1 files changed, 358 insertions, 96 deletions

diff --git a/drivers/video/hdmi.c b/drivers/video/hdmi.c
index 799ae49774f5..45b42f14a750 100644
--- a/drivers/video/hdmi.c
+++ b/drivers/video/hdmi.c
@@ -21,6 +21,7 @@
  * DEALINGS IN THE SOFTWARE.
  */
 
+#include <drm/display/drm_dp.h>
 #include <linux/bitops.h>
 #include <linux/bug.h>
 #include <linux/errno.h>
@@ -53,18 +54,14 @@ static void hdmi_infoframe_set_checksum(void *buffer, size_t size)
 /**
  * hdmi_avi_infoframe_init() - initialize an HDMI AVI infoframe
  * @frame: HDMI AVI infoframe
- *
- * Returns 0 on success or a negative error code on failure.
  */
-int hdmi_avi_infoframe_init(struct hdmi_avi_infoframe *frame)
+void hdmi_avi_infoframe_init(struct hdmi_avi_infoframe *frame)
 {
 	memset(frame, 0, sizeof(*frame));
 
 	frame->type = HDMI_INFOFRAME_TYPE_AVI;
 	frame->version = 2;
 	frame->length = HDMI_AVI_INFOFRAME_SIZE;
-
-	return 0;
 }
 EXPORT_SYMBOL(hdmi_avi_infoframe_init);
 
@@ -225,14 +222,18 @@ EXPORT_SYMBOL(hdmi_avi_infoframe_pack);
 int hdmi_spd_infoframe_init(struct hdmi_spd_infoframe *frame,
 			    const char *vendor, const char *product)
 {
+	size_t len;
+
 	memset(frame, 0, sizeof(*frame));
 
 	frame->type = HDMI_INFOFRAME_TYPE_SPD;
 	frame->version = 1;
 	frame->length = HDMI_SPD_INFOFRAME_SIZE;
 
-	strncpy(frame->vendor, vendor, sizeof(frame->vendor));
-	strncpy(frame->product, product, sizeof(frame->product));
+	len = strlen(vendor);
+	memcpy(frame->vendor, vendor, min(len, sizeof(frame->vendor)));
+	len = strlen(product);
+	memcpy(frame->product, product, min(len, sizeof(frame->product)));
 
 	return 0;
 }
@@ -381,12 +382,34 @@ static int hdmi_audio_infoframe_check_only(const struct hdmi_audio_infoframe *fr
  *
  * Returns 0 on success or a negative error code on failure.
  */
-int hdmi_audio_infoframe_check(struct hdmi_audio_infoframe *frame)
+int hdmi_audio_infoframe_check(const struct hdmi_audio_infoframe *frame)
 {
 	return hdmi_audio_infoframe_check_only(frame);
 }
 EXPORT_SYMBOL(hdmi_audio_infoframe_check);
 
+static void
+hdmi_audio_infoframe_pack_payload(const struct hdmi_audio_infoframe *frame,
+				  u8 *buffer)
+{
+	u8 channels;
+
+	if (frame->channels >= 2)
+		channels = frame->channels - 1;
+	else
+		channels = 0;
+
+	buffer[0] = ((frame->coding_type & 0xf) << 4) | (channels & 0x7);
+	buffer[1] = ((frame->sample_frequency & 0x7) << 2) |
+		 (frame->sample_size & 0x3);
+	buffer[2] = frame->coding_type_ext & 0x1f;
+	buffer[3] = frame->channel_allocation;
+	buffer[4] = (frame->level_shift_value & 0xf) << 3;
+
+	if (frame->downmix_inhibit)
+		buffer[4] |= BIT(7);
+}
+
 /**
  * hdmi_audio_infoframe_pack_only() - write HDMI audio infoframe to binary buffer
  * @frame: HDMI audio infoframe
@@ -404,7 +427,6 @@ EXPORT_SYMBOL(hdmi_audio_infoframe_check);
 ssize_t hdmi_audio_infoframe_pack_only(const struct hdmi_audio_infoframe *frame,
 				       void *buffer, size_t size)
 {
-	unsigned char channels;
 	u8 *ptr = buffer;
 	size_t length;
 	int ret;
@@ -420,28 +442,13 @@ ssize_t hdmi_audio_infoframe_pack_only(const struct hdmi_audio_infoframe *frame,
 
 	memset(buffer, 0, size);
 
