// SPDX-License-Identifier: GPL-2.0
/*
* sound.c - Sound component for Mostcore
*
* Copyright (C) 2015 Microchip Technology Germany II GmbH & Co. KG
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/module.h>
#include <linux/printk.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <sound/core.h>
#include <sound/pcm.h>
#include <sound/pcm_params.h>
#include <linux/sched.h>
#include <linux/kthread.h>
#include <linux/most.h>
#define DRIVER_NAME "sound"
#define STRING_SIZE 80
static struct most_component comp;
/**
* struct channel - private structure to keep channel specific data
* @substream: stores the substream structure
* @pcm_hardware: low-level hardware description
* @iface: interface for which the channel belongs to
* @cfg: channel configuration
* @card: registered sound card
* @list: list for private use
* @id: channel index
* @period_pos: current period position (ring buffer)
* @buffer_pos: current buffer position (ring buffer)
* @is_stream_running: identifies whether a stream is running or not
* @opened: set when the stream is opened
* @playback_task: playback thread
* @playback_waitq: waitq used by playback thread
* @copy_fn: copy function for PCM-specific format and width
*/
struct channel {
struct snd_pcm_substream *substream;
struct snd_pcm_hardware pcm_hardware;
struct most_interface *iface;
struct most_channel_config *cfg;
struct snd_card *card;
struct list_head list;
int id;
unsigned int period_pos;
unsigned int buffer_pos;
bool is_stream_running;
struct task_struct *playback_task;
wait_queue_head_t playback_waitq;
void (*copy_fn)(void *alsa, void *most, unsigned int bytes);
};
struct sound_adapter {
struct list_head dev_list;
struct most_interface *iface;
struct snd_card *card;
struct list_head list;
bool registered;
int pcm_dev_idx;
};
static struct list_head adpt_list;
#define MOST_PCM_INFO (SNDRV_PCM_INFO_MMAP | \
SNDRV_PCM_INFO_MMAP_VALID | \
SNDRV_PCM_INFO_BATCH | \
SNDRV_PCM_INFO_INTERLEAVED | \
SNDRV_PCM_INFO_BLOCK_TRANSFER)
static void swap_copy16(u16 *dest, const u16 *source, unsigned int bytes)
{
unsigned int i = 0;
while (i < (bytes / 2)) {
dest[i] = swab16(source[i]);
i++;
}
}
static void swap_copy24(u8 *dest, const u8 *source, unsigned int bytes)
{
unsigned int i = 0;
if (bytes < 2)
return;
while (i < bytes - 2) {
dest[i] = source[i + 2];
dest[i + 1] = source[i + 1];
dest[i + 2] = source[i];
i += 3;
}
}
static void swap_copy32(u32 *dest, const u32 *source, unsigned int bytes)
{
unsigned int i = 0;
while (i < bytes / 4) {
dest[i] = swab32(source[i]);
i++;
}
}
static void alsa_to_most_memcpy(void *alsa, void *most, unsigned int bytes)
{
memcpy(most, alsa, bytes);
}
static void alsa_to_most_copy16(void *alsa, void *most, unsigned int bytes)
{
swap_copy16(most, alsa, bytes);
}
static void alsa_to_most_copy24(void *alsa, void *most, unsigned int bytes)
{
swap_copy24(most, alsa, bytes);
}
static void alsa_to_most_copy32(void *alsa, void *most, unsigned int bytes)
{
swap_copy32(most, alsa, bytes);
}
static void most_to_alsa_memcpy(void *alsa, void *most, unsigned int bytes)
{
memcpy(alsa, most, bytes);
}
static void most_to_alsa_copy16(void *alsa, void *most, unsigned int bytes)
{
swap_copy16(alsa, most, bytes);
}
static void most_to_alsa_copy24(void *alsa, void *most, unsigned int bytes)
{
swap_copy24(alsa, most, bytes);
}
static void most_to_alsa_copy32(void *alsa, void *most, unsigned int bytes)
{
swap_copy32(alsa, most, bytes);
}
/**
* get_channel - get pointer to channel
* @iface: interface structure
* @channel_id: channel ID
*
* This traverses the channel list and returns the channel matching the
* ID and interface.
*
* Returns pointer to channel on success or NULL otherwise.
