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usb: gadget: f_uac2: split out audio core

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Abstract the peripheral side ALSA sound card code from
the f_uac2 function into a component that can be called
by various functions, so the various flavors can be split
apart and selectively reused.

Visible changes:
 - add uac_params structure to pass audio paramteres for
   g_audio_setup
 - make ALSA sound card's name configurable
 - add [in/out]_ep_maxpsize
 - allocate snd_uac_chip structure during g_audio_setup
 - add u_audio_[start/stop]_[capture/playback] functions

Signed-off-by: Ruslan Bilovol <ruslan.bilovol@gmail.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
This commit is contained in:
Ruslan Bilovol 2017-06-18 16:23:52 +03:00 committed by Felipe Balbi
parent 7158b57a49
commit eb9fecb9e6
6 changed files with 844 additions and 635 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
drivers/usb/gadget/Kconfig
View File

@ -158,6 +158,9 @@ config USB_U_SERIAL
config USB_U_ETHER
tristate
config USB_U_AUDIO
tristate
config USB_F_SERIAL
tristate
@ -381,6 +384,7 @@ config USB_CONFIGFS_F_UAC2
depends on SND
select USB_LIBCOMPOSITE
select SND_PCM
select USB_U_AUDIO
select USB_F_UAC2
help
This Audio function is compatible with USB Audio Class

1
drivers/usb/gadget/function/Makefile
View File

@ -32,6 +32,7 @@ usb_f_mass_storage-y := f_mass_storage.o storage_common.o
obj-$(CONFIG_USB_F_MASS_STORAGE)+= usb_f_mass_storage.o
usb_f_fs-y := f_fs.o
obj-$(CONFIG_USB_F_FS) += usb_f_fs.o
obj-$(CONFIG_USB_U_AUDIO) += u_audio.o
usb_f_uac1-y := f_uac1.o u_uac1.o
obj-$(CONFIG_USB_F_UAC1) += usb_f_uac1.o
usb_f_uac2-y := f_uac2.o

