mirror of https://github.com/Qortal/Brooklyn
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
96 lines
2.3 KiB
96 lines
2.3 KiB
// SPDX-License-Identifier: GPL-2.0-only |
|
/* |
|
* PCM DRM helpers |
|
*/ |
|
#include <linux/export.h> |
|
#include <drm/drm_edid.h> |
|
#include <sound/pcm.h> |
|
#include <sound/pcm_drm_eld.h> |
|
|
|
static const unsigned int eld_rates[] = { |
|
32000, |
|
44100, |
|
48000, |
|
88200, |
|
96000, |
|
176400, |
|
192000, |
|
}; |
|
|
|
static unsigned int sad_max_channels(const u8 *sad) |
|
{ |
|
return 1 + (sad[0] & 7); |
|
} |
|
|
|
static int eld_limit_rates(struct snd_pcm_hw_params *params, |
|
struct snd_pcm_hw_rule *rule) |
|
{ |
|
struct snd_interval *r = hw_param_interval(params, rule->var); |
|
const struct snd_interval *c; |
|
unsigned int rate_mask = 7, i; |
|
const u8 *sad, *eld = rule->private; |
|
|
|
sad = drm_eld_sad(eld); |
|
if (sad) { |
|
c = hw_param_interval_c(params, SNDRV_PCM_HW_PARAM_CHANNELS); |
|
|
|
for (i = drm_eld_sad_count(eld); i > 0; i--, sad += 3) { |
|
unsigned max_channels = sad_max_channels(sad); |
|
|
|
/* |
|
* Exclude SADs which do not include the |
|
* requested number of channels. |
|
*/ |
|
if (c->min <= max_channels) |
|
rate_mask |= sad[1]; |
|
} |
|
} |
|
|
|
return snd_interval_list(r, ARRAY_SIZE(eld_rates), eld_rates, |
|
rate_mask); |
|
} |
|
|
|
static int eld_limit_channels(struct snd_pcm_hw_params *params, |
|
struct snd_pcm_hw_rule *rule) |
|
{ |
|
struct snd_interval *c = hw_param_interval(params, rule->var); |
|
const struct snd_interval *r; |
|
struct snd_interval t = { .min = 1, .max = 2, .integer = 1, }; |
|
unsigned int i; |
|
const u8 *sad, *eld = rule->private; |
|
|
|
sad = drm_eld_sad(eld); |
|
if (sad) { |
|
unsigned int rate_mask = 0; |
|
|
|
/* Convert the rate interval to a mask */ |
|
r = hw_param_interval_c(params, SNDRV_PCM_HW_PARAM_RATE); |
|
for (i = 0; i < ARRAY_SIZE(eld_rates); i++) |
|
if (r->min <= eld_rates[i] && r->max >= eld_rates[i]) |
|
rate_mask |= BIT(i); |
|
|
|
for (i = drm_eld_sad_count(eld); i > 0; i--, sad += 3) |
|
if (rate_mask & sad[1]) |
|
t.max = max(t.max, sad_max_channels(sad)); |
|
} |
|
|
|
return snd_interval_refine(c, &t); |
|
} |
|
|
|
int snd_pcm_hw_constraint_eld(struct snd_pcm_runtime *runtime, void *eld) |
|
{ |
|
int ret; |
|
|
|
ret = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_RATE, |
|
eld_limit_rates, eld, |
|
SNDRV_PCM_HW_PARAM_CHANNELS, -1); |
|
if (ret < 0) |
|
return ret; |
|
|
|
ret = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_CHANNELS, |
|
eld_limit_channels, eld, |
|
SNDRV_PCM_HW_PARAM_RATE, -1); |
|
|
|
return ret; |
|
} |
|
EXPORT_SYMBOL_GPL(snd_pcm_hw_constraint_eld);
|
|
|