-	if (frame->channels >= 2)
-		channels = frame->channels - 1;
-	else
-		channels = 0;
-
 	ptr[0] = frame->type;
 	ptr[1] = frame->version;
 	ptr[2] = frame->length;
 	ptr[3] = 0; /* checksum */
 
-	/* start infoframe payload */
-	ptr += HDMI_INFOFRAME_HEADER_SIZE;
-
-	ptr[0] = ((frame->coding_type & 0xf) << 4) | (channels & 0x7);
-	ptr[1] = ((frame->sample_frequency & 0x7) << 2) |
-		 (frame->sample_size & 0x3);
-	ptr[2] = frame->coding_type_ext & 0x1f;
-	ptr[3] = frame->channel_allocation;
-	ptr[4] = (frame->level_shift_value & 0xf) << 3;
-
-	if (frame->downmix_inhibit)
-		ptr[4] |= BIT(7);
+	hdmi_audio_infoframe_pack_payload(frame,
+					  ptr + HDMI_INFOFRAME_HEADER_SIZE);
 
 	hdmi_infoframe_set_checksum(buffer, length);
 
@@ -480,6 +487,43 @@ ssize_t hdmi_audio_infoframe_pack(struct hdmi_audio_infoframe *frame,
 EXPORT_SYMBOL(hdmi_audio_infoframe_pack);
 
 /**
+ * hdmi_audio_infoframe_pack_for_dp - Pack a HDMI Audio infoframe for DisplayPort
+ *
+ * @frame:      HDMI Audio infoframe
+ * @sdp:        Secondary data packet for DisplayPort.
+ * @dp_version: DisplayPort version to be encoded in the header
+ *
+ * Packs a HDMI Audio Infoframe to be sent over DisplayPort. This function
+ * fills the secondary data packet to be used for DisplayPort.
+ *
+ * Return: Number of total written bytes or a negative errno on failure.
+ */
+ssize_t
+hdmi_audio_infoframe_pack_for_dp(const struct hdmi_audio_infoframe *frame,
+				 struct dp_sdp *sdp, u8 dp_version)
+{
+	int ret;
+
+	ret = hdmi_audio_infoframe_check(frame);
+	if (ret)
+		return ret;
+
+	memset(sdp->db, 0, sizeof(sdp->db));
+
+	/* Secondary-data packet header */
+	sdp->sdp_header.HB0 = 0;
+	sdp->sdp_header.HB1 = frame->type;
+	sdp->sdp_header.HB2 = DP_SDP_AUDIO_INFOFRAME_HB2;
+	sdp->sdp_header.HB3 = (dp_version & 0x3f) << 2;
+
+	hdmi_audio_infoframe_pack_payload(frame, sdp->db);
+
+	/* Return size =  frame length + four HB for sdp_header */
+	return frame->length + 4;
+}
+EXPORT_SYMBOL(hdmi_audio_infoframe_pack_for_dp);
+
+/**
  * hdmi_vendor_infoframe_init() - initialize an HDMI vendor infoframe
  * @frame: HDMI vendor infoframe
  *
@@ -499,7 +543,7 @@ int hdmi_vendor_infoframe_init(struct hdmi_vendor_infoframe *frame)
 	 * value
 	 */
 	frame->s3d_struct = HDMI_3D_STRUCTURE_INVALID;
-	frame->length = 4;
+	frame->length = HDMI_VENDOR_INFOFRAME_SIZE;
 
 	return 0;
 }
@@ -650,6 +694,150 @@ hdmi_vendor_any_infoframe_check_only(const union hdmi_vendor_any_infoframe *fram
 	return 0;
 }
 
