usb/line6/playback.c

0001 // SPDX-License-Identifier: GPL-2.0-only
0002 /*
0003  * Line 6 Linux USB driver
0004  *
0005  * Copyright (C) 2004-2010 Markus Grabner (grabner@icg.tugraz.at)
0006  */
0007
0008 #include <linux/slab.h>
0009 #include <sound/core.h>
0010 #include <sound/pcm.h>
0011 #include <sound/pcm_params.h>
0012
0013 #include "capture.h"
0014 #include "driver.h"
0015 #include "pcm.h"
0016 #include "playback.h"
0017
0018 /*
0019     Software stereo volume control.
0020 */
0021 static void change_volume(struct urb *urb_out, int volume[],
0022               int bytes_per_frame)
0023 {
0024     int chn = 0;
0025
0026     if (volume[0] == 256 && volume[1] == 256)
0027         return;     /* maximum volume - no change */
0028
0029     if (bytes_per_frame == 4) {
0030         __le16 *p, *buf_end;
0031
0032         p = (__le16 *)urb_out->transfer_buffer;
0033         buf_end = p + urb_out->transfer_buffer_length / sizeof(*p);
0034
0035         for (; p < buf_end; ++p) {
0036             short pv = le16_to_cpu(*p);
0037             int val = (pv * volume[chn & 1]) >> 8;
0038             pv = clamp(val, -0x8000, 0x7fff);
0039             *p = cpu_to_le16(pv);
0040             ++chn;
0041         }
0042     } else if (bytes_per_frame == 6) {
0043         unsigned char *p, *buf_end;
0044
0045         p = (unsigned char *)urb_out->transfer_buffer;
0046         buf_end = p + urb_out->transfer_buffer_length;
0047
0048         for (; p < buf_end; p += 3) {
0049             int val;
0050
0051             val = p[0] + (p[1] << 8) + ((signed char)p[2] << 16);
0052             val = (val * volume[chn & 1]) >> 8;
0053             val = clamp(val, -0x800000, 0x7fffff);
0054             p[0] = val;
0055             p[1] = val >> 8;
0056             p[2] = val >> 16;
0057             ++chn;
0058         }
0059     }
0060 }
0061
0062 /*
0063     Create signal for impulse response test.
0064 */
0065 static void create_impulse_test_signal(struct snd_line6_pcm *line6pcm,
0066                        struct urb *urb_out, int bytes_per_frame)
0067 {
0068     int frames = urb_out->transfer_buffer_length / bytes_per_frame;
0069
0070     if (bytes_per_frame == 4) {
0071         int i;
0072         short *pi = (short *)line6pcm->prev_fbuf;
0073         short *po = (short *)urb_out->transfer_buffer;
0074
0075         for (i = 0; i < frames; ++i) {
0076             po[0] = pi[0];
0077             po[1] = 0;
0078             pi += 2;
0079             po += 2;
0080         }
0081     } else if (bytes_per_frame == 6) {
0082         int i, j;
0083         unsigned char *pi = line6pcm->prev_fbuf;
0084         unsigned char *po = urb_out->transfer_buffer;
0085
0086         for (i = 0; i < frames; ++i) {
0087             for (j = 0; j < bytes_per_frame / 2; ++j)
0088                 po[j] = pi[j];
0089
0090             for (; j < bytes_per_frame; ++j)
0091                 po[j] = 0;
0092
0093             pi += bytes_per_frame;
0094             po += bytes_per_frame;
0095         }
0096     }
0097     if (--line6pcm->impulse_count <= 0) {
0098         ((unsigned char *)(urb_out->transfer_buffer))[bytes_per_frame -
0099                                   1] =
0100             line6pcm->impulse_volume;
0101         line6pcm->impulse_count = line6pcm->impulse_period;
0102     }
0103 }
0104
0105 /*
0106     Add signal to buffer for software monitoring.
0107 */
0108 static void add_monitor_signal(struct urb *urb_out, unsigned char *signal,
0109                    int volume, int bytes_per_frame)
0110 {
0111     if (volume == 0)
0112         return;     /* zero volume - no change */
0113
0114     if (bytes_per_frame == 4) {
0115         __le16 *pi, *po, *buf_end;
0116
0117         pi = (__le16 *)signal;
0118         po = (__le16 *)urb_out->transfer_buffer;
0119         buf_end = po + urb_out->transfer_buffer_length / sizeof(*po);
0120
0121         for (; po < buf_end; ++pi, ++po) {
0122             short pov = le16_to_cpu(*po);
0123             short piv = le16_to_cpu(*pi);
0124             int val = pov + ((piv * volume) >> 8);
0125             pov = clamp(val, -0x8000, 0x7fff);
0126             *po = cpu_to_le16(pov);
0127         }
0128     }
0129
0130     /*
0131        We don't need to handle devices with 6 bytes per frame here
0132        since they all support hardware monitoring.
