drm/tegra: sor: Use DP link training helpers

Make use of the DP link training helpers to implement full and fast link
training. While at it, refactor some of the code and remove various code
sequences that are not necessary.
Signed-off-by: Thierry Reding <treding@nvidia.com>

drivers/gpu/drm/tegra/dpaux.c

@@ -821,72 +821,3 @@ int drm_dp_aux_disable(struct drm_dp_aux *aux)
 
 	return 0;
 }
-
-int drm_dp_aux_prepare(struct drm_dp_aux *aux, u8 encoding)
-{
-	int err;
-
-	err = drm_dp_dpcd_writeb(aux, DP_MAIN_LINK_CHANNEL_CODING_SET,
-				 encoding);
-	if (err < 0)
-		return err;
-
-	return 0;
-}
-
-int drm_dp_aux_train(struct drm_dp_aux *aux, struct drm_dp_link *link,
-		     u8 pattern)
-{
-	u8 tp = pattern & DP_TRAINING_PATTERN_MASK;
-	u8 status[DP_LINK_STATUS_SIZE], values[4];
-	unsigned int i;
-	int err;
-
-	err = drm_dp_dpcd_writeb(aux, DP_TRAINING_PATTERN_SET, pattern);
-	if (err < 0)
-		return err;
-
-	if (tp == DP_TRAINING_PATTERN_DISABLE)
-		return 0;
-
-	for (i = 0; i < link->lanes; i++)
-		values[i] = DP_TRAIN_MAX_PRE_EMPHASIS_REACHED |
-			    DP_TRAIN_PRE_EMPH_LEVEL_0 |
-			    DP_TRAIN_MAX_SWING_REACHED |
-			    DP_TRAIN_VOLTAGE_SWING_LEVEL_0;
-
-	err = drm_dp_dpcd_write(aux, DP_TRAINING_LANE0_SET, values,
-				link->lanes);
-	if (err < 0)
-		return err;
-
-	usleep_range(500, 1000);
-
-	err = drm_dp_dpcd_read_link_status(aux, status);
-	if (err < 0)
-		return err;
-
-	switch (tp) {
-	case DP_TRAINING_PATTERN_1:
-		if (!drm_dp_clock_recovery_ok(status, link->lanes))
-			return -EAGAIN;
-
-		break;
-
-	case DP_TRAINING_PATTERN_2:
-		if (!drm_dp_channel_eq_ok(status, link->lanes))
-			return -EAGAIN;
-
-		break;
-
-	default:
-		dev_err(aux->dev, "unsupported training pattern %u\n", tp);
-		return -EINVAL;
-	}
-
-	err = drm_dp_dpcd_writeb(aux, DP_EDP_CONFIGURATION_SET, 0);
-	if (err < 0)
-		return err;
-
-	return 0;
-}

drivers/gpu/drm/tegra/drm.h

@@ -153,17 +153,12 @@ void tegra_output_connector_destroy(struct drm_connector *connector);
 void tegra_output_encoder_destroy(struct drm_encoder *encoder);
 
 /* from dpaux.c */
-struct drm_dp_link;
-
 struct drm_dp_aux *drm_dp_aux_find_by_of_node(struct device_node *np);
 enum drm_connector_status drm_dp_aux_detect(struct drm_dp_aux *aux);
 int drm_dp_aux_attach(struct drm_dp_aux *aux, struct tegra_output *output);
 int drm_dp_aux_detach(struct drm_dp_aux *aux);
 int drm_dp_aux_enable(struct drm_dp_aux *aux);
 int drm_dp_aux_disable(struct drm_dp_aux *aux);
-int drm_dp_aux_prepare(struct drm_dp_aux *aux, u8 encoding);
-int drm_dp_aux_train(struct drm_dp_aux *aux, struct drm_dp_link *link,
-		     u8 pattern);
 
 /* from fb.c */
 struct tegra_bo *tegra_fb_get_plane(struct drm_framebuffer *framebuffer,

drivers/gpu/drm/tegra/sor.h

@@ -283,10 +283,12 @@
 #define  SOR_DP_PADCTL_CM_TXD_2		(1 << 6)
 #define  SOR_DP_PADCTL_CM_TXD_1		(1 << 5)
 #define  SOR_DP_PADCTL_CM_TXD_0		(1 << 4)
+#define  SOR_DP_PADCTL_CM_TXD(x)	(1 << (4 + (x)))
 #define  SOR_DP_PADCTL_PD_TXD_3		(1 << 3)
 #define  SOR_DP_PADCTL_PD_TXD_0		(1 << 2)
 #define  SOR_DP_PADCTL_PD_TXD_1		(1 << 1)
 #define  SOR_DP_PADCTL_PD_TXD_2		(1 << 0)
+#define  SOR_DP_PADCTL_PD_TXD(x)	(1 << (0 + (x)))
 
 #define SOR_DP_PADCTL1 0x5d