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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
commit | 5d1646d90e1f2cceb9f0828f4b28318cd0ec7744 (patch) | |
tree | a94efe259b9009378be6d90eb30d2b019d95c194 /drivers/usb/gadget/function/u_audio.c | |
parent | Initial commit. (diff) | |
download | linux-5d1646d90e1f2cceb9f0828f4b28318cd0ec7744.tar.xz linux-5d1646d90e1f2cceb9f0828f4b28318cd0ec7744.zip |
Adding upstream version 5.10.209.upstream/5.10.209upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/usb/gadget/function/u_audio.c')
-rw-r--r-- | drivers/usb/gadget/function/u_audio.c | 628 |
1 files changed, 628 insertions, 0 deletions
diff --git a/drivers/usb/gadget/function/u_audio.c b/drivers/usb/gadget/function/u_audio.c new file mode 100644 index 000000000..6c8b8f5b7 --- /dev/null +++ b/drivers/usb/gadget/function/u_audio.c @@ -0,0 +1,628 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * u_audio.c -- interface to USB gadget "ALSA sound card" utilities + * + * Copyright (C) 2016 + * Author: Ruslan Bilovol <ruslan.bilovol@gmail.com> + * + * Sound card implementation was cut-and-pasted with changes + * from f_uac2.c and has: + * Copyright (C) 2011 + * Yadwinder Singh (yadi.brar01@gmail.com) + * Jaswinder Singh (jaswinder.singh@linaro.org) + */ + +#include <linux/module.h> +#include <sound/core.h> +#include <sound/pcm.h> +#include <sound/pcm_params.h> + +#include "u_audio.h" + +#define BUFF_SIZE_MAX (PAGE_SIZE * 16) +#define PRD_SIZE_MAX PAGE_SIZE +#define MIN_PERIODS 4 + +struct uac_req { + struct uac_rtd_params *pp; /* parent param */ + struct usb_request *req; +}; + +/* Runtime data params for one stream */ +struct uac_rtd_params { + struct snd_uac_chip *uac; /* parent chip */ + bool ep_enabled; /* if the ep is enabled */ + + struct snd_pcm_substream *ss; + + /* Ring buffer */ + ssize_t hw_ptr; + + void *rbuf; + + unsigned int max_psize; /* MaxPacketSize of endpoint */ + struct uac_req *ureq; + + spinlock_t lock; +}; + +struct snd_uac_chip { + struct g_audio *audio_dev; + + struct uac_rtd_params p_prm; + struct uac_rtd_params c_prm; + + struct snd_card *card; + struct snd_pcm *pcm; + + /* timekeeping for the playback endpoint */ + unsigned int p_interval; + unsigned int p_residue; + + /* pre-calculated values for playback iso completion */ + unsigned int p_pktsize; + unsigned int p_pktsize_residue; + unsigned int p_framesize; +}; + +static const struct snd_pcm_hardware uac_pcm_hardware = { + .info = SNDRV_PCM_INFO_INTERLEAVED | SNDRV_PCM_INFO_BLOCK_TRANSFER + | SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_MMAP_VALID + | SNDRV_PCM_INFO_PAUSE | SNDRV_PCM_INFO_RESUME, + .rates = SNDRV_PCM_RATE_CONTINUOUS, + .periods_max = BUFF_SIZE_MAX / PRD_SIZE_MAX, + .buffer_bytes_max = BUFF_SIZE_MAX, + .period_bytes_max = PRD_SIZE_MAX, + .periods_min = MIN_PERIODS, +}; + +static void u_audio_iso_complete(struct usb_ep *ep, struct usb_request *req) +{ + unsigned int pending; + unsigned long flags, flags2; + unsigned int hw_ptr; + int status = req->status; + struct uac_req *ur = req->context; + struct snd_pcm_substream *substream; + struct snd_pcm_runtime *runtime; + struct uac_rtd_params *prm = ur->pp; + struct snd_uac_chip *uac = prm->uac; + + /* i/f shutting down */ + if (!prm->ep_enabled) { + usb_ep_free_request(ep, req); + return; + } + + if (req->status == -ESHUTDOWN) + return; + + /* + * We can't really do much about bad xfers. + * Afterall, the ISOCH xfers could fail legitimately. + */ + if (status) + pr_debug("%s: iso_complete status(%d) %d/%d\n", + __func__, status, req->actual, req->length); + + substream = prm->ss; + + /* Do nothing if ALSA isn't active */ + if (!substream) + goto exit; + + snd_pcm_stream_lock_irqsave(substream, flags2); + + runtime = substream->runtime; + if (!runtime || !snd_pcm_running(substream)) { + snd_pcm_stream_unlock_irqrestore(substream, flags2); + goto exit; + } + + spin_lock_irqsave(&prm->lock, flags); + + if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) { + /* + * For each IN packet, take the quotient of the current data + * rate and the endpoint's interval as the base packet size. + * If there is a residue from this division, add it to the + * residue accumulator. + */ + req->length = uac->p_pktsize; + uac->p_residue += uac->p_pktsize_residue; + + /* + * Whenever there are more bytes in the accumulator than we + * need to add one more sample frame, increase this packet's + * size and decrease the accumulator. + */ + if (uac->p_residue / uac->p_interval >= uac->p_framesize) { + req->length += uac->p_framesize; + uac->p_residue -= uac->p_framesize * + uac->p_interval; + } + + req->actual = req->length; + } + + hw_ptr = prm->hw_ptr; + + spin_unlock_irqrestore(&prm->lock, flags); + + /* Pack USB load in ALSA ring buffer */ + pending = runtime->dma_bytes - hw_ptr; + + if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) { + if (unlikely(pending < req->actual)) { + memcpy(req->buf, runtime->dma_area + hw_ptr, pending); + memcpy(req->buf + pending, runtime->dma_area, + req->actual - pending); + } else { + memcpy(req->buf, runtime->dma_area + hw_ptr, + req->actual); + } + } else { + if (unlikely(pending < req->actual)) { + memcpy(runtime->dma_area + hw_ptr, req->buf, pending); + memcpy(runtime->dma_area, req->buf + pending, + req->actual - pending); + } else { + memcpy(runtime->dma_area + hw_ptr, req->buf, + req->actual); + } + } + + spin_lock_irqsave(&prm->lock, flags); + /* update hw_ptr after data is copied to memory */ + prm->hw_ptr = (hw_ptr + req->actual) % runtime->dma_bytes; + hw_ptr = prm->hw_ptr; + spin_unlock_irqrestore(&prm->lock, flags); + snd_pcm_stream_unlock_irqrestore(substream, flags2); + + if ((hw_ptr % snd_pcm_lib_period_bytes(substream)) < req->actual) + snd_pcm_period_elapsed(substream); + +exit: + if (usb_ep_queue(ep, req, GFP_ATOMIC)) + dev_err(uac->card->dev, "%d Error!\n", __LINE__); +} + +static int uac_pcm_trigger(struct snd_pcm_substream *substream, int cmd) +{ + struct snd_uac_chip *uac = snd_pcm_substream_chip(substream); + struct uac_rtd_params *prm; + struct g_audio *audio_dev; + struct uac_params *params; + unsigned long flags; + int err = 0; + + audio_dev = uac->audio_dev; + params = &audio_dev->params; + + if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) + prm = &uac->p_prm; + else + prm = &uac->c_prm; + + spin_lock_irqsave(&prm->lock, flags); + + /* Reset */ + prm->hw_ptr = 0; + + switch (cmd) { + case SNDRV_PCM_TRIGGER_START: + case SNDRV_PCM_TRIGGER_RESUME: + prm->ss = substream; + break; + case SNDRV_PCM_TRIGGER_STOP: + case SNDRV_PCM_TRIGGER_SUSPEND: + prm->ss = NULL; + break; + default: + err = -EINVAL; + } + + spin_unlock_irqrestore(&prm->lock, flags); + + /* Clear buffer after Play stops */ + if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK && !prm->ss) + memset(prm->rbuf, 0, prm->max_psize * params->req_number); + + return err; +} + +static snd_pcm_uframes_t uac_pcm_pointer(struct snd_pcm_substream *substream) +{ + struct snd_uac_chip *uac = snd_pcm_substream_chip(substream); + struct uac_rtd_params *prm; + + if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) + prm = &uac->p_prm; + else + prm = &uac->c_prm; + + return bytes_to_frames(substream->runtime, prm->hw_ptr); +} + +static int uac_pcm_open(struct snd_pcm_substream *substream) +{ + struct snd_uac_chip *uac = snd_pcm_substream_chip(substream); + struct snd_pcm_runtime *runtime = substream->runtime; + struct g_audio *audio_dev; + struct uac_params *params; + int p_ssize, c_ssize; + int p_srate, c_srate; + int p_chmask, c_chmask; + + audio_dev = uac->audio_dev; + params = &audio_dev->params; + p_ssize = params->p_ssize; + c_ssize = params->c_ssize; + p_srate = params->p_srate; + c_srate = params->c_srate; + p_chmask = params->p_chmask; + c_chmask = params->c_chmask; + uac->p_residue = 0; + + runtime->hw = uac_pcm_hardware; + + if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) { + spin_lock_init(&uac->p_prm.lock); + runtime->hw.rate_min = p_srate; + switch (p_ssize) { + case 3: + runtime->hw.formats = SNDRV_PCM_FMTBIT_S24_3LE; + break; + case 4: + runtime->hw.formats = SNDRV_PCM_FMTBIT_S32_LE; + break; + default: + runtime->hw.formats = SNDRV_PCM_FMTBIT_S16_LE; + break; + } + runtime->hw.channels_min = num_channels(p_chmask); + runtime->hw.period_bytes_min = 2 * uac->p_prm.max_psize + / runtime->hw.periods_min; + } else { + spin_lock_init(&uac->c_prm.lock); + runtime->hw.rate_min = c_srate; + switch (c_ssize) { + case 3: + runtime->hw.formats = SNDRV_PCM_FMTBIT_S24_3LE; + break; + case 4: + runtime->hw.formats = SNDRV_PCM_FMTBIT_S32_LE; + break; + default: + runtime->hw.formats = SNDRV_PCM_FMTBIT_S16_LE; + break; + } + runtime->hw.channels_min = num_channels(c_chmask); + runtime->hw.period_bytes_min = 2 * uac->c_prm.max_psize + / runtime->hw.periods_min; + } + + runtime->hw.rate_max = runtime->hw.rate_min; + runtime->hw.channels_max = runtime->hw.channels_min; + + snd_pcm_hw_constraint_integer(runtime, SNDRV_PCM_HW_PARAM_PERIODS); + + return 0; +} + +/* ALSA cries without these function pointers */ +static int uac_pcm_null(struct snd_pcm_substream *substream) +{ + return 0; +} + +static const struct snd_pcm_ops uac_pcm_ops = { + .open = uac_pcm_open, + .close = uac_pcm_null, + .trigger = uac_pcm_trigger, + .pointer = uac_pcm_pointer, + .prepare = uac_pcm_null, +}; + +static inline void free_ep(struct uac_rtd_params *prm, struct usb_ep *ep) +{ + struct snd_uac_chip *uac = prm->uac; + struct g_audio *audio_dev; + struct uac_params *params; + int i; + + if (!prm->ep_enabled) + return; + + audio_dev = uac->audio_dev; + params = &audio_dev->params; + + for (i = 0; i < params->req_number; i++) { + if (prm->ureq[i].req) { + if (usb_ep_dequeue(ep, prm->ureq[i].req)) + usb_ep_free_request(ep, prm->ureq[i].req); + /* + * If usb_ep_dequeue() cannot successfully dequeue the + * request, the request will be freed by the completion + * callback. + */ + + prm->ureq[i].req = NULL; + } + } + + prm->ep_enabled = false; + + if (usb_ep_disable(ep)) + dev_err(uac->card->dev, "%s:%d Error!