*/
static struct channel *get_channel(struct most_interface *iface,
int channel_id)
{
struct sound_adapter *adpt = iface->priv;
struct channel *channel;
list_for_each_entry(channel, &adpt->dev_list, list) {
if ((channel->iface == iface) && (channel->id == channel_id))
return channel;
}
return NULL;
}
/**
* copy_data - implements data copying function
* @channel: channel
* @mbo: MBO from core
*
* Copy data from/to ring buffer to/from MBO and update the buffer position
*/
static bool copy_data(struct channel *channel, struct mbo *mbo)
{
struct snd_pcm_runtime *const runtime = channel->substream->runtime;
unsigned int const frame_bytes = channel->cfg->subbuffer_size;
unsigned int const buffer_size = runtime->buffer_size;
unsigned int frames;
unsigned int fr0;
if (channel->cfg->direction & MOST_CH_RX)
frames = mbo->processed_length / frame_bytes;
else
frames = mbo->buffer_length / frame_bytes;
fr0 = min(buffer_size - channel->buffer_pos, frames);
channel->copy_fn(runtime->dma_area + channel->buffer_pos * frame_bytes,
mbo->virt_address,
fr0 * frame_bytes);
if (frames > fr0) {
/* wrap around at end of ring buffer */
channel->copy_fn(runtime->dma_area,
mbo->virt_address + fr0 * frame_bytes,
(frames - fr0) * frame_bytes);
}
channel->buffer_pos += frames;
if (channel->buffer_pos >= buffer_size)
channel->buffer_pos -= buffer_size;
channel->period_pos += frames;
if (channel->period_pos >= runtime->period_size) {
channel->period_pos -= runtime->period_size;
return true;
}
return false;
}
/**
* playback_thread - function implements the playback thread
* @data: private data
*
* Thread which does the playback functionality in a loop. It waits for a free
* MBO from mostcore for a particular channel and copy the data from ring buffer
* to MBO. Submit the MBO back to mostcore, after copying the data.
*
* Returns 0 on success or error code otherwise.
*/
static int playback_thread(void *data)
{
struct channel *const channel = data;
while (!kthread_should_stop()) {
struct mbo *mbo = NULL;
bool period_elapsed = false;
wait_event_interruptible(
channel->playback_waitq,
kthread_should_stop() ||
(channel->is_stream_running &&
(mbo = most_get_mbo(channel->iface, channel->id,
&comp))));
if (!mbo)
continue;
if (channel->is_stream_running)
period_elapsed = copy_data(channel, mbo);
else
memset(mbo->virt_address, 0, mbo->buffer_length);
most_submit_mbo(mbo);
if (period_elapsed)
snd_pcm_period_elapsed(channel->substream);
}
return 0;
}
/**
* pcm_open - implements open callback function for PCM middle layer
* @substream: pointer to ALSA PCM substream
*
* This is called when a PCM substream is opened. At least, the function should
* initialize the runtime->hw record.
*
* Returns 0 on success or error code otherwise.
*/
static int pcm_open(struct snd_pcm_substream *substream)
{
struct channel *channel = substream->private_data;
struct snd_pcm_runtime *runtime = substream->runtime;
struct most_channel_config *cfg = channel->cfg;
int ret;
channel->substream = substream;
if (cfg->direction == MOST_CH_TX) {
channel->playback_task = kthread_run(playback_thread, channel,
"most_audio_playback");
if (IS_ERR(channel->playback_task)) {
pr_err("Couldn't start thread\n");
return PTR_ERR(channel->playback_task);
}
}
ret = most_start_channel(channel->iface, channel->id, &comp);
if (ret) {
pr_err("most_start_channel() failed!\n");
if (cfg->direction == MOST_CH_TX)
kthread_stop(channel->playback_task);
return ret;
}
runtime->hw = channel->pcm_hardware;
return 0;
}
/**
* pcm_close - implements close callback function for PCM middle layer
* @substream: sub-stream pointer
*
* Obviously, this is called when a PCM substream is closed. Any private
* instance for a PCM substream allocated in the open callback will be
* released here.
*
* Returns 0 on success or error code otherwise.
*/
static int pcm_close(struct snd_pcm_substream *substream)
{
struct channel *channel = substream->private_data;
if (channel->cfg->direction == MOST_CH_TX)
kthread_stop(channel->playback_task);
most_stop_channel(channel->iface, channel->id, &comp);
return 0;
}
/**
* pcm_prepare - implements prepare callback function for PCM middle layer
* @substream: substream pointer
*
* This callback is called when the PCM is "prepared". Format rate, sample rate,
* etc., can be set here. This callback can be called many times at each setup.
