[PATCH v3 15/18] drm/sysfb: efidrm: Add EDID support

[Thomas Zimmermann]

Enable the connector's EDID property if edid_info contains valid
data. Exports the EDID via sysfs for user-space compositors.

EDID information is not always available. Depending on the system
and kernel configuration, it is either provided by the boot loader
or read by the kernel during early boot stages.

As of now, there's only one EFI display, so that EDID data always
belongs to this output. This might change if there's ever more than
one EFI display in the system.

Signed-off-by: Thomas Zimmermann <tzimmermann at suse.de>
Reviewed-by: Javier Martinez Canillas <javierm at redhat.com>
---
 drivers/gpu/drm/sysfb/efidrm.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/drivers/gpu/drm/sysfb/efidrm.c b/drivers/gpu/drm/sysfb/efidrm.c
index 5c1876e34a047..af90064a4c04f 100644
--- a/drivers/gpu/drm/sysfb/efidrm.c
+++ b/drivers/gpu/drm/sysfb/efidrm.c
@@ -13,6 +13,7 @@
 #include <drm/drm_damage_helper.h>
 #include <drm/drm_device.h>
 #include <drm/drm_drv.h>
+#include <drm/drm_edid.h>
 #include <drm/drm_fbdev_shmem.h>
 #include <drm/drm_framebuffer.h>
 #include <drm/drm_gem_atomic_helper.h>
@@ -22,6 +23,7 @@
 #include <drm/drm_modeset_helper_vtables.h>
 #include <drm/drm_probe_helper.h>
 
+#include <video/edid.h>
 #include <video/pixel_format.h>
 
 #include "drm_sysfb_helper.h"
@@ -308,6 +310,10 @@ static struct efidrm_device *efidrm_device_create(struct drm_driver *drv,
 	drm_dbg(dev, "framebuffer format=%p4cc, size=%dx%d, stride=%d bytes\n",
 		&format->format, width, height, stride);
 
+#ifdef CONFIG_X86
+	if (drm_edid_header_is_valid(edid_info.dummy) == 8)
+		sysfb->edid = edid_info.dummy;
+#endif
 	sysfb->fb_mode = drm_sysfb_mode(width, height, 0, 0);
 	sysfb->fb_format = format;
 	sysfb->fb_pitch = stride;
@@ -413,6 +419,8 @@ static struct efidrm_device *efidrm_device_create(struct drm_driver *drv,
 	drm_connector_set_panel_orientation_with_quirk(connector,
 						       DRM_MODE_PANEL_ORIENTATION_UNKNOWN,
 						       width, height);
+	if (sysfb->edid)
+		drm_connector_attach_edid_property(connector);
 
 	ret = drm_connector_attach_encoder(connector, encoder);
 	if (ret)
-- 
2.49.0