drm/i915: Implement the HDCP2.2 support for DP

Implements the DP adaptation specific HDCP2.2 functions.

These functions perform the DPCD read and write for communicating the
HDCP2.2 auth message back and forth.

v2:
  wait for cp_irq is merged with this patch. Rebased.
v3:
  wait_queue is used for wait for cp_irq [Chris Wilson]
v4:
  Style fixed.
  %s/PARING/PAIRING
  Few style fixes [Uma]
v5:
  Lookup table for DP HDCP2.2 msg details [Daniel].
  Extra lines are removed.
v6: Rebased.
v7:
  Fixed some regression introduced at v5. [Ankit]
  Macro HDCP_2_2_RX_CAPS_VERSION_VAL is reused [Uma]
  Converted a function to inline [Uma]
  %s/uintxx_t/uxx
v8:
  Error due to the sinks are reported as DEBUG logs.
  Adjust to the new mei interface.
v9:
  ARRAY_SIZE for no of array members [Jon & Daniel]
  return of the wait_for_cp_irq is made as void [Daniel]
  Wait for HDCP2.2 msg is done based on polling the reg bit than
    CP_IRQ based. [Daniel]
  hdcp adaptation is added as a const in the hdcp_shim [Daniel]
v10:
  config_stream_type is redefined [Daniel]
  DP Errata specific defines are moved into intel_dp.c.
Signed-off-by: Ramalingam C <ramalingam.c@intel.com>
Signed-off-by: Ankit K Nautiyal <ankit.k.nautiyal@intel.com>
Reviewed-by: Uma Shankar <uma.shankar@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/1550338640-17470-14-git-send-email-ramalingam.c@intel.com

drivers/gpu/drm/i915/intel_dp.c

@@ -5847,6 +5847,333 @@ int intel_dp_hdcp_capable(struct intel_digital_port *intel_dig_port,
 	return 0;
 }
 
