[PATCH 1/2] drm/vesadrm: Match framebuffer device by id instead of driver name

[Yao Zi]

Currently the driver matches the platform framebuffer device registered
by sysfb through driver name, "vesa-framebuffer", this is a little
confusing since this driver registers a DRM device, instead of a
framebuffer.

Moreover, we have a driver with the same name, enabled by
CONFIG_FB_VESA, that acts as a consumer of vesa-framebuffer as well.
They cannot be both loaded into the kernel.

Making these two drivers coexist is sometimes useful, e.g., a
distribution may want to build fbcon into the kernel image for debugging
purpose, but keep the whole DRM subsystem enabled as module. In such
case vesadrm could serve as a solution for running DRM-specific
userspace programs on platforms with only VESA VBIOS available.

Let's rename the driver as "vesa-display" to avoid possible confusion.
A platform_device_id table is introduced to match "vesa-framebuffer"
devices.

Signed-off-by: Yao Zi <ziyao@xxxxxxxxxxx>
---
 drivers/gpu/drm/sysfb/vesadrm.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/sysfb/vesadrm.c b/drivers/gpu/drm/sysfb/vesadrm.c
index 90615e9ac86b..16635dc3d5cc 100644
--- a/drivers/gpu/drm/sysfb/vesadrm.c
+++ b/drivers/gpu/drm/sysfb/vesadrm.c
@@ -3,6 +3,7 @@
 #include <linux/aperture.h>
 #include <linux/ioport.h>
 #include <linux/limits.h>
+#include <linux/mod_devicetable.h>
 #include <linux/platform_device.h>
 #include <linux/screen_info.h>
 
@@ -517,10 +518,17 @@ static void vesadrm_remove(struct platform_device *pdev)
 	drm_dev_unplug(dev);
 }
 
+static const struct platform_device_id vesadrm_platform_id[] = {
+	{ "vesa-framebuffer" },
+	{ },
+};
+MODULE_DEVICE_TABLE(platform, vesadrm_platform_id);
+
 static struct platform_driver vesadrm_platform_driver = {
 	.driver = {
-		.name = "vesa-framebuffer",
+		.name = "vesa-display",
 	},
+	.id_table = vesadrm_platform_id,
 	.probe = vesadrm_probe,
 	.remove = vesadrm_remove,
 };
-- 
2.50.1