[PATCH v2] drm/i915/tgl: Implement TGL DisplayPort training sequence

José Roberto de Souza
2019-08-20T22:01:45Z

On TGL some registers moved from DDI to transcoder and the
DisplayPort training sequence has a separate BSpec page.

I started adding 'ifs' to the original intel_ddi_pre_enable_dp() but
it was becoming really hard to follow, so a new and cleaner function
for TGL was added with comments of all steps. It's similar to ICL, but
different enough to deserve a new function

The rest of DisplayPort enable and the whole disable sequences
remained the same.

v2: FEC and DSC should be enabled on sink side before start link
training(Maarten reported and Manasi confirmed the DSC part)

BSpec: 49190
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Manasi Navare <manasi.d.navare@intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: José Roberto de Souza <jose.souza@intel.com>
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
---
drivers/gpu/drm/i915/display/intel_ddi.c | 138 ++++++++++++++++++++++-
drivers/gpu/drm/i915/display/intel_dp.c | 8 +-
2 files changed, 138 insertions(+), 8 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_ddi.c b/drivers/gpu/drm/i915/display/intel_ddi.c
index 8eb2b3ec01ed..1c1534e2d833 100644
--- a/drivers/gpu/drm/i915/display/intel_ddi.c
+++ b/drivers/gpu/drm/i915/display/intel_ddi.c
@@ -1761,7 +1761,14 @@ void intel_ddi_set_vc_payload_alloc(const struct intel_crtc_state *crtc_state,
I915_WRITE(TRANS_DDI_FUNC_CTL(cpu_transcoder), temp);
}

-void intel_ddi_enable_transcoder_func(const struct intel_crtc_state *crtc_state)
+/*
+ * Returns the TRANS_DDI_FUNC_CTL value based on CRTC state.
+ *
+ * Only intended to be used by intel_ddi_enable_transcoder_func() and
+ * intel_ddi_config_transcoder_func().
+ */
+static u32
+intel_ddi_transcoder_func_reg_val_get(const struct intel_crtc_state *crtc_state)
{
struct intel_crtc *crtc = to_intel_crtc(crtc_state->base.crtc);
struct intel_encoder *encoder = intel_ddi_get_crtc_encoder(crtc);
@@ -1845,6 +1852,33 @@ void intel_ddi_enable_transcoder_func(const struct intel_crtc_state *crtc_state)
temp |= DDI_PORT_WIDTH(crtc_state->lane_count);
}

+ return temp;
+}
+
+void intel_ddi_enable_transcoder_func(const struct intel_crtc_state *crtc_state)
+{
+ struct intel_crtc *crtc = to_intel_crtc(crtc_state->base.crtc);
+ struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
+ enum transcoder cpu_transcoder = crtc_state->cpu_transcoder;
+ u32 temp;
+
+ temp = intel_ddi_transcoder_func_reg_val_get(crtc_state);
+ I915_WRITE(TRANS_DDI_FUNC_CTL(cpu_transcoder), temp);
+}
+
+/*
+ * Same as intel_ddi_enable_transcoder_func() but it do not set the enable bit
+ */
+static void
+intel_ddi_config_transcoder_func(const struct intel_crtc_state *crtc_state)
+{
+ struct intel_crtc *crtc = to_intel_crtc(crtc_state->base.crtc);
+ struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
+ enum transcoder cpu_transcoder = crtc_state->cpu_transcoder;
+ u32 temp;
+
+ temp = intel_ddi_transcoder_func_reg_val_get(crtc_state);
+ temp &= ~TRANS_DDI_FUNC_ENABLE;
I915_WRITE(TRANS_DDI_FUNC_CTL(cpu_transcoder), temp);
}

@@ -3160,9 +3194,93 @@ static void intel_ddi_disable_fec_state(struct intel_encoder *encoder,
POSTING_READ(DP_TP_CTL(port));
}

