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bcm2835: implement channel map API
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Report all layouts supported by the HDMI protocol to userspace.
Make the videocore set the correct layout according to the
userspace request.

Some code taken from patch_hdmi.c. In particular, the HDMI channel
layout table was copied without changes - with the idea in mind that
hopefully it can be shared one day. Or at least updating it will be
simpler.

In my tests, everything appears to work, except when outputting
FL FR RL RR. Then my receiver outputs RL on both the RL and RR
speakers, while RR is never heard.
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@popcornmix
wm4 authored and popcornmix committed Jan 19, 2016
1 parent 8ac93da commit 103368c
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Showing 4 changed files with 311 additions and 4 deletions.
276 changes: 276 additions & 0 deletions sound/arm/bcm2835-ctl.c
View file
Expand Up @@ -300,6 +300,281 @@ static struct snd_kcontrol_new snd_bcm2835_spdif[] = {
},
};

struct cea_channel_speaker_allocation {
int ca_index;
int speakers[8];
};

#define FL SNDRV_CHMAP_FL
#define FR SNDRV_CHMAP_FR
#define RL SNDRV_CHMAP_RL
#define RR SNDRV_CHMAP_RR
#define LFE SNDRV_CHMAP_LFE
#define FC SNDRV_CHMAP_FC
#define RLC SNDRV_CHMAP_RLC
#define RRC SNDRV_CHMAP_RRC
#define RC SNDRV_CHMAP_RC
#define FLC SNDRV_CHMAP_FLC
#define FRC SNDRV_CHMAP_FRC
#define FLH SNDRV_CHMAP_TFL
#define FRH SNDRV_CHMAP_TFR
#define FLW SNDRV_CHMAP_FLW
#define FRW SNDRV_CHMAP_FRW
#define TC SNDRV_CHMAP_TC
#define FCH SNDRV_CHMAP_TFC

/*
* CEA-861 channel maps
*
* Stolen from sound/pci/hda/patch_hdmi.c
* (unlike the source, this uses SNDRV_* constants directly, as by the
* map_tables array in patch_hdmi.c)
* Unknown entries use 0, which unfortunately is SNDRV_CHMAP_UNKNOWN instead
* of SNDRV_CHMAP_NA.
*/
static struct cea_channel_speaker_allocation channel_allocations[] = {
/* channel: 7 6 5 4 3 2 1 0 */
{ .ca_index = 0x00, .speakers = { 0, 0, 0, 0, 0, 0, FR, FL } },
/* 2.1 */
{ .ca_index = 0x01, .speakers = { 0, 0, 0, 0, 0, LFE, FR, FL } },
/* Dolby Surround */
{ .ca_index = 0x02, .speakers = { 0, 0, 0, 0, FC, 0, FR, FL } },
/* surround40 */
{ .ca_index = 0x08, .speakers = { 0, 0, RR, RL, 0, 0, FR, FL } },
/* surround41 */
{ .ca_index = 0x09, .speakers = { 0, 0, RR, RL, 0, LFE, FR, FL } },
/* surround50 */
{ .ca_index = 0x0a, .speakers = { 0, 0, RR, RL, FC, 0, FR, FL } },
/* surround51 */
{ .ca_index = 0x0b, .speakers = { 0, 0, RR, RL, FC, LFE, FR, FL } },
/* 6.1 */
{ .ca_index = 0x0f, .speakers = { 0, RC, RR, RL, FC, LFE, FR, FL } },
/* surround71 */
{ .ca_index = 0x13, .speakers = { RRC, RLC, RR, RL, FC, LFE, FR, FL } },