+/**
+ * hdmi_drm_infoframe_init() - initialize an HDMI Dynaminc Range and
+ * mastering infoframe
+ * @frame: HDMI DRM infoframe
+ *
+ * Returns 0 on success or a negative error code on failure.
+ */
+int hdmi_drm_infoframe_init(struct hdmi_drm_infoframe *frame)
+{
+	memset(frame, 0, sizeof(*frame));
+
+	frame->type = HDMI_INFOFRAME_TYPE_DRM;
+	frame->version = 1;
+	frame->length = HDMI_DRM_INFOFRAME_SIZE;
+
+	return 0;
+}
+EXPORT_SYMBOL(hdmi_drm_infoframe_init);
+
+static int hdmi_drm_infoframe_check_only(const struct hdmi_drm_infoframe *frame)
+{
+	if (frame->type != HDMI_INFOFRAME_TYPE_DRM ||
+	    frame->version != 1)
+		return -EINVAL;
+
+	if (frame->length != HDMI_DRM_INFOFRAME_SIZE)
+		return -EINVAL;
+
+	return 0;
+}
+
+/**
+ * hdmi_drm_infoframe_check() - check a HDMI DRM infoframe
+ * @frame: HDMI DRM infoframe
+ *
+ * Validates that the infoframe is consistent.
+ * Returns 0 on success or a negative error code on failure.
+ */
+int hdmi_drm_infoframe_check(struct hdmi_drm_infoframe *frame)
+{
+	return hdmi_drm_infoframe_check_only(frame);
+}
+EXPORT_SYMBOL(hdmi_drm_infoframe_check);
+
+/**
+ * hdmi_drm_infoframe_pack_only() - write HDMI DRM infoframe to binary buffer
+ * @frame: HDMI DRM infoframe
+ * @buffer: destination buffer
+ * @size: size of buffer
+ *
+ * Packs the information contained in the @frame structure into a binary
+ * representation that can be written into the corresponding controller
+ * registers. Also computes the checksum as required by section 5.3.5 of
+ * the HDMI 1.4 specification.
+ *
+ * Returns the number of bytes packed into the binary buffer or a negative
+ * error code on failure.
+ */
+ssize_t hdmi_drm_infoframe_pack_only(const struct hdmi_drm_infoframe *frame,
+				     void *buffer, size_t size)
+{
+	u8 *ptr = buffer;
+	size_t length;
+	int i;
+
+	length = HDMI_INFOFRAME_HEADER_SIZE + frame->length;
+
+	if (size < length)
+		return -ENOSPC;
+
+	memset(buffer, 0, size);
+
+	ptr[0] = frame->type;
+	ptr[1] = frame->version;
+	ptr[2] = frame->length;
+	ptr[3] = 0; /* checksum */
+
+	/* start infoframe payload */
+	ptr += HDMI_INFOFRAME_HEADER_SIZE;
+
+	*ptr++ = frame->eotf;
+	*ptr++ = frame->metadata_type;
+
+	for (i = 0; i < 3; i++) {
+		*ptr++ = frame->display_primaries[i].x;
+		*ptr++ = frame->display_primaries[i].x >> 8;
+		*ptr++ = frame->display_primaries[i].y;
+		*ptr++ = frame->display_primaries[i].y >> 8;
+	}
+
+	*ptr++ = frame->white_point.x;
+	*ptr++ = frame->white_point.x >> 8;
+
+	*ptr++ = frame->white_point.y;
+	*ptr++ = frame->white_point.y >> 8;
+
+	*ptr++ = frame->max_display_mastering_luminance;
+	*ptr++ = frame->max_display_mastering_luminance >> 8;
+
+	*ptr++ = frame->min_display_mastering_luminance;
+	*ptr++ = frame->min_display_mastering_luminance >> 8;
+
+	*ptr++ = frame->max_cll;
+	*ptr++ = frame->max_cll >> 8;
+
+	*ptr++ = frame->max_fall;
+	*ptr++ = frame->max_fall >> 8;
+
+	hdmi_infoframe_set_checksum(buffer, length);
+
+	return length;
+}
+EXPORT_SYMBOL(hdmi_drm_infoframe_pack_only);
+
+/**
+ * hdmi_drm_infoframe_pack() - check a HDMI DRM infoframe,
+ *                             and write it to binary buffer
+ * @frame: HDMI DRM infoframe
+ * @buffer: destination buffer
+ * @size: size of buffer
+ *
+ * Validates that the infoframe is consistent and updates derived fields
+ * (eg. length) based on other fields, after which it packs the information
+ * contained in the @frame structure into a binary representation that
+ * can be written into the corresponding controller registers. This function
+ * also computes the checksum as required by section 5.3.5 of the HDMI 1.4
+ * specification.
+ *
+ * Returns the number of bytes packed into the binary buffer or a negative
+ * error code on failure.
+ */
+ssize_t hdmi_drm_infoframe_pack(struct hdmi_drm_infoframe *frame,
+				void *buffer, size_t size)
+{
+	int ret;
+
+	ret = hdmi_drm_infoframe_check(frame);
+	if (ret)
+		return ret;
+
+	return hdmi_drm_infoframe_pack_only(frame, buffer, size);
+}
+EXPORT_SYMBOL(hdmi_drm_infoframe_pack);
+
 /*
  * hdmi_vendor_any_infoframe_check() - check a vendor infoframe
  */
@@ -707,34 +895,6 @@ hdmi_vendor_any_infoframe_pack(union hdmi_vendor_any_infoframe *frame,
 }
 
