sound/usb/line6/capture.c

   1 /*
   2  * Line 6 Linux USB driver
   3  *
   4  * Copyright (C) 2004-2010 Markus Grabner (grabner@icg.tugraz.at)
   5  *
   6  *      This program is free software; you can redistribute it and/or
   7  *      modify it under the terms of the GNU General Public License as
   8  *      published by the Free Software Foundation, version 2.
   9  *
  10  */
  11
  12 #include <linux/slab.h>
  13 #include <sound/core.h>
  14 #include <sound/pcm.h>
  15 #include <sound/pcm_params.h>
  16
  17 #include "capture.h"
  18 #include "driver.h"
  19 #include "pcm.h"
  20
  21 /*
  22         Find a free URB and submit it.
  23         must be called in line6pcm->in.lock context
  24 */
  25 static int submit_audio_in_urb(struct snd_line6_pcm *line6pcm)
  26 {
  27         int index;
  28         int i, urb_size;
  29         int ret;
  30         struct urb *urb_in;
  31
  32         index = find_first_zero_bit(&line6pcm->in.active_urbs,
  33                                     line6pcm->line6->iso_buffers);
  34
  35         if (index < 0 || index >= line6pcm->line6->iso_buffers) {
  36                 dev_err(line6pcm->line6->ifcdev, "no free URB found\n");
  37                 return -EINVAL;
  38         }
  39
  40         urb_in = line6pcm->in.urbs[index];
  41         urb_size = 0;
  42
  43         for (i = 0; i < LINE6_ISO_PACKETS; ++i) {
  44                 struct usb_iso_packet_descriptor *fin =
  45                     &urb_in->iso_frame_desc[i];
  46                 fin->offset = urb_size;
  47                 fin->length = line6pcm->max_packet_size_in;
  48                 urb_size += line6pcm->max_packet_size_in;
  49         }
  50
  51         urb_in->transfer_buffer =
  52             line6pcm->in.buffer +
  53             index * LINE6_ISO_PACKETS * line6pcm->max_packet_size_in;
  54         urb_in->transfer_buffer_length = urb_size;
  55         urb_in->context = line6pcm;
  56
  57         ret = usb_submit_urb(urb_in, GFP_ATOMIC);
  58
  59         if (ret == 0)
  60                 set_bit(index, &line6pcm->in.active_urbs);
  61         else
  62                 dev_err(line6pcm->line6->ifcdev,
  63                         "URB in #%d submission failed (%d)\n", index, ret);
  64
  65         return 0;
  66 }
  67
  68 /*
  69         Submit all currently available capture URBs.
  70         must be called in line6pcm->in.lock context
  71 */
  72 int line6_submit_audio_in_all_urbs(struct snd_line6_pcm *line6pcm)
  73 {
  74         int ret = 0, i;
  75
  76         for (i = 0; i < line6pcm->line6->iso_buffers; ++i) {
  77                 ret = submit_audio_in_urb(line6pcm);
  78                 if (ret < 0)
  79                         break;
  80         }
  81
  82         return ret;
  83 }
  84
  85 /*
  86         Copy data into ALSA capture buffer.
  87 */
  88 void line6_capture_copy(struct snd_line6_pcm *line6pcm, char *fbuf, int fsize)
  89 {
  90         struct snd_pcm_substream *substream =
  91             get_substream(line6pcm, SNDRV_PCM_STREAM_CAPTURE);
  92         struct snd_pcm_runtime *runtime = substream->runtime;
  93         const int bytes_per_frame =
  94                 line6pcm->properties->bytes_per_channel *
  95                 line6pcm->properties->capture_hw.channels_max;
  96         int frames = fsize / bytes_per_frame;
  97
  98         if (runtime == NULL)
  99                 return;
 100
 101         if (line6pcm->in.pos_done + frames > runtime->buffer_size) {
 102                 /*
 103                    The transferred area goes over buffer boundary,
 104                    copy two separate chunks.