716
drivers/usb/gadget/function/f_uac2.c
View File

@ -15,10 +15,7 @@
#include <linux/usb/audio-v2.h>
#include <linux/module.h>
#include <sound/core.h>
#include <sound/pcm.h>
#include <sound/pcm_params.h>
#include "u_audio.h"
#include "u_uac2.h"
/*
@ -50,455 +47,23 @@
#define UNFLW_CTRL 8
#define OVFLW_CTRL 10
struct uac2_req {
struct uac2_rtd_params *pp; /* parent param */
struct usb_request *req;
struct f_uac2 {
struct g_audio g_audio;
u8 ac_intf, as_in_intf, as_out_intf;
u8 ac_alt, as_in_alt, as_out_alt; /* needed for get_alt() */
};
struct uac2_rtd_params {
struct snd_uac2_chip *uac2; /* 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;
struct uac2_req *ureq;
spinlock_t lock;
};
struct snd_uac2_chip {
struct uac2_rtd_params p_prm;
struct uac2_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;
};
#define BUFF_SIZE_MAX (PAGE_SIZE * 16)
#define PRD_SIZE_MAX PAGE_SIZE
#define MIN_PERIODS 4
static struct snd_pcm_hardware uac2_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,
};
struct audio_dev {
u8 ac_intf, ac_alt;
u8 as_out_intf, as_out_alt;
u8 as_in_intf, as_in_alt;
struct usb_ep *in_ep, *out_ep;
struct usb_function func;
struct usb_gadget *gadget;
/* The ALSA Sound Card it represents on the USB-Client side */
struct snd_uac2_chip uac2;
};
static inline
struct audio_dev *func_to_agdev(struct usb_function *f)
static inline struct f_uac2 *func_to_uac2(struct usb_function *f)
{
return container_of(f, struct audio_dev, func);
return container_of(f, struct f_uac2, g_audio.func);
}
static inline
struct audio_dev *uac2_to_agdev(struct snd_uac2_chip *u)
{
return container_of(u, struct audio_dev, uac2);
}
static inline
struct f_uac2_opts *agdev_to_uac2_opts(struct audio_dev *agdev)
struct f_uac2_opts *g_audio_to_uac2_opts(struct g_audio *agdev)
{
return container_of(agdev->func.fi, struct f_uac2_opts, func_inst);
}
static inline
uint num_channels(uint chanmask)
{
uint num = 0;
while (chanmask) {
num += (chanmask & 1);
chanmask >>= 1;
}
return num;
}
static void
agdev_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 uac2_req *ur = req->context;
struct snd_pcm_substream *substream;
struct uac2_rtd_params *prm = ur->pp;
struct snd_uac2_chip *uac2 = prm->uac2;
/* 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 = uac2->p_pktsize;
uac2->p_residue += uac2->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 (uac2->p_residue / uac2->p_interval >= uac2->p_framesize) {
req->length += uac2->p_framesize;
uac2->p_residue -= uac2->p_framesize *
uac2->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(uac2->card->dev, "%d Error!\n", __LINE__);
if (update_alsa)
snd_pcm_period_elapsed(substream);
return;
}
static int
uac2_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
{
struct snd_uac2_chip *uac2 = snd_pcm_substream_chip(substream);
struct audio_dev *agdev = uac2_to_agdev(uac2);
struct f_uac2_opts *uac2_opts = agdev_to_uac2_opts(agdev);
struct uac2_rtd_params *prm;
unsigned long flags;
int err = 0;
if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
prm = &uac2->p_prm;
else
prm = &uac2->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 * uac2_opts->req_number);
return err;
}
static snd_pcm_uframes_t uac2_pcm_pointer(struct snd_pcm_substream *substream)
{
struct snd_uac2_chip *uac2 = snd_pcm_substream_chip(substream);
struct uac2_rtd_params *prm;
if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
prm = &uac2->p_prm;
else
prm = &uac2->c_prm;
return bytes_to_frames(substream->runtime, prm->hw_ptr);
}
static int uac2_pcm_hw_params(struct snd_pcm_substream *substream,
struct snd_pcm_hw_params *hw_params)
{
struct snd_uac2_chip *uac2 = snd_pcm_substream_chip(substream);
struct uac2_rtd_params *prm;
int err;
if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
prm = &uac2->p_prm;
else
