diff options
Diffstat (limited to 'drivers/media/v4l2-core/v4l2-of.c')
-rw-r--r-- | drivers/media/v4l2-core/v4l2-of.c | 266 |
1 files changed, 266 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 000000000000..aa59639d013c --- /dev/null +++ b/drivers/media/v4l2-core/v4l2-of.c @@ -0,0 +1,266 @@ +/* + * V4L2 OF binding parsing library + * + * Copyright (C) 2012 - 2013 Samsung Electronics Co., Ltd. + * Author: 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; + +} + +/** + * 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); |