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![Markus Grabner](/assets/img/avatar_default.png)
There are several features of the Line6 USB driver which require PCM data to be exchanged with the device: *) PCM playback and capture via ALSA *) software monitoring (for devices without hardware monitoring) *) optional impulse response measurement However, from the device's point of view, there is just a single capture and playback stream, which must be shared between these subsystems. It is therefore necessary to maintain the state of the subsystems with respect to PCM usage. We define several constants of the form LINE6_BIT_PCM_<subsystem>_<direction>_<resource> with the following meanings: *) <subsystem> is one of -) ALSA: PCM playback and capture via ALSA -) MONITOR: software monitoring -) IMPULSE: optional impulse response measurement *) <direction> is one of -) PLAYBACK: audio output (from host to device) -) CAPTURE: audio input (from device to host) *) <resource> is one of -) BUFFER: buffer required by PCM data stream -) STREAM: actual PCM data stream The subsystems call line6_pcm_acquire() to acquire the (shared) resources needed for a particular operation (e.g., allocate the buffer for ALSA playback or start the capture stream for software monitoring). When a resource is no longer needed, it is released by calling line6_pcm_release(). Buffer allocation and stream startup are handled separately to allow the ALSA kernel driver to perform them at appropriate places (since the callback which starts a PCM stream is not allowed to sleep). Signed-off-by: Markus Grabner <grabner@icg.tugraz.at> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
586 lines
15 KiB
C
586 lines
15 KiB
C
/*
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* Line6 Linux USB driver - 0.9.1beta
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*
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* Copyright (C) 2004-2010 Markus Grabner (grabner@icg.tugraz.at)
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License as
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* published by the Free Software Foundation, version 2.
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*
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*/
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#include <linux/slab.h>
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#include <sound/core.h>
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#include <sound/pcm.h>
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#include <sound/pcm_params.h>
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#include "audio.h"
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#include "capture.h"
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#include "driver.h"
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#include "pcm.h"
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#include "pod.h"
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#include "playback.h"
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/*
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Software stereo volume control.
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*/
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static void change_volume(struct urb *urb_out, int volume[],
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int bytes_per_frame)
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{
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int chn = 0;
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if (volume[0] == 256 && volume[1] == 256)
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return; /* maximum volume - no change */
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if (bytes_per_frame == 4) {
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short *p, *buf_end;
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p = (short *)urb_out->transfer_buffer;
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buf_end = p + urb_out->transfer_buffer_length / sizeof(*p);
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for (; p < buf_end; ++p) {
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*p = (*p * volume[chn & 1]) >> 8;
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++chn;
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}
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} else if (bytes_per_frame == 6) {
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unsigned char *p, *buf_end;
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p = (unsigned char *)urb_out->transfer_buffer;
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buf_end = p + urb_out->transfer_buffer_length;
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for (; p < buf_end; p += 3) {
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int val;
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val = p[0] + (p[1] << 8) + ((signed char)p[2] << 16);
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val = (val * volume[chn & 1]) >> 8;
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p[0] = val;
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p[1] = val >> 8;
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p[2] = val >> 16;
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++chn;
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}
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}
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}
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#ifdef CONFIG_LINE6_USB_IMPULSE_RESPONSE
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/*
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Create signal for impulse response test.
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*/
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static void create_impulse_test_signal(struct snd_line6_pcm *line6pcm,
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struct urb *urb_out, int bytes_per_frame)
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{
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int frames = urb_out->transfer_buffer_length / bytes_per_frame;
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if (bytes_per_frame == 4) {
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int i;
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short *pi = (short *)line6pcm->prev_fbuf;
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short *po = (short *)urb_out->transfer_buffer;
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for (i = 0; i < frames; ++i) {
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po[0] = pi[0];
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po[1] = 0;
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pi += 2;
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po += 2;
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}
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} else if (bytes_per_frame == 6) {
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int i, j;
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unsigned char *pi = line6pcm->prev_fbuf;
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unsigned char *po = urb_out->transfer_buffer;
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for (i = 0; i < frames; ++i) {
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for (j = 0; j < bytes_per_frame / 2; ++j)
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po[j] = pi[j];
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for (; j < bytes_per_frame; ++j)
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po[j] = 0;
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pi += bytes_per_frame;
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po += bytes_per_frame;
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}
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}
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if (--line6pcm->impulse_count <= 0) {
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((unsigned char *)(urb_out->transfer_buffer))[bytes_per_frame -
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1] =
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line6pcm->impulse_volume;
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line6pcm->impulse_count = line6pcm->impulse_period;
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}
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}
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#endif
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/*
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Add signal to buffer for software monitoring.