{ .ca_index = 0x03, .speakers = { 0, 0, 0, 0, FC, LFE, FR, FL } },
{ .ca_index = 0x04, .speakers = { 0, 0, 0, RC, 0, 0, FR, FL } },
{ .ca_index = 0x05, .speakers = { 0, 0, 0, RC, 0, LFE, FR, FL } },
{ .ca_index = 0x06, .speakers = { 0, 0, 0, RC, FC, 0, FR, FL } },
{ .ca_index = 0x07, .speakers = { 0, 0, 0, RC, FC, LFE, FR, FL } },
{ .ca_index = 0x0c, .speakers = { 0, RC, RR, RL, 0, 0, FR, FL } },
{ .ca_index = 0x0d, .speakers = { 0, RC, RR, RL, 0, LFE, FR, FL } },
{ .ca_index = 0x0e, .speakers = { 0, RC, RR, RL, FC, 0, FR, FL } },
{ .ca_index = 0x10, .speakers = { RRC, RLC, RR, RL, 0, 0, FR, FL } },
{ .ca_index = 0x11, .speakers = { RRC, RLC, RR, RL, 0, LFE, FR, FL } },
{ .ca_index = 0x12, .speakers = { RRC, RLC, RR, RL, FC, 0, FR, FL } },
{ .ca_index = 0x14, .speakers = { FRC, FLC, 0, 0, 0, 0, FR, FL } },
{ .ca_index = 0x15, .speakers = { FRC, FLC, 0, 0, 0, LFE, FR, FL } },
{ .ca_index = 0x16, .speakers = { FRC, FLC, 0, 0, FC, 0, FR, FL } },
{ .ca_index = 0x17, .speakers = { FRC, FLC, 0, 0, FC, LFE, FR, FL } },
{ .ca_index = 0x18, .speakers = { FRC, FLC, 0, RC, 0, 0, FR, FL } },
{ .ca_index = 0x19, .speakers = { FRC, FLC, 0, RC, 0, LFE, FR, FL } },
{ .ca_index = 0x1a, .speakers = { FRC, FLC, 0, RC, FC, 0, FR, FL } },
{ .ca_index = 0x1b, .speakers = { FRC, FLC, 0, RC, FC, LFE, FR, FL } },
{ .ca_index = 0x1c, .speakers = { FRC, FLC, RR, RL, 0, 0, FR, FL } },
{ .ca_index = 0x1d, .speakers = { FRC, FLC, RR, RL, 0, LFE, FR, FL } },
{ .ca_index = 0x1e, .speakers = { FRC, FLC, RR, RL, FC, 0, FR, FL } },
{ .ca_index = 0x1f, .speakers = { FRC, FLC, RR, RL, FC, LFE, FR, FL } },
{ .ca_index = 0x20, .speakers = { 0, FCH, RR, RL, FC, 0, FR, FL } },
{ .ca_index = 0x21, .speakers = { 0, FCH, RR, RL, FC, LFE, FR, FL } },
{ .ca_index = 0x22, .speakers = { TC, 0, RR, RL, FC, 0, FR, FL } },
{ .ca_index = 0x23, .speakers = { TC, 0, RR, RL, FC, LFE, FR, FL } },
{ .ca_index = 0x24, .speakers = { FRH, FLH, RR, RL, 0, 0, FR, FL } },
{ .ca_index = 0x25, .speakers = { FRH, FLH, RR, RL, 0, LFE, FR, FL } },
{ .ca_index = 0x26, .speakers = { FRW, FLW, RR, RL, 0, 0, FR, FL } },
{ .ca_index = 0x27, .speakers = { FRW, FLW, RR, RL, 0, LFE, FR, FL } },
{ .ca_index = 0x28, .speakers = { TC, RC, RR, RL, FC, 0, FR, FL } },
{ .ca_index = 0x29, .speakers = { TC, RC, RR, RL, FC, LFE, FR, FL } },
{ .ca_index = 0x2a, .speakers = { FCH, RC, RR, RL, FC, 0, FR, FL } },
{ .ca_index = 0x2b, .speakers = { FCH, RC, RR, RL, FC, LFE, FR, FL } },
{ .ca_index = 0x2c, .speakers = { TC, FCH, RR, RL, FC, 0, FR, FL } },
{ .ca_index = 0x2d, .speakers = { TC, FCH, RR, RL, FC, LFE, FR, FL } },
{ .ca_index = 0x2e, .speakers = { FRH, FLH, RR, RL, FC, 0, FR, FL } },
{ .ca_index = 0x2f, .speakers = { FRH, FLH, RR, RL, FC, LFE, FR, FL } },
{ .ca_index = 0x30, .speakers = { FRW, FLW, RR, RL, FC, 0, FR, FL } },
{ .ca_index = 0x31, .speakers = { FRW, FLW, RR, RL, FC, LFE, FR, FL } },
};

static int snd_bcm2835_chmap_ctl_tlv(struct snd_kcontrol *kcontrol, int op_flag,
unsigned int size, unsigned int __user *tlv)
{
unsigned int __user *dst;
int count = 0;
int i;

if (size < 8)
return -ENOMEM;
if (put_user(SNDRV_CTL_TLVT_CONTAINER, tlv))
return -EFAULT;
size -= 8;
dst = tlv + 2;
for (i = 0; i < ARRAY_SIZE(channel_allocations); i++) {
struct cea_channel_speaker_allocation *ch = &channel_allocations[i];
int num_chs = 0;
int chs_bytes;
int c;

