Adding upstream version 5.10.209.upstream/5.10.209upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 767 insertions, 0 deletions

diff --git a/sound/pci/hda/hda_eld.c b/sound/pci/hda/hda_eld.c
new file mode 100644
index 000000000..136477ed4
--- /dev/null
+++ b/sound/pci/hda/hda_eld.c
@@ -0,0 +1,767 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Generic routines and proc interface for ELD(EDID Like Data) information
+ *
+ * Copyright(c) 2008 Intel Corporation.
+ * Copyright (c) 2013 Anssi Hannula <anssi.hannula@iki.fi>
+ *
+ * Authors:
+ * 		Wu Fengguang <wfg@linux.intel.com>
+ */
+
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <sound/core.h>
+#include <asm/unaligned.h>
+#include <sound/hda_chmap.h>
+#include <sound/hda_codec.h>
+#include "hda_local.h"
+
+enum eld_versions {
+	ELD_VER_CEA_861D	= 2,
+	ELD_VER_PARTIAL		= 31,
+};
+
+enum cea_edid_versions {
+	CEA_EDID_VER_NONE	= 0,
+	CEA_EDID_VER_CEA861	= 1,
+	CEA_EDID_VER_CEA861A	= 2,
+	CEA_EDID_VER_CEA861BCD	= 3,
+	CEA_EDID_VER_RESERVED	= 4,
+};
+
+static const char * const eld_connection_type_names[4] = {
+	"HDMI",
+	"DisplayPort",
+	"2-reserved",
+	"3-reserved"
+};
+
+enum cea_audio_coding_types {
+	AUDIO_CODING_TYPE_REF_STREAM_HEADER	=  0,
+	AUDIO_CODING_TYPE_LPCM			=  1,
+	AUDIO_CODING_TYPE_AC3			=  2,
+	AUDIO_CODING_TYPE_MPEG1			=  3,
+	AUDIO_CODING_TYPE_MP3			=  4,
+	AUDIO_CODING_TYPE_MPEG2			=  5,
+	AUDIO_CODING_TYPE_AACLC			=  6,
+	AUDIO_CODING_TYPE_DTS			=  7,
+	AUDIO_CODING_TYPE_ATRAC			=  8,
+	AUDIO_CODING_TYPE_SACD			=  9,
+	AUDIO_CODING_TYPE_EAC3			= 10,
+	AUDIO_CODING_TYPE_DTS_HD		= 11,
+	AUDIO_CODING_TYPE_MLP			= 12,
+	AUDIO_CODING_TYPE_DST			= 13,
+	AUDIO_CODING_TYPE_WMAPRO		= 14,
+	AUDIO_CODING_TYPE_REF_CXT		= 15,
+	/* also include valid xtypes below */
+	AUDIO_CODING_TYPE_HE_AAC		= 15,
+	AUDIO_CODING_TYPE_HE_AAC2		= 16,
+	AUDIO_CODING_TYPE_MPEG_SURROUND		= 17,
+};
+
+enum cea_audio_coding_xtypes {
+	AUDIO_CODING_XTYPE_HE_REF_CT		= 0,
+	AUDIO_CODING_XTYPE_HE_AAC		= 1,
+	AUDIO_CODING_XTYPE_HE_AAC2		= 2,
+	AUDIO_CODING_XTYPE_MPEG_SURROUND	= 3,
+	AUDIO_CODING_XTYPE_FIRST_RESERVED	= 4,
+};
+
+static const char * const cea_audio_coding_type_names[] = {
+	/*  0 */ "undefined",
+	/*  1 */ "LPCM",
+	/*  2 */ "AC-3",
+	/*  3 */ "MPEG1",
+	/*  4 */ "MP3",
+	/*  5 */ "MPEG2",
+	/*  6 */ "AAC-LC",
+	/*  7 */ "DTS",
+	/*  8 */ "ATRAC",
+	/*  9 */ "DSD (One Bit Audio)",
+	/* 10 */ "E-AC-3/DD+ (Dolby Digital Plus)",
+	/* 11 */ "DTS-HD",
+	/* 12 */ "MLP (Dolby TrueHD)",
+	/* 13 */ "DST",
+	/* 14 */ "WMAPro",
+	/* 15 */ "HE-AAC",
+	/* 16 */ "HE-AACv2",
+	/* 17 */ "MPEG Surround",
+};
+
+/*
+ * The following two lists are shared between
+ * 	- HDMI audio InfoFrame (source to sink)
+ * 	- CEA E-EDID Extension (sink to source)
+ */
+
+/*
+ * SS1:SS0 index => sample size
+ */
+static const int cea_sample_sizes[4] = {
+	0,	 		/* 0: Refer to Stream Header */
+	AC_SUPPCM_BITS_16,	/* 1: 16 bits */
