xref: /openbmc/linux/sound/pci/hda/hda_eld.c (revision dce54888)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Generic routines and proc interface for ELD(EDID Like Data) information
4  *
5  * Copyright(c) 2008 Intel Corporation.
6  * Copyright (c) 2013 Anssi Hannula <anssi.hannula@iki.fi>
7  *
8  * Authors:
9  * 		Wu Fengguang <wfg@linux.intel.com>
10  */
11 
12 #include <linux/init.h>
13 #include <linux/slab.h>
14 #include <sound/core.h>
15 #include <asm/unaligned.h>
16 #include <sound/hda_chmap.h>
17 #include <sound/hda_codec.h>
18 #include "hda_local.h"
19 
20 enum eld_versions {
21 	ELD_VER_CEA_861D	= 2,
22 	ELD_VER_PARTIAL		= 31,
23 };
24 
25 enum cea_edid_versions {
26 	CEA_EDID_VER_NONE	= 0,
27 	CEA_EDID_VER_CEA861	= 1,
28 	CEA_EDID_VER_CEA861A	= 2,
29 	CEA_EDID_VER_CEA861BCD	= 3,
30 	CEA_EDID_VER_RESERVED	= 4,
31 };
32 
33 static const char * const eld_connection_type_names[4] = {
34 	"HDMI",
35 	"DisplayPort",
36 	"2-reserved",
37 	"3-reserved"
38 };
39 
40 enum cea_audio_coding_types {
41 	AUDIO_CODING_TYPE_REF_STREAM_HEADER	=  0,
42 	AUDIO_CODING_TYPE_LPCM			=  1,
43 	AUDIO_CODING_TYPE_AC3			=  2,
44 	AUDIO_CODING_TYPE_MPEG1			=  3,
45 	AUDIO_CODING_TYPE_MP3			=  4,
46 	AUDIO_CODING_TYPE_MPEG2			=  5,
47 	AUDIO_CODING_TYPE_AACLC			=  6,
48 	AUDIO_CODING_TYPE_DTS			=  7,
49 	AUDIO_CODING_TYPE_ATRAC			=  8,
50 	AUDIO_CODING_TYPE_SACD			=  9,
51 	AUDIO_CODING_TYPE_EAC3			= 10,
52 	AUDIO_CODING_TYPE_DTS_HD		= 11,
53 	AUDIO_CODING_TYPE_MLP			= 12,
54 	AUDIO_CODING_TYPE_DST			= 13,
55 	AUDIO_CODING_TYPE_WMAPRO		= 14,
56 	AUDIO_CODING_TYPE_REF_CXT		= 15,
57 	/* also include valid xtypes below */
58 	AUDIO_CODING_TYPE_HE_AAC		= 15,
59 	AUDIO_CODING_TYPE_HE_AAC2		= 16,
60 	AUDIO_CODING_TYPE_MPEG_SURROUND		= 17,
61 };
62 
63 enum cea_audio_coding_xtypes {
64 	AUDIO_CODING_XTYPE_HE_REF_CT		= 0,
65 	AUDIO_CODING_XTYPE_HE_AAC		= 1,
66 	AUDIO_CODING_XTYPE_HE_AAC2		= 2,
67 	AUDIO_CODING_XTYPE_MPEG_SURROUND	= 3,
68 	AUDIO_CODING_XTYPE_FIRST_RESERVED	= 4,
69 };
70 
71 static const char * const cea_audio_coding_type_names[] = {
72 	/*  0 */ "undefined",
73 	/*  1 */ "LPCM",
74 	/*  2 */ "AC-3",
75 	/*  3 */ "MPEG1",
76 	/*  4 */ "MP3",
77 	/*  5 */ "MPEG2",
78 	/*  6 */ "AAC-LC",
79 	/*  7 */ "DTS",
80 	/*  8 */ "ATRAC",
81 	/*  9 */ "DSD (One Bit Audio)",
82 	/* 10 */ "E-AC-3/DD+ (Dolby Digital Plus)",
83 	/* 11 */ "DTS-HD",
84 	/* 12 */ "MLP (Dolby TrueHD)",
85 	/* 13 */ "DST",
86 	/* 14 */ "WMAPro",
87 	/* 15 */ "HE-AAC",
88 	/* 16 */ "HE-AACv2",
89 	/* 17 */ "MPEG Surround",
90 };
91 
92 /*
93  * The following two lists are shared between
94  * 	- HDMI audio InfoFrame (source to sink)
95  * 	- CEA E-EDID Extension (sink to source)
96  */
97 
98 /*
99  * SS1:SS0 index => sample size
100  */
101 static const int cea_sample_sizes[4] = {
102 	0,	 		/* 0: Refer to Stream Header */
103 	AC_SUPPCM_BITS_16,	/* 1: 16 bits */
104 	AC_SUPPCM_BITS_20,	/* 2: 20 bits */
105 	AC_SUPPCM_BITS_24,	/* 3: 24 bits */
106 };
107 
108 /*
109  * SF2:SF1:SF0 index => sampling frequency
110  */
111 static const int cea_sampling_frequencies[8] = {
