[PATCHv2 3/3] drm/i915: add DisplayPort CEC-Tunneling-over-AUX support

[Hans Verkuil <hverkuil@xs4all.nl>]

From: Hans Verkuil <hans.verkuil@cisco.com>

Implement support for this DisplayPort feature.

The cec device is created whenever it detects an adapter that
has this feature. It is only removed when a new adapter is connected
that does not support this. If a new adapter is connected that has
different properties than the previous one, then the old cec device is
unregistered and a new one is registered to replace the old one.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
---
 drivers/gpu/drm/i915/intel_dp.c | 18 ++++++++++++++----
 1 file changed, 14 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index 64fa774c855b..fdb853d2c458 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -32,6 +32,7 @@
 #include <linux/notifier.h>
 #include <linux/reboot.h>
 #include <asm/byteorder.h>
+#include <media/cec.h>
 #include <drm/drmP.h>
 #include <drm/drm_atomic_helper.h>
 #include <drm/drm_crtc.h>
@@ -1449,6 +1450,7 @@ static void intel_aux_reg_init(struct intel_dp *intel_dp)
 static void
 intel_dp_aux_fini(struct intel_dp *intel_dp)
 {
+	cec_unregister_adapter(intel_dp->aux.cec_adap);
 	kfree(intel_dp->aux.name);
 }
 
@@ -4587,6 +4589,7 @@ intel_dp_set_edid(struct intel_dp *intel_dp)
 	intel_connector->detect_edid = edid;
 
 	intel_dp->has_audio = drm_detect_monitor_audio(edid);
+	cec_s_phys_addr_from_edid(intel_dp->aux.cec_adap, edid);
 }
 
 static void
@@ -4596,6 +4599,7 @@ intel_dp_unset_edid(struct intel_dp *intel_dp)
 
 	kfree(intel_connector->detect_edid);
 	intel_connector->detect_edid = NULL;
+	cec_phys_addr_invalidate(intel_dp->aux.cec_adap);
 
 	intel_dp->has_audio = false;
 }
@@ -4616,13 +4620,17 @@ intel_dp_long_pulse(struct intel_connector *intel_connector)
 	intel_display_power_get(to_i915(dev), intel_dp->aux_power_domain);
 
 	/* Can't disconnect eDP, but you can close the lid... */
-	if (is_edp(intel_dp))
+	if (is_edp(intel_dp)) {
 		status = edp_detect(intel_dp);
-	else if (intel_digital_port_connected(to_i915(dev),
-					      dp_to_dig_port(intel_dp)))
+	} else if (intel_digital_port_connected(to_i915(dev),
+						dp_to_dig_port(intel_dp))) {
 		status = intel_dp_detect_dpcd(intel_dp);
-	else
+		if (status == connector_status_connected)
+			drm_dp_cec_configure_adapter(&intel_dp->aux,
+				     intel_dp->aux.name, dev->dev);
+	} else {
 		status = connector_status_disconnected;
+	}
 
 	if (status == connector_status_disconnected) {
 		memset(&intel_dp->compliance, 0, sizeof(intel_dp->compliance));
@@ -5011,6 +5019,8 @@ intel_dp_hpd_pulse(struct intel_digital_port *intel_dig_port, bool long_hpd)
 
 	intel_display_power_get(dev_priv, intel_dp->aux_power_domain);
 
+	drm_dp_cec_irq(&intel_dp->aux);
+
 	if (intel_dp->is_mst) {
 		if (intel_dp_check_mst_status(intel_dp) == -EINVAL) {
 			/*
-- 
2.13.2