diff options
Diffstat (limited to '')
| -rw-r--r-- | sound/usb/endpoint.c | 1233 |
1 files changed, 1233 insertions, 0 deletions
diff --git a/sound/usb/endpoint.c b/sound/usb/endpoint.c new file mode 100644 index 000000000..727ef9889 --- /dev/null +++ b/sound/usb/endpoint.c @@ -0,0 +1,1233 @@ +/* + * 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. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + * + */ + +#include <linux/gfp.h> +#include <linux/init.h> +#include <linux/ratelimit.h> +#include <linux/usb.h> +#include <linux/usb/audio.h> +#include <linux/slab.h> + +#include <sound/core.h> +#include <sound/pcm.h> +#include <sound/pcm_params.h> + +#include "usbaudio.h" +#include "helper.h" +#include "card.h" +#include "endpoint.h" +#include "pcm.h" +#include "quirks.h" + +#define EP_FLAG_RUNNING 1 +#define EP_FLAG_STOPPING 2 + +/* + * snd_usb_endpoint is a model that abstracts everything related to an + * USB endpoint and its streaming. + * + * There are functions to activate and deactivate the streaming URBs and + * optional callbacks to let the pcm logic handle the actual content of the + * packets for playback and record. Thus, the bus streaming and the audio + * handlers are fully decoupled. + * + * There are two different types of endpoints in audio applications. + * + * SND_USB_ENDPOINT_TYPE_DATA handles full audio data payload for both + * inbound and outbound traffic. + * + * SND_USB_ENDPOINT_TYPE_SYNC endpoints are for inbound traffic only and + * expect the payload to carry Q10.14 / Q16.16 formatted sync information + * (3 or 4 bytes). + * + * Each endpoint has to be configured prior to being used by calling + * snd_usb_endpoint_set_params(). + * + * The model incorporates a reference counting, so that multiple users + * can call snd_usb_endpoint_start() and snd_usb_endpoint_stop(), and + * only the first user will effectively start the URBs, and only the last + * one to stop it will tear the URBs down again. + */ + +/* + * convert a sampling rate into our full speed format (fs/1000 in Q16.16) + * this will overflow at approx 524 kHz + */ +static inline unsigned get_usb_full_speed_rate(unsigned int rate) +{ + return ((rate << 13) + 62) / 125; +} + +/* + * convert a sampling rate into USB high speed format (fs/8000 in Q16.16) + * this will overflow at approx 4 MHz + */ +static inline unsigned get_usb_high_speed_rate(unsigned int rate) +{ + return ((rate << 10) + 62) / 125; +} + +/* + * release a urb data + */ +static void release_urb_ctx(struct snd_urb_ctx *u) +{ + if (u->buffer_size) + usb_free_coherent(u->ep->chip->dev, u->buffer_size, + u->urb->transfer_buffer, + u->urb->transfer_dma); + usb_free_urb(u->urb); + u->urb = NULL; +} + +static const char *usb_error_string(int err) +{ + switch (err) { + case -ENODEV: + return "no device"; + case -ENOENT: + return "endpoint not enabled"; + case -EPIPE: + return "endpoint stalled"; + case -ENOSPC: + return "not enough bandwidth"; + case -ESHUTDOWN: + return "device disabled"; + case -EHOSTUNREACH: + return "device suspended"; + case -EINVAL: + case -EAGAIN: + case -EFBIG: + case -EMSGSIZE: + return "internal error"; + default: + return "unknown error"; + } +} + +/** + * snd_usb_endpoint_implicit_feedback_sink: Report endpoint usage type + * + * @ep: The snd_usb_endpoint + * + * Determine whether an endpoint is driven by an implicit feedback + * data endpoint source. + */ +int snd_usb_endpoint_implicit_feedback_sink(struct snd_usb_endpoint *ep) +{ + return ep->sync_master && + ep->sync_master->type == SND_USB_ENDPOINT_TYPE_DATA && + ep->type == SND_USB_ENDPOINT_TYPE_DATA && + usb_pipeout(ep->pipe); +} + +/* + * For streaming based on information derived from sync endpoints, + * prepare_outbound_urb_sizes() will call next_packet_size() to + * determine the number of samples to be sent in the next packet. + * + * For implicit feedback, next_packet_size() is unused. + */ +int snd_usb_endpoint_next_packet_size(struct snd_usb_endpoint *ep) +{ + unsigned long flags; + int ret; + + if (ep->fill_max) + return ep->maxframesize; + + spin_lock_irqsave(&ep->lock, flags); + ep->phase = (ep->phase & 0xffff) + + (ep->freqm << ep->datainterval); + ret = min(ep->phase >> 