112 	0,			/* 0: Refer to Stream Header */
113 	SNDRV_PCM_RATE_32000,	/* 1:  32000Hz */
114 	SNDRV_PCM_RATE_44100,	/* 2:  44100Hz */
115 	SNDRV_PCM_RATE_48000,	/* 3:  48000Hz */
116 	SNDRV_PCM_RATE_88200,	/* 4:  88200Hz */
117 	SNDRV_PCM_RATE_96000,	/* 5:  96000Hz */
118 	SNDRV_PCM_RATE_176400,	/* 6: 176400Hz */
119 	SNDRV_PCM_RATE_192000,	/* 7: 192000Hz */
120 };
121 
122 static unsigned int hdmi_get_eld_data(struct hda_codec *codec, hda_nid_t nid,
123 					int byte_index)
124 {
125 	unsigned int val;
126 
127 	val = snd_hda_codec_read(codec, nid, 0,
128 					AC_VERB_GET_HDMI_ELDD, byte_index);
129 #ifdef BE_PARANOID
130 	codec_info(codec, "HDMI: ELD data byte %d: 0x%x\n", byte_index, val);
131 #endif
132 	return val;
133 }
134 
135 #define GRAB_BITS(buf, byte, lowbit, bits) 		\
136 ({							\
137 	BUILD_BUG_ON(lowbit > 7);			\
138 	BUILD_BUG_ON(bits > 8);				\
139 	BUILD_BUG_ON(bits <= 0);			\
140 							\
141 	(buf[byte] >> (lowbit)) & ((1 << (bits)) - 1);	\
142 })
143 
144 static void hdmi_update_short_audio_desc(struct hda_codec *codec,
145 					 struct cea_sad *a,
146 					 const unsigned char *buf)
147 {
148 	int i;
149 	int val;
150 
151 	val = GRAB_BITS(buf, 1, 0, 7);
152 	a->rates = 0;
153 	for (i = 0; i < 7; i++)
154 		if (val & (1 << i))
155 			a->rates |= cea_sampling_frequencies[i + 1];
156 
157 	a->channels = GRAB_BITS(buf, 0, 0, 3);
158 	a->channels++;
159 
160 	a->sample_bits = 0;
161 	a->max_bitrate = 0;
162 
163 	a->format = GRAB_BITS(buf, 0, 3, 4);
164 	switch (a->format) {
165 	case AUDIO_CODING_TYPE_REF_STREAM_HEADER:
166 		codec_info(codec, "HDMI: audio coding type 0 not expected\n");
167 		break;
168 
169 	case AUDIO_CODING_TYPE_LPCM:
170 		val = GRAB_BITS(buf, 2, 0, 3);
171 		for (i = 0; i < 3; i++)
172 			if (val & (1 << i))
173 				a->sample_bits |= cea_sample_sizes[i + 1];
174 		break;
175 
176 	case AUDIO_CODING_TYPE_AC3:
177 	case AUDIO_CODING_TYPE_MPEG1:
178 	case AUDIO_CODING_TYPE_MP3:
179 	case AUDIO_CODING_TYPE_MPEG2:
180 	case AUDIO_CODING_TYPE_AACLC:
181 	case AUDIO_CODING_TYPE_DTS:
182 	case AUDIO_CODING_TYPE_ATRAC:
183 		a->max_bitrate = GRAB_BITS(buf, 2, 0, 8);
184 		a->max_bitrate *= 8000;
185 		break;
186 
187 	case AUDIO_CODING_TYPE_SACD:
188 		break;
189 
190 	case AUDIO_CODING_TYPE_EAC3:
191 		break;
192 
193 	case AUDIO_CODING_TYPE_DTS_HD:
194 		break;
195 
196 	case AUDIO_CODING_TYPE_MLP:
197 		break;
198 
199 	case AUDIO_CODING_TYPE_DST:
200 		break;
201 
202 	case AUDIO_CODING_TYPE_WMAPRO:
203 		a->profile = GRAB_BITS(buf, 2, 0, 3);
204 		break;
205 
206 	case AUDIO_CODING_TYPE_REF_CXT:
207 		a->format = GRAB_BITS(buf, 2, 3, 5);
208 		if (a->format == AUDIO_CODING_XTYPE_HE_REF_CT ||
209 		    a->format >= AUDIO_CODING_XTYPE_FIRST_RESERVED) {
210 			codec_info(codec,
211 				   "HDMI: audio coding xtype %d not expected\n",
212 				   a->format);
213 			a->format = 0;
214 		} else
215 			a->format += AUDIO_CODING_TYPE_HE_AAC -
216 				     AUDIO_CODING_XTYPE_HE_AAC;
217 		break;
218 	}
219 }
220 
221 /*
222  * Be careful, ELD buf could be totally rubbish!
