[Intel-gfx] [PATCH v2 3/4] drm/i915: Enable/disable TMDS output buffers in DP++ adaptor as needed

[ville.syrjala at linux.intel.com]

From: Ville Syrjälä <ville.syrjala at linux.intel.com>

To save a bit of power, let's try to turn off the TMDS output buffers
in DP++ adaptors when we're not driving the port.

v2: Let's not forget DDI, toss in a debug message while at it

Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
---
 drivers/gpu/drm/i915/intel_ddi.c  | 12 ++++++++++++
 drivers/gpu/drm/i915/intel_drv.h  |  2 ++
 drivers/gpu/drm/i915/intel_hdmi.c | 31 +++++++++++++++++++++++++++++--
 3 files changed, 43 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_ddi.c b/drivers/gpu/drm/i915/intel_ddi.c
index 21a9b83f3bfc..458c41788b80 100644
--- a/drivers/gpu/drm/i915/intel_ddi.c
+++ b/drivers/gpu/drm/i915/intel_ddi.c
@@ -2301,6 +2301,12 @@ static void intel_ddi_pre_enable(struct intel_encoder *intel_encoder)
 	enum port port = intel_ddi_get_encoder_port(intel_encoder);
 	int type = intel_encoder->type;
 
+	if (type == INTEL_OUTPUT_HDMI) {
+		struct intel_hdmi *intel_hdmi = enc_to_intel_hdmi(encoder);
+
+		intel_dp_dual_mode_set_tmds_output(intel_hdmi, true);
+	}
+
 	intel_prepare_ddi_buffer(intel_encoder);
 
 	if (type == INTEL_OUTPUT_EDP) {
@@ -2367,6 +2373,12 @@ static void intel_ddi_post_disable(struct intel_encoder *intel_encoder)
 					DPLL_CTRL2_DDI_CLK_OFF(port)));
 	else if (INTEL_INFO(dev)->gen < 9)
 		I915_WRITE(PORT_CLK_SEL(port), PORT_CLK_SEL_NONE);
+
+	if (type == INTEL_OUTPUT_HDMI) {
+		struct intel_hdmi *intel_hdmi = enc_to_intel_hdmi(encoder);
+
+		intel_dp_dual_mode_set_tmds_output(intel_hdmi, false);
+	}
 }
 
 static void intel_enable_ddi(struct intel_encoder *intel_encoder)
diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index 944eacbfb6a9..2e4fa4337c59 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -706,6 +706,7 @@ struct intel_hdmi {
 	int ddc_bus;
 	struct {
 		int max_tmds_clock;
+		bool tmds_output_control;
 	} dp_dual_mode;
 	bool limited_color_range;
 	bool color_range_auto;
@@ -1355,6 +1356,7 @@ void intel_hdmi_init_connector(struct intel_digital_port *intel_dig_port,
 struct intel_hdmi *enc_to_intel_hdmi(struct drm_encoder *encoder);
 bool intel_hdmi_compute_config(struct intel_encoder *encoder,
 			       struct intel_crtc_state *pipe_config);
+void intel_dp_dual_mode_set_tmds_output(struct intel_hdmi *hdmi, bool enable);
 
 
 /* intel_lvds.c */
diff --git a/drivers/gpu/drm/i915/intel_hdmi.c b/drivers/gpu/drm/i915/intel_hdmi.c
index 1e8cfdb18dc7..4b528a669f8e 100644
--- a/drivers/gpu/drm/i915/intel_hdmi.c
+++ b/drivers/gpu/drm/i915/intel_hdmi.c
@@ -837,6 +837,20 @@ static void hsw_set_infoframes(struct drm_encoder *encoder,
 	intel_hdmi_set_hdmi_infoframe(encoder, adjusted_mode);
 }
 
+void intel_dp_dual_mode_set_tmds_output(struct intel_hdmi *hdmi, bool enable)
+{
+	if (hdmi->dp_dual_mode.tmds_output_control) {
+		struct drm_i915_private *dev_priv = to_i915(intel_hdmi_to_dev(hdmi));
+		struct i2c_adapter *adapter =
+			intel_gmbus_get_adapter(dev_priv, hdmi->ddc_bus);
+
+		DRM_DEBUG_KMS("%s DP dual mode adaptor TMDS output\n",
+			      enable ? "Enabling" : "Disabling");
+
+		drm_dp_dual_mode_set_tmds_output(adapter, enable);
+	}
+}
+
 static void intel_hdmi_prepare(struct intel_encoder *encoder)
 {
 	struct drm_device *dev = encoder->base.dev;
@@ -846,6 +860,8 @@ static void intel_hdmi_prepare(struct intel_encoder *encoder)
 	const struct drm_display_mode *adjusted_mode = &crtc->config->base.adjusted_mode;
 	u32 hdmi_val;
 
+	intel_dp_dual_mode_set_tmds_output(intel_hdmi, true);
+
 	hdmi_val = SDVO_ENCODING_HDMI;
 	if (!HAS_PCH_SPLIT(dev) && crtc->config->limited_color_range)
 		hdmi_val |= HDMI_COLOR_RANGE_16_235;
@@ -1144,6 +1160,8 @@ static void intel_disable_hdmi(struct intel_encoder *encoder)
 	}
 
 	intel_hdmi->set_infoframes(&encoder->base, false, NULL);
+
+	intel_dp_dual_mode_set_tmds_output(intel_hdmi, false);
 }
 
 static void g4x_disable_hdmi(struct intel_encoder *encoder)
@@ -1369,6 +1387,7 @@ intel_hdmi_unset_edid(struct drm_connector *connector)
 	intel_hdmi->rgb_quant_range_selectable = false;
 
 	intel_hdmi->dp_dual_mode.max_tmds_clock = 0;
+	intel_hdmi->dp_dual_mode.tmds_output_control = false;
 
 	kfree(to_intel_connector(connector)->detect_edid);
 	to_intel_connector(connector)->detect_edid = NULL;
@@ -1392,15 +1411,23 @@ intel_hdmi_dp_dual_mode_detect(struct drm_connector *connector)
 	 */
 	if (type == DRM_DP_DUAL_MODE_TYPE2_DVI ||
 	    type == DRM_DP_DUAL_MODE_TYPE2_HDMI) {
+		bool tmds_enabled;
+
 		hdmi->dp_dual_mode.max_tmds_clock =
 			drm_dp_dual_mode_max_tmds_clock(adapter);
+
+		hdmi->dp_dual_mode.tmds_output_control =
+			drm_dp_dual_mode_get_tmds_output(adapter, &tmds_enabled) == 0 &&
+			drm_dp_dual_mode_set_tmds_output(adapter, tmds_enabled) == 0;
 	} else {
 		hdmi->dp_dual_mode.max_tmds_clock = 165000;
+		hdmi->dp_dual_mode.tmds_output_control = false;
 	}
 
-	DRM_DEBUG_KMS("DP dual mode adaptor (%s) detected (max TMDS clock: %d kHz)\n",
+	DRM_DEBUG_KMS("DP dual mode adaptor (%s) detected (max TMDS clock: %d kHz, TMDS OE# control: %s)\n",
 		      drm_dp_get_dual_mode_type_name(type),
-		      hdmi->dp_dual_mode.max_tmds_clock);
+		      hdmi->dp_dual_mode.max_tmds_clock,
+		      yesno(hdmi->dp_dual_mode.tmds_output_control));
 }
 
 static bool
-- 
2.4.10