--- /dev/null
+/*
+ * Line 6 Linux USB driver
+ *
+ * Copyright (C) 2004-2010 Markus Grabner (grabner@icg.tugraz.at)
+ *
+ * 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, version 2.
+ *
+ */
+
+#include <linux/slab.h>
+#include <sound/core.h>
+#include <sound/pcm.h>
+#include <sound/pcm_params.h>
+
+#include "capture.h"
+#include "driver.h"
+#include "pcm.h"
+#include "playback.h"
+
+/*
+ Software stereo volume control.
+*/
+static void change_volume(struct urb *urb_out, int volume[],
+ int bytes_per_frame)
+{
+ int chn = 0;
+
+ if (volume[0] == 256 && volume[1] == 256)
+ return; /* maximum volume - no change */
+
+ if (bytes_per_frame == 4) {
+ __le16 *p, *buf_end;
+
+ p = (__le16 *)urb_out->transfer_buffer;
+ buf_end = p + urb_out->transfer_buffer_length / sizeof(*p);
+
+ for (; p < buf_end; ++p) {
+ short pv = le16_to_cpu(*p);
+ int val = (pv * volume[chn & 1]) >> 8;
+ pv = clamp(val, -0x8000, 0x7fff);
+ *p = cpu_to_le16(pv);
+ ++chn;
+ }
+ } else if (bytes_per_frame == 6) {
+ unsigned char *p, *buf_end;
+
+ p = (unsigned char *)urb_out->transfer_buffer;
+ buf_end = p + urb_out->transfer_buffer_length;
+
+ for (; p < buf_end; p += 3) {
+ int val;
+
+ val = p[0] + (p[1] << 8) + ((signed char)p[2] << 16);
+ val = (val * volume[chn & 1]) >> 8;
+ val = clamp(val, -0x800000, 0x7fffff);
+ p[0] = val;
+ p[1] = val >> 8;
+ p[2] = val >> 16;
+ ++chn;
+ }
+ }
+}
+
+/*
+ Create signal for impulse response test.
+*/
+static void create_impulse_test_signal(struct snd_line6_pcm *line6pcm,
+ struct urb *urb_out, int bytes_per_frame)
+{
+ int frames = urb_out->transfer_buffer_length / bytes_per_frame;
+
+ if (bytes_per_frame == 4) {
+ int i;
+ short *pi = (short *)line6pcm->prev_fbuf;
+ short *po = (short *)urb_out->transfer_buffer;
+
+ for (i = 0; i < frames; ++i) {
+ po[0] = pi[0];
+ po[1] = 0;
+ pi += 2;
+ po += 2;
+ }
+ } else if (bytes_per_frame == 6) {
+ int i, j;
+ unsigned char *pi = line6pcm->prev_fbuf;
+ unsigned char *po = urb_out->transfer_buffer;
+
+ for (i = 0; i < frames; ++i) {
+ for (j = 0; j < bytes_per_frame / 2; ++j)
+ po[j] = pi[j];
+
+ for (; j < bytes_per_frame; ++j)
+ po[j] = 0;
+
+ pi += bytes_per_frame;
+ po += bytes_per_frame;
+ }
+ }
+ if (--line6pcm->impulse_count <= 0) {
+ ((unsigned char *)(urb_out->transfer_buffer))[bytes_per_frame -
+ 1] =
+ line6pcm->impulse_volume;
+ line6pcm->impulse_count = line6pcm->impulse_period;
+ }
+}
+
+/*
+ Add signal to buffer for software monitoring.
+*/
+static void add_monitor_signal(struct urb *urb_out, unsigned char *signal,
+ int volume, int bytes_per_frame)
+{
+ if (volume == 0)
+ return; /* zero volume - no change */
+
+ if (bytes_per_frame == 4) {
+ __le16 *pi, *po, *buf_end;
+
+ pi = (__le16 *)signal;
+ po = (__le16 *)urb_out->transfer_buffer;
+ buf_end = po + urb_out->transfer_buffer_length / sizeof(*po);
+
+ for (; po < buf_end; ++pi, ++po) {
+ short pov = le16_to_cpu(*po);
+ short piv = le16_to_cpu(*pi);
+ int val = pov + ((piv * volume) >> 8);
+ pov = clamp(val, -0x8000, 0x7fff);
+ *po = cpu_to_le16(pov);
+ }
+ }
+
+ /*
+ We don't need to handle devices with 6 bytes per frame here
+ since they all support hardware monitoring.
+ */
+}
+
+/*
+ Find a free URB, prepare audio data, and submit URB.
