sound/drivers/pcmtest.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Virtual ALSA driver for PCM testing/fuzzing
   4  *
   5  * Copyright 2023 Ivan Orlov <ivan.orlov0322@gmail.com>
   6  *
   7  * This is a simple virtual ALSA driver, which can be used for audio applications/PCM middle layer
   8  * testing or fuzzing.
   9  * It can:
  10  *      - Simulate 'playback' and 'capture' actions
  11  *      - Generate random or pattern-based capture data
  12  *      - Check playback buffer for containing looped template, and notify about the results
  13  *      through the debugfs entry
  14  *      - Inject delays into the playback and capturing processes. See 'inject_delay' parameter.
  15  *      - Inject errors during the PCM callbacks.
  16  *      - Register custom RESET ioctl and notify when it is called through the debugfs entry
  17  *      - Work in interleaved and non-interleaved modes
  18  *      - Support up to 8 substreams
  19  *      - Support up to 4 channels
  20  *      - Support framerates from 8 kHz to 48 kHz
  21  *
  22  * When driver works in the capture mode with multiple channels, it duplicates the looped
  23  * pattern to each separate channel. For example, if we have 2 channels, format = U8, interleaved
  24  * access mode and pattern 'abacaba', the DMA buffer will look like aabbccaabbaaaa..., so buffer for
  25  * each channel will contain abacabaabacaba... Same for the non-interleaved mode.
  26  *
  27  * However, it may break the capturing on the higher framerates with small period size, so it is
  28  * better to choose larger period sizes.
  29  *
  30  * You can find the corresponding selftest in the 'alsa' selftests folder.
  31  */
  32
  33 #include <linux/module.h>
  34 #include <linux/init.h>
  35 #include <sound/pcm.h>
  36 #include <sound/core.h>
  37 #include <linux/dma-mapping.h>
  38 #include <linux/platform_device.h>
  39 #include <linux/timer.h>
  40 #include <linux/random.h>
  41 #include <linux/debugfs.h>
  42 #include <linux/delay.h>
  43
  44 #define TIMER_PER_SEC 5
  45 #define TIMER_INTERVAL (HZ / TIMER_PER_SEC)
  46 #define DELAY_JIFFIES HZ
  47 #define PLAYBACK_SUBSTREAM_CNT  8
  48 #define CAPTURE_SUBSTREAM_CNT   8
  49 #define MAX_CHANNELS_NUM        4
  50
  51 #define DEFAULT_PATTERN         "abacaba"
  52 #define DEFAULT_PATTERN_LEN     7
  53
  54 #define FILL_MODE_RAND  0
  55 #define FILL_MODE_PAT   1
  56
  57 #define MAX_PATTERN_LEN 4096
  58
  59 static int index = -1;
  60 static char *id = "pcmtest";
  61 static bool enable = true;
  62 static int inject_delay;
  63 static bool inject_hwpars_err;
  64 static bool inject_prepare_err;
  65 static bool inject_trigger_err;
  66 static bool inject_open_err;
  67
  68 static short fill_mode = FILL_MODE_PAT;
  69
  70 static u8 playback_capture_test;
  71 static u8 ioctl_reset_test;
  72 static struct dentry *driver_debug_dir;
  73
  74 module_param(index, int, 0444);
  75 MODULE_PARM_DESC(index, "Index value for pcmtest soundcard");
  76 module_param(id, charp, 0444);
  77 MODULE_PARM_DESC(id, "ID string for pcmtest soundcard");
  78 module_param(enable, bool, 0444);
  79 MODULE_PARM_DESC(enable, "Enable pcmtest soundcard.");
  80 module_param(fill_mode, short, 0600);
  81 MODULE_PARM_DESC(fill_mode, "Buffer fill mode: rand(0) or pattern(1)");
  82 module_param(inject_delay, int, 0600);
  83 MODULE_PARM_DESC(inject_delay, "Inject delays during playback/capture (in jiffies)");
  84 module_param(inject_hwpars_err, bool, 0600);
  85 MODULE_PARM_DESC(inject_hwpars_err, "Inject EBUSY error in the 'hw_params' callback");
  86 module_param(inject_prepare_err, bool, 0600);
  87 MODULE_PARM_DESC(inject_prepare_err, "Inject EINVAL error in the 'prepare' callback");
  88 module_param(inject_trigger_err, bool, 0600);
  89 MODULE_PARM_DESC(inject_trigger_err, "Inject EINVAL error in the 'trigger' callback");
  90 module_param(inject_open_err, bool, 0600);
  91 MODULE_PARM_DESC(inject_open_err, "Inject EBUSY error in the 'open' callback");
  92
  93 struct pcmtst {
  94         struct snd_pcm *pcm;
  95         struct snd_card *card;
  96         struct platform_device *pdev;
  97 };
  98
  99 struct pcmtst_buf_iter {
 100         size_t buf_pos;                         // position in the DMA buffer
 101         size_t period_pos;                      // period-relative position
 102         size_t b_rw;                            // Bytes to write on every timer tick
 103         size_t s_rw_ch;                         // Samples to write to one channel on every tick
 104         unsigned int sample_bytes;              // sample_bits / 8
 105         bool is_buf_corrupted;                  // playback test result indicator
 106         size_t period_bytes;                    // bytes in a one period
 107         bool interleaved;                       // Interleaved/Non-interleaved mode
 108         size_t total_bytes;                     // Total bytes read/written
 109         size_t chan_block;                      // Bytes in one channel buffer when non-interleaved
 110         struct snd_pcm_substream *substream;
