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path: root/drivers/usb/gadget/function/u_audio.c
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Diffstat (limited to 'drivers/usb/gadget/function/u_audio.c')
-rw-r--r--drivers/usb/gadget/function/u_audio.c662
1 files changed, 662 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 000000000000..5dd73b9e5172
--- /dev/null
+++ b/drivers/usb/gadget/function/u_audio.c
@@ -0,0 +1,662 @@
+/*
+ * 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)
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * 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.
+ */
+
+#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 */
+ /* Size of the ring buffer */
+ size_t dma_bytes;
+ unsigned char *dma_area;
+
+ struct snd_pcm_substream *ss;
+
+ /* Ring buffer */
+ ssize_t hw_ptr;
+
+ void *rbuf;
+
+ size_t period_size;
+
+ unsigned 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 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 pending;
+ unsigned long flags;
+ unsigned int hw_ptr;
+ bool update_alsa = false;
+ int status = req->status;
+ struct uac_req *ur = req->context;
+ struct snd_pcm_substream *substream;
+ struct uac_rtd_params *prm = ur->pp;
+ struct snd_uac_chip *uac = prm->uac;
+
+ /* i/f shutting down */
+ if (!prm->ep_enabled || 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;
+
+ 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;
+ }
+
+ pending = prm->hw_ptr % prm->period_size;
+ pending += req->actual;
+ if (pending >= prm->period_size)
+ update_alsa = true;
+
+ hw_ptr = prm->hw_ptr;
+ prm->hw_ptr = (prm->hw_ptr + req->actual) % prm->dma_bytes;
+
+ spin_unlock_irqrestore(&prm->lock, flags);
+
+ /* Pack USB load in ALSA ring buffer */
+ pending = prm->dma_bytes - hw_ptr;
+
+ if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
+ if (unlikely(pending < req->actual)) {
+ memcpy(req->buf, prm->dma_area + hw_ptr, pending);
+ memcpy(req->buf + pending, prm->dma_area,
+ req->actual - pending);
+ } else {
+ memcpy(req->buf, prm->dma_area + hw_ptr, req->actual);
+ }
+ } else {
+ if (unlikely(pending < req->actual)) {
+ memcpy(prm->dma_area + hw_ptr, req->buf, pending);
+ memcpy(prm->dma_area, req->buf + pending,
+ req->actual - pending);
+ } else {
+ memcpy(prm->dma_area + hw_ptr, req->buf, req->actual);
+ }
+ }
+
+exit:
+ if (usb_ep_queue(ep, req, GFP_ATOMIC))
+ dev_err(uac->card->dev, "%d Error!\n", __LINE__);
+
+ if (update_alsa)
+ snd_pcm_period_elapsed(substream);
+}
+
+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_hw_params(struct snd_pcm_substream *substream,
+ struct snd_pcm_hw_params *hw_params)
+{
+ struct snd_uac_chip *uac = snd_pcm_substream_chip(substream);
+ struct uac_rtd_params *prm;
+ int err;
+
+ if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
+ prm = &uac->p_prm;
+ else
+ prm = &uac->c_prm;
+
+ err = snd_pcm_lib_malloc_pages(substream,
+ params_buffer_bytes(hw_params));
+ if (err >= 0) {
+ prm->dma_bytes = substream->runtime->dma_bytes;
+ prm->dma_area = substream->runtime->dma_area;
+ prm->period_size = params_period_bytes(hw_params);
+ }
+
+ return err;
+}
+
+static int uac_pcm_hw_free(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;
+
+ prm->dma_area = NULL;
+ prm->dma_bytes = 0;
+ prm->period_size = 0;
+
+ return snd_pcm_lib_free_pages(substream);
+}
+
+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 struct snd_pcm_ops uac_pcm_ops = {
+ .open = uac_pcm_open,
+ .close = uac_pcm_null,
+ .ioctl = snd_pcm_lib_ioctl,
+ .hw_params = uac_pcm_hw_params,
+ .hw_free = uac_pcm_hw_free,
+ .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;
+
+ prm->ep_enabled = false;
+
+ audio_dev = uac->audio_dev;
+ params = &audio_dev->params;
+
+ for (i = 0; i < params->req_number; i++) {
+ if (prm->ureq[i].req) {
+ usb_ep_dequeue(ep, prm->ureq[i].req);
+ usb_ep_free_request(ep, prm->ureq[i].req);
+ prm->ureq[i].req = NULL;
+ }
+ }
+
+ 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 = prm->max_psize;
+
+ 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 * prm->max_psize;
+ }
+
+ 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, rate;
+ 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);
+ rate = params->p_srate * uac->p_framesize;
+ uac->p_interval = factor / (1 << (ep_desc->bInterval - 1));
+ uac->p_pktsize = min_t(unsigned int, rate / uac->p_interval,
+ prm->max_psize);
+
+ if (uac->p_pktsize < prm->max_psize)
+ uac->p_pktsize_residue = rate % 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 * prm->max_psize;
+ }
+
+ 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;
+
+ strcpy(pcm->name, 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);
+
+ strcpy(card->driver, card_name);
+ strcpy(card->shortname, card_name);
+ sprintf(card->longname, "%s %i", card_name, card->dev->id);
+
+ snd_pcm_lib_preallocate_pages_for_all(pcm, SNDRV_DMA_TYPE_CONTINUOUS,
+ snd_dma_continuous_data(GFP_KERNEL), 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(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");