+ must be called in line6pcm->out.lock context
+*/
+static int submit_audio_out_urb(struct snd_line6_pcm *line6pcm)
+{
+ int index;
+ int i, urb_size, urb_frames;
+ int ret;
+ const int bytes_per_frame = line6pcm->properties->bytes_per_frame;
+ const int frame_increment =
+ line6pcm->properties->rates.rats[0].num_min;
+ const int frame_factor =
+ line6pcm->properties->rates.rats[0].den *
+ (USB_INTERVALS_PER_SECOND / LINE6_ISO_INTERVAL);
+ struct urb *urb_out;
+
+ index =
+ find_first_zero_bit(&line6pcm->out.active_urbs, LINE6_ISO_BUFFERS);
+
+ if (index < 0 || index >= LINE6_ISO_BUFFERS) {
+ dev_err(line6pcm->line6->ifcdev, "no free URB found\n");
+ return -EINVAL;
+ }
+
+ urb_out = line6pcm->out.urbs[index];
+ urb_size = 0;
+
+ for (i = 0; i < LINE6_ISO_PACKETS; ++i) {
+ /* compute frame size for given sampling rate */
+ int fsize = 0;
+ struct usb_iso_packet_descriptor *fout =
+ &urb_out->iso_frame_desc[i];
+
+ fsize = line6pcm->prev_fsize;
+ if (fsize == 0) {
+ int n;
+
+ line6pcm->out.count += frame_increment;
+ n = line6pcm->out.count / frame_factor;
+ line6pcm->out.count -= n * frame_factor;
+ fsize = n * bytes_per_frame;
+ }
+
+ fout->offset = urb_size;
+ fout->length = fsize;
+ urb_size += fsize;
+ }
+
+ if (urb_size == 0) {
+ /* can't determine URB size */
+ dev_err(line6pcm->line6->ifcdev, "driver bug: urb_size = 0\n");
+ return -EINVAL;
+ }
+
+ urb_frames = urb_size / bytes_per_frame;
+ urb_out->transfer_buffer =
+ line6pcm->out.buffer +
+ index * LINE6_ISO_PACKETS * line6pcm->max_packet_size;
+ urb_out->transfer_buffer_length = urb_size;
+ urb_out->context = line6pcm;
+
+ if (test_bit(LINE6_STREAM_PCM, &line6pcm->out.running) &&
+ !test_bit(LINE6_FLAG_PAUSE_PLAYBACK, &line6pcm->flags)) {
+ struct snd_pcm_runtime *runtime =
+ get_substream(line6pcm, SNDRV_PCM_STREAM_PLAYBACK)->runtime;
+
+ if (line6pcm->out.pos + urb_frames > runtime->buffer_size) {
+ /*
+ The transferred area goes over buffer boundary,
+ copy the data to the temp buffer.
+ */
+ int len;
+
+ len = runtime->buffer_size - line6pcm->out.pos;
+
+ if (len > 0) {
+ memcpy(urb_out->transfer_buffer,
+ runtime->dma_area +
+ line6pcm->out.pos * bytes_per_frame,
+ len * bytes_per_frame);
+ memcpy(urb_out->transfer_buffer +
+ len * bytes_per_frame, runtime->dma_area,
+ (urb_frames - len) * bytes_per_frame);
+ } else
+ dev_err(line6pcm->line6->ifcdev, "driver bug: len = %d\n",
+ len);
+ } else {
+ memcpy(urb_out->transfer_buffer,
+ runtime->dma_area +
+ line6pcm->out.pos * bytes_per_frame,
+ urb_out->transfer_buffer_length);
+ }
+
+ line6pcm->out.pos += urb_frames;
+ if (line6pcm->out.pos >= runtime->buffer_size)
+ line6pcm->out.pos -= runtime->buffer_size;
+
+ change_volume(urb_out, line6pcm->volume_playback,
+ bytes_per_frame);
+ } else {
+ memset(urb_out->transfer_buffer, 0,
+ urb_out->transfer_buffer_length);
+ }
+
+ spin_lock_nested(&line6pcm->in.lock, SINGLE_DEPTH_NESTING);
+ if (line6pcm->prev_fbuf) {
+ if (test_bit(LINE6_STREAM_IMPULSE, &line6pcm->out.running)) {
+ create_impulse_test_signal(line6pcm, urb_out,
+ bytes_per_frame);
+ if (test_bit(LINE6_STREAM_PCM, &line6pcm->in.running)) {
+ line6_capture_copy(line6pcm,
+ urb_out->transfer_buffer,
+ urb_out->
+ transfer_buffer_length);
+ line6_capture_check_period(line6pcm,
+ urb_out->transfer_buffer_length);
+ }
+ } else {
+ if (!(line6pcm->line6->properties->capabilities & LINE6_CAP_HWMON)
+ && line6pcm->out.running && line6pcm->in.running)
+ add_monitor_signal(urb_out, line6pcm->prev_fbuf,
+ line6pcm->volume_monitor,
+ bytes_per_frame);
+ }
+ line6pcm->prev_fbuf = NULL;
+ line6pcm->prev_fsize = 0;
+ }
+ spin_unlock(&line6pcm->in.lock);
+
+ ret = usb_submit_urb(urb_out, GFP_ATOMIC);
+
+ if (ret == 0)
+ set_bit(index, &line6pcm->out.active_urbs);
+ else
+ dev_err(line6pcm->line6->ifcdev,
+ "URB out #%d submission failed (%d)\n", index, ret);
+
+ return 0;
+}
+
+/*
+ Submit all currently available playback URBs.