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*/
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static void add_monitor_signal(struct urb *urb_out, unsigned char *signal,
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int volume, int bytes_per_frame)
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{
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if (volume == 0)
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return; /* zero volume - no change */
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if (bytes_per_frame == 4) {
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short *pi, *po, *buf_end;
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pi = (short *)signal;
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po = (short *)urb_out->transfer_buffer;
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buf_end = po + urb_out->transfer_buffer_length / sizeof(*po);
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for (; po < buf_end; ++pi, ++po)
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*po += (*pi * volume) >> 8;
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}
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/*
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We don't need to handle devices with 6 bytes per frame here
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since they all support hardware monitoring.
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*/
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}
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/*
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Find a free URB, prepare audio data, and submit URB.
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*/
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static int submit_audio_out_urb(struct snd_line6_pcm *line6pcm)
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{
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int index;
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unsigned long flags;
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int i, urb_size, urb_frames;
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int ret;
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const int bytes_per_frame = line6pcm->properties->bytes_per_frame;
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const int frame_increment =
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line6pcm->properties->snd_line6_rates.rats[0].num_min;
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const int frame_factor =
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line6pcm->properties->snd_line6_rates.rats[0].den *
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(USB_INTERVALS_PER_SECOND / LINE6_ISO_INTERVAL);
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struct urb *urb_out;
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spin_lock_irqsave(&line6pcm->lock_audio_out, flags);
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index =
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find_first_zero_bit(&line6pcm->active_urb_out, LINE6_ISO_BUFFERS);
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if (index < 0 || index >= LINE6_ISO_BUFFERS) {
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spin_unlock_irqrestore(&line6pcm->lock_audio_out, flags);
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dev_err(line6pcm->line6->ifcdev, "no free URB found\n");
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return -EINVAL;
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}
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urb_out = line6pcm->urb_audio_out[index];
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urb_size = 0;
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for (i = 0; i < LINE6_ISO_PACKETS; ++i) {
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/* compute frame size for given sampling rate */
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int fsize = 0;
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struct usb_iso_packet_descriptor *fout =
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&urb_out->iso_frame_desc[i];
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if (line6pcm->flags & LINE6_BITS_CAPTURE_STREAM)
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fsize = line6pcm->prev_fsize;
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if (fsize == 0) {
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int n;
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line6pcm->count_out += frame_increment;
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n = line6pcm->count_out / frame_factor;
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line6pcm->count_out -= n * frame_factor;
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fsize = n * bytes_per_frame;
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}
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fout->offset = urb_size;
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fout->length = fsize;
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urb_size += fsize;
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}
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if (urb_size == 0) {
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/* can't determine URB size */
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spin_unlock_irqrestore(&line6pcm->lock_audio_out, flags);
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dev_err(line6pcm->line6->ifcdev, "driver bug: urb_size = 0\n"); /* this is somewhat paranoid */
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return -EINVAL;
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}
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urb_frames = urb_size / bytes_per_frame;
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urb_out->transfer_buffer =
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line6pcm->buffer_out +
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index * LINE6_ISO_PACKETS * line6pcm->max_packet_size;
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urb_out->transfer_buffer_length = urb_size;
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urb_out->context = line6pcm;
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if (test_bit(LINE6_INDEX_PCM_ALSA_PLAYBACK_STREAM, &line6pcm->flags) &&
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!test_bit(LINE6_INDEX_PAUSE_PLAYBACK, &line6pcm->flags)) {
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struct snd_pcm_runtime *runtime =
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get_substream(line6pcm, SNDRV_PCM_STREAM_PLAYBACK)->runtime;
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if (line6pcm->pos_out + urb_frames > runtime->buffer_size) {
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/*
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The transferred area goes over buffer boundary,
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copy the data to the temp buffer.