prm = &uac2->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 uac2_pcm_hw_free(struct snd_pcm_substream *substream)
{
struct snd_uac2_chip *uac2 = snd_pcm_substream_chip(substream);
struct uac2_rtd_params *prm;
if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
prm = &uac2->p_prm;
else
prm = &uac2->c_prm;
prm->dma_area = NULL;
prm->dma_bytes = 0;
prm->period_size = 0;
return snd_pcm_lib_free_pages(substream);
}
static int uac2_pcm_open(struct snd_pcm_substream *substream)
{
struct snd_uac2_chip *uac2 = snd_pcm_substream_chip(substream);
struct snd_pcm_runtime *runtime = substream->runtime;
struct audio_dev *audio_dev;
struct f_uac2_opts *opts;
int p_ssize, c_ssize;
int p_srate, c_srate;
int p_chmask, c_chmask;
audio_dev = uac2_to_agdev(uac2);
opts = container_of(audio_dev->func.fi, struct f_uac2_opts, func_inst);
p_ssize = opts->p_ssize;
c_ssize = opts->c_ssize;
p_srate = opts->p_srate;
c_srate = opts->c_srate;
p_chmask = opts->p_chmask;
c_chmask = opts->c_chmask;
uac2->p_residue = 0;
runtime->hw = uac2_pcm_hardware;
if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
spin_lock_init(&uac2->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 * uac2->p_prm.max_psize
/ runtime->hw.periods_min;
} else {
spin_lock_init(&uac2->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 * uac2->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 uac2_pcm_null(struct snd_pcm_substream *substream)
{
return 0;
}
static struct snd_pcm_ops uac2_pcm_ops = {
.open = uac2_pcm_open,
.close = uac2_pcm_null,
.ioctl = snd_pcm_lib_ioctl,
.hw_params = uac2_pcm_hw_params,
.hw_free = uac2_pcm_hw_free,
.trigger = uac2_pcm_trigger,
.pointer = uac2_pcm_pointer,
.prepare = uac2_pcm_null,
};
static int snd_uac2_probe(struct audio_dev *audio_dev)
{
struct snd_uac2_chip *uac2 = &audio_dev->uac2;
struct snd_card *card;
struct snd_pcm *pcm;
struct f_uac2_opts *opts;
int err;
int p_chmask, c_chmask;
opts = container_of(audio_dev->func.fi, struct f_uac2_opts, func_inst);
p_chmask = opts->p_chmask;
c_chmask = opts->c_chmask;
/* Choose any slot, with no id */
err = snd_card_new(&audio_dev->gadget->dev,
-1, NULL, THIS_MODULE, 0, &card);
if (err < 0)
return err;
uac2->card = card;
/*
* Create first PCM device
* Create a substream only for non-zero channel streams
*/
err = snd_pcm_new(uac2->card, "UAC2 PCM", 0,
p_chmask ? 1 : 0, c_chmask ? 1 : 0, &pcm);
if (err < 0)
goto snd_fail;
strcpy(pcm->name, "UAC2 PCM");
pcm->private_data = uac2;
uac2->pcm = pcm;
snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, &uac2_pcm_ops);
snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE, &uac2_pcm_ops);
strcpy(card->driver, "UAC2_Gadget");
strcpy(card->shortname, "UAC2_Gadget");
sprintf(card->longname, "UAC2_Gadget %i", 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);
uac2->pcm = NULL;
uac2->card = NULL;
return err;
}
static int snd_uac2_remove(struct audio_dev *audio_dev)
{
struct snd_card *card = audio_dev->uac2.card;
if (card)
return snd_card_free(card);
return 0;
}
/* --------- USB Function Interface ------------- */
enum {
@ -886,32 +451,6 @@ struct cntrl_range_lay3 {
__u32 dRES;
} __packed;
static inline void
free_ep(struct uac2_rtd_params *prm, struct usb_ep *ep)
{
struct snd_uac2_chip *uac2 = prm->uac2;
struct audio_dev *agdev = uac2_to_agdev(uac2);
struct f_uac2_opts *uac2_opts = agdev_to_uac2_opts(agdev);
int i;
if (!prm->ep_enabled)
return;
prm->ep_enabled = false;
for (i = 0; i < uac2_opts->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(uac2->card->dev,
"%s:%d Error!\n", __func__, __LINE__);
}
static void set_ep_max_packet_size(const struct f_uac2_opts *uac2_opts,
struct usb_endpoint_descriptor *ep_desc,
unsigned int factor, bool is_playback)
@ -938,12 +477,11 @@ static void set_ep_max_packet_size(const struct f_uac2_opts *uac2_opts,
