drm/i915: Add HDCP 1.4 support for MST connectors

Now that all the groundwork has been laid, we can turn on HDCP 1.4 over
MST. Everything except for toggling the HDCP signalling and HDCP 2.2
support is the same as the DP case, so we'll re-use those callbacks

Cc: Juston Li <juston.li@intel.com>
Reviewed-by: Anshuman Gupta <anshuman.gupta@intel.com>
Signed-off-by: Sean Paul <seanpaul@chromium.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20191203173638.94919-12-sean@poorly.run #v1
Link: https://patchwork.freedesktop.org/patch/msgid/20191212190230.188505-13-sean@poorly.run #v2
Link: https://patchwork.freedesktop.org/patch/msgid/20200117193103.156821-13-sean@poorly.run #v3
Link: https://patchwork.freedesktop.org/patch/msgid/20200218220242.107265-15-sean@poorly.run #v4
Link: https://patchwork.freedesktop.org/patch/msgid/20200305201236.152307-17-sean@poorly.run #v5
Link: https://patchwork.freedesktop.org/patch/msgid/20200429195502.39919-17-sean@poorly.run #v6
Link: https://patchwork.freedesktop.org/patch/msgid/20200623155907.22961-18-sean@poorly.run #v7

Changes in v2:
-Toggle HDCP from encoder disable/enable
-Don't disable HDCP on MST connector destroy, leave that for encoder
 disable, just ensure the check_work routine isn't running any longer
Changes in v3:
-Place the shim in the new intel_dp_hdcp.c file (Ville)
Changes in v4:
-Actually use the mst shim for mst connections (Juston)
-Use QUERY_STREAM_ENC_STATUS MST message to verify channel is encrypted
Changes in v5:
-Add sleep on disable signalling to match hdmi delay
Changes in v6:
-Disable HDCP over MST on GEN12+ since I'm unsure how it should work and I
 don't have hardware to test it
Changes in v7:
-Remove hdcp2 shims for MST in favor of skipping hdcp2 init (Ramalingam)
Changes in v8:
-None

Signed-off-by: Ramalingam C <ramalingam.c@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200818153910.27894-18-sean@poorly.run

drivers/gpu/drm/i915/display/intel_dp_hdcp.c

@@ -7,10 +7,12 @@
  */
 
 #include <drm/drm_dp_helper.h>
+#include <drm/drm_dp_mst_helper.h>
 #include <drm/drm_hdcp.h>
 #include <drm/drm_print.h>
 
 #include "intel_display_types.h"
+#include "intel_ddi.h"
 #include "intel_dp.h"
 #include "intel_hdcp.h"
 
@@ -619,6 +621,65 @@ static const struct intel_hdcp_shim intel_dp_hdcp_shim = {
 	.protocol = HDCP_PROTOCOL_DP,
 };
 
+static int
+intel_dp_mst_hdcp_toggle_signalling(struct intel_digital_port *dig_port,
+				    enum transcoder cpu_transcoder,
+				    bool enable)
+{
+	struct drm_i915_private *i915 = to_i915(dig_port->base.base.dev);
+	int ret;
+
+	if (!enable)
+		usleep_range(6, 60); /* Bspec says >= 6us */
+
+	ret = intel_ddi_toggle_hdcp_signalling(&dig_port->base,
+					       cpu_transcoder, enable);
+	if (ret)
+		drm_dbg_kms(&i915->drm, "%s HDCP signalling failed (%d)\n",
+			      enable ? "Enable" : "Disable", ret);
+	return ret;
+}
+
+static
+bool intel_dp_mst_hdcp_check_link(struct intel_digital_port *dig_port,
+				  struct intel_connector *connector)
+{
+	struct drm_i915_private *i915 = to_i915(dig_port->base.base.dev);
+	struct intel_dp *intel_dp = &dig_port->dp;
+	struct drm_dp_query_stream_enc_status_ack_reply reply;
+	int ret;
+
+	if (!intel_dp_hdcp_check_link(dig_port, connector))
+		return false;
+
+	ret = drm_dp_send_query_stream_enc_status(&intel_dp->mst_mgr,
+						  connector->port, &reply);
+	if (ret) {
+		drm_dbg_kms(&i915->drm,
+			    "[CONNECTOR:%d:%s] failed QSES ret=%d\n",
+			    connector->base.base.id, connector->base.name, ret);
+		return false;
+	}
+
+	return reply.auth_completed && reply.encryption_enabled;
+}
+
+static const struct intel_hdcp_shim intel_dp_mst_hdcp_shim = {
+	.write_an_aksv = intel_dp_hdcp_write_an_aksv,
+	.read_bksv = intel_dp_hdcp_read_bksv,
+	.read_bstatus = intel_dp_hdcp_read_bstatus,
+	.repeater_present = intel_dp_hdcp_repeater_present,
+	.read_ri_prime = intel_dp_hdcp_read_ri_prime,
+	.read_ksv_ready = intel_dp_hdcp_read_ksv_ready,
+	.read_ksv_fifo = intel_dp_hdcp_read_ksv_fifo,
+	.read_v_prime_part = intel_dp_hdcp_read_v_prime_part,
+	.toggle_signalling = intel_dp_mst_hdcp_toggle_signalling,
+	.check_link = intel_dp_mst_hdcp_check_link,
+	.hdcp_capable = intel_dp_hdcp_capable,
+
+	.protocol = HDCP_PROTOCOL_DP,
+};
+
 int intel_dp_init_hdcp(struct intel_digital_port *dig_port,
 		       struct intel_connector *intel_connector)
 {
@@ -631,7 +692,10 @@ int intel_dp_init_hdcp(struct intel_digital_port *dig_port,
 	if (!is_hdcp_supported(dev_priv, port))
 		return 0;
 
