drm: convert drivers to use of_graph_get_remote_node

Convert drivers to use the new of_graph_get_remote_node() helper
instead of parsing the endpoint node and then getting the remote device
node. Now drivers can just specify the device node and which
port/endpoint and get back the connected remote device node. The details
of the graph binding are nicely abstracted into the core OF graph code.

This changes some error messages to debug messages (in the graph core).
Graph connections are often "no connects" depending on the particular
board, so we want to avoid spurious messages. Plus the kernel is not a
DT validator.

Signed-off-by: Rob Herring <robh@kernel.org>
Acked-by: Neil Armstrong <narmstrong@baylibre.com>
Tested-by: Liviu Dudau <liviu.dudau@arm.com>
Tested-by: Eric Anholt <eric@anholt.net>
Tested-by: Jyri Sarha <jsarha@ti.com>
Tested by: Archit Taneja <architt@codeaurora.org>
Signed-off-by: Sean Paul <seanpaul@chromium.org>

3 files changed, 10 insertions, 32 deletions

diff --git a/drivers/gpu/drm/bridge/adv7511/adv7533.c b/drivers/gpu/drm/bridge/adv7511/adv7533.c
index 8b210373cfa2..ac804f81e2f6 100644
--- a/drivers/gpu/drm/bridge/adv7511/adv7533.c
+++ b/drivers/gpu/drm/bridge/adv7511/adv7533.c
@@ -232,7 +232,6 @@ void adv7533_detach_dsi(struct adv7511 *adv)
 int adv7533_parse_dt(struct device_node *np, struct adv7511 *adv)
 {
 	u32 num_lanes;
-	struct device_node *endpoint;
 
 	of_property_read_u32(np, "adi,dsi-lanes", &num_lanes);
 
@@ -241,17 +240,10 @@ int adv7533_parse_dt(struct device_node *np, struct adv7511 *adv)
 
 	adv->num_dsi_lanes = num_lanes;
 
-	endpoint = of_graph_get_next_endpoint(np, NULL);
-	if (!endpoint)
+	adv->host_node = of_graph_get_remote_node(np, 0, 0);
+	if (!adv->host_node)
 		return -ENODEV;
 
-	adv->host_node = of_graph_get_remote_port_parent(endpoint);
-	if (!adv->host_node) {
-		of_node_put(endpoint);
-		return -ENODEV;
-	}
-
-	of_node_put(endpoint);
 	of_node_put(adv->host_node);
 
 	adv->use_timing_gen = !of_property_read_bool(np,
diff --git a/drivers/gpu/drm/bridge/dumb-vga-dac.c b/drivers/gpu/drm/bridge/dumb-vga-dac.c
index 63e113bd21d2..831a606c4706 100644
--- a/drivers/gpu/drm/bridge/dumb-vga-dac.c
+++ b/drivers/gpu/drm/bridge/dumb-vga-dac.c
@@ -154,21 +154,12 @@ static const struct drm_bridge_funcs dumb_vga_bridge_funcs = {
 
 static struct i2c_adapter *dumb_vga_retrieve_ddc(struct device *dev)
 {
-	struct device_node *end_node, *phandle, *remote;
+	struct device_node *phandle, *remote;
 	struct i2c_adapter *ddc;
 
-	end_node = of_graph_get_endpoint_by_regs(dev->of_node, 1, -1);
-	if (!end_node) {
-		dev_err(dev, "Missing connector endpoint\n");
-		return ERR_PTR(-ENODEV);
-	}
-
-	remote = of_graph_get_remote_port_parent(end_node);
-	of_node_put(end_node);
-	if (!remote) {
-		dev_err(dev, "Enable to parse remote node\n");
+	remote = of_graph_get_remote_node(dev->of_node, 1, -1);
+	if (!remote)
 		return ERR_PTR(-EINVAL);
-	}
 
 	phandle = of_parse_phandle(remote, "ddc-i2c-bus", 0);
 	of_node_put(remote);
diff --git a/drivers/gpu/drm/bridge/ti-tfp410.c b/drivers/gpu/drm/bridge/ti-tfp410.c
index 7d519b46aee4..eee4efda829e 100644
--- a/drivers/gpu/drm/bridge/ti-tfp410.c
+++ b/drivers/gpu/drm/bridge/ti-tfp410.c
@@ -165,18 +165,13 @@ static irqreturn_t tfp410_hpd_irq_thread(int irq, void *arg)
 
 static int tfp410_get_connector_properties(struct tfp410 *dvi)
 {
-	struct device_node *ep = NULL, *connector_node = NULL;
-	struct device_node *ddc_phandle = NULL;
+	struct device_node *connector_node, *ddc_phandle;
 	int ret = 0;
 
 	/* port@1 is the connector node */
-	ep = of_graph_get_endpoint_by_regs(dvi->dev->of_node, 1, -1);
-	if (!ep)
-		goto fail;
-
-	connector_node = of_graph_get_remote_port_parent(ep);
+	connector_node = of_graph_get_remote_node(dvi->dev->of_node, 1, -1);
 	if (!connector_node)
-		goto fail;
+		return -ENODEV;
 
 	dvi->hpd = fwnode_get_named_gpiod(&connector_node->fwnode,
 					"hpd-gpios", 0, GPIOD_IN, "hpd");
@@ -199,10 +194,10 @@ static int tfp410_get_connector_properties(struct tfp410 *dvi)
 	else
 		ret = -EPROBE_DEFER;
 
+	of_node_put(ddc_phandle);
+
 fail:
-	of_node_put(ep);
 	of_node_put(connector_node);
-	of_node_put(ddc_phandle);
 	return ret;
 }