[PATCH v6 07/10] drm-bridge: it66121: Use fwnode APIs to acquire device properties

[Sui Jingfeng <sui.jingfeng@linux.dev>]

Make this driver less DT-dependent by calling the newly created helpers,
also switch to use fwnode APIs to acquire additional device properties.
A side benifit is that boilerplates get reduced, no functional changes
for DT-based systems.

Signed-off-by: Sui Jingfeng <sui.jingfeng@linux.dev>
---
 drivers/gpu/drm/bridge/ite-it66121.c | 55 +++++++++++++++++-----------
 1 file changed, 34 insertions(+), 21 deletions(-)

diff --git a/drivers/gpu/drm/bridge/ite-it66121.c b/drivers/gpu/drm/bridge/ite-it66121.c
index 8e4fc082bb8c..3fa650f7fec9 100644
--- a/drivers/gpu/drm/bridge/ite-it66121.c
+++ b/drivers/gpu/drm/bridge/ite-it66121.c
@@ -15,7 +15,6 @@
 #include <linux/bitfield.h>
 #include <linux/property.h>
 #include <linux/regmap.h>
-#include <linux/of_graph.h>
 #include <linux/gpio/consumer.h>
 #include <linux/pinctrl/consumer.h>
 #include <linux/regulator/consumer.h>
@@ -1480,7 +1479,7 @@ static int it66121_audio_codec_init(struct it66121_ctx *ctx, struct device *dev)
 
 	dev_dbg(dev, "%s\n", __func__);
 
-	if (!of_property_read_bool(dev->of_node, "#sound-dai-cells")) {
+	if (!fwnode_property_present(dev_fwnode(dev), "#sound-dai-cells")) {
 		dev_info(dev, "No \"#sound-dai-cells\", no audio\n");
 		return 0;
 	}
@@ -1503,13 +1502,36 @@ static const char * const it66121_supplies[] = {
 	"vcn33", "vcn18", "vrf12"
 };
 
+static int it66121_read_bus_width(struct fwnode_handle *fwnode, u32 *bus_width)
+{
+	struct fwnode_handle *endpoint;
+	u32 val;
+	int ret;
+
+	endpoint = fwnode_graph_get_endpoint_by_id(fwnode, 0, 0, 0);
+	if (!endpoint)
+		return -EINVAL;
+
+	ret = fwnode_property_read_u32(endpoint, "bus-width", &val);
+	fwnode_handle_put(endpoint);
+	if (ret)
+		return ret;
+
+	if (val != 12 && val != 24)
+		return -EINVAL;
+
+	*bus_width = val;
+
+	return 0;
+}
+
 static int it66121_probe(struct i2c_client *client)
 {
 	u32 revision_id, vendor_ids[2] = { 0 }, device_ids[2] = { 0 };
-	struct device_node *ep;
 	int ret;
 	struct it66121_ctx *ctx;
 	struct device *dev = &client->dev;
+	struct fwnode_handle *fwnode = dev_fwnode(dev);
 
 	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
 		dev_err(dev, "I2C check functionality failed.\n");
@@ -1520,29 +1542,20 @@ static int it66121_probe(struct i2c_client *client)
 	if (!ctx)
 		return -ENOMEM;
 
-	ep = of_graph_get_endpoint_by_regs(dev->of_node, 0, 0);
-	if (!ep)
-		return -EINVAL;
-
 	ctx->dev = dev;
 	ctx->client = client;
 	ctx->info = i2c_get_match_data(client);
 
-	of_property_read_u32(ep, "bus-width", &ctx->bus_width);
-	of_node_put(ep);
-
-	if (ctx->bus_width != 12 && ctx->bus_width != 24)
-		return -EINVAL;
-
-	ep = of_graph_get_remote_node(dev->of_node, 1, -1);
-	if (!ep) {
-		dev_err(ctx->dev, "The endpoint is unconnected\n");
-		return -EINVAL;
-	}
+	ret = it66121_read_bus_width(fwnode, &ctx->bus_width);
+	if (ret)
+		return ret;
 
-	ctx->next_bridge = of_drm_find_bridge(ep);
-	of_node_put(ep);
-	if (!ctx->next_bridge) {
+	ctx->next_bridge = drm_bridge_find_next_bridge_by_fwnode(fwnode, 1);
+	if (IS_ERR(ctx->next_bridge)) {
+		ret = PTR_ERR(ctx->next_bridge);
+		dev_err(dev, "Error in founding the next bridge: %d\n", ret);
+		return ret;
+	} else if (!ctx->next_bridge) {
 		dev_dbg(ctx->dev, "Next bridge not found, deferring probe\n");
 		return -EPROBE_DEFER;
 	}
-- 
2.34.1