// SPDX-License-Identifier: GPL-2.0+
/*
* virtio-snd: Virtio sound device
* Copyright (C) 2021 OpenSynergy GmbH
*/
#include <sound/pcm_params.h>
#include "virtio_card.h"
/*
* I/O messages lifetime
* ---------------------
*
* Allocation:
* Messages are initially allocated in the ops->hw_params() after the size and
* number of periods have been successfully negotiated.
*
* Freeing:
* Messages can be safely freed after the queue has been successfully flushed
* (RELEASE command in the ops->sync_stop()) and the ops->hw_free() has been
* called.
*
* When the substream stops, the ops->sync_stop() waits until the device has
* completed all pending messages. This wait can be interrupted either by a
* signal or due to a timeout. In this case, the device can still access
* messages even after calling ops->hw_free(). It can also issue an interrupt,
* and the interrupt handler will also try to access message structures.
*
* Therefore, freeing of already allocated messages occurs:
*
* - in ops->hw_params(), if this operator was called several times in a row,
* or if ops->hw_free() failed to free messages previously;
*
* - in ops->hw_free(), if the queue has been successfully flushed;
*
* - in dev->release().
*/
/* Map for converting ALSA format to VirtIO format. */
struct virtsnd_a2v_format {
snd_pcm_format_t alsa_bit;
unsigned int vio_bit;
};
static const struct virtsnd_a2v_format g_a2v_format_map[] = {
{ SNDRV_PCM_FORMAT_IMA_ADPCM, VIRTIO_SND_PCM_FMT_IMA_ADPCM },
{ SNDRV_PCM_FORMAT_MU_LAW, VIRTIO_SND_PCM_FMT_MU_LAW },
{ SNDRV_PCM_FORMAT_A_LAW, VIRTIO_SND_PCM_FMT_A_LAW },
{ SNDRV_PCM_FORMAT_S8, VIRTIO_SND_PCM_FMT_S8 },
{ SNDRV_PCM_FORMAT_U8, VIRTIO_SND_PCM_FMT_U8 },
{ SNDRV_PCM_FORMAT_S16_LE, VIRTIO_SND_PCM_FMT_S16 },
{ SNDRV_PCM_FORMAT_U16_LE, VIRTIO_SND_PCM_FMT_U16 },
{ SNDRV_PCM_FORMAT_S18_3LE, VIRTIO_SND_PCM_FMT_S18_3 },
{ SNDRV_PCM_FORMAT_U18_3LE, VIRTIO_SND_PCM_FMT_U18_3 },
{ SNDRV_PCM_FORMAT_S20_3LE, VIRTIO_SND_PCM_FMT_S20_3 },
{ SNDRV_PCM_FORMAT_U20_3LE, VIRTIO_SND_PCM_FMT_U20_3 },
{ SNDRV_PCM_FORMAT_S24_3LE, VIRTIO_SND_PCM_FMT_S24_3 },
{ SNDRV_PCM_FORMAT_U24_3LE, VIRTIO_SND_PCM_FMT_U24_3 },
{ SNDRV_PCM_FORMAT_S20_LE, VIRTIO_SND_PCM_FMT_S20 },
{ SNDRV_PCM_FORMAT_U20_LE, VIRTIO_SND_PCM_FMT_U20 },
{ SNDRV_PCM_FORMAT_S24_LE, VIRTIO_SND_PCM_FMT_S24 },
{ SNDRV_PCM_FORMAT_U24_LE, VIRTIO_SND_PCM_FMT_U24 },
{ SNDRV_PCM_FORMAT_S32_LE, VIRTIO_SND_PCM_FMT_S32 },
{ SNDRV_PCM_FORMAT_U32_LE, VIRTIO_SND_PCM_FMT_U32 },
{ SNDRV_PCM_FORMAT_FLOAT_LE, VIRTIO_SND_PCM_FMT_FLOAT },
{ SNDRV_PCM_FORMAT_FLOAT64_LE, VIRTIO_SND_PCM_FMT_FLOAT64 },