\n", __func__, __LINE__); +} + +int u_audio_start_capture(struct g_audio *audio_dev) +{ + struct snd_uac_chip *uac = audio_dev->uac; + struct usb_gadget *gadget = audio_dev->gadget; + struct device *dev = &gadget->dev; + struct usb_request *req; + struct usb_ep *ep; + struct uac_rtd_params *prm; + struct uac_params *params = &audio_dev->params; + int req_len, i; + + ep = audio_dev->out_ep; + prm = &uac->c_prm; + config_ep_by_speed(gadget, &audio_dev->func, ep); + req_len = ep->maxpacket; + + prm->ep_enabled = true; + usb_ep_enable(ep); + + for (i = 0; i < params->req_number; i++) { + if (!prm->ureq[i].req) { + req = usb_ep_alloc_request(ep, GFP_ATOMIC); + if (req == NULL) + return -ENOMEM; + + prm->ureq[i].req = req; + prm->ureq[i].pp = prm; + + req->zero = 0; + req->context = &prm->ureq[i]; + req->length = req_len; + req->complete = u_audio_iso_complete; + req->buf = prm->rbuf + i * ep->maxpacket; + } + + if (usb_ep_queue(ep, prm->ureq[i].req, GFP_ATOMIC)) + dev_err(dev, "%s:%d Error!\n", __func__, __LINE__); + } + + return 0; +} +EXPORT_SYMBOL_GPL(u_audio_start_capture); + +void u_audio_stop_capture(struct g_audio *audio_dev) +{ + struct snd_uac_chip *uac = audio_dev->uac; + + free_ep(&uac->c_prm, audio_dev->out_ep); +} +EXPORT_SYMBOL_GPL(u_audio_stop_capture); + +int u_audio_start_playback(struct g_audio *audio_dev) +{ + struct snd_uac_chip *uac = audio_dev->uac; + struct usb_gadget *gadget = audio_dev->gadget; + struct device *dev = &gadget->dev; + struct usb_request *req; + struct usb_ep *ep; + struct uac_rtd_params *prm; + struct uac_params *params = &audio_dev->params; + unsigned int factor; + const struct usb_endpoint_descriptor *ep_desc; + int req_len, i; + + ep = audio_dev->in_ep; + prm = &uac->p_prm; + config_ep_by_speed(gadget, &audio_dev->func, ep); + + ep_desc = ep->desc; + + /* pre-calculate the playback endpoint's interval */ + if (gadget->speed == USB_SPEED_FULL) + factor = 1000; + else + factor = 8000; + + /* pre-compute some values for iso_complete() */ + uac->p_framesize = params->p_ssize * + num_channels(params->p_chmask); + uac->p_interval = factor / (1 << (ep_desc->bInterval - 1)); + uac->p_pktsize = min_t(unsigned int, + uac->p_framesize * + (params->p_srate / uac->p_interval), + ep->maxpacket); + + if (uac->p_pktsize < ep->maxpacket) + uac->p_pktsize_residue = uac->p_framesize * + (params->p_srate % uac->p_interval); + else + uac->p_pktsize_residue = 0; + + req_len = uac->p_pktsize; + uac->p_residue = 0; + + prm->ep_enabled = true; + usb_ep_enable(ep); + + for (i = 0; i < params->req_number; i++) { + if (!prm->ureq[i].req) { + req = usb_ep_alloc_request(ep, GFP_ATOMIC); + if (req == NULL) + return -ENOMEM; + + prm->ureq[i].req = req; + prm->ureq[i].pp = prm; + + req->zero = 0; + req->context = &prm->ureq[i]; + req->length = req_len; + req->complete = u_audio_iso_complete; + req->buf = prm->rbuf + i * ep->maxpacket; + } + + if (usb_ep_queue(ep, prm->ureq[i].req, GFP_ATOMIC)) + dev_err(dev, "%s:%d Error!