0133      */
0134 }
0135
0136 /*
0137     Find a free URB, prepare audio data, and submit URB.
0138     must be called in line6pcm->out.lock context
0139 */
0140 static int submit_audio_out_urb(struct snd_line6_pcm *line6pcm)
0141 {
0142     int index;
0143     int i, urb_size, urb_frames;
0144     int ret;
0145     const int bytes_per_frame =
0146         line6pcm->properties->bytes_per_channel *
0147         line6pcm->properties->playback_hw.channels_max;
0148     const int frame_increment =
0149         line6pcm->properties->rates.rats[0].num_min;
0150     const int frame_factor =
0151         line6pcm->properties->rates.rats[0].den *
0152         (line6pcm->line6->intervals_per_second / LINE6_ISO_INTERVAL);
0153     struct urb *urb_out;
0154
0155     index = find_first_zero_bit(&line6pcm->out.active_urbs,
0156                     line6pcm->line6->iso_buffers);
0157
0158     if (index < 0 || index >= line6pcm->line6->iso_buffers) {
0159         dev_err(line6pcm->line6->ifcdev, "no free URB found\n");
0160         return -EINVAL;
0161     }
0162
0163     urb_out = line6pcm->out.urbs[index];
0164     urb_size = 0;
0165
0166     /* TODO: this may not work for LINE6_ISO_PACKETS != 1 */
0167     for (i = 0; i < LINE6_ISO_PACKETS; ++i) {
0168         /* compute frame size for given sampling rate */
0169         int fsize = 0;
0170         struct usb_iso_packet_descriptor *fout =
0171             &urb_out->iso_frame_desc[i];
0172
0173         fsize = line6pcm->prev_fsize;
0174         if (fsize == 0) {
0175             int n;
0176
0177             line6pcm->out.count += frame_increment;
0178             n = line6pcm->out.count / frame_factor;
0179             line6pcm->out.count -= n * frame_factor;
0180             fsize = n;
0181         }
0182
0183         fsize *= bytes_per_frame;
0184
0185         fout->offset = urb_size;
0186         fout->length = fsize;
0187         urb_size += fsize;
0188     }
0189
0190     if (urb_size == 0) {
0191         /* can't determine URB size */
0192         dev_err(line6pcm->line6->ifcdev, "driver bug: urb_size = 0\n");
0193         return -EINVAL;
0194     }
0195
0196     urb_frames = urb_size / bytes_per_frame;
0197     urb_out->transfer_buffer =
0198         line6pcm->out.buffer +
0199         index * LINE6_ISO_PACKETS * line6pcm->max_packet_size_out;
0200     urb_out->transfer_buffer_length = urb_size;
0201     urb_out->context = line6pcm;
0202
0203     if (test_bit(LINE6_STREAM_PCM, &line6pcm->out.running) &&
0204         !test_bit(LINE6_FLAG_PAUSE_PLAYBACK, &line6pcm->flags)) {
0205         struct snd_pcm_runtime *runtime =
0206             get_substream(line6pcm, SNDRV_PCM_STREAM_PLAYBACK)->runtime;
0207
0208         if (line6pcm->out.pos + urb_frames > runtime->buffer_size) {
0209             /*
0210                The transferred area goes over buffer boundary,
0211                copy the data to the temp buffer.
