[PATCH v5 2/4] usb: gadget: f_uac2: split out audio core

From: Ruslan Bilovol
Date: Sun Jun 18 2017 - 09:24:12 EST

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@xxxxxxxxx>
---
drivers/usb/gadget/Kconfig | 4 +
drivers/usb/gadget/function/Makefile | 1 +
drivers/usb/gadget/function/f_uac2.c | 718 ++++------------------------------
drivers/usb/gadget/function/u_audio.c | 662 +++++++++++++++++++++++++++++++
drivers/usb/gadget/function/u_audio.h | 95 +++++
drivers/usb/gadget/legacy/Kconfig | 1 +
6 files changed, 845 insertions(+), 636 deletions(-)
create mode 100644 drivers/usb/gadget/function/u_audio.c
create mode 100644 drivers/usb/gadget/function/u_audio.h

diff --git a/drivers/usb/gadget/Kconfig b/drivers/usb/gadget/Kconfig
index b3c879b..3b0ffd6 100644
--- a/drivers/usb/gadget/Kconfig
+++ b/drivers/usb/gadget/Kconfig
@@ -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
diff --git a/drivers/usb/gadget/function/Makefile b/drivers/usb/gadget/function/Makefile
index cb8c225..b29f2ae 100644
--- a/drivers/usb/gadget/function/Makefile
+++ b/drivers/usb/gadget/function/Makefile
@@ -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
diff --git a/drivers/usb/gadget/function/f_uac2.c b/drivers/usb/gadget/function/f_uac2.c
index f674bae..9082ce2 100644
--- a/drivers/usb/gadget/function/f_uac2.c
+++ b/drivers/usb/gadget/function/f_uac2.c
@@ -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)
-{
- return container_of(f, struct audio_dev, func);
-}
-
-static inline
-struct audio_dev *uac2_to_agdev(struct snd_uac2_chip *u)
+static inline struct f_uac2 *func_to_uac2(struct usb_function *f)
{
- return container_of(u, struct audio_dev, uac2);
+ return container_of(f, struct f_uac2, g_audio.func);
}

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 @@ static void set_ep_max_packet_size(const struct f_uac2_opts *uac2_opts,
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 @@ static void set_ep_max_packet_size(const struct f_uac2_opts *uac2_opts,
}
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 @@ static void set_ep_max_packet_size(const struct f_uac2_opts *uac2_opts,
}
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 @@ static void set_ep_max_packet_size(const struct f_uac2_opts *uac2_opts,
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 @@ static void set_ep_max_packet_size(const struct f_uac2_opts *uac2_opts,

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 void set_ep_max_packet_size(const struct f_uac2_opts *uac2_opts,
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 @@ static void set_ep_max_packet_size(const struct f_uac2_opts *uac2_opts,
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 @@ static void set_ep_max_packet_size(const struct f_uac2_opts *uac2_opts,
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;
-
- 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 (intf == uac2->as_out_intf) {
+ uac2->as_out_alt = alt;

- 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);
-
- 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;
+ struct f_uac2 *uac2 = func_to_uac2(fn);
+ struct g_audio *agdev = func_to_g_audio(fn);
+
+ 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 @@ static void set_ep_max_packet_size(const struct f_uac2_opts *uac2_opts,
static void
afunc_disable(struct usb_function *fn)
{
- struct audio_dev *agdev = func_to_agdev(fn);
- struct snd_uac2_chip *uac2 = &agdev->uac2;
-
- free_ep(&uac2->p_prm, agdev->in_ep);
- agdev->as_in_alt = 0;
+ struct f_uac2 *uac2 = func_to_uac2(fn);

- 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 @@ static void set_ep_max_packet_size(const struct f_uac2_opts *uac2_opts,
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 void set_ep_max_packet_size(const struct f_uac2_opts *uac2_opts,
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 @@ static void set_ep_max_packet_size(const struct f_uac2_opts *uac2_opts,
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 @@ static void set_ep_max_packet_size(const struct f_uac2_opts *uac2_opts,
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 void set_ep_max_packet_size(const struct f_uac2_opts *uac2_opts,
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;
-
- snd_uac2_remove(agdev);
-
- prm = &agdev->uac2.p_prm;
- kfree(prm->rbuf);
+ struct g_audio *agdev = func_to_g_audio(f);

- 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);
diff --git a/drivers/usb/gadget/function/u_audio.c b/drivers/usb/gadget/function/u_audio.c
new file mode 100644
index 0000000..5dd73b9
--- /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@xxxxxxxxx>
+ *
+ * Sound card implementation was cut-and-pasted with changes
+ * from f_uac2.c and has:
+ * Copyright (C) 2011
+ * Yadwinder Singh (yadi.brar01@xxxxxxxxx)
+ * Jaswinder Singh (jaswinder.singh@xxxxxxxxxx)
+ *
+ * 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");
diff --git a/drivers/usb/gadget/function/u_audio.h b/drivers/usb/gadget/function/u_audio.h
new file mode 100644
index 0000000..07e1378
--- /dev/null
+++ b/drivers/usb/gadget/function/u_audio.h
@@ -0,0 +1,95 @@
+/*
+ * u_audio.h -- interface to USB gadget "ALSA sound card" utilities
+ *
+ * Copyright (C) 2016
+ * Author: Ruslan Bilovol <ruslan.bilovol@xxxxxxxxx>
+ *
+ * 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 */
diff --git a/drivers/usb/gadget/legacy/Kconfig b/drivers/usb/gadget/legacy/Kconfig
index 0b36878..5344064 100644
--- a/drivers/usb/gadget/legacy/Kconfig
+++ b/drivers/usb/gadget/legacy/Kconfig
@@ -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,
--
1.9.1