The fwnode_handle is a more generic way than OF device_node to describe
firmware nodes. Instead of the OF API, use more generic fwnode API to
obtain the same information.
As the V4L2 fwnode support will be required by a small minority of e.g.
ACPI based systems (the same might actually go for OF), make this a module
instead of embedding it in the videodev module.
The origins of the V4L2 fwnode framework is in the V4L2 OF framework.
Signed-off-by: Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx>
---
drivers/media/v4l2-core/Kconfig | 3 +
drivers/media/v4l2-core/Makefile | 1 +
drivers/media/v4l2-core/v4l2-fwnode.c | 345 ++++++++++++++++++++++++++++++++++
include/media/v4l2-fwnode.h | 104 ++++++++++
4 files changed, 453 insertions(+)
create mode 100644 drivers/media/v4l2-core/v4l2-fwnode.c
create mode 100644 include/media/v4l2-fwnode.h
diff --git a/drivers/media/v4l2-core/Kconfig b/drivers/media/v4l2-core/Kconfig
index 6b1b78f..a35c336 100644
--- a/drivers/media/v4l2-core/Kconfig
+++ b/drivers/media/v4l2-core/Kconfig
@@ -55,6 +55,9 @@ config V4L2_FLASH_LED_CLASS
When in doubt, say N.
+config V4L2_FWNODE
+ tristate
+
# Used by drivers that need Videobuf modules
config VIDEOBUF_GEN
tristate
diff --git a/drivers/media/v4l2-core/Makefile b/drivers/media/v4l2-core/Makefile
index 795a535..cf77a63 100644
--- a/drivers/media/v4l2-core/Makefile
+++ b/drivers/media/v4l2-core/Makefile
@@ -13,6 +13,7 @@ endif
ifeq ($(CONFIG_OF),y)
videodev-objs += v4l2-of.o
endif
+obj-$(CONFIG_V4L2_FWNODE) += v4l2-fwnode.o
ifeq ($(CONFIG_TRACEPOINTS),y)
videodev-objs += vb2-trace.o v4l2-trace.o
endif
diff --git a/drivers/media/v4l2-core/v4l2-fwnode.c b/drivers/media/v4l2-core/v4l2-fwnode.c
new file mode 100644
index 0000000..153c53c
--- /dev/null
+++ b/drivers/media/v4l2-core/v4l2-fwnode.c
@@ -0,0 +1,345 @@
+/*
+ * V4L2 fwnode binding parsing library
+ *
+ * The origins of the V4L2 fwnode library are in V4L2 OF library that
+ * formerly was located in v4l2-of.c.
+ *
+ * Copyright (c) 2016 Intel Corporation.
+ * Author: Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx>
+ *
+ * Copyright (C) 2012 - 2013 Samsung Electronics Co., Ltd.
+ * Author: Sylwester Nawrocki <s.nawrocki@xxxxxxxxxxx>
+ *
+ * Copyright (C) 2012 Renesas Electronics Corp.
