[PATCH RFC v3 02/15] [media] Add a V4L2 OF parser
Sylwester Nawrocki
s.nawrocki at samsung.com
Fri Jan 4 04:09:22 EST 2013
From: Guennadi Liakhovetski <g.liakhovetski at gmx.de>
Add a V4L2 OF parser, implementing bindings documented in
Documentation/devicetree/bindings/media/video-interfaces.txt.
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski at gmx.de>
Signed-off-by: Sylwester Nawrocki <s.nawrocki at samsung.com>
---
Changes since v2:
- added missing EXPORT_SYMBOL for v4l2_of_parse_mipi_csi2()
and v4l2_of_parse_parallel_bus() functions,
- include string.h header instead of slab.h.
drivers/media/v4l2-core/Makefile | 3 +
drivers/media/v4l2-core/v4l2-of.c | 251 +++++++++++++++++++++++++++++++++++++
include/media/v4l2-of.h | 79 ++++++++++++
3 files changed, 333 insertions(+)
create mode 100644 drivers/media/v4l2-core/v4l2-of.c
create mode 100644 include/media/v4l2-of.h
diff --git a/drivers/media/v4l2-core/Makefile b/drivers/media/v4l2-core/Makefile
index c2d61d4..00f64d6 100644
--- a/drivers/media/v4l2-core/Makefile
+++ b/drivers/media/v4l2-core/Makefile
@@ -9,6 +9,9 @@ videodev-objs := v4l2-dev.o v4l2-ioctl.o v4l2-device.o v4l2-fh.o \
ifeq ($(CONFIG_COMPAT),y)
videodev-objs += v4l2-compat-ioctl32.o
endif
+ifeq ($(CONFIG_OF),y)
+ videodev-objs += v4l2-of.o
+endif
obj-$(CONFIG_VIDEO_DEV) += videodev.o v4l2-int-device.o
obj-$(CONFIG_VIDEO_V4L2) += v4l2-common.o
diff --git a/drivers/media/v4l2-core/v4l2-of.c b/drivers/media/v4l2-core/v4l2-of.c
new file mode 100644
index 0000000..483245c
--- /dev/null
+++ b/drivers/media/v4l2-core/v4l2-of.c
@@ -0,0 +1,251 @@
+/*
+ * V4L2 OF binding parsing library
+ *
+ * Copyright (C) 2012 Renesas Electronics Corp.
+ * Author: Guennadi Liakhovetski <g.liakhovetski at 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>
+
+/**
+ * v4l2_of_parse_mipi_csi2() - parse MIPI CSI-2 bus properties
+ * @node: pointer to endpoint device_node
+ * @endpoint: pointer to v4l2_of_endpoint data structure
+ *
+ * Return: 0 on success or negative error value otherwise.
+ */
+int v4l2_of_parse_mipi_csi2(const struct device_node *node,
+ struct v4l2_of_endpoint *endpoint)
+{
+ struct v4l2_of_mipi_csi2 *mipi_csi2 = &endpoint->mipi_csi_2;
+ u32 data_lanes[ARRAY_SIZE(mipi_csi2->data_lanes)];
+ struct property *prop;
+ const __be32 *lane = NULL;
+ u32 v;
+ int i = 0;
+
+ prop = of_find_property(node, "data-lanes", NULL);
+ if (!prop)
+ return -EINVAL;
+ do {
+ lane = of_prop_next_u32(prop, lane, &data_lanes[i]);
+ } while (lane && i++ < ARRAY_SIZE(data_lanes));
+
+ mipi_csi2->num_data_lanes = i;
+ while (i--)
+ mipi_csi2->data_lanes[i] = data_lanes[i];
+
+ if (!of_property_read_u32(node, "clock-lanes", &v))
+ mipi_csi2->clock_lane = v;
+
+ if (of_get_property(node, "clock-noncontinuous", &v))
+ endpoint->mbus_flags |= V4L2_MBUS_CSI2_NONCONTINUOUS_CLOCK;
+
+ return 0;
+}
+EXPORT_SYMBOL(v4l2_of_parse_mipi_csi2);
+
+/**
+ * v4l2_of_parse_parallel_bus() - parse parallel bus properties
+ * @node: pointer to endpoint device_node
+ * @endpoint: pointer to v4l2_of_endpoint data structure
+ */
+void v4l2_of_parse_parallel_bus(const struct device_node *node,
+ struct v4l2_of_endpoint *endpoint)
+{
+ unsigned int flags = 0;
+ u32 v;
+
+ if (WARN_ON(!endpoint))
+ return;
+
+ 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->mbus_type = V4L2_MBUS_PARALLEL;
+ else
+ endpoint->mbus_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;
+
+ if (!of_property_read_u32(node, "bus-width", &v))
+ endpoint->parallel.bus_width = v;
+
+ if (!of_property_read_u32(node, "data-shift", &v))
+ endpoint->parallel.data_shift = v;
+
+ endpoint->mbus_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 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)
+{
+ const struct device_node *port_node = of_get_parent(node);
+ bool data_lanes_present = false;
+
+ memset(endpoint, 0, sizeof(*endpoint));
+
+ endpoint->local_node = node;
+
+ /* Doesn't matter, whether the below two calls succeed */
+ of_property_read_u32(port_node, "reg", &endpoint->port);
+ of_property_read_u32(node, "reg", &endpoint->addr);
+
+ v4l2_of_parse_parallel_bus(node, endpoint);
+
+ /* If any parallel bus properties have been found, skip serial ones */
+ if (endpoint->parallel.bus_width || endpoint->parallel.data_shift ||
+ endpoint->mbus_flags) {
+ /* Default parallel bus-master */
+ if (!(endpoint->mbus_flags & V4L2_MBUS_SLAVE))
+ endpoint->mbus_flags |= V4L2_MBUS_MASTER;
+ return;
+ }
+
+ endpoint->mbus_type = V4L2_MBUS_CSI2;
+
+ if (!v4l2_of_parse_mipi_csi2(node, endpoint))
+ data_lanes_present = true;
+
+ if ((endpoint->mipi_csi_2.clock_lane || data_lanes_present) &&
+ !(endpoint->mbus_flags & V4L2_MBUS_CSI2_NONCONTINUOUS_CLOCK)) {
+ /* Default CSI-2: continuous clock */
+ endpoint->mbus_flags |= V4L2_MBUS_CSI2_CONTINUOUS_CLOCK;
+ }
+}
+EXPORT_SYMBOL(v4l2_of_parse_endpoint);
+
+/*
+ * Return a refcounted next "endpoint" DT node. Contrary to the common OF
+ * practice, we do not drop the reference to previous, users have to do it
+ * themselves, when they're done with the node.