223  */
224 int snd_hdmi_parse_eld(struct hda_codec *codec, struct parsed_hdmi_eld *e,
225 			  const unsigned char *buf, int size)
226 {
227 	int mnl;
228 	int i;
229 
230 	memset(e, 0, sizeof(*e));
231 	e->eld_ver = GRAB_BITS(buf, 0, 3, 5);
232 	if (e->eld_ver != ELD_VER_CEA_861D &&
233 	    e->eld_ver != ELD_VER_PARTIAL) {
234 		codec_info(codec, "HDMI: Unknown ELD version %d\n", e->eld_ver);
235 		goto out_fail;
236 	}
237 
238 	e->baseline_len = GRAB_BITS(buf, 2, 0, 8);
239 	mnl		= GRAB_BITS(buf, 4, 0, 5);
240 	e->cea_edid_ver	= GRAB_BITS(buf, 4, 5, 3);
241 
242 	e->support_hdcp	= GRAB_BITS(buf, 5, 0, 1);
243 	e->support_ai	= GRAB_BITS(buf, 5, 1, 1);
244 	e->conn_type	= GRAB_BITS(buf, 5, 2, 2);
245 	e->sad_count	= GRAB_BITS(buf, 5, 4, 4);
246 
247 	e->aud_synch_delay = GRAB_BITS(buf, 6, 0, 8) * 2;
248 	e->spk_alloc	= GRAB_BITS(buf, 7, 0, 7);
249 
250 	e->port_id	  = get_unaligned_le64(buf + 8);
251 
252 	/* not specified, but the spec's tendency is little endian */
253 	e->manufacture_id = get_unaligned_le16(buf + 16);
254 	e->product_id	  = get_unaligned_le16(buf + 18);
255 
256 	if (mnl > ELD_MAX_MNL) {
257 		codec_info(codec, "HDMI: MNL is reserved value %d\n", mnl);
258 		goto out_fail;
259 	} else if (ELD_FIXED_BYTES + mnl > size) {
260 		codec_info(codec, "HDMI: out of range MNL %d\n", mnl);
261 		goto out_fail;
262 	} else
263 		strscpy(e->monitor_name, buf + ELD_FIXED_BYTES, mnl + 1);
264 
265 	for (i = 0; i < e->sad_count; i++) {
266 		if (ELD_FIXED_BYTES + mnl + 3 * (i + 1) > size) {
267 			codec_info(codec, "HDMI: out of range SAD %d\n", i);
268 			goto out_fail;
269 		}
270 		hdmi_update_short_audio_desc(codec, e->sad + i,
271 					buf + ELD_FIXED_BYTES + mnl + 3 * i);
272 	}
273 
274 	/*
275 	 * HDMI sink's ELD info cannot always be retrieved for now, e.g.
276 	 * in console or for audio devices. Assume the highest speakers
277 	 * configuration, to _not_ prohibit multi-channel audio playback.
278 	 */
279 	if (!e->spk_alloc)
280 		e->spk_alloc = 0xffff;
281 
282 	return 0;
283 
284 out_fail:
285 	return -EINVAL;
286 }
287 
288 int snd_hdmi_get_eld_size(struct hda_codec *codec, hda_nid_t nid)
289 {
290 	return snd_hda_codec_read(codec, nid, 0, AC_VERB_GET_HDMI_DIP_SIZE,
291 						 AC_DIPSIZE_ELD_BUF);
292 }
293 
294 int snd_hdmi_get_eld(struct hda_codec *codec, hda_nid_t nid,
295 		     unsigned char *buf, int *eld_size)
296 {
297 	int i;
298 	int ret = 0;
299 	int size;
300 
301 	/*
302 	 * ELD size is initialized to zero in caller function. If no errors and
303 	 * ELD is valid, actual eld_size is assigned.
304 	 */
305 
306 	size = snd_hdmi_get_eld_size(codec, nid);
307 	if (size == 0) {
308 		/* wfg: workaround for ASUS P5E-VM HDMI board */
309 		codec_info(codec, "HDMI: ELD buf size is 0, force 128\n");
310 		size = 128;
311 	}
312 	if (size < ELD_FIXED_BYTES || size > ELD_MAX_SIZE) {
313 		codec_info(codec, "HDMI: invalid ELD buf size %d\n", size);
314 		return -ERANGE;
315 	}
316 
317 	/* set ELD buffer */
318 	for (i = 0; i < size; i++) {
319 		unsigned int val = hdmi_get_eld_data(codec, nid, i);
320 		/*
321 		 * Graphics driver might be writing to ELD buffer right now.
