drivers: core: ofnode: Add panel timing decode.

ofnode_decode_display_timing supports reading timing parameters from
subnode of display-timings node, for displays supporting multiple
resolution, in case if a display supports single resolution, it fails
reading directly from display-timings node, to support it
ofnode_decode_panel_timing is added.

Signed-off-by: Nikhil M Jain <n-jain1@ti.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/core/ofnode.c b/drivers/core/ofnode.c
index 4d56b1a..d08578e 100644
--- a/drivers/core/ofnode.c
+++ b/drivers/core/ofnode.c
@@ -991,6 +991,53 @@
 	return ret;
 }
 
+int ofnode_decode_panel_timing(ofnode parent,
+			       struct display_timing *dt)
+{
+	ofnode timings;
+	u32 val = 0;
+	int ret = 0;
+
+	timings = ofnode_find_subnode(parent, "panel-timings");
+	if (!ofnode_valid(timings))
+		return -EINVAL;
+	memset(dt, 0, sizeof(*dt));
+	ret |= decode_timing_property(timings, "hback-porch", &dt->hback_porch);
+	ret |= decode_timing_property(timings, "hfront-porch", &dt->hfront_porch);
+	ret |= decode_timing_property(timings, "hactive", &dt->hactive);
+	ret |= decode_timing_property(timings, "hsync-len", &dt->hsync_len);
+	ret |= decode_timing_property(timings, "vback-porch", &dt->vback_porch);
+	ret |= decode_timing_property(timings, "vfront-porch", &dt->vfront_porch);
+	ret |= decode_timing_property(timings, "vactive", &dt->vactive);
+	ret |= decode_timing_property(timings, "vsync-len", &dt->vsync_len);
+	ret |= decode_timing_property(timings, "clock-frequency", &dt->pixelclock);
+	dt->flags = 0;
+	if (!ofnode_read_u32(timings, "vsync-active", &val)) {
+		dt->flags |= val ? DISPLAY_FLAGS_VSYNC_HIGH :
+		    DISPLAY_FLAGS_VSYNC_LOW;
+	}
+	if (!ofnode_read_u32(timings, "hsync-active", &val)) {
+		dt->flags |= val ? DISPLAY_FLAGS_HSYNC_HIGH :
+		    DISPLAY_FLAGS_HSYNC_LOW;
+	}
+	if (!ofnode_read_u32(timings, "de-active", &val)) {
+		dt->flags |= val ? DISPLAY_FLAGS_DE_HIGH :
+		    DISPLAY_FLAGS_DE_LOW;
+	}
+	if (!ofnode_read_u32(timings, "pixelclk-active", &val)) {
+		dt->flags |= val ? DISPLAY_FLAGS_PIXDATA_POSEDGE :
+		DISPLAY_FLAGS_PIXDATA_NEGEDGE;
+	}
+	if (ofnode_read_bool(timings, "interlaced"))
+		dt->flags |= DISPLAY_FLAGS_INTERLACED;
+	if (ofnode_read_bool(timings, "doublescan"))
+		dt->flags |= DISPLAY_FLAGS_DOUBLESCAN;
+	if (ofnode_read_bool(timings, "doubleclk"))
+		dt->flags |= DISPLAY_FLAGS_DOUBLECLK;
+
+	return ret;
+}
+
 const void *ofnode_get_property(ofnode node, const char *propname, int *lenp)
 {
 	if (ofnode_is_np(node))
diff --git a/drivers/core/read.c b/drivers/core/read.c
index 3e5fea8..e0543bb 100644
--- a/drivers/core/read.c
+++ b/drivers/core/read.c
@@ -420,6 +420,12 @@
 	return ofnode_decode_display_timing(dev_ofnode(dev), index, config);
 }
 
+int dev_decode_panel_timing(const struct udevice *dev,
+			    struct display_timing *config)
+{
+	return ofnode_decode_panel_timing(dev_ofnode(dev), config);
+}
+
 ofnode dev_get_phy_node(const struct udevice *dev)
 {
 	return ofnode_get_phy_node(dev_ofnode(dev));
diff --git a/include/dm/ofnode.h b/include/dm/ofnode.h
index fa98656..3f6b084 100644
--- a/include/dm/ofnode.h
+++ b/include/dm/ofnode.h
@@ -975,6 +975,18 @@
 				 struct display_timing *config);
 
 /**
+ * ofnode_decode_panel_timing() - decode display timings
+ *
+ * Decode panel timings from the supplied 'panel-timings' node.
+ *
+ * @node:	'display-timing' node containing the timing subnodes
+ * @config:	Place to put timings
+ * Return: 0 if OK, -FDT_ERR_NOTFOUND if not found
+ */
+int ofnode_decode_panel_timing(ofnode node,
+			       struct display_timing *config);
+
+/**
  * ofnode_get_property() - get a pointer to the value of a node property
  *
  * @node: node to read
diff --git a/include/dm/read.h b/include/dm/read.h
index cc4f161..56ac076 100644
--- a/include/dm/read.h
+++ b/include/dm/read.h
@@ -785,6 +785,20 @@
 			      struct display_timing *config);
 
 /**
+ * dev_decode_panel_timing() - decode panel timings
+ *
+ * Decode display timings from the supplied 'panel-timings' node.
+ *
+ * @dev: device to read DT display timings from. The node linked to the device
+ *       contains a child node called 'display-timings' which in turn contains
+ *       one or more display timing nodes.
+ * @config: place to put timings
+ * Return: 0 if OK, -FDT_ERR_NOTFOUND if not found
+ */
+int dev_decode_panel_timing(const struct udevice *dev,
+			    struct display_timing *config);
+
+/**
  * dev_get_phy_node() - Get PHY node for a MAC (if not fixed-link)
  *
  * This function parses PHY handle from the Ethernet controller's ofnode
@@ -1183,6 +1197,12 @@
 	return ofnode_decode_display_timing(dev_ofnode(dev), index, config);
 }
 
+static inline int dev_decode_panel_timing(const struct udevice *dev,
+					  struct display_timing *config)
+{
+	return ofnode_decode_panel_timing(dev_ofnode(dev), config);
+}
+
 static inline ofnode dev_get_phy_node(const struct udevice *dev)
 {
 	return ofnode_get_phy_node(dev_ofnode(dev));