static int
afunc_bind(struct usb_configuration *cfg, struct usb_function *fn)
{
struct audio_dev *agdev = func_to_agdev(fn);
struct snd_uac2_chip *uac2 = &agdev->uac2;
struct f_uac2 *uac2 = func_to_uac2(fn);
struct g_audio *agdev = func_to_g_audio(fn);
struct usb_composite_dev *cdev = cfg->cdev;
struct usb_gadget *gadget = cdev->gadget;
struct device *dev = &gadget->dev;
struct uac2_rtd_params *prm;
struct f_uac2_opts *uac2_opts;
struct usb_string *us;
int ret;
@ -990,8 +528,8 @@ afunc_bind(struct usb_configuration *cfg, struct usb_function *fn)
return ret;
}
std_ac_if_desc.bInterfaceNumber = ret;
agdev->ac_intf = ret;
agdev->ac_alt = 0;
uac2->ac_intf = ret;
uac2->ac_alt = 0;
ret = usb_interface_id(cfg, fn);
if (ret < 0) {
@ -1000,8 +538,8 @@ afunc_bind(struct usb_configuration *cfg, struct usb_function *fn)
}
std_as_out_if0_desc.bInterfaceNumber = ret;
std_as_out_if1_desc.bInterfaceNumber = ret;
agdev->as_out_intf = ret;
agdev->as_out_alt = 0;
uac2->as_out_intf = ret;
uac2->as_out_alt = 0;
ret = usb_interface_id(cfg, fn);
if (ret < 0) {
@ -1010,8 +548,8 @@ afunc_bind(struct usb_configuration *cfg, struct usb_function *fn)
}
std_as_in_if0_desc.bInterfaceNumber = ret;
std_as_in_if1_desc.bInterfaceNumber = ret;
agdev->as_in_intf = ret;
agdev->as_in_alt = 0;
uac2->as_in_intf = ret;
uac2->as_in_alt = 0;
/* Calculate wMaxPacketSize according to audio bandwidth */
set_ep_max_packet_size(uac2_opts, &fs_epin_desc, 1000, true);
@ -1031,8 +569,10 @@ afunc_bind(struct usb_configuration *cfg, struct usb_function *fn)
return ret;
}
uac2->p_prm.uac2 = uac2;
uac2->c_prm.uac2 = uac2;
agdev->in_ep_maxpsize = max(fs_epin_desc.wMaxPacketSize,
hs_epin_desc.wMaxPacketSize);
agdev->out_ep_maxpsize = max(fs_epout_desc.wMaxPacketSize,
hs_epout_desc.wMaxPacketSize);
hs_epout_desc.bEndpointAddress = fs_epout_desc.bEndpointAddress;
hs_epin_desc.bEndpointAddress = fs_epin_desc.bEndpointAddress;
@ -1044,46 +584,18 @@ afunc_bind(struct usb_configuration *cfg, struct usb_function *fn)
agdev->gadget = gadget;
prm = &agdev->uac2.c_prm;
prm->max_psize = hs_epout_desc.wMaxPacketSize;
prm->ureq = kcalloc(uac2_opts->req_number, sizeof(struct uac2_req),
GFP_KERNEL);
if (!prm->ureq) {
ret = -ENOMEM;
goto err_free_descs;
}
prm->rbuf = kcalloc(uac2_opts->req_number, prm->max_psize, GFP_KERNEL);
if (!prm->rbuf) {
prm->max_psize = 0;
ret = -ENOMEM;
goto err_free_descs;
}
prm = &agdev->uac2.p_prm;
prm->max_psize = hs_epin_desc.wMaxPacketSize;
prm->ureq = kcalloc(uac2_opts->req_number, sizeof(struct uac2_req),
GFP_KERNEL);
if (!prm->ureq) {
ret = -ENOMEM;
goto err_free_descs;
}
prm->rbuf = kcalloc(uac2_opts->req_number, prm->max_psize, GFP_KERNEL);
if (!prm->rbuf) {
prm->max_psize = 0;
ret = -ENOMEM;
goto err_no_memory;
}
ret = snd_uac2_probe(agdev);
agdev->params.p_chmask = uac2_opts->p_chmask;
agdev->params.p_srate = uac2_opts->p_srate;
agdev->params.p_ssize = uac2_opts->p_ssize;
agdev->params.c_chmask = uac2_opts->c_chmask;
agdev->params.c_srate = uac2_opts->c_srate;
agdev->params.c_ssize = uac2_opts->c_ssize;
agdev->params.req_number = uac2_opts->req_number;
ret = g_audio_setup(agdev, "UAC2 PCM", "UAC2_Gadget");
if (ret)
goto err_no_memory;
goto err_free_descs;
return 0;
err_no_memory:
kfree(agdev->uac2.p_prm.ureq);
kfree(agdev->uac2.c_prm.ureq);
kfree(agdev->uac2.p_prm.rbuf);
kfree(agdev->uac2.c_prm.rbuf);
err_free_descs:
usb_free_all_descriptors(fn);
agdev->gadget = NULL;
@ -1094,15 +606,10 @@ static int
afunc_set_alt(struct usb_function *fn, unsigned intf, unsigned alt)
{
struct usb_composite_dev *cdev = fn->config->cdev;
struct audio_dev *agdev = func_to_agdev(fn);
struct f_uac2_opts *opts = agdev_to_uac2_opts(agdev);
struct snd_uac2_chip *uac2 = &agdev->uac2;
struct f_uac2 *uac2 = func_to_uac2(fn);