+ * Author: Guennadi Liakhovetski <g.liakhovetski@xxxxxx>
+ *
+ * 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/acpi.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/property.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+#include <linux/types.h>
+
+#include <media/v4l2-fwnode.h>
+
+static int v4l2_fwnode_endpoint_parse_csi_bus(struct fwnode_handle *fwnode,
+ struct v4l2_fwnode_endpoint *vep)
+{
+ struct v4l2_fwnode_bus_mipi_csi2 *bus = &vep->bus.mipi_csi2;
+ bool have_clk_lane = false;
+ unsigned int flags = 0, lanes_used = 0;
+ unsigned int i;
+ u32 v;
+ int rval;
+
+ rval = fwnode_property_read_u32_array(fwnode, "data-lanes", NULL, 0);
+ if (rval > 0) {
+ u32 array[ARRAY_SIZE(bus->data_lanes)];
+
+ bus->num_data_lanes =
+ min_t(int, ARRAY_SIZE(bus->data_lanes), rval);
+
+ fwnode_property_read_u32_array(fwnode, "data-lanes", array,
+ bus->num_data_lanes);
+
+ for (i = 0; i < bus->num_data_lanes; i++) {
+ if (lanes_used & BIT(array[i]))
+ pr_warn("duplicated lane %u in data-lanes\n",
+ array[i]);
+ lanes_used |= BIT(array[i]);
+
+ bus->data_lanes[i] = array[i];
+ }
+ }
+
+ rval = fwnode_property_read_u32_array(fwnode, "lane-polarities", NULL,
+ 0);
+ if (rval > 0) {
+ u32 array[ARRAY_SIZE(bus->lane_polarities)];
+
+ if (rval < 1 + bus->num_data_lanes /* clock + data */) {
+ pr_warn("too few lane-polarities entries (need %u, got %u)\n",
+ 1 + bus->num_data_lanes, rval);
+ return -EINVAL;
+ }
+
+ fwnode_property_read_u32_array(fwnode, "lane-polarities", array,
+ 1 + bus->num_data_lanes);
+
+ for (i = 0; i < 1 + bus->num_data_lanes; i++)
+ bus->lane_polarities[i] = array[i];
+ }
+
+ if (!fwnode_property_read_u32(fwnode, "clock-lanes", &v)) {
+ if (lanes_used & BIT(v))
+ pr_warn("duplicated lane %u in clock-lanes\n", v);
+ lanes_used |= BIT(v);
+
+ bus->clock_lane = v;
+ have_clk_lane = true;
+ }
+
+ if (fwnode_property_present(fwnode, "clock-noncontinuous"))
+ 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;
+ vep->bus_type = V4L2_MBUS_CSI2;
+
+ return 0;
+}
+
+static void v4l2_fwnode_endpoint_parse_parallel_bus(
+ struct fwnode_handle *fwnode, struct v4l2_fwnode_endpoint *vep)
+{
+ struct v4l2_fwnode_bus_parallel *bus = &vep->bus.parallel;
+ unsigned int flags = 0;
+ u32 v;
+
+ if (!fwnode_property_read_u32(fwnode, "hsync-active", &v))
+ flags |= v ? V4L2_MBUS_HSYNC_ACTIVE_HIGH :
+ V4L2_MBUS_HSYNC_ACTIVE_LOW;
+
+ if (!fwnode_property_read_u32(fwnode, "vsync-active", &v))
+ flags |= v ? V4L2_MBUS_VSYNC_ACTIVE_HIGH :
+ V4L2_MBUS_VSYNC_ACTIVE_LOW;
+
+ if (!fwnode_property_read_u32(fwnode, "field-even-active", &v))
+ flags |= v ? V4L2_MBUS_FIELD_EVEN_HIGH :
+ V4L2_MBUS_FIELD_EVEN_LOW;
+ if (flags)
+ vep->bus_type = V4L2_MBUS_PARALLEL;
+ else
+ vep->bus_type = V4L2_MBUS_BT656;
+
+ if (!fwnode_property_read_u32(fwnode, "pclk-sample", &v))
+ flags |= v ? V4L2_MBUS_PCLK_SAMPLE_RISING :
+ V4L2_MBUS_PCLK_SAMPLE_FALLING;
+
+ if (!fwnode_property_read_u32(fwnode, "data-active", &v))
+ flags |= v ? V4L2_MBUS_DATA_ACTIVE_HIGH :
+ V4L2_MBUS_DATA_ACTIVE_LOW;
+
+ if (fwnode_property_present(fwnode, "slave-mode"))
+ flags |= V4L2_MBUS_SLAVE;
+ else
+ flags |= V4L2_MBUS_MASTER;
+
+ if (!fwnode_property_read_u32(fwnode, "bus-width", &v))
+ bus->bus_width = v;
+
+ if (!fwnode_property_read_u32(fwnode, "data-shift", &v))
+ bus->data_shift = v;
+
+ if (!fwnode_property_read_u32(fwnode, "sync-on-green-active", &v))
+ flags |= v ? V4L2_MBUS_VIDEO_SOG_ACTIVE_HIGH :
+ V4L2_MBUS_VIDEO_SOG_ACTIVE_LOW;
+
+ bus->flags = flags;
+
+}
+
+/**
+ * v4l2_fwnode_endpoint_parse() - parse all fwnode node properties
+ * @fwnode: pointer to the endpoint's fwnode handle
+ * @vep: pointer to the V4L2 fwnode 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 @fwnode.