+	AC_SUPPCM_BITS_20,	/* 2: 20 bits */
+	AC_SUPPCM_BITS_24,	/* 3: 24 bits */
+};
+
+/*
+ * SF2:SF1:SF0 index => sampling frequency
+ */
+static const int cea_sampling_frequencies[8] = {
+	0,			/* 0: Refer to Stream Header */
+	SNDRV_PCM_RATE_32000,	/* 1:  32000Hz */
+	SNDRV_PCM_RATE_44100,	/* 2:  44100Hz */
+	SNDRV_PCM_RATE_48000,	/* 3:  48000Hz */
+	SNDRV_PCM_RATE_88200,	/* 4:  88200Hz */
+	SNDRV_PCM_RATE_96000,	/* 5:  96000Hz */
+	SNDRV_PCM_RATE_176400,	/* 6: 176400Hz */
+	SNDRV_PCM_RATE_192000,	/* 7: 192000Hz */
+};
+
+static unsigned int hdmi_get_eld_data(struct hda_codec *codec, hda_nid_t nid,
+					int byte_index)
+{
+	unsigned int val;
+
+	val = snd_hda_codec_read(codec, nid, 0,
+					AC_VERB_GET_HDMI_ELDD, byte_index);
+#ifdef BE_PARANOID
+	codec_info(codec, "HDMI: ELD data byte %d: 0x%x\n", byte_index, val);
+#endif
+	return val;
+}
+
+#define GRAB_BITS(buf, byte, lowbit, bits) 		\
+({							\
+	BUILD_BUG_ON(lowbit > 7);			\
+	BUILD_BUG_ON(bits > 8);				\
+	BUILD_BUG_ON(bits <= 0);			\
+							\
+	(buf[byte] >> (lowbit)) & ((1 << (bits)) - 1);	\
+})
+
+static void hdmi_update_short_audio_desc(struct hda_codec *codec,
+					 struct cea_sad *a,
+					 const unsigned char *buf)
+{
+	int i;
+	int val;
+
+	val = GRAB_BITS(buf, 1, 0, 7);
+	a->rates = 0;
+	for (i = 0; i < 7; i++)
+		if (val & (1 << i))
+			a->rates |= cea_sampling_frequencies[i + 1];
+
+	a->channels = GRAB_BITS(buf, 0, 0, 3);
+	a->channels++;
+
+	a->sample_bits = 0;
+	a->max_bitrate = 0;
+
+	a->format = GRAB_BITS(buf, 0, 3, 4);
+	switch (a->format) {
+	case AUDIO_CODING_TYPE_REF_STREAM_HEADER:
+		codec_info(codec, "HDMI: audio coding type 0 not expected\n");
+		break;
+
+	case AUDIO_CODING_TYPE_LPCM:
+		val = GRAB_BITS(buf, 2, 0, 3);
+		for (i = 0; i < 3; i++)
+			if (val & (1 << i))
+				a->sample_bits |= cea_sample_sizes[i + 1];
+		break;
+
+	case AUDIO_CODING_TYPE_AC3:
+	case AUDIO_CODING_TYPE_MPEG1:
+	case AUDIO_CODING_TYPE_MP3:
+	case AUDIO_CODING_TYPE_MPEG2:
+	case AUDIO_CODING_TYPE_AACLC:
+	case AUDIO_CODING_TYPE_DTS:
+	case AUDIO_CODING_TYPE_ATRAC:
+		a->max_bitrate = GRAB_BITS(buf, 2, 0, 8);
+		a->max_bitrate *= 8000;
+		break;
+
+	case AUDIO_CODING_TYPE_SACD:
+		break;
+
+	case AUDIO_CODING_TYPE_EAC3:
+		break;
+
+	case AUDIO_CODING_TYPE_DTS_HD:
+		break;
+
+	case AUDIO_CODING_TYPE_MLP:
+		break;
+
+	case AUDIO_CODING_TYPE_DST:
+		break;
+
+	case AUDIO_CODING_TYPE_WMAPRO:
+		a->profile = GRAB_BITS(buf, 2, 0, 3);
+		break;
+
+	case AUDIO_CODING_TYPE_REF_CXT:
+		a->format = GRAB_BITS(buf, 2, 3, 5);
+		if (a->format == AUDIO_CODING_XTYPE_HE_REF_CT ||
+		    a->format >= AUDIO_CODING_XTYPE_FIRST_RESERVED) {
+			codec_info(codec,
+				   "HDMI: audio coding xtype %d not expected\n",
+				   a->format);
+			a->format = 0;
+		} else
+			a->format += AUDIO_CODING_TYPE_HE_AAC -
+				     AUDIO_CODING_XTYPE_HE_AAC;
+		break;
+	}
+}
+
+/*
+ * Be careful, ELD buf could be totally rubbish!
