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); | |
32 | struct snd_interval *c; | |
33 | unsigned int rate_mask = 7, i; | |
34 | const u8 *sad, *eld = rule->private; | |
35 | ||
36 | sad = drm_eld_sad(eld); | |
37 | if (sad) { | |
38 | c = hw_param_interval(params, SNDRV_PCM_HW_PARAM_CHANNELS); | |
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); | |
60 | struct snd_interval *r; | |
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 */ | |
70 | r = hw_param_interval(params, SNDRV_PCM_HW_PARAM_RATE); | |
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); |