From: Guennadi Liakhovetski <g.liakhovet...@gmx.de> Add a V4L2 OF parser, implementing bindings documented in Documentation/devicetree/bindings/media/video-interfaces.txt.
Signed-off-by: Guennadi Liakhovetski <g.liakhovet...@gmx.de> [s.nawro...@samsung.com: various corrections and improvements since the initial version] Signed-off-by: Sylwester Nawrocki <s.nawro...@samsung.com> --- Changes since v5: - renamed v4l2_of_parse_mipi_csi2_bus -> v4l2_of_parse_csi_bus, - corrected v4l2_of_get_remote_port_parent() function declaration for !CONFIG_OF, - reworked v4l2_of_get_next_endpoint() function to consider the 'port' nodes can be grouped under optional 'ports' node, - added kerneldoc description for v4l2_of_get_next_endpoint() function. This patch and the related bindings documentation can be browsed at: http://git.linuxtv.org/snawrocki/samsung.git/devicetree Changes since v4: - reworked v4l2_of_get_remote_port() function to consider cases where 'port' nodes are grouped in a parent 'ports' node, - rearranged struct v4l2_of_endpoint and related changes added in the parser code, - added kerneldoc description for struct v4l2_of_endpoint, - s/link/endpoint in the comments, --- drivers/media/v4l2-core/Makefile | 3 + drivers/media/v4l2-core/v4l2-of.c | 260 +++++++++++++++++++++++++++++++++++++ include/media/v4l2-of.h | 98 ++++++++++++++ 3 files changed, 361 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 a9d3552..00c4a19 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-$(CONFIG_VIDEO_DEV) += videodev.o obj-$(CONFIG_VIDEO_V4L2_INT_DEVICE) += v4l2-int-device.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..0bf1f75 --- /dev/null +++ b/drivers/media/v4l2-core/v4l2-of.c @@ -0,0 +1,260 @@ +/* + * V4L2 OF binding parsing library + * + * Copyright (C) 2012 Renesas Electronics Corp. + * Author: Guennadi Liakhovetski <g.liakhovet...@gmx.de> + * + * Copyright (C) 2012 - 2013 Samsung Electronics Co., Ltd. + * Sylwester Nawrocki <s.nawro...@samsung.com> + * + * 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_csi_bus() - 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_csi_bus(const struct device_node *node, + struct v4l2_of_endpoint *endpoint) +{ + struct v4l2_mbus_mipi_csi2 *mipi_csi2 = &endpoint->mbus.mipi_csi2; + 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_csi_bus); + +/** + * 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->mbus.parallel.bus_width = v; + + if (!of_property_read_u32(node, "data-shift", &v)) + endpoint->mbus.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); + struct v4l2_of_mbus *mbus = &endpoint->mbus; + bool data_lanes_present = false; + + memset(endpoint, 0, sizeof(*endpoint)); + + 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_parallel_bus(node, endpoint); + + /* If any parallel bus properties have been found, skip serial ones. */ + if (mbus->parallel.bus_width || mbus->parallel.data_shift || + mbus->flags) { + /* Default parallel bus-master. */ + if (!(mbus->flags & V4L2_MBUS_SLAVE)) + mbus->flags |= V4L2_MBUS_MASTER; + return; + } + + mbus->type = V4L2_MBUS_CSI2; + + if (!v4l2_of_parse_csi_bus(node, endpoint)) + data_lanes_present = true; + + if ((mbus->mipi_csi2.clock_lane || data_lanes_present) && + !(mbus->flags & V4L2_MBUS_CSI2_NONCONTINUOUS_CLOCK)) { + /* Default CSI-2: continuous clock. */ + mbus->flags |= V4L2_MBUS_CSI2_CONTINUOUS_CLOCK; + } +} +EXPORT_SYMBOL(v4l2_of_parse_endpoint); + +/** + * v4l2_of_get_next_endpoint() - get next endpoint node + * @parent: pointer to the parent's 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, *port = NULL; + + if (!parent) + return NULL; + + if (!prev) { + /* + * It's the first call, we have to find a port subnode + * within this node or within an optional 'ports' node. + */ + while ((port = of_get_next_child(parent, port))) { + if (!of_node_cmp(port->name, "port")) + break; + if (!of_node_cmp(port->name, "ports")) { + parent = port; + of_node_put(port); + port = NULL; + } + }; + 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 lv = 3; + + /* Get remote endpoint node. */ + np = of_parse_phandle(node, "remote-endpoint", 0); + + /* Walk 3 levels up only if there is 'ports' node. */ + while (np && lv && (lv != 1 || !of_node_cmp(np->name, "ports"))) { + lv--; + np = of_get_next_parent(np); + } + return np; +} +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..458e97b --- /dev/null +++ b/include/media/v4l2-of.h @@ -0,0 +1,98 @@ +/* + * V4L2 OF binding parsing library + * + * Copyright (C) 2012 Renesas Electronics Corp. + * Author: Guennadi Liakhovetski <g.liakhovet...@gmx.de> + * + * Copyright (C) 2012 - 2013 Samsung Electronics Co., Ltd. + * Sylwester Nawrocki <s.nawro...@samsung.com> + * + * 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_mbus_mipi_csi2 { + unsigned char data_lanes[4]; + unsigned char clock_lane; + unsigned short num_data_lanes; +}; + +struct v4l2_mbus_parallel { + unsigned char bus_width; + unsigned char data_shift; +}; + +/** + * struct v4l2_of_endpoint - the endpoint data structure + * @port: identifier (value of reg property) of a port this endpoint belongs to + * @id: identifier (value of reg property) of this endpoint + * @head: list head for this structure + * @local_node: pointer to device_node of this endpoint + * @remote: phandle to remote endpoint node + * @type: media bus type + * @flags: media bus (V4L2_MBUS_*) flags + * @mipi_csi2: MIPI CSI-2 bus configuration data structure + * @parallel: parallel bus configuration data structure + */ +struct v4l2_of_endpoint { + unsigned int port; + unsigned int id; + struct list_head head; + const struct device_node *local_node; + const __be32 *remote; + struct v4l2_of_mbus { + enum v4l2_mbus_type type; + unsigned int flags; + union { + struct v4l2_mbus_mipi_csi2 mipi_csi2; + struct v4l2_mbus_parallel parallel; + }; + } mbus; +}; + +#ifdef CONFIG_OF +int v4l2_of_parse_csi_bus(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_port_parent( + const struct device_node *node) +{ + return NULL; +} + +#endif /* CONFIG_OF */ + +#endif /* _V4L2_OF_H */ -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
