[Intel-gfx] [RFC 4/7] drm/i915: Add support for starting FRL training for HDMI2.1 via PCON
Ankit Nautiyal
ankit.k.nautiyal at intel.com
Fri Sep 25 12:13:37 UTC 2020
This patch adds functions to start FRL training for an HDMI2.1 sink,
connected via a PCON as a DP branch device.
This patch also adds a new structure for storing frl training related
data, when FRL training is completed.
Signed-off-by: Ankit Nautiyal <ankit.k.nautiyal at intel.com>
---
.../drm/i915/display/intel_display_types.h | 6 +
drivers/gpu/drm/i915/display/intel_dp.c | 202 ++++++++++++++++++
drivers/gpu/drm/i915/display/intel_dp.h | 2 +
3 files changed, 210 insertions(+)
diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h b/drivers/gpu/drm/i915/display/intel_display_types.h
index 3d4bf9b6a0a2..9a295a43b189 100644
--- a/drivers/gpu/drm/i915/display/intel_display_types.h
+++ b/drivers/gpu/drm/i915/display/intel_display_types.h
@@ -1264,6 +1264,11 @@ struct intel_dp_compliance {
u8 test_lane_count;
};
+struct intel_dp_pcon_frl {
+ bool is_trained;
+ int trained_rate_gbps;
+};
+
struct intel_dp {
i915_reg_t output_reg;
u32 DP;
@@ -1312,6 +1317,7 @@ struct intel_dp {
unsigned long last_backlight_off;
ktime_t panel_power_off_time;
+ struct intel_dp_pcon_frl frl;
struct notifier_block edp_notifier;
/*
diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
index bf1e9cf1c0f3..3a8e69e5bbfb 100644
--- a/drivers/gpu/drm/i915/display/intel_dp.c
+++ b/drivers/gpu/drm/i915/display/intel_dp.c
@@ -2869,6 +2869,9 @@ static void intel_dp_prepare(struct intel_encoder *encoder,
intel_dp->DP |= DP_PIPE_SEL_CHV(crtc->pipe);
else
intel_dp->DP |= DP_PIPE_SEL(crtc->pipe);
+
+ intel_dp->frl.is_trained = false;
+ intel_dp->frl.trained_rate_gbps = 0;
}
}
@@ -3705,6 +3708,9 @@ static void intel_disable_dp(struct intel_atomic_state *state,
intel_edp_backlight_off(old_conn_state);
intel_dp_sink_dpms(intel_dp, DRM_MODE_DPMS_OFF);
intel_edp_panel_off(intel_dp);
+
+ intel_dp->frl.is_trained = false;
+ intel_dp->frl.trained_rate_gbps = 0;
}
static void g4x_disable_dp(struct intel_atomic_state *state,
@@ -3799,6 +3805,202 @@ cpt_set_link_train(struct intel_dp *intel_dp,
intel_de_posting_read(dev_priv, intel_dp->output_reg);
}
+static int intel_dp_get_max_rate_gbps(struct intel_dp *intel_dp)
+{
+ int max_link_clock, max_lanes, max_rate_khz, max_rate_gbps;
+
+ max_link_clock = intel_dp_max_link_rate(intel_dp);
+ max_lanes = intel_dp_max_lane_count(intel_dp);
+ max_rate_khz = intel_dp_max_data_rate(max_link_clock, max_lanes);
+ max_rate_gbps = 8 * DIV_ROUND_UP(max_rate_khz, 1000000);
+
+ return max_rate_gbps;
+}
+
+static int intel_dp_pcon_get_frl_mask(u8 frl_bw_mask)
+{
+ int bw_gbps[] = {9, 18, 24, 32, 40, 48};
+ int i;
+
+ for (i = ARRAY_SIZE(bw_gbps) - 1; i >= 0; i--) {
+ if (frl_bw_mask & (1 << i))
+ return bw_gbps[i];
+ }
+ return 0;
+}
+
+static int intel_dp_pcon_set_frl_mask(int max_frl)
