blob: 07075071972dd76031ec61fe7b7c1af1cb06d1ba [file] [log] [blame]
// SPDX-License-Identifier: GPL-2.0-only
/*
* PCM DRM helpers
*/
#include <linux/bitfield.h>
#include <linux/export.h>
#include <linux/hdmi.h>
#include <drm/drm_edid.h>
#include <sound/pcm.h>
#include <sound/pcm_drm_eld.h>
#define SAD0_CHANNELS_MASK GENMASK(2, 0) /* max number of channels - 1 */
#define SAD0_FORMAT_MASK GENMASK(6, 3) /* audio format */
#define SAD1_RATE_MASK GENMASK(6, 0) /* bitfield of supported rates */
#define SAD1_RATE_32000_MASK BIT(0)
#define SAD1_RATE_44100_MASK BIT(1)
#define SAD1_RATE_48000_MASK BIT(2)
#define SAD1_RATE_88200_MASK BIT(3)
#define SAD1_RATE_96000_MASK BIT(4)
#define SAD1_RATE_176400_MASK BIT(5)
#define SAD1_RATE_192000_MASK BIT(6)
static const unsigned int eld_rates[] = {
32000,
44100,
48000,
88200,
96000,
176400,
192000,
};
static unsigned int map_rate_families(const u8 *sad,
unsigned int mask_32000,
unsigned int mask_44100,
unsigned int mask_48000)
{
unsigned int rate_mask = 0;
if (sad[1] & SAD1_RATE_32000_MASK)
rate_mask |= mask_32000;
if (sad[1] & (SAD1_RATE_44100_MASK | SAD1_RATE_88200_MASK | SAD1_RATE_176400_MASK))
rate_mask |= mask_44100;
if (sad[1] & (SAD1_RATE_48000_MASK | SAD1_RATE_96000_MASK | SAD1_RATE_192000_MASK))
rate_mask |= mask_48000;
return rate_mask;
}
static unsigned int sad_rate_mask(const u8 *sad)
{
switch (FIELD_GET(SAD0_FORMAT_MASK, sad[0])) {
case HDMI_AUDIO_CODING_TYPE_PCM:
return sad[1] & SAD1_RATE_MASK;
case HDMI_AUDIO_CODING_TYPE_AC3:
case HDMI_AUDIO_CODING_TYPE_DTS:
return map_rate_families(sad,
SAD1_RATE_32000_MASK,
SAD1_RATE_44100_MASK,
SAD1_RATE_48000_MASK);
case HDMI_AUDIO_CODING_TYPE_EAC3:
case HDMI_AUDIO_CODING_TYPE_DTS_HD:
case HDMI_AUDIO_CODING_TYPE_MLP:
return map_rate_families(sad,
0,
SAD1_RATE_176400_MASK,
SAD1_RATE_192000_MASK);
default:
/* TODO adjust for other compressed formats as well */
return sad[1] & SAD1_RATE_MASK;
}
}
static unsigned int sad_max_channels(const u8 *sad)
{
switch (FIELD_GET(SAD0_FORMAT_MASK, sad[0])) {
case HDMI_AUDIO_CODING_TYPE_PCM:
return 1 + FIELD_GET(SAD0_CHANNELS_MASK, sad[0]);
case HDMI_AUDIO_CODING_TYPE_AC3:
case HDMI_AUDIO_CODING_TYPE_DTS:
case HDMI_AUDIO_CODING_TYPE_EAC3:
return 2;
case HDMI_AUDIO_CODING_TYPE_DTS_HD:
case HDMI_AUDIO_CODING_TYPE_MLP:
return 8;
default:
/* TODO adjust for other compressed formats as well */
return 1 + FIELD_GET(SAD0_CHANNELS_MASK, sad[0]);
}
}
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_rate_mask(sad);
}
}
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_rate_mask(sad))
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);