projects / linux-2.6-block.git / blame
| Commit | Line | Data |
|---|---|---|
| d2912cb1 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
| 838d1631 RK |
2 | /* |
| 3 | * PCM DRM helpers | |
| 838d1631 RK |
4 | */ |
| 5 | #include <linux/export.h> | |
| 6 | #include <drm/drm_edid.h> | |
| 7 | #include <sound/pcm.h> | |
| 8 | #include <sound/pcm_drm_eld.h> | |
| 9 | ||
| 10 | static const unsigned int eld_rates[] = { | |
| 11 | 32000, | |
| 12 | 44100, | |
| 13 | 48000, | |
| 14 | 88200, | |
| 15 | 96000, | |
| 16 | 176400, | |
| 17 | 192000, | |
| 18 | }; | |
| 19 | ||
| 20 | static unsigned int sad_max_channels(const u8 *sad) | |
| 21 | { | |
| 22 | return 1 + (sad[0] & 7); | |
| 23 | } | |
| 24 | ||
| 25 | static int eld_limit_rates(struct snd_pcm_hw_params *params, | |
| 26 | struct snd_pcm_hw_rule *rule) | |
| 27 | { | |
| 28 | struct snd_interval *r = hw_param_interval(params, rule->var); | |
| b55f9fdc | 29 | const struct snd_interval *c; |
| 838d1631 RK |
30 | unsigned int rate_mask = 7, i; |
| 31 | const u8 *sad, *eld = rule->private; | |
| 32 | ||
| 33 | sad = drm_eld_sad(eld); | |
| 34 | if (sad) { | |
| b55f9fdc | 35 | c = hw_param_interval_c(params, SNDRV_PCM_HW_PARAM_CHANNELS); |
| 838d1631 RK |
36 | |
| 37 | for (i = drm_eld_sad_count(eld); i > 0; i--, sad += 3) { | |
| 38 | unsigned max_channels = sad_max_channels(sad); | |
| 39 | ||
| 40 | /* | |
| 41 | * Exclude SADs which do not include the | |
| 42 | * requested number of channels. | |
| 43 | */ | |
| 44 | if (c->min <= max_channels) | |
| 45 | rate_mask |= sad[1]; | |
| 46 | } | |
| 47 | } | |
| 48 | ||
| 49 | return snd_interval_list(r, ARRAY_SIZE(eld_rates), eld_rates, | |
| 50 | rate_mask); | |
| 51 | } | |
| 52 | ||
| 53 | static int eld_limit_channels(struct snd_pcm_hw_params *params, | |
| 54 | struct snd_pcm_hw_rule *rule) | |
| 55 | { | |
| 56 | struct snd_interval *c = hw_param_interval(params, rule->var); | |
| b55f9fdc | 57 | const struct snd_interval *r; |
| 838d1631 RK |
58 | struct snd_interval t = { .min = 1, .max = 2, .integer = 1, }; |
| 59 | unsigned int i; | |
| 60 | const u8 *sad, *eld = rule->private; | |
| 61 | ||
| 62 | sad = drm_eld_sad(eld); | |
| 63 | if (sad) { | |
| 64 | unsigned int rate_mask = 0; | |
| 65 | ||
| 66 | /* Convert the rate interval to a mask */ | |
| b55f9fdc | 67 | r = hw_param_interval_c(params, SNDRV_PCM_HW_PARAM_RATE); |
| 838d1631 RK |
68 | for (i = 0; i < ARRAY_SIZE(eld_rates); i++) |
| 69 | if (r->min <= eld_rates[i] && r->max >= eld_rates[i]) | |
| 70 | rate_mask |= BIT(i); | |
| 71 | ||
| 72 | for (i = drm_eld_sad_count(eld); i > 0; i--, sad += 3) | |
| 73 | if (rate_mask & sad[1]) | |
| 74 | t.max = max(t.max, sad_max_channels(sad)); | |
| 75 | } | |
| 76 | ||
| 77 | return snd_interval_refine(c, &t); | |
| 78 | } | |
| 79 | ||
| 80 | int snd_pcm_hw_constraint_eld(struct snd_pcm_runtime *runtime, void *eld) | |
| 81 | { | |
| 82 | int ret; | |
| 83 | ||
| 84 | ret = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_RATE, | |
| 85 | eld_limit_rates, eld, | |
| 86 | SNDRV_PCM_HW_PARAM_CHANNELS, -1); | |
| 87 | if (ret < 0) | |
| 88 | return ret; | |
| 89 | ||
| 90 | ret = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_CHANNELS, | |
| 91 | eld_limit_channels, eld, | |
| 92 | SNDRV_PCM_HW_PARAM_RATE, -1); | |
| 93 | ||
| 94 | return ret; | |
| 95 | } | |
| 96 | EXPORT_SYMBOL_GPL(snd_pcm_hw_constraint_eld); |