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- // 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
- * @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
- */
- 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
- * @arg_list: string that provides the name of the device to be created in /dev
- * plus 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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