*
* Returns 0 on success or error code otherwise.
*/
static int pcm_prepare(struct snd_pcm_substream *substream)
{
struct channel *channel = substream->private_data;
struct snd_pcm_runtime *runtime = substream->runtime;
struct most_channel_config *cfg = channel->cfg;
int width = snd_pcm_format_physical_width(runtime->format);
channel->copy_fn = NULL;
if (cfg->direction == MOST_CH_TX) {
if (snd_pcm_format_big_endian(runtime->format) || width == 8)
channel->copy_fn = alsa_to_most_memcpy;
else if (width == 16)
channel->copy_fn = alsa_to_most_copy16;
else if (width == 24)
channel->copy_fn = alsa_to_most_copy24;
else if (width == 32)
channel->copy_fn = alsa_to_most_copy32;
} else {
if (snd_pcm_format_big_endian(runtime->format) || width == 8)
channel->copy_fn = most_to_alsa_memcpy;
else if (width == 16)
channel->copy_fn = most_to_alsa_copy16;
else if (width == 24)
channel->copy_fn = most_to_alsa_copy24;
else if (width == 32)
channel->copy_fn = most_to_alsa_copy32;
}
if (!channel->copy_fn)
return -EINVAL;
channel->period_pos = 0;
channel->buffer_pos = 0;
return 0;
}
/**
* pcm_trigger - implements trigger callback function for PCM middle layer
* @substream: substream pointer
* @cmd: action to perform
*
* This is called when the PCM is started, stopped or paused. The action will be
* specified in the second argument, SNDRV_PCM_TRIGGER_XXX
*
* Returns 0 on success or error code otherwise.
*/
static int pcm_trigger(struct snd_pcm_substream *substream, int cmd)
{
struct channel *channel = substream->private_data;
switch (cmd) {
case SNDRV_PCM_TRIGGER_START:
channel->is_stream_running = true;
wake_up_interruptible(&channel->playback_waitq);
return 0;
case SNDRV_PCM_TRIGGER_STOP:
channel->is_stream_running = false;
return 0;
default:
return -EINVAL;
}
return 0;
}
/**
* pcm_pointer - implements pointer callback function for PCM middle layer
* @substream: substream pointer
*
* This callback is called when the PCM middle layer inquires the current
* hardware position on the buffer. The position must be returned in frames,
* ranging from 0 to buffer_size-1.
*/
static snd_pcm_uframes_t pcm_pointer(struct snd_pcm_substream *substream)
{
struct channel *channel = substream->private_data;
return channel->buffer_pos;
}
/*
* Initialization of struct snd_pcm_ops
*/
static const struct snd_pcm_ops pcm_ops = {
.open = pcm_open,
.close = pcm_close,
.prepare = pcm_prepare,
.trigger = pcm_trigger,
.pointer = pcm_pointer,
};
static int split_arg_list(char *buf, u16 *ch_num, char **sample_res)
{
char *num;
int ret;
num = strsep(&buf, "x");
if (!num)
goto err;
ret = kstrtou16(num, 0, ch_num);
if (ret)
goto err;
*sample_res = strsep(&buf, ".\n");
if (!*sample_res)
goto err;
return 0;
err:
pr_err("Bad PCM format\n");
return -EINVAL;
}
static const struct sample_resolution_info {
const char *sample_res;
int bytes;
u64 formats;
} sinfo[] = {
{ "8", 1, SNDRV_PCM_FMTBIT_S8 },
{ "16", 2, SNDRV_PCM_FMTBIT_S16_LE | SNDRV_PCM_FMTBIT_S16_BE },
{ "24", 3, SNDRV_PCM_FMTBIT_S24_3LE | SNDRV_PCM_FMTBIT_S24_3BE },
{ "32", 4, SNDRV_PCM_FMTBIT_S32_LE | SNDRV_PCM_FMTBIT_S32_BE },
};
static int audio_set_hw_params(struct snd_pcm_hardware *pcm_hw,
u16 ch_num, char *sample_res,
struct most_channel_config *cfg)
{
int i;
for (i = 0; i < ARRAY_SIZE(sinfo); i++) {
if (!strcmp(sample_res, sinfo[i].sample_res))
goto found;
}
pr_err("Unsupported PCM format\n");
return -EINVAL;
found:
if (!ch_num) {
pr_err("Bad number of channels\n");
return -EINVAL;