struct usb_gadget *gadget = cdev->gadget;
struct device *dev = &gadget->dev;
struct usb_request *req;
struct usb_ep *ep;
struct uac2_rtd_params *prm;
int req_len, i;
int ret = 0;
/* No i/f has more than 2 alt settings */
if (alt > 1) {
@ -1110,7 +617,7 @@ afunc_set_alt(struct usb_function *fn, unsigned intf, unsigned alt)
return -EINVAL;
}
if (intf == agdev->ac_intf) {
if (intf == uac2->ac_intf) {
/* Control I/f has only 1 AltSetting - 0 */
if (alt) {
dev_err(dev, "%s:%d Error!\n", __func__, __LINE__);
@ -1119,92 +626,40 @@ afunc_set_alt(struct usb_function *fn, unsigned intf, unsigned alt)
return 0;
}
if (intf == agdev->as_out_intf) {
ep = agdev->out_ep;
prm = &uac2->c_prm;
config_ep_by_speed(gadget, fn, ep);
agdev->as_out_alt = alt;
req_len = prm->max_psize;
} else if (intf == agdev->as_in_intf) {
unsigned int factor, rate;
struct usb_endpoint_descriptor *ep_desc;
if (intf == uac2->as_out_intf) {
uac2->as_out_alt = alt;
ep = agdev->in_ep;
prm = &uac2->p_prm;
config_ep_by_speed(gadget, fn, ep);
agdev->as_in_alt = alt;
/* pre-calculate the playback endpoint's interval */
if (gadget->speed == USB_SPEED_FULL) {
ep_desc = &fs_epin_desc;
factor = 1000;
} else {
ep_desc = &hs_epin_desc;
factor = 8000;
}
/* pre-compute some values for iso_complete() */
uac2->p_framesize = opts->p_ssize *
num_channels(opts->p_chmask);
rate = opts->p_srate * uac2->p_framesize;
uac2->p_interval = factor / (1 << (ep_desc->bInterval - 1));
uac2->p_pktsize = min_t(unsigned int, rate / uac2->p_interval,
prm->max_psize);
if (uac2->p_pktsize < prm->max_psize)
uac2->p_pktsize_residue = rate % uac2->p_interval;
if (alt)
ret = u_audio_start_capture(&uac2->g_audio);
else
uac2->p_pktsize_residue = 0;
u_audio_stop_capture(&uac2->g_audio);
} else if (intf == uac2->as_in_intf) {
uac2->as_in_alt = alt;
req_len = uac2->p_pktsize;
uac2->p_residue = 0;
if (alt)
ret = u_audio_start_playback(&uac2->g_audio);
else
u_audio_stop_playback(&uac2->g_audio);
} else {
dev_err(dev, "%s:%d Error!\n", __func__, __LINE__);
return -EINVAL;
}
if (alt == 0) {
free_ep(prm, ep);
return 0;
}
prm->ep_enabled = true;
usb_ep_enable(ep);
for (i = 0; i < opts->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 = agdev_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;
return ret;
}
static int
afunc_get_alt(struct usb_function *fn, unsigned intf)
{
struct audio_dev *agdev = func_to_agdev(fn);
struct f_uac2 *uac2 = func_to_uac2(fn);
struct g_audio *agdev = func_to_g_audio(fn);
if (intf == agdev->ac_intf)
return agdev->ac_alt;
else if (intf == agdev->as_out_intf)
return agdev->as_out_alt;
else if (intf == agdev->as_in_intf)
return agdev->as_in_alt;
if (intf == uac2->ac_intf)
return uac2->ac_alt;
else if (intf == uac2->as_out_intf)
return uac2->as_out_alt;
else if (intf == uac2->as_in_intf)
return uac2->as_in_alt;
else
dev_err(&agdev->gadget->dev,
"%s:%d Invalid Interface %d!\n",
@ -1216,21 +671,19 @@ afunc_get_alt(struct usb_function *fn, unsigned intf)
static void
afunc_disable(struct usb_function *fn)
{
struct audio_dev *agdev = func_to_agdev(fn);
struct snd_uac2_chip *uac2 = &agdev->uac2;
struct f_uac2 *uac2 = func_to_uac2(fn);
free_ep(&uac2->p_prm, agdev->in_ep);
agdev->as_in_alt = 0;
free_ep(&uac2->c_prm, agdev->out_ep);
agdev->as_out_alt = 0;
uac2->as_in_alt = 0;
uac2->as_out_alt = 0;
u_audio_stop_capture(&uac2->g_audio);
u_audio_stop_playback(&uac2->g_audio);
}
static int
in_rq_cur(struct usb_function *fn, const struct usb_ctrlrequest *cr)
{
struct usb_request *req = fn->config->cdev->req;
struct audio_dev *agdev = func_to_agdev(fn);
struct g_audio *agdev = func_to_g_audio(fn);
struct f_uac2_opts *opts;
u16 w_length = le16_to_cpu(cr->wLength);
u16 w_index = le16_to_cpu(cr->wIndex);
@ -1240,7 +693,7 @@ in_rq_cur(struct usb_function *fn, const struct usb_ctrlrequest *cr)
int value = -EOPNOTSUPP;