 /**
- * hdmi_infoframe_check() - check a HDMI infoframe
- * @frame: HDMI infoframe
- *
- * Validates that the infoframe is consistent and updates derived fields
- * (eg. length) based on other fields.
- *
- * Returns 0 on success or a negative error code on failure.
- */
-int
-hdmi_infoframe_check(union hdmi_infoframe *frame)
-{
-	switch (frame->any.type) {
-	case HDMI_INFOFRAME_TYPE_AVI:
-		return hdmi_avi_infoframe_check(&frame->avi);
-	case HDMI_INFOFRAME_TYPE_SPD:
-		return hdmi_spd_infoframe_check(&frame->spd);
-	case HDMI_INFOFRAME_TYPE_AUDIO:
-		return hdmi_audio_infoframe_check(&frame->audio);
-	case HDMI_INFOFRAME_TYPE_VENDOR:
-		return hdmi_vendor_any_infoframe_check(&frame->vendor);
-	default:
-		WARN(1, "Bad infoframe type %d\n", frame->any.type);
-		return -EINVAL;
-	}
-}
-EXPORT_SYMBOL(hdmi_infoframe_check);
-
-/**
  * hdmi_infoframe_pack_only() - write a HDMI infoframe to binary buffer
  * @frame: HDMI infoframe
  * @buffer: destination buffer
@@ -758,6 +918,10 @@ hdmi_infoframe_pack_only(const union hdmi_infoframe *frame, void *buffer, size_t
 		length = hdmi_avi_infoframe_pack_only(&frame->avi,
 						      buffer, size);
 		break;
+	case HDMI_INFOFRAME_TYPE_DRM:
+		length = hdmi_drm_infoframe_pack_only(&frame->drm,
+						      buffer, size);
+		break;
 	case HDMI_INFOFRAME_TYPE_SPD:
 		length = hdmi_spd_infoframe_pack_only(&frame->spd,
 						      buffer, size);
@@ -806,6 +970,9 @@ hdmi_infoframe_pack(union hdmi_infoframe *frame,
 	case HDMI_INFOFRAME_TYPE_AVI:
 		length = hdmi_avi_infoframe_pack(&frame->avi, buffer, size);
 		break;
+	case HDMI_INFOFRAME_TYPE_DRM:
+		length = hdmi_drm_infoframe_pack(&frame->drm, buffer, size);
+		break;
 	case HDMI_INFOFRAME_TYPE_SPD:
 		length = hdmi_spd_infoframe_pack(&frame->spd, buffer, size);
 		break;
@@ -838,6 +1005,8 @@ static const char *hdmi_infoframe_type_get_name(enum hdmi_infoframe_type type)
 		return "Source Product Description (SPD)";
 	case HDMI_INFOFRAME_TYPE_AUDIO:
 		return "Audio";
+	case HDMI_INFOFRAME_TYPE_DRM:
+		return "Dynamic Range and Mastering";
 	}
 	return "Reserved";
 }
@@ -1038,12 +1207,6 @@ hdmi_content_type_get_name(enum hdmi_content_type content_type)
 	return "Invalid";
 }
 