16, ep->maxframesize); + spin_unlock_irqrestore(&ep->lock, flags); + + return ret; +} + +static void retire_outbound_urb(struct snd_usb_endpoint *ep, + struct snd_urb_ctx *urb_ctx) +{ + if (ep->retire_data_urb) + ep->retire_data_urb(ep->data_subs, urb_ctx->urb); +} + +static void retire_inbound_urb(struct snd_usb_endpoint *ep, + struct snd_urb_ctx *urb_ctx) +{ + struct urb *urb = urb_ctx->urb; + + if (unlikely(ep->skip_packets > 0)) { + ep->skip_packets--; + return; + } + + if (ep->sync_slave) + snd_usb_handle_sync_urb(ep->sync_slave, ep, urb); + + if (ep->retire_data_urb) + ep->retire_data_urb(ep->data_subs, urb); +} + +static void prepare_silent_urb(struct snd_usb_endpoint *ep, + struct snd_urb_ctx *ctx) +{ + struct urb *urb = ctx->urb; + unsigned int offs = 0; + unsigned int extra = 0; + __le32 packet_length; + int i; + + /* For tx_length_quirk, put packet length at start of packet */ + if (ep->chip->tx_length_quirk) + extra = sizeof(packet_length); + + for (i = 0; i < ctx->packets; ++i) { + unsigned int offset; + unsigned int length; + int counts; + + if (ctx->packet_size[i]) + counts = ctx->packet_size[i]; + else + counts = snd_usb_endpoint_next_packet_size(ep); + + length = counts * ep->stride; /* number of silent bytes */ + offset = offs * ep->stride + extra * i; + urb->iso_frame_desc[i].offset = offset; + urb->iso_frame_desc[i].length = length + extra; + if (extra) { + packet_length = cpu_to_le32(length); + memcpy(urb->transfer_buffer + offset, + &packet_length, sizeof(packet_length)); + } + memset(urb->transfer_buffer + offset + extra, + ep->silence_value, length); + offs += counts; + } + + urb->number_of_packets = ctx->packets; + urb->transfer_buffer_length = offs * ep->stride + ctx->packets * extra; +} + +/* + * Prepare a PLAYBACK urb for submission to the bus. + */ +static void prepare_outbound_urb(struct snd_usb_endpoint *ep, + struct snd_urb_ctx *ctx) +{ + struct urb *urb = ctx->urb; + unsigned char *cp = urb->transfer_buffer; + + urb->dev = ep->chip->dev; /* we need to set this at each time */ + + switch (ep->type) { + case SND_USB_ENDPOINT_TYPE_DATA: + if (ep->prepare_data_urb) { + ep->prepare_data_urb(ep->data_subs, urb); + } else { + /* no data provider, so send silence */ + prepare_silent_urb(ep, ctx); + } + break; + + case SND_USB_ENDPOINT_TYPE_SYNC: + if (snd_usb_get_speed(ep->chip->dev) >= USB_SPEED_HIGH) { + /* + * fill the length and offset of each urb descriptor. + * the fixed 12.13 frequency is passed as 16.16 through the pipe. + */ + urb->iso_frame_desc[0].length = 4; + urb->iso_frame_desc[0].offset = 0; + cp[0] = ep->freqn; + cp[1] = ep->freqn >> 8; + cp[2] = ep->freqn >> 16; + cp[3] = ep->freqn >> 24; + } else { + /* + * fill the length and offset of each urb descriptor. + * the fixed 10.14 frequency is passed through the pipe. + */ + urb->iso_frame_desc[0].length = 3; + urb->iso_frame_desc[0].offset = 0; + cp[0] = ep->freqn >> 2; + cp[1] = ep->freqn >> 10; + cp[2] = ep->freqn >> 18; + } + + break; + } +} + +/* + * Prepare a CAPTURE or SYNC urb for submission to the bus. + */ +static inline void prepare_inbound_urb(struct snd_usb_endpoint *ep, + struct snd_urb_ctx *urb_ctx) +{ + int i, offs; + struct urb *urb = urb_ctx->urb; + + urb->dev = ep->chip->dev; /* we need to set this at each time */ + + switch (ep->type) { + case SND_USB_ENDPOINT_TYPE_DATA: + offs = 0; + for (i = 0; i < urb_ctx->packets; i++) { + urb->iso_frame_desc[i].offset = offs; + urb->iso_frame_desc[i].length = ep->curpacksize; + offs += ep->curpacksize; + } + + urb->transfer_buffer_length = offs; + urb->number_of_packets = urb_ctx->packets; + break; + + case SND_USB_ENDPOINT_TYPE_SYNC: + urb->iso_frame_desc[0].length = min(4u, ep->syncmaxsize); + urb->iso_frame_desc[0].offset = 0; + break; + } +} + +/* + * Send output urbs that have been prepared previously. URBs are dequeued + * from ep->ready_playback_urbs and in case there there aren't any available + * or there are no packets that have been prepared, this function does + * nothing. + * + * The reason why the functionality of sending and preparing URBs is separated + * is that host controllers don't guarantee the order in which they return + * inbound and outbound packets to their submitters. + * + * This function is only used for implicit