-	if (!intel_dp_is_edp(intel_dp))
+	if (intel_connector->mst_port)
+		return intel_hdcp_init(intel_connector, port,
+				       &intel_dp_mst_hdcp_shim);
+	else if (!intel_dp_is_edp(intel_dp))
 		return intel_hdcp_init(intel_connector, port,
 				       &intel_dp_hdcp_shim);
 

drivers/gpu/drm/i915/display/intel_dp_mst.c

@@ -37,6 +37,7 @@
 #include "intel_dp.h"
 #include "intel_dp_mst.h"
 #include "intel_dpio_phy.h"
+#include "intel_hdcp.h"
 
 static int intel_dp_mst_compute_link_config(struct intel_encoder *encoder,
 					    struct intel_crtc_state *crtc_state,
@@ -352,6 +353,8 @@ static void intel_mst_disable_dp(struct intel_atomic_state *state,
 	drm_dbg_kms(&i915->drm, "active links %d\n",
 		    intel_dp->active_mst_links);
 
+	intel_hdcp_disable(intel_mst->connector);
+
 	drm_dp_mst_reset_vcpi_slots(&intel_dp->mst_mgr, connector->port);
 
 	ret = drm_dp_update_payload_part1(&intel_dp->mst_mgr);
@@ -556,6 +559,13 @@ static void intel_mst_enable_dp(struct intel_atomic_state *state,
 
 	if (pipe_config->has_audio)
 		intel_audio_codec_enable(encoder, pipe_config, conn_state);
+
+	/* Enable hdcp if it's desired */
+	if (conn_state->content_protection ==
+	    DRM_MODE_CONTENT_PROTECTION_DESIRED)
+		intel_hdcp_enable(to_intel_connector(conn_state->connector),
+				  pipe_config->cpu_transcoder,
+				  (u8)conn_state->hdcp_content_type);
 }
 
 static bool intel_dp_mst_enc_get_hw_state(struct intel_encoder *encoder,
@@ -799,6 +809,14 @@ static struct drm_connector *intel_dp_add_mst_connector(struct drm_dp_mst_topolo
 	intel_attach_force_audio_property(connector);
 	intel_attach_broadcast_rgb_property(connector);
 
+
+	/* TODO: Figure out how to make HDCP work on GEN12+ */
+	if (INTEL_GEN(dev_priv) < 12) {
+		ret = intel_dp_init_hdcp(dig_port, intel_connector);
+		if (ret)
+			DRM_DEBUG_KMS("HDCP init failed, skipping.\n");
+	}
+
 	/*
 	 * Reuse the prop from the SST connector because we're
 	 * not allowed to create new props after device registration.

drivers/gpu/drm/i915/display/intel_hdcp.c

@@ -2050,7 +2050,7 @@ int intel_hdcp_init(struct intel_connector *connector,
 	if (!shim)
 		return -EINVAL;
 
-	if (is_hdcp2_supported(dev_priv))
+	if (is_hdcp2_supported(dev_priv) && !connector->mst_port)
 		intel_hdcp2_init(connector, port, shim);
 
 	ret =