+ *
+ * NOTE: This function does not parse properties the size of which is variable
+ * without a low fixed limit. Please use v4l2_fwnode_endpoint_alloc_parse() in
+ * new drivers instead.
+ *
+ * Return: 0 on success or a negative error code on failure.
+ */
+int v4l2_fwnode_endpoint_parse(struct fwnode_handle *fwnode,
+ struct v4l2_fwnode_endpoint *vep)
+{
+ int rval;
+
+ fwnode_graph_parse_endpoint(fwnode, &vep->base);
+
+ /* Zero fields from bus_type to until the end */
+ memset(&vep->bus_type, 0, sizeof(*vep) -
+ offsetof(typeof(*vep), bus_type));
+
+ rval = v4l2_fwnode_endpoint_parse_csi_bus(fwnode, vep);
+ if (rval)
+ return rval;
+ /*
+ * Parse the parallel video bus properties only if none
+ * of the MIPI CSI-2 specific properties were found.
+ */
+ if (vep->bus.mipi_csi2.flags == 0)
+ v4l2_fwnode_endpoint_parse_parallel_bus(fwnode, vep);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(v4l2_fwnode_endpoint_parse);
+
+/*
+ * v4l2_fwnode_endpoint_free() - free the V4L2 fwnode acquired by
+ * v4l2_fwnode_endpoint_alloc_parse()
+ * @vep - the V4L2 fwnode the resources of which are to be released
+ *
+ * It is safe to call this function with NULL argument or on a V4L2 fwnode the
+ * parsing of which failed.
+ */
+void v4l2_fwnode_endpoint_free(struct v4l2_fwnode_endpoint *vep)
+{
+ if (IS_ERR_OR_NULL(vep))
+ return;
+
+ kfree(vep->link_frequencies);
+ kfree(vep);
+}
+EXPORT_SYMBOL_GPL(v4l2_fwnode_endpoint_free);
+
+/**
+ * v4l2_fwnode_endpoint_alloc_parse() - parse all fwnode node properties
+ * @fwnode: pointer to the endpoint's fwnode handle
+ *
+ * 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 @fwnode.
+ *
+ * v4l2_fwnode_endpoint_alloc_parse() has two important differences to
+ * v4l2_fwnode_endpoint_parse():
+ *
+ * 1. It also parses variable size data.
+ *
+ * 2. The memory it has allocated to store the variable size data must be freed
+ * using v4l2_fwnode_endpoint_free() when no longer needed.
+ *
+ * Return: Pointer to v4l2_fwnode_endpoint if successful, on an error pointer
+ * on error.
+ */
+struct v4l2_fwnode_endpoint *v4l2_fwnode_endpoint_alloc_parse(
+ struct fwnode_handle *fwnode)
+{
+ struct v4l2_fwnode_endpoint *vep;
+ int rval;
+
+ vep = kzalloc(sizeof(*vep), GFP_KERNEL);
+ if (!vep)
+ return ERR_PTR(-ENOMEM);
+
+ rval = v4l2_fwnode_endpoint_parse(fwnode, vep);
+ if (rval < 0)
+ goto out_err;
+
+ rval = fwnode_property_read_u64_array(fwnode, "link-frequencies",
+ NULL, 0);
+ if (rval < 0)
+ goto out_err;
+
+ vep->link_frequencies =
+ kmalloc_array(rval, sizeof(*vep->link_frequencies), GFP_KERNEL);
+ if (!vep->link_frequencies) {
+ rval = -ENOMEM;
+ goto out_err;
+ }
+
+ vep->nr_of_link_frequencies = rval;
+
+ rval = fwnode_property_read_u64_array(fwnode, "link-frequencies",
+ vep->link_frequencies,
+ vep->nr_of_link_frequencies);
+ if (rval < 0)
+ goto out_err;
+
+ return vep;
+
+out_err:
+ v4l2_fwnode_endpoint_free(vep);
+ return ERR_PTR(rval);
+}
+EXPORT_SYMBOL_GPL(v4l2_fwnode_endpoint_alloc_parse);
+
+/**
+ * v4l2_fwnode_endpoint_parse_link() - parse a link between two endpoints
+ * @__fwnode: pointer to the endpoint's fwnode at the local end of the link
+ * @link: pointer to the V4L2 fwnode link data structure
+ *
+ * Fill the link structure with the local and remote nodes and port numbers.