+ */
+int snd_hdmi_parse_eld(struct hda_codec *codec, struct parsed_hdmi_eld *e,
+			  const unsigned char *buf, int size)
+{
+	int mnl;
+	int i;
+
+	memset(e, 0, sizeof(*e));
+	e->eld_ver = GRAB_BITS(buf, 0, 3, 5);
+	if (e->eld_ver != ELD_VER_CEA_861D &&
+	    e->eld_ver != ELD_VER_PARTIAL) {
+		codec_info(codec, "HDMI: Unknown ELD version %d\n", e->eld_ver);
+		goto out_fail;
+	}
+
+	e->baseline_len = GRAB_BITS(buf, 2, 0, 8);
+	mnl		= GRAB_BITS(buf, 4, 0, 5);
+	e->cea_edid_ver	= GRAB_BITS(buf, 4, 5, 3);
+
+	e->support_hdcp	= GRAB_BITS(buf, 5, 0, 1);
+	e->support_ai	= GRAB_BITS(buf, 5, 1, 1);
+	e->conn_type	= GRAB_BITS(buf, 5, 2, 2);
+	e->sad_count	= GRAB_BITS(buf, 5, 4, 4);
+
+	e->aud_synch_delay = GRAB_BITS(buf, 6, 0, 8) * 2;
+	e->spk_alloc	= GRAB_BITS(buf, 7, 0, 7);
+
+	e->port_id	  = get_unaligned_le64(buf + 8);
+
+	/* not specified, but the spec's tendency is little endian */
+	e->manufacture_id = get_unaligned_le16(buf + 16);
+	e->product_id	  = get_unaligned_le16(buf + 18);
+
+	if (mnl > ELD_MAX_MNL) {
+		codec_info(codec, "HDMI: MNL is reserved value %d\n", mnl);
+		goto out_fail;
+	} else if (ELD_FIXED_BYTES + mnl > size) {
+		codec_info(codec, "HDMI: out of range MNL %d\n", mnl);
+		goto out_fail;
+	} else
+		strlcpy(e->monitor_name, buf + ELD_FIXED_BYTES, mnl + 1);
+
+	for (i = 0; i < e->sad_count; i++) {
+		if (ELD_FIXED_BYTES + mnl + 3 * (i + 1) > size) {
+			codec_info(codec, "HDMI: out of range SAD %d\n", i);
+			goto out_fail;
+		}
+		hdmi_update_short_audio_desc(codec, e->sad + i,
+					buf + ELD_FIXED_BYTES + mnl + 3 * i);
+	}
+
+	/*
+	 * HDMI sink's ELD info cannot always be retrieved for now, e.g.
+	 * in console or for audio devices. Assume the highest speakers
+	 * configuration, to _not_ prohibit multi-channel audio playback.
+	 */
+	if (!e->spk_alloc)
+		e->spk_alloc = 0xffff;
+
+	return 0;
+
+out_fail:
+	return -EINVAL;
+}
+
+int snd_hdmi_get_eld_size(struct hda_codec *codec, hda_nid_t nid)
+{
+	return snd_hda_codec_read(codec, nid, 0, AC_VERB_GET_HDMI_DIP_SIZE,
+						 AC_DIPSIZE_ELD_BUF);
+}
+
+int snd_hdmi_get_eld(struct hda_codec *codec, hda_nid_t nid,
+		     unsigned char *buf, int *eld_size)
+{
+	int i;
+	int ret = 0;
+	int size;
+
+	/*
+	 * ELD size is initialized to zero in caller function. If no errors and
+	 * ELD is valid, actual eld_size is assigned.
