diff options
Diffstat (limited to 'drivers/most/most_snd.c')
| -rw-r--r-- | drivers/most/most_snd.c | 745 |
1 files changed, 745 insertions, 0 deletions
diff --git a/drivers/most/most_snd.c b/drivers/most/most_snd.c new file mode 100644 index 000000000000..c87f6a037874 --- /dev/null +++ b/drivers/most/most_snd.c @@ -0,0 +1,745 @@ +// 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 <christian.gromm@microchip.com>"); +MODULE_DESCRIPTION("Sound Component Module for Mostcore"); |