[PATCH v3 2/2] drm/panel: simple: Add support for ddc-only panel

[linux-kernel-dev at beckhoff.com]

From: Patrick Bruenn <p.bruenn at beckhoff.com>

This is a fix for the CX9020 Embedded PC. On that device the 24-bit
parallel-display signal of the imx53 is combined with an I2C channel
and converted to DVI-D port. Devicetree magic always requires a panel
connected to the parallel-display port.
We add an empty panel_desc, to get recognized by the panel-simple
driver, which can then use the ddc bus to read the panels configuration.

Signed-off-by: Patrick Bruenn <p.bruenn at beckhoff.com>
---
 drivers/gpu/drm/panel/panel-simple.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/gpu/drm/panel/panel-simple.c b/drivers/gpu/drm/panel/panel-simple.c
index c4566ce8fda7..52b2a7fb59ed 100644
--- a/drivers/gpu/drm/panel/panel-simple.c
+++ b/drivers/gpu/drm/panel/panel-simple.c
@@ -1856,6 +1856,9 @@ static const struct panel_desc winstar_wf35ltiacd = {
 	.bus_format = MEDIA_BUS_FMT_RGB888_1X24,
 };
 
+static const struct panel_desc simple_ddc_only = {
+};
+
 static const struct of_device_id platform_of_match[] = {
 	{
 		.compatible = "ampire,am-480272h3tmqw-t01h",
@@ -2050,6 +2053,9 @@ static const struct of_device_id platform_of_match[] = {
 		.compatible = "winstar,wf35ltiacd",
 		.data = &winstar_wf35ltiacd,
 	}, {
+		.compatible = "simple,ddc-only",
+		.data = &simple_ddc_only,
+	}, {
 		/* sentinel */
 	}
 };
-- 
2.11.0