-/**
- * hdmi_avi_infoframe_log() - log info of HDMI AVI infoframe
- * @level: logging level
- * @dev: device
- * @frame: HDMI AVI infoframe
- */
 static void hdmi_avi_infoframe_log(const char *level,
 				   struct device *dev,
 				   const struct hdmi_avi_infoframe *frame)
@@ -1115,27 +1278,15 @@ static const char *hdmi_spd_sdi_get_name(enum hdmi_spd_sdi sdi)
 	return "Reserved";
 }
 
-/**
- * hdmi_spd_infoframe_log() - log info of HDMI SPD infoframe
- * @level: logging level
- * @dev: device
- * @frame: HDMI SPD infoframe
- */
 static void hdmi_spd_infoframe_log(const char *level,
 				   struct device *dev,
 				   const struct hdmi_spd_infoframe *frame)
 {
-	u8 buf[17];
-
 	hdmi_infoframe_log_header(level, dev,
 				  (const struct hdmi_any_infoframe *)frame);
 
-	memset(buf, 0, sizeof(buf));
-
-	strncpy(buf, frame->vendor, 8);
-	hdmi_log("    vendor: %s\n", buf);
-	strncpy(buf, frame->product, 16);
-	hdmi_log("    product: %s\n", buf);
+	hdmi_log("    vendor: %.8s\n", frame->vendor);
+	hdmi_log("    product: %.16s\n", frame->product);
 	hdmi_log("    source device information: %s (0x%x)\n",
 		hdmi_spd_sdi_get_name(frame->sdi), frame->sdi);
 }
@@ -1251,12 +1402,6 @@ hdmi_audio_coding_type_ext_get_name(enum hdmi_audio_coding_type_ext ctx)
 	return "Reserved";
 }
 
-/**
- * hdmi_audio_infoframe_log() - log info of HDMI AUDIO infoframe
- * @level: logging level
- * @dev: device
- * @frame: HDMI AUDIO infoframe
- */
 static void hdmi_audio_infoframe_log(const char *level,
 				     struct device *dev,
 				     const struct hdmi_audio_infoframe *frame)
@@ -1284,6 +1429,34 @@ static void hdmi_audio_infoframe_log(const char *level,
 			frame->downmix_inhibit ? "Yes" : "No");
 }
 
+static void hdmi_drm_infoframe_log(const char *level,
+				   struct device *dev,
+				   const struct hdmi_drm_infoframe *frame)
+{
+	int i;
+
+	hdmi_infoframe_log_header(level, dev,
+				  (struct hdmi_any_infoframe *)frame);
+	hdmi_log("length: %d\n", frame->length);
+	hdmi_log("metadata type: %d\n", frame->metadata_type);
+	hdmi_log("eotf: %d\n", frame->eotf);
+	for (i = 0; i < 3; i++) {
+		hdmi_log("x[%d]: %d\n", i, frame->display_primaries[i].x);
+		hdmi_log("y[%d]: %d\n", i, frame->display_primaries[i].y);
+	}
+
+	hdmi_log("white point x: %d\n", frame->white_point.x);
+	hdmi_log("white point y: %d\n", frame->white_point.y);
+
+	hdmi_log("max_display_mastering_luminance: %d\n",
+		 frame->max_display_mastering_luminance);
+	hdmi_log("min_display_mastering_luminance: %d\n",
+		 frame->min_display_mastering_luminance);
+
+	hdmi_log("max_cll: %d\n", frame->max_cll);
+	hdmi_log("max_fall: %d\n", frame->max_fall);
+}
+
 static const char *
 hdmi_3d_structure_get_name(enum hdmi_3d_structure s3d_struct)
 {
@@ -1313,12 +1486,6 @@ hdmi_3d_structure_get_name(enum hdmi_3d_structure s3d_struct)
 	return "Reserved";
 }
 