{ SNDRV_PCM_FORMAT_DSD_U8, VIRTIO_SND_PCM_FMT_DSD_U8 },
{ SNDRV_PCM_FORMAT_DSD_U16_LE, VIRTIO_SND_PCM_FMT_DSD_U16 },
{ SNDRV_PCM_FORMAT_DSD_U32_LE, VIRTIO_SND_PCM_FMT_DSD_U32 },
{ SNDRV_PCM_FORMAT_IEC958_SUBFRAME_LE,
VIRTIO_SND_PCM_FMT_IEC958_SUBFRAME }
};
/* Map for converting ALSA frame rate to VirtIO frame rate. */
struct virtsnd_a2v_rate {
unsigned int rate;
unsigned int vio_bit;
};
static const struct virtsnd_a2v_rate g_a2v_rate_map[] = {
{ 5512, VIRTIO_SND_PCM_RATE_5512 },
{ 8000, VIRTIO_SND_PCM_RATE_8000 },
{ 11025, VIRTIO_SND_PCM_RATE_11025 },
{ 16000, VIRTIO_SND_PCM_RATE_16000 },
{ 22050, VIRTIO_SND_PCM_RATE_22050 },
{ 32000, VIRTIO_SND_PCM_RATE_32000 },
{ 44100, VIRTIO_SND_PCM_RATE_44100 },
{ 48000, VIRTIO_SND_PCM_RATE_48000 },
{ 64000, VIRTIO_SND_PCM_RATE_64000 },
{ 88200, VIRTIO_SND_PCM_RATE_88200 },
{ 96000, VIRTIO_SND_PCM_RATE_96000 },
{ 176400, VIRTIO_SND_PCM_RATE_176400 },
{ 192000, VIRTIO_SND_PCM_RATE_192000 }
};
static int virtsnd_pcm_sync_stop(struct snd_pcm_substream *substream);
/**
* virtsnd_pcm_open() - Open the PCM substream.
* @substream: Kernel ALSA substream.
*
* Context: Process context.
* Return: 0 on success, -errno on failure.
*/
static int virtsnd_pcm_open(struct snd_pcm_substream *substream)
{
struct virtio_pcm *vpcm = snd_pcm_substream_chip(substream);
struct virtio_pcm_stream *vs = &vpcm->streams[substream->stream];
struct virtio_pcm_substream *vss = vs->substreams[substream->number];
substream->runtime->hw = vss->hw;
substream->private_data = vss;
snd_pcm_hw_constraint_integer(substream->runtime,
SNDRV_PCM_HW_PARAM_PERIODS);
vss->stopped = !!virtsnd_pcm_msg_pending_num(vss);
vss->suspended = false;
/*
* If the substream has already been used, then the I/O queue may be in
* an invalid state. Just in case, we do a check and try to return the
* queue to its original state, if necessary.
*/
return virtsnd_pcm_sync_stop(substream);
}
/**
* virtsnd_pcm_close() - Close the PCM substream.
* @substream: Kernel ALSA substream.
*
* Context: Process context.
* Return: 0.
*/
static int virtsnd_pcm_close(struct snd_pcm_substream *substream)
{
return 0;
}
/**
* virtsnd_pcm_dev_set_params() - Set the parameters of the PCM substream on
* the device side.
* @vss: VirtIO PCM substream.
* @buffer_bytes: Size of the hardware buffer.
* @period_bytes: Size of the hardware period.
* @channels: Selected number of channels.
* @format: Selected sample format (SNDRV_PCM_FORMAT_XXX).
* @rate: Selected frame rate.
*
* Context: Any context that permits to sleep.
* Return: 0 on success, -errno on failure.
