linux/sound/firewire/fireface/ff-pcm.c

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ALSA: fireface: add support for PCM functionality This commit adds PCM functionality to transmit/receive PCM frames on isochronous packet streaming. This commit enables userspace applications to start/stop packet streaming via ALSA PCM interface. Sampling rate requested by applications is used as sampling transmission frequency of IEC 61883-1/6packet streaming. As I described in followed commits, units in this series manages sampling clock frequency independently of sampling transmission frequency, and they supports resampling between their packet streaming/data block processing layer and sampling data processing layer. This commit take this driver to utilize these features for usability. When internal clock is selected as source signal of sampling clock, this driver allows user space applications to start PCM substreams at any rate which packet streaming engine supports as sampling transmission frequency. In this case, this driver expects units to perform resampling PCM frames for rx/tx packets when sampling clock frequency and sampling transmission frequency are mismatched. This is for daily use cases. When any external clock is selected as the source signal, this driver gets configured sampling rate from units, then restricts available sampling rate to the rate for PCM applications. This is for studio use cases. Models in this series supports 64.0/128.0 kHz of sampling rate, however these frequencies are not supported by IEC 61883-6 as sampling transmission frequency. Therefore, packet streaming engine of ALSA firewire stack can't handle them. When units are configured to use any external clock as source signal of sampling clock and one of these unsupported rate is configured as rate of the sampling clock, this driver returns EIO to user space applications. Anyway, this driver doesn't voluntarily configure parameters of sampling clock. It's better for users to work with appropriate user space implementations to configure the parameters in advance of usage. Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2017-03-31 21:06:10 +08:00
/*
* ff-pcm.c - a part of driver for RME Fireface series
*
* Copyright (c) 2015-2017 Takashi Sakamoto
*
* Licensed under the terms of the GNU General Public License, version 2.
*/
#include "ff.h"
static inline unsigned int get_multiplier_mode_with_index(unsigned int index)
{
return ((int)index - 1) / 2;
}
static int hw_rule_rate(struct snd_pcm_hw_params *params,
struct snd_pcm_hw_rule *rule)
{
const unsigned int *pcm_channels = rule->private;
struct snd_interval *r =
hw_param_interval(params, SNDRV_PCM_HW_PARAM_RATE);
const struct snd_interval *c =
hw_param_interval_c(params, SNDRV_PCM_HW_PARAM_CHANNELS);
struct snd_interval t = {
.min = UINT_MAX, .max = 0, .integer = 1
};
unsigned int i, mode;
for (i = 0; i < ARRAY_SIZE(amdtp_rate_table); i++) {
mode = get_multiplier_mode_with_index(i);
if (!snd_interval_test(c, pcm_channels[mode]))
continue;
t.min = min(t.min, amdtp_rate_table[i]);
t.max = max(t.max, amdtp_rate_table[i]);
}
return snd_interval_refine(r, &t);
}
static int hw_rule_channels(struct snd_pcm_hw_params *params,
struct snd_pcm_hw_rule *rule)
{
const unsigned int *pcm_channels = rule->private;
struct snd_interval *c =
hw_param_interval(params, SNDRV_PCM_HW_PARAM_CHANNELS);
const struct snd_interval *r =
hw_param_interval_c(params, SNDRV_PCM_HW_PARAM_RATE);
struct snd_interval t = {
.min = UINT_MAX, .max = 0, .integer = 1
};
unsigned int i, mode;
for (i = 0; i < ARRAY_SIZE(amdtp_rate_table); i++) {
mode = get_multiplier_mode_with_index(i);
if (!snd_interval_test(r, amdtp_rate_table[i]))
continue;
t.min = min(t.min, pcm_channels[mode]);
t.max = max(t.max, pcm_channels[mode]);
}
return snd_interval_refine(c, &t);
}
static void limit_channels_and_rates(struct snd_pcm_hardware *hw,
const unsigned int *pcm_channels)
{
unsigned int mode;
unsigned int rate, channels;
int i;
hw->channels_min = UINT_MAX;
hw->channels_max = 0;
hw->rate_min = UINT_MAX;
hw->rate_max = 0;
for (i = 0; i < ARRAY_SIZE(amdtp_rate_table); i++) {
mode = get_multiplier_mode_with_index(i);
channels = pcm_channels[mode];
if (pcm_channels[mode] == 0)
continue;
hw->channels_min = min(hw->channels_min, channels);
hw->channels_max = max(hw->channels_max, channels);
rate = amdtp_rate_table[i];
hw->rates |= snd_pcm_rate_to_rate_bit(rate);
hw->rate_min = min(hw->rate_min, rate);
hw->rate_max = max(hw->rate_max, rate);
}
}
static int pcm_init_hw_params(struct snd_ff *ff,
struct snd_pcm_substream *substream)
{
struct snd_pcm_runtime *runtime = substream->runtime;
struct amdtp_stream *s;