feedback endpoints. For endpoints + * driven by dedicated sync endpoints, URBs are immediately re-submitted + * from their completion handler. + */ +static void queue_pending_output_urbs(struct snd_usb_endpoint *ep) +{ + while (test_bit(EP_FLAG_RUNNING, &ep->flags)) { + + unsigned long flags; + struct snd_usb_packet_info *uninitialized_var(packet); + struct snd_urb_ctx *ctx = NULL; + int err, i; + + spin_lock_irqsave(&ep->lock, flags); + if (ep->next_packet_read_pos != ep->next_packet_write_pos) { + packet = ep->next_packet + ep->next_packet_read_pos; + ep->next_packet_read_pos++; + ep->next_packet_read_pos %= MAX_URBS; + + /* take URB out of FIFO */ + if (!list_empty(&ep->ready_playback_urbs)) { + ctx = list_first_entry(&ep->ready_playback_urbs, + struct snd_urb_ctx, ready_list); + list_del_init(&ctx->ready_list); + } + } + spin_unlock_irqrestore(&ep->lock, flags); + + if (ctx == NULL) + return; + + /* copy over the length information */ + for (i = 0; i < packet->packets; i++) + ctx->packet_size[i] = packet->packet_size[i]; + + /* call the data handler to fill in playback data */ + prepare_outbound_urb(ep, ctx); + + err = usb_submit_urb(ctx->urb, GFP_ATOMIC); + if (err < 0) + usb_audio_err(ep->chip, + "Unable to submit urb #%d: %d (urb %p)\n", + ctx->index, err, ctx->urb); + else + set_bit(ctx->index, &ep->active_mask); + } +} + +/* + * complete callback for urbs + */ +static void snd_complete_urb(struct urb *urb) +{ + struct snd_urb_ctx *ctx = urb->context; + struct snd_usb_endpoint *ep = ctx->ep; + struct snd_pcm_substream *substream; + unsigned long flags; + int err; + + if (unlikely(urb->status == -ENOENT || /* unlinked */ + urb->status == -ENODEV || /* device removed */ + urb->status == -ECONNRESET || /* unlinked */ + urb->status == -ESHUTDOWN)) /* device disabled */ + goto exit_clear; + /* device disconnected */ + if (unlikely(atomic_read(&ep->chip->shutdown))) + goto exit_clear; + + if (unlikely(!test_bit(EP_FLAG_RUNNING, &ep->flags))) + goto exit_clear; + + if (usb_pipeout(ep->pipe)) { + retire_outbound_urb(ep, ctx); + /* can be stopped during retire callback */ + if (unlikely(!test_bit(EP_FLAG_RUNNING, &ep->flags))) + goto exit_clear; + + if (snd_usb_endpoint_implicit_feedback_sink(ep)) { + spin_lock_irqsave(&ep->lock, flags); + list_add_tail(&ctx->ready_list, &ep->ready_playback_urbs); + spin_unlock_irqrestore(&ep->lock, flags); + queue_pending_output_urbs(ep); + + goto exit_clear; + } + + prepare_outbound_urb(ep, ctx); + /* can be stopped during prepare callback */ + if (unlikely(!test_bit(EP_FLAG_RUNNING, &ep->flags))) + goto exit_clear; + } else { + retire_inbound_urb(ep, ctx); + /* can be stopped during retire callback */ + if (unlikely(!test_bit(EP_FLAG_RUNNING, &ep->flags))) + goto exit_clear; + + prepare_inbound_urb(ep, ctx); + } + + err = usb_submit_urb(urb, GFP_ATOMIC); + if (err == 0) + return; + + usb_audio_err(ep->chip, "cannot submit urb (err = %d)\n", err); + if (ep->data_subs && ep->data_subs->pcm_substream) { + substream = ep->data_subs->pcm_substream; + snd_pcm_stop_xrun(substream); + } + +exit_clear: + clear_bit(ctx->index, &ep->active_mask); +} + +/** + * snd_usb_add_endpoint: Add an endpoint to an USB audio chip + * + * @chip: The chip + * @alts: The USB host interface + * @ep_num: The number of the endpoint to use + * @direction: SNDRV_PCM_STREAM_PLAYBACK or SNDRV_PCM_STREAM_CAPTURE + * @type: SND_USB_ENDPOINT_TYPE_DATA or SND_USB_ENDPOINT_TYPE_SYNC + * + * If the requested endpoint has not been added to the given chip before, + * a new instance is created. Otherwise, a pointer to the previoulsy + * created instance is returned. In case of any error, NULL is returned. + * + * New endpoints will be added to chip->ep_list and must be freed by + * calling snd_usb_endpoint_free(). + * + * For SND_USB_ENDPOINT_TYPE_SYNC, the caller needs to guarantee that + * bNumEndpoints > 1 beforehand. + */ +struct snd_usb_endpoint *snd_usb_add_endpoint(struct snd_usb_audio *chip, + struct usb_host_interface *alts, + int ep_num, int direction, int type) +{ + struct snd_usb_endpoint *ep; + int is_playback = direction == SNDRV_PCM_STREAM_PLAYBACK; + + if (WARN_ON(!alts)) + return NULL; + + mutex_lock(&chip->mutex); + + list_for_each_entry(ep, &chip->ep_list, list) { + if (ep->ep_num == ep_num && + ep->iface == alts->desc.bInterfaceNumber && + ep->altsetting == alts->desc.bAlternateSetting) { + usb_audio_dbg(ep->chip, + "Re-using EP %x in iface %d,%d @%p\n", + ep_num, ep->iface, ep->altsetting, ep); + goto __exit_unlock; + } + } + + usb_audio_dbg(chip, "Creating new %s %s endpoint #%x\n", + is_playback ? "playback" : "capture", + type == SND_USB_ENDPOINT_TYPE_DATA ? "data" : "sync", + ep_num); + + ep = kzalloc(sizeof(*ep), GFP_KERNEL); + if (!ep) + goto __exit_unlock; + + ep->chip = chip; + spin_lock_init(&ep->lock); + ep->type = type; + ep->ep_num = ep_num; + ep->iface = alts->desc.bInterfaceNumber; + ep->altsetting = alts->desc.bAlternateSetting; + INIT_LIST_HEAD(&ep->ready_playback_urbs); + ep_num &= USB_ENDPOINT_NUMBER_MASK; + + if (is_playback) + ep->pipe = usb_sndisocpipe(chip->dev, ep_num); + else + ep->pipe = usb_rcvisocpipe(chip->dev, ep_num); + + if (type == SND_USB_ENDPOINT_TYPE_SYNC) { + if (get_endpoint(alts, 1)->bLength >= USB_DT_ENDPOINT_AUDIO_SIZE && + get_endpoint(alts, 1)->bRefresh >= 1 && + get_endpoint(alts, 1)->bRefresh <= 9) + ep->syncinterval = get_endpoint(alts, 1)->bRefresh; + else if (snd_usb_get_speed(chip->dev) == USB_SPEED_FULL) + ep->syncinterval = 1; + else if (get_endpoint(alts, 1)->bInterval >= 1 && + get_endpoint(alts, 1)->bInterval <= 16) + ep->syncinterval = get_endpoint(alts, 1)->bInterval - 1; + else + ep->syncinterval = 3; + + ep->syncmaxsize = le16_to_cpu(get_endpoint(alts, 1)->wMaxPacketSize); + } + + list_add_tail(&ep->list, &chip->ep_list); + +__exit_unlock: + mutex_unlock(&chip->mutex); + + return ep; +} + +/* + * wait until all urbs are processed. + */ +static int wait_clear_urbs(struct snd_usb_endpoint *ep) +{ + unsigned long end_time = jiffies + msecs_to_jiffies(1000); + int alive; + + do { + alive = bitmap_weight(&ep->active_mask, ep->nurbs); + if (!alive) + break; + + schedule_timeout_uninterruptible(1); + } while (time_before(jiffies, end_time)); + + if (alive) + usb_audio_err(ep->chip, + "timeout: still %d active urbs on EP #%x\n", + alive, ep->ep_num); + clear_bit(EP_FLAG_STOPPING, &ep->flags); + + ep->data_subs = NULL; + ep->sync_slave = NULL; + ep->retire_data_urb = NULL; + ep->prepare_data_urb = NULL; + + return 0; +} + +/* sync the pending stop operation; + * this function itself doesn't trigger the stop operation + */ +void snd_usb_endpoint_sync_pending_stop(struct snd_usb_endpoint *ep) +{ + if (ep && test_bit(EP_FLAG_STOPPING, &ep->flags)) + wait_clear_urbs(ep); +} + +/* + * unlink active urbs. + */ +static int deactivate_urbs(struct snd_usb_endpoint *ep, bool force) +{ + unsigned int i; + + if (!force && atomic_read(&ep->chip->shutdown)) /* to be sure... */ + return -EBADFD; + + clear_bit(EP_FLAG_RUNNING, &ep->flags); + + INIT_LIST_HEAD(&ep->ready_playback_urbs); + ep->next_packet_read_pos = 0; + ep->next_packet_write_pos = 0; + + for (i = 0; i < ep->nurbs; i++) { + if (test_bit(i, &ep->active_mask)) { + if (!test_and_set_bit(i, &ep->unlink_mask)) { + struct urb *u = ep->urb[i].urb; + usb_unlink_urb(u); + } + } + } + + return 0; +} + +/* + * release an endpoint's urbs + */ +static void release_urbs(struct snd_usb_endpoint *ep, int force) +{ + int i; + + /* route incoming urbs to nirvana */ + ep->retire_data_urb = NULL; + ep->prepare_data_urb = NULL; + + /* stop urbs */ + deactivate_urbs(ep, force); + wait_clear_urbs(ep); + + for (i = 0; i < ep->nurbs; i++) + release_urb_ctx(&ep->urb[i]); + + if (ep->syncbuf) + usb_free_coherent(ep->chip->dev, SYNC_URBS * 4, + ep->syncbuf, ep->sync_dma); + + ep->syncbuf = NULL; + ep->nurbs = 0; +} + +/* + * configure a data endpoint + */ +static int data_ep_set_params(struct snd_usb_endpoint *ep, + snd_pcm_format_t pcm_format, + unsigned int channels, + unsigned int period_bytes, + unsigned int frames_per_period, + unsigned int periods_per_buffer, + struct audioformat *fmt, + struct snd_usb_endpoint *sync_ep) +{ + unsigned int maxsize, minsize, packs_per_ms, max_packs_per_urb; + unsigned int max_packs_per_period, urbs_per_period, urb_packs; + unsigned int max_urbs, i; + int frame_bits = snd_pcm_format_physical_width(pcm_format) * channels; + int tx_length_quirk = (ep->chip->tx_length_quirk && + usb_pipeout(ep->pipe)); + + if (pcm_format == SNDRV_PCM_FORMAT_DSD_U16_LE && fmt->dsd_dop) { + /* + * When operating in DSD DOP mode, the size of a sample frame + * in hardware differs from the actual physical format width + * because we need to make room for the DOP markers. + */ + frame_bits += channels << 3; + } + + ep->datainterval = fmt->datainterval; + ep->stride = frame_bits >> 3; + + switch (pcm_format) { + case SNDRV_PCM_FORMAT_U8: + ep->silence_value = 0x80; + break; + case SNDRV_PCM_FORMAT_DSD_U8: + case SNDRV_PCM_FORMAT_DSD_U16_LE: + case SNDRV_PCM_FORMAT_DSD_U32_LE: + case SNDRV_PCM_FORMAT_DSD_U16_BE: + case SNDRV_PCM_FORMAT_DSD_U32_BE: + ep->silence_value = 0x69; + break; + default: + ep->silence_value = 0; + } + + /* assume max. frequency is 50% higher than nominal */ + ep->freqmax = ep->freqn + (ep->freqn >> 1); + /* Round up freqmax to nearest integer in order to calculate maximum + * packet size, which must represent a whole number of frames. + * This is accomplished by adding 0x0.ffff before converting the + * Q16.16 format into integer. + * In order to accurately calculate the maximum packet size when + * the data interval is more than 1 (i.e. ep->datainterval > 0), + * multiply by the data interval prior to rounding. For instance, + * a freqmax of 41 kHz will result in a max packet size of 6 (5.125) + * frames with a data interval of 1, but 11 (10.25) frames with a + * data interval of 2. + * (ep->freqmax << ep->datainterval overflows at 8.192 MHz for the + * maximum datainterval value of 3, at USB full speed, higher for + * USB high speed, noting that ep->freqmax is in units of + * frames per packet in Q16.16 format.) + */ + maxsize = (((ep->freqmax << ep->datainterval) + 0xffff) >> 16) * + (frame_bits >> 3); + if (tx_length_quirk) + maxsize += sizeof(__le32); /* Space for length descriptor */ + /* but wMaxPacketSize might reduce this */ + if (ep->maxpacksize && ep->maxpacksize < maxsize) { + /* whatever fits into a max. size packet */ + unsigned int data_maxsize = maxsize = ep->maxpacksize; + + if (tx_length_quirk) + /* Need to remove the length descriptor to calc freq */ + data_maxsize -= sizeof(__le32); + ep->freqmax = (data_maxsize / (frame_bits >> 3)) + << (16 - ep->datainterval); + } + + if (ep->fill_max) + ep->curpacksize = ep->maxpacksize; + else + ep->curpacksize = maxsize; + + if (snd_usb_get_speed(ep->chip->dev) != USB_SPEED_FULL) { + packs_per_ms = 8 >> ep->datainterval; + max_packs_per_urb = MAX_PACKS_HS; + } else { + packs_per_ms = 1; + max_packs_per_urb = MAX_PACKS; + } + if (sync_ep && !snd_usb_endpoint_implicit_feedback_sink(ep)) + max_packs_per_urb = min(max_packs_per_urb, + 1U << sync_ep->syncinterval); + max_packs_per_urb = max(1u, max_packs_per_urb >> ep->datainterval); + + /* + * Capture endpoints need to use small URBs because there's no way + * to tell in advance where the next period will end, and we don't + * want the next URB to complete much after the period ends. + * + * Playback endpoints with implicit sync much use the same parameters + * as their corresponding capture endpoint. + */ + if (usb_pipein(ep->pipe) || + snd_usb_endpoint_implicit_feedback_sink(ep)) { + + urb_packs = packs_per_ms; + /* + * Wireless devices can poll at a max rate of once per 4ms. + * For dataintervals less than 5, increase the packet count to + * allow the host controller to use bursting to fill in the + * gaps. + */ + if (snd_usb_get_speed(ep->chip->dev) == USB_SPEED_WIRELESS) { + int interval = ep->datainterval; + while (interval < 5) { + urb_packs <<= 1; + ++interval; + } + } + /* make capture URBs <= 1 ms and smaller than a period */ + urb_packs = min(max_packs_per_urb, urb_packs); + while (urb_packs > 1 && urb_packs * maxsize >= period_bytes) + urb_packs >>= 1; + ep->nurbs = MAX_URBS; + + /* + * Playback endpoints without implicit sync are adjusted so that + * a period fits as evenly as possible in the smallest number of + * URBs. The total number of URBs is adjusted to the size of the + * ALSA buffer, subject to the MAX_URBS and MAX_QUEUE limits. + */ + } else { + /* determine how small a packet can be */ + minsize = (ep->freqn >> (16 - ep->datainterval)) * + (frame_bits >> 3); + /* with sync from device, assume it can