*/
static int virtsnd_pcm_dev_set_params(struct virtio_pcm_substream *vss,
unsigned int buffer_bytes,
unsigned int period_bytes,
unsigned int channels,
snd_pcm_format_t format,
unsigned int rate)
{
struct virtio_snd_msg *msg;
struct virtio_snd_pcm_set_params *request;
unsigned int i;
int vformat = -1;
int vrate = -1;
for (i = 0; i < ARRAY_SIZE(g_a2v_format_map); ++i)
if (g_a2v_format_map[i].alsa_bit == format) {
vformat = g_a2v_format_map[i].vio_bit;
break;
}
for (i = 0; i < ARRAY_SIZE(g_a2v_rate_map); ++i)
if (g_a2v_rate_map[i].rate == rate) {
vrate = g_a2v_rate_map[i].vio_bit;
break;
}
if (vformat == -1 || vrate == -1)
return -EINVAL;
msg = virtsnd_pcm_ctl_msg_alloc(vss, VIRTIO_SND_R_PCM_SET_PARAMS,
GFP_KERNEL);
if (!msg)
return -ENOMEM;
request = virtsnd_ctl_msg_request(msg);
request->buffer_bytes = cpu_to_le32(buffer_bytes);
request->period_bytes = cpu_to_le32(period_bytes);
request->channels = channels;
request->format = vformat;
request->rate = vrate;
if (vss->features & (1U << VIRTIO_SND_PCM_F_MSG_POLLING))
request->features |=
cpu_to_le32(1U << VIRTIO_SND_PCM_F_MSG_POLLING);
if (vss->features & (1U << VIRTIO_SND_PCM_F_EVT_XRUNS))
request->features |=
cpu_to_le32(1U << VIRTIO_SND_PCM_F_EVT_XRUNS);
return virtsnd_ctl_msg_send_sync(vss->snd, msg);
}
/**
* virtsnd_pcm_hw_params() - Set the parameters of the PCM substream.
* @substream: Kernel ALSA substream.
* @hw_params: Hardware parameters.
*
* Context: Process context.
* Return: 0 on success, -errno on failure.
*/
static int virtsnd_pcm_hw_params(struct snd_pcm_substream *substream,
struct snd_pcm_hw_params *hw_params)
{
struct virtio_pcm_substream *vss = snd_pcm_substream_chip(substream);
struct virtio_device *vdev = vss->snd->vdev;
int rc;
if (virtsnd_pcm_msg_pending_num(vss)) {
dev_err(&vdev->dev, "SID %u: invalid I/O queue state\n",
vss->sid);
return -EBADFD;
}
rc = virtsnd_pcm_dev_set_params(vss, params_buffer_bytes(hw_params),
params_period_bytes(hw_params),
params_channels(hw_params),
params_format(hw_params),
params_rate(hw_params));
if (rc)
return rc;
/*
* Free previously allocated messages if ops->hw_params() is called
* several times in a row, or if ops->hw_free() failed to free messages.
*/
virtsnd_pcm_msg_free(vss);
return virtsnd_pcm_msg_alloc(vss, params_periods(hw_params),
params_period_bytes(hw_params));
}
/**
* virtsnd_pcm_hw_free() - Reset the parameters of the PCM substream.
* @substream: Kernel ALSA substream.
*
* Context: Process context.
* Return: 0
*/
static int virtsnd_pcm_hw_free(struct snd_pcm_substream *substream)
{
struct virtio_pcm_substream *vss = snd_pcm_substream_chip(substream);
/* If the queue is flushed, we can safely free the messages here. */
if (!virtsnd_pcm_msg_pending_num(vss))
virtsnd_pcm_msg_free(vss);
return 0;
}
/**
* virtsnd_pcm_prepare() - Prepare the PCM substream.
* @substream: Kernel ALSA substream.
*
* Context: Process context.
* Return: 0 on success, -errno on failure.
*/
static int virtsnd_pcm_prepare(struct snd_pcm_substream *substream)
{
struct virtio_pcm_substream *vss = snd_pcm_substream_chip(substream);
struct virtio_device *vdev = vss->snd->vdev;
struct virtio_snd_msg *msg;
if (!vss->suspended) {
if (virtsnd_pcm_msg_pending_num(vss)) {
dev_err(&vdev->dev, "SID %u: invalid I/O queue state\n",
vss->sid);
return -EBADFD;
}
vss->buffer_bytes = snd_pcm_lib_buffer_bytes(substream);
vss->hw_ptr = 0;
} else {
struct snd_pcm_runtime *runtime = substream->runtime;
unsigned int buffer_bytes = snd_pcm_lib_buffer_bytes(substream);
unsigned int period_bytes = snd_pcm_lib_period_bytes(substream);
int rc;
rc = virtsnd_pcm_dev_set_params(vss, buffer_bytes, period_bytes,
runtime->channels,
runtime->format, runtime->rate);
if (rc)
return rc;
}
vss->xfer_xrun = false;
vss->suspended = false;
vss->msg_count = 0;
memset(&vss->pcm_indirect, 0, sizeof(vss->pcm_indirect));
vss->pcm_indirect.sw_buffer_size =
vss->pcm_indirect.hw_buffer_size =
snd_pcm_lib_buffer_bytes(substream);
msg = virtsnd_pcm_ctl_msg_alloc(vss, VIRTIO_SND_R_PCM_PREPARE,
GFP_KERNEL);
if (!msg)
return -ENOMEM;
return virtsnd_ctl_msg_send_sync(vss->snd, msg);
}
/**
* virtsnd_pcm_trigger() - Process command for the PCM substream.