const unsigned int *pcm_channels;
int err;
if (substream->stream == SNDRV_PCM_STREAM_CAPTURE) {
runtime->hw.formats = SNDRV_PCM_FMTBIT_S32;
s = &ff->tx_stream;
pcm_channels = ff->spec->pcm_capture_channels;
} else {
runtime->hw.formats = SNDRV_PCM_FMTBIT_S32;
s = &ff->rx_stream;
pcm_channels = ff->spec->pcm_playback_channels;
}
limit_channels_and_rates(&runtime->hw, pcm_channels);
err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_CHANNELS,
hw_rule_channels, (void *)pcm_channels,
SNDRV_PCM_HW_PARAM_RATE, -1);
if (err < 0)
return err;
err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_RATE,
hw_rule_rate, (void *)pcm_channels,
SNDRV_PCM_HW_PARAM_CHANNELS, -1);
if (err < 0)
return err;
return amdtp_ff_add_pcm_hw_constraints(s, runtime);
}
static int pcm_open(struct snd_pcm_substream *substream)
{
struct snd_ff *ff = substream->private_data;
unsigned int rate;
enum snd_ff_clock_src src;
int i, err;
err = snd_ff_stream_lock_try(ff);
ALSA: fireface: add support for PCM functionality This commit adds PCM functionality to transmit/receive PCM frames on isochronous packet streaming. This commit enables userspace applications to start/stop packet streaming via ALSA PCM interface. Sampling rate requested by applications is used as sampling transmission frequency of IEC 61883-1/6packet streaming. As I described in followed commits, units in this series manages sampling clock frequency independently of sampling transmission frequency, and they supports resampling between their packet streaming/data block processing layer and sampling data processing layer. This commit take this driver to utilize these features for usability. When internal clock is selected as source signal of sampling clock, this driver allows user space applications to start PCM substreams at any rate which packet streaming engine supports as sampling transmission frequency. In this case, this driver expects units to perform resampling PCM frames for rx/tx packets when sampling clock frequency and sampling transmission frequency are mismatched. This is for daily use cases. When any external clock is selected as the source signal, this driver gets configured sampling rate from units, then restricts available sampling rate to the rate for PCM applications. This is for studio use cases. Models in this series supports 64.0/128.0 kHz of sampling rate, however these frequencies are not supported by IEC 61883-6 as sampling transmission frequency. Therefore, packet streaming engine of ALSA firewire stack can't handle them. When units are configured to use any external clock as source signal of sampling clock and one of these unsupported rate is configured as rate of the sampling clock, this driver returns EIO to user space applications. Anyway, this driver doesn't voluntarily configure parameters of sampling clock. It's better for users to work with appropriate user space implementations to configure the parameters in advance of usage. Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2017-03-31 21:06:10 +08:00
if (err < 0)
return err;
err = pcm_init_hw_params(ff, substream);
if (err < 0)
goto release_lock;
ALSA: fireface: add support for PCM functionality This commit adds PCM functionality to transmit/receive PCM frames on isochronous packet streaming. This commit enables userspace applications to start/stop packet streaming via ALSA PCM interface. Sampling rate requested by applications is used as sampling transmission frequency of IEC 61883-1/6packet streaming. As I described in followed commits, units in this series manages sampling clock frequency independently of sampling transmission frequency, and they supports resampling between their packet streaming/data block processing layer and sampling data processing layer. This commit take this driver to utilize these features for usability. When internal clock is selected as source signal of sampling clock, this driver allows user space applications to start PCM substreams at any rate which packet streaming engine supports as sampling transmission frequency. In this case, this driver expects units to perform resampling PCM frames for rx/tx packets when sampling clock frequency and sampling transmission frequency are mismatched. This is for daily use cases. When any external clock is selected as the source signal, this driver gets configured sampling rate from units, then restricts available sampling rate to the rate for PCM applications. This is for studio use cases. Models in this series supports 64.0/128.0 kHz of sampling rate, however these frequencies are not supported by IEC 61883-6 as sampling transmission frequency. Therefore, packet streaming engine of ALSA firewire stack can't handle them. When units are configured to use any external clock as source signal of sampling clock and one of these unsupported rate is configured as rate of the sampling clock, this driver returns EIO to user space applications. Anyway, this driver doesn't voluntarily configure parameters of sampling clock. It's better for users to work with appropriate user space implementations to configure the parameters in advance of usage. Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2017-03-31 21:06:10 +08:00