322 		 * Just abort. The caller will repoll after a while.
323 		 */
324 		if (!(val & AC_ELDD_ELD_VALID)) {
325 			codec_info(codec, "HDMI: invalid ELD data byte %d\n", i);
326 			ret = -EINVAL;
327 			goto error;
328 		}
329 		val &= AC_ELDD_ELD_DATA;
330 		/*
331 		 * The first byte cannot be zero. This can happen on some DVI
332 		 * connections. Some Intel chips may also need some 250ms delay
333 		 * to return non-zero ELD data, even when the graphics driver
334 		 * correctly writes ELD content before setting ELD_valid bit.
335 		 */
336 		if (!val && !i) {
337 			codec_dbg(codec, "HDMI: 0 ELD data\n");
338 			ret = -EINVAL;
339 			goto error;
340 		}
341 		buf[i] = val;
342 	}
343 
344 	*eld_size = size;
345 error:
346 	return ret;
347 }
348 
349 /*
350  * SNDRV_PCM_RATE_* and AC_PAR_PCM values don't match, print correct rates with
351  * hdmi-specific routine.
352  */
353 static void hdmi_print_pcm_rates(int pcm, char *buf, int buflen)
354 {
355 	static const unsigned int alsa_rates[] = {
356 		5512, 8000, 11025, 16000, 22050, 32000, 44100, 48000, 64000,
357 		88200, 96000, 176400, 192000, 384000
358 	};
359 	int i, j;
360 
361 	for (i = 0, j = 0; i < ARRAY_SIZE(alsa_rates); i++)
362 		if (pcm & (1 << i))
363 			j += scnprintf(buf + j, buflen - j,  " %d",
364 				alsa_rates[i]);
365 
366 	buf[j] = '\0'; /* necessary when j == 0 */
367 }
368 
369 #define SND_PRINT_RATES_ADVISED_BUFSIZE	80
370 
371 static void hdmi_show_short_audio_desc(struct hda_codec *codec,
372 				       struct cea_sad *a)
373 {
374 	char buf[SND_PRINT_RATES_ADVISED_BUFSIZE];
375 	char buf2[8 + SND_PRINT_BITS_ADVISED_BUFSIZE] = ", bits =";
376 
377 	if (!a->format)
378 		return;
379 
380 	hdmi_print_pcm_rates(a->rates, buf, sizeof(buf));
381 
382 	if (a->format == AUDIO_CODING_TYPE_LPCM)
383 		snd_print_pcm_bits(a->sample_bits, buf2 + 8, sizeof(buf2) - 8);
384 	else if (a->max_bitrate)
385 		snprintf(buf2, sizeof(buf2),
386 				", max bitrate = %d", a->max_bitrate);
387 	else
388 		buf2[0] = '\0';
389 
390 	codec_dbg(codec,
391 		  "HDMI: supports coding type %s: channels = %d, rates =%s%s\n",
392 		  cea_audio_coding_type_names[a->format],
393 		  a->channels, buf, buf2);
394 }
395 
396 void snd_hdmi_show_eld(struct hda_codec *codec, struct parsed_hdmi_eld *e)
397 {
398 	int i;
399 
400 	codec_dbg(codec, "HDMI: detected monitor %s at connection type %s\n",
401 			e->monitor_name,
402 			eld_connection_type_names[e->conn_type]);
403 
404 	if (e->spk_alloc) {
405 		char buf[SND_PRINT_CHANNEL_ALLOCATION_ADVISED_BUFSIZE];
406 		snd_hdac_print_channel_allocation(e->spk_alloc, buf, sizeof(buf));
407 		codec_dbg(codec, "HDMI: available speakers:%s\n", buf);
408 	}
409 
410 	for (i = 0; i < e->sad_count; i++)
411 		hdmi_show_short_audio_desc(codec, e->sad + i);
412 }
413 
414 #ifdef CONFIG_SND_PROC_FS
415 
416 static void hdmi_print_sad_info(int i, struct cea_sad *a,
417 				struct snd_info_buffer *buffer)
418 {
419 	char buf[SND_PRINT_RATES_ADVISED_BUFSIZE];
420 
421 	snd_iprintf(buffer, "sad%d_coding_type\t[0x%x] %s\n",
422 			i, a->format, cea_audio_coding_type_names[a->format]);
423 	snd_iprintf(buffer, "sad%d_channels\t\t%d\n", i, a->channels);