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*/
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int len;
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len = runtime->buffer_size - line6pcm->pos_out;
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if (len > 0) {
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memcpy(urb_out->transfer_buffer,
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runtime->dma_area +
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line6pcm->pos_out * bytes_per_frame,
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len * bytes_per_frame);
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memcpy(urb_out->transfer_buffer +
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len * bytes_per_frame, runtime->dma_area,
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(urb_frames - len) * bytes_per_frame);
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} else
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dev_err(line6pcm->line6->ifcdev, "driver bug: len = %d\n", len); /* this is somewhat paranoid */
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} else {
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memcpy(urb_out->transfer_buffer,
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runtime->dma_area +
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line6pcm->pos_out * bytes_per_frame,
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urb_out->transfer_buffer_length);
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}
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line6pcm->pos_out += urb_frames;
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if (line6pcm->pos_out >= runtime->buffer_size)
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line6pcm->pos_out -= runtime->buffer_size;
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} else {
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memset(urb_out->transfer_buffer, 0,
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urb_out->transfer_buffer_length);
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}
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change_volume(urb_out, line6pcm->volume_playback, bytes_per_frame);
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if (line6pcm->prev_fbuf != NULL) {
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#ifdef CONFIG_LINE6_USB_IMPULSE_RESPONSE
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if (line6pcm->flags & LINE6_BITS_PCM_IMPULSE) {
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create_impulse_test_signal(line6pcm, urb_out,
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bytes_per_frame);
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if (line6pcm->flags & LINE6_BIT_PCM_ALSA_CAPTURE_STREAM) {
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line6_capture_copy(line6pcm,
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urb_out->transfer_buffer,
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urb_out->
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transfer_buffer_length);
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line6_capture_check_period(line6pcm,
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urb_out->transfer_buffer_length);
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}
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} else {
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#endif
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if (!
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(line6pcm->line6->
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properties->capabilities & LINE6_BIT_HWMON)
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&& (line6pcm->flags & LINE6_BITS_PLAYBACK_STREAM)
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&& (line6pcm->flags & LINE6_BITS_CAPTURE_STREAM))
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add_monitor_signal(urb_out, line6pcm->prev_fbuf,
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line6pcm->volume_monitor,
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bytes_per_frame);
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#ifdef CONFIG_LINE6_USB_IMPULSE_RESPONSE
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}
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#endif
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}
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#ifdef CONFIG_LINE6_USB_DUMP_PCM
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for (i = 0; i < LINE6_ISO_PACKETS; ++i) {
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struct usb_iso_packet_descriptor *fout =
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&urb_out->iso_frame_desc[i];
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line6_write_hexdump(line6pcm->line6, 'P',
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urb_out->transfer_buffer + fout->offset,
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fout->length);
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}
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#endif
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ret = usb_submit_urb(urb_out, GFP_ATOMIC);
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if (ret == 0)
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set_bit(index, &line6pcm->active_urb_out);
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else
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dev_err(line6pcm->line6->ifcdev,
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"URB out #%d submission failed (%d)\n", index, ret);
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spin_unlock_irqrestore(&line6pcm->lock_audio_out, flags);
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return 0;
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}
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/*
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Submit all currently available playback URBs.
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*/
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int line6_submit_audio_out_all_urbs(struct snd_line6_pcm *line6pcm)
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{
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int ret, i;
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for (i = 0; i < LINE6_ISO_BUFFERS; ++i) {
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ret = submit_audio_out_urb(line6pcm);
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if (ret < 0)
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return ret;
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}
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return 0;
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}
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/*
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Unlink all currently active playback URBs.
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*/
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void line6_unlink_audio_out_urbs(struct snd_line6_pcm *line6pcm)
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{
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unsigned int i;
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for (i = LINE6_ISO_BUFFERS; i--;) {
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if (test_bit(i, &line6pcm->active_urb_out)) {
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if (!test_and_set_bit(i, &line6pcm->unlink_urb_out)) {
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struct urb *u = line6pcm->urb_audio_out[i];
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usb_unlink_urb(u);
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}
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}
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}
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}
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/*
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Wait until unlinking of all currently active playback URBs has been finished.
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*/
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void line6_wait_clear_audio_out_urbs(struct snd_line6_pcm *line6pcm)
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{
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int timeout = HZ;
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unsigned int i;
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int alive;
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do {
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alive = 0;
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for (i = LINE6_ISO_BUFFERS; i--;) {
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if (test_bit(i, &line6pcm->active_urb_out))
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alive++;
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}
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if (!alive)
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break;
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set_current_state(TASK_UNINTERRUPTIBLE);
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schedule_timeout(1);
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} while (--timeout > 0);
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if (alive)
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snd_printk(KERN_ERR "timeout: still %d active urbs..\n", alive);
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}
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/*
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Unlink all currently active playback URBs, and wait for finishing.