+ * The local_node and remote_node fields are set to point to the local and
+ * remote port's parent nodes respectively (the port parent node being the
+ * parent node of the port node if that node isn't a 'ports' node, or the
+ * grand-parent node of the port node otherwise).
+ *
+ * A reference is taken to both the local and remote nodes, the caller must use
+ * v4l2_fwnode_endpoint_put_link() to drop the references when done with the
+ * link.
+ *
+ * Return: 0 on success, or -ENOLINK if the remote endpoint fwnode can't be
+ * found.
+ */
+int v4l2_fwnode_parse_link(struct fwnode_handle *__fwnode,
+ struct v4l2_fwnode_link *link)
+{
+ const char *port_prop = is_of_node(__fwnode) ? "reg" : "port";
+ struct fwnode_handle *fwnode;
+
+ memset(link, 0, sizeof(*link));
+
+ fwnode = fwnode_get_parent(__fwnode);
+ fwnode_property_read_u32(fwnode, port_prop, &link->local_port);
+ fwnode = fwnode_get_next_parent(fwnode);
+ if (is_of_node(fwnode) &&
+ of_node_cmp(to_of_node(fwnode)->name, "ports") == 0)
+ fwnode = fwnode_get_next_parent(fwnode);
+ link->local_node = fwnode;
+
+ fwnode = fwnode_graph_get_remote_endpoint(__fwnode);
+ if (!fwnode) {
+ fwnode_handle_put(fwnode);
+ return -ENOLINK;
+ }
+
+ fwnode = fwnode_get_parent(fwnode);
+ fwnode_property_read_u32(fwnode, port_prop, &link->remote_port);
+ fwnode = fwnode_get_next_parent(fwnode);
+ if (is_of_node(fwnode) &&
+ of_node_cmp(to_of_node(fwnode)->name, "ports") == 0)
+ fwnode = fwnode_get_next_parent(fwnode);
+ link->remote_node = fwnode;
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(v4l2_fwnode_parse_link);
+
+/**
+ * v4l2_fwnode_put_link() - drop references to nodes in a link
+ * @link: pointer to the V4L2 fwnode link data structure
+ *
+ * Drop references to the local and remote nodes in the link. This function
+ * must be called on every link parsed with v4l2_fwnode_parse_link().
+ */
+void v4l2_fwnode_put_link(struct v4l2_fwnode_link *link)
+{
+ fwnode_handle_put(link->local_node);
+ fwnode_handle_put(link->remote_node);
+}
+EXPORT_SYMBOL_GPL(v4l2_fwnode_put_link);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx>");
+MODULE_AUTHOR("Sylwester Nawrocki <s.nawrocki@xxxxxxxxxxx>");
+MODULE_AUTHOR("Guennadi Liakhovetski <g.liakhovetski@xxxxxx>");
diff --git a/include/media/v4l2-fwnode.h b/include/media/v4l2-fwnode.h
new file mode 100644
index 0000000..ecc1233
--- /dev/null
+++ b/include/media/v4l2-fwnode.h
@@ -0,0 +1,104 @@
+/*
+ * V4L2 fwnode binding parsing library
+ *
+ * Copyright (c) 2016 Intel Corporation.