424 
425 	hdmi_print_pcm_rates(a->rates, buf, sizeof(buf));
426 	snd_iprintf(buffer, "sad%d_rates\t\t[0x%x]%s\n", i, a->rates, buf);
427 
428 	if (a->format == AUDIO_CODING_TYPE_LPCM) {
429 		snd_print_pcm_bits(a->sample_bits, buf, sizeof(buf));
430 		snd_iprintf(buffer, "sad%d_bits\t\t[0x%x]%s\n",
431 							i, a->sample_bits, buf);
432 	}
433 
434 	if (a->max_bitrate)
435 		snd_iprintf(buffer, "sad%d_max_bitrate\t%d\n",
436 							i, a->max_bitrate);
437 
438 	if (a->profile)
439 		snd_iprintf(buffer, "sad%d_profile\t\t%d\n", i, a->profile);
440 }
441 
442 void snd_hdmi_print_eld_info(struct hdmi_eld *eld,
443 			     struct snd_info_buffer *buffer,
444 			     hda_nid_t pin_nid, int dev_id, hda_nid_t cvt_nid)
445 {
446 	struct parsed_hdmi_eld *e = &eld->info;
447 	char buf[SND_PRINT_CHANNEL_ALLOCATION_ADVISED_BUFSIZE];
448 	int i;
449 	static const char * const eld_version_names[32] = {
450 		"reserved",
451 		"reserved",
452 		"CEA-861D or below",
453 		[3 ... 30] = "reserved",
454 		[31] = "partial"
455 	};
456 	static const char * const cea_edid_version_names[8] = {
457 		"no CEA EDID Timing Extension block present",
458 		"CEA-861",
459 		"CEA-861-A",
460 		"CEA-861-B, C or D",
461 		[4 ... 7] = "reserved"
462 	};
463 
464 	snd_iprintf(buffer, "monitor_present\t\t%d\n", eld->monitor_present);
465 	snd_iprintf(buffer, "eld_valid\t\t%d\n", eld->eld_valid);
466 	snd_iprintf(buffer, "codec_pin_nid\t\t0x%x\n", pin_nid);
467 	snd_iprintf(buffer, "codec_dev_id\t\t0x%x\n", dev_id);
468 	snd_iprintf(buffer, "codec_cvt_nid\t\t0x%x\n", cvt_nid);
469 	if (!eld->eld_valid)
470 		return;
471 	snd_iprintf(buffer, "monitor_name\t\t%s\n", e->monitor_name);
472 	snd_iprintf(buffer, "connection_type\t\t%s\n",
473 				eld_connection_type_names[e->conn_type]);
474 	snd_iprintf(buffer, "eld_version\t\t[0x%x] %s\n", e->eld_ver,
475 					eld_version_names[e->eld_ver]);
476 	snd_iprintf(buffer, "edid_version\t\t[0x%x] %s\n", e->cea_edid_ver,
477 				cea_edid_version_names[e->cea_edid_ver]);
478 	snd_iprintf(buffer, "manufacture_id\t\t0x%x\n", e->manufacture_id);
479 	snd_iprintf(buffer, "product_id\t\t0x%x\n", e->product_id);
480 	snd_iprintf(buffer, "port_id\t\t\t0x%llx\n", (long long)e->port_id);
481 	snd_iprintf(buffer, "support_hdcp\t\t%d\n", e->support_hdcp);
482 	snd_iprintf(buffer, "support_ai\t\t%d\n", e->support_ai);
483 	snd_iprintf(buffer, "audio_sync_delay\t%d\n", e->aud_synch_delay);
484 
485 	snd_hdac_print_channel_allocation(e->spk_alloc, buf, sizeof(buf));
486 	snd_iprintf(buffer, "speakers\t\t[0x%x]%s\n", e->spk_alloc, buf);
487 
488 	snd_iprintf(buffer, "sad_count\t\t%d\n", e->sad_count);
489 
490 	for (i = 0; i < e->sad_count; i++)
491 		hdmi_print_sad_info(i, e->sad + i, buffer);
492 }
493 
494 void snd_hdmi_write_eld_info(struct hdmi_eld *eld,
495 			     struct snd_info_buffer *buffer)
496 {
497 	struct parsed_hdmi_eld *e = &eld->info;
498 	char line[64];
499 	char name[64];
500 	char *sname;
501 	long long val;
502 	unsigned int n;
503 
504 	while (!snd_info_get_line(buffer, line, sizeof(line))) {
505 		if (sscanf(line, "%s %llx", name, &val) != 2)
506 			continue;
507 		/*
508 		 * We don't allow modification to these fields:
509 		 * 	monitor_name manufacture_id product_id
510 		 * 	eld_version edid_version
511 		 */
512 		if (!strcmp(name, "monitor_present"))
513 			eld->monitor_present = val;
514 		else if (!strcmp(name, "eld_valid"))
515 			eld->eld_valid = val;
516 		else if (!strcmp(name, "connection_type"))
517 			e->conn_type = val;
518 		else if (!strcmp(name, "port_id"))
519 			e->port_id = val;
520 		else if (!strcmp(name, "support_hdcp"))
521 			e->support_hdcp = val;
522 		else if (!strcmp(name, "support_ai"))
523 			e->support_ai = val;
524 		else if (!strcmp(name, "audio_sync_delay"))
525 			e->aud_synch_delay = val;
526 		else if (!strcmp(name, "speakers"))
527 			e->spk_alloc = val;
528 		else if (!strcmp(name, "sad_count"))
529 			e->sad_count = val;
530 		else if (!strncmp(name, "sad", 3)) {
531 			sname = name + 4;
532 			n = name[3] - '0';
533 			if (name[4] >= '0' && name[4] <= '9') {
534 				sname++;
535 				n = 10 * n + name[4] - '0';
536 			}
537 			if (n >= ELD_MAX_SAD)
538 				continue;
539 			if (!strcmp(sname, "_coding_type"))
540 				e->sad[n].format = val;
541 			else if (!strcmp(sname, "_channels"))
542 				e->sad[n].channels = val;
543 			else if (!strcmp(sname, "_rates"))
544 				e->sad[n].rates = val;
545 			else if (!strcmp(sname, "_bits"))
546 				e->sad[n].sample_bits = val;
547 			else if (!strcmp(sname, "_max_bitrate"))
548 				e->sad[n].max_bitrate = val;
549 			else if (!strcmp(sname, "_profile"))
550 				e->sad[n].profile = val;
551 			if (n >= e->sad_count)
552 				e->sad_count = n + 1;
553 		}
554 	}
555 }
556 #endif /* CONFIG_SND_PROC_FS */
557 
558 /* update PCM info based on ELD */
559 void snd_hdmi_eld_update_pcm_info(struct parsed_hdmi_eld *e,
560 			      struct hda_pcm_stream *hinfo)
561 {
562 	u32 rates;
563 	u64 formats;
564 	unsigned int maxbps;
565 	unsigned int channels_max;
566 	int i;
567 
568 	/* assume basic audio support (the basic audio flag is not in ELD;
569 	 * however, all audio capable sinks are required to support basic
570 	 * audio) */
571 	rates = SNDRV_PCM_RATE_32000 | SNDRV_PCM_RATE_44100 |
572 		SNDRV_PCM_RATE_48000;
573 	formats = SNDRV_PCM_FMTBIT_S16_LE;
574 	maxbps = 16;
575 	channels_max = 2;
576 	for (i = 0; i < e->sad_count; i++) {
577 		struct cea_sad *a = &e->sad[i];
578 		rates |= a->rates;
579 		if (a->channels > channels_max)
580 			channels_max = a->channels;
581 		if (a->format == AUDIO_CODING_TYPE_LPCM) {
582 			if (a->sample_bits & AC_SUPPCM_BITS_20) {
583 				formats |= SNDRV_PCM_FMTBIT_S32_LE;
584 				if (maxbps < 20)
585 					maxbps = 20;
586 			}
587 			if (a->sample_bits & AC_SUPPCM_BITS_24) {
588 				formats |= SNDRV_PCM_FMTBIT_S32_LE;
589 				if (maxbps < 24)
590 					maxbps = 24;
591 			}
592 		}
593 	}
594 
595 	/* restrict the parameters by the values the codec provides */
596 	hinfo->rates &= rates;
597 	hinfo->formats &= formats;
598 	hinfo->maxbps = min(hinfo->maxbps, maxbps);
599 	hinfo->channels_max = min(hinfo->channels_max, channels_max);
600 }
601 
602 
603 /* ATI/AMD specific stuff (ELD emulation) */
604 
605 #define ATI_VERB_SET_AUDIO_DESCRIPTOR	0x776
606 #define ATI_VERB_SET_SINK_INFO_INDEX	0x780