err = ff->spec->protocol->get_clock(ff, &rate, &src);
if (err < 0)
goto release_lock;
ALSA: fireface: add support for PCM functionality This commit adds PCM functionality to transmit/receive PCM frames on isochronous packet streaming. This commit enables userspace applications to start/stop packet streaming via ALSA PCM interface. Sampling rate requested by applications is used as sampling transmission frequency of IEC 61883-1/6packet streaming. As I described in followed commits, units in this series manages sampling clock frequency independently of sampling transmission frequency, and they supports resampling between their packet streaming/data block processing layer and sampling data processing layer. This commit take this driver to utilize these features for usability. When internal clock is selected as source signal of sampling clock, this driver allows user space applications to start PCM substreams at any rate which packet streaming engine supports as sampling transmission frequency. In this case, this driver expects units to perform resampling PCM frames for rx/tx packets when sampling clock frequency and sampling transmission frequency are mismatched. This is for daily use cases. When any external clock is selected as the source signal, this driver gets configured sampling rate from units, then restricts available sampling rate to the rate for PCM applications. This is for studio use cases. Models in this series supports 64.0/128.0 kHz of sampling rate, however these frequencies are not supported by IEC 61883-6 as sampling transmission frequency. Therefore, packet streaming engine of ALSA firewire stack can't handle them. When units are configured to use any external clock as source signal of sampling clock and one of these unsupported rate is configured as rate of the sampling clock, this driver returns EIO to user space applications. Anyway, this driver doesn't voluntarily configure parameters of sampling clock. It's better for users to work with appropriate user space implementations to configure the parameters in advance of usage. Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2017-03-31 21:06:10 +08:00
if (src != SND_FF_CLOCK_SRC_INTERNAL) {
for (i = 0; i < CIP_SFC_COUNT; ++i) {
if (amdtp_rate_table[i] == rate)
break;
}
/*
* The unit is configured at sampling frequency which packet
* streaming engine can't support.
*/
if (i >= CIP_SFC_COUNT) {
err = -EIO;
goto release_lock;
}
ALSA: fireface: add support for PCM functionality This commit adds PCM functionality to transmit/receive PCM frames on isochronous packet streaming. This commit enables userspace applications to start/stop packet streaming via ALSA PCM interface. Sampling rate requested by applications is used as sampling transmission frequency of IEC 61883-1/6packet streaming. As I described in followed commits, units in this series manages sampling clock frequency independently of sampling transmission frequency, and they supports resampling between their packet streaming/data block processing layer and sampling data processing layer. This commit take this driver to utilize these features for usability. When internal clock is selected as source signal of sampling clock, this driver allows user space applications to start PCM substreams at any rate which packet streaming engine supports as sampling transmission frequency. In this case, this driver expects units to perform resampling PCM frames for rx/tx packets when sampling clock frequency and sampling transmission frequency are mismatched. This is for daily use cases. When any external clock is selected as the source signal, this driver gets configured sampling rate from units, then restricts available sampling rate to the rate for PCM applications. This is for studio use cases. Models in this series supports 64.0/128.0 kHz of sampling rate, however these frequencies are not supported by IEC 61883-6 as sampling transmission frequency. Therefore, packet streaming engine of ALSA firewire stack can't handle them. When units are configured to use any external clock as source signal of sampling clock and one of these unsupported rate is configured as rate of the sampling clock, this driver returns EIO to user space applications. Anyway, this driver doesn't voluntarily configure parameters of sampling clock. It's better for users to work with appropriate user space implementations to configure the parameters in advance of usage. Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2017-03-31 21:06:10 +08:00