\n", __func__, __LINE__); + } + + return 0; +} +EXPORT_SYMBOL_GPL(u_audio_start_playback); + +void u_audio_stop_playback(struct g_audio *audio_dev) +{ + struct snd_uac_chip *uac = audio_dev->uac; + + free_ep(&uac->p_prm, audio_dev->in_ep); +} +EXPORT_SYMBOL_GPL(u_audio_stop_playback); + +int g_audio_setup(struct g_audio *g_audio, const char *pcm_name, + const char *card_name) +{ + struct snd_uac_chip *uac; + struct snd_card *card; + struct snd_pcm *pcm; + struct uac_params *params; + int p_chmask, c_chmask; + int err; + + if (!g_audio) + return -EINVAL; + + uac = kzalloc(sizeof(*uac), GFP_KERNEL); + if (!uac) + return -ENOMEM; + g_audio->uac = uac; + uac->audio_dev = g_audio; + + params = &g_audio->params; + p_chmask = params->p_chmask; + c_chmask = params->c_chmask; + + if (c_chmask) { + struct uac_rtd_params *prm = &uac->c_prm; + + uac->c_prm.uac = uac; + prm->max_psize = g_audio->out_ep_maxpsize; + + prm->ureq = kcalloc(params->req_number, sizeof(struct uac_req), + GFP_KERNEL); + if (!prm->ureq) { + err = -ENOMEM; + goto fail; + } + + prm->rbuf = kcalloc(params->req_number, prm->max_psize, + GFP_KERNEL); + if (!prm->rbuf) { + prm->max_psize = 0; + err = -ENOMEM; + goto fail; + } + } + + if (p_chmask) { + struct uac_rtd_params *prm = &uac->p_prm; + + uac->p_prm.uac = uac; + prm->max_psize = g_audio->in_ep_maxpsize; + + prm->ureq = kcalloc(params->req_number, sizeof(struct uac_req), + GFP_KERNEL); + if (!prm->ureq) { + err = -ENOMEM; + goto fail; + } + + prm->rbuf = kcalloc(params->req_number, prm->max_psize, + GFP_KERNEL); + if (!prm->rbuf) { + prm->max_psize = 0; + err = -ENOMEM; + goto fail; + } + } + + /* Choose any slot, with no id */ + err = snd_card_new(&g_audio->gadget->dev, + -1, NULL, THIS_MODULE, 0, &card); + if (err < 0) + goto fail; + + uac->card = card; + + /* + * Create first PCM device + * Create a substream only for non-zero channel streams + */ + err = snd_pcm_new(uac->card, pcm_name, 0, + p_chmask ? 1 : 0, c_chmask ? 1 : 0, &pcm); + if (err < 0) + goto snd_fail; + + strlcpy(pcm->name, pcm_name, sizeof(pcm->name)); + pcm->private_data = uac; + uac->pcm = pcm; + + snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, &uac_pcm_ops); + snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE, &uac_pcm_ops); + + strlcpy(card->driver, card_name, sizeof(card->driver)); + strlcpy(card->shortname, card_name, sizeof(card->shortname)); + sprintf(card->longname, "%s %i", card_name, card->dev->id); + + snd_pcm_set_managed_buffer_all(pcm, SNDRV_DMA_TYPE_CONTINUOUS, + NULL, 0, BUFF_SIZE_MAX); + + err = snd_card_register(card); + + if (!err) + return 0; + +snd_fail: + snd_card_free(card); +fail: + kfree(uac->p_prm.ureq); + kfree(uac->c_prm.ureq); + kfree(uac->p_prm.rbuf); + kfree(uac->c_prm.rbuf); + kfree(uac); + + return err; +} +EXPORT_SYMBOL_GPL(g_audio_setup); + +void g_audio_cleanup(struct g_audio *g_audio) +{ + struct snd_uac_chip *uac; + struct snd_card *card; + + if (!g_audio || !g_audio->uac) + return; + + uac = g_audio->uac; + card = uac->card; + if (card) + snd_card_free_when_closed(card); + + kfree(uac->p_prm.ureq); + kfree(uac->c_prm.ureq); + kfree(uac->p_prm.rbuf); + kfree(uac->c_prm.rbuf); + kfree(uac); +} +EXPORT_SYMBOL_GPL(g_audio_cleanup); + +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("USB gadget \"ALSA sound card\" utilities"); +MODULE_AUTHOR("Ruslan Bilovol"); 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