/* * Gadget Function Driver for USB audio source device * * Copyright (C) 2012 Google, Inc. * * This software is licensed under the terms of the GNU General Public * License version 2, as published by the Free Software Foundation, and * may be copied, distributed, and modified under those terms. * * 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 #include #include #include #include #include #include #include #include #include #include #include #include #include #include #define SAMPLE_RATE 44100 #define FRAMES_PER_MSEC (SAMPLE_RATE / 1000) #define IN_EP_MAX_PACKET_SIZE 256 /* Number of requests to allocate */ #define IN_EP_REQ_COUNT 4 #define AUDIO_AC_INTERFACE 0 #define AUDIO_AS_INTERFACE 1 #define AUDIO_NUM_INTERFACES 2 #define MAX_INST_NAME_LEN 40 /* B.3.1 Standard AC Interface Descriptor */ static struct usb_interface_descriptor ac_interface_desc = { .bLength = USB_DT_INTERFACE_SIZE, .bDescriptorType = USB_DT_INTERFACE, .bNumEndpoints = 0, .bInterfaceClass = USB_CLASS_AUDIO, .bInterfaceSubClass = USB_SUBCLASS_AUDIOCONTROL, }; DECLARE_UAC_AC_HEADER_DESCRIPTOR(2); #define UAC_DT_AC_HEADER_LENGTH UAC_DT_AC_HEADER_SIZE(AUDIO_NUM_INTERFACES) /* 1 input terminal, 1 output terminal and 1 feature unit */ #define UAC_DT_TOTAL_LENGTH (UAC_DT_AC_HEADER_LENGTH \ + UAC_DT_INPUT_TERMINAL_SIZE + UAC_DT_OUTPUT_TERMINAL_SIZE \ + UAC_DT_FEATURE_UNIT_SIZE(0)) /* B.3.2 Class-Specific AC Interface Descriptor */ static struct uac1_ac_header_descriptor_2 ac_header_desc = { .bLength = UAC_DT_AC_HEADER_LENGTH, .bDescriptorType = USB_DT_CS_INTERFACE, .bDescriptorSubtype = UAC_HEADER, .bcdADC = __constant_cpu_to_le16(0x0100), .wTotalLength = __constant_cpu_to_le16(UAC_DT_TOTAL_LENGTH), .bInCollection = AUDIO_NUM_INTERFACES, .baInterfaceNr = { [0] = AUDIO_AC_INTERFACE, [1] = AUDIO_AS_INTERFACE, } }; #define INPUT_TERMINAL_ID 1 static struct uac_input_terminal_descriptor input_terminal_desc = { .bLength = UAC_DT_INPUT_TERMINAL_SIZE, .bDescriptorType = USB_DT_CS_INTERFACE, .bDescriptorSubtype = UAC_INPUT_TERMINAL, .bTerminalID = INPUT_TERMINAL_ID, .wTerminalType = UAC_INPUT_TERMINAL_MICROPHONE, .bAssocTerminal = 0, .wChannelConfig = 0x3, }; DECLARE_UAC_FEATURE_UNIT_DESCRIPTOR(0); #define FEATURE_UNIT_ID 2 static struct uac_feature_unit_descriptor_0 feature_unit_desc = { .bLength = UAC_DT_FEATURE_UNIT_SIZE(0), .bDescriptorType = USB_DT_CS_INTERFACE, .bDescriptorSubtype = UAC_FEATURE_UNIT, .bUnitID = FEATURE_UNIT_ID, .bSourceID = INPUT_TERMINAL_ID, .bControlSize = 2, }; #define OUTPUT_TERMINAL_ID 3 static struct uac1_output_terminal_descriptor output_terminal_desc = { .bLength = UAC_DT_OUTPUT_TERMINAL_SIZE, .bDescriptorType = USB_DT_CS_INTERFACE, .bDescriptorSubtype = UAC_OUTPUT_TERMINAL, .bTerminalID = OUTPUT_TERMINAL_ID, .wTerminalType = UAC_TERMINAL_STREAMING, .bAssocTerminal = FEATURE_UNIT_ID, .bSourceID = FEATURE_UNIT_ID, }; /* B.4.1 Standard AS Interface Descriptor */ static struct usb_interface_descriptor as_interface_alt_0_desc = { .bLength = USB_DT_INTERFACE_SIZE, .bDescriptorType = USB_DT_INTERFACE, .bAlternateSetting = 0, .bNumEndpoints = 0, .bInterfaceClass = USB_CLASS_AUDIO, .bInterfaceSubClass = USB_SUBCLASS_AUDIOSTREAMING, }; static struct usb_interface_descriptor as_interface_alt_1_desc = { .bLength = USB_DT_INTERFACE_SIZE, .bDescriptorType = USB_DT_INTERFACE, .bAlternateSetting = 1, .bNumEndpoints = 1, .bInterfaceClass = USB_CLASS_AUDIO, .bInterfaceSubClass = USB_SUBCLASS_AUDIOSTREAMING, }; /* B.4.2 