From 4e7470ddca671aee2f5d11ba68573c94feddc5c2 Mon Sep 17 00:00:00 2001
From: Tomi Valkeinen <tomi.valkeinen@ti.com>
Date: Tue, 3 Dec 2013 16:57:40 +0200
Subject: [PATCH] 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 |   2 +-
 drivers/video/omap2/dss/dss-of.c | 159 +++++++++++++++++++++++++++++++++++++++
 include/video/omapdss.h          |  14 ++++
 3 files changed, 174 insertions(+), 1 deletion(-)
 create mode 100644 drivers/video/omap2/dss/dss-of.c

diff --git a/drivers/video/omap2/dss/Makefile b/drivers/video/omap2/dss/Makefile
index d3aa91bdd6a8..8aec8bda27cc 100644
--- a/drivers/video/omap2/dss/Makefile
+++ b/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
diff --git a/drivers/video/omap2/dss/dss-of.c b/drivers/video/omap2/dss/dss-of.c
new file mode 100644
index 000000000000..a4b20aaf6142
--- /dev/null
+++ b/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);
diff --git a/include/video/omapdss.h b/include/video/omapdss.h
index 3d7c51a6f9ff..e3cd2a921c2f 100644
--- a/include/video/omapdss.h
+++ b/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
-- 
2.11.0