+struct hdcp2_dp_errata_stream_type {
+	u8	msg_id;
+	u8	stream_type;
+} __packed;
+
+static struct hdcp2_dp_msg_data {
+	u8 msg_id;
+	u32 offset;
+	bool msg_detectable;
+	u32 timeout;
+	u32 timeout2; /* Added for non_paired situation */
+	} hdcp2_msg_data[] = {
+		{HDCP_2_2_AKE_INIT, DP_HDCP_2_2_AKE_INIT_OFFSET, false, 0, 0},
+		{HDCP_2_2_AKE_SEND_CERT, DP_HDCP_2_2_AKE_SEND_CERT_OFFSET,
+				false, HDCP_2_2_CERT_TIMEOUT_MS, 0},
+		{HDCP_2_2_AKE_NO_STORED_KM, DP_HDCP_2_2_AKE_NO_STORED_KM_OFFSET,
+				false, 0, 0},
+		{HDCP_2_2_AKE_STORED_KM, DP_HDCP_2_2_AKE_STORED_KM_OFFSET,
+				false, 0, 0},
+		{HDCP_2_2_AKE_SEND_HPRIME, DP_HDCP_2_2_AKE_SEND_HPRIME_OFFSET,
+				true, HDCP_2_2_HPRIME_PAIRED_TIMEOUT_MS,
+				HDCP_2_2_HPRIME_NO_PAIRED_TIMEOUT_MS},
+		{HDCP_2_2_AKE_SEND_PAIRING_INFO,
+				DP_HDCP_2_2_AKE_SEND_PAIRING_INFO_OFFSET, true,
+				HDCP_2_2_PAIRING_TIMEOUT_MS, 0},
+		{HDCP_2_2_LC_INIT, DP_HDCP_2_2_LC_INIT_OFFSET, false, 0, 0},
+		{HDCP_2_2_LC_SEND_LPRIME, DP_HDCP_2_2_LC_SEND_LPRIME_OFFSET,
+				false, HDCP_2_2_DP_LPRIME_TIMEOUT_MS, 0},
+		{HDCP_2_2_SKE_SEND_EKS, DP_HDCP_2_2_SKE_SEND_EKS_OFFSET, false,
+				0, 0},
+		{HDCP_2_2_REP_SEND_RECVID_LIST,
+				DP_HDCP_2_2_REP_SEND_RECVID_LIST_OFFSET, true,
+				HDCP_2_2_RECVID_LIST_TIMEOUT_MS, 0},
+		{HDCP_2_2_REP_SEND_ACK, DP_HDCP_2_2_REP_SEND_ACK_OFFSET, false,
+				0, 0},
+		{HDCP_2_2_REP_STREAM_MANAGE,
+				DP_HDCP_2_2_REP_STREAM_MANAGE_OFFSET, false,
+				0, 0},
+		{HDCP_2_2_REP_STREAM_READY, DP_HDCP_2_2_REP_STREAM_READY_OFFSET,
+				false, HDCP_2_2_STREAM_READY_TIMEOUT_MS, 0},
+/* local define to shovel this through the write_2_2 interface */
+#define HDCP_2_2_ERRATA_DP_STREAM_TYPE	50
+		{HDCP_2_2_ERRATA_DP_STREAM_TYPE,
+				DP_HDCP_2_2_REG_STREAM_TYPE_OFFSET, false,
+				0, 0},
+		};
+
+static inline
+int intel_dp_hdcp2_read_rx_status(struct intel_digital_port *intel_dig_port,
+				  u8 *rx_status)
+{
+	ssize_t ret;
+
+	ret = drm_dp_dpcd_read(&intel_dig_port->dp.aux,
+			       DP_HDCP_2_2_REG_RXSTATUS_OFFSET, rx_status,
+			       HDCP_2_2_DP_RXSTATUS_LEN);
+	if (ret != HDCP_2_2_DP_RXSTATUS_LEN) {
+		DRM_DEBUG_KMS("Read bstatus from DP/AUX failed (%zd)\n", ret);
+		return ret >= 0 ? -EIO : ret;
+	}
+
+	return 0;
+}
+
+static
+int hdcp2_detect_msg_availability(struct intel_digital_port *intel_dig_port,
+				  u8 msg_id, bool *msg_ready)
+{
+	u8 rx_status;
+	int ret;
+
+	*msg_ready = false;
+	ret = intel_dp_hdcp2_read_rx_status(intel_dig_port, &rx_status);
+	if (ret < 0)
+		return ret;
+
+	switch (msg_id) {
+	case HDCP_2_2_AKE_SEND_HPRIME:
+		if (HDCP_2_2_DP_RXSTATUS_H_PRIME(rx_status))
+			*msg_ready = true;
+		break;
+	case HDCP_2_2_AKE_SEND_PAIRING_INFO:
+		if (HDCP_2_2_DP_RXSTATUS_PAIRING(rx_status))
+			*msg_ready = true;
+		break;
+	case HDCP_2_2_REP_SEND_RECVID_LIST:
+		if (HDCP_2_2_DP_RXSTATUS_READY(rx_status))
+			*msg_ready = true;
+		break;
+	default:
+		DRM_ERROR("Unidentified msg_id: %d\n", msg_id);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static ssize_t
+intel_dp_hdcp2_wait_for_msg(struct intel_digital_port *intel_dig_port,
+			    struct hdcp2_dp_msg_data *hdcp2_msg_data)
+{