Class-Specific AS Interface Descriptor */ static struct uac1_as_header_descriptor as_header_desc = { .bLength = UAC_DT_AS_HEADER_SIZE, .bDescriptorType = USB_DT_CS_INTERFACE, .bDescriptorSubtype = UAC_AS_GENERAL, .bTerminalLink = INPUT_TERMINAL_ID, .bDelay = 1, .wFormatTag = UAC_FORMAT_TYPE_I_PCM, }; DECLARE_UAC_FORMAT_TYPE_I_DISCRETE_DESC(1); static struct uac_format_type_i_discrete_descriptor_1 as_type_i_desc = { .bLength = UAC_FORMAT_TYPE_I_DISCRETE_DESC_SIZE(1), .bDescriptorType = USB_DT_CS_INTERFACE, .bDescriptorSubtype = UAC_FORMAT_TYPE, .bFormatType = UAC_FORMAT_TYPE_I, .bSubframeSize = 2, .bBitResolution = 16, .bSamFreqType = 1, }; /* Standard ISO IN Endpoint Descriptor for highspeed */ static struct usb_endpoint_descriptor hs_as_in_ep_desc = { .bLength = USB_DT_ENDPOINT_AUDIO_SIZE, .bDescriptorType = USB_DT_ENDPOINT, .bEndpointAddress = USB_DIR_IN, .bmAttributes = USB_ENDPOINT_SYNC_SYNC | USB_ENDPOINT_XFER_ISOC, .wMaxPacketSize = __constant_cpu_to_le16(IN_EP_MAX_PACKET_SIZE), .bInterval = 4, /* poll 1 per millisecond */ }; /* Standard ISO IN Endpoint Descriptor for highspeed */ static struct usb_endpoint_descriptor fs_as_in_ep_desc = { .bLength = USB_DT_ENDPOINT_AUDIO_SIZE, .bDescriptorType = USB_DT_ENDPOINT, .bEndpointAddress = USB_DIR_IN, .bmAttributes = USB_ENDPOINT_SYNC_SYNC | USB_ENDPOINT_XFER_ISOC, .wMaxPacketSize = __constant_cpu_to_le16(IN_EP_MAX_PACKET_SIZE), .bInterval = 1, /* poll 1 per millisecond */ }; /* Class-specific AS ISO OUT Endpoint Descriptor */ static struct uac_iso_endpoint_descriptor as_iso_in_desc = { .bLength = UAC_ISO_ENDPOINT_DESC_SIZE, .bDescriptorType = USB_DT_CS_ENDPOINT, .bDescriptorSubtype = UAC_EP_GENERAL, .bmAttributes = 1, .bLockDelayUnits = 1, .wLockDelay = __constant_cpu_to_le16(1), }; static struct usb_descriptor_header *hs_audio_desc[] = { (struct usb_descriptor_header *)&ac_interface_desc, (struct usb_descriptor_header *)&ac_header_desc, (struct usb_descriptor_header *)&input_terminal_desc, (struct usb_descriptor_header *)&output_terminal_desc, (struct usb_descriptor_header *)&feature_unit_desc, (struct usb_descriptor_header *)&as_interface_alt_0_desc, (struct usb_descriptor_header *)&as_interface_alt_1_desc, (struct usb_descriptor_header *)&as_header_desc, (struct usb_descriptor_header *)&as_type_i_desc, (struct usb_descriptor_header *)&hs_as_in_ep_desc, (struct usb_descriptor_header *)&as_iso_in_desc, NULL, }; static struct usb_descriptor_header *fs_audio_desc[] = { (struct usb_descriptor_header *)&ac_interface_desc, (struct usb_descriptor_header *)&ac_header_desc, (struct usb_descriptor_header *)&input_terminal_desc, (struct usb_descriptor_header *)&output_terminal_desc, (struct usb_descriptor_header *)&feature_unit_desc, (struct usb_descriptor_header *)&as_interface_alt_0_desc, (struct usb_descriptor_header *)&as_interface_alt_1_desc, (struct usb_descriptor_header *)&as_header_desc, (struct usb_descriptor_header *)&as_type_i_desc, (struct usb_descriptor_header *)&fs_as_in_ep_desc, (struct usb_descriptor_header *)&as_iso_in_desc, NULL, }; static struct snd_pcm_hardware audio_hw_info = { .info = SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_MMAP_VALID | SNDRV_PCM_INFO_BATCH | SNDRV_PCM_INFO_INTERLEAVED | SNDRV_PCM_INFO_BLOCK_TRANSFER, .formats = SNDRV_PCM_FMTBIT_S16_LE, .channels_min = 2, .channels_max = 2, .rate_min = SAMPLE_RATE, .rate_max = SAMPLE_RATE, .buffer_bytes_max = 1024 * 1024, .period_bytes_min = 64, .period_bytes_max = 512 * 1024, .periods_min = 2, .periods_max = 1024, }; /*-------------------------------------------------------------------------*/ struct audio_source_config { int card; int device; }; struct audio_dev { struct usb_function func; struct snd_card *card; struct snd_pcm *pcm; struct snd_pcm_substream *substream; struct list_head idle_reqs; struct usb_ep *in_ep; spinlock_t lock; /* beginning, end and current position in our buffer */ void *buffer_start; void *buffer_end; void *buffer_pos; /* byte size of a "period" */ unsigned int period; /* bytes sent since last call to snd_pcm_period_elapsed */ unsigned int period_offset; /* time we started playing */ ktime_t start_time; /* number of frames sent since start_time */ s64 frames_sent; struct audio_source_config *config; bool audio_ep_enabled; }; static inline struct audio_dev *func_to_audio(struct usb_function *f) { return container_of(f, struct audio_dev, func); } /*-------------------------------------------------------------------------*/ struct audio_source_instance { struct usb_function_instance func_inst; const char *name; struct audio_source_config *config; struct device *audio_device; }; static void audio_source_attr_release(struct config_item *item); static struct configfs_item_operations audio_source_item_ops = { .release = audio_source_attr_release, }; static struct config_item_type audio_source_func_type = { .ct_item_ops = &audio_source_item_ops, .ct_owner = THIS_MODULE, }; static ssize_t audio_source_pcm_show(struct device *dev, struct device_attribute *attr, char *buf); static DEVICE_ATTR(pcm, S_IRUGO, audio_source_pcm_show, NULL); static struct device_attribute *audio_source_function_attributes[] = { &dev_attr_pcm, NULL }; /*--------------------------------------------------------------------------*/ static struct usb_request *audio_request_new(struct usb_ep *ep, int buffer_size) { struct usb_request *req = usb_ep_alloc_request(ep, GFP_KERNEL); if (!req) return NULL; req->buf = kmalloc(buffer_size, GFP_KERNEL); if (!req->buf) { usb_ep_free_request(ep, req); return NULL; } req->length = buffer_size; return req; } static void audio_request_free(struct usb_request *req, struct usb_ep *ep) { if (req) { kfree(req->buf); usb_ep_free_request(ep, req); } } static void audio_req_put(struct audio_dev *audio, struct usb_request *req) { unsigned long flags; spin_lock_irqsave(&audio->lock, flags); list_add_tail(&req->list, &audio->idle_reqs); spin_unlock_irqrestore(&audio->lock, flags); } static struct usb_request *audio_req_get(struct audio_dev *audio) { unsigned long flags; struct usb_request *req; spin_lock_irqsave(&audio->lock, flags); if (list_empty(&audio->idle_reqs)) { req = 0; } else { req = list_first_entry(&audio->idle_reqs, struct usb_request, list); list_del(&req->list); } spin_unlock_irqrestore(&audio->lock, flags); return req; } /* send the appropriate number of packets to match our bitrate */ static void audio_send(struct audio_dev *audio) { struct snd_pcm_runtime *runtime; struct usb_request *req; int length, length1, length2, ret; s64 msecs; s64 frames; ktime_t now; unsigned long flags; spin_lock_irqsave(&audio->lock, flags); /* audio->substream will be null if we have been closed */ if (!audio->substream) { spin_unlock_irqrestore(&audio->lock, flags); return; } /* audio->buffer_pos will be null if we have been stopped */ if (!audio->buffer_pos) { spin_unlock_irqrestore(&audio->lock, flags); return; } runtime = audio->substream->runtime; spin_unlock_irqrestore(&audio->lock, flags); /* compute number of frames to send */ now = ktime_get(); msecs = ktime_to_ns(now) - ktime_to_ns(audio->start_time); do_div(msecs, 1000000); frames = msecs * SAMPLE_RATE; do_div(frames, 1000); /* Readjust our frames_sent if we fall too far behind. * If we get too far behind it is better to drop some frames than * to keep sending data too fast in an attempt to catch up. */ if (frames - audio->frames_sent > 10 * FRAMES_PER_MSEC) audio->frames_sent = frames - FRAMES_PER_MSEC; frames -= audio->frames_sent; /* We need to send something to keep the pipeline going */ if (frames <= 0) frames = FRAMES_PER_MSEC; while (frames > 0) { req = audio_req_get(audio); spin_lock_irqsave(&audio->lock, flags); /* audio->substream will be null if we have been closed */ if (!audio->substream) { spin_unlock_irqrestore(&audio->lock, flags); return; } /* audio->buffer_pos will be null if we have been stopped */ if (!audio->buffer_pos) { spin_unlock_irqrestore(&audio->lock, flags); return; } if (!req) { spin_unlock_irqrestore(&audio->lock, flags); break; } length = frames_to_bytes(runtime, frames); if (length > IN_EP_MAX_PACKET_SIZE) length = IN_EP_MAX_PACKET_SIZE; if (audio->buffer_pos + length > audio->buffer_end) length1 = audio->buffer_end - audio->buffer_pos; else length1 = length; memcpy(req->buf, audio->buffer_pos, length1); if (length1 < length) { /* Wrap around and copy remaining length * at beginning of buffer. */ length2 = length - length1; memcpy(req->buf + length1, audio->buffer_start, length2); audio->buffer_pos = audio->buffer_start + length2; } else { audio->buffer_pos += length1; if (audio->buffer_pos >= audio->buffer_end) audio->buffer_pos = audio->buffer_start; } req->length = length; spin_unlock_irqrestore(&audio->lock, flags); ret = usb_ep_queue(audio->in_ep, req, GFP_ATOMIC); if (ret < 0) { pr_err("usb_ep_queue failed ret: %d\n", ret); audio_req_put(audio, req); break; } frames -= bytes_to_frames(runtime, length); audio->frames_sent += bytes_to_frames(runtime, length); } } static void audio_control_complete(struct usb_ep *ep, struct usb_request *req) { /* nothing to do here */ } static void audio_data_complete(struct usb_ep *ep, struct usb_request *req) { struct audio_dev *audio = req->context; pr_debug("audio_data_complete req->status %d req->actual %d\n", req->status, req->actual); audio_req_put(audio, req); if (!audio->buffer_start || req->status) return; audio->period_offset += req->actual; if (audio->period_offset >= audio->period) { snd_pcm_period_elapsed(audio->substream); audio->period_offset = 0; } audio_send(audio); } static int audio_set_endpoint_req(struct usb_function *f, const struct usb_ctrlrequest *ctrl) { int value = -EOPNOTSUPP; u16 ep = le16_to_cpu(ctrl->wIndex); u16 len = le16_to_cpu(ctrl->wLength); u16 w_value = le16_to_cpu(ctrl->wValue); pr_debug("bRequest 0x%x, w_value 0x%04x, len %d, endpoint %d\n", ctrl->bRequest, w_value, len, ep); switch (ctrl->bRequest) { case UAC_SET_CUR: case UAC_SET_MIN: case UAC_SET_MAX: case UAC_SET_RES: value = len; break; default: break; } return value; } static int audio_get_endpoint_req(struct usb_function *f, const struct usb_ctrlrequest *ctrl) { struct usb_composite_dev *cdev = f->config->cdev; int value = -EOPNOTSUPP; u8 ep = ((le16_to_cpu(ctrl->wIndex) >> 8) & 0xFF); u16 len = le16_to_cpu(ctrl->wLength); u16 w_value = le16_to_cpu(ctrl->wValue); u8 *buf = cdev->req->buf; pr_debug("bRequest 0x%x, w_value 0x%04x, len %d, endpoint %d\n", ctrl->bRequest, w_value, len, ep); if (w_value == UAC_EP_CS_ATTR_SAMPLE_RATE << 8) { switch (ctrl->bRequest) { case UAC_GET_CUR: case UAC_GET_MIN: case UAC_GET_MAX: case UAC_GET_RES: /* return our sample rate */ buf[0] = (u8)SAMPLE_RATE; buf[1] = (u8)(SAMPLE_RATE >> 8); buf[2] = (u8)(SAMPLE_RATE >> 16); value = 3; break; default: break; } } return value; } static int audio_setup(struct usb_function *f, const struct usb_ctrlrequest *ctrl) { struct usb_composite_dev *cdev = f->config->cdev; struct usb_request *req = cdev->req; int value = -EOPNOTSUPP; u16 w_index = le16_to_cpu(ctrl->wIndex); u16 w_value = le16_to_cpu(ctrl->wValue); u16 w_length = le16_to_cpu(ctrl->wLength); /* composite driver infrastructure handles everything; interface * activation uses set_alt(). */ switch (ctrl->bRequestType) { case USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_ENDPOINT: value = audio_set_endpoint_req(f, ctrl); break; case USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_ENDPOINT: value = audio_get_endpoint_req(f, ctrl); break; } /* respond with data transfer or status phase? */ if (value >= 0) { pr_debug("audio req%02x.%02x v%04x i%04x l%d\n", ctrl->bRequestType, ctrl->bRequest, w_value, w_index, w_length); req->zero = 0; req->length = value; req->complete = audio_control_complete; value = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC); if (value < 0) pr_err("audio response on err %d\n", value); } /* device either stalls (value < 0) or reports success */ return value; } static int audio_set_alt(struct usb_function *f, unsigned intf, unsigned alt) { struct audio_dev *audio = func_to_audio(f); struct usb_composite_dev *cdev = f->config->cdev; int ret; pr_debug("audio_set_alt intf %d, alt %d\n", intf, alt); if (intf == as_interface_alt_1_desc.bInterfaceNumber) { if (alt && !audio->audio_ep_enabled) { ret = config_ep_by_speed(cdev->gadget, f, audio->in_ep); if (ret) { audio->in_ep->desc = NULL; ERROR(cdev, "config_ep fail ep %s, result %d\n", audio->in_ep->name, ret); return ret; } ret = usb_ep_enable(audio->in_ep); if (ret) { ERROR(cdev, "failedto enable ep%s, result %d\n", audio->in_ep->name, ret); return ret; } audio->audio_ep_enabled = true; } else if (!alt && audio->audio_ep_enabled) { usb_ep_disable(audio->in_ep); audio->audio_ep_enabled = false; } } return 0; } static void audio_disable(struct usb_function *f) { struct audio_dev *audio = func_to_audio(f); pr_debug("audio_disable\n"); if (audio->audio_ep_enabled) { usb_ep_disable(audio->in_ep); audio->audio_ep_enabled = false; } } /*-------------------------------------------------------------------------*/ static void audio_build_desc(struct audio_dev *audio) { u8 *sam_freq; int rate; /* Set channel numbers */ input_terminal_desc.bNrChannels = 2; as_type_i_desc.bNrChannels = 2; /* Set sample rates */ rate = SAMPLE_RATE; sam_freq = as_type_i_desc.tSamFreq[0]; memcpy(sam_freq, &rate, 3); } static int snd_card_setup(struct usb_configuration *c, struct audio_source_config *config); static struct audio_source_instance *to_fi_audio_source( const struct usb_function_instance *fi); /* audio function driver setup/binding */ static int audio_bind(struct usb_configuration *c, struct usb_function *f) { struct usb_composite_dev *cdev = c->cdev; struct audio_dev *audio = func_to_audio(f); int status; struct usb_ep *ep; struct