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*/
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void line6_unlink_wait_clear_audio_out_urbs(struct snd_line6_pcm *line6pcm)
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{
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line6_unlink_audio_out_urbs(line6pcm);
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line6_wait_clear_audio_out_urbs(line6pcm);
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}
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void line6_free_playback_buffer(struct snd_line6_pcm *line6pcm)
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{
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kfree(line6pcm->buffer_out);
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line6pcm->buffer_out = NULL;
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}
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/*
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Callback for completed playback URB.
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*/
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static void audio_out_callback(struct urb *urb)
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{
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int i, index, length = 0, shutdown = 0;
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unsigned long flags;
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struct snd_line6_pcm *line6pcm = (struct snd_line6_pcm *)urb->context;
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struct snd_pcm_substream *substream =
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get_substream(line6pcm, SNDRV_PCM_STREAM_PLAYBACK);
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#if USE_CLEAR_BUFFER_WORKAROUND
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memset(urb->transfer_buffer, 0, urb->transfer_buffer_length);
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#endif
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line6pcm->last_frame_out = urb->start_frame;
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/* find index of URB */
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for (index = LINE6_ISO_BUFFERS; index--;)
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if (urb == line6pcm->urb_audio_out[index])
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break;
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if (index < 0)
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return; /* URB has been unlinked asynchronously */
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for (i = LINE6_ISO_PACKETS; i--;)
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length += urb->iso_frame_desc[i].length;
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spin_lock_irqsave(&line6pcm->lock_audio_out, flags);
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if (test_bit(LINE6_INDEX_PCM_ALSA_PLAYBACK_STREAM, &line6pcm->flags)) {
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struct snd_pcm_runtime *runtime = substream->runtime;
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line6pcm->pos_out_done +=
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length / line6pcm->properties->bytes_per_frame;
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if (line6pcm->pos_out_done >= runtime->buffer_size)
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line6pcm->pos_out_done -= runtime->buffer_size;
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}
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clear_bit(index, &line6pcm->active_urb_out);
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for (i = LINE6_ISO_PACKETS; i--;)
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if (urb->iso_frame_desc[i].status == -EXDEV) {
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shutdown = 1;
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break;
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}
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if (test_and_clear_bit(index, &line6pcm->unlink_urb_out))
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shutdown = 1;
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spin_unlock_irqrestore(&line6pcm->lock_audio_out, flags);
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if (!shutdown) {
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submit_audio_out_urb(line6pcm);
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if (test_bit(LINE6_INDEX_PCM_ALSA_PLAYBACK_STREAM, &line6pcm->flags)) {
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line6pcm->bytes_out += length;
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if (line6pcm->bytes_out >= line6pcm->period_out) {
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line6pcm->bytes_out %= line6pcm->period_out;
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snd_pcm_period_elapsed(substream);
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}
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}
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}
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}
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/* open playback callback */
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static int snd_line6_playback_open(struct snd_pcm_substream *substream)
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{
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int err;
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struct snd_pcm_runtime *runtime = substream->runtime;
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struct snd_line6_pcm *line6pcm = snd_pcm_substream_chip(substream);
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err = snd_pcm_hw_constraint_ratdens(runtime, 0, SNDRV_PCM_HW_PARAM_RATE,
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(&line6pcm->