 105                  */
 106                 int len;
 107
 108                 len = runtime->buffer_size - line6pcm->in.pos_done;
 109
 110                 if (len > 0) {
 111                         memcpy(runtime->dma_area +
 112                                line6pcm->in.pos_done * bytes_per_frame, fbuf,
 113                                len * bytes_per_frame);
 114                         memcpy(runtime->dma_area, fbuf + len * bytes_per_frame,
 115                                (frames - len) * bytes_per_frame);
 116                 } else {
 117                         /* this is somewhat paranoid */
 118                         dev_err(line6pcm->line6->ifcdev,
 119                                 "driver bug: len = %d\n", len);
 120                 }
 121         } else {
 122                 /* copy single chunk */
 123                 memcpy(runtime->dma_area +
 124                        line6pcm->in.pos_done * bytes_per_frame, fbuf, fsize);
 125         }
 126
 127         line6pcm->in.pos_done += frames;
 128         if (line6pcm->in.pos_done >= runtime->buffer_size)
 129                 line6pcm->in.pos_done -= runtime->buffer_size;
 130 }
 131
 132 void line6_capture_check_period(struct snd_line6_pcm *line6pcm, int length)
 133 {
 134         struct snd_pcm_substream *substream =
 135             get_substream(line6pcm, SNDRV_PCM_STREAM_CAPTURE);
 136
 137         line6pcm->in.bytes += length;
 138         if (line6pcm->in.bytes >= line6pcm->in.period) {
 139                 line6pcm->in.bytes %= line6pcm->in.period;
 140                 spin_unlock(&line6pcm->in.lock);
 141                 snd_pcm_period_elapsed(substream);
 142                 spin_lock(&line6pcm->in.lock);
 143         }
 144 }
 145
 146 /*
 147  * Callback for completed capture URB.
 148  */
 149 static void audio_in_callback(struct urb *urb)
 150 {
 151         int i, index, length = 0, shutdown = 0;
 152         unsigned long flags;
 153
 154         struct snd_line6_pcm *line6pcm = (struct snd_line6_pcm *)urb->context;
 155
 156         line6pcm->in.last_frame = urb->start_frame;
 157
 158         /* find index of URB */
 159         for (index = 0; index < line6pcm->line6->iso_buffers; ++index)
 160                 if (urb == line6pcm->in.urbs[index])
 161                         break;
 162
 163         spin_lock_irqsave(&line6pcm->in.lock, flags);
 164
 165         for (i = 0; i < LINE6_ISO_PACKETS; ++i) {
 166                 char *fbuf;
 167                 int fsize;
 168                 struct usb_iso_packet_descriptor *fin = &urb->iso_frame_desc[i];
 169
 170                 if (fin->status == -EXDEV) {
 171                         shutdown = 1;
 172                         break;
 173                 }
 174
 175                 fbuf = urb->transfer_buffer + fin->offset;
 176                 fsize = fin->actual_length;
 177
 178                 if (fsize > line6pcm->max_packet_size_in) {
 179                         dev_err(line6pcm->line6->ifcdev,
 180                                 "driver and/or device bug: packet too large (%d > %d)\n",
 181                                 fsize, line6pcm->max_packet_size_in);
 182                 }
 183
 184                 length += fsize;
 185
 186                 BUILD_BUG_ON_MSG(LINE6_ISO_PACKETS != 1,
 187                         "The following code assumes LINE6_ISO_PACKETS == 1");
 188                 /* TODO:
 189                  * Also, if iso_buffers != 2, the prev frame is almost random at
 190                  * playback side.
 191                  * This needs to be redesigned. It should be "stable", but we may
 192                  * experience sync problems on such high-speed configs.