}
if (cfg->subbuffer_size != ch_num * sinfo[i].bytes) {
pr_err("Audio resolution doesn't fit subbuffer size\n");
return -EINVAL;
}
pcm_hw->info = MOST_PCM_INFO;
pcm_hw->rates = SNDRV_PCM_RATE_48000;
pcm_hw->rate_min = 48000;
pcm_hw->rate_max = 48000;
pcm_hw->buffer_bytes_max = cfg->num_buffers * cfg->buffer_size;
pcm_hw->period_bytes_min = cfg->buffer_size;
pcm_hw->period_bytes_max = cfg->buffer_size;
pcm_hw->periods_min = 1;
pcm_hw->periods_max = cfg->num_buffers;
pcm_hw->channels_min = ch_num;
pcm_hw->channels_max = ch_num;
pcm_hw->formats = sinfo[i].formats;
return 0;
}
static void release_adapter(struct sound_adapter *adpt)
{
struct channel *channel, *tmp;
list_for_each_entry_safe(channel, tmp, &adpt->dev_list, list) {
list_del(&channel->list);
kfree(channel);
}
if (adpt->card)
snd_card_free(adpt->card);
list_del(&adpt->list);
kfree(adpt);
}
/**
* audio_probe_channel - probe function of the driver module
* @iface: pointer to interface instance
* @channel_id: channel index/ID
* @cfg: pointer to actual channel configuration
* @device_name: name of the device to be created in /dev
* @arg_list: string that provides the desired audio resolution
*
* Creates sound card, pcm device, sets pcm ops and registers sound card.
*
* Returns 0 on success or error code otherwise.
*/
static int audio_probe_channel(struct most_interface *iface, int channel_id,
struct most_channel_config *cfg,
char *device_name, char *arg_list)
{
struct channel *channel;
struct sound_adapter *adpt;
struct snd_pcm *pcm;
int playback_count = 0;
int capture_count = 0;
int ret;
int direction;
u16 ch_num;
char *sample_res;
char arg_list_cpy[STRING_SIZE];
if (cfg->data_type != MOST_CH_SYNC) {
pr_err("Incompatible channel type\n");
return -EINVAL;
}
strscpy(arg_list_cpy, arg_list, STRING_SIZE);
ret = split_arg_list(arg_list_cpy, &ch_num, &sample_res);
if (ret < 0)
return ret;
list_for_each_entry(adpt, &adpt_list, list) {
if (adpt->iface != iface)
continue;
if (adpt->registered)
return -ENOSPC;
adpt->pcm_dev_idx++;
goto skip_adpt_alloc;
}
adpt = kzalloc(sizeof(*adpt), GFP_KERNEL);
if (!adpt)
return -ENOMEM;
adpt->iface = iface;
INIT_LIST_HEAD(&adpt->dev_list);
iface->priv = adpt;
list_add_tail(&adpt->list, &adpt_list);
ret = snd_card_new(iface->driver_dev, -1, "INIC", THIS_MODULE,
sizeof(*channel), &adpt->card);
if (ret < 0)
goto err_free_adpt;
snprintf(adpt->card->driver, sizeof(adpt->card->driver),
"%s", DRIVER_NAME);
snprintf(adpt->card->shortname, sizeof(adpt->card->shortname),
"Microchip INIC");
snprintf(adpt->card->longname, sizeof(adpt->card->longname),
"%s at %s", adpt->card->shortname, iface->description);
skip_adpt_alloc:
if (get_channel(iface, channel_id)) {
pr_err("channel (%s:%d) is already linked\n",
iface->description, channel_id);
return -EEXIST;
}
if (cfg->direction == MOST_CH_TX) {
playback_count = 1;
direction = SNDRV_PCM_STREAM_PLAYBACK;
} else {
capture_count = 1;
direction = SNDRV_PCM_STREAM_CAPTURE;
}
channel = kzalloc(sizeof(*channel), GFP_KERNEL);
if (!channel) {
ret = -ENOMEM;
goto err_free_adpt;
}
channel->card = adpt->card;
channel->cfg = cfg;
channel->iface = iface;
channel->id = channel_id;
init_waitqueue_head(&channel->playback_waitq);
list_add_tail(&channel->list, &adpt->dev_list);
ret = audio_set_hw_params(&channel->pcm_hardware, ch_num, sample_res,
cfg);
if (ret)
goto err_free_adpt;
ret = snd_pcm_new(adpt->card, device_name, adpt->pcm_dev_idx,
playback_count, capture_count, &pcm);
if (ret < 0)