0212              */
0213             int len;
0214
0215             len = runtime->buffer_size - line6pcm->out.pos;
0216
0217             if (len > 0) {
0218                 memcpy(urb_out->transfer_buffer,
0219                        runtime->dma_area +
0220                        line6pcm->out.pos * bytes_per_frame,
0221                        len * bytes_per_frame);
0222                 memcpy(urb_out->transfer_buffer +
0223                        len * bytes_per_frame, runtime->dma_area,
0224                        (urb_frames - len) * bytes_per_frame);
0225             } else
0226                 dev_err(line6pcm->line6->ifcdev, "driver bug: len = %d\n",
0227                     len);
0228         } else {
0229             memcpy(urb_out->transfer_buffer,
0230                    runtime->dma_area +
0231                    line6pcm->out.pos * bytes_per_frame,
0232                    urb_out->transfer_buffer_length);
0233         }
0234
0235         line6pcm->out.pos += urb_frames;
0236         if (line6pcm->out.pos >= runtime->buffer_size)
0237             line6pcm->out.pos -= runtime->buffer_size;
0238
0239         change_volume(urb_out, line6pcm->volume_playback,
0240                   bytes_per_frame);
0241     } else {
0242         memset(urb_out->transfer_buffer, 0,
0243                urb_out->transfer_buffer_length);
0244     }
0245
0246     spin_lock_nested(&line6pcm->in.lock, SINGLE_DEPTH_NESTING);
0247     if (line6pcm->prev_fbuf) {
0248         if (test_bit(LINE6_STREAM_IMPULSE, &line6pcm->out.running)) {
0249             create_impulse_test_signal(line6pcm, urb_out,
0250                            bytes_per_frame);
0251             if (test_bit(LINE6_STREAM_PCM, &line6pcm->in.running)) {
0252                 line6_capture_copy(line6pcm,
0253                            urb_out->transfer_buffer,
0254                            urb_out->
0255                            transfer_buffer_length);
0256                 line6_capture_check_period(line6pcm,
0257                     urb_out->transfer_buffer_length);
0258             }
0259         } else {
0260             if (!(line6pcm->line6->properties->capabilities & LINE6_CAP_HWMON)
0261                 && line6pcm->out.running && line6pcm->in.running)
0262                 add_monitor_signal(urb_out, line6pcm->prev_fbuf,
0263                            line6pcm->volume_monitor,
0264                            bytes_per_frame);
0265         }
0266         line6pcm->prev_fbuf = NULL;
0267         line6pcm->prev_fsize = 0;
0268     }
0269     spin_unlock(&line6pcm->in.lock);
0270
0271     ret = usb_submit_urb(urb_out, GFP_ATOMIC);
0272
0273     if (ret == 0)
0274         set_bit(index, &line6pcm->out.active_urbs);
0275     else
0276         dev_err(line6pcm->line6->ifcdev,
0277             "URB out #%d submission failed (%d)\n", index, ret);
0278
0279     return 0;
0280 }
0281
0282 /*
0283     Submit all currently available playback URBs.
0284     must be called in line6pcm->out.lock context
0285  */
0286 int line6_submit_audio_out_all_urbs(struct snd_line6_pcm *line6pcm)
0287 {
0288     int ret = 0, i;
0289
0290     for (i = 0; i < line6pcm->line6->iso_buffers; ++i) {
0291         ret = submit_audio_out_urb(line6pcm);
0292         if (ret < 0)
0293             break;
0294     }
0295
0296     return ret;
0297 }
0298
0299 /*
0300     Callback for completed playback URB.
0301 */
0302 static void audio_out_callback(struct urb *urb)
0303 {
0304     int i, index, length = 0, shutdown = 0;
0305     unsigned long flags;
0306     struct snd_line6_pcm *line6pcm = (struct snd_line6_pcm *)urb->context;
0307     struct snd_pcm_substream *substream =
0308         get_substream(line6pcm, SNDRV_PCM_STREAM_PLAYBACK);
0309     const int bytes_per_frame =
0310         line6pcm->properties->bytes_per_channel *
0311         line6pcm->properties->playback_hw.channels_max;
0312
0313 #if USE_CLEAR_BUFFER_WORKAROUND
0314     memset(urb->transfer_buffer, 0, urb->transfer_buffer_length);
0315 #endif
0316
0317     line6pcm->out.last_frame = urb->start_frame;
0318
0319     /* find index of URB */
0320     for (index = 0; index < line6pcm->line6->iso_buffers; index++)
