OMAPDSS: add of helpers

Add helpers to get ports and endpoints from DT data.

These helpers parse v4l2 style ports and endpoints, but compared to the
v4l2 helpers, these allow iterating ports and endpoints separately.

This is a temporary solution until we get generic code to parse the
ports and endpoints.

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Reviewed-by: Archit Taneja <archit@ti.com>

drivers/video/omap2/dss/Makefile

@@ -1,7 +1,7 @@
 obj-$(CONFIG_OMAP2_DSS) += omapdss.o
 # Core DSS files
 omapdss-y := core.o dss.o dss_features.o dispc.o dispc_coefs.o display.o \
-	output.o
+	output.o dss-of.o
 # DSS compat layer files
 omapdss-y += manager.o manager-sysfs.o overlay.o overlay-sysfs.o apply.o \
 	dispc-compat.o display-sysfs.o

drivers/video/omap2/dss/dss-of.c

@@ -0,0 +1,159 @@
+/*
+ * Copyright (C) 2013 Texas Instruments
+ * Author: Tomi Valkeinen <tomi.valkeinen@ti.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published by
+ * the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ */
+
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/seq_file.h>
+
+#include <video/omapdss.h>
+
+struct device_node *
+omapdss_of_get_next_port(const struct device_node *parent,
+			 struct device_node *prev)
+{
+	struct device_node *port = NULL;
+
+	if (!parent)
+		return NULL;
+
+	if (!prev) {
+		struct device_node *ports;
+		/*
+		 * It's the first call, we have to find a port subnode
+		 * within this node or within an optional 'ports' node.
+		 */
+		ports = of_get_child_by_name(parent, "ports");
+		if (ports)
+			parent = ports;
+
+		port = of_get_child_by_name(parent, "port");
+
+		/* release the 'ports' node */
+		of_node_put(ports);
+	} else {
+		struct device_node *ports;
+
+		ports = of_get_parent(prev);
+		if (!ports)
+			return NULL;
+
+		do {
+			port = of_get_next_child(ports, prev);
+			if (!port) {
+				of_node_put(ports);
+				return NULL;
+			}
+			prev = port;
+		} while (of_node_cmp(port->name, "port") != 0);
+	}
+
+	return port;
+}
+EXPORT_SYMBOL_GPL(omapdss_of_get_next_port);
+
+struct device_node *
+omapdss_of_get_next_endpoint(const struct device_node *parent,
+			     struct device_node *prev)
+{
+	struct device_node *ep = NULL;
+
+	if (!parent)
+		return NULL;
+
+	do {
+		ep = of_get_next_child(parent, prev);
+		if (!ep)
+			return NULL;
+		prev = ep;
+	} while (of_node_cmp(ep->name, "endpoint") != 0);
+
+	return ep;
+}
+EXPORT_SYMBOL_GPL(omapdss_of_get_next_endpoint);
+
+static struct device_node *
+omapdss_of_get_remote_device_node(const struct device_node *node)
+{
+	struct device_node *np;
+	int i;
+
+	np = of_parse_phandle(node, "remote-endpoint", 0);
+
+	if (!np)
+		return NULL;
+
+	np = of_get_next_parent(np);
+
+	for (i = 0; i < 3 && np; ++i) {
+		struct property *prop;
+
+		prop = of_find_property(np, "compatible", NULL);
+
+		if (prop)
+			return np;
+
+		np = of_get_next_parent(np);
+	}
+
+	return NULL;
+}
+
+struct device_node *
+omapdss_of_get_first_endpoint(const struct device_node *parent)
+{
+	struct device_node *port, *ep;
+
+	port = omapdss_of_get_next_port(parent, NULL);
+
+	if (!port)
+		return NULL;
+
+	ep = omapdss_of_get_next_endpoint(port, NULL);
+
+	of_node_put(port);
+
+	return ep;
+}
+EXPORT_SYMBOL_GPL(omapdss_of_get_first_endpoint);
+
+struct omap_dss_device *
+omapdss_of_find_source_for_first_ep(struct device_node *node)
+{
+	struct device_node *ep;
+	struct device_node *src_node;
+	struct omap_dss_device *src;
+
+	ep = omapdss_of_get_first_endpoint(node);
+	if (!ep)
+		return ERR_PTR(-EINVAL);
+
+	src_node = omapdss_of_get_remote_device_node(ep);
+
+	of_node_put(ep);
+
+	if (!src_node)
+		return ERR_PTR(-EINVAL);
+
+	src = omap_dss_find_output_by_node(src_node);
+
+	of_node_put(src_node);
+
+	if (!src)
+		return ERR_PTR(-EPROBE_DEFER);
+
+	return src;
+}
+EXPORT_SYMBOL_GPL(omapdss_of_find_source_for_first_ep);

include/video/omapdss.h

@@ -1019,4 +1019,18 @@ static inline bool omapdss_device_is_enabled(struct omap_dss_device *dssdev)
 	return dssdev->state == OMAP_DSS_DISPLAY_ACTIVE;
 }
 
+struct device_node *
+omapdss_of_get_next_port(const struct device_node *parent,
+			 struct device_node *prev);
+
+struct device_node *
+omapdss_of_get_next_endpoint(const struct device_node *parent,
+			     struct device_node *prev);
+
+struct device_node *
+omapdss_of_get_first_endpoint(const struct device_node *parent);
+
+struct omap_dss_device *
+omapdss_of_find_source_for_first_ep(struct device_node *node);
+
 #endif