-static void intel_ddi_pre_enable_dp(struct intel_encoder *encoder,
- const struct intel_crtc_state *crtc_state,
- const struct drm_connector_state *conn_state)
+static void tgl_ddi_pre_enable_dp(struct intel_encoder *encoder,
+ const struct intel_crtc_state *crtc_state,
+ const struct drm_connector_state *conn_state)
+{
+ struct intel_dp *intel_dp = enc_to_intel_dp(&encoder->base);
+ struct drm_i915_private *dev_priv = to_i915(encoder->base.dev);
+ enum phy phy = intel_port_to_phy(dev_priv, encoder->port);
+ struct intel_digital_port *dig_port = enc_to_dig_port(&encoder->base);
+ bool is_mst = intel_crtc_has_type(crtc_state, INTEL_OUTPUT_DP_MST);
+ int level = intel_ddi_dp_level(intel_dp);
+
+ intel_dp_set_link_params(intel_dp, crtc_state->port_clock,
+ crtc_state->lane_count, is_mst);
+
+ /* 1.a got on intel_atomic_commit_tail() */
+
+ /* 2. */
+ intel_edp_panel_on(intel_dp);
+
+ /*
+ * 1.b, 3. and 4. is done by before this functions by
+ * haswell_crtc_enable()->intel_encoders_pre_pll_enable() and
+ * haswell_crtc_enable()->intel_enable_shared_dpll()
+ */
+
+ /* 5. */
+ if (!intel_phy_is_tc(dev_priv, phy) ||
+ dig_port->tc_mode != TC_PORT_TBT_ALT)
+ intel_display_power_get(dev_priv,
+ dig_port->ddi_io_power_domain);
+
+ /* 6. */
+ icl_program_mg_dp_mode(dig_port);
+
+ /*
+ * 7.a - Steps in this function that should only be executed over MST
+ * master as MST encoders will only be executed on MST master as MST
+ * encoder have have it's own pre_enable() hook
+ */
+ intel_ddi_enable_pipe_clock(crtc_state);
+
+ /* 7.b */
+ intel_ddi_config_transcoder_func(crtc_state);
+
+ /* 7.d */
+ icl_disable_phy_clock_gating(dig_port);
+
+ /* 7.e */
+ icl_ddi_vswing_sequence(encoder, crtc_state->port_clock, level,
+ encoder->type);
+
+ /* 7.f */
+ if (intel_phy_is_combo(dev_priv, phy)) {
+ bool lane_reversal =
+ dig_port->saved_port_bits & DDI_BUF_PORT_REVERSAL;
+
+ intel_combo_phy_power_up_lanes(dev_priv, phy, false,
+ crtc_state->lane_count,
+ lane_reversal);
+ }
+
+ /* 7.g */
+ intel_ddi_init_dp_buf_reg(encoder);
+
+ if (!is_mst)
+ intel_dp_sink_dpms(intel_dp, DRM_MODE_DPMS_ON);
+
+ intel_dp_sink_set_decompression_state(intel_dp, crtc_state, true);
+ /*
+ * DDI FEC: "anticipates enabling FEC encoding sets the FEC_READY bit
+ * in the FEC_CONFIGURATION register to 1 before initiating link
+ * training
+ */
+ intel_dp_sink_set_fec_ready(intel_dp, crtc_state);
+ /* 7.c, 7.h, 7.i, 7.j */
+ intel_dp_start_link_train(intel_dp);
+
+ /* 7.k */
+ intel_dp_stop_link_train(intel_dp);
+
+ /* 7.l */
+ intel_dsc_enable(encoder, crtc_state);
+}
+
+static void hsw_ddi_pre_enable_dp(struct intel_encoder *encoder,
+ const struct intel_crtc_state *crtc_state,
+ const struct drm_connector_state *conn_state)
{
struct intel_dp *intel_dp = enc_to_intel_dp(&encoder->base);
struct drm_i915_private *dev_priv = to_i915(encoder->base.dev);
@@ -3228,6 +3346,18 @@ static void intel_ddi_pre_enable_dp(struct intel_encoder *encoder,
intel_dsc_enable(encoder, crtc_state);
}

+static void intel_ddi_pre_enable_dp(struct intel_encoder *encoder,
+ const struct intel_crtc_state *crtc_state,
+ const struct drm_connector_state *conn_state)
+{
+ struct drm_i915_private *dev_priv = to_i915(encoder->base.dev);
+
+ if (INTEL_GEN(dev_priv) >= 12)
+ tgl_ddi_pre_enable_dp(encoder, crtc_state, conn_state);
+ else
+ hsw_ddi_pre_enable_dp(encoder, crtc_state, conn_state);
+}
+
static void intel_ddi_pre_enable_hdmi(struct intel_encoder *encoder,
const struct intel_crtc_state *crtc_state,
const struct drm_connector_state *conn_state)
diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
index 5c45a3bb102d..1a59c50f7e0a 100644
--- a/drivers/gpu/drm/i915/display/intel_dp.c
+++ b/drivers/gpu/drm/i915/display/intel_dp.c
@@ -3950,13 +3950,13 @@ void intel_dp_set_idle_link_train(struct intel_dp *intel_dp)
I915_WRITE(DP_TP_CTL(port), val);

/*
- * On PORT_A we can have only eDP in SST mode. There the only reason
- * we need to set idle transmission mode is to work around a HW issue
- * where we enable the pipe while not in idle link-training mode.
+ * Until TGL on PORT_A we can have only eDP in SST mode. There the only
+ * reason we need to set idle transmission mode is to work around a HW
+ * issue where we enable the pipe while not in idle link-training mode.
* In this case there is requirement to wait for a minimum number of
* idle patterns to be sent.
*/
- if (port == PORT_A)
+ if (port == PORT_A && INTEL_GEN(dev_priv) < 12)
return;

if (intel_de_wait_for_set(dev_priv, DP_TP_STATUS(port),
--
2.22.1