+{
+ int max_frl_mask = 0;
+
+ switch (max_frl) {
+ case 48:
+ max_frl_mask |= DP_PCON_FRL_BW_MASK_48GBPS;
+ break;
+ case 40:
+ max_frl_mask |= DP_PCON_FRL_BW_MASK_40GBPS;
+ break;
+ case 32:
+ max_frl_mask |= DP_PCON_FRL_BW_MASK_32GBPS;
+ break;
+ case 24:
+ max_frl_mask |= DP_PCON_FRL_BW_MASK_24GBPS;
+ break;
+ case 18:
+ max_frl_mask |= DP_PCON_FRL_BW_MASK_18GBPS;
+ break;
+ case 9:
+ max_frl_mask |= DP_PCON_FRL_BW_MASK_9GBPS;
+ break;
+ default:
+ max_frl_mask = 0;
+ }
+
+ return max_frl_mask;
+}
+
+static int intel_dp_hdmi_sink_max_frl(struct intel_dp *intel_dp)
+{
+ struct intel_connector *intel_connector = intel_dp->attached_connector;
+ struct drm_connector *connector = &intel_connector->base;
+
+ return (connector->display_info.hdmi.max_frl_rate_per_lane *
+ connector->display_info.hdmi.max_lane);
+}
+
+static int intel_dp_pcon_start_frl_training(struct intel_dp *intel_dp)
+{
+#define PCON_EXTENDED_TRAIN_MODE true
+#define PCON_CONCURRENT_MODE true
+#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
+
+ struct drm_i915_private *i915 = dp_to_i915(intel_dp);
+ int max_frl, max_pcon_frl, max_sink_frl, max_rate_gbps, max_frl_edid, ret;
+ u8 max_frl_mask = 0, frl_trained_mask;
+ bool is_active;
+
+ ret = drm_dp_pcon_reset_frl_config(&intel_dp->aux);
+ if (ret < 0)
+ return ret;
+
+ max_rate_gbps = intel_dp_get_max_rate_gbps(intel_dp);
+ drm_dbg(&i915->drm, "Source max rate = %d Gbps\n", max_rate_gbps);
+
+ max_pcon_frl = drm_dp_get_pcon_max_frl_bw(&intel_dp->aux,
+ intel_dp->dpcd,
+ intel_dp->downstream_ports);
+ drm_dbg(&i915->drm, "PCON max rate = %d Gbps\n", max_pcon_frl);
+
+ /* Double Check from HDMI SINK EDID */
+ max_frl_edid = intel_dp_hdmi_sink_max_frl(intel_dp);
+ drm_dbg(&i915->drm, "Sink max rate from EDID = %d Gbps\n", max_frl_edid);
+
+ max_sink_frl = drm_dp_get_hdmi_max_frl_bw(&intel_dp->aux);
+ drm_dbg(&i915->drm, "Sink max rate from PCON = %d Gbps\n", max_sink_frl);
+
+ /* TODO MAX SINK FRL from PCON is not enumerated. Using MAX FRL value
+ * directly from EDID. Need to confirm from Spec.
+ */
+ max_frl = min(max_rate_gbps, min(max_frl_edid, max_pcon_frl));
+
+ if (max_frl <= 0)
+ return -EINVAL;
+
+ ret = drm_dp_pcon_frl_prepare(&intel_dp->aux, false);
+ if (ret < 0)
+ return ret;
+ /* Wait for PCON to be FRL Ready */
+ wait_for(is_active = drm_dp_pcon_is_frl_ready(&intel_dp->aux) == true, TIMEOUT_FRL_READY_MS);
+
+ if (!is_active)
+ return -ETIMEDOUT;
+
+ max_frl_mask = intel_dp_pcon_set_frl_mask(max_frl);
+ ret = drm_dp_pcon_frl_configure_1(&intel_dp->aux, max_frl, PCON_SEQUENTIAL_MODE);
+ if (ret < 0)
+ return ret;
+ ret = drm_dp_pcon_frl_configure_2(&intel_dp->aux, max_frl_mask, PCON_NORMAL_TRAIN_MODE);
+ if (ret < 0)
+ return ret;
+ ret = drm_dp_pcon_frl_enable(&intel_dp->aux);
+ if (ret < 0)
+ return ret;
+ /*
+ * Wait for FRL to be completed
+ * Check if the HDMI Link is up and active.