607 #define ATI_VERB_GET_SPEAKER_ALLOCATION	0xf70
608 #define ATI_VERB_GET_AUDIO_DESCRIPTOR	0xf76
609 #define ATI_VERB_GET_AUDIO_VIDEO_DELAY	0xf7b
610 #define ATI_VERB_GET_SINK_INFO_INDEX	0xf80
611 #define ATI_VERB_GET_SINK_INFO_DATA	0xf81
612 
613 #define ATI_SPKALLOC_SPKALLOC		0x007f
614 #define ATI_SPKALLOC_TYPE_HDMI		0x0100
615 #define ATI_SPKALLOC_TYPE_DISPLAYPORT	0x0200
616 
617 /* first three bytes are just standard SAD */
618 #define ATI_AUDIODESC_CHANNELS		0x00000007
619 #define ATI_AUDIODESC_RATES		0x0000ff00
620 #define ATI_AUDIODESC_LPCM_STEREO_RATES	0xff000000
621 
622 /* in standard HDMI VSDB format */
623 #define ATI_DELAY_VIDEO_LATENCY		0x000000ff
624 #define ATI_DELAY_AUDIO_LATENCY		0x0000ff00
625 
626 enum ati_sink_info_idx {
627 	ATI_INFO_IDX_MANUFACTURER_ID	= 0,
628 	ATI_INFO_IDX_PRODUCT_ID		= 1,
629 	ATI_INFO_IDX_SINK_DESC_LEN	= 2,
630 	ATI_INFO_IDX_PORT_ID_LOW	= 3,
631 	ATI_INFO_IDX_PORT_ID_HIGH	= 4,
632 	ATI_INFO_IDX_SINK_DESC_FIRST	= 5,
633 	ATI_INFO_IDX_SINK_DESC_LAST	= 22, /* max len 18 bytes */
634 };
635 
636 int snd_hdmi_get_eld_ati(struct hda_codec *codec, hda_nid_t nid,
637 			 unsigned char *buf, int *eld_size, bool rev3_or_later)
638 {
639 	int spkalloc, ati_sad, aud_synch;
640 	int sink_desc_len = 0;
641 	int pos, i;
642 
643 	/* ATI/AMD does not have ELD, emulate it */
644 
645 	spkalloc = snd_hda_codec_read(codec, nid, 0, ATI_VERB_GET_SPEAKER_ALLOCATION, 0);
646 
647 	if (spkalloc <= 0) {
648 		codec_info(codec, "HDMI ATI/AMD: no speaker allocation for ELD\n");
649 		return -EINVAL;
650 	}
651 
652 	memset(buf, 0, ELD_FIXED_BYTES + ELD_MAX_MNL + ELD_MAX_SAD * 3);
653 
654 	/* version */
655 	buf[0] = ELD_VER_CEA_861D << 3;
656 
657 	/* speaker allocation from EDID */
658 	buf[7] = spkalloc & ATI_SPKALLOC_SPKALLOC;
659 
660 	/* is DisplayPort? */
661 	if (spkalloc & ATI_SPKALLOC_TYPE_DISPLAYPORT)
662 		buf[5] |= 0x04;
663 
664 	pos = ELD_FIXED_BYTES;
665 
666 	if (rev3_or_later) {
667 		int sink_info;
668 
669 		snd_hda_codec_write(codec, nid, 0, ATI_VERB_SET_SINK_INFO_INDEX, ATI_INFO_IDX_PORT_ID_LOW);
670 		sink_info = snd_hda_codec_read(codec, nid, 0, ATI_VERB_GET_SINK_INFO_DATA, 0);
671 		put_unaligned_le32(sink_info, buf + 8);
672 
673 		snd_hda_codec_write(codec, nid, 0, ATI_VERB_SET_SINK_INFO_INDEX, ATI_INFO_IDX_PORT_ID_HIGH);
674 		sink_info = snd_hda_codec_read(codec, nid, 0, ATI_VERB_GET_SINK_INFO_DATA, 0);
675 		put_unaligned_le32(sink_info, buf + 12);
676 
677 		snd_hda_codec_write(codec, nid, 0, ATI_VERB_SET_SINK_INFO_INDEX, ATI_INFO_IDX_MANUFACTURER_ID);
678 		sink_info = snd_hda_codec_read(codec, nid, 0, ATI_VERB_GET_SINK_INFO_DATA, 0);
679 		put_unaligned_le16(sink_info, buf + 16);
680 
681 		snd_hda_codec_write(codec, nid, 0, ATI_VERB_SET_SINK_INFO_INDEX, ATI_INFO_IDX_PRODUCT_ID);
682 		sink_info = snd_hda_codec_read(codec, nid, 0, ATI_VERB_GET_SINK_INFO_DATA, 0);
683 		put_unaligned_le16(sink_info, buf + 18);
684 
685 		snd_hda_codec_write(codec, nid, 0, ATI_VERB_SET_SINK_INFO_INDEX, ATI_INFO_IDX_SINK_DESC_LEN);
686 		sink_desc_len = snd_hda_codec_read(codec, nid, 0, ATI_VERB_GET_SINK_INFO_DATA, 0);
687 
688 		if (sink_desc_len > ELD_MAX_MNL) {
