projects / mirror_ubuntu-bionic-kernel.git / blame
| Commit | Line | Data |
|---|---|---|
| 838d1631 RK |
1 | /* |
| 2 | * PCM DRM helpers | |
| 3 | * | |
| 4 | * This program is free software; you can redistribute it and/or modify | |
| 5 | * it under the terms of the GNU General Public License version 2 as | |
| 6 | * published by the Free Software Foundation. | |
| 7 | */ | |
| 8 | #include <linux/export.h> | |
| 9 | #include <drm/drm_edid.h> | |
| 10 | #include <sound/pcm.h> | |
| 11 | #include <sound/pcm_drm_eld.h> | |
| 12 | ||
| 13 | static const unsigned int eld_rates[] = { | |
| 14 | 32000, | |
| 15 | 44100, | |
| 16 | 48000, | |
| 17 | 88200, | |
| 18 | 96000, | |
| 19 | 176400, | |
| 20 | 192000, | |
| 21 | }; | |
| 22 | ||
| 23 | static unsigned int sad_max_channels(const u8 *sad) | |
| 24 | { | |
| 25 | return 1 + (sad[0] & 7); | |
| 26 | } | |
| 27 | ||
| 28 | static int eld_limit_rates(struct snd_pcm_hw_params *params, | |
| 29 | struct snd_pcm_hw_rule *rule) | |
| 30 | { | |
| 31 | struct snd_interval *r = hw_param_interval(params, rule->var); | |
| b55f9fdc | 32 | const struct snd_interval *c; |
| 838d1631 RK |
33 | unsigned int rate_mask = 7, i; |
| 34 | const u8 *sad, *eld = rule->private; | |
| 35 | ||
| 36 | sad = drm_eld_sad(eld); | |
| 37 | if (sad) { | |
| b55f9fdc | 38 | c = hw_param_interval_c(params, SNDRV_PCM_HW_PARAM_CHANNELS); |
| 838d1631 RK |
39 | |
| 40 | for (i = drm_eld_sad_count(eld); i > 0; i--, sad += 3) { | |
| 41 | unsigned max_channels = sad_max_channels(sad); | |
| 42 | ||
| 43 | /* | |
| 44 | * Exclude SADs which do not include the | |
| 45 | * requested number of channels. | |
| 46 | */ | |
| 47 | if (c->min <= max_channels) | |
| 48 | rate_mask |= sad[1]; | |
| 49 | } | |
| 50 | } | |
| 51 | ||
| 52 | return snd_interval_list(r, ARRAY_SIZE(eld_rates), eld_rates, | |
| 53 | rate_mask); | |
| 54 | } | |
| 55 | ||
| 56 | static int eld_limit_channels(struct snd_pcm_hw_params *params, | |
| 57 | struct snd_pcm_hw_rule *rule) | |
| 58 | { | |
| 59 | struct snd_interval *c = hw_param_interval(params, rule->var); | |
| b55f9fdc | 60 | const struct snd_interval *r; |
| 838d1631 RK |
61 | struct snd_interval t = { .min = 1, .max = 2, .integer = 1, }; |
| 62 | unsigned int i; | |
| 63 | const u8 *sad, *eld = rule->private; | |
| 64 | ||
| 65 | sad = drm_eld_sad(eld); | |
| 66 | if (sad) { | |
| 67 | unsigned int rate_mask = 0; | |
| 68 | ||
| 69 | /* Convert the rate interval to a mask */ | |
| b55f9fdc | 70 | r = hw_param_interval_c(params, SNDRV_PCM_HW_PARAM_RATE); |
| 838d1631 RK |
71 | for (i = 0; i < ARRAY_SIZE(eld_rates); i++) |
| 72 | if (r->min <= eld_rates[i] && r->max >= eld_rates[i]) | |
| 73 | rate_mask |= BIT(i); | |
| 74 | ||
| 75 | for (i = drm_eld_sad_count(eld); i > 0; i--, sad += 3) | |
| 76 | if (rate_mask & sad[1]) | |
| 77 | t.max = max(t.max, sad_max_channels(sad)); | |
| 78 | } | |
| 79 | ||
| 80 | return snd_interval_refine(c, &t); | |
| 81 | } | |
| 82 | ||
| 83 | int snd_pcm_hw_constraint_eld(struct snd_pcm_runtime *runtime, void *eld) | |
| 84 | { | |
| 85 | int ret; | |
| 86 | ||
| 87 | ret = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_RATE, | |
| 88 | eld_limit_rates, eld, | |
| 89 | SNDRV_PCM_HW_PARAM_CHANNELS, -1); | |
| 90 | if (ret < 0) | |
| 91 | return ret; | |
| 92 | ||
| 93 | ret = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_CHANNELS, | |
| 94 | eld_limit_channels, eld, | |
| 95 | SNDRV_PCM_HW_PARAM_RATE, -1); | |
| 96 | ||
| 97 | return ret; | |
| 98 | } | |
| 99 | EXPORT_SYMBOL_GPL(snd_pcm_hw_constraint_eld); |