// 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 #include #include #include #include #include #include #include #include #include #include #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 "); MODULE_DESCRIPTION("Sound Component Module for Mostcore");