linux-kernel - [PATCH 2/5] drm/bridge: simple-bridge: Extend match support for non-DT based systems

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Date: Tue, 23 Jan 2024 00:32:17 +0800
From: Sui Jingfeng <sui.jingfeng@...ux.dev>
To: David Airlie <airlied@...il.com>
Cc: Neil Armstrong <neil.armstrong@...aro.org>,
	Maxime Ripard <mripard@...nel.org>,
	Thomas Zimmermann <tzimmermann@...e.de>,
	Daniel Vetter <daniel@...ll.ch>,
	Laurent Pinchart <Laurent.pinchart@...asonboard.com>,
	dri-devel@...ts.freedesktop.org,
	linux-kernel@...r.kernel.org,
	Sui Jingfeng <sui.jingfeng@...ux.dev>
Subject: [PATCH 2/5] drm/bridge: simple-bridge: Extend match support for non-DT based systems

Which is intended to be used on non-DT environment, where the simple-bridge
platform device is created by either the display controller driver side or
platform firmware subsystem. To avoid duplication and to keep consistent,
we choose to reuse the OF match tables. Because the potentional user may
not has a of_node attached, nor a ACPI match id. If this is the case,
a software node string property can be provide to fill the niche.

Signed-off-by: Sui Jingfeng <sui.jingfeng@...ux.dev>
---
 drivers/gpu/drm/bridge/simple-bridge.c | 24 +++++++++++++++++++++++-
 1 file changed, 23 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/bridge/simple-bridge.c b/drivers/gpu/drm/bridge/simple-bridge.c
index cbe8e778d7c7..595f672745b9 100644
--- a/drivers/gpu/drm/bridge/simple-bridge.c
+++ b/drivers/gpu/drm/bridge/simple-bridge.c
@@ -166,6 +166,24 @@ static const struct drm_bridge_funcs simple_bridge_bridge_funcs = {
 	.disable	= simple_bridge_disable,
 };
 
+static const void *simple_bridge_get_match_data(const struct device *dev)
+{
+	const struct of_device_id *matches = dev->driver->of_match_table;
+
+	/* Try to get the match data by software node */
+	while (matches) {
+		if (!matches->compatible[0])
+			break;
+
+		if (device_is_compatible(dev, matches->compatible))
+			return matches->data;
+
+		matches++;
+	}
+
+	return NULL;
+}
+
 static int simple_bridge_probe(struct platform_device *pdev)
 {
 	struct simple_bridge *sbridge;
@@ -176,7 +194,10 @@ static int simple_bridge_probe(struct platform_device *pdev)
 		return -ENOMEM;
 	platform_set_drvdata(pdev, sbridge);
 
-	sbridge->info = of_device_get_match_data(&pdev->dev);
+	if (pdev->dev.of_node)
+		sbridge->info = of_device_get_match_data(&pdev->dev);
+	else
+		sbridge->info = simple_bridge_get_match_data(&pdev->dev);
 
 	/* Get the next bridge in the pipeline. */
 	remote = of_graph_get_remote_node(pdev->dev.of_node, 1, -1);
@@ -309,3 +330,4 @@ module_platform_driver(simple_bridge_driver);
 MODULE_AUTHOR("Maxime Ripard <maxime.ripard@...e-electrons.com>");
 MODULE_DESCRIPTION("Simple DRM bridge driver");
 MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:simple-bridge");
-- 
2.25.1