689 			codec_info(codec, "HDMI ATI/AMD: Truncating HDMI sink description with length %d\n",
690 				   sink_desc_len);
691 			sink_desc_len = ELD_MAX_MNL;
692 		}
693 
694 		buf[4] |= sink_desc_len;
695 
696 		for (i = 0; i < sink_desc_len; i++) {
697 			snd_hda_codec_write(codec, nid, 0, ATI_VERB_SET_SINK_INFO_INDEX, ATI_INFO_IDX_SINK_DESC_FIRST + i);
698 			buf[pos++] = snd_hda_codec_read(codec, nid, 0, ATI_VERB_GET_SINK_INFO_DATA, 0);
699 		}
700 	}
701 
702 	for (i = AUDIO_CODING_TYPE_LPCM; i <= AUDIO_CODING_TYPE_WMAPRO; i++) {
703 		if (i == AUDIO_CODING_TYPE_SACD || i == AUDIO_CODING_TYPE_DST)
704 			continue; /* not handled by ATI/AMD */
705 
706 		snd_hda_codec_write(codec, nid, 0, ATI_VERB_SET_AUDIO_DESCRIPTOR, i << 3);
707 		ati_sad = snd_hda_codec_read(codec, nid, 0, ATI_VERB_GET_AUDIO_DESCRIPTOR, 0);
708 
709 		if (ati_sad <= 0)
710 			continue;
711 
712 		if (ati_sad & ATI_AUDIODESC_RATES) {
713 			/* format is supported, copy SAD as-is */
714 			buf[pos++] = (ati_sad & 0x0000ff) >> 0;
715 			buf[pos++] = (ati_sad & 0x00ff00) >> 8;
716 			buf[pos++] = (ati_sad & 0xff0000) >> 16;
717 		}
718 
719 		if (i == AUDIO_CODING_TYPE_LPCM
720 		    && (ati_sad & ATI_AUDIODESC_LPCM_STEREO_RATES)
721 		    && (ati_sad & ATI_AUDIODESC_LPCM_STEREO_RATES) >> 16 != (ati_sad & ATI_AUDIODESC_RATES)) {
722 			/* for PCM there is a separate stereo rate mask */
723 			buf[pos++] = ((ati_sad & 0x000000ff) & ~ATI_AUDIODESC_CHANNELS) | 0x1;
724 			/* rates from the extra byte */
725 			buf[pos++] = (ati_sad & 0xff000000) >> 24;
726 			buf[pos++] = (ati_sad & 0x00ff0000) >> 16;
727 		}
728 	}
729 
730 	if (pos == ELD_FIXED_BYTES + sink_desc_len) {
731 		codec_info(codec, "HDMI ATI/AMD: no audio descriptors for ELD\n");
732 		return -EINVAL;
733 	}
734 
735 	/*
736 	 * HDMI VSDB latency format:
737 	 * separately for both audio and video:
738 	 *  0          field not valid or unknown latency
739 	 *  [1..251]   msecs = (x-1)*2  (max 500ms with x = 251 = 0xfb)
740 	 *  255        audio/video not supported
741 	 *
742 	 * HDA latency format:
743 	 * single value indicating video latency relative to audio:
744 	 *  0          unknown or 0ms
745 	 *  [1..250]   msecs = x*2  (max 500ms with x = 250 = 0xfa)
746 	 *  [251..255] reserved
747 	 */
748 	aud_synch = snd_hda_codec_read(codec, nid, 0, ATI_VERB_GET_AUDIO_VIDEO_DELAY, 0);
749 	if ((aud_synch & ATI_DELAY_VIDEO_LATENCY) && (aud_synch & ATI_DELAY_AUDIO_LATENCY)) {
750 		int video_latency_hdmi = (aud_synch & ATI_DELAY_VIDEO_LATENCY);
751 		int audio_latency_hdmi = (aud_synch & ATI_DELAY_AUDIO_LATENCY) >> 8;
752 
753 		if (video_latency_hdmi <= 0xfb && audio_latency_hdmi <= 0xfb &&
754 		    video_latency_hdmi > audio_latency_hdmi)
755 			buf[6] = video_latency_hdmi - audio_latency_hdmi;
756 		/* else unknown/invalid or 0ms or video ahead of audio, so use zero */
757 	}
758 
759 	/* SAD count */
760 	buf[5] |= ((pos - ELD_FIXED_BYTES - sink_desc_len) / 3) << 4;
761 
762 	/* Baseline ELD block length is 4-byte aligned */
763 	pos = round_up(pos, 4);
764 
765 	/* Baseline ELD length (4-byte header is not counted in) */
766 	buf[2] = (pos - 4) / 4;
767 
768 	*eld_size = pos;
769 
770 	return 0;
771 }
772