+	 */
+
+	size = snd_hdmi_get_eld_size(codec, nid);
+	if (size == 0) {
+		/* wfg: workaround for ASUS P5E-VM HDMI board */
+		codec_info(codec, "HDMI: ELD buf size is 0, force 128\n");
+		size = 128;
+	}
+	if (size < ELD_FIXED_BYTES || size > ELD_MAX_SIZE) {
+		codec_info(codec, "HDMI: invalid ELD buf size %d\n", size);
+		return -ERANGE;
+	}
+
+	/* set ELD buffer */
+	for (i = 0; i < size; i++) {
+		unsigned int val = hdmi_get_eld_data(codec, nid, i);
+		/*
+		 * Graphics driver might be writing to ELD buffer right now.
+		 * Just abort. The caller will repoll after a while.
+		 */
+		if (!(val & AC_ELDD_ELD_VALID)) {
+			codec_info(codec, "HDMI: invalid ELD data byte %d\n", i);
+			ret = -EINVAL;
+			goto error;
+		}
+		val &= AC_ELDD_ELD_DATA;
+		/*
+		 * The first byte cannot be zero. This can happen on some DVI
+		 * connections. Some Intel chips may also need some 250ms delay
+		 * to return non-zero ELD data, even when the graphics driver
+		 * correctly writes ELD content before setting ELD_valid bit.
+		 */
+		if (!val && !i) {
+			codec_dbg(codec, "HDMI: 0 ELD data\n");
+			ret = -EINVAL;
+			goto error;
+		}
+		buf[i] = val;
+	}
+
+	*eld_size = size;
+error:
+	return ret;
+}
+
+/*
+ * SNDRV_PCM_RATE_* and AC_PAR_PCM values don't match, print correct rates with
+ * hdmi-specific routine.
+ */
+static void hdmi_print_pcm_rates(int pcm, char *buf, int buflen)
+{
+	static const unsigned int alsa_rates[] = {
+		5512, 8000, 11025, 16000, 22050, 32000, 44100, 48000, 64000,
+		88200, 96000, 176400, 192000, 384000
+	};
+	int i, j;
+
+	for (i = 0, j = 0; i < ARRAY_SIZE(alsa_rates); i++)
+		if (pcm & (1 << i))
+			j += scnprintf(buf + j, buflen - j,  " %d",
+				alsa_rates[i]);
+
+	buf[j] = '\0'; /* necessary when j == 0 */
+}
+
+#define SND_PRINT_RATES_ADVISED_BUFSIZE	80
+
+static void hdmi_show_short_audio_desc(struct hda_codec *codec,
+				       struct cea_sad *a)
+{
+	char buf[SND_PRINT_RATES_ADVISED_BUFSIZE];
+	char buf2[8 + SND_PRINT_BITS_ADVISED_BUFSIZE] = ", bits =";
+
+	if (!a->format)
+		return;
+
+	hdmi_print_pcm_rates(a->rates, buf, sizeof(buf));
+
+	if (a->format == AUDIO_CODING_TYPE_LPCM)
+		snd_print_pcm_bits(a->sample_bits, buf2 + 8, sizeof(buf2) - 8);
+	else if (a->max_bitrate)
+		snprintf(buf2, sizeof(buf2),
+				", max bitrate = %d", a->max_bitrate);
+	else
+		buf2[0] = '\0';
+
+	codec_dbg(codec,
+		  "HDMI: supports coding type %s: channels = %d, rates =%s%s\n",
+		  cea_audio_coding_type_names[a->format],
+		  a->channels, buf, buf2);
+}
+
+void snd_hdmi_show_eld(struct hda_codec *codec, struct parsed_hdmi_eld *e)
+{
+	int i;
+
+	codec_dbg(codec, "HDMI: detected monitor %s at connection type %s\n",
+			e->monitor_name,
+			eld_connection_type_names[e->conn_type]);
+
+	if (e->spk_alloc) {
+		char buf[SND_PRINT_CHANNEL_ALLOCATION_ADVISED_BUFSIZE];
+		snd_hdac_print_channel_allocation(e->spk_alloc, buf, sizeof(buf));
+		codec_dbg(codec, "HDMI: available speakers:%s\n", buf);
+	}
+
