drm/dp_helper: Define options for FRL training for HDMI2.1 PCON

Currently the FRL training mode (Concurrent, Sequential) and
training type (Normal, Extended) are not defined properly and
are passed as bool values in drm_helpers for pcon
configuration for FRL training.

This patch:
-Add register masks for Sequential and Normal FRL training options.
-Fixes the drm_helpers for FRL Training configuration to use the
 appropriate masks.
-Modifies the calls to the above drm_helpers in i915/intel_dp as per
 the above change.

v2: Re-used the register masks for these options, instead of enum. (Ville)
Signed-off-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Acked-by: Maxime Ripard <mripard@kernel.org>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210323112422.1211-2-ankit.k.nautiyal@intel.com

drivers/gpu/drm/drm_dp_helper.c

@@ -2635,14 +2635,16 @@ EXPORT_SYMBOL(drm_dp_pcon_is_frl_ready);
  * drm_dp_pcon_frl_configure_1() - Set HDMI LINK Configuration-Step1
  * @aux: DisplayPort AUX channel
  * @max_frl_gbps: maximum frl bw to be configured between PCON and HDMI sink
- * @concurrent_mode: true if concurrent mode or operation is required,
- * false otherwise.
+ * @frl_mode: FRL Training mode, it can be either Concurrent or Sequential.
+ * In Concurrent Mode, the FRL link bring up can be done along with
+ * DP Link training. In Sequential mode, the FRL link bring up is done prior to
+ * the DP Link training.
  *
  * Returns 0 if success, else returns negative error code.
  */
 
 int drm_dp_pcon_frl_configure_1(struct drm_dp_aux *aux, int max_frl_gbps,
-				bool concurrent_mode)
+				u8 frl_mode)
 {
 	int ret;
 	u8 buf;
@@ -2651,7 +2653,7 @@ int drm_dp_pcon_frl_configure_1(struct drm_dp_aux *aux, int max_frl_gbps,
 	if (ret < 0)
 		return ret;
 
-	if (concurrent_mode)
+	if (frl_mode == DP_PCON_ENABLE_CONCURRENT_LINK)
 		buf |= DP_PCON_ENABLE_CONCURRENT_LINK;
 	else
 		buf &= ~DP_PCON_ENABLE_CONCURRENT_LINK;
@@ -2694,21 +2696,23 @@ EXPORT_SYMBOL(drm_dp_pcon_frl_configure_1);
  * drm_dp_pcon_frl_configure_2() - Set HDMI Link configuration Step-2
  * @aux: DisplayPort AUX channel
  * @max_frl_mask : Max FRL BW to be tried by the PCON with HDMI Sink
- * @extended_train_mode : true for Extended Mode, false for Normal Mode.
- * In Normal mode, the PCON tries each frl bw from the max_frl_mask starting
- * from min, and stops when link training is successful. In Extended mode, all
- * frl bw selected in the mask are trained by the PCON.
+ * @frl_type : FRL training type, can be Extended, or Normal.
+ * In Normal FRL training, the PCON tries each frl bw from the max_frl_mask
+ * starting from min, and stops when link training is successful. In Extended
+ * FRL training, all frl bw selected in the mask are trained by the PCON.
  *
  * Returns 0 if success, else returns negative error code.
  */
 int drm_dp_pcon_frl_configure_2(struct drm_dp_aux *aux, int max_frl_mask,
-				bool extended_train_mode)
+				u8 frl_type)
 {
 	int ret;
 	u8 buf = max_frl_mask;
 