+ must be called in line6pcm->out.lock context
+ */
+int line6_submit_audio_out_all_urbs(struct snd_line6_pcm *line6pcm)
+{
+ int ret = 0, i;
+
+ for (i = 0; i < LINE6_ISO_BUFFERS; ++i) {
+ ret = submit_audio_out_urb(line6pcm);
+ if (ret < 0)
+ break;
+ }
+
+ return ret;
+}
+
+/*
+ Callback for completed playback URB.
+*/
+static void audio_out_callback(struct urb *urb)
+{
+ int i, index, length = 0, shutdown = 0;
+ unsigned long flags;
+ struct snd_line6_pcm *line6pcm = (struct snd_line6_pcm *)urb->context;
+ struct snd_pcm_substream *substream =
+ get_substream(line6pcm, SNDRV_PCM_STREAM_PLAYBACK);
+
+#if USE_CLEAR_BUFFER_WORKAROUND
+ memset(urb->transfer_buffer, 0, urb->transfer_buffer_length);
+#endif
+
+ line6pcm->out.last_frame = urb->start_frame;
+
+ /* find index of URB */
+ for (index = 0; index < LINE6_ISO_BUFFERS; index++)
+ if (urb == line6pcm->out.urbs[index])
+ break;
+
+ if (index >= LINE6_ISO_BUFFERS)
+ return; /* URB has been unlinked asynchronously */
+
+ for (i = 0; i < LINE6_ISO_PACKETS; i++)
+ length += urb->iso_frame_desc[i].length;
+
+ spin_lock_irqsave(&line6pcm->out.lock, flags);
+
+ if (test_bit(LINE6_STREAM_PCM, &line6pcm->out.running)) {
+ struct snd_pcm_runtime *runtime = substream->runtime;
+
+ line6pcm->out.pos_done +=
+ length / line6pcm->properties->bytes_per_frame;
+
+ if (line6pcm->out.pos_done >= runtime->buffer_size)
+ line6pcm->out.pos_done -= runtime->buffer_size;
+ }
+
+ clear_bit(index, &line6pcm->out.active_urbs);
+
+ for (i = 0; i < LINE6_ISO_PACKETS; i++)
+ if (urb->iso_frame_desc[i].status == -EXDEV) {
+ shutdown = 1;
+ break;
+ }
+
+ if (test_and_clear_bit(index, &line6pcm->out.unlink_urbs))
+ shutdown = 1;
+
+ if (!shutdown) {
+ submit_audio_out_urb(line6pcm);
+
+ if (test_bit(LINE6_STREAM_PCM, &line6pcm->out.running)) {
+ line6pcm->out.bytes += length;
+ if (line6pcm->out.bytes >= line6pcm->out.period) {
+ line6pcm->out.bytes %= line6pcm->out.period;
+ spin_unlock(&line6pcm->out.lock);
+ snd_pcm_period_elapsed(substream);
+ spin_lock(&line6pcm->out.lock);
+ }
+ }
+ }
+ spin_unlock_irqrestore(&line6pcm->out.lock, flags);
+}
+
+/* open playback callback */
+static int snd_line6_playback_open(struct snd_pcm_substream *substream)
+{
+ int err;
+ struct snd_pcm_runtime *runtime = substream->runtime;
+ struct snd_line6_pcm *line6pcm = snd_pcm_substream_chip(substream);
+
+ err = snd_pcm_hw_constraint_ratdens(runtime, 0, SNDRV_PCM_HW_PARAM_RATE,
+ &line6pcm->properties->rates);
+ if (err < 0)
+ return err;
+
+ runtime->hw = line6pcm->properties->playback_hw;
+ return 0;
+}
+
+/* close playback callback */
+static int snd_line6_playback_close(struct snd_pcm_substream *substream)
+{
+ return 0;
+}
+
+/* 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_hw_params,
+ .hw_free = snd_line6_hw_free,
+ .prepare = snd_line6_prepare,
+ .trigger = snd_line6_trigger,
+ .pointer = snd_line6_pointer,
+};
+
+int line6_create_audio_out_urbs(struct snd_line6_pcm *line6pcm)
+{
+ struct usb_line6 *line6 = line6pcm->line6;
+ 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->out.urbs[i] =
+ usb_alloc_urb(LINE6_ISO_PACKETS, GFP_KERNEL);
+
+ if (urb == NULL)
+ return -ENOMEM;
+
+ urb->dev = line6->usbdev;
+ urb->pipe =
+ usb_sndisocpipe(line6->usbdev,
+ line6->properties->ep_audio_w &
+ 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;
+}
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