usb_request *req; struct audio_source_instance *fi_audio = to_fi_audio_source(f->fi); struct audio_source_config *config = fi_audio->config; int i; int err; err = snd_card_setup(c, config); if (err) { pr_err("snd_card_setup failed with %d\n", err); return err; } audio_build_desc(audio); /* allocate instance-specific interface IDs, and patch descriptors */ status = usb_interface_id(c, f); if (status < 0) goto fail; ac_interface_desc.bInterfaceNumber = status; /* AUDIO_AC_INTERFACE */ ac_header_desc.baInterfaceNr[0] = status; status = usb_interface_id(c, f); if (status < 0) goto fail; as_interface_alt_0_desc.bInterfaceNumber = status; as_interface_alt_1_desc.bInterfaceNumber = status; /* AUDIO_AS_INTERFACE */ ac_header_desc.baInterfaceNr[1] = status; status = -ENODEV; /* allocate our endpoint */ ep = usb_ep_autoconfig(cdev->gadget, &fs_as_in_ep_desc); if (!ep) goto fail; audio->in_ep = ep; ep->driver_data = audio; /* claim */ if (gadget_is_dualspeed(c->cdev->gadget)) hs_as_in_ep_desc.bEndpointAddress = fs_as_in_ep_desc.bEndpointAddress; f->fs_descriptors = fs_audio_desc; f->hs_descriptors = hs_audio_desc; for (i = 0, status = 0; i < IN_EP_REQ_COUNT && status == 0; i++) { req = audio_request_new(ep, IN_EP_MAX_PACKET_SIZE); if (req) { req->context = audio; req->complete = audio_data_complete; audio_req_put(audio, req); } else status = -ENOMEM; } fail: return status; } static void audio_unbind(struct usb_configuration *c, struct usb_function *f) { struct audio_dev *audio = func_to_audio(f); struct usb_request *req; struct audio_source_instance *fi_audio = to_fi_audio_source(f->fi); struct audio_source_config *config = fi_audio->config; while ((req = audio_req_get(audio))) audio_request_free(req, audio->in_ep); snd_card_free_when_closed(audio->card); audio->card = NULL; audio->pcm = NULL; audio->substream = NULL; audio->in_ep = NULL; config->card = -1; config->device = -1; } static void audio_pcm_playback_start(struct audio_dev *audio) { audio->start_time = ktime_get(); audio->frames_sent = 0; audio_send(audio); } static void audio_pcm_playback_stop(struct audio_dev *audio) { unsigned long flags; spin_lock_irqsave(&audio->lock, flags); audio->buffer_start = 0; audio->buffer_end = 0; audio->buffer_pos = 0; spin_unlock_irqrestore(&audio->lock, flags); } static int audio_pcm_open(struct snd_pcm_substream *substream) { struct snd_pcm_runtime *runtime = substream->runtime; struct audio_dev *audio = substream->private_data; runtime->private_data = audio; runtime->hw = audio_hw_info; snd_pcm_limit_hw_rates(runtime); runtime->hw.channels_max = 2; audio->substream = substream; return 0; } static int audio_pcm_close(struct snd_pcm_substream *substream) { struct audio_dev *audio = substream->private_data; unsigned long flags; spin_lock_irqsave(&audio->lock, flags); audio->substream = NULL; spin_unlock_irqrestore(&audio->lock, flags); return 0; } static int audio_pcm_hw_params(struct snd_pcm_substream *substream, struct snd_pcm_hw_params *params) { struct snd_dma_buffer *buf = &substream->dma_buffer; unsigned int channels = params_channels(params); unsigned int rate = params_rate(params); if (rate != SAMPLE_RATE) return -EINVAL; if (channels != 2) return -EINVAL; if (!substream->pcm->card->dev->coherent_dma_mask) substream->pcm->card->dev->coherent_dma_mask = DMA_BIT_MASK(32); buf->dev.type = SNDRV_DMA_TYPE_DEV; buf->dev.dev = substream->pcm->card->dev; buf->private_data = NULL; buf->area = dma_alloc_coherent(substream->pcm->card->dev, params_buffer_bytes(params), &buf->addr, GFP_KERNEL); if (!buf->area) return -ENOMEM; buf->bytes = params_buffer_bytes(params); snd_pcm_set_runtime_buffer(substream, &substream->dma_buffer); return 0; } static int audio_pcm_hw_free(struct snd_pcm_substream *substream) { struct snd_dma_buffer *buf = &substream->dma_buffer; if (buf->area != NULL) dma_free_coherent(substream->pcm->card->dev, buf->bytes, buf->area, buf->addr); buf->area = NULL; return 0; } static int audio_pcm_prepare(struct snd_pcm_substream *substream) { struct snd_pcm_runtime *runtime = substream->runtime; struct audio_dev *audio = runtime->private_data; audio->period = snd_pcm_lib_period_bytes(substream); audio->period_offset = 0; audio->buffer_start = runtime->dma_area; audio->buffer_end = audio->buffer_start + snd_pcm_lib_buffer_bytes(substream); audio->buffer_pos = audio->buffer_start; return 0; } static snd_pcm_uframes_t audio_pcm_pointer(struct snd_pcm_substream *substream) { struct snd_pcm_runtime *runtime = substream->runtime; struct audio_dev *audio = runtime->private_data; ssize_t bytes = audio->buffer_pos - audio->buffer_start; /* return offset of next frame to fill in our buffer */ return bytes_to_frames(runtime, bytes); } static int audio_pcm_playback_trigger(struct snd_pcm_substream *substream, int cmd) { struct audio_dev *audio = substream->runtime->private_data; int ret = 0; switch (cmd) { case SNDRV_PCM_TRIGGER_START: case SNDRV_PCM_TRIGGER_RESUME: audio_pcm_playback_start(audio); break; case SNDRV_PCM_TRIGGER_STOP: case SNDRV_PCM_TRIGGER_SUSPEND: audio_pcm_playback_stop(audio); break; default: ret = -EINVAL; } return ret; } static int audio_pcm_mmap(struct snd_pcm_substream *substream, struct vm_area_struct *vma) { struct snd_pcm_runtime *runtime = substream->runtime; if (runtime->dma_addr && runtime->dma_bytes) { return dma_mmap_coherent(substream->pcm->card->dev, vma, runtime->dma_area, runtime->dma_addr, runtime->dma_bytes); } else { pr_err("Physical address or size of buf is NULL"); return -EINVAL; } } static struct audio_dev _audio_dev = { .func = { .name = "audio_source", .bind = audio_bind, .unbind = audio_unbind, .set_alt = audio_set_alt, .setup = audio_setup, .disable = audio_disable, }, .lock = __SPIN_LOCK_UNLOCKED(_audio_dev.lock), .idle_reqs = LIST_HEAD_INIT(_audio_dev.idle_reqs), }; static struct snd_pcm_ops audio_playback_ops = { .open = audio_pcm_open, .close = audio_pcm_close, .ioctl = snd_pcm_lib_ioctl, .hw_params = audio_pcm_hw_params, .hw_free = audio_pcm_hw_free, .prepare = audio_pcm_prepare, .trigger = audio_pcm_playback_trigger, .pointer = audio_pcm_pointer, .mmap = audio_pcm_mmap, }; static int snd_card_setup(struct usb_configuration *c, struct audio_source_config *config) { struct audio_dev *audio; struct snd_card *card; struct snd_pcm *pcm; int err; audio = &_audio_dev; err = snd_card_new(&c->cdev->gadget->dev, SNDRV_DEFAULT_IDX1, SNDRV_DEFAULT_STR1, THIS_MODULE, 0, &card); if (err) return err; err = snd_pcm_new(card, "USB audio source", 0, 1, 0, &pcm); if (err) goto pcm_fail; pcm->private_data = audio; pcm->info_flags = 0; audio->pcm = pcm; strlcpy(pcm->name, "USB gadget audio", sizeof(pcm->name)); snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, &audio_playback_ops); snd_pcm_lib_preallocate_pages_for_all(pcm, SNDRV_DMA_TYPE_DEV, NULL, 0, 64 * 