From: Abhinav Kumar <[email protected]> If the DP controller is capable of supporting multiple streams then initialize the DP sink in MST mode by programming the DP_MSTM_CTRL DPCD register to enable MST mode.
Signed-off-by: Abhinav Kumar <[email protected]> Signed-off-by: Yongxing Mou <[email protected]> --- drivers/gpu/drm/msm/dp/dp_display.c | 48 +++++++++++++++++++++++++++++++------ 1 file changed, 41 insertions(+), 7 deletions(-) diff --git a/drivers/gpu/drm/msm/dp/dp_display.c b/drivers/gpu/drm/msm/dp/dp_display.c index 5786e598a406..c3be656f10ee 100644 --- a/drivers/gpu/drm/msm/dp/dp_display.c +++ b/drivers/gpu/drm/msm/dp/dp_display.c @@ -14,6 +14,7 @@ #include <linux/string_choices.h> #include <drm/display/drm_dp_aux_bus.h> #include <drm/display/drm_hdmi_audio_helper.h> +#include <drm/display/drm_dp_mst_helper.h> #include <drm/drm_edid.h> #include "msm_drv.h" @@ -270,6 +271,31 @@ static int msm_dp_display_lttpr_init(struct msm_dp_display_private *dp, u8 *dpcd return lttpr_count; } +static void msm_dp_display_mst_init(struct msm_dp_display_private *dp) +{ + u8 old_mstm_ctrl; + struct msm_dp *msm_dp = &dp->msm_dp_display; + int ret; + + /* clear sink MST state */ + drm_dp_dpcd_read_byte(dp->aux, DP_MSTM_CTRL, &old_mstm_ctrl); + + ret = drm_dp_dpcd_write_byte(dp->aux, DP_MSTM_CTRL, 0); + if (ret < 0) { + DRM_ERROR("failed to clear DP_MSTM_CTRL, ret=%d\n", ret); + return; + } + + ret = drm_dp_dpcd_write_byte(dp->aux, DP_MSTM_CTRL, + DP_MST_EN | DP_UP_REQ_EN | DP_UPSTREAM_IS_SRC); + if (ret < 0) { + DRM_ERROR("sink MST enablement failed\n"); + return; + } + + msm_dp->mst_active = true; +} + static int msm_dp_display_process_hpd_high(struct msm_dp_display_private *dp) { struct drm_connector *connector = dp->msm_dp_display.connector; @@ -288,14 +314,19 @@ static int msm_dp_display_process_hpd_high(struct msm_dp_display_private *dp) if (rc) goto end; - drm_edid = drm_edid_read_ddc(connector, &dp->aux->ddc); - drm_edid_connector_update(connector, drm_edid); + if (!(dp->max_stream > 1) || !drm_dp_read_mst_cap(dp->aux, dp->panel->dpcd)) { + drm_edid = drm_edid_read_ddc(connector, &dp->aux->ddc); + drm_edid_connector_update(connector, drm_edid); - if (!drm_edid) { - DRM_ERROR("panel edid read failed\n"); - /* check edid read fail is due to unplug */ - if (!msm_dp_aux_is_link_connected(dp->aux)) - return -ETIMEDOUT; + if (!drm_edid) { + DRM_ERROR("panel edid read failed\n"); + /* check edid read fail is due to unplug */ + if (!msm_dp_aux_is_link_connected(dp->aux)) + return -ETIMEDOUT; + } + + if (rc) + goto end; } msm_dp_link_process_request(dp->link); @@ -317,6 +348,9 @@ static int msm_dp_display_process_hpd_high(struct msm_dp_display_private *dp) */ msm_dp_link_psm_config(dp->link, &dp->panel->link_info, false); + if (dp->max_stream > 1 && drm_dp_read_mst_cap(dp->aux, dp->panel->dpcd)) + msm_dp_display_mst_init(dp); + msm_dp_link_reset_phy_params_vx_px(dp->link); end: -- 2.43.0
