Re: [PATCH] drm/msm/dsi/phy: fix 7nm v4.0 settings for C-PHY mode

[Abhinav Kumar]

On 2/16/2022 4:08 PM, Dmitry Baryshkov wrote:

The dsi_7nm_phy_enable() disagrees with downstream for
glbl_str_swi_cal_sel_ctrl and glbl_hstx_str_ctrl_0 values. Update
programmed settings to match downstream driver. To remove the
possibility for such errors in future drop less_than_1500_mhz
assignment and specify settings explicitly.

Fixes: 5ac178381d26 ("drm/msm/dsi: support CPHY mode for 7nm pll/phy")
Signed-off-by: Dmitry Baryshkov <dmitry.barysh...@linaro.org>

Yes, this matches what we have downstream
Reviewed-by: Abhinav Kumar <quic_abhin...@quicinc.com>

---
  drivers/gpu/drm/msm/dsi/phy/dsi_phy_7nm.c | 22 ++++++++++++++--------
  1 file changed, 14 insertions(+), 8 deletions(-)

diff --git a/drivers/gpu/drm/msm/dsi/phy/dsi_phy_7nm.c 
b/drivers/gpu/drm/msm/dsi/phy/dsi_phy_7nm.c
index 36eb6109cb88..6e506feb111f 100644
--- a/drivers/gpu/drm/msm/dsi/phy/dsi_phy_7nm.c
+++ b/drivers/gpu/drm/msm/dsi/phy/dsi_phy_7nm.c
@@ -864,20 +864,26 @@ static int dsi_7nm_phy_enable(struct msm_dsi_phy *phy,
        /* Alter PHY configurations if data rate less than 1.5GHZ*/
        less_than_1500_mhz = (clk_req->bitclk_rate <= 1500000000);

- /* For C-PHY, no low power settings for lower clk rate */

-       if (phy->cphy_mode)
-               less_than_1500_mhz = false;
-
        if (phy->cfg->quirks & DSI_PHY_7NM_QUIRK_V4_1) {
                vreg_ctrl_0 = less_than_1500_mhz ? 0x53 : 0x52;
-               glbl_rescode_top_ctrl = less_than_1500_mhz ? 0x3d :  0x00;
-               glbl_rescode_bot_ctrl = less_than_1500_mhz ? 0x39 :  0x3c;
+               if (phy->cphy_mode) {
+                       glbl_rescode_top_ctrl = 0x00;
+                       glbl_rescode_bot_ctrl = 0x3c;
+               } else {
+                       glbl_rescode_top_ctrl = less_than_1500_mhz ? 0x3d :  
0x00;
+                       glbl_rescode_bot_ctrl = less_than_1500_mhz ? 0x39 :  
0x3c;
+               }
                glbl_str_swi_cal_sel_ctrl = 0x00;
                glbl_hstx_str_ctrl_0 = 0x88;
        } else {
                vreg_ctrl_0 = less_than_1500_mhz ? 0x5B : 0x59;
-               glbl_str_swi_cal_sel_ctrl = less_than_1500_mhz ? 0x03 : 0x00;
-               glbl_hstx_str_ctrl_0 = less_than_1500_mhz ? 0x66 : 0x88;
+               if (phy->cphy_mode) {
+                       glbl_str_swi_cal_sel_ctrl = 0x03;
+                       glbl_hstx_str_ctrl_0 = 0x66;
+               } else {
+                       glbl_str_swi_cal_sel_ctrl = less_than_1500_mhz ? 0x03 : 
0x00;
+                       glbl_hstx_str_ctrl_0 = less_than_1500_mhz ? 0x66 : 0x88;
+               }
                glbl_rescode_top_ctrl = 0x03;
                glbl_rescode_bot_ctrl = 0x3c;
        }