substream->runtime->hw.rate_min = rate;
substream->runtime->hw.rate_max = rate;
} else {
if (amdtp_stream_pcm_running(&ff->rx_stream) ||
amdtp_stream_pcm_running(&ff->tx_stream)) {
rate = amdtp_rate_table[ff->rx_stream.sfc];
substream->runtime->hw.rate_min = rate;
substream->runtime->hw.rate_max = rate;
}
}
snd_pcm_set_sync(substream);
return 0;
release_lock:
snd_ff_stream_lock_release(ff);
return err;
ALSA: fireface: add support for PCM functionality This commit adds PCM functionality to transmit/receive PCM frames on isochronous packet streaming. This commit enables userspace applications to start/stop packet streaming via ALSA PCM interface. Sampling rate requested by applications is used as sampling transmission frequency of IEC 61883-1/6packet streaming. As I described in followed commits, units in this series manages sampling clock frequency independently of sampling transmission frequency, and they supports resampling between their packet streaming/data block processing layer and sampling data processing layer. This commit take this driver to utilize these features for usability. When internal clock is selected as source signal of sampling clock, this driver allows user space applications to start PCM substreams at any rate which packet streaming engine supports as sampling transmission frequency. In this case, this driver expects units to perform resampling PCM frames for rx/tx packets when sampling clock frequency and sampling transmission frequency are mismatched. This is for daily use cases. When any external clock is selected as the source signal, this driver gets configured sampling rate from units, then restricts available sampling rate to the rate for PCM applications. This is for studio use cases. Models in this series supports 64.0/128.0 kHz of sampling rate, however these frequencies are not supported by IEC 61883-6 as sampling transmission frequency. Therefore, packet streaming engine of ALSA firewire stack can't handle them. When units are configured to use any external clock as source signal of sampling clock and one of these unsupported rate is configured as rate of the sampling clock, this driver returns EIO to user space applications. Anyway, this driver doesn't voluntarily configure parameters of sampling clock. It's better for users to work with appropriate user space implementations to configure the parameters in advance of usage. Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2017-03-31 21:06:10 +08:00
}
static int pcm_close(struct snd_pcm_substream *substream)
{
struct snd_ff *ff = substream->private_data;
snd_ff_stream_lock_release(ff);
ALSA: fireface: add support for PCM functionality This commit adds PCM functionality to transmit/receive PCM frames on isochronous packet streaming. This commit enables userspace applications to start/stop packet streaming via ALSA PCM interface. Sampling rate requested by applications is used as sampling transmission frequency of IEC 61883-1/6packet streaming. As I described in followed commits, units in this series manages sampling clock frequency independently of sampling transmission frequency, and they supports resampling between their packet streaming/data block processing layer and sampling data processing layer. This commit take this driver to utilize these features for usability. When internal clock is selected as source signal of sampling clock, this driver allows user space applications to start PCM substreams at any rate which packet streaming engine supports as sampling transmission frequency. In this case, this driver expects units to perform resampling PCM frames for rx/tx packets when sampling clock frequency and sampling transmission frequency are mismatched. This is for daily use cases. When any external clock is selected as the source signal, this driver gets configured sampling rate from units, then restricts available sampling rate to the rate for PCM applications. This is for studio use cases. Models in this series supports 64.0/128.0 kHz of sampling rate, however these frequencies are not supported by IEC 61883-6 as sampling transmission frequency. Therefore, packet streaming engine of ALSA firewire stack can't handle them. When units are configured to use any external clock as source signal of sampling clock and one of these unsupported rate is configured as rate of the sampling clock, this driver returns EIO to user space applications. Anyway, this driver doesn't voluntarily configure parameters of sampling clock. It's better for users to work with appropriate user space implementations to configure the parameters in advance of usage. Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2017-03-31 21:06:10 +08:00
