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.
v2: As suggested by Uma Shankar: -renamed couple of variables for better clarity -tweaked the macros used for correct semantics for true/false -fixed other styling issues.
Signed-off-by: Ankit Nautiyal ankit.k.nautiyal@intel.com --- .../drm/i915/display/intel_display_types.h | 7 + drivers/gpu/drm/i915/display/intel_dp.c | 189 ++++++++++++++++++ drivers/gpu/drm/i915/display/intel_dp.h | 2 + 3 files changed, 198 insertions(+)
diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h b/drivers/gpu/drm/i915/display/intel_display_types.h index 282c6ee76384..2c58d63928b8 100644 --- a/drivers/gpu/drm/i915/display/intel_display_types.h +++ b/drivers/gpu/drm/i915/display/intel_display_types.h @@ -1286,6 +1286,11 @@ 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; @@ -1407,6 +1412,8 @@ struct intel_dp {
bool hobl_failed; bool hobl_active; + + struct intel_dp_pcon_frl frl; };
enum lspcon_vendor { diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c index caf7666f1892..7feee2adf9b2 100644 --- a/drivers/gpu/drm/i915/display/intel_dp.c +++ b/drivers/gpu/drm/i915/display/intel_dp.c @@ -2871,6 +2871,9 @@ 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; } }
@@ -3769,6 +3772,8 @@ static void intel_disable_dp(struct intel_atomic_state *state, intel_edp_backlight_off(old_conn_state); intel_dp_set_power(intel_dp, DP_SET_POWER_D3); 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, @@ -3864,6 +3869,190 @@ 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) +{ + + switch (max_frl) { + case 48: + return DP_PCON_FRL_BW_MASK_48GBPS; + case 40: + return DP_PCON_FRL_BW_MASK_40GBPS; + case 32: + return DP_PCON_FRL_BW_MASK_32GBPS; + case 24: + return DP_PCON_FRL_BW_MASK_24GBPS; + case 18: + return DP_PCON_FRL_BW_MASK_18GBPS; + case 9: + return DP_PCON_FRL_BW_MASK_9GBPS; + } + + return 0; +} + +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_lanes); +} + +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 + + struct drm_i915_private *i915 = dp_to_i915(intel_dp); + int max_frl_bw, max_pcon_frl_bw, max_sink_frl_bw, max_rate_gbps, max_edid_frl_bw, ret; + u8 max_frl_bw_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_bw = intel_dp->dfp.pcon_max_frl_bw; + drm_dbg(&i915->drm, "PCON max rate = %d Gbps\n", max_pcon_frl_bw); + + /* Double Check from HDMI SINK EDID */ + max_edid_frl_bw = intel_dp_hdmi_sink_max_frl(intel_dp); + drm_dbg(&i915->drm, "Sink max rate from EDID = %d Gbps\n", max_edid_frl_bw); + + max_sink_frl_bw = intel_dp->dfp.sink_max_frl_bw; + drm_dbg(&i915->drm, "Sink max rate from PCON = %d Gbps\n", max_sink_frl_bw); + + /* + * TODO MAX SINK FRL from PCON is not enumerated. Using MAX FRL value + * directly from EDID. Need to confirm from Spec. + */ + max_frl_bw = min(max_rate_gbps, min(max_edid_frl_bw, max_pcon_frl_bw)); + + if (max_frl_bw <= 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_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); + if (ret < 0) + return ret; + ret = drm_dp_pcon_frl_configure_2(&intel_dp->aux, max_frl_bw_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_bw_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, const struct intel_crtc_state *crtc_state, diff --git a/drivers/gpu/drm/i915/display/intel_dp.h b/drivers/gpu/drm/i915/display/intel_dp.h index 3f862b4fd34f..a667d3f578d6 100644 --- a/drivers/gpu/drm/i915/display/intel_dp.h +++ b/drivers/gpu/drm/i915/display/intel_dp.h @@ -143,4 +143,6 @@ bool intel_dp_initial_fastset_check(struct intel_encoder *encoder, void intel_dp_sync_state(struct intel_encoder *encoder, const struct intel_crtc_state *crtc_state);
+void intel_dp_check_frl_training(struct intel_dp *intel_dp); + #endif /* __INTEL_DP_H__ */