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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * PCM DRM helpers4 */5#include <linux/bitfield.h>6#include <linux/export.h>7#include <linux/hdmi.h>8#include <drm/drm_edid.h>9#include <drm/drm_eld.h>10#include <sound/pcm.h>11#include <sound/pcm_drm_eld.h>12 13#define SAD0_CHANNELS_MASK GENMASK(2, 0) /* max number of channels - 1 */14#define SAD0_FORMAT_MASK GENMASK(6, 3) /* audio format */15 16#define SAD1_RATE_MASK GENMASK(6, 0) /* bitfield of supported rates */17#define SAD1_RATE_32000_MASK BIT(0)18#define SAD1_RATE_44100_MASK BIT(1)19#define SAD1_RATE_48000_MASK BIT(2)20#define SAD1_RATE_88200_MASK BIT(3)21#define SAD1_RATE_96000_MASK BIT(4)22#define SAD1_RATE_176400_MASK BIT(5)23#define SAD1_RATE_192000_MASK BIT(6)24 25static const unsigned int eld_rates[] = {26 32000,27 44100,28 48000,29 88200,30 96000,31 176400,32 192000,33};34 35static unsigned int map_rate_families(const u8 *sad,36 unsigned int mask_32000,37 unsigned int mask_44100,38 unsigned int mask_48000)39{40 unsigned int rate_mask = 0;41 42 if (sad[1] & SAD1_RATE_32000_MASK)43 rate_mask |= mask_32000;44 if (sad[1] & (SAD1_RATE_44100_MASK | SAD1_RATE_88200_MASK | SAD1_RATE_176400_MASK))45 rate_mask |= mask_44100;46 if (sad[1] & (SAD1_RATE_48000_MASK | SAD1_RATE_96000_MASK | SAD1_RATE_192000_MASK))47 rate_mask |= mask_48000;48 return rate_mask;49}50 51static unsigned int sad_rate_mask(const u8 *sad)52{53 switch (FIELD_GET(SAD0_FORMAT_MASK, sad[0])) {54 case HDMI_AUDIO_CODING_TYPE_PCM:55 return sad[1] & SAD1_RATE_MASK;56 case HDMI_AUDIO_CODING_TYPE_AC3:57 case HDMI_AUDIO_CODING_TYPE_DTS:58 return map_rate_families(sad,59 SAD1_RATE_32000_MASK,60 SAD1_RATE_44100_MASK,61 SAD1_RATE_48000_MASK);62 case HDMI_AUDIO_CODING_TYPE_EAC3:63 case HDMI_AUDIO_CODING_TYPE_DTS_HD:64 case HDMI_AUDIO_CODING_TYPE_MLP:65 return map_rate_families(sad,66 0,67 SAD1_RATE_176400_MASK,68 SAD1_RATE_192000_MASK);69 default:70 /* TODO adjust for other compressed formats as well */71 return sad[1] & SAD1_RATE_MASK;72 }73}74 75static unsigned int sad_max_channels(const u8 *sad)76{77 switch (FIELD_GET(SAD0_FORMAT_MASK, sad[0])) {78 case HDMI_AUDIO_CODING_TYPE_PCM:79 return 1 + FIELD_GET(SAD0_CHANNELS_MASK, sad[0]);80 case HDMI_AUDIO_CODING_TYPE_AC3:81 case HDMI_AUDIO_CODING_TYPE_DTS:82 case HDMI_AUDIO_CODING_TYPE_EAC3:83 return 2;84 case HDMI_AUDIO_CODING_TYPE_DTS_HD:85 case HDMI_AUDIO_CODING_TYPE_MLP:86 return 8;87 default:88 /* TODO adjust for other compressed formats as well */89 return 1 + FIELD_GET(SAD0_CHANNELS_MASK, sad[0]);90 }91}92 93static int eld_limit_rates(struct snd_pcm_hw_params *params,94 struct snd_pcm_hw_rule *rule)95{96 struct snd_interval *r = hw_param_interval(params, rule->var);97 const struct snd_interval *c;98 unsigned int rate_mask = 7, i;99 const u8 *sad, *eld = rule->private;100 101 sad = drm_eld_sad(eld);102 if (sad) {103 c = hw_param_interval_c(params, SNDRV_PCM_HW_PARAM_CHANNELS);104 105 for (i = drm_eld_sad_count(eld); i > 0; i--, sad += 3) {106 unsigned max_channels = sad_max_channels(sad);107 108 /*109 * Exclude SADs which do not include the110 * requested number of channels.111 */112 if (c->min <= max_channels)113 rate_mask |= sad_rate_mask(sad);114 }115 }116 117 return snd_interval_list(r, ARRAY_SIZE(eld_rates), eld_rates,118 rate_mask);119}120 121static int eld_limit_channels(struct snd_pcm_hw_params *params,122 struct snd_pcm_hw_rule *rule)123{124 struct snd_interval *c = hw_param_interval(params, rule->var);125 const struct snd_interval *r;126 struct snd_interval t = { .min = 1, .max = 2, .integer = 1, };127 unsigned int i;128 const u8 *sad, *eld = rule->private;129 130 sad = drm_eld_sad(eld);131 if (sad) {132 unsigned int rate_mask = 0;133 134 /* Convert the rate interval to a mask */135 r = hw_param_interval_c(params, SNDRV_PCM_HW_PARAM_RATE);136 for (i = 0; i < ARRAY_SIZE(eld_rates); i++)137 if (r->min <= eld_rates[i] && r->max >= eld_rates[i])138 rate_mask |= BIT(i);139 140 for (i = drm_eld_sad_count(eld); i > 0; i--, sad += 3)141 if (rate_mask & sad_rate_mask(sad))142 t.max = max(t.max, sad_max_channels(sad));143 }144 145 return snd_interval_refine(c, &t);146}147 148int snd_pcm_hw_constraint_eld(struct snd_pcm_runtime *runtime, void *eld)149{150 int ret;151 152 ret = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_RATE,153 eld_limit_rates, eld,154 SNDRV_PCM_HW_PARAM_CHANNELS, -1);155 if (ret < 0)156 return ret;157 158 ret = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_CHANNELS,159 eld_limit_channels, eld,160 SNDRV_PCM_HW_PARAM_RATE, -1);161 162 return ret;163}164EXPORT_SYMBOL_GPL(snd_pcm_hw_constraint_eld);165