+ * Author: Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx>
+ *
+ * Copyright (C) 2012 - 2013 Samsung Electronics Co., Ltd.
+ * Author: Sylwester Nawrocki <s.nawrocki@xxxxxxxxxxx>
+ *
+ * Copyright (C) 2012 Renesas Electronics Corp.
+ * Author: Guennadi Liakhovetski <g.liakhovetski@xxxxxx>
+ *
+ * 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_FWNODE_H
+#define _V4L2_FWNODE_H
+
+#include <linux/errno.h>
+#include <linux/fwnode.h>
+#include <linux/list.h>
+#include <linux/types.h>
+
+#include <media/v4l2-mediabus.h>
+
+struct fwnode_handle;
+
+/**
+ * struct v4l2_fwnode_bus_mipi_csi2 - MIPI CSI-2 bus data structure
+ * @flags: media bus (V4L2_MBUS_*) flags
+ * @data_lanes: an array of physical data lane indexes
+ * @clock_lane: physical lane index of the clock lane
+ * @num_data_lanes: number of data lanes
+ * @lane_polarities: polarity of the lanes. The order is the same of
+ * the physical lanes.
+ */
+struct v4l2_fwnode_bus_mipi_csi2 {
+ unsigned int flags;
+ unsigned char data_lanes[4];
+ unsigned char clock_lane;
+ unsigned short num_data_lanes;
+ bool lane_polarities[5];
+};
+
+/**
+ * struct v4l2_fwnode_bus_parallel - parallel data bus data structure
+ * @flags: media bus (V4L2_MBUS_*) flags
+ * @bus_width: bus width in bits
+ * @data_shift: data shift in bits
+ */
+struct v4l2_fwnode_bus_parallel {
+ unsigned int flags;
+ unsigned char bus_width;
+ unsigned char data_shift;
+};
+
+/**
+ * struct v4l2_fwnode_endpoint - the endpoint data structure
+ * @base: fwnode endpoint of the v4l2_fwnode
+ * @bus_type: bus type
+ * @bus: bus configuration data structure
+ * @link_frequencies: array of supported link frequencies
+ * @nr_of_link_frequencies: number of elements in link_frequenccies array
+ */
+struct v4l2_fwnode_endpoint {
+ struct fwnode_endpoint base;
+ /*
+ * Fields below this line will be zeroed by
+ * v4l2_fwnode_parse_endpoint()
+ */
+ enum v4l2_mbus_type bus_type;
+ union {
+ struct v4l2_fwnode_bus_parallel parallel;
+ struct v4l2_fwnode_bus_mipi_csi2 mipi_csi2;
+ } bus;
+ u64 *link_frequencies;
+ unsigned int nr_of_link_frequencies;
+};
+
+/**
+ * struct v4l2_fwnode_link - a link between two endpoints
+ * @local_node: pointer to device_node of this endpoint
+ * @local_port: identifier of the port this endpoint belongs to
+ * @remote_node: pointer to device_node of the remote endpoint
+ * @remote_port: identifier of the port the remote endpoint belongs to
+ */
+struct v4l2_fwnode_link {
+ struct fwnode_handle *local_node;
+ unsigned int local_port;
+ struct fwnode_handle *remote_node;
+ unsigned int remote_port;
+};
+
+int v4l2_fwnode_endpoint_parse(struct fwnode_handle *fwnode,
+ struct v4l2_fwnode_endpoint *vep);
+struct v4l2_fwnode_endpoint *v4l2_fwnode_endpoint_alloc_parse(
+ struct fwnode_handle *fwnode);
+void v4l2_fwnode_endpoint_free(struct v4l2_fwnode_endpoint *vep);
+int v4l2_fwnode_parse_link(struct fwnode_handle *fwnode,
+ struct v4l2_fwnode_link *link);
+void v4l2_fwnode_put_link(struct v4l2_fwnode_link *link);
+
+#endif /* _V4L2_FWNODE_H */
--
2.7.4