for (c = 0; c < 8; c++) {
if (ch->speakers[c])
num_chs++;
}

chs_bytes = num_chs * 4;
if (size < 8)
return -ENOMEM;
if (put_user(SNDRV_CTL_TLVT_CHMAP_FIXED, dst) ||
put_user(chs_bytes, dst + 1))
return -EFAULT;
dst += 2;
size -= 8;
count += 8;
if (size < chs_bytes)
return -ENOMEM;
size -= chs_bytes;
count += chs_bytes;
for (c = 0; c < 8; c++) {
int sp = ch->speakers[7 - c];
if (sp) {
if (put_user(sp, dst))
return -EFAULT;
dst++;
}
}
}
if (put_user(count, tlv + 1))
return -EFAULT;
return 0;
}

static int snd_bcm2835_chmap_ctl_get(struct snd_kcontrol *kcontrol,
struct snd_ctl_elem_value *ucontrol)
{
struct snd_pcm_chmap *info = snd_kcontrol_chip(kcontrol);
bcm2835_chip_t *chip = info->private_data;
unsigned int idx = snd_ctl_get_ioffidx(kcontrol, &ucontrol->id);
struct snd_pcm_substream *substream = snd_pcm_chmap_substream(info, idx);
struct cea_channel_speaker_allocation *ch = NULL;
int cur = 0;
int i;

if (!substream || !substream->runtime)
return -ENODEV;

for (i = 0; i < ARRAY_SIZE(channel_allocations); i++) {
if (channel_allocations[i].ca_index == chip->cea_chmap)
ch = &channel_allocations[i];
}

/* If no layout was set yet, return a dummy. Apparently the userspace
* API will be confused if we don't. */
if (!ch)
ch = &channel_allocations[0];

for (i = 0; i < 8; i++) {
if (ch->speakers[7 - i])
ucontrol->value.integer.value[cur++] = ch->speakers[7 - i];
}
while (cur < 8)
ucontrol->value.integer.value[cur++] = SNDRV_CHMAP_NA;
return 0;
}

static int snd_bcm2835_chmap_ctl_put(struct snd_kcontrol *kcontrol,
struct snd_ctl_elem_value *ucontrol)
{
struct snd_pcm_chmap *info = snd_kcontrol_chip(kcontrol);
bcm2835_chip_t *chip = info->private_data;
unsigned int idx = snd_ctl_get_ioffidx(kcontrol, &ucontrol->id);
struct snd_pcm_substream *substream = snd_pcm_chmap_substream(info, idx);
int i, prepared = 0, cea_chmap = -1;
int remap[8];

if (!substream || !substream->runtime)
return -ENODEV;

switch (substream->runtime->status->state) {
case SNDRV_PCM_STATE_OPEN:
case SNDRV_PCM_STATE_SETUP:
break;
case SNDRV_PCM_STATE_PREPARED:
prepared = 1;
break;
default:
return -EBUSY;
}

for (i = 0; i < ARRAY_SIZE(channel_allocations); i++) {
struct cea_channel_speaker_allocation *ch = &channel_allocations[i];
int matches = 1;
int cur = 0;
int x;
memset(remap, 0, sizeof(remap));
for (x = 0; x < substream->runtime->channels; x++) {
int sp = ucontrol->value.integer.value[x];
while (cur < 8 && !ch->speakers[7 - cur])
cur++;
if (cur >= 8) {
/* user has more channels than ch */
matches = 0;
break;
}
if (ch->speakers[7 - cur] != sp) {
matches = 0;
break;
}
remap[x] = cur;
cur++;
}
for (x = cur; x < 8; x++) {
if (ch->speakers[7 - x]) {
/* ch has more channels than user */
matches = 0;
break;
}
}
if (matches) {
cea_chmap = ch->ca_index;
break;
}
}

if (cea_chmap < 0)
return -EINVAL;

/* don't change the layout if another substream is active */
if (chip->opened != (1 << substream->number) && chip->cea_chmap != cea_chmap)
return -EBUSY; /* unsure whether this is a good error code */

chip->cea_chmap = cea_chmap;
for (i = 0; i < 8; i++)
chip->map_channels[i] = remap[i];
if (prepared)
snd_bcm2835_pcm_prepare_again(substream);
return 0;
}

static int snd_bcm2835_add_chmap_ctl(bcm2835_chip_t * chip)
{
struct snd_pcm_chmap *chmap;
struct snd_kcontrol *kctl;
int err, i;

