2_MBUS_PCLK_SAMPLE_RISING :
+ V4L2_MBUS_PCLK_SAMPLE_FALLING;
+
+ if (!of_property_read_u32(node, "field-even-active", &v))
+ flags |= v ? V4L2_MBUS_FIELD_EVEN_HIGH :
+ V4L2_MBUS_FIELD_EVEN_LOW;
+ if (flags)
+ endpoint->bus_type = V4L2_MBUS_PARALLEL;
+ else
+ endpoint->bus_type = V4L2_MBUS_BT656;
+
+ if (!of_property_read_u32(node, "data-active", &v))
+ flags |= v ? V4L2_MBUS_DATA_ACTIVE_HIGH :
+ V4L2_MBUS_DATA_ACTIVE_LOW;
+
+ if (of_get_property(node, "slave-mode", &v))
+ flags |= V4L2_MBUS_SLAVE;
+ else
+ flags |= V4L2_MBUS_MASTER;
+
+ if (!of_property_read_u32(node, "bus-width", &v))
+ bus->bus_width = v;
+
+ if (!of_property_read_u32(node, "data-shift", &v))
+ bus->data_shift = v;
+
+ bus->flags = flags;
+
+}
+EXPORT_SYMBOL(v4l2_of_parse_parallel_bus);
+
+/**
+ * v4l2_of_parse_endpoint() - parse all endpoint node properties
+ * @node: pointer to endpoint device_node
+ * @endpoint: pointer to the V4L2 OF endpoint data structure
+ *
+ * All properties are optional. If none are found, we don't set any flags.
+ * This means the port has a static configuration and no properties have
+ * to be specified explicitly.
+ * If any properties that identify the bus as parallel are found and
+ * slave-mode isn't set, we set V4L2_MBUS_MASTER. Similarly, if we recognise
+ * the bus as serial CSI-2 and clock-noncontinuous isn't set, we set the
+ * V4L2_MBUS_CSI2_CONTINUOUS_CLOCK flag.
+ * The caller should hold a reference to @node.
+ */
+void v4l2_of_parse_endpoint(const struct device_node *node,
+ struct v4l2_of_endpoint *endpoint)
+{
+ struct device_node *port_node = of_get_parent(node);
+
+ memset(endpoint, 0, offsetof(struct v4l2_of_endpoint, head));
+
+ endpoint->local_node = node;
+ /*
+ * It doesn't matter whether the two calls below succeed.
+ * If they don't then the default value 0 is used.
+ */
+ of_property_read_u32(port_node, "reg", &endpoint->port);
+ of_property_read_u32(node, "reg", &endpoint->id);
+
+ v4l2_of_parse_csi_bus(node, endpoint);
+ /*
+ * Parse the parallel video bus properties only if none
+ * of the MIPI CSI-2 specific properties were found.
+ */
+ if (endpoint->bus.mipi_csi2.flags == 0)
+ v4l2_of_parse_parallel_bus(node, endpoint);
+
+ of_node_put(port_node);
+}
+EXPORT_SYMBOL(v4l2_of_parse_endpoint);
+
+/**
+ * v4l2_of_get_next_endpoint() - get next endpoint node
+ * @parent: pointer to the parent device node
+ * @prev: previous endpoint node, or NULL to get first
+ *
+ * Return: An 'endpoint' node pointer with refcount incremented. Refcount
+ * of the passed @prev node is not decremented, the caller have to use
+ * of_node_put() on it when done.
+ */
+struct device_node *v4l2_of_get_next_endpoint(const struct device_node *parent,
+ struct device_node *prev)
+{
+ struct device_node *endpoint;
+ struct device_node *port = NULL;
+
+ if (!parent)
+ return NULL;
+
+ if (!prev) {
+ struct device_node *node;
+ /*
+ * It's the first call, we have to find a port subnode
+ * within this node or within an optional 'ports' node.
+ */
+ node = of_get_child_by_name(parent, "ports");
+ if (node)
+ parent = node;
+
+ for_each_child_of_node(parent, node) {
+ if (!of_node_cmp(node->name, "port")) {
+ port = node;
+ break;
+ }
+ }
+ if (port) {
+ /* Found a port, get an endpoint. */
+ endpoint = of_get_next_child(port, NULL);
+ of_node_put(port);
+ } else {
+ endpoint = NULL;
+ }
+
+ if (!endpoint)
+ pr_err("%s(): no endpoint nodes specified for %s\n",
+ __func__, parent->full_name);
+ } else {
+ port = of_get_parent(prev);
+ if (!port)
+ /* Hm, has someone given us the root node ?... */
+ return NULL;
+
+ /* Avoid dropping prev node refcount to 0. */
+ of_node_get(prev);
+ endpoint = of_get_next_child(port, prev);
+ if (endpoint) {
+ of_node_put(port);
+ return endpoint;
+ }
+
+ /* No more endpoints under this port, try the next one. */
+ do {
+ port = of_get_next_child(parent, port);
+ if (!port)
+ return NULL;
+ } while (of_node_cmp(port->name, "port"));
+
+ /* Pick up the first endpoint in this port. */
+ endpoint = of_get_next_child(port, NULL);
+ of_node_put(port);
+ }
+
+ return endpoint;
+}
+EXPORT_SYMBOL(v4l2_of_get_next_endpoint);
+
+/**
+ * v4l2_of_get_remote_port_parent() - get remote port's parent node
+ * @node: pointer to a local endpoint device_node
+ *
+ * Return: Remote device node associated with remote endpoint node linked
+ * to @node. Use of_node_put() on it when done.
+ */
+struct device_node *v4l2_of_get_remote_port_parent(
+ const struct device_node *node)
+{
+ struct device_node *np;
+ unsigned int depth;
+
+ /* Get remote endpoint node. */
+ np = of_parse_phandle(node, "remote-endpoint", 0);
+
+ /* Walk 3 levels up only if there is 'ports' node. */
+ for (depth = 3; depth && np; depth--) {
+ np = of_get_next_parent(np);
+ if (depth == 2 && of_node_cmp(np->name, "ports"))
+ break;
+ }
+ return np;
+}
+EXPORT_SYMBOL(v4l2_of_get_remote_port_parent);
+
+/**
+ * v4l2_of_get_remote_port() - get remote port node
+ * @node: pointer to a local endpoint device_node
+ *
+ * Return: Remote port node associated with remote endpoint node linked
+ * to @node. Use of_node_put() on it when done.
+ */
+struct device_node *v4l2_of_get_remote_port(const struct device_node *node)
+{
+ struct device_node *np;
+
+ /* Get remote endpoint node. */
+ np = of_parse_phandle(node, "remote-endpoint", 0);
+ if (!np)
+ return NULL;
+ return of_get_parent(np);
+}
+EXPORT_SYMBOL(v4l2_of_get_remote_port);