1024); strlcpy(card->driver, "audio_source", sizeof(card->driver)); strlcpy(card->shortname, card->driver, sizeof(card->shortname)); strlcpy(card->longname, "USB accessory audio source", sizeof(card->longname)); err = snd_card_register(card); if (err) goto register_fail; config->card = pcm->card->number; config->device = pcm->device; audio->card = card; return 0; register_fail: pcm_fail: snd_card_free(audio->card); return err; } static struct audio_source_instance *to_audio_source_instance( struct config_item *item) { return container_of(to_config_group(item), struct audio_source_instance, func_inst.group); } static struct audio_source_instance *to_fi_audio_source( const struct usb_function_instance *fi) { return container_of(fi, struct audio_source_instance, func_inst); } static void audio_source_attr_release(struct config_item *item) { struct audio_source_instance *fi_audio = to_audio_source_instance(item); usb_put_function_instance(&fi_audio->func_inst); } static int audio_source_set_inst_name(struct usb_function_instance *fi, const char *name) { struct audio_source_instance *fi_audio; char *ptr; int name_len; name_len = strlen(name) + 1; if (name_len > MAX_INST_NAME_LEN) return -ENAMETOOLONG; ptr = kstrndup(name, name_len, GFP_KERNEL); if (!ptr) return -ENOMEM; fi_audio = to_fi_audio_source(fi); fi_audio->name = ptr; return 0; } static void audio_source_free_inst(struct usb_function_instance *fi) { struct audio_source_instance *fi_audio; fi_audio = to_fi_audio_source(fi); device_destroy(fi_audio->audio_device->class, fi_audio->audio_device->devt); kfree(fi_audio->name); kfree(fi_audio->config); } static ssize_t audio_source_pcm_show(struct device *dev, struct device_attribute *attr, char *buf) { struct audio_source_instance *fi_audio = dev_get_drvdata(dev); struct audio_source_config *config = fi_audio->config; /* print PCM card and device numbers */ return sprintf(buf, "%d %d\n", config->card, config->device); } struct device *create_function_device(char *name); static struct usb_function_instance *audio_source_alloc_inst(void) { struct audio_source_instance *fi_audio; struct device_attribute **attrs; struct device_attribute *attr; struct device *dev; void *err_ptr; int err = 0; fi_audio = kzalloc(sizeof(*fi_audio), GFP_KERNEL); if (!fi_audio) return ERR_PTR(-ENOMEM); fi_audio->func_inst.set_inst_name = audio_source_set_inst_name; fi_audio->func_inst.free_func_inst = audio_source_free_inst; fi_audio->config = kzalloc(sizeof(struct audio_source_config), GFP_KERNEL); if (!fi_audio->config) { err_ptr = ERR_PTR(-ENOMEM); goto fail_audio; } config_group_init_type_name(&fi_audio->func_inst.group, "", &audio_source_func_type); dev = create_function_device("f_audio_source"); if (IS_ERR(dev)) { err_ptr = dev; goto fail_audio_config; } fi_audio->config->card = -1; fi_audio->config->device = -1; fi_audio->audio_device = dev; attrs = audio_source_function_attributes; if (attrs) { while ((attr = *attrs++) && !err) err = device_create_file(dev, attr); if (err) { err_ptr = ERR_PTR(-EINVAL); goto fail_device; } } dev_set_drvdata(dev, fi_audio); _audio_dev.config = fi_audio->config; return &fi_audio->func_inst; fail_device: device_destroy(dev->class, dev->devt); fail_audio_config: kfree(fi_audio->config); fail_audio: kfree(fi_audio); return err_ptr; } static struct usb_function *audio_source_alloc(struct usb_function_instance *fi) { return &_audio_dev.func; } DECLARE_USB_FUNCTION_INIT(audio_source, audio_source_alloc_inst, audio_source_alloc); MODULE_LICENSE("GPL");