drm/amd/display: query hdcp capability during link detect

[Why]
Query the hdcp caps of a link, it is useful and can be reported to the user

[How]
Create a query function and call it during link detect

Signed-off-by: Bhawanpreet Lakha <[e-mail]>
Reviewed-by: Rodrigo Siqueira <[e-mail]>
Signed-off-by: Alex Deucher <[e-mail]>

drivers/gpu/drm/amd/display/dc/core/dc_link.c

···
 	link->local_sink = prev_sink;
 }
 
+#if defined(CONFIG_DRM_AMD_DC_HDCP)
+static void query_hdcp_capability(enum signal_type signal, struct dc_link *link)
+{
+	struct hdcp_protection_message msg22;
+	struct hdcp_protection_message msg14;
+
+	memset(&msg22, 0, sizeof(struct hdcp_protection_message));
+	memset(&msg14, 0, sizeof(struct hdcp_protection_message));
+	memset(link->hdcp_caps.rx_caps.raw, 0,
+		sizeof(link->hdcp_caps.rx_caps.raw));
+
+	if ((link->connector_signal == SIGNAL_TYPE_DISPLAY_PORT &&
+			link->ddc->transaction_type ==
+			DDC_TRANSACTION_TYPE_I2C_OVER_AUX) ||
+			link->connector_signal == SIGNAL_TYPE_EDP) {
+		msg22.data = link->hdcp_caps.rx_caps.raw;
+		msg22.length = sizeof(link->hdcp_caps.rx_caps.raw);
+		msg22.msg_id = HDCP_MESSAGE_ID_RX_CAPS;
+	} else {
+		msg22.data = &link->hdcp_caps.rx_caps.fields.version;
+		msg22.length = sizeof(link->hdcp_caps.rx_caps.fields.version);
+		msg22.msg_id = HDCP_MESSAGE_ID_HDCP2VERSION;
+	}
+	msg22.version = HDCP_VERSION_22;
+	msg22.link = HDCP_LINK_PRIMARY;
+	msg22.max_retries = 5;
+	dc_process_hdcp_msg(signal, link, &msg22);
+
+	if (signal == SIGNAL_TYPE_DISPLAY_PORT || signal == SIGNAL_TYPE_DISPLAY_PORT_MST) {
+		enum hdcp_message_status status = HDCP_MESSAGE_UNSUPPORTED;
+
+		msg14.data = &link->hdcp_caps.bcaps.raw;
+		msg14.length = sizeof(link->hdcp_caps.bcaps.raw);
+		msg14.msg_id = HDCP_MESSAGE_ID_READ_BCAPS;
+		msg14.version = HDCP_VERSION_14;
+		msg14.link = HDCP_LINK_PRIMARY;
+		msg14.max_retries = 5;
+
+		status = dc_process_hdcp_msg(signal, link, &msg14);
+	}
+
+}
+#endif
+
 static void read_current_link_settings_on_detect(struct dc_link *link)
 {
 	union lane_count_set lane_count_set = { {0} };
···
 			dal_ddc_service_set_transaction_type(link->ddc,
 							     sink_caps->transaction_type);
 
+#if defined(CONFIG_DRM_AMD_DC_HDCP)
+			/* In case of fallback to SST when topology discovery below fails
+			 * HDCP caps will be querried again later by the upper layer (caller
+			 * of this function). */
+			query_hdcp_capability(SIGNAL_TYPE_DISPLAY_PORT_MST, link);
+#endif
 			/*
 			 * This call will initiate MST topology discovery. Which
 			 * will detect MST ports and add new DRM connector DRM
···
 			 * TODO debug why Dell 2413 doesn't like
 			 *  two link trainings
 			 */
+#if defined(CONFIG_DRM_AMD_DC_HDCP)
+			query_hdcp_capability(sink->sink_signal, link);
+#endif
 
 			// verify link cap for SST non-seamless boot
 			if (!perform_dp_seamless_boot)
···
 				sink = prev_sink;
 				prev_sink = NULL;
 			}
+#if defined(CONFIG_DRM_AMD_DC_HDCP)
+			query_hdcp_capability(sink->sink_signal, link);
+#endif
 		}
 
 		/* HDMI-DVI Dongle */

drivers/gpu/drm/amd/display/dc/dc.h

···
 #include "dc_types.h"
 #include "grph_object_defs.h"
 #include "logger_types.h"
+#if defined(CONFIG_DRM_AMD_DC_HDCP)
+#include "hdcp_types.h"
+#endif
 #include "gpio_types.h"
 #include "link_service_types.h"
 #include "grph_object_ctrl_defs.h"
···
 	uint8_t raw;
 };
 
+#if defined(CONFIG_DRM_AMD_DC_HDCP)
+union hdcp_rx_caps {
+	struct {
+		uint8_t version;
+		uint8_t reserved;
+		struct {
+			uint8_t repeater	: 1;
+			uint8_t hdcp_capable	: 1;
+			uint8_t reserved	: 6;
+		} byte0;
+	} fields;
+	uint8_t raw[3];
+};
+
+union hdcp_bcaps {
+	struct {
+		uint8_t HDCP_CAPABLE:1;
+		uint8_t REPEATER:1;
+		uint8_t RESERVED:6;
+	} bits;
+	uint8_t raw;
+};
+
+struct hdcp_caps {
+	union hdcp_rx_caps rx_caps;
+	union hdcp_bcaps bcaps;
+};
+#endif
+
 #include "dc_link.h"
 
