Re: [PATCH v4 2/3] usb: gadget: f_uac2: split out audio core
From: Ruslan Bilovol
Date: Mon May 29 2017 - 19:44:09 EST
On Mon, May 22, 2017 at 6:58 PM, Jassi Brar <jassisinghbrar@xxxxxxxxx> wrote:
> On Thu, May 18, 2017 at 4:07 AM, Ruslan Bilovol
> <ruslan.bilovol@xxxxxxxxx> wrote:
>> 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 | 721 ++++------------------------------
>> drivers/usb/gadget/function/u_audio.c | 661 +++++++++++++++++++++++++++++++
>> drivers/usb/gadget/function/u_audio.h | 95 +++++
>> drivers/usb/gadget/legacy/Kconfig | 1 +
>> 6 files changed, 846 insertions(+), 637 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 c164d6b..2ba0ace 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 d4565b5..059a14a 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 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;
>> +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() */
>> };
>>
>> -#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 @@ 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;
>>
>> agdev->out_ep = usb_ep_autoconfig(gadget, &fs_epout_desc);
>> if (!agdev->out_ep) {
>> @@ -1025,15 +563,17 @@ 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;
>> -
>> /* Calculate wMaxPacketSize according to audio bandwidth */
>> set_ep_max_packet_size(uac2_opts, &fs_epin_desc, 1000, true);
>> set_ep_max_packet_size(uac2_opts, &fs_epout_desc, 1000, false);
>> set_ep_max_packet_size(uac2_opts, &hs_epin_desc, 8000, true);
>> set_ep_max_packet_size(uac2_opts, &hs_epout_desc, 8000, false);
>>
>> + 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);
>> @@ -1547,19 +993,20 @@ 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);
>> MODULE_LICENSE("GPL");
>> MODULE_AUTHOR("Yadwinder Singh");
>> MODULE_AUTHOR("Jaswinder Singh");
>> +MODULE_AUTHOR("Ruslan Bilovol");
>>
> drivers/usb/gadget/function/f_uac2.c | 721 ++++------------------------------
>
> Basically you move out ALSA sound card implementation and %s/agdev/uac2/
> I am not sure churn warrants a MODULE_AUTHOR. People have made far
> more important contribution to the UAC2,
Yes, I added it after cumulative effect of this patch and patch 1/3
where I removed platform driver/device creation from f_uac2.
I haven't find any rules on this and just counted changed lines,
however in this particular case it's better to use something
like MODULE_CLEANER(). Just joking :)
I'll remove this line then.
>
>
>> diff --git a/drivers/usb/gadget/function/u_audio.c b/drivers/usb/gadget/function/u_audio.c
>> new file mode 100644
>> index 0000000..8ee65b8
>> --- /dev/null
>> +++ b/drivers/usb/gadget/function/u_audio.c
>> @@ -0,0 +1,661 @@
>> +/*
>> + * u_audio.c -- interface to USB gadget "ALSA sound card" utilities
>> + *
>> + * Copyright (C) 2016
>> + * Author: Ruslan Bilovol <ruslan.bilovol@xxxxxxxxx>
>> + *
>> + * Based on f_uac2.c which is:
>> + * Copyright (C) 2011
>> + * Yadwinder Singh (yadi.brar01@xxxxxxxxx)
>> + * Jaswinder Singh (jaswinder.singh@xxxxxxxxxx)
>> + *
> Again this is not "based on", rather where you paste the code you cut
> from f_uac2.c
> Of course you also pad it with minor changes to make it useful to your
> uac1 code. I am not happy with losing copyright on the sound card
> implementation for the UAC drivers.
I don't remember why I wrote it as "based on" back in 2016,
probably looking into another patches as example. As per my
understanding, "based on" + your name in Copyright means
that you still continue to hold copyright on the sound card
implementation (otherwise why mention it?).
However I'm not a lawyer so can't say for sure.
Will change this description in next patchset to make it clear,
so you won't loose your copyright.
Best regards
Ruslan
>
>> + * 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
>>