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properties->snd_line6_rates));
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if (err < 0)
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return err;
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runtime->hw = line6pcm->properties->snd_line6_playback_hw;
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return 0;
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}
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/* close playback callback */
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static int snd_line6_playback_close(struct snd_pcm_substream *substream)
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{
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return 0;
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}
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/* hw_params playback callback */
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static int snd_line6_playback_hw_params(struct snd_pcm_substream *substream,
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struct snd_pcm_hw_params *hw_params)
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{
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int ret;
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struct snd_line6_pcm *line6pcm = snd_pcm_substream_chip(substream);
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/* -- Florian Demski [FD] */
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/* don't ask me why, but this fixes the bug on my machine */
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if (line6pcm == NULL) {
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if (substream->pcm == NULL)
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return -ENOMEM;
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if (substream->pcm->private_data == NULL)
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return -ENOMEM;
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substream->private_data = substream->pcm->private_data;
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line6pcm = snd_pcm_substream_chip(substream);
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}
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/* -- [FD] end */
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ret = line6_pcm_acquire(line6pcm, LINE6_BIT_PCM_ALSA_PLAYBACK_BUFFER);
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if (ret < 0)
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return ret;
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ret = snd_pcm_lib_malloc_pages(substream,
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params_buffer_bytes(hw_params));
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if (ret < 0) {
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line6_pcm_release(line6pcm, LINE6_BIT_PCM_ALSA_PLAYBACK_BUFFER);
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return ret;
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}
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|
|
|
line6pcm->period_out = params_period_bytes(hw_params);
|
|
return 0;
|
|
}
|
|
|
|
/* hw_free playback callback */
|
|
static int snd_line6_playback_hw_free(struct snd_pcm_substream *substream)
|
|
{
|
|
struct snd_line6_pcm *line6pcm = snd_pcm_substream_chip(substream);
|
|
line6_pcm_release(line6pcm, LINE6_BIT_PCM_ALSA_PLAYBACK_BUFFER);
|
|
return snd_pcm_lib_free_pages(substream);
|
|
}
|
|
|
|
/* trigger playback callback */
|
|
int snd_line6_playback_trigger(struct snd_line6_pcm *line6pcm, int cmd)
|
|
{
|
|
int err;
|
|
|
|
switch (cmd) {
|
|
case SNDRV_PCM_TRIGGER_START:
|
|
#ifdef CONFIG_PM
|
|
case SNDRV_PCM_TRIGGER_RESUME:
|
|
#endif
|
|
err = line6_pcm_acquire(line6pcm, LINE6_BIT_PCM_ALSA_PLAYBACK_STREAM);
|
|
|
|
if (err < 0)
|
|
return err;
|
|
|
|
break;
|
|
|
|
case SNDRV_PCM_TRIGGER_STOP:
|
|
#ifdef CONFIG_PM
|
|
case SNDRV_PCM_TRIGGER_SUSPEND:
|
|
#endif
|
|
err = line6_pcm_release(line6pcm, LINE6_BIT_PCM_ALSA_PLAYBACK_STREAM);
|
|
|
|
if (err < 0)
|
|
return err;
|
|
|
|
break;
|
|
|
|
case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
|
|
set_bit(LINE6_INDEX_PAUSE_PLAYBACK, &line6pcm->flags);
|
|
break;
|
|
|
|
case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
|
|
clear_bit(LINE6_INDEX_PAUSE_PLAYBACK, &line6pcm->flags);
|
|
break;
|
|
|
|
default:
|
|
return -EINVAL;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/* playback pointer callback */
|
|
static snd_pcm_uframes_t
|
|
snd_line6_playback_pointer(struct snd_pcm_substream *substream)
|
|
{
|
|
struct snd_line6_pcm *line6pcm = snd_pcm_substream_chip(substream);
|
|
return line6pcm->pos_out_done;
|
|
}
|
|
|
|
/* playback operators */
|
|
struct snd_pcm_ops snd_line6_playback_ops = {
|
|
.open = snd_line6_playback_open,
|
|
.close = snd_line6_playback_close,
|
|
.ioctl = snd_pcm_lib_ioctl,
|
|
.hw_params = snd_line6_playback_hw_params,
|
|
.hw_free = snd_line6_playback_hw_free,
|
|
.prepare = snd_line6_prepare,
|
|
.trigger = snd_line6_trigger,
|
|
.pointer = snd_line6_playback_pointer,
|
|
};
|
|
|
|
int line6_create_audio_out_urbs(struct snd_line6_pcm *line6pcm)
|
|
{
|
|
int i;
|
|
|
|
/* create audio URBs and fill in constant values: */
|
|
for (i = 0; i < LINE6_ISO_BUFFERS; ++i) {
|
|
struct urb *urb;
|
|
|
|
/* URB for audio out: */
|
|
urb = line6pcm->urb_audio_out[i] =
|
|
usb_alloc_urb(LINE6_ISO_PACKETS, GFP_KERNEL);
|
|
|
|
if (urb == NULL) {
|
|
dev_err(line6pcm->line6->ifcdev, "Out of memory\n");
|
|
return -ENOMEM;
|
|
}
|
|
|
|
urb->dev = line6pcm->line6->usbdev;
|
|
urb->pipe =
|
|
usb_sndisocpipe(line6pcm->line6->usbdev,
|
|
line6pcm->ep_audio_write &
|
|
USB_ENDPOINT_NUMBER_MASK);
|
|
urb->transfer_flags = URB_ISO_ASAP;
|
|
urb->start_frame = -1;
|
|
urb->number_of_packets = LINE6_ISO_PACKETS;
|
|
urb->interval = LINE6_ISO_INTERVAL;
|
|
urb->error_count = 0;
|
|
urb->complete = audio_out_callback;
|
|
}
|
|
|
|
return 0;
|
|
}
|