 /*******************************************************************************
···
 unsigned int dc_get_current_backlight_pwm(struct dc *dc);
 unsigned int dc_get_target_backlight_pwm(struct dc *dc);
 
+#if defined(CONFIG_DRM_AMD_DC_HDCP)
+/*
+ * HDCP Interfaces
+ */
+enum hdcp_message_status dc_process_hdcp_msg(
+		enum signal_type signal,
+		struct dc_link *link,
+		struct hdcp_protection_message *message_info);
+#endif
 bool dc_is_dmcu_initialized(struct dc *dc);
 
 enum dc_status dc_set_clock(struct dc *dc, enum dc_clock_type clock_type, uint32_t clk_khz, uint32_t stepping);

drivers/gpu/drm/amd/display/dc/dc_link.h

···
 	uint32_t dongle_max_pix_clk;
 	unsigned short chip_caps;
 	unsigned int dpcd_sink_count;
+#if defined(CONFIG_DRM_AMD_DC_HDCP)
+	struct hdcp_caps hdcp_caps;
+#endif
 	enum edp_revision edp_revision;
 	bool psr_feature_enabled;
 	bool psr_allow_active;

drivers/gpu/drm/amd/display/dc/hdcp/hdcp_msg.c

···
 	.process_transaction = dp_11_process_transaction
 };
 
+static const struct protection_properties *get_protection_properties_by_signal(
+	struct dc_link *link,
+	enum signal_type st,
+	enum hdcp_version version)
+{
+	switch (version) {
+	case HDCP_VERSION_14:
+		switch (st) {
+		case SIGNAL_TYPE_DVI_SINGLE_LINK:
+		case SIGNAL_TYPE_DVI_DUAL_LINK:
+		case SIGNAL_TYPE_HDMI_TYPE_A:
+			return &hdmi_14_protection;
+		case SIGNAL_TYPE_DISPLAY_PORT:
+			if (link &&
+				(link->dpcd_caps.dongle_type == DISPLAY_DONGLE_DP_VGA_CONVERTER ||
+				link->dpcd_caps.dongle_caps.dongle_type == DISPLAY_DONGLE_DP_VGA_CONVERTER)) {
+				return &non_supported_protection;
+			}
+			return &dp_11_protection;
+		case SIGNAL_TYPE_DISPLAY_PORT_MST:
+		case SIGNAL_TYPE_EDP:
+			return &dp_11_protection;
+		default:
+			return &non_supported_protection;
+		}
+		break;
+	case HDCP_VERSION_22:
+		switch (st) {
+		case SIGNAL_TYPE_DVI_SINGLE_LINK:
+		case SIGNAL_TYPE_DVI_DUAL_LINK:
+		case SIGNAL_TYPE_HDMI_TYPE_A:
+			return &hdmi_14_protection; //todo version2.2
+		case SIGNAL_TYPE_DISPLAY_PORT:
+		case SIGNAL_TYPE_DISPLAY_PORT_MST:
+		case SIGNAL_TYPE_EDP:
+			return &dp_11_protection;  //todo version2.2
+		default:
+			return &non_supported_protection;
+		}
+		break;
+	default:
+		return &non_supported_protection;
+	}
+}
+
+enum hdcp_message_status dc_process_hdcp_msg(
+	enum signal_type signal,
+	struct dc_link *link,
+	struct hdcp_protection_message *message_info)
+{
+	enum hdcp_message_status status = HDCP_MESSAGE_FAILURE;
+	uint32_t i = 0;
+
+	const struct protection_properties *protection_props;
+
+	if (!message_info)
+		return HDCP_MESSAGE_UNSUPPORTED;
+
+	if (message_info->msg_id < HDCP_MESSAGE_ID_READ_BKSV ||
+		message_info->msg_id >= HDCP_MESSAGE_ID_MAX)
+		return HDCP_MESSAGE_UNSUPPORTED;
+
+	protection_props =
+		get_protection_properties_by_signal(
+			link,
+			signal,
+			message_info->version);
+
+	if (!protection_props->supported)
+		return HDCP_MESSAGE_UNSUPPORTED;
+
+	if (protection_props->process_transaction(
+		link,
+		message_info)) {
+		status = HDCP_MESSAGE_SUCCESS;
+	} else {
+		for (i = 0; i < message_info->max_retries; i++) {
+			if (protection_props->process_transaction(
+						link,
+						message_info)) {
+				status = HDCP_MESSAGE_SUCCESS;
+				break;
+			}
+		}
+	}
+
+	return status;
+}
+

drivers/gpu/drm/amd/display/include/hdcp_types.h

···
 	HDCP_LINK_SECONDARY
 };
 
+enum hdcp_message_status {
+	HDCP_MESSAGE_SUCCESS,
+	HDCP_MESSAGE_FAILURE,
+	HDCP_MESSAGE_UNSUPPORTED
+};
+
 struct hdcp_protection_message {
 	enum hdcp_version version;
 	/* relevant only for DVI */
···
 	uint32_t length;
 	uint8_t max_retries;
 	uint8_t *data;
+	enum hdcp_message_status status;
 };
 
 #endif