err = snd_pcm_add_chmap_ctls(chip->pcm,
SNDRV_PCM_STREAM_PLAYBACK,
NULL, 8, 0, &chmap);
if (err < 0)
return err;
/* override handlers */
chmap->private_data = chip;
kctl = chmap->kctl;
for (i = 0; i < kctl->count; i++)
kctl->vd[i].access |= SNDRV_CTL_ELEM_ACCESS_WRITE;
kctl->get = snd_bcm2835_chmap_ctl_get;
kctl->put = snd_bcm2835_chmap_ctl_put;
kctl->tlv.c = snd_bcm2835_chmap_ctl_tlv;
return 0;
}

int snd_bcm2835_new_ctl(bcm2835_chip_t * chip)
{
int err;
Expand All @@ -313,6 +588,7 @@ int snd_bcm2835_new_ctl(bcm2835_chip_t * chip)
if (err < 0)
return err;
}
snd_bcm2835_add_chmap_ctl(chip);
for (idx = 0; idx < ARRAY_SIZE(snd_bcm2835_spdif); idx++) {
err = snd_ctl_add(chip->card,
snd_ctl_new1(&snd_bcm2835_spdif[idx], chip));
Expand Down
22 changes: 18 additions & 4 deletions sound/arm/bcm2835-pcm.c
View file
Expand Up @@ -231,6 +231,9 @@ static int snd_bcm2835_playback_open_generic(

chip->alsa_stream[idx] = alsa_stream;

if (!chip->opened)
chip->cea_chmap = -1;

chip->opened |= (1 << idx);
alsa_stream->open = 1;
alsa_stream->draining = 1;
Expand Down Expand Up @@ -341,17 +344,14 @@ static int snd_bcm2835_pcm_hw_free(struct snd_pcm_substream *substream)
return snd_pcm_lib_free_pages(substream);
}

/* prepare callback */
static int snd_bcm2835_pcm_prepare(struct snd_pcm_substream *substream)
int snd_bcm2835_pcm_prepare_again(struct snd_pcm_substream *substream)
{
bcm2835_chip_t *chip = snd_pcm_substream_chip(substream);
struct snd_pcm_runtime *runtime = substream->runtime;
bcm2835_alsa_stream_t *alsa_stream = runtime->private_data;
int channels;
int err;

audio_info(" .. IN\n");

/* notify the vchiq that it should enter spdif passthrough mode by
* setting channels=0 (see
* https://github.com/raspberrypi/linux/issues/528) */
Expand All @@ -367,6 +367,20 @@ static int snd_bcm2835_pcm_prepare(struct snd_pcm_substream *substream)
audio_error(" error setting hw params\n");
}

return err;
}

/* prepare callback */
static int snd_bcm2835_pcm_prepare(struct snd_pcm_substream *substream)
{
bcm2835_chip_t *chip = snd_pcm_substream_chip(substream);
struct snd_pcm_runtime *runtime = substream->runtime;
bcm2835_alsa_stream_t *alsa_stream = runtime->private_data;

audio_info(" .. IN\n");

snd_bcm2835_pcm_prepare_again(substream);

bcm2835_audio_setup(alsa_stream);

/* in preparation of the stream, set the controls (volume level) of the stream */
Expand Down
13 changes: 13 additions & 0 deletions sound/arm/bcm2835-vchiq.c
View file
Expand Up @@ -570,6 +570,8 @@ int bcm2835_audio_set_params(bcm2835_alsa_stream_t * alsa_stream,
VC_AUDIO_MSG_T m;
AUDIO_INSTANCE_T *instance = alsa_stream->instance;
int32_t success;
uint32_t chmap_value;
int i;
int ret;
LOG_DBG(" .. IN\n");

Expand All @@ -593,10 +595,21 @@ int bcm2835_audio_set_params(bcm2835_alsa_stream_t * alsa_stream,

instance->result = -1;

if (alsa_stream->chip->cea_chmap >= 0) {
chmap_value = (unsigned)alsa_stream->chip->cea_chmap << 24;
} else {
chmap_value = 0; /* force stereo */
for (i = 0; i < 8; i++)
alsa_stream->chip->map_channels[i] = i;
}
for (i = 0; i < 8; i++)
chmap_value |= alsa_stream->chip->map_channels[i] << (i * 3);

m.type = VC_AUDIO_MSG_TYPE_CONFIG;
m.u.config.channels = channels;
m.u.config.samplerate = samplerate;
m.u.config.bps = bps;
m.u.config.channelmap = chmap_value;