goto err_free_adpt;
pcm->private_data = channel;
strscpy(pcm->name, device_name, sizeof(pcm->name));
snd_pcm_set_ops(pcm, direction, &pcm_ops);
snd_pcm_set_managed_buffer_all(pcm, SNDRV_DMA_TYPE_VMALLOC, NULL, 0, 0);
return 0;
err_free_adpt:
release_adapter(adpt);
return ret;
}
static int audio_create_sound_card(void)
{
int ret;
struct sound_adapter *adpt;
list_for_each_entry(adpt, &adpt_list, list) {
if (!adpt->registered)
goto adpt_alloc;
}
return -ENODEV;
adpt_alloc:
ret = snd_card_register(adpt->card);
if (ret < 0) {
release_adapter(adpt);
return ret;
}
adpt->registered = true;
return 0;
}
/**
* audio_disconnect_channel - function to disconnect a channel
* @iface: pointer to interface instance
* @channel_id: channel index
*
* This frees allocated memory and removes the sound card from ALSA
*
* Returns 0 on success or error code otherwise.
*/
static int audio_disconnect_channel(struct most_interface *iface,
int channel_id)
{
struct channel *channel;
struct sound_adapter *adpt = iface->priv;
channel = get_channel(iface, channel_id);
if (!channel)
return -EINVAL;
list_del(&channel->list);
kfree(channel);
if (list_empty(&adpt->dev_list))
release_adapter(adpt);
return 0;
}
/**
* audio_rx_completion - completion handler for rx channels
* @mbo: pointer to buffer object that has completed
*
* This searches for the channel this MBO belongs to and copy the data from MBO
* to ring buffer
*
* Returns 0 on success or error code otherwise.
*/
static int audio_rx_completion(struct mbo *mbo)
{
struct channel *channel = get_channel(mbo->ifp, mbo->hdm_channel_id);
bool period_elapsed = false;
if (!channel)
return -EINVAL;
if (channel->is_stream_running)
period_elapsed = copy_data(channel, mbo);
most_put_mbo(mbo);
if (period_elapsed)
snd_pcm_period_elapsed(channel->substream);
return 0;
}
/**
* audio_tx_completion - completion handler for tx channels
* @iface: pointer to interface instance
* @channel_id: channel index/ID
*
* This searches the channel that belongs to this combination of interface
* pointer and channel ID and wakes a process sitting in the wait queue of
* this channel.
*
* Returns 0 on success or error code otherwise.
*/
static int audio_tx_completion(struct most_interface *iface, int channel_id)
{
struct channel *channel = get_channel(iface, channel_id);
if (!channel)
return -EINVAL;
wake_up_interruptible(&channel->playback_waitq);
return 0;
}
/*
* Initialization of the struct most_component
*/
static struct most_component comp = {
.mod = THIS_MODULE,
.name = DRIVER_NAME,
.probe_channel = audio_probe_channel,
.disconnect_channel = audio_disconnect_channel,
.rx_completion = audio_rx_completion,
.tx_completion = audio_tx_completion,
.cfg_complete = audio_create_sound_card,
};
static int __init audio_init(void)
{
int ret;
INIT_LIST_HEAD(&adpt_list);
ret = most_register_component(&comp);
if (ret) {
pr_err("Failed to register %s\n", comp.name);
return ret;
}
ret = most_register_configfs_subsys(&comp);
if (ret) {
pr_err("Failed to register %s configfs subsys\n", comp.name);
most_deregister_component(&comp);
}
return ret;
}
static void __exit audio_exit(void)
{
most_deregister_configfs_subsys(&comp);
most_deregister_component(&comp);
}
module_init(audio_init);
module_exit(audio_exit);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Christian Gromm <[email protected]>");
MODULE_DESCRIPTION("Sound Component Module for Mostcore");
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