linux-kernel - [PATCH] drm/bridge: lontium-lt9611uxc: use irq as optional parameter

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Message-Id: <20251208161708.3763458-1-vovchkir@gmail.com>
Date: Mon,  8 Dec 2025 19:17:08 +0300
From: Vladimir Yakovlev <vovchkir@...il.com>
To: Dmitry Baryshkov <dmitry.baryshkov@....qualcomm.com>
Cc: Vladimir Yakovlev <vovchkir@...il.com>,
	Andrzej Hajda <andrzej.hajda@...el.com>,
	Neil Armstrong <neil.armstrong@...aro.org>,
	Robert Foss <rfoss@...nel.org>,
	Laurent Pinchart <Laurent.pinchart@...asonboard.com>,
	Jonas Karlman <jonas@...boo.se>,
	Jernej Skrabec <jernej.skrabec@...il.com>,
	Maarten Lankhorst <maarten.lankhorst@...ux.intel.com>,
	Maxime Ripard <mripard@...nel.org>,
	Thomas Zimmermann <tzimmermann@...e.de>,
	David Airlie <airlied@...il.com>,
	Simona Vetter <simona@...ll.ch>,
	dri-devel@...ts.freedesktop.org,
	linux-kernel@...r.kernel.org
Subject: [PATCH] drm/bridge: lontium-lt9611uxc: use irq as optional parameter

On some systems the interrupt pin may not be used.
In this case we exclude DRM_BRIDGE_OP_HPD from supported operations,
after which a polling thread is started to detect the connection.
(the default polling period for DRM is 10 seconds)

Signed-off-by: Vladimir Yakovlev <vovchkir@...il.com>
---
 drivers/gpu/drm/bridge/lontium-lt9611uxc.c | 26 ++++++++++++++--------
 1 file changed, 17 insertions(+), 9 deletions(-)

diff --git a/drivers/gpu/drm/bridge/lontium-lt9611uxc.c b/drivers/gpu/drm/bridge/lontium-lt9611uxc.c
index 3868ad05e011..4d550cd1a9a1 100644
--- a/drivers/gpu/drm/bridge/lontium-lt9611uxc.c
+++ b/drivers/gpu/drm/bridge/lontium-lt9611uxc.c
@@ -851,19 +851,25 @@ static int lt9611uxc_probe(struct i2c_client *client)
 	init_waitqueue_head(&lt9611uxc->wq);
 	INIT_WORK(&lt9611uxc->work, lt9611uxc_hpd_work);
 
-	ret = request_threaded_irq(client->irq, NULL,
-				   lt9611uxc_irq_thread_handler,
-				   IRQF_ONESHOT, "lt9611uxc", lt9611uxc);
-	if (ret) {
-		dev_err(dev, "failed to request irq\n");
-		goto err_disable_regulators;
+	if (client->irq) {
+		ret = request_threaded_irq(client->irq, NULL,
+					   lt9611uxc_irq_thread_handler,
+					   IRQF_ONESHOT, "lt9611uxc", lt9611uxc);
+		if (ret) {
+			dev_err(dev, "failed to request irq\n");
+			goto err_disable_regulators;
+		}
+		dev_dbg(dev, "Uses IRQ\n");
+	} else {
+		dev_warn(dev, "The interrupt (IRQ) is not specified in the DTS.\n");
+		dev_warn(dev, "Check the interrupt (IRQ) or polling will be used!!!\n");
 	}
 
 	i2c_set_clientdata(client, lt9611uxc);
 
 	lt9611uxc->bridge.of_node = client->dev.of_node;
 	lt9611uxc->bridge.ops = DRM_BRIDGE_OP_DETECT | DRM_BRIDGE_OP_EDID;
-	if (lt9611uxc->hpd_supported)
+	if (lt9611uxc->hpd_supported && client->irq)
 		lt9611uxc->bridge.ops |= DRM_BRIDGE_OP_HPD;
 	lt9611uxc->bridge.type = DRM_MODE_CONNECTOR_HDMIA;
 
@@ -892,7 +898,8 @@ static int lt9611uxc_probe(struct i2c_client *client)
 	return 0;
 
 err_remove_bridge:
-	free_irq(client->irq, lt9611uxc);
+	if (client->irq)
+		free_irq(client->irq, lt9611uxc);
 	cancel_work_sync(&lt9611uxc->work);
 	drm_bridge_remove(&lt9611uxc->bridge);
 
@@ -910,7 +917,8 @@ static void lt9611uxc_remove(struct i2c_client *client)
 {
 	struct lt9611uxc *lt9611uxc = i2c_get_clientdata(client);
 
-	free_irq(client->irq, lt9611uxc);
+	if (client->irq)
+		free_irq(client->irq, lt9611uxc);
 	cancel_work_sync(&lt9611uxc->work);
 	lt9611uxc_audio_exit(lt9611uxc);
 	drm_bridge_remove(&lt9611uxc->bridge);
-- 
2.34.1