-/**
- * hdmi_vendor_infoframe_log() - log info of HDMI VENDOR infoframe
- * @level: logging level
- * @dev: device
- * @frame: HDMI VENDOR infoframe
- */
 static void
 hdmi_vendor_any_infoframe_log(const char *level,
 			      struct device *dev,
@@ -1372,6 +1539,9 @@ void hdmi_infoframe_log(const char *level,
 	case HDMI_INFOFRAME_TYPE_VENDOR:
 		hdmi_vendor_any_infoframe_log(level, dev, &frame->vendor);
 		break;
+	case HDMI_INFOFRAME_TYPE_DRM:
+		hdmi_drm_infoframe_log(level, dev, &frame->drm);
+		break;
 	}
 }
 EXPORT_SYMBOL(hdmi_infoframe_log);
@@ -1393,7 +1563,6 @@ static int hdmi_avi_infoframe_unpack(struct hdmi_avi_infoframe *frame,
 				     const void *buffer, size_t size)
 {
 	const u8 *ptr = buffer;
-	int ret;
 
 	if (size < HDMI_INFOFRAME_SIZE(AVI))
 		return -EINVAL;
@@ -1406,9 +1575,7 @@ static int hdmi_avi_infoframe_unpack(struct hdmi_avi_infoframe *frame,
 	if (hdmi_infoframe_checksum(buffer, HDMI_INFOFRAME_SIZE(AVI)) != 0)
 		return -EINVAL;
 
-	ret = hdmi_avi_infoframe_init(frame);
-	if (ret)
-		return ret;
+	hdmi_avi_infoframe_init(frame);
 
 	ptr += HDMI_INFOFRAME_HEADER_SIZE;
 
@@ -1416,12 +1583,12 @@ static int hdmi_avi_infoframe_unpack(struct hdmi_avi_infoframe *frame,
 	if (ptr[0] & 0x10)
 		frame->active_aspect = ptr[1] & 0xf;
 	if (ptr[0] & 0x8) {
-		frame->top_bar = (ptr[5] << 8) + ptr[6];
-		frame->bottom_bar = (ptr[7] << 8) + ptr[8];
+		frame->top_bar = (ptr[6] << 8) | ptr[5];
+		frame->bottom_bar = (ptr[8] << 8) | ptr[7];
 	}
 	if (ptr[0] & 0x4) {
-		frame->left_bar = (ptr[9] << 8) + ptr[10];
-		frame->right_bar = (ptr[11] << 8) + ptr[12];
+		frame->left_bar = (ptr[10] << 8) | ptr[9];
+		frame->right_bar = (ptr[12] << 8) | ptr[11];
 	}
 	frame->scan_mode = ptr[0] & 0x3;
 
@@ -1535,7 +1702,8 @@ static int hdmi_audio_infoframe_unpack(struct hdmi_audio_infoframe *frame,
 }
 
 /**
- * hdmi_vendor_infoframe_unpack() - unpack binary buffer to a HDMI vendor infoframe
+ * hdmi_vendor_any_infoframe_unpack() - unpack binary buffer to a HDMI
+ * 	vendor infoframe
  * @frame: HDMI Vendor infoframe
  * @buffer: source buffer
  * @size: size of buffer
@@ -1615,6 +1783,97 @@ hdmi_vendor_any_infoframe_unpack(union hdmi_vendor_any_infoframe *frame,
 }
 