+	for (i = 0; i < e->sad_count; i++)
+		hdmi_show_short_audio_desc(codec, e->sad + i);
+}
+
+#ifdef CONFIG_SND_PROC_FS
+
+static void hdmi_print_sad_info(int i, struct cea_sad *a,
+				struct snd_info_buffer *buffer)
+{
+	char buf[SND_PRINT_RATES_ADVISED_BUFSIZE];
+
+	snd_iprintf(buffer, "sad%d_coding_type\t[0x%x] %s\n",
+			i, a->format, cea_audio_coding_type_names[a->format]);
+	snd_iprintf(buffer, "sad%d_channels\t\t%d\n", i, a->channels);
+
+	hdmi_print_pcm_rates(a->rates, buf, sizeof(buf));
+	snd_iprintf(buffer, "sad%d_rates\t\t[0x%x]%s\n", i, a->rates, buf);
+
+	if (a->format == AUDIO_CODING_TYPE_LPCM) {
+		snd_print_pcm_bits(a->sample_bits, buf, sizeof(buf));
+		snd_iprintf(buffer, "sad%d_bits\t\t[0x%x]%s\n",
+							i, a->sample_bits, buf);
+	}
+
+	if (a->max_bitrate)
+		snd_iprintf(buffer, "sad%d_max_bitrate\t%d\n",
+							i, a->max_bitrate);
+
+	if (a->profile)
+		snd_iprintf(buffer, "sad%d_profile\t\t%d\n", i, a->profile);
+}
+
+void snd_hdmi_print_eld_info(struct hdmi_eld *eld,
+			     struct snd_info_buffer *buffer)
+{
+	struct parsed_hdmi_eld *e = &eld->info;
+	char buf[SND_PRINT_CHANNEL_ALLOCATION_ADVISED_BUFSIZE];
+	int i;
+	static const char * const eld_version_names[32] = {
+		"reserved",
+		"reserved",
+		"CEA-861D or below",
+		[3 ... 30] = "reserved",
+		[31] = "partial"
+	};
+	static const char * const cea_edid_version_names[8] = {
+		"no CEA EDID Timing Extension block present",
+		"CEA-861",
+		"CEA-861-A",
+		"CEA-861-B, C or D",
+		[4 ... 7] = "reserved"
+	};
+
+	snd_iprintf(buffer, "monitor_present\t\t%d\n", eld->monitor_present);
+	snd_iprintf(buffer, "eld_valid\t\t%d\n", eld->eld_valid);
+	if (!eld->eld_valid)
+		return;
+	snd_iprintf(buffer, "monitor_name\t\t%s\n", e->monitor_name);
+	snd_iprintf(buffer, "connection_type\t\t%s\n",
+				eld_connection_type_names[e->conn_type]);
+	snd_iprintf(buffer, "eld_version\t\t[0x%x] %s\n", e->eld_ver,
+					eld_version_names[e->eld_ver]);
+	snd_iprintf(buffer, "edid_version\t\t[0x%x] %s\n", e->cea_edid_ver,
+				cea_edid_version_names[e->cea_edid_ver]);
+	snd_iprintf(buffer, "manufacture_id\t\t0x%x\n", e->manufacture_id);
+	snd_iprintf(buffer, "product_id\t\t0x%x\n", e->product_id);
+	snd_iprintf(buffer, "port_id\t\t\t0x%llx\n", (long long)e->port_id);
+	snd_iprintf(buffer, "support_hdcp\t\t%d\n", e->support_hdcp);
+	snd_iprintf(buffer, "support_ai\t\t%d\n", e->support_ai);
+	snd_iprintf(buffer, "audio_sync_delay\t%d\n", e->aud_synch_delay);
+
+	snd_hdac_print_channel_allocation(e->spk_alloc, buf, sizeof(buf));
+	snd_iprintf(buffer, "speakers\t\t[0x%x]%s\n", e->spk_alloc, buf);
+
+	snd_iprintf(buffer, "sad_count\t\t%d\n", e->sad_count);
+
+	for (i = 0; i < e->sad_count; i++)
+		hdmi_print_sad_info(i, e->sad + i, buffer);
+}
+
+void snd_hdmi_write_eld_info(struct hdmi_eld *eld,
+			     struct snd_info_buffer *buffer)
+{
+	struct parsed_hdmi_eld *e = &eld->info;
+	char line[64];
+	char name[64];
+	char *sname;
+	long long val;
+	unsigned int n;
