drm/i915: hdmi: add CEC notifier to intel_hdmi

This patchs adds the cec_notifier feature to the intel_hdmi part
of the i915 DRM driver. It uses the HDMI DRM connector name to differentiate
between each HDMI ports.
The changes will allow the i915 HDMI code to notify EDID and HPD changes
to an eventual CEC adapter.

Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Reviewed-by: Hans Verkuil <hans.verkuil@cisco.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Acked-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

drivers/gpu/drm/i915/Kconfig

@@ -23,6 +23,7 @@ config DRM_I915
 	select SYNC_FILE
 	select IOSF_MBI
 	select CRC32
+	select CEC_CORE if CEC_NOTIFIER
 	help
 	  Choose this option if you have a system that has "Intel Graphics
 	  Media Accelerator" or "HD Graphics" integrated graphics,

drivers/gpu/drm/i915/intel_display.h

@@ -126,6 +126,30 @@ enum port {
 
 #define port_name(p) ((p) + 'A')
 
+/*
+ * Ports identifier referenced from other drivers.
+ * Expected to remain stable over time
+ */
+static inline const char *port_identifier(enum port port)
+{
+	switch (port) {
+	case PORT_A:
+		return "Port A";
+	case PORT_B:
+		return "Port B";
+	case PORT_C:
+		return "Port C";
+	case PORT_D:
+		return "Port D";
+	case PORT_E:
+		return "Port E";
+	case PORT_F:
+		return "Port F";
+	default:
+		return "<invalid>";
+	}
+}
+
 enum dpio_channel {
 	DPIO_CH0,
 	DPIO_CH1

drivers/gpu/drm/i915/intel_drv.h

@@ -39,6 +39,7 @@
 #include <drm/drm_dp_mst_helper.h>
 #include <drm/drm_rect.h>
 #include <drm/drm_atomic.h>
+#include <media/cec-notifier.h>
 
 /**
  * __wait_for - magic wait macro
@@ -1017,6 +1018,7 @@ struct intel_hdmi {
 	bool has_audio;
 	bool rgb_quant_range_selectable;
 	struct intel_connector *attached_connector;
+	struct cec_notifier *cec_notifier;
 };
 
 struct intel_dp_mst_encoder;

drivers/gpu/drm/i915/intel_hdmi.c

@@ -1868,6 +1868,8 @@ intel_hdmi_set_edid(struct drm_connector *connector)
 		connected = true;
 	}
 
+	cec_notifier_set_phys_addr_from_edid(intel_hdmi->cec_notifier, edid);
+
 	return connected;
 }
 
@@ -1876,6 +1878,7 @@ intel_hdmi_detect(struct drm_connector *connector, bool force)
 {
 	enum drm_connector_status status;
 	struct drm_i915_private *dev_priv = to_i915(connector->dev);
+	struct intel_hdmi *intel_hdmi = intel_attached_hdmi(connector);
 
 	DRM_DEBUG_KMS("[CONNECTOR:%d:%s]\n",
 		      connector->base.id, connector->name);
@@ -1891,6 +1894,9 @@ intel_hdmi_detect(struct drm_connector *connector, bool force)
 
 	intel_display_power_put(dev_priv, POWER_DOMAIN_GMBUS);
 
+	if (status != connector_status_connected)
+		cec_notifier_phys_addr_invalidate(intel_hdmi->cec_notifier);
+
 	return status;
 }
 
@@ -2031,6 +2037,8 @@ static void chv_hdmi_pre_enable(struct intel_encoder *encoder,
 
 static void intel_hdmi_destroy(struct drm_connector *connector)
 {
+	if (intel_attached_hdmi(connector)->cec_notifier)
+		cec_notifier_put(intel_attached_hdmi(connector)->cec_notifier);
 	kfree(to_intel_connector(connector)->detect_edid);
 	drm_connector_cleanup(connector);
 	kfree(connector);
@@ -2350,6 +2358,11 @@ void intel_hdmi_init_connector(struct intel_digital_port *intel_dig_port,
 		u32 temp = I915_READ(PEG_BAND_GAP_DATA);
 		I915_WRITE(PEG_BAND_GAP_DATA, (temp & ~0xf) | 0xd);
 	}
+
+	intel_hdmi->cec_notifier = cec_notifier_get_conn(dev->dev,
+							 port_identifier(port));
+	if (!intel_hdmi->cec_notifier)
+		DRM_DEBUG_KMS("CEC notifier get failed\n");
 }
 
 void intel_hdmi_init(struct drm_i915_private *dev_priv,