+ */
+ wait_for(is_active = drm_dp_pcon_hdmi_link_active(&intel_dp->aux) == true, TIMEOUT_HDMI_LINK_ACTIVE_MS);
+
+ if (!is_active)
+ return -ETIMEDOUT;
+ /*
+ * Verify HDMI Link configuration shows FRL Mode.
+ */
+ if (DP_PCON_HDMI_MODE_FRL != drm_dp_pcon_hdmi_link_mode(&intel_dp->aux, &frl_trained_mask)) {
+ drm_dbg(&i915->drm, "HDMI couldn't be trained in FRL Mode\n");
+ return -EINVAL;
+ }
+ drm_dbg(&i915->drm, "MAX_FRL_MASK = %u, FRL_TRAINED_MASK = %u\n", max_frl_mask, frl_trained_mask);
+
+ /*
+ * Read HDMI_LINK_STATUS_TRAINED 0x2005 bit 5
+ * TODO: Details not mentioned in spec. Need to check.
+ */
+
+ intel_dp->frl.trained_rate_gbps = intel_dp_pcon_get_frl_mask(frl_trained_mask);
+ intel_dp->frl.is_trained = true;
+ drm_dbg(&i915->drm, "FRL trained with : %d Gbps\n", intel_dp->frl.trained_rate_gbps);
+
+ return 0;
+}
+
+static bool intel_dp_is_frl_required(struct intel_dp *intel_dp)
+{
+ if (!intel_dp->frl.is_trained)
+ return true;
+ /*
+ * #TODO check if the mode really required FRL or can work
+ * with TMDS mode.
+ */
+
+ return false;
+}
+
+static bool intel_dp_is_hdmi_2_1_sink(struct intel_dp *intel_dp)
+{
+ if (drm_dp_is_branch(intel_dp->dpcd) &&
+ intel_dp_hdmi_sink_max_frl(intel_dp) > 0)
+ return true;
+
+ return false;
+}
+
+void intel_dp_check_frl_training(struct intel_dp *intel_dp)
+{
+ struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);
+
+ if (!intel_dp_is_hdmi_2_1_sink(intel_dp) ||
+ !intel_dp_is_frl_required(intel_dp))
+ return;
+
+ if (intel_dp_pcon_start_frl_training(intel_dp) < 0) {
+ int ret, mode;
+
+ drm_dbg(&dev_priv->drm, "Couldnt set FRL mode, continuing with TMDS mode\n");
+ ret = drm_dp_pcon_reset_frl_config(&intel_dp->aux);
+ mode = drm_dp_pcon_hdmi_link_mode(&intel_dp->aux, NULL);
+
+ if (ret < 0 || mode != DP_PCON_HDMI_MODE_TMDS)
+ drm_dbg(&dev_priv->drm, "Issue with PCON, cannot set TMDS mode\n");
+ }
+
+ else
+ drm_dbg(&dev_priv->drm, "FRL training Completed\n");
+}
+
static void
g4x_set_link_train(struct intel_dp *intel_dp,
u8 dp_train_pat)
diff --git a/drivers/gpu/drm/i915/display/intel_dp.h b/drivers/gpu/drm/i915/display/intel_dp.h
index 08a1c0aa8b94..d67ef2945064 100644
--- a/drivers/gpu/drm/i915/display/intel_dp.h
+++ b/drivers/gpu/drm/i915/display/intel_dp.h
@@ -139,4 +139,6 @@ void intel_ddi_update_pipe(struct intel_atomic_state *state,
int intel_dp_init_hdcp(struct intel_digital_port *dig_port,
struct intel_connector *intel_connector);
+void intel_dp_check_frl_training(struct intel_dp *intel_dp);
+
#endif /* __INTEL_DP_H__ */
--
2.17.1
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