-	if (extended_train_mode)
+	if (frl_type == DP_PCON_FRL_LINK_TRAIN_EXTENDED)
 		buf |= DP_PCON_FRL_LINK_TRAIN_EXTENDED;
+	else
+		buf &= ~DP_PCON_FRL_LINK_TRAIN_EXTENDED;
 
 	ret = drm_dp_dpcd_writeb(aux, DP_PCON_HDMI_LINK_CONFIG_2, buf);
 	if (ret < 0)

drivers/gpu/drm/i915/display/intel_dp.c

@@ -2073,10 +2073,6 @@ static int intel_dp_hdmi_sink_max_frl(struct intel_dp *intel_dp)
 
 static int intel_dp_pcon_start_frl_training(struct intel_dp *intel_dp)
 {
-#define PCON_EXTENDED_TRAIN_MODE (1 > 0)
-#define PCON_CONCURRENT_MODE (1 > 0)
-#define PCON_SEQUENTIAL_MODE !PCON_CONCURRENT_MODE
-#define PCON_NORMAL_TRAIN_MODE !PCON_EXTENDED_TRAIN_MODE
 #define TIMEOUT_FRL_READY_MS 500
 #define TIMEOUT_HDMI_LINK_ACTIVE_MS 1000
 
@@ -2110,10 +2106,12 @@ static int intel_dp_pcon_start_frl_training(struct intel_dp *intel_dp)
 		return -ETIMEDOUT;
 
 	max_frl_bw_mask = intel_dp_pcon_set_frl_mask(max_frl_bw);
-	ret = drm_dp_pcon_frl_configure_1(&intel_dp->aux, max_frl_bw, PCON_SEQUENTIAL_MODE);
+	ret = drm_dp_pcon_frl_configure_1(&intel_dp->aux, max_frl_bw,
+					  DP_PCON_ENABLE_SEQUENTIAL_LINK);
 	if (ret < 0)
 		return ret;
-	ret = drm_dp_pcon_frl_configure_2(&intel_dp->aux, max_frl_bw_mask, PCON_NORMAL_TRAIN_MODE);
+	ret = drm_dp_pcon_frl_configure_2(&intel_dp->aux, max_frl_bw_mask,
+					  DP_PCON_FRL_LINK_TRAIN_NORMAL);
 	if (ret < 0)
 		return ret;
 	ret = drm_dp_pcon_frl_enable(&intel_dp->aux);

include/drm/drm_dp_helper.h

@@ -1176,6 +1176,7 @@ struct drm_device;
 # define DP_PCON_ENABLE_MAX_BW_48GBPS	       6
 # define DP_PCON_ENABLE_SOURCE_CTL_MODE       (1 << 3)
 # define DP_PCON_ENABLE_CONCURRENT_LINK       (1 << 4)
+# define DP_PCON_ENABLE_SEQUENTIAL_LINK       (0 << 4)
 # define DP_PCON_ENABLE_LINK_FRL_MODE         (1 << 5)
 # define DP_PCON_ENABLE_HPD_READY	      (1 << 6)
 # define DP_PCON_ENABLE_HDMI_LINK             (1 << 7)
@@ -1190,6 +1191,7 @@ struct drm_device;
 # define DP_PCON_FRL_BW_MASK_40GBPS           (1 << 4)
 # define DP_PCON_FRL_BW_MASK_48GBPS           (1 << 5)
 # define DP_PCON_FRL_LINK_TRAIN_EXTENDED      (1 << 6)
+# define DP_PCON_FRL_LINK_TRAIN_NORMAL        (0 << 6)
 
 /* PCON HDMI LINK STATUS */
 #define DP_PCON_HDMI_TX_LINK_STATUS           0x303B
@@ -2154,9 +2156,9 @@ int drm_dp_get_pcon_max_frl_bw(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
 int drm_dp_pcon_frl_prepare(struct drm_dp_aux *aux, bool enable_frl_ready_hpd);
 bool drm_dp_pcon_is_frl_ready(struct drm_dp_aux *aux);
 int drm_dp_pcon_frl_configure_1(struct drm_dp_aux *aux, int max_frl_gbps,
-				bool concurrent_mode);
+				u8 frl_mode);
 int drm_dp_pcon_frl_configure_2(struct drm_dp_aux *aux, int max_frl_mask,
-				bool extended_train_mode);
+				u8 frl_type);
 int drm_dp_pcon_reset_frl_config(struct drm_dp_aux *aux);
 int drm_dp_pcon_frl_enable(struct drm_dp_aux *aux);