return 0;
}
static int pcm_capture_hw_params(struct snd_pcm_substream *substream,
struct snd_pcm_hw_params *hw_params)
{
struct snd_ff *ff = substream->private_data;
int err;
err = snd_pcm_lib_alloc_vmalloc_buffer(substream,
params_buffer_bytes(hw_params));
if (err < 0)
return err;
if (substream->runtime->status->state == SNDRV_PCM_STATE_OPEN) {
mutex_lock(&ff->mutex);
ff->substreams_counter++;
mutex_unlock(&ff->mutex);
}
return 0;
}
static int pcm_playback_hw_params(struct snd_pcm_substream *substream,
struct snd_pcm_hw_params *hw_params)
{
struct snd_ff *ff = substream->private_data;
int err;
err = snd_pcm_lib_alloc_vmalloc_buffer(substream,
params_buffer_bytes(hw_params));
if (err < 0)
return err;
if (substream->runtime->status->state == SNDRV_PCM_STATE_OPEN) {
mutex_lock(&ff->mutex);
ff->substreams_counter++;
mutex_unlock(&ff->mutex);
}
return 0;
}
static int pcm_capture_hw_free(struct snd_pcm_substream *substream)
{
struct snd_ff *ff = substream->private_data;
mutex_lock(&ff->mutex);
if (substream->runtime->status->state != SNDRV_PCM_STATE_OPEN)
ff->substreams_counter--;
snd_ff_stream_stop_duplex(ff);
mutex_unlock(&ff->mutex);
return snd_pcm_lib_free_vmalloc_buffer(substream);
}
static int pcm_playback_hw_free(struct snd_pcm_substream *substream)
{
struct snd_ff *ff = substream->private_data;
mutex_lock(&ff->mutex);
if (substream->runtime->status->state != SNDRV_PCM_STATE_OPEN)
ff->substreams_counter--;
snd_ff_stream_stop_duplex(ff);
mutex_unlock(&ff->mutex);
return snd_pcm_lib_free_vmalloc_buffer(substream);
}
static int pcm_capture_prepare(struct snd_pcm_substream *substream)
{
struct snd_ff *ff = substream->private_data;
struct snd_pcm_runtime *runtime = substream->runtime;
int err;
mutex_lock(&ff->mutex);
err = snd_ff_stream_start_duplex(ff, runtime->rate);
if (err >= 0)
amdtp_stream_pcm_prepare(&ff->tx_stream);
mutex_unlock(&ff->mutex);
return err;
}
static int pcm_playback_prepare(struct snd_pcm_substream *substream)
{
struct snd_ff *ff = substream->private_data;
struct snd_pcm_runtime *runtime = substream->runtime;
int err;
mutex_lock(&ff->mutex);
err = snd_ff_stream_start_duplex(ff, runtime->rate);
if (err >= 0)
amdtp_stream_pcm_prepare(&ff->rx_stream);
mutex_unlock(&ff->mutex);
return err;
}
static int pcm_capture_trigger(struct snd_pcm_substream *substream, int cmd)
{
struct snd_ff *ff = substream->private_data;
switch (cmd) {
case SNDRV_PCM_TRIGGER_START:
amdtp_stream_pcm_trigger(&ff->tx_stream, substream);
break;
case SNDRV_PCM_TRIGGER_STOP:
amdtp_stream_pcm_trigger(&ff->tx_stream, NULL);
break;
default:
return -EINVAL;
}
return 0;
}
static int pcm_playback_trigger(struct snd_pcm_substream *substream, int cmd)
{
struct snd_ff *ff = substream->private_data;
switch (cmd) {
case SNDRV_PCM_TRIGGER_START:
amdtp_stream_pcm_trigger(&ff->rx_stream, substream);
break;
case SNDRV_PCM_TRIGGER_STOP:
amdtp_stream_pcm_trigger(&ff->rx_stream, NULL);
break;
default:
return -EINVAL;
}
return 0;
}
static snd_pcm_uframes_t pcm_capture_pointer(struct snd_pcm_substream *sbstrm)
{
struct snd_ff *ff = sbstrm->private_data;
return amdtp_stream_pcm_pointer(&ff->tx_stream);
}
static snd_pcm_uframes_t pcm_playback_pointer(struct snd_pcm_substream *sbstrm)
{
struct snd_ff *ff = sbstrm->private_data;
return amdtp_stream_pcm_pointer(&ff->rx_stream);
}
2017-06-07 08:38:05 +08:00
static int pcm_capture_ack(struct snd_pcm_substream *substream)
{
struct snd_ff *ff = substream->private_data;
return amdtp_stream_pcm_ack(&ff->tx_stream);
}
static int pcm_playback_ack(struct snd_pcm_substream *substream)
{
struct snd_ff *ff = substream->private_data;
return amdtp_stream_pcm_ack(&ff->rx_stream);
}