be 12% lower */ + if (sync_ep) + minsize -= minsize >> 3; + minsize = max(minsize, 1u); + + /* how many packets will contain an entire ALSA period? */ + max_packs_per_period = DIV_ROUND_UP(period_bytes, minsize); + + /* how many URBs will contain a period? */ + urbs_per_period = DIV_ROUND_UP(max_packs_per_period, + max_packs_per_urb); + /* how many packets are needed in each URB? */ + urb_packs = DIV_ROUND_UP(max_packs_per_period, urbs_per_period); + + /* limit the number of frames in a single URB */ + ep->max_urb_frames = DIV_ROUND_UP(frames_per_period, + urbs_per_period); + + /* try to use enough URBs to contain an entire ALSA buffer */ + max_urbs = min((unsigned) MAX_URBS, + MAX_QUEUE * packs_per_ms / urb_packs); + ep->nurbs = min(max_urbs, urbs_per_period * periods_per_buffer); + } + + /* allocate and initialize data urbs */ + for (i = 0; i < ep->nurbs; i++) { + struct snd_urb_ctx *u = &ep->urb[i]; + u->index = i; + u->ep = ep; + u->packets = urb_packs; + u->buffer_size = maxsize * u->packets; + + if (fmt->fmt_type == UAC_FORMAT_TYPE_II) + u->packets++; /* for transfer delimiter */ + u->urb = usb_alloc_urb(u->packets, GFP_KERNEL); + if (!u->urb) + goto out_of_memory; + + u->urb->transfer_buffer = + usb_alloc_coherent(ep->chip->dev, u->buffer_size, + GFP_KERNEL, &u->urb->transfer_dma); + if (!u->urb->transfer_buffer) + goto out_of_memory; + u->urb->pipe = ep->pipe; + u->urb->transfer_flags = URB_NO_TRANSFER_DMA_MAP; + u->urb->interval = 1 << ep->datainterval; + u->urb->context = u; + u->urb->complete = snd_complete_urb; + INIT_LIST_HEAD(&u->ready_list); + } + + return 0; + +out_of_memory: + release_urbs(ep, 0); + return -ENOMEM; +} + +/* + * configure a sync endpoint + */ +static int sync_ep_set_params(struct snd_usb_endpoint *ep) +{ + int i; + + ep->syncbuf = usb_alloc_coherent(ep->chip->dev, SYNC_URBS * 4, + GFP_KERNEL, &ep->sync_dma); + if (!ep->syncbuf) + return -ENOMEM; + + for (i = 0; i < SYNC_URBS; i++) { + struct snd_urb_ctx *u = &ep->urb[i]; + u->index = i; + u->ep = ep; + u->packets = 1; + u->urb = usb_alloc_urb(1, GFP_KERNEL); + if (!u->urb) + goto out_of_memory; + u->urb->transfer_buffer = ep->syncbuf + i * 4; + u->urb->transfer_dma = ep->sync_dma + i * 4; + u->urb->transfer_buffer_length = 4; + u->urb->pipe = ep->pipe; + u->urb->transfer_flags = URB_NO_TRANSFER_DMA_MAP; + u->urb->number_of_packets = 1; + u->urb->interval = 1 << ep->syncinterval; + u->urb->context = u; + u->urb->complete = snd_complete_urb; + } + + ep->nurbs = SYNC_URBS; + + return 0; + +out_of_memory: + release_urbs(ep, 0); + return -ENOMEM; +} + +/** + * snd_usb_endpoint_set_params: configure an snd_usb_endpoint + * + * @ep: the snd_usb_endpoint to configure + * @pcm_format: the audio fomat. + * @channels: the number of audio channels. + * @period_bytes: the number of bytes in one alsa period. + * @period_frames: the number of frames in one alsa period. + * @buffer_periods: the number of periods in one alsa buffer. + * @rate: the frame rate. + * @fmt: the USB audio format information + * @sync_ep: the sync endpoint to use, if any + * + * Determine the number of URBs to be used on this endpoint. + * An endpoint must be configured before it can be started. + * An endpoint that is already running can not be reconfigured. + */ +int snd_usb_endpoint_set_params(struct snd_usb_endpoint *ep, + snd_pcm_format_t pcm_format, + unsigned int channels, + unsigned int period_bytes, + unsigned int period_frames, + unsigned int buffer_periods, + unsigned int rate, + struct audioformat *fmt, + struct snd_usb_endpoint *sync_ep) +{ + int err; + + if (ep->use_count != 0) { + usb_audio_warn(ep->chip, + "Unable to change format on ep #%x: already in use\n", + ep->ep_num); + return -EBUSY; + } + + /* release old buffers, if any */ + release_urbs(ep, 0); + + ep->datainterval = fmt->datainterval; + ep->maxpacksize = fmt->maxpacksize; + ep->fill_max = !!