[media] v4l: fwnode: Support generic fwnode for parsing standardised properties

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@linux.intel.com>
Tested-by: Hans Verkuil <hans.verkuil@cisco.com>
Tested-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

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

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

include/media/v4l2-fwnode.h

+/*
+ * V4L2 fwnode binding parsing library
+ *
+ * Copyright (c) 2016 Intel Corporation.
+ * Author: Sakari Ailus <sakari.ailus@linux.intel.com>
+ *
+ * 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.
+ */
+#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 */