int p_srate, c_srate;
opts = agdev_to_uac2_opts(agdev);
opts = g_audio_to_uac2_opts(agdev);
p_srate = opts->p_srate;
c_srate = opts->c_srate;
@ -1271,7 +724,7 @@ static int
in_rq_range(struct usb_function *fn, const struct usb_ctrlrequest *cr)
{
struct usb_request *req = fn->config->cdev->req;
struct audio_dev *agdev = func_to_agdev(fn);
struct g_audio *agdev = func_to_g_audio(fn);
struct f_uac2_opts *opts;
u16 w_length = le16_to_cpu(cr->wLength);
u16 w_index = le16_to_cpu(cr->wIndex);
@ -1282,7 +735,7 @@ in_rq_range(struct usb_function *fn, const struct usb_ctrlrequest *cr)
int value = -EOPNOTSUPP;
int p_srate, c_srate;
opts = agdev_to_uac2_opts(agdev);
opts = g_audio_to_uac2_opts(agdev);
p_srate = opts->p_srate;
c_srate = opts->c_srate;
@ -1336,11 +789,12 @@ out_rq_cur(struct usb_function *fn, const struct usb_ctrlrequest *cr)
static int
setup_rq_inf(struct usb_function *fn, const struct usb_ctrlrequest *cr)
{
struct audio_dev *agdev = func_to_agdev(fn);
struct f_uac2 *uac2 = func_to_uac2(fn);
struct g_audio *agdev = func_to_g_audio(fn);
u16 w_index = le16_to_cpu(cr->wIndex);
u8 intf = w_index & 0xff;
if (intf != agdev->ac_intf) {
if (intf != uac2->ac_intf) {
dev_err(&agdev->gadget->dev,
"%s:%d Error!\n", __func__, __LINE__);
return -EOPNOTSUPP;
@ -1358,7 +812,7 @@ static int
afunc_setup(struct usb_function *fn, const struct usb_ctrlrequest *cr)
{
struct usb_composite_dev *cdev = fn->config->cdev;
struct audio_dev *agdev = func_to_agdev(fn);
struct g_audio *agdev = func_to_g_audio(fn);
struct usb_request *req = cdev->req;
u16 w_length = le16_to_cpu(cr->wLength);
int value = -EOPNOTSUPP;
@ -1504,10 +958,10 @@ static struct usb_function_instance *afunc_alloc_inst(void)
static void afunc_free(struct usb_function *f)
{
struct audio_dev *agdev;
struct g_audio *agdev;
struct f_uac2_opts *opts;
agdev = func_to_agdev(f);
agdev = func_to_g_audio(f);
opts = container_of(f->fi, struct f_uac2_opts, func_inst);
kfree(agdev);
mutex_lock(&opts->lock);
@ -1517,17 +971,9 @@ static void afunc_free(struct usb_function *f)
static void afunc_unbind(struct usb_configuration *c, struct usb_function *f)
{
struct audio_dev *agdev = func_to_agdev(f);
struct uac2_rtd_params *prm;
struct g_audio *agdev = func_to_g_audio(f);
snd_uac2_remove(agdev);
prm = &agdev->uac2.p_prm;
kfree(prm->rbuf);
prm = &agdev->uac2.c_prm;
kfree(prm->rbuf);
kfree(prm->ureq);
g_audio_cleanup(agdev);
usb_free_all_descriptors(f);
agdev->gadget = NULL;
@ -1535,11 +981,11 @@ static void afunc_unbind(struct usb_configuration *c, struct usb_function *f)
static struct usb_function *afunc_alloc(struct usb_function_instance *fi)
{
struct audio_dev *agdev;
struct f_uac2 *uac2;
struct f_uac2_opts *opts;
agdev = kzalloc(sizeof(*agdev), GFP_KERNEL);
if (agdev == NULL)
uac2 = kzalloc(sizeof(*uac2), GFP_KERNEL);
if (uac2 == NULL)
return ERR_PTR(-ENOMEM);
opts = container_of(fi, struct f_uac2_opts, func_inst);
@ -1547,16 +993,16 @@ static struct usb_function *afunc_alloc(struct usb_function_instance *fi)
++opts->refcnt;
mutex_unlock(&opts->lock);
agdev->func.name = "uac2_func";
agdev->func.bind = afunc_bind;
agdev->func.unbind = afunc_unbind;
agdev->func.set_alt = afunc_set_alt;
agdev->func.get_alt = afunc_get_alt;
agdev->func.disable = afunc_disable;
agdev->func.setup = afunc_setup;
agdev->func.free_func = afunc_free;
uac2->g_audio.func.name = "uac2_func";
uac2->g_audio.func.bind = afunc_bind;
uac2->g_audio.func.unbind = afunc_unbind;
uac2->g_audio.func.set_alt = afunc_set_alt;
uac2->g_audio.func.get_alt = afunc_get_alt;
uac2->g_audio.func.disable = afunc_disable;
uac2->g_audio.func.setup = afunc_setup;
uac2->g_audio.func.free_func = afunc_free;
return &agdev->func;
return &uac2->g_audio.func;
}
DECLARE_USB_FUNCTION_INIT(uac2, afunc_alloc_inst, afunc_alloc);