(fmt->attributes & UAC_EP_CS_ATTR_FILL_MAX); + + if (snd_usb_get_speed(ep->chip->dev) == USB_SPEED_FULL) + ep->freqn = get_usb_full_speed_rate(rate); + else + ep->freqn = get_usb_high_speed_rate(rate); + + /* calculate the frequency in 16.16 format */ + ep->freqm = ep->freqn; + ep->freqshift = INT_MIN; + + ep->phase = 0; + + switch (ep->type) { + case SND_USB_ENDPOINT_TYPE_DATA: + err = data_ep_set_params(ep, pcm_format, channels, + period_bytes, period_frames, + buffer_periods, fmt, sync_ep); + break; + case SND_USB_ENDPOINT_TYPE_SYNC: + err = sync_ep_set_params(ep); + break; + default: + err = -EINVAL; + } + + usb_audio_dbg(ep->chip, + "Setting params for ep #%x (type %d, %d urbs), ret=%d\n", + ep->ep_num, ep->type, ep->nurbs, err); + + return err; +} + +/** + * snd_usb_endpoint_start: start an snd_usb_endpoint + * + * @ep: the endpoint to start + * + * A call to this function will increment the use count of the endpoint. + * In case it is not already running, the URBs for this endpoint will be + * submitted. Otherwise, this function does nothing. + * + * Must be balanced to calls of snd_usb_endpoint_stop(). + * + * Returns an error if the URB submission failed, 0 in all other cases. + */ +int snd_usb_endpoint_start(struct snd_usb_endpoint *ep) +{ + int err; + unsigned int i; + + if (atomic_read(&ep->chip->shutdown)) + return -EBADFD; + + /* already running? */ + if (++ep->use_count != 1) + return 0; + + /* just to be sure */ + deactivate_urbs(ep, false); + + ep->active_mask = 0; + ep->unlink_mask = 0; + ep->phase = 0; + + snd_usb_endpoint_start_quirk(ep); + + /* + * If this endpoint has a data endpoint as implicit feedback source, + * don't start the urbs here. Instead, mark them all as available, + * wait for the record urbs to return and queue the playback urbs + * from that context. + */ + + set_bit(EP_FLAG_RUNNING, &ep->flags); + + if (snd_usb_endpoint_implicit_feedback_sink(ep)) { + for (i = 0; i < ep->nurbs; i++) { + struct snd_urb_ctx *ctx = ep->urb + i; + list_add_tail(&ctx->ready_list, &ep->ready_playback_urbs); + } + + return 0; + } + + for (i = 0; i < ep->nurbs; i++) { + struct urb *urb = ep->urb[i].urb; + + if (snd_BUG_ON(!urb)) + goto __error; + + if (usb_pipeout(ep->pipe)) { + prepare_outbound_urb(ep, urb->context); + } else { + prepare_inbound_urb(ep, urb->context); + } + + err = usb_submit_urb(urb, GFP_ATOMIC); + if (err < 0) { + usb_audio_err(ep->chip, + "cannot submit urb %d, error %d: %s\n", + i, err, usb_error_string(err)); + goto __error; + } + set_bit(i, &ep->active_mask); + } + + return 0; + +__error: + clear_bit(EP_FLAG_RUNNING, &ep->flags); + ep->use_count--; + deactivate_urbs(ep, false); + return -EPIPE; +} + +/** + * snd_usb_endpoint_stop: stop an snd_usb_endpoint + * + * @ep: the endpoint to stop (may be NULL) + * + * A call to this function will decrement the use count of the endpoint. + * In case the last user has requested the endpoint stop, the URBs will + * actually be deactivated. + * + * Must be balanced to calls of snd_usb_endpoint_start(). + * + * The caller needs to synchronize the pending stop operation via + * snd_usb_endpoint_sync_pending_stop(). + */ +void snd_usb_endpoint_stop(struct snd_usb_endpoint *ep) +{ + if (!ep) + return; + + if (snd_BUG_ON(ep->use_count == 0)) + return; + + if (--ep->use_count == 0) { + deactivate_urbs(ep, false); + set_bit(EP_FLAG_STOPPING, &ep->flags); + } +} + +/** + * snd_usb_endpoint_deactivate: deactivate an snd_usb_endpoint + * + * @ep: the endpoint to deactivate + * + * If the endpoint is not currently in use, this functions will + * deactivate its associated URBs. + * + * In case of any active users, this functions does nothing. + */ +void snd_usb_endpoint_deactivate(struct snd_usb_endpoint *ep) +{ + if (!ep) + return; + + if (ep->use_count != 0) + return; + + deactivate_urbs(ep, true); + wait_clear_urbs(ep); +} + +/** + * snd_usb_endpoint_release: Tear down an snd_usb_endpoint + * + * @ep: the endpoint to release + * + * This function does not care for the endpoint's use count but will tear + * down all the streaming URBs immediately. + */ +void snd_usb_endpoint_release(struct snd_usb_endpoint *ep) +{ + release_urbs(ep, 1); +} + +/** + * snd_usb_endpoint_free: Free the resources of an snd_usb_endpoint + * + * @ep: the endpoint to free + * + * This free all resources of the given ep. + */ +void snd_usb_endpoint_free(struct snd_usb_endpoint *ep) +{ + kfree(ep); +} + +/** + * snd_usb_handle_sync_urb: parse an USB sync packet + * + * @ep: the endpoint to handle the packet + * @sender: the sending endpoint + * @urb: the received packet + * + * This function is called from the context of an endpoint that received + * the packet and is used to let another endpoint object handle the payload. + */ +void snd_usb_handle_sync_urb(struct snd_usb_endpoint *ep, + struct snd_usb_endpoint *sender, + const struct urb *urb) +{ + int shift; + unsigned int f; + unsigned long flags; + + snd_BUG_ON(ep == sender); + + /* + * In case the endpoint is operating in implicit feedback mode, prepare + * a new outbound URB that has the same layout as the received packet + * and add it to the list of pending urbs. queue_pending_output_urbs() + * will take care of them later. + */ + if (snd_usb_endpoint_implicit_feedback_sink(ep) && + ep->use_count != 0) { + + /* implicit feedback case */ + int i, bytes = 0; + struct snd_urb_ctx *in_ctx; + struct snd_usb_packet_info *out_packet; + + in_ctx = urb->context; + + /* Count overall packet size */ + for (i = 0; i < in_ctx->packets; i++) + if (urb->iso_frame_desc[i].status == 0) + bytes += urb->iso_frame_desc[i].actual_length; + + /* + * skip empty packets. At least M-Audio's Fast Track Ultra stops + * streaming once it received a 0-byte OUT URB + */ + if (bytes == 0) + return; + + spin_lock_irqsave(&ep->lock, flags); + out_packet = ep->next_packet + ep->next_packet_write_pos; + + /* + * Iterate through the inbound packet and prepare the lengths + * for the output packet. The OUT packet we are about to send + * will have the same amount of payload bytes per stride as the + * IN packet we just received. Since the actual size is scaled + * by the stride, use the sender stride to calculate the length + * in case the number of channels differ between the implicitly + * fed-back endpoint and the synchronizing endpoint. + */ + + out_packet->packets = in_ctx->packets; + for (i = 0; i < in_ctx->packets; i++) { + if (urb->iso_frame_desc[i].status == 0) + out_packet->packet_size[i] = + urb->iso_frame_desc[i].actual_length / sender->stride; + else + out_packet->packet_size[i] = 0; + } + + ep->next_packet_write_pos++; + ep->next_packet_write_pos %= MAX_URBS; + spin_unlock_irqrestore(&ep->lock, flags); + queue_pending_output_urbs(ep); + + return; + } + + /* + * process after playback sync complete + * + * Full speed devices report feedback values in 10.14 format as samples + * per frame, high speed devices in 16.16 format as samples per + * microframe. + * + * Because the Audio Class 1 spec was written before USB 2.0, many high + * speed devices use a wrong interpretation, some others use an + * entirely different format. + * + * Therefore, we cannot predict what format any particular device uses + * and must detect it automatically. + */ + + if (urb->iso_frame_desc[0].status != 0 || + urb->iso_frame_desc[0].actual_length < 3) + return; + + f = le32_to_cpup(urb->transfer_buffer); + if (urb->iso_frame_desc[0].actual_length == 3) + f &= 0x00ffffff; + else + f &= 0x0fffffff; + + if (f == 0) + return; + + if (unlikely(sender->tenor_fb_quirk)) { + /* + * Devices based on Tenor 8802 chipsets (TEAC UD-H01 + * and others) sometimes change the feedback value + * by +/- 0x1.0000. + */ + if (f < ep->freqn - 0x8000) + f += 0xf000; + else if (f > ep->freqn + 0x8000) + f -= 0xf000; + } else if (unlikely(ep->freqshift == INT_MIN)) { + /* + * The first time we see a feedback value, determine its format + * by shifting it left or right until it matches the nominal + * frequency value. This assumes that the feedback does not + * differ from the nominal value more than +50% or -25%. + */ + shift = 0; + while (f < ep->freqn - ep->freqn / 4) { + f <<= 1; + shift++; + } + while (f > ep->freqn + ep->freqn / 2) { + f >>= 1; + shift--; + } + ep->freqshift = shift; + } else if (ep->freqshift >= 0) + f <<= ep->freqshift; + else + f >>= -ep->freqshift; + + if (likely(f >= ep->freqn - ep->freqn / 8 && f <= ep->freqmax)) { + /* + * If the frequency looks valid, set it. + * This value is referred to in prepare_playback_urb(). + */ + spin_lock_irqsave(&ep->lock, flags); + ep->freqm = f; + spin_unlock_irqrestore(&ep->lock, flags); + } else { + /* + * Out of range; maybe the shift value is wrong. + * Reset it so that we autodetect again the next time. + */ + ep->freqshift = INT_MIN; + } +} + |