 193                  */
 194
 195                 line6pcm->prev_fbuf = fbuf;
 196                 line6pcm->prev_fsize = fsize /
 197                         (line6pcm->properties->bytes_per_channel *
 198                         line6pcm->properties->capture_hw.channels_max);
 199
 200                 if (!test_bit(LINE6_STREAM_IMPULSE, &line6pcm->in.running) &&
 201                     test_bit(LINE6_STREAM_PCM, &line6pcm->in.running) &&
 202                     fsize > 0)
 203                         line6_capture_copy(line6pcm, fbuf, fsize);
 204         }
 205
 206         clear_bit(index, &line6pcm->in.active_urbs);
 207
 208         if (test_and_clear_bit(index, &line6pcm->in.unlink_urbs))
 209                 shutdown = 1;
 210
 211         if (!shutdown) {
 212                 submit_audio_in_urb(line6pcm);
 213
 214                 if (!test_bit(LINE6_STREAM_IMPULSE, &line6pcm->in.running) &&
 215                     test_bit(LINE6_STREAM_PCM, &line6pcm->in.running))
 216                         line6_capture_check_period(line6pcm, length);
 217         }
 218
 219         spin_unlock_irqrestore(&line6pcm->in.lock, flags);
 220 }
 221
 222 /* open capture callback */
 223 static int snd_line6_capture_open(struct snd_pcm_substream *substream)
 224 {
 225         int err;
 226         struct snd_pcm_runtime *runtime = substream->runtime;
 227         struct snd_line6_pcm *line6pcm = snd_pcm_substream_chip(substream);
 228
 229         err = snd_pcm_hw_constraint_ratdens(runtime, 0,
 230                                             SNDRV_PCM_HW_PARAM_RATE,
 231                                             &line6pcm->properties->rates);
 232         if (err < 0)
 233                 return err;
 234
 235         line6_pcm_acquire(line6pcm, LINE6_STREAM_CAPTURE_HELPER, false);
 236
 237         runtime->hw = line6pcm->properties->capture_hw;
 238         return 0;
 239 }
 240
 241 /* close capture callback */
 242 static int snd_line6_capture_close(struct snd_pcm_substream *substream)
 243 {
 244         struct snd_line6_pcm *line6pcm = snd_pcm_substream_chip(substream);
 245
 246         line6_pcm_release(line6pcm, LINE6_STREAM_CAPTURE_HELPER);
 247         return 0;
 248 }
 249
 250 /* capture operators */
 251 struct snd_pcm_ops snd_line6_capture_ops = {
 252         .open = snd_line6_capture_open,
 253         .close = snd_line6_capture_close,
 254         .ioctl = snd_pcm_lib_ioctl,
 255         .hw_params = snd_line6_hw_params,
 256         .hw_free = snd_line6_hw_free,
 257         .prepare = snd_line6_prepare,
 258         .trigger = snd_line6_trigger,
 259         .pointer = snd_line6_pointer,
 260 };
 261
 262 int line6_create_audio_in_urbs(struct snd_line6_pcm *line6pcm)
 263 {
 264         struct usb_line6 *line6 = line6pcm->line6;
 265         int i;
 266
 267         line6pcm->in.urbs = kzalloc(
 268                 sizeof(struct urb *) * line6->iso_buffers, GFP_KERNEL);
 269         if (line6pcm->in.urbs == NULL)
 270                 return -ENOMEM;
 271
 272         /* create audio URBs and fill in constant values: */
 273         for (i = 0; i < line6->iso_buffers; ++i) {
 274                 struct urb *urb;
 275
 276                 /* URB for audio in: */
 277                 urb = line6pcm->in.urbs[i] =
 278                     usb_alloc_urb(LINE6_ISO_PACKETS, GFP_KERNEL);
 279
 280                 if (urb == NULL)
 281                         return -ENOMEM;
 282
 283                 urb->dev = line6->usbdev;
 284                 urb->pipe =
 285                     usb_rcvisocpipe(line6->usbdev,
 286                                     line6->properties->ep_audio_r &
 287                                     USB_ENDPOINT_NUMBER_MASK);
 288                 urb->transfer_flags = URB_ISO_ASAP;
 289                 urb->start_frame = -1;
 290                 urb->number_of_packets = LINE6_ISO_PACKETS;
 291                 urb->interval = LINE6_ISO_INTERVAL;
 292                 urb->error_count = 0;
 293                 urb->complete = audio_in_callback;
 294         }
 295
 296         return 0;
 297 }