* @substream: Kernel ALSA substream.
* @command: Substream command (SNDRV_PCM_TRIGGER_XXX).
*
* Context: Any context. Takes and releases the VirtIO substream spinlock.
* May take and release the tx/rx queue spinlock.
* Return: 0 on success, -errno on failure.
*/
static int virtsnd_pcm_trigger(struct snd_pcm_substream *substream, int command)
{
struct virtio_pcm_substream *vss = snd_pcm_substream_chip(substream);
struct virtio_snd *snd = vss->snd;
struct virtio_snd_queue *queue;
struct virtio_snd_msg *msg;
unsigned long flags;
int rc = 0;
switch (command) {
case SNDRV_PCM_TRIGGER_START:
case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
queue = virtsnd_pcm_queue(vss);
spin_lock_irqsave(&queue->lock, flags);
spin_lock(&vss->lock);
if (vss->direction == SNDRV_PCM_STREAM_CAPTURE)
rc = virtsnd_pcm_msg_send(vss, 0, vss->buffer_bytes);
if (!rc)
vss->xfer_enabled = true;
spin_unlock(&vss->lock);
spin_unlock_irqrestore(&queue->lock, flags);
if (rc)
return rc;
msg = virtsnd_pcm_ctl_msg_alloc(vss, VIRTIO_SND_R_PCM_START,
GFP_KERNEL);
if (!msg) {
spin_lock_irqsave(&vss->lock, flags);
vss->xfer_enabled = false;
spin_unlock_irqrestore(&vss->lock, flags);
return -ENOMEM;
}
return virtsnd_ctl_msg_send_sync(snd, msg);
case SNDRV_PCM_TRIGGER_SUSPEND:
vss->suspended = true;
fallthrough;
case SNDRV_PCM_TRIGGER_STOP:
vss->stopped = true;
fallthrough;
case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
spin_lock_irqsave(&vss->lock, flags);
vss->xfer_enabled = false;
spin_unlock_irqrestore(&vss->lock, flags);
msg = virtsnd_pcm_ctl_msg_alloc(vss, VIRTIO_SND_R_PCM_STOP,
GFP_KERNEL);
if (!msg)
return -ENOMEM;
return virtsnd_ctl_msg_send_sync(snd, msg);
default:
return -EINVAL;
}
}
/**
* virtsnd_pcm_sync_stop() - Synchronous PCM substream stop.
* @substream: Kernel ALSA substream.
*
* The function can be called both from the upper level or from the driver
* itself.
*
* Context: Process context. Takes and releases the VirtIO substream spinlock.
* Return: 0 on success, -errno on failure.
*/
static int virtsnd_pcm_sync_stop(struct snd_pcm_substream *substream)
{
struct virtio_pcm_substream *vss = snd_pcm_substream_chip(substream);
struct virtio_snd *snd = vss->snd;
struct virtio_snd_msg *msg;
unsigned int js = msecs_to_jiffies(virtsnd_msg_timeout_ms);
int rc;
cancel_work_sync(&vss->elapsed_period);
if (!vss->stopped)
return 0;
msg = virtsnd_pcm_ctl_msg_alloc(vss, VIRTIO_SND_R_PCM_RELEASE,
GFP_KERNEL);
if (!msg)
return -ENOMEM;
rc = virtsnd_ctl_msg_send_sync(snd, msg);
if (rc)
return rc;
/*
* The spec states that upon receipt of the RELEASE command "the device
* MUST complete all pending I/O messages for the specified stream ID".
* Thus, we consider the absence of I/O messages in the queue as an
* indication that the substream has been released.
