drm/bridge: analogix-anx78xx: Avoid drm_dp_link helpers

During the discussion of patches that enhance the drm_dp_link helpers it
was concluded that these helpers aren't very useful to begin with. Start
pushing the equivalent code into individual drivers to ultimately remove
them.

v4: use bulk DPCD writes if possible (Daniel Vetter)

Signed-off-by: Thierry Reding <treding@nvidia.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20191022145211.2258525-1-thierry.reding@gmail.com

diff --git a/drivers/gpu/drm/bridge/analogix-anx78xx.c b/drivers/gpu/drm/bridge/analogix-anx78xx.c
index 9ddc1f3cf841e5cdb6f86e70d12905e4376310a5..274989f96a9167643a24532b7d9b777cd4b8c3df 100644 (file)
--- a/drivers/gpu/drm/bridge/analogix-anx78xx.c
+++ b/drivers/gpu/drm/bridge/analogix-anx78xx.c
@@ -71,7 +71,6 @@ struct anx78xx {
        struct i2c_client *client;
        struct edid *edid;
        struct drm_connector connector;
-       struct drm_dp_link link;
        struct anx78xx_platform_data pdata;
        struct mutex lock;
 
@@ -748,7 +747,7 @@ static int anx78xx_init_pdata(struct anx78xx *anx78xx)
 
 static int anx78xx_dp_link_training(struct anx78xx *anx78xx)
 {
-       u8 dp_bw, value;
+       u8 dp_bw, dpcd[2];
        int err;
 
        err = regmap_write(anx78xx->map[I2C_IDX_RX_P0], SP_HDMI_MUTE_CTRL_REG,
@@ -801,18 +800,34 @@ static int anx78xx_dp_link_training(struct anx78xx *anx78xx)
        if (err)
                return err;
 
-       /* Check link capabilities */
-       err = drm_dp_link_probe(&anx78xx->aux, &anx78xx->link);
-       if (err < 0) {
-               DRM_ERROR("Failed to probe link capabilities: %d\n", err);
-               return err;
-       }
+       /*
+        * Power up the sink (DP_SET_POWER register is only available on DPCD
+        * v1.1 and later).
+        */
+       if (anx78xx->dpcd[DP_DPCD_REV] >= 0x11) {
+               err = drm_dp_dpcd_readb(&anx78xx->aux, DP_SET_POWER, &dpcd[0]);
+               if (err < 0) {
+                       DRM_ERROR("Failed to read DP_SET_POWER register: %d\n",
+                                 err);
+                       return err;
+               }
 
-       /* Power up the sink */
-       err = drm_dp_link_power_up(&anx78xx->aux, &anx78xx->link);
-       if (err < 0) {
-               DRM_ERROR("Failed to power up DisplayPort link: %d\n", err);
-               return err;
+               dpcd[0] &= ~DP_SET_POWER_MASK;
+               dpcd[0] |= DP_SET_POWER_D0;
+
+               err = drm_dp_dpcd_writeb(&anx78xx->aux, DP_SET_POWER, dpcd[0]);
+               if (err < 0) {
+                       DRM_ERROR("Failed to power up DisplayPort link: %d\n",
+                                 err);
+                       return err;
+               }
+
+               /*
+                * According to the DP 1.1 specification, a "Sink Device must
+                * exit the power saving state within 1 ms" (Section 2.5.3.1,
+                * Table 5-52, "Sink Control Field" (register 0x600).
+                */
+               usleep_range(1000, 2000);
        }
 
        /* Possibly enable downspread on the sink */
@@ -851,15 +866,22 @@ static int anx78xx_dp_link_training(struct anx78xx *anx78xx)
        if (err)
                return err;
 
-       value = drm_dp_link_rate_to_bw_code(anx78xx->link.rate);
+       dpcd[0] = drm_dp_max_link_rate(anx78xx->dpcd);
+       dpcd[0] = drm_dp_link_rate_to_bw_code(dpcd[0]);
        err = regmap_write(anx78xx->map[I2C_IDX_TX_P0],
-                          SP_DP_MAIN_LINK_BW_SET_REG, value);
+                          SP_DP_MAIN_LINK_BW_SET_REG, dpcd[0]);
        if (err)
                return err;
 
-       err = drm_dp_link_configure(&anx78xx->aux, &anx78xx->link);
+       dpcd[1] = drm_dp_max_lane_count(anx78xx->dpcd);
+
+       if (drm_dp_enhanced_frame_cap(anx78xx->dpcd))
+               dpcd[1] |= DP_LANE_COUNT_ENHANCED_FRAME_EN;
+
+       err = drm_dp_dpcd_write(&anx78xx->aux, DP_LINK_BW_SET, dpcd,
+                               sizeof(dpcd));
        if (err < 0) {
-               DRM_ERROR("Failed to configure DisplayPort link: %d\n", err);
+               DRM_ERROR("Failed to configure link: %d\n", err);
                return err;
        }