+
+	while (!snd_info_get_line(buffer, line, sizeof(line))) {
+		if (sscanf(line, "%s %llx", name, &val) != 2)
+			continue;
+		/*
+		 * We don't allow modification to these fields:
+		 * 	monitor_name manufacture_id product_id
+		 * 	eld_version edid_version
+		 */
+		if (!strcmp(name, "monitor_present"))
+			eld->monitor_present = val;
+		else if (!strcmp(name, "eld_valid"))
+			eld->eld_valid = val;
+		else if (!strcmp(name, "connection_type"))
+			e->conn_type = val;
+		else if (!strcmp(name, "port_id"))
+			e->port_id = val;
+		else if (!strcmp(name, "support_hdcp"))
+			e->support_hdcp = val;
+		else if (!strcmp(name, "support_ai"))
+			e->support_ai = val;
+		else if (!strcmp(name, "audio_sync_delay"))
+			e->aud_synch_delay = val;
+		else if (!strcmp(name, "speakers"))
+			e->spk_alloc = val;
+		else if (!strcmp(name, "sad_count"))
+			e->sad_count = val;
+		else if (!strncmp(name, "sad", 3)) {
+			sname = name + 4;
+			n = name[3] - '0';
+			if (name[4] >= '0' && name[4] <= '9') {
+				sname++;
+				n = 10 * n + name[4] - '0';
+			}
+			if (n >= ELD_MAX_SAD)
+				continue;
+			if (!strcmp(sname, "_coding_type"))
+				e->sad[n].format = val;
+			else if (!strcmp(sname, "_channels"))
+				e->sad[n].channels = val;
+			else if (!strcmp(sname, "_rates"))
+				e->sad[n].rates = val;
+			else if (!strcmp(sname, "_bits"))
+				e->sad[n].sample_bits = val;
+			else if (!strcmp(sname, "_max_bitrate"))
+				e->sad[n].max_bitrate = val;
+			else if (!strcmp(sname, "_profile"))
+				e->sad[n].profile = val;
+			if (n >= e->sad_count)
+				e->sad_count = n + 1;
+		}
+	}
+}
+#endif /* CONFIG_SND_PROC_FS */
+
+/* update PCM info based on ELD */
+void snd_hdmi_eld_update_pcm_info(struct parsed_hdmi_eld *e,
+			      struct hda_pcm_stream *hinfo)
+{
+	u32 rates;
+	u64 formats;
+	unsigned int maxbps;
+	unsigned int channels_max;
+	int i;
+
+	/* assume basic audio support (the basic audio flag is not in ELD;
+	 * however, all audio capable sinks are required to support basic
+	 * audio) */
+	rates = SNDRV_PCM_RATE_32000 | SNDRV_PCM_RATE_44100 |
+		SNDRV_PCM_RATE_48000;
+	formats = SNDRV_PCM_FMTBIT_S16_LE;
+	maxbps = 16;
+	channels_max = 2;
+	for (i = 0; i < e->sad_count; i++) {
+		struct cea_sad *a = &e->sad[i];
+		rates |= a->rates;
+		if (a->channels > channels_max)
+			channels_max = a->channels;
+		if (a->format == AUDIO_CODING_TYPE_LPCM) {
+			if (a->sample_bits & AC_SUPPCM_BITS_20) {
+				formats |= SNDRV_PCM_FMTBIT_S32_LE;
+				if (maxbps < 20)
+					maxbps = 20;
+			}
+			if (a->sample_bits & AC_SUPPCM_BITS_24) {
+				formats |= SNDRV_PCM_FMTBIT_S32_LE;
+				if (maxbps < 24)
+					maxbps = 24;
+			}
+		}
+	}
+
+	/* restrict the parameters by the values the codec provides */
+	hinfo->rates &= rates;
+	hinfo->formats &= formats;
+	hinfo->maxbps = min(hinfo->maxbps, maxbps);
+	hinfo->channels_max = min(hinfo->channels_max, channels_max);
+}
+
+
+/* ATI/AMD specific stuff (ELD emulation) */
+