*/
rc = wait_event_interruptible_timeout(vss->msg_empty,
!virtsnd_pcm_msg_pending_num(vss),
js);
if (rc <= 0) {
dev_warn(&snd->vdev->dev, "SID %u: failed to flush I/O queue\n",
vss->sid);
return !rc ? -ETIMEDOUT : rc;
}
vss->stopped = false;
return 0;
}
/**
* virtsnd_pcm_pb_pointer() - Get the current hardware position for the PCM
* substream for playback.
* @substream: Kernel ALSA substream.
*
* Context: Any context.
* Return: Hardware position in frames inside [0 ... buffer_size) range.
*/
static snd_pcm_uframes_t
virtsnd_pcm_pb_pointer(struct snd_pcm_substream *substream)
{
struct virtio_pcm_substream *vss = snd_pcm_substream_chip(substream);
return snd_pcm_indirect_playback_pointer(substream,
&vss->pcm_indirect,
vss->hw_ptr);
}
/**
* virtsnd_pcm_cp_pointer() - Get the current hardware position for the PCM
* substream for capture.
* @substream: Kernel ALSA substream.
*
* Context: Any context.
* Return: Hardware position in frames inside [0 ... buffer_size) range.
*/
static snd_pcm_uframes_t
virtsnd_pcm_cp_pointer(struct snd_pcm_substream *substream)
{
struct virtio_pcm_substream *vss = snd_pcm_substream_chip(substream);
return snd_pcm_indirect_capture_pointer(substream,
&vss->pcm_indirect,
vss->hw_ptr);
}
static void virtsnd_pcm_trans_copy(struct snd_pcm_substream *substream,
struct snd_pcm_indirect *rec, size_t bytes)
{
struct virtio_pcm_substream *vss = snd_pcm_substream_chip(substream);
virtsnd_pcm_msg_send(vss, rec->sw_data, bytes);
}
static int virtsnd_pcm_pb_ack(struct snd_pcm_substream *substream)
{
struct virtio_pcm_substream *vss = snd_pcm_substream_chip(substream);
struct virtio_snd_queue *queue = virtsnd_pcm_queue(vss);
unsigned long flags;
int rc;
spin_lock_irqsave(&queue->lock, flags);
spin_lock(&vss->lock);
rc = snd_pcm_indirect_playback_transfer(substream, &vss->pcm_indirect,
virtsnd_pcm_trans_copy);
spin_unlock(&vss->lock);
spin_unlock_irqrestore(&queue->lock, flags);
return rc;
}
static int virtsnd_pcm_cp_ack(struct snd_pcm_substream *substream)
{
struct virtio_pcm_substream *vss = snd_pcm_substream_chip(substream);
struct virtio_snd_queue *queue = virtsnd_pcm_queue(vss);
unsigned long flags;
int rc;
spin_lock_irqsave(&queue->lock, flags);
spin_lock(&vss->lock);
rc = snd_pcm_indirect_capture_transfer(substream, &vss->pcm_indirect,
virtsnd_pcm_trans_copy);
spin_unlock(&vss->lock);
spin_unlock_irqrestore(&queue->lock, flags);
return rc;
}
/* PCM substream operators map. */
const struct snd_pcm_ops virtsnd_pcm_ops[] = {
{
.open = virtsnd_pcm_open,
.close = virtsnd_pcm_close,
.ioctl = snd_pcm_lib_ioctl,
.hw_params = virtsnd_pcm_hw_params,
.hw_free = virtsnd_pcm_hw_free,
.prepare = virtsnd_pcm_prepare,
.trigger = virtsnd_pcm_trigger,
.sync_stop = virtsnd_pcm_sync_stop,
.pointer = virtsnd_pcm_pb_pointer,
.ack = virtsnd_pcm_pb_ack,
},
{
.open = virtsnd_pcm_open,
.close = virtsnd_pcm_close,
.ioctl = snd_pcm_lib_ioctl,
.hw_params = virtsnd_pcm_hw_params,
.hw_free = virtsnd_pcm_hw_free,
.prepare = virtsnd_pcm_prepare,
.trigger = virtsnd_pcm_trigger,
.sync_stop = virtsnd_pcm_sync_stop,
.pointer = virtsnd_pcm_cp_pointer,
.ack = virtsnd_pcm_cp_ack,
},
};
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