[PATCH v13 05/10] drm/bridge: anx7625: Check for Type-C during panel registration - Pin-yen Lin

From: Pin-yen Lin <treapking@chromium.org>
To: Andrzej Hajda <andrzej.hajda@intel.com>,
	Neil Armstrong <neil.armstrong@linaro.org>,
	Robert Foss <rfoss@kernel.org>,
	Laurent Pinchart <Laurent.pinchart@ideasonboard.com>,
	Jonas Karlman <jonas@kwiboo.se>,
	Jernej Skrabec <jernej.skrabec@gmail.com>,
	David Airlie <airlied@gmail.com>, Daniel Vetter <daniel@ffwll.ch>,
	Rob Herring <robh+dt@kernel.org>,
	Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
	Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
	Daniel Scally <djrscally@gmail.com>,
	Heikki Krogerus <heikki.krogerus@linux.intel.com>,
	Sakari Ailus <sakari.ailus@linux.intel.com>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	"Rafael J . Wysocki" <rafael@kernel.org>,
	Prashant Malani <pmalani@chromium.org>,
	Benson Leung <bleung@chromium.org>,
	Guenter Roeck <groeck@chromium.org>
Cc: "Xin Ji" <xji@analogixsemi.com>,
	"Javier Martinez Canillas" <javierm@redhat.com>,
	"Lyude Paul" <lyude@redhat.com>,
	linux-kernel@vger.kernel.org,
	"Pin-yen Lin" <treapking@chromium.org>,
	"AngeloGioacchino Del Regno"
	<angelogioacchino.delregno@collabora.com>,
	chrome-platform@lists.linux.dev,
	"Nícolas F . R . A . Prado" <nfraprado@collabora.com>,
	"Marek Vasut" <marex@denx.de>,
	"Hsin-Yi Wang" <hsinyi@chromium.org>,
	devicetree@vger.kernel.org, "Allen Chen" <allen.chen@ite.com.tw>,
	dri-devel@lists.freedesktop.org,
	"Thomas Zimmermann" <tzimmermann@suse.de>,
	"Stephen Boyd" <swboyd@chromium.org>,
	linux-acpi@vger.kernel.org,
	"Uwe Kleine-König" <u.kleine-koenig@pengutronix.de>
Subject: [PATCH v13 05/10] drm/bridge: anx7625: Check for Type-C during panel registration
Date: Fri,  3 Mar 2023 22:33:45 +0800	[thread overview]
Message-ID: <20230303143350.815623-6-treapking@chromium.org> (raw)
In-Reply-To: <20230303143350.815623-1-treapking@chromium.org>

The output port endpoints can be connected to USB-C connectors.
Running drm_of_find_panel_or_bridge() with such endpoints leads to
a continuous return value of -EPROBE_DEFER, even though there is
no panel present.

To avoid this, check for the existence of a "mode-switch" property in
the port endpoint, and skip panel registration completely if so.

Signed-off-by: Pin-yen Lin <treapking@chromium.org>

---

Changes in v13:
- Use the new typec_mode_switch_node_count helper

Changes in v12:
- Updated to use fwnode_for_each_typec_mode_switch macro
- Dropped collected tags

Changes in v10:
- Collected Reviewed-by and Tested-by tags

Changes in v6:
- New in v6

 drivers/gpu/drm/bridge/analogix/anx7625.c | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/bridge/analogix/anx7625.c b/drivers/gpu/drm/bridge/analogix/anx7625.c
index 6846199a2ee1..3f6bf7674d32 100644
--- a/drivers/gpu/drm/bridge/analogix/anx7625.c
+++ b/drivers/gpu/drm/bridge/analogix/anx7625.c
@@ -1648,7 +1648,8 @@ static int anx7625_get_swing_setting(struct device *dev,
 static int anx7625_parse_dt(struct device *dev,
 			    struct anx7625_platform_data *pdata)
 {
-	struct device_node *np = dev->of_node, *ep0;
+	struct device_node *np = dev->of_node, *ep0, *port_node;
+	unsigned int count;
 	int bus_type, mipi_lanes;
 
 	anx7625_get_swing_setting(dev, pdata);
@@ -1687,6 +1688,15 @@ static int anx7625_parse_dt(struct device *dev,
 	if (of_property_read_bool(np, "analogix,audio-enable"))
 		pdata->audio_en = 1;
 
+	/*
+	 * Don't bother finding a panel if a Type-C `mode-switch` property is
+	 * present in one of the endpoints in the output port.
+	 */
+	port_node = of_graph_get_port_by_id(np, 1);
+	count = typec_mode_switch_node_count(&port_node->fwnode);
+	if (count)
+		return 0;
+
 	pdata->panel_bridge = devm_drm_of_get_bridge(dev, np, 1, 0);
 	if (IS_ERR(pdata->panel_bridge)) {
 		if (PTR_ERR(pdata->panel_bridge) == -ENODEV) {
-- 
2.40.0.rc0.216.gc4246ad0f0-goog

