diff options
Diffstat (limited to 'drivers/gpu/drm/drm_dp_helper.c')
| -rw-r--r-- | drivers/gpu/drm/drm_dp_helper.c | 54 |
1 files changed, 54 insertions, 0 deletions
diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c index 5d8c9bd700c9..63ac94c54e95 100644 --- a/drivers/gpu/drm/drm_dp_helper.c +++ b/drivers/gpu/drm/drm_dp_helper.c @@ -809,6 +809,60 @@ int drm_dp_downstream_max_bpc(const u8 dpcd[DP_RECEIVER_CAP_SIZE], EXPORT_SYMBOL(drm_dp_downstream_max_bpc); /** + * drm_dp_downstream_mode() - return a mode for downstream facing port + * @dpcd: DisplayPort configuration data + * @port_cap: port capabilities + * + * Provides a suitable mode for downstream facing ports without EDID. + * + * Returns: A new drm_display_mode on success or NULL on failure + */ +struct drm_display_mode * +drm_dp_downstream_mode(struct drm_device *dev, + const u8 dpcd[DP_RECEIVER_CAP_SIZE], + const u8 port_cap[4]) + +{ + u8 vic; + + if (!drm_dp_is_branch(dpcd)) + return NULL; + + if (dpcd[DP_DPCD_REV] < 0x11) + return NULL; + + switch (port_cap[0] & DP_DS_PORT_TYPE_MASK) { + case DP_DS_PORT_TYPE_NON_EDID: + switch (port_cap[0] & DP_DS_NON_EDID_MASK) { + case DP_DS_NON_EDID_720x480i_60: + vic = 6; + break; + case DP_DS_NON_EDID_720x480i_50: + vic = 21; + break; + case DP_DS_NON_EDID_1920x1080i_60: + vic = 5; + break; + case DP_DS_NON_EDID_1920x1080i_50: + vic = 20; + break; + case DP_DS_NON_EDID_1280x720_60: + vic = 4; + break; + case DP_DS_NON_EDID_1280x720_50: + vic = 19; + break; + default: + return NULL; + } + return drm_display_mode_from_cea_vic(dev, vic); + default: + return NULL; + } +} +EXPORT_SYMBOL(drm_dp_downstream_mode); + +/** * drm_dp_downstream_id() - identify branch device * @aux: DisplayPort AUX channel * @id: DisplayPort branch device id |