0321         if (urb == line6pcm->out.urbs[index])
0322             break;
0323
0324     if (index >= line6pcm->line6->iso_buffers)
0325         return;     /* URB has been unlinked asynchronously */
0326
0327     for (i = 0; i < LINE6_ISO_PACKETS; i++)
0328         length += urb->iso_frame_desc[i].length;
0329
0330     spin_lock_irqsave(&line6pcm->out.lock, flags);
0331
0332     if (test_bit(LINE6_STREAM_PCM, &line6pcm->out.running)) {
0333         struct snd_pcm_runtime *runtime = substream->runtime;
0334
0335         line6pcm->out.pos_done +=
0336             length / bytes_per_frame;
0337
0338         if (line6pcm->out.pos_done >= runtime->buffer_size)
0339             line6pcm->out.pos_done -= runtime->buffer_size;
0340     }
0341
0342     clear_bit(index, &line6pcm->out.active_urbs);
0343
0344     for (i = 0; i < LINE6_ISO_PACKETS; i++)
0345         if (urb->iso_frame_desc[i].status == -EXDEV) {
0346             shutdown = 1;
0347             break;
0348         }
0349
0350     if (test_and_clear_bit(index, &line6pcm->out.unlink_urbs))
0351         shutdown = 1;
0352
0353     if (!shutdown) {
0354         submit_audio_out_urb(line6pcm);
0355
0356         if (test_bit(LINE6_STREAM_PCM, &line6pcm->out.running)) {
0357             line6pcm->out.bytes += length;
0358             if (line6pcm->out.bytes >= line6pcm->out.period) {
0359                 line6pcm->out.bytes %= line6pcm->out.period;
0360                 spin_unlock(&line6pcm->out.lock);
0361                 snd_pcm_period_elapsed(substream);
0362                 spin_lock(&line6pcm->out.lock);
0363             }
0364         }
0365     }
0366     spin_unlock_irqrestore(&line6pcm->out.lock, flags);
0367 }
0368
0369 /* open playback callback */
0370 static int snd_line6_playback_open(struct snd_pcm_substream *substream)
0371 {
0372     int err;
0373     struct snd_pcm_runtime *runtime = substream->runtime;
0374     struct snd_line6_pcm *line6pcm = snd_pcm_substream_chip(substream);
0375
0376     err = snd_pcm_hw_constraint_ratdens(runtime, 0, SNDRV_PCM_HW_PARAM_RATE,
0377                         &line6pcm->properties->rates);
0378     if (err < 0)
0379         return err;
0380
0381     runtime->hw = line6pcm->properties->playback_hw;
0382     return 0;
0383 }
0384
0385 /* close playback callback */
0386 static int snd_line6_playback_close(struct snd_pcm_substream *substream)
0387 {
0388     return 0;
0389 }
0390
0391 /* playback operators */
0392 const struct snd_pcm_ops snd_line6_playback_ops = {
0393     .open = snd_line6_playback_open,
0394     .close = snd_line6_playback_close,
0395     .hw_params = snd_line6_hw_params,
0396     .hw_free = snd_line6_hw_free,
0397     .prepare = snd_line6_prepare,
0398     .trigger = snd_line6_trigger,
0399     .pointer = snd_line6_pointer,
0400 };
0401
0402 int line6_create_audio_out_urbs(struct snd_line6_pcm *line6pcm)
0403 {
0404     struct usb_line6 *line6 = line6pcm->line6;
0405     int i;
0406
0407     line6pcm->out.urbs = kcalloc(line6->iso_buffers, sizeof(struct urb *),
0408                      GFP_KERNEL);
0409     if (line6pcm->out.urbs == NULL)
0410         return -ENOMEM;
0411
0412     /* create audio URBs and fill in constant values: */
0413     for (i = 0; i < line6->iso_buffers; ++i) {
0414         struct urb *urb;
0415
0416         /* URB for audio out: */
0417         urb = line6pcm->out.urbs[i] =
0418             usb_alloc_urb(LINE6_ISO_PACKETS, GFP_KERNEL);
0419
0420         if (urb == NULL)
0421             return -ENOMEM;
0422
0423         urb->dev = line6->usbdev;
0424         urb->pipe =
0425             usb_sndisocpipe(line6->usbdev,
0426                     line6->properties->ep_audio_w &
0427                     USB_ENDPOINT_NUMBER_MASK);
0428         urb->transfer_flags = URB_ISO_ASAP;
0429         urb->start_frame = -1;
0430         urb->number_of_packets = LINE6_ISO_PACKETS;
0431         urb->interval = LINE6_ISO_INTERVAL;
0432         urb->error_count = 0;
0433         urb->complete = audio_out_callback;
0434         if (usb_urb_ep_type_check(urb))
0435             return -EINVAL;
0436     }
0437
0438     return 0;
0439 }