662
drivers/usb/gadget/function/u_audio.c Normal file
View File

@ -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");

95
drivers/usb/gadget/function/u_audio.h Normal file
View File

@ -0,0 +1,95 @@
/*
* u_audio.h -- interface to USB gadget "ALSA sound card" utilities
*
* Copyright (C) 2016
* Author: Ruslan Bilovol <ruslan.bilovol@gmail.com>
*
* 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.
*
*/
#ifndef __U_AUDIO_H
#define __U_AUDIO_H
#include <linux/usb/composite.h>
struct uac_params {
/* playback */
int p_chmask; /* channel mask */
int p_srate; /* rate in Hz */
int p_ssize; /* sample size */
/* capture */
int c_chmask; /* channel mask */
int c_srate; /* rate in Hz */
int c_ssize; /* sample size */
int req_number; /* number of preallocated requests */
};
struct g_audio {
struct usb_function func;
struct usb_gadget *gadget;
struct usb_ep *in_ep;
struct usb_ep *out_ep;
/* Max packet size for all in_ep possible speeds */
unsigned int in_ep_maxpsize;
/* Max packet size for all out_ep possible speeds */
unsigned int out_ep_maxpsize;
/* The ALSA Sound Card it represents on the USB-Client side */
struct snd_uac_chip *uac;
struct uac_params params;
};
static inline struct g_audio *func_to_g_audio(struct usb_function *f)
{
return container_of(f, struct g_audio, func);
}
static inline uint num_channels(uint chanmask)
{
uint num = 0;
while (chanmask) {
num += (chanmask & 1);
chanmask >>= 1;
}
return num;
}
/*
* g_audio_setup - initialize one virtual ALSA sound card
* @g_audio: struct with filled params, in_ep_maxpsize, out_ep_maxpsize
* @pcm_name: the id string for a PCM instance of this sound card
* @card_name: name of this soundcard
*
* This sets up the single virtual ALSA sound card that may be exported by a
* gadget driver using this framework.
*
* Context: may sleep
*
* Returns zero on success, or a negative error on failure.
*/
int g_audio_setup(struct g_audio *g_audio, const char *pcm_name,
const char *card_name);
void g_audio_cleanup(struct g_audio *g_audio);
int u_audio_start_capture(struct g_audio *g_audio);
void u_audio_stop_capture(struct g_audio *g_audio);
int u_audio_start_playback(struct g_audio *g_audio);
void u_audio_stop_playback(struct g_audio *g_audio);
#endif /* __U_AUDIO_H */

1
drivers/usb/gadget/legacy/Kconfig
View File

@ -56,6 +56,7 @@ config USB_AUDIO
select SND_PCM
select USB_F_UAC1 if GADGET_UAC1
select USB_F_UAC2 if !GADGET_UAC1
select USB_U_AUDIO if USB_F_UAC2
help
This Gadget Audio driver is compatible with USB Audio Class
specification 2.0. It implements 1 AudioControl interface,