From 77f8fca396c1c04bd2ee464074b6590070d6d670 Mon Sep 17 00:00:00 2001
From: Javier Martinez Canillas <javierm@redhat.com>
Date: Fri, 17 Dec 2021 01:37:51 +0100
Subject: drm/tilcdc: Add support for the nomodeset kernel parameter
Git-commit: 9b71ce89b55565ecce1b189e216048cd1348e36a
Patch-mainline: v5.18-rc1
References: jsc#PED-1166 jsc#PED-1168 jsc#PED-1170 jsc#PED-1218 jsc#PED-1220 jsc#PED-1222 jsc#PED-1223 jsc#PED-1225

According to disable Documentation/admin-guide/kernel-parameters.txt, this
parameter can be used to disable kernel modesetting.

DRM drivers will not perform display-mode changes or accelerated rendering
and only the system framebuffer will be available if it was set-up.

But only a few DRM drivers currently check for nomodeset, make this driver
to also support the command line parameter.

Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Acked-by: Jyri Sarha <jyri.sarha@iki.fi>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20211217003752.3946210-37-javierm@redhat.com
Acked-by: Patrik Jakobsson <pjakobsson@suse.de>
---
 drivers/gpu/drm/tilcdc/tilcdc_drv.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/gpu/drm/tilcdc/tilcdc_drv.c b/drivers/gpu/drm/tilcdc/tilcdc_drv.c
index cc567c87057d..eee3c447fbac 100644
--- a/drivers/gpu/drm/tilcdc/tilcdc_drv.c
+++ b/drivers/gpu/drm/tilcdc/tilcdc_drv.c
@@ -604,6 +604,9 @@ static struct platform_driver tilcdc_platform_driver = {
 
 static int __init tilcdc_drm_init(void)
 {
+	if (drm_firmware_drivers_only())
+		return -ENODEV;
+
 	DBG("init");
 	tilcdc_panel_init();
 	return platform_driver_register(&tilcdc_platform_driver);
-- 
2.38.1