+#define ATI_VERB_SET_AUDIO_DESCRIPTOR	0x776
+#define ATI_VERB_SET_SINK_INFO_INDEX	0x780
+#define ATI_VERB_GET_SPEAKER_ALLOCATION	0xf70
+#define ATI_VERB_GET_AUDIO_DESCRIPTOR	0xf76
+#define ATI_VERB_GET_AUDIO_VIDEO_DELAY	0xf7b
+#define ATI_VERB_GET_SINK_INFO_INDEX	0xf80
+#define ATI_VERB_GET_SINK_INFO_DATA	0xf81
+
+#define ATI_SPKALLOC_SPKALLOC		0x007f
+#define ATI_SPKALLOC_TYPE_HDMI		0x0100
+#define ATI_SPKALLOC_TYPE_DISPLAYPORT	0x0200
+
+/* first three bytes are just standard SAD */
+#define ATI_AUDIODESC_CHANNELS		0x00000007
+#define ATI_AUDIODESC_RATES		0x0000ff00
+#define ATI_AUDIODESC_LPCM_STEREO_RATES	0xff000000
+
+/* in standard HDMI VSDB format */
+#define ATI_DELAY_VIDEO_LATENCY		0x000000ff
+#define ATI_DELAY_AUDIO_LATENCY		0x0000ff00
+
+enum ati_sink_info_idx {
+	ATI_INFO_IDX_MANUFACTURER_ID	= 0,
+	ATI_INFO_IDX_PRODUCT_ID		= 1,
+	ATI_INFO_IDX_SINK_DESC_LEN	= 2,
+	ATI_INFO_IDX_PORT_ID_LOW	= 3,
+	ATI_INFO_IDX_PORT_ID_HIGH	= 4,
+	ATI_INFO_IDX_SINK_DESC_FIRST	= 5,
+	ATI_INFO_IDX_SINK_DESC_LAST	= 22, /* max len 18 bytes */
+};
+
+int snd_hdmi_get_eld_ati(struct hda_codec *codec, hda_nid_t nid,
+			 unsigned char *buf, int *eld_size, bool rev3_or_later)
+{
+	int spkalloc, ati_sad, aud_synch;
+	int sink_desc_len = 0;
+	int pos, i;
+
+	/* ATI/AMD does not have ELD, emulate it */
+
+	spkalloc = snd_hda_codec_read(codec, nid, 0, ATI_VERB_GET_SPEAKER_ALLOCATION, 0);
+
+	if (spkalloc <= 0) {
+		codec_info(codec, "HDMI ATI/AMD: no speaker allocation for ELD\n");
+		return -EINVAL;
+	}
+
+	memset(buf, 0, ELD_FIXED_BYTES + ELD_MAX_MNL + ELD_MAX_SAD * 3);
+
+	/* version */
+	buf[0] = ELD_VER_CEA_861D << 3;
+
+	/* speaker allocation from EDID */
+	buf[7] = spkalloc & ATI_SPKALLOC_SPKALLOC;
+
+	/* is DisplayPort? */
+	if (spkalloc & ATI_SPKALLOC_TYPE_DISPLAYPORT)
+		buf[5] |= 0x04;
+
+	pos = ELD_FIXED_BYTES;
+
+	if (rev3_or_later) {
+		int sink_info;
+
+		snd_hda_codec_write(codec, nid, 0, ATI_VERB_SET_SINK_INFO_INDEX, ATI_INFO_IDX_PORT_ID_LOW);
+		sink_info = snd_hda_codec_read(codec, nid, 0, ATI_VERB_GET_SINK_INFO_DATA, 0);
+		put_unaligned_le32(sink_info, buf + 8);
+
+		snd_hda_codec_write(codec, nid, 0, ATI_VERB_SET_SINK_INFO_INDEX, ATI_INFO_IDX_PORT_ID_HIGH);
+		sink_info = snd_hda_codec_read(codec, nid, 0, ATI_VERB_GET_SINK_INFO_DATA, 0);
+		put_unaligned_le32(sink_info, buf + 12);
+
+		snd_hda_codec_write(codec, nid, 0, ATI_VERB_SET_SINK_INFO_INDEX, ATI_INFO_IDX_MANUFACTURER_ID);
+		sink_info = snd_hda_codec_read(codec, nid, 0, ATI_VERB_GET_SINK_INFO_DATA, 0);
+		put_unaligned_le16(sink_info, buf + 16);
+
+		snd_hda_codec_write(codec, nid, 0, ATI_VERB_SET_SINK_INFO_INDEX, ATI_INFO_IDX_PRODUCT_ID);
+		sink_info = snd_hda_codec_read(codec, nid, 0, ATI_VERB_GET_SINK_INFO_DATA, 0);
+		put_unaligned_le16(sink_info, buf + 18);
+
+		snd_hda_codec_write(codec, nid, 0, ATI_VERB_SET_SINK_INFO_INDEX, ATI_INFO_IDX_SINK_DESC_LEN);
+		sink_desc_len = snd_hda_codec_read(codec, nid, 0, ATI_VERB_GET_SINK_INFO_DATA, 0);
+
+		if (sink_desc_len > ELD_MAX_MNL) {