 /**
+ * hdmi_drm_infoframe_unpack_only() - unpack binary buffer of CTA-861-G DRM
+ *                                    infoframe DataBytes to a HDMI DRM
+ *                                    infoframe
+ * @frame: HDMI DRM infoframe
+ * @buffer: source buffer
+ * @size: size of buffer
+ *
+ * Unpacks CTA-861-G DRM infoframe DataBytes contained in the binary @buffer
+ * into a structured @frame of the HDMI Dynamic Range and Mastering (DRM)
+ * infoframe.
+ *
+ * Returns 0 on success or a negative error code on failure.
+ */
+int hdmi_drm_infoframe_unpack_only(struct hdmi_drm_infoframe *frame,
+				   const void *buffer, size_t size)
+{
+	const u8 *ptr = buffer;
+	const u8 *temp;
+	u8 x_lsb, x_msb;
+	u8 y_lsb, y_msb;
+	int ret;
+	int i;
+
+	if (size < HDMI_DRM_INFOFRAME_SIZE)
+		return -EINVAL;
+
+	ret = hdmi_drm_infoframe_init(frame);
+	if (ret)
+		return ret;
+
+	frame->eotf = ptr[0] & 0x7;
+	frame->metadata_type = ptr[1] & 0x7;
+
+	temp = ptr + 2;
+	for (i = 0; i < 3; i++) {
+		x_lsb = *temp++;
+		x_msb = *temp++;
+		frame->display_primaries[i].x = (x_msb << 8) | x_lsb;
+		y_lsb = *temp++;
+		y_msb = *temp++;
+		frame->display_primaries[i].y = (y_msb << 8) | y_lsb;
+	}
+
+	frame->white_point.x = (ptr[15] << 8) | ptr[14];
+	frame->white_point.y = (ptr[17] << 8) | ptr[16];
+
+	frame->max_display_mastering_luminance = (ptr[19] << 8) | ptr[18];
+	frame->min_display_mastering_luminance = (ptr[21] << 8) | ptr[20];
+	frame->max_cll = (ptr[23] << 8) | ptr[22];
+	frame->max_fall = (ptr[25] << 8) | ptr[24];
+
+	return 0;
+}
+EXPORT_SYMBOL(hdmi_drm_infoframe_unpack_only);
+
+/**
+ * hdmi_drm_infoframe_unpack() - unpack binary buffer to a HDMI DRM infoframe
+ * @frame: HDMI DRM infoframe
+ * @buffer: source buffer
+ * @size: size of buffer
+ *
+ * Unpacks the CTA-861-G DRM infoframe contained in the binary @buffer into
+ * a structured @frame of the HDMI Dynamic Range and Mastering (DRM)
+ * infoframe. It also verifies the checksum as required by section 5.3.5 of
+ * the HDMI 1.4 specification.
+ *
+ * Returns 0 on success or a negative error code on failure.
+ */
+static int hdmi_drm_infoframe_unpack(struct hdmi_drm_infoframe *frame,
+				     const void *buffer, size_t size)
+{
+	const u8 *ptr = buffer;
+	int ret;
+
+	if (size < HDMI_INFOFRAME_SIZE(DRM))
+		return -EINVAL;
+
+	if (ptr[0] != HDMI_INFOFRAME_TYPE_DRM ||
+	    ptr[1] != 1 ||
+	    ptr[2] != HDMI_DRM_INFOFRAME_SIZE)
+		return -EINVAL;
+
+	if (hdmi_infoframe_checksum(buffer, HDMI_INFOFRAME_SIZE(DRM)) != 0)
+		return -EINVAL;
+
+	ret = hdmi_drm_infoframe_unpack_only(frame, ptr + HDMI_INFOFRAME_HEADER_SIZE,
+					     size - HDMI_INFOFRAME_HEADER_SIZE);
+	return ret;
+}
+
+/**
  * hdmi_infoframe_unpack() - unpack binary buffer to a HDMI infoframe
  * @frame: HDMI infoframe
  * @buffer: source buffer
@@ -1640,6 +1899,9 @@ int hdmi_infoframe_unpack(union hdmi_infoframe *frame,
 	case HDMI_INFOFRAME_TYPE_AVI:
 		ret = hdmi_avi_infoframe_unpack(&frame->avi, buffer, size);
 		break;
+	case HDMI_INFOFRAME_TYPE_DRM:
+		ret = hdmi_drm_infoframe_unpack(&frame->drm, buffer, size);
+		break;
 	case HDMI_INFOFRAME_TYPE_SPD:
 		ret = hdmi_spd_infoframe_unpack(&frame->spd, buffer, size);
 		break;