/* * sound.c - Audio Application Interface Module for Mostcore * * Copyright (C) 2015 Microchip Technology Germany II GmbH & Co. KG * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * This file is licensed under GPLv2. */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include #include #include #include #include #include #include #include #include #include #define DRIVER_NAME "sound" static struct list_head dev_list; static struct most_aim audio_aim; /** * 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); }; #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) #define swap16(val) ( \ (((u16)(val) << 8) & (u16)0xFF00) | \ (((u16)(val) >> 8) & (u16)0x00FF)) #define swap32(val) ( \ (((u32)(val) << 24) & (u32)0xFF000000) | \ (((u32)(val) << 8) & (u32)0x00FF0000) | \ (((u32)(val) >> 8) & (u32)0x0000FF00) | \ (((u32)(val) >> 24) & (u32)0x000000FF)) static void swap_copy16(u16 *dest, const u16 *source, unsigned int bytes) { unsigned int i = 0; while (i < (bytes / 2)) { dest[i] = swap16(source[i]); i++; } } static void swap_copy24(u8 *dest, const u8 *source, unsigned int bytes) { unsigned int i = 0; 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] = swap32(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 channel *channel, *tmp; list_for_each_entry_safe(channel, tmp, &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; int ret; wait_event_interruptible( channel->playback_waitq, kthread_should_stop() || (channel->is_stream_running && (mbo = most_get_mbo(channel->iface, channel->id, &audio_aim)))); if (!mbo) continue; if (channel->is_stream_running) period_elapsed = copy_data(channel, mbo); else memset(mbo->virt_address, 0, mbo->buffer_length); ret = most_submit_mbo(mbo); if (ret) channel->is_stream_running = false; 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; 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); } } if (most_start_channel(channel->iface, channel->id, &audio_aim)) { pr_err("most_start_channel() failed!\n"); if (cfg->direction == MOST_CH_TX) kthread_stop(channel->playback_task); return -EBUSY; } 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, &audio_aim); return 0; } /** * pcm_hw_params - implements hw_params callback function for PCM middle layer * @substream: sub-stream pointer * @hw_params: contains the hardware parameters set by the application * * This is called when the hardware parameters is set by the application, that * is, once when the buffer size, the period size, the format, etc. are defined * for the PCM substream. Many hardware setups should be done is this callback, * including the allocation of buffers. * * Returns 0 on success or error code otherwise. */ static int pcm_hw_params(struct snd_pcm_substream *substream, struct snd_pcm_hw_params *hw_params) { struct channel *channel = substream->private_data; if ((params_channels(hw_params) > channel->pcm_hardware.channels_max) || (params_channels(hw_params) < channel->pcm_hardware.channels_min)) { pr_err("Requested number of channels not supported.\n"); return -EINVAL; } return snd_pcm_lib_alloc_vmalloc_buffer(substream, params_buffer_bytes(hw_params)); } /** * pcm_hw_free - implements hw_free callback function for PCM middle layer * @substream: substream pointer * * This is called to release the resources allocated via hw_params. * This function will be always called before the close callback is called. * * Returns 0 on success or error code otherwise. */ static int pcm_hw_free(struct snd_pcm_substream *substream) { return snd_pcm_lib_free_vmalloc_buffer(substream); } /** * 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) { pr_err("unsupported format\n"); 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: pr_info("pcm_trigger(), invalid\n"); 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 struct snd_pcm_ops pcm_ops = { .open = pcm_open, .close = pcm_close, .ioctl = snd_pcm_lib_ioctl, .hw_params = pcm_hw_params, .hw_free = pcm_hw_free, .prepare = pcm_prepare, .trigger = pcm_trigger, .pointer = pcm_pointer, .page = snd_pcm_lib_get_vmalloc_page, .mmap = snd_pcm_lib_mmap_vmalloc, }; static int split_arg_list(char *buf, char **card_name, char **pcm_format) { *card_name = strsep(&buf, "."); if (!*card_name) return -EIO; *pcm_format = strsep(&buf, ".\n"); if (!