+			codec_info(codec, "HDMI ATI/AMD: Truncating HDMI sink description with length %d\n",
+				   sink_desc_len);
+			sink_desc_len = ELD_MAX_MNL;
+		}
+
+		buf[4] |= sink_desc_len;
+
+		for (i = 0; i < sink_desc_len; i++) {
+			snd_hda_codec_write(codec, nid, 0, ATI_VERB_SET_SINK_INFO_INDEX, ATI_INFO_IDX_SINK_DESC_FIRST + i);
+			buf[pos++] = snd_hda_codec_read(codec, nid, 0, ATI_VERB_GET_SINK_INFO_DATA, 0);
+		}
+	}
+
+	for (i = AUDIO_CODING_TYPE_LPCM; i <= AUDIO_CODING_TYPE_WMAPRO; i++) {
+		if (i == AUDIO_CODING_TYPE_SACD || i == AUDIO_CODING_TYPE_DST)
+			continue; /* not handled by ATI/AMD */
+
+		snd_hda_codec_write(codec, nid, 0, ATI_VERB_SET_AUDIO_DESCRIPTOR, i << 3);
+		ati_sad = snd_hda_codec_read(codec, nid, 0, ATI_VERB_GET_AUDIO_DESCRIPTOR, 0);
+
+		if (ati_sad <= 0)
+			continue;
+
+		if (ati_sad & ATI_AUDIODESC_RATES) {
+			/* format is supported, copy SAD as-is */
+			buf[pos++] = (ati_sad & 0x0000ff) >> 0;
+			buf[pos++] = (ati_sad & 0x00ff00) >> 8;
+			buf[pos++] = (ati_sad & 0xff0000) >> 16;
+		}
+
+		if (i == AUDIO_CODING_TYPE_LPCM
+		    && (ati_sad & ATI_AUDIODESC_LPCM_STEREO_RATES)
+		    && (ati_sad & ATI_AUDIODESC_LPCM_STEREO_RATES) >> 16 != (ati_sad & ATI_AUDIODESC_RATES)) {
+			/* for PCM there is a separate stereo rate mask */
+			buf[pos++] = ((ati_sad & 0x000000ff) & ~ATI_AUDIODESC_CHANNELS) | 0x1;
+			/* rates from the extra byte */
+			buf[pos++] = (ati_sad & 0xff000000) >> 24;
+			buf[pos++] = (ati_sad & 0x00ff0000) >> 16;
+		}
+	}
+
+	if (pos == ELD_FIXED_BYTES + sink_desc_len) {
+		codec_info(codec, "HDMI ATI/AMD: no audio descriptors for ELD\n");
+		return -EINVAL;
+	}
+
+	/*
+	 * HDMI VSDB latency format:
+	 * separately for both audio and video:
+	 *  0          field not valid or unknown latency
+	 *  [1..251]   msecs = (x-1)*2  (max 500ms with x = 251 = 0xfb)
+	 *  255        audio/video not supported
+	 *
+	 * HDA latency format:
+	 * single value indicating video latency relative to audio:
+	 *  0          unknown or 0ms
+	 *  [1..250]   msecs = x*2  (max 500ms with x = 250 = 0xfa)
+	 *  [251..255] reserved
+	 */
+	aud_synch = snd_hda_codec_read(codec, nid, 0, ATI_VERB_GET_AUDIO_VIDEO_DELAY, 0);
+	if ((aud_synch & ATI_DELAY_VIDEO_LATENCY) && (aud_synch & ATI_DELAY_AUDIO_LATENCY)) {
+		int video_latency_hdmi = (aud_synch & ATI_DELAY_VIDEO_LATENCY);
+		int audio_latency_hdmi = (aud_synch & ATI_DELAY_AUDIO_LATENCY) >> 8;
+
+		if (video_latency_hdmi <= 0xfb && audio_latency_hdmi <= 0xfb &&
+		    video_latency_hdmi > audio_latency_hdmi)
+			buf[6] = video_latency_hdmi - audio_latency_hdmi;
+		/* else unknown/invalid or 0ms or video ahead of audio, so use zero */
+	}
+
+	/* SAD count */
+	buf[5] |= ((pos - ELD_FIXED_BYTES - sink_desc_len) / 3) << 4;
+
+	/* Baseline ELD block length is 4-byte aligned */
+	pos = round_up(pos, 4);
+
+	/* Baseline ELD length (4-byte header is not counted in) */
+	buf[2] = (pos - 4) / 4;
+
+	*eld_size = pos;
+
+	return 0;
+}