ALSA: hda/hdmi: extract common interface for ELD handling

Other HDMI-related cards (e.g. hdmi-codec) are also using the ELD.
Exrtact common set of interfaces for handling the ELD.

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Link: https://patch.msgid.link/20250124-alsa-hdmi-codec-eld-v1-1-bad045cfaeac@linaro.org

1 files changed, 387 insertions, 0 deletions

diff --git a/sound/core/pcm_drm_eld.c b/sound/core/pcm_drm_eld.c
index 1cdca4d4fc9c..688eefce82fa 100644
--- a/sound/core/pcm_drm_eld.c
+++ b/sound/core/pcm_drm_eld.c
@@ -5,8 +5,10 @@
 #include <linux/bitfield.h>
 #include <linux/export.h>
 #include <linux/hdmi.h>
+#include <linux/unaligned.h>
 #include <drm/drm_edid.h>
 #include <drm/drm_eld.h>
+#include <sound/info.h>
 #include <sound/pcm.h>
 #include <sound/pcm_drm_eld.h>
 
@@ -162,3 +164,388 @@ int snd_pcm_hw_constraint_eld(struct snd_pcm_runtime *runtime, void *eld)
 	return ret;
 }
 EXPORT_SYMBOL_GPL(snd_pcm_hw_constraint_eld);
+
+#define SND_PRINT_RATES_ADVISED_BUFSIZE	80
+#define SND_PRINT_BITS_ADVISED_BUFSIZE	16
+#define SND_PRINT_CHANNEL_ALLOCATION_ADVISED_BUFSIZE 80
+
+static const char * const eld_connection_type_names[4] = {
+	"HDMI",
+	"DisplayPort",
+	"2-reserved",
+	"3-reserved"
+};
+
+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",
+};
+
+static const char * const cea_speaker_allocation_names[] = {
+	/*  0 */ "FL/FR",
+	/*  1 */ "LFE",
+	/*  2 */ "FC",
+	/*  3 */ "RL/RR",
+	/*  4 */ "RC",
+	/*  5 */ "FLC/FRC",
+	/*  6 */ "RLC/RRC",
+	/*  7 */ "FLW/FRW",
+	/*  8 */ "FLH/FRH",
+	/*  9 */ "TC",
+	/* 10 */ "FCH",
+};
+
+/*
+ * SS1:SS0 index => sample size
+ */
+static const int cea_sample_sizes[4] = {
+	0,			/* 0: Refer to Stream Header */
+	ELD_PCM_BITS_16,	/* 1: 16 bits */
+	ELD_PCM_BITS_20,	/* 2: 20 bits */
+	ELD_PCM_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 */
+};
+
+#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 device *dev,
+					 struct snd_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:
+		dev_info(dev, "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) {
+			dev_info(dev,
+				   "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_parse_eld(struct device *dev, struct snd_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) {
+		dev_info(dev, "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) {
+		dev_info(dev, "HDMI: MNL is reserved value %d\n", mnl);
+		goto out_fail;
+	} else if (ELD_FIXED_BYTES + mnl > size) {
+		dev_info(dev, "HDMI: out of range MNL %d\n", mnl);
+		goto out_fail;
+	} else
+		strscpy(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) {
+			dev_info(dev, "HDMI: out of range SAD %d\n", i);
+			goto out_fail;
+		}
+		hdmi_update_short_audio_desc(dev, 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;
+}
+EXPORT_SYMBOL_GPL(snd_parse_eld);
+
+/*
+ * 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 */
+}
+
+static void eld_print_pcm_bits(int pcm, char *buf, int buflen)
+{
+	static const unsigned int bits[] = { 8, 16, 20, 24, 32 };
+	int i, j;
+
+	for (i = 0, j = 0; i < ARRAY_SIZE(bits); i++)
+		if (pcm & (ELD_PCM_BITS_8 << i))
+			j += scnprintf(buf + j, buflen - j,  " %d", bits[i]);
+
+	buf[j] = '\0'; /* necessary when j == 0 */
+}
+
+static void hdmi_show_short_audio_desc(struct device *dev,
+				       struct snd_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)
+		eld_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';
+
+	dev_dbg(dev,
+		"HDMI: supports coding type %s: channels = %d, rates =%s%s\n",
+		cea_audio_coding_type_names[a->format],
+		a->channels, buf, buf2);
+}
+
+static void snd_eld_print_channel_allocation(int spk_alloc, char *buf, int buflen)
+{
+	int i, j;
+
+	for (i = 0, j = 0; i < ARRAY_SIZE(cea_speaker_allocation_names); i++) {
+		if (spk_alloc & (1 << i))
+			j += scnprintf(buf + j, buflen - j,  " %s",
+					cea_speaker_allocation_names[i]);
+	}
+	buf[j] = '\0';	/* necessary when j == 0 */
+}
+
+void snd_show_eld(struct device *dev, struct snd_parsed_hdmi_eld *e)
+{
+	int i;
+
+	dev_dbg(dev, "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_eld_print_channel_allocation(e->spk_alloc, buf, sizeof(buf));
+		dev_dbg(dev, "HDMI: available speakers:%s\n", buf);
+	}
+
+	for (i = 0; i < e->sad_count; i++)
+		hdmi_show_short_audio_desc(dev, e->sad + i);
+}
+EXPORT_SYMBOL_GPL(snd_show_eld);
+
+#ifdef CONFIG_SND_PROC_FS
+static void hdmi_print_sad_info(int i, struct snd_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) {
+		eld_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_print_eld_info(struct snd_parsed_hdmi_eld *e,
+			struct snd_info_buffer *buffer)
+{
+	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_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_eld_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);
+}
+EXPORT_SYMBOL_GPL(snd_print_eld_info);
+#endif /* CONFIG_SND_PROC_FS */