ALSA: fireface: add support for PCM functionality This commit adds PCM functionality to transmit/receive PCM frames on isochronous packet streaming. This commit enables userspace applications to start/stop packet streaming via ALSA PCM interface. Sampling rate requested by applications is used as sampling transmission frequency of IEC 61883-1/6packet streaming. As I described in followed commits, units in this series manages sampling clock frequency independently of sampling transmission frequency, and they supports resampling between their packet streaming/data block processing layer and sampling data processing layer. This commit take this driver to utilize these features for usability. When internal clock is selected as source signal of sampling clock, this driver allows user space applications to start PCM substreams at any rate which packet streaming engine supports as sampling transmission frequency. In this case, this driver expects units to perform resampling PCM frames for rx/tx packets when sampling clock frequency and sampling transmission frequency are mismatched. This is for daily use cases. When any external clock is selected as the source signal, this driver gets configured sampling rate from units, then restricts available sampling rate to the rate for PCM applications. This is for studio use cases. Models in this series supports 64.0/128.0 kHz of sampling rate, however these frequencies are not supported by IEC 61883-6 as sampling transmission frequency. Therefore, packet streaming engine of ALSA firewire stack can't handle them. When units are configured to use any external clock as source signal of sampling clock and one of these unsupported rate is configured as rate of the sampling clock, this driver returns EIO to user space applications. Anyway, this driver doesn't voluntarily configure parameters of sampling clock. It's better for users to work with appropriate user space implementations to configure the parameters in advance of usage. Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2017-03-31 21:06:10 +08:00
int snd_ff_create_pcm_devices(struct snd_ff *ff)
{
static const struct snd_pcm_ops pcm_capture_ops = {
.open = pcm_open,
.close = pcm_close,
.ioctl = snd_pcm_lib_ioctl,
.hw_params = pcm_capture_hw_params,
.hw_free = pcm_capture_hw_free,
.prepare = pcm_capture_prepare,
.trigger = pcm_capture_trigger,
.pointer = pcm_capture_pointer,
.ack = pcm_capture_ack,
.page = snd_pcm_lib_get_vmalloc_page,
};
static const struct snd_pcm_ops pcm_playback_ops = {
.open = pcm_open,
.close = pcm_close,
.ioctl = snd_pcm_lib_ioctl,
.hw_params = pcm_playback_hw_params,
.hw_free = pcm_playback_hw_free,
.prepare = pcm_playback_prepare,
.trigger = pcm_playback_trigger,
.pointer = pcm_playback_pointer,
.ack = pcm_playback_ack,
.page = snd_pcm_lib_get_vmalloc_page,
};
ALSA: fireface: add support for PCM functionality This commit adds PCM functionality to transmit/receive PCM frames on isochronous packet streaming. This commit enables userspace applications to start/stop packet streaming via ALSA PCM interface. Sampling rate requested by applications is used as sampling transmission frequency of IEC 61883-1/6packet streaming. As I described in followed commits, units in this series manages sampling clock frequency independently of sampling transmission frequency, and they supports resampling between their packet streaming/data block processing layer and sampling data processing layer. This commit take this driver to utilize these features for usability. When internal clock is selected as source signal of sampling clock, this driver allows user space applications to start PCM substreams at any rate which packet streaming engine supports as sampling transmission frequency. In this case, this driver expects units to perform resampling PCM frames for rx/tx packets when sampling clock frequency and sampling transmission frequency are mismatched. This is for daily use cases. When any external clock is selected as the source signal, this driver gets configured sampling rate from units, then restricts available sampling rate to the rate for PCM applications. This is for studio use cases. Models in this series supports 64.0/128.0 kHz of sampling rate, however these frequencies are not supported by IEC 61883-6 as sampling transmission frequency. Therefore, packet streaming engine of ALSA firewire stack can't handle them. When units are configured to use any external clock as source signal of sampling clock and one of these unsupported rate is configured as rate of the sampling clock, this driver returns EIO to user space applications. Anyway, this driver doesn't voluntarily configure parameters of sampling clock. It's better for users to work with appropriate user space implementations to configure the parameters in advance of usage. Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2017-03-31 21:06:10 +08:00
struct snd_pcm *pcm;
int err;
err = snd_pcm_new(ff->card, ff->card->driver, 0, 1, 1, &pcm);
if (err < 0)
return err;
pcm->private_data = ff;
snprintf(pcm->name, sizeof(pcm->name),
"%s PCM", ff->card->shortname);
snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, &pcm_playback_ops);
snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE, &pcm_capture_ops);
return 0;
}