drm/radeon/kms: add support for hardcoded edids in rom (v2)

Some servers hardcode an edid in rom so that they will
work properly with KVMs.  This is a port of the relevant
code from the ddx.

[airlied: reworked to validate edid at boot stage - and
remove special quirk, if there is a valid EDID in the BIOS rom
we'll just try and use it.]

Signed-off-by: Alex Deucher <alexdeucher@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

3 files changed, 51 insertions, 2 deletions

diff --git a/drivers/gpu/drm/radeon/radeon_combios.c b/drivers/gpu/drm/radeon/radeon_combios.c
index e208d730f514..257ce1774e40 100644
--- a/drivers/gpu/drm/radeon/radeon_combios.c
+++ b/drivers/gpu/drm/radeon/radeon_combios.c
@@ -443,6 +443,39 @@ static uint16_t combios_get_table_offset(struct drm_device *dev,
 
 }
 
+bool radeon_combios_check_hardcoded_edid(struct radeon_device *rdev)
+{
+	int edid_info;
+	struct edid *edid;
+	edid_info = combios_get_table_offset(rdev->ddev, COMBIOS_HARDCODED_EDID_TABLE);
+	if (!edid_info)
+		return false;
+
+	edid = kmalloc(EDID_LENGTH * (DRM_MAX_EDID_EXT_NUM + 1),
+		       GFP_KERNEL);
+	if (edid == NULL)
+		return false;
+
+	memcpy((unsigned char *)edid,
+	       (unsigned char *)(rdev->bios + edid_info), EDID_LENGTH);
+
+	if (!drm_edid_is_valid(edid)) {
+		kfree(edid);
+		return false;
+	}
+
+	rdev->mode_info.bios_hardcoded_edid = edid;
+	return true;
+}
+
+struct edid *
+radeon_combios_get_hardcoded_edid(struct radeon_device *rdev)
+{
+	if (rdev->mode_info.bios_hardcoded_edid)
+		return rdev->mode_info.bios_hardcoded_edid;
+	return NULL;
+}
+
 static struct radeon_i2c_bus_rec combios_setup_i2c_bus(struct radeon_device *rdev,
 						       int ddc_line)
 {
diff --git a/drivers/gpu/drm/radeon/radeon_display.c b/drivers/gpu/drm/radeon/radeon_display.c
index ec3166bfaa49..79634da7c311 100644
--- a/drivers/gpu/drm/radeon/radeon_display.c
+++ b/drivers/gpu/drm/radeon/radeon_display.c
@@ -352,6 +352,8 @@ static bool radeon_setup_enc_conn(struct drm_device *dev)
 
 int radeon_ddc_get_modes(struct radeon_connector *radeon_connector)
 {
+	struct drm_device *dev = radeon_connector->base.dev;
+	struct radeon_device *rdev = dev->dev_private;
 	int ret = 0;
 
 	if ((radeon_connector->base.connector_type == DRM_MODE_CONNECTOR_DisplayPort) ||
@@ -366,7 +368,9 @@ int radeon_ddc_get_modes(struct radeon_connector *radeon_connector)
 	if (!radeon_connector->edid) {
 		radeon_connector->edid = drm_get_edid(&radeon_connector->base, &radeon_connector->ddc_bus->adapter);
 	}
-
+	/* some servers provide a hardcoded edid in rom for KVMs */
+	if (!radeon_connector->edid)
+		radeon_connector->edid = radeon_combios_get_hardcoded_edid(rdev);
 	if (radeon_connector->edid) {
 		drm_mode_connector_update_edid_property(&radeon_connector->base, radeon_connector->edid);
 		ret = drm_add_edid_modes(&radeon_connector->base, radeon_connector->edid);
@@ -829,6 +833,12 @@ int radeon_modeset_init(struct radeon_device *rdev)
 		return ret;
 	}
 
+	/* check combios for a valid hardcoded EDID - Sun servers */
+	if (!rdev->is_atom_bios) {
+		/* check for hardcoded EDID in BIOS */
+		radeon_combios_check_hardcoded_edid(rdev);
+	}
+
 	if (rdev->flags & RADEON_SINGLE_CRTC)
 		num_crtc = 1;
 
@@ -850,6 +860,8 @@ int radeon_modeset_init(struct radeon_device *rdev)
 
 void radeon_modeset_fini(struct radeon_device *rdev)
 {
+	kfree(rdev->mode_info.bios_hardcoded_edid);
+
 	if (rdev->mode_info.mode_config_initialized) {
 		radeon_hpd_fini(rdev);
 		drm_mode_config_cleanup(rdev->ddev);
diff --git a/drivers/gpu/drm/radeon/radeon_mode.h b/drivers/gpu/drm/radeon/radeon_mode.h
index b884bacf09ff..71439ba2feeb 100644
--- a/drivers/gpu/drm/radeon/radeon_mode.h
+++ b/drivers/gpu/drm/radeon/radeon_mode.h
@@ -207,7 +207,8 @@ struct radeon_mode_info {
 	struct drm_property *tv_std_property;
 	/* legacy TMDS PLL detect */
 	struct drm_property *tmds_pll_property;
-
+	/* hardcoded DFP edid from BIOS */
+	struct edid *bios_hardcoded_edid;
 };
 
 #define MAX_H_CODE_TIMING_LEN 32
@@ -479,6 +480,9 @@ extern int radeon_crtc_cursor_set(struct drm_crtc *crtc,
 extern int radeon_crtc_cursor_move(struct drm_crtc *crtc,
 				   int x, int y);
 
+extern bool radeon_combios_check_hardcoded_edid(struct radeon_device *rdev);
+extern struct edid *
+radeon_combios_get_hardcoded_edid(struct radeon_device *rdev);
 extern bool radeon_atom_get_clock_info(struct drm_device *dev);
 extern bool radeon_combios_get_clock_info(struct drm_device *dev);
 extern struct radeon_encoder_atom_dig *