[PATCH v3 18/38] drm/msm/dp: Add support to enable MST in mainlink control

[Yongxing Mou]

From: Abhinav Kumar <quic_abhin...@quicinc.com>

Add support to program the MST enable bit in the mainlink control
register when an MST session is active or being disabled.

Signed-off-by: Abhinav Kumar <quic_abhin...@quicinc.com>
Signed-off-by: Yongxing Mou <yongxing....@oss.qualcomm.com>
---
 drivers/gpu/drm/msm/dp/dp_ctrl.c | 17 +++++++++++++++++
 drivers/gpu/drm/msm/dp/dp_reg.h  |  1 +
 2 files changed, 18 insertions(+)

diff --git a/drivers/gpu/drm/msm/dp/dp_ctrl.c b/drivers/gpu/drm/msm/dp/dp_ctrl.c
index 
16e5ed58e791971d5dca3077cbb77bfcc186505a..d562377a8d2846099bf0f8757128978a162745c3
 100644
--- a/drivers/gpu/drm/msm/dp/dp_ctrl.c
+++ b/drivers/gpu/drm/msm/dp/dp_ctrl.c
@@ -254,6 +254,19 @@ void msm_dp_ctrl_mst_send_act(struct msm_dp_ctrl 
*msm_dp_ctrl)
        return;
 }
 
+static void msm_dp_ctrl_mst_config(struct msm_dp_ctrl_private *ctrl, bool 
enable)
+{
+       u32 mainlink_ctrl;
+
+       mainlink_ctrl = msm_dp_read_link(ctrl, REG_DP_MAINLINK_CTRL);
+       if (enable)
+               mainlink_ctrl |= DP_MAINLINK_CTRL_MST_EN;
+       else
+               mainlink_ctrl &= ~DP_MAINLINK_CTRL_MST_EN;
+
+       msm_dp_write_link(ctrl, REG_DP_MAINLINK_CTRL, mainlink_ctrl);
+}
+
 /*
  * NOTE: resetting DP controller will also clear any pending HPD related 
interrupts
  */
@@ -2656,6 +2669,9 @@ int msm_dp_ctrl_on_stream(struct msm_dp_ctrl 
*msm_dp_ctrl, struct msm_dp_panel *
        msm_dp_ctrl_lane_mapping(ctrl);
        msm_dp_setup_peripheral_flush(ctrl);
 
+       if (ctrl->mst_active)
+               msm_dp_ctrl_mst_config(ctrl, true);
+
        if (msm_dp_panel->stream_id == DP_STREAM_0)
                msm_dp_ctrl_config_ctrl_link(ctrl);
 
@@ -2711,6 +2727,7 @@ void msm_dp_ctrl_off_link(struct msm_dp_ctrl *msm_dp_ctrl)
        phy = ctrl->phy;
 
        msm_dp_ctrl_mainlink_disable(ctrl);
+       msm_dp_ctrl_mst_config(ctrl, false);
 
        msm_dp_ctrl_reset(&ctrl->msm_dp_ctrl);
 
diff --git a/drivers/gpu/drm/msm/dp/dp_reg.h b/drivers/gpu/drm/msm/dp/dp_reg.h
index 
de3d0b8b52c269fd7575edf3f4096a4284ad0b8d..fda847b33f8d0d6ec4d2589586b5a3d6c9b1ccf3
 100644
--- a/drivers/gpu/drm/msm/dp/dp_reg.h
+++ b/drivers/gpu/drm/msm/dp/dp_reg.h
@@ -128,6 +128,7 @@
 #define DP_MAINLINK_FLUSH_MODE_UPDATE_SDP      
FIELD_PREP(DP_MAINLINK_CTRL_FLUSH_MODE_MASK, 1)
 #define DP_MAINLINK_FLUSH_MODE_SDE_PERIPH_UPDATE       
FIELD_PREP(DP_MAINLINK_CTRL_FLUSH_MODE_MASK, 3)
 #define DP_MAINLINK_FB_BOUNDARY_SEL            (0x02000000)
+#define DP_MAINLINK_CTRL_MST_EN                        (0x04000100)
 
 #define REG_DP_STATE_CTRL                      (0x00000004)
 #define DP_STATE_CTRL_LINK_TRAINING_PATTERN1   (0x00000001)

-- 
2.34.1