/* Create the message available completion */
init_completion(&instance->msg_avail_comp);
Expand Down
4 changes: 4 additions & 0 deletions sound/arm/bcm2835.h
View file
Expand Up @@ -107,6 +107,8 @@ typedef struct bcm2835_chip {
int old_volume; /* stores the volume value whist muted */
int dest;
int mute;
int cea_chmap; /* currently requested Audio InfoFrame Data Byte 4 */
int map_channels[8];

unsigned int opened;
unsigned int spdif_status;
Expand Down Expand Up @@ -149,6 +151,8 @@ int snd_bcm2835_new_ctl(bcm2835_chip_t * chip);
int snd_bcm2835_new_pcm(bcm2835_chip_t * chip);
int snd_bcm2835_new_spdif_pcm(bcm2835_chip_t * chip);

int snd_bcm2835_pcm_prepare_again(struct snd_pcm_substream *substream);

int bcm2835_audio_open(bcm2835_alsa_stream_t * alsa_stream);
int bcm2835_audio_close(bcm2835_alsa_stream_t * alsa_stream);
int bcm2835_audio_set_params(bcm2835_alsa_stream_t * alsa_stream,
Expand Down

1 comment on commit 103368c

@clivem
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@clivem clivem commented on 103368c Jan 21, 2016

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I wonder whether the "no such device" errors are related to the channel map changes?

$ amixer -c0 controls
numid=3,iface=MIXER,name='PCM Playback Route'
numid=2,iface=MIXER,name='PCM Playback Switch'
numid=1,iface=MIXER,name='PCM Playback Volume'
numid=13,iface=PCM,name='IEC958 Playback Con Mask'
numid=12,iface=PCM,name='IEC958 Playback Default'
numid=4,iface=PCM,name='Playback Channel Map'
numid=5,iface=PCM,name='Playback Channel Map',index=1
numid=6,iface=PCM,name='Playback Channel Map',index=2
numid=7,iface=PCM,name='Playback Channel Map',index=3
numid=8,iface=PCM,name='Playback Channel Map',index=4
numid=9,iface=PCM,name='Playback Channel Map',index=5
numid=10,iface=PCM,name='Playback Channel Map',index=6
numid=11,iface=PCM,name='Playback Channel Map',index=7
$ amixer -c0 contents
numid=3,iface=MIXER,name='PCM Playback Route'
; type=INTEGER,access=rw------,values=1,min=0,max=2,step=0
: values=0
numid=2,iface=MIXER,name='PCM Playback Switch'
; type=BOOLEAN,access=rw------,values=1
: values=on
numid=1,iface=MIXER,name='PCM Playback Volume'
; type=INTEGER,access=rw---R--,values=1,min=-10239,max=400,step=0
: values=400
| dBscale-min=-102.39dB,step=0.01dB,mute=1
numid=13,iface=PCM,name='IEC958 Playback Con Mask'
; type=IEC958,access=r-------,values=1
: values=[AES0=0x02 AES1=0x00 AES2=0x00 AES3=0x00]
numid=12,iface=PCM,name='IEC958 Playback Default'
; type=IEC958,access=rw------,values=1
: values=[AES0=0x00 AES1=0x00 AES2=0x00 AES3=0x00]

numid=4,iface=PCM,name='Playback Channel Map'
; type=INTEGER,access=rw---R--,values=8,min=0,max=36,step=0
amixer: Control hw:0 element read error: No such device

numid=5,iface=PCM,name='Playback Channel Map',index=1
; type=INTEGER,access=rw---R--,values=8,min=0,max=36,step=0
amixer: Control hw:0 element read error: No such device

numid=6,iface=PCM,name='Playback Channel Map',index=2
; type=INTEGER,access=rw---R--,values=8,min=0,max=36,step=0
amixer: Control hw:0 element read error: No such device

numid=7,iface=PCM,name='Playback Channel Map',index=3
; type=INTEGER,access=rw---R--,values=8,min=0,max=36,step=0
amixer: Control hw:0 element read error: No such device

numid=8,iface=PCM,name='Playback Channel Map',index=4
; type=INTEGER,access=rw---R--,values=8,min=0,max=36,step=0
amixer: Control hw:0 element read error: No such device

numid=9,iface=PCM,name='Playback Channel Map',index=5
; type=INTEGER,access=rw---R--,values=8,min=0,max=36,step=0
amixer: Control hw:0 element read error: No such device

numid=10,iface=PCM,name='Playback Channel Map',index=6
; type=INTEGER,access=rw---R--,values=8,min=0,max=36,step=0
amixer: Control hw:0 element read error: No such device

numid=11,iface=PCM,name='Playback Channel Map',index=7
; type=INTEGER,access=rw---R--,values=8,min=0,max=36,step=0
amixer: Control hw:0 element read error: No such device

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