+	struct intel_dp *dp = &intel_dig_port->dp;
+	struct intel_hdcp *hdcp = &dp->attached_connector->hdcp;
+	u8 msg_id = hdcp2_msg_data->msg_id;
+	int ret, timeout;
+	bool msg_ready = false;
+
+	if (msg_id == HDCP_2_2_AKE_SEND_HPRIME && !hdcp->is_paired)
+		timeout = hdcp2_msg_data->timeout2;
+	else
+		timeout = hdcp2_msg_data->timeout;
+
+	/*
+	 * There is no way to detect the CERT, LPRIME and STREAM_READY
+	 * availability. So Wait for timeout and read the msg.
+	 */
+	if (!hdcp2_msg_data->msg_detectable) {
+		mdelay(timeout);
+		ret = 0;
+	} else {
+		/* TODO: In case if you need to wait on CP_IRQ, do it here */
+		ret = __wait_for(ret =
+				 hdcp2_detect_msg_availability(intel_dig_port,
+							       msg_id,
+							       &msg_ready),
+				 !ret && msg_ready, timeout * 1000,
+				 1000, 5 * 1000);
+
+		if (!msg_ready)
+			ret = -ETIMEDOUT;
+	}
+
+	if (ret)
+		DRM_DEBUG_KMS("msg_id %d, ret %d, timeout(mSec): %d\n",
+			      hdcp2_msg_data->msg_id, ret, timeout);
+
+	return ret;
+}
+
+static struct hdcp2_dp_msg_data *get_hdcp2_dp_msg_data(u8 msg_id)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(hdcp2_msg_data); i++)
+		if (hdcp2_msg_data[i].msg_id == msg_id)
+			return &hdcp2_msg_data[i];
+
+	return NULL;
+}
+
+static
+int intel_dp_hdcp2_write_msg(struct intel_digital_port *intel_dig_port,
+			     void *buf, size_t size)
+{
+	unsigned int offset;
+	u8 *byte = buf;
+	ssize_t ret, bytes_to_write, len;
+	struct hdcp2_dp_msg_data *hdcp2_msg_data;
+
+	hdcp2_msg_data = get_hdcp2_dp_msg_data(*byte);
+	if (!hdcp2_msg_data)
+		return -EINVAL;
+
+	offset = hdcp2_msg_data->offset;
+
+	/* No msg_id in DP HDCP2.2 msgs */
+	bytes_to_write = size - 1;
+	byte++;
+
+	while (bytes_to_write) {
+		len = bytes_to_write > DP_AUX_MAX_PAYLOAD_BYTES ?
+				DP_AUX_MAX_PAYLOAD_BYTES : bytes_to_write;
+
+		ret = drm_dp_dpcd_write(&intel_dig_port->dp.aux,
+					offset, (void *)byte, len);
+		if (ret < 0)
+			return ret;
+
+		bytes_to_write -= ret;
+		byte += ret;
+		offset += ret;
+	}
+
+	return size;
+}
+
+static
+ssize_t get_receiver_id_list_size(struct intel_digital_port *intel_dig_port)
+{
+	u8 rx_info[HDCP_2_2_RXINFO_LEN];
+	u32 dev_cnt;
+	ssize_t ret;
+
+	ret = drm_dp_dpcd_read(&intel_dig_port->dp.aux,
+			       DP_HDCP_2_2_REG_RXINFO_OFFSET,
+			       (void *)rx_info, HDCP_2_2_RXINFO_LEN);
+	if (ret != HDCP_2_2_RXINFO_LEN)
+		return ret >= 0 ? -EIO : ret;
+
+	dev_cnt = (HDCP_2_2_DEV_COUNT_HI(rx_info[0]) << 4 |
+		   HDCP_2_2_DEV_COUNT_LO(rx_info[1]));
+
+	if (dev_cnt > HDCP_2_2_MAX_DEVICE_COUNT)
+		dev_cnt = HDCP_2_2_MAX_DEVICE_COUNT;
+
+	ret = sizeof(struct hdcp2_rep_send_receiverid_list) -
+		HDCP_2_2_RECEIVER_IDS_MAX_LEN +
+		(dev_cnt * HDCP_2_2_RECEIVER_ID_LEN);
+
+	return ret;
+}
+
+static
+int intel_dp_hdcp2_read_msg(struct intel_digital_port *intel_dig_port,
+			    u8 msg_id, void *buf, size_t size)
+{
+	unsigned int offset;
+	u8 *byte = buf;
+	ssize_t ret, bytes_to_recv, len;
+	struct hdcp2_dp_msg_data *hdcp2_msg_data;
+
+	hdcp2_msg_data = get_hdcp2_dp_msg_data(msg_id);
+	if (!hdcp2_msg_data)
+		return -EINVAL;
+	offset = hdcp2_msg_data->offset;
+
+	ret = intel_dp_hdcp2_wait_for_msg(intel_dig_port, hdcp2_msg_data);