*pcm_format) return -EIO; return 0; } static int audio_set_hw_params(struct snd_pcm_hardware *pcm_hw, char *pcm_format, struct most_channel_config *cfg) { 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; if (!strcmp(pcm_format, "1x8")) { if (cfg->subbuffer_size != 1) goto error; pr_info("PCM format is 8-bit mono\n"); pcm_hw->channels_min = 1; pcm_hw->channels_max = 1; pcm_hw->formats = SNDRV_PCM_FMTBIT_S8; } else if (!strcmp(pcm_format, "2x16")) { if (cfg->subbuffer_size != 4) goto error; pr_info("PCM format is 16-bit stereo\n"); pcm_hw->channels_min = 2; pcm_hw->channels_max = 2; pcm_hw->formats = SNDRV_PCM_FMTBIT_S16_LE | SNDRV_PCM_FMTBIT_S16_BE; } else if (!strcmp(pcm_format, "2x24")) { if (cfg->subbuffer_size != 6) goto error; pr_info("PCM format is 24-bit stereo\n"); pcm_hw->channels_min = 2; pcm_hw->channels_max = 2; pcm_hw->formats = SNDRV_PCM_FMTBIT_S24_3LE | SNDRV_PCM_FMTBIT_S24_3BE; } else if (!strcmp(pcm_format, "2x32")) { if (cfg->subbuffer_size != 8) goto error; pr_info("PCM format is 32-bit stereo\n"); pcm_hw->channels_min = 2; pcm_hw->channels_max = 2; pcm_hw->formats = SNDRV_PCM_FMTBIT_S32_LE | SNDRV_PCM_FMTBIT_S32_BE; } else if (!strcmp(pcm_format, "6x16")) { if (cfg->subbuffer_size != 12) goto error; pr_info("PCM format is 16-bit 5.1 multi channel\n"); pcm_hw->channels_min = 6; pcm_hw->channels_max = 6; pcm_hw->formats = SNDRV_PCM_FMTBIT_S16_LE | SNDRV_PCM_FMTBIT_S16_BE; } else { pr_err("PCM format %s not supported\n", pcm_format); return -EIO; } return 0; error: pr_err("Audio resolution doesn't fit subbuffer size\n"); return -EINVAL; } /** * 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 * @parent: pointer to kobject (needed for sysfs hook-up) * @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, struct kobject *parent, char *arg_list) { struct channel *channel; struct snd_card *card; struct snd_pcm *pcm; int playback_count = 0; int capture_count = 0; int ret; int direction; char *card_name; char *pcm_format; if (!iface) return -EINVAL; if (cfg->data_type != MOST_CH_SYNC) { pr_err("Incompatible channel type\n"); return -EINVAL; } if (get_channel(iface, channel_id)) { pr_err("channel (%s:%d) is already linked\n", iface->description, channel_id); return -EINVAL; } if (cfg->direction == MOST_CH_TX) { playback_count = 1; direction = SNDRV_PCM_STREAM_PLAYBACK; } else { capture_count = 1; direction = SNDRV_PCM_STREAM_CAPTURE; } ret = split_arg_list(arg_list, &card_name, &pcm_format); if (ret < 0) { pr_info("PCM format missing\n"); return ret; } ret = snd_card_create(-1, card_name, THIS_MODULE, sizeof(*channel), &card); if (ret < 0) return ret; channel = card->private_data; channel->card = card; channel->cfg = cfg; channel->iface = iface; channel->id = channel_id; init_waitqueue_head(&channel->playback_waitq); if (audio_set_hw_params(&channel->pcm_hardware, pcm_format, cfg)) goto err_free_card; snprintf(card->driver, sizeof(card->driver), "%s", DRIVER_NAME); snprintf(card->shortname, sizeof(card->shortname), "Microchip MOST:%d", card->number); snprintf(card->longname, sizeof(card->longname), "%s at %s, ch %d", card->shortname, iface->description, channel_id); ret = snd_pcm_new(card, card_name, 0, playback_count, capture_count, &pcm); if (ret < 0) goto err_free_card; pcm->private_data = channel; snd_pcm_set_ops(pcm, direction, &pcm_ops); ret = snd_card_register(card); if (ret < 0) goto err_free_card; list_add_tail(&channel->list, &dev_list); return 0; err_free_card: snd_card_free(card); return ret; } /** * 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; channel = get_channel(iface, channel_id); if (!channel) { pr_err("sound_disconnect_channel(), invalid channel %d\n", channel_id); return -EINVAL; } list_del(&channel->list); snd_card_free(channel->card); 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) { pr_err("sound_rx_completion(), invalid channel %d\n", mbo->hdm_channel_id); 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) { pr_err("sound_tx_completion(), invalid channel %d\n", channel_id); return -EINVAL; } wake_up_interruptible(&channel->playback_waitq); return 0; } /** * Initialization of the struct most_aim */ static struct most_aim audio_aim = { .name = DRIVER_NAME, .probe_channel = audio_probe_channel, .disconnect_channel = audio_disconnect_channel, .rx_completion = audio_rx_completion, .tx_completion = audio_tx_completion, }; static int __init audio_init(void) { pr_info("init()\n"); INIT_LIST_HEAD(&dev_list); return most_register_aim(&audio_aim); } static void __exit audio_exit(void) { struct channel *channel, *tmp; pr_info("exit()\n"); list_for_each_entry_safe(channel, tmp, &dev_list, list) { list_del(&channel->list); snd_card_free(channel->card); } most_deregister_aim(&audio_aim); } module_init(audio_init); module_exit(audio_exit); MODULE_LICENSE("GPL"); MODULE_AUTHOR("Christian Gromm "); MODULE_DESCRIPTION("Audio Application Interface Module for MostCore");