+ */
+struct device_node *v4l2_of_get_next_endpoint(const struct device_node *parent,
+ struct device_node *previous)
+{
+ struct device_node *child, *port;
+
+ if (!parent)
+ return NULL;
+
+ if (!previous) {
+ /*
+ * If this is the first call, we have to find a port within this
+ * node
+ */
+ for_each_child_of_node(parent, port) {
+ if (!of_node_cmp(port->name, "port"))
+ break;
+ }
+ if (port) {
+ /* Found a port, get a link */
+ child = of_get_next_child(port, NULL);
+ of_node_put(port);
+ } else {
+ child = NULL;
+ }
+ if (!child)
+ pr_err("%s(): Invalid DT: %s has no link children!\n",
+ __func__, parent->name);
+ } else {
+ port = of_get_parent(previous);
+ if (!port)
+ /* Hm, has someone given us the root node?... */
+ return NULL;
+
+ /* Avoid dropping previous refcount to 0 */
+ of_node_get(previous);
+ child = of_get_next_child(port, previous);
+ if (child) {
+ of_node_put(port);
+ return child;
+ }
+
+ /* No more links 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 link on this port */
+ child = of_get_next_child(port, NULL);
+ of_node_put(port);
+ }
+
+ return child;
+}
+EXPORT_SYMBOL(v4l2_of_get_next_endpoint);
+
+/**
+ * v4l2_of_get_remote_port_parent() - get remote port's parent node
+ * @node: pointer to 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 *re, *tmp;
+
+ /* Get remote endpoint DT node. */
+ re = of_parse_phandle(node, "remote-endpoint", 0);
+ if (!re)
+ return NULL;
+
+ /* Remote port. */
+ tmp = of_get_parent(re);
+ of_node_put(re);
+ if (!tmp)
+ return NULL;
+
+ /* Remote device node. */
+ re = of_get_parent(tmp);
+ of_node_put(tmp);
+
+ return re;
+}
+EXPORT_SYMBOL(v4l2_of_get_remote_port_parent);
diff --git a/include/media/v4l2-of.h b/include/media/v4l2-of.h
new file mode 100644
index 0000000..1aba3b3
--- /dev/null
+++ b/include/media/v4l2-of.h
@@ -0,0 +1,79 @@
+/*
+ * V4L2 OF binding parsing library
+ *
+ * Copyright (C) 2012 Renesas Electronics Corp.
+ * Author: Guennadi Liakhovetski <g.liakhovetski at 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.
+ */
+#ifndef _V4L2_OF_H
+#define _V4L2_OF_H
+
+#include <linux/list.h>
+#include <linux/types.h>
+#include <linux/errno.h>
+
+#include <media/v4l2-mediabus.h>
+
+struct device_node;
+
+struct v4l2_of_mipi_csi2 {
+ unsigned char data_lanes[4];
+ unsigned char clock_lane;
+ unsigned short num_data_lanes;
+};
+
+struct v4l2_of_endpoint {
+ unsigned int port;
+ unsigned int addr;
+ struct list_head head;
+ const struct device_node *local_node;
+ const __be32 *remote;
+ enum v4l2_mbus_type mbus_type;
+ unsigned int mbus_flags;
+ union {
+ struct {
+ unsigned char bus_width;
+ unsigned char data_shift;
+ } parallel;
+ struct v4l2_of_mipi_csi2 mipi_csi_2;
+ };
+};
+
+#ifdef CONFIG_OF
+int v4l2_of_parse_mipi_csi2(const struct device_node *node,
+ struct v4l2_of_endpoint *endpoint);
+void v4l2_of_parse_parallel_bus(const struct device_node *node,
+ struct v4l2_of_endpoint *endpoint);
+void v4l2_of_parse_endpoint(const struct device_node *node,
+ struct v4l2_of_endpoint *link);
+struct device_node *v4l2_of_get_next_endpoint(const struct device_node *parent,
+ struct device_node *previous);
+struct device_node *v4l2_of_get_remote_port_parent(
+ const struct device_node *node);
+#else /* CONFIG_OF */
+
+static inline int v4l2_of_parse_endpoint(const struct device_node *node,
+ struct v4l2_of_endpoint *link)
+{
+ return -ENOSYS;
+}
+
+static inline struct device_node *v4l2_of_get_next_endpoint(
+ const struct device_node *parent,
+ struct device_node *previous)
+{
+ return NULL;
+}
+
+static inline struct device_node *v4l2_of_get_remote_endpoint(
+ const struct device_node *node)
+{
+ return NULL;
+}
+
+#endif /* CONFIG_OF */
+
+#endif /* _V4L2_OF_H */
--
1.7.9.5
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