diff options
Diffstat (limited to 'driver/aim-sound')
| -rw-r--r-- | driver/aim-sound/sound.c | 768 |
1 files changed, 768 insertions, 0 deletions
diff --git a/driver/aim-sound/sound.c b/driver/aim-sound/sound.c new file mode 100644 index 0000000..9c64580 --- /dev/null +++ b/driver/aim-sound/sound.c @@ -0,0 +1,768 @@ +/* + * 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 <linux/module.h> +#include <linux/printk.h> +#include <linux/kernel.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 <mostcore.h> + +#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_new(NULL, -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 <christian.gromm@microchip.com>"); +MODULE_DESCRIPTION("Audio Application Interface Module for MostCore"); |