+	if (ret < 0)
+		return ret;
+
+	if (msg_id == HDCP_2_2_REP_SEND_RECVID_LIST) {
+		ret = get_receiver_id_list_size(intel_dig_port);
+		if (ret < 0)
+			return ret;
+
+		size = ret;
+	}
+	bytes_to_recv = size - 1;
+
+	/* DP adaptation msgs has no msg_id */
+	byte++;
+
+	while (bytes_to_recv) {
+		len = bytes_to_recv > DP_AUX_MAX_PAYLOAD_BYTES ?
+		      DP_AUX_MAX_PAYLOAD_BYTES : bytes_to_recv;
+
+		ret = drm_dp_dpcd_read(&intel_dig_port->dp.aux, offset,
+				       (void *)byte, len);
+		if (ret < 0) {
+			DRM_DEBUG_KMS("msg_id %d, ret %zd\n", msg_id, ret);
+			return ret;
+		}
+
+		bytes_to_recv -= ret;
+		byte += ret;
+		offset += ret;
+	}
+	byte = buf;
+	*byte = msg_id;
+
+	return size;
+}
+
+static
+int intel_dp_hdcp2_config_stream_type(struct intel_digital_port *intel_dig_port,
+				      bool is_repeater, u8 content_type)
+{
+	struct hdcp2_dp_errata_stream_type stream_type_msg;
+
+	if (is_repeater)
+		return 0;
+
+	/*
+	 * Errata for DP: As Stream type is used for encryption, Receiver
+	 * should be communicated with stream type for the decryption of the
+	 * content.
+	 * Repeater will be communicated with stream type as a part of it's
+	 * auth later in time.
+	 */
+	stream_type_msg.msg_id = HDCP_2_2_ERRATA_DP_STREAM_TYPE;
+	stream_type_msg.stream_type = content_type;
+
+	return intel_dp_hdcp2_write_msg(intel_dig_port, &stream_type_msg,
+					sizeof(stream_type_msg));
+}
+
+static
+int intel_dp_hdcp2_check_link(struct intel_digital_port *intel_dig_port)
+{
+	u8 rx_status;
+	int ret;
+
+	ret = intel_dp_hdcp2_read_rx_status(intel_dig_port, &rx_status);
+	if (ret)
+		return ret;
+
+	if (HDCP_2_2_DP_RXSTATUS_REAUTH_REQ(rx_status))
+		ret = HDCP_REAUTH_REQUEST;
+	else if (HDCP_2_2_DP_RXSTATUS_LINK_FAILED(rx_status))
+		ret = HDCP_LINK_INTEGRITY_FAILURE;
+	else if (HDCP_2_2_DP_RXSTATUS_READY(rx_status))
+		ret = HDCP_TOPOLOGY_CHANGE;
+
+	return ret;
+}
+
+static
+int intel_dp_hdcp2_capable(struct intel_digital_port *intel_dig_port,
+			   bool *capable)
+{
+	u8 rx_caps[3];
+	int ret;
+
+	*capable = false;
+	ret = drm_dp_dpcd_read(&intel_dig_port->dp.aux,
+			       DP_HDCP_2_2_REG_RX_CAPS_OFFSET,
+			       rx_caps, HDCP_2_2_RXCAPS_LEN);
+	if (ret != HDCP_2_2_RXCAPS_LEN)
+		return ret >= 0 ? -EIO : ret;
+
+	if (rx_caps[0] == HDCP_2_2_RX_CAPS_VERSION_VAL &&
+	    HDCP_2_2_DP_HDCP_CAPABLE(rx_caps[2]))
+		*capable = true;
+
+	return 0;
+}
+
 static const struct intel_hdcp_shim intel_dp_hdcp_shim = {
 	.write_an_aksv = intel_dp_hdcp_write_an_aksv,
 	.read_bksv = intel_dp_hdcp_read_bksv,
@@ -5859,6 +6186,12 @@ static const struct intel_hdcp_shim intel_dp_hdcp_shim = {
 	.toggle_signalling = intel_dp_hdcp_toggle_signalling,
 	.check_link = intel_dp_hdcp_check_link,
 	.hdcp_capable = intel_dp_hdcp_capable,
+	.write_2_2_msg = intel_dp_hdcp2_write_msg,
+	.read_2_2_msg = intel_dp_hdcp2_read_msg,
+	.config_stream_type = intel_dp_hdcp2_config_stream_type,
+	.check_2_2_link = intel_dp_hdcp2_check_link,
+	.hdcp_2_2_capable = intel_dp_hdcp2_capable,
+	.protocol = HDCP_PROTOCOL_DP,
 };
 
 static void intel_edp_panel_vdd_sanitize(struct intel_dp *intel_dp)