 111         struct timer_list timer_instance;
 112 };
 113
 114 static struct snd_pcm_hardware snd_pcmtst_hw = {
 115         .info = (SNDRV_PCM_INFO_INTERLEAVED |
 116                  SNDRV_PCM_INFO_BLOCK_TRANSFER |
 117                  SNDRV_PCM_INFO_NONINTERLEAVED |
 118                  SNDRV_PCM_INFO_MMAP_VALID),
 119         .formats =              SNDRV_PCM_FMTBIT_U8 | SNDRV_PCM_FMTBIT_S16_LE,
 120         .rates =                SNDRV_PCM_RATE_8000_48000,
 121         .rate_min =             8000,
 122         .rate_max =             48000,
 123         .channels_min =         1,
 124         .channels_max =         MAX_CHANNELS_NUM,
 125         .buffer_bytes_max =     128 * 1024,
 126         .period_bytes_min =     4096,
 127         .period_bytes_max =     32768,
 128         .periods_min =          1,
 129         .periods_max =          1024,
 130 };
 131
 132 struct pattern_buf {
 133         char *buf;
 134         u32 len;
 135 };
 136
 137 static int buf_allocated;
 138 static struct pattern_buf patt_bufs[MAX_CHANNELS_NUM];
 139
 140 static inline void inc_buf_pos(struct pcmtst_buf_iter *v_iter, size_t by, size_t bytes)
 141 {
 142         v_iter->total_bytes += by;
 143         v_iter->buf_pos += by;
 144         if (v_iter->buf_pos >= bytes)
 145                 v_iter->buf_pos %= bytes;
 146 }
 147
 148 /*
 149  * Position in the DMA buffer when we are in the non-interleaved mode. We increment buf_pos
 150  * every time we write a byte to any channel, so the position in the current channel buffer is
 151  * (position in the DMA buffer) / count_of_channels + size_of_channel_buf * current_channel
 152  */
 153 static inline size_t buf_pos_n(struct pcmtst_buf_iter *v_iter, unsigned int channels,
 154                                unsigned int chan_num)
 155 {
 156         return v_iter->buf_pos / channels + v_iter->chan_block * chan_num;
 157 }
 158
 159 /*
 160  * Get the count of bytes written for the current channel in the interleaved mode.
 161  * This is (count of samples written for the current channel) * bytes_in_sample +
 162  * (relative position in the current sample)
 163  */
 164 static inline size_t ch_pos_i(size_t b_total, unsigned int channels, unsigned int b_sample)
 165 {
 166         return b_total / channels / b_sample * b_sample + (b_total % b_sample);
 167 }
 168
 169 static void check_buf_block_i(struct pcmtst_buf_iter *v_iter, struct snd_pcm_runtime *runtime)
 170 {
 171         size_t i;
 172         short ch_num;
 173         u8 current_byte;
 174
 175         for (i = 0; i < v_iter->b_rw; i++) {
 176                 current_byte = runtime->dma_area[v_iter->buf_pos];
 177                 if (!current_byte)
 178                         break;
 179                 ch_num = (v_iter->total_bytes / v_iter->sample_bytes) % runtime->channels;
 180                 if (current_byte != patt_bufs[ch_num].buf[ch_pos_i(v_iter->total_bytes,
 181                                                                    runtime->channels,
 182                                                                    v_iter->sample_bytes)
 183                                                           % patt_bufs[ch_num].len]) {
 184                         v_iter->is_buf_corrupted = true;
 185                         break;
 186                 }
 187                 inc_buf_pos(v_iter, 1, runtime->dma_bytes);
 188         }
 189         // If we broke during the loop, add remaining bytes to the buffer position.
 190         inc_buf_pos(v_iter, v_iter->b_rw - i, runtime->dma_bytes);
 191 }
 192
 193 static void check_buf_block_ni(struct pcmtst_buf_iter *v_iter, struct snd_pcm_runtime *runtime)
 194 {
 195         unsigned int channels = runtime->channels;
 196         size_t i;
 197         short ch_num;
 198         u8 current_byte;
 199
 200         for (i = 0; i < v_iter->b_rw; i++) {
 201                 ch_num = i % channels;
 202                 current_byte = runtime->dma_area[buf_pos_n(v_iter, channels, ch_num)];
 203                 if (!current_byte)
 204                         break;
 205                 if (current_byte != patt_bufs[ch_num].buf[(v_iter->total_bytes / channels)
 206                                                           % patt_bufs[ch_num].len]) {
 207                         v_iter->is_buf_corrupted = true;
 208                         break;
 209                 }
 210                 inc_buf_pos(v_iter, 1, runtime->dma_bytes);
 211         }
 212         inc_buf_pos(v_iter, v_iter->b_rw - i, runtime->dma_bytes);
 213 }
 214
 215 /*
 216  * Check one block of the buffer. Here we iterate the buffer until we find '0'. This condition is
 217  * necessary because we need to detect when the reading/writing ends, so we assume that the pattern
 218  * doesn't contain zeros.
 219  */
 220 static void check_buf_block(struct pcmtst_buf_iter *v_iter, struct snd_pcm_runtime *runtime)
 221 {
 222         if (v_iter->interleaved)
 223                 check_buf_block_i(v_iter, runtime);
 224         else
 225                 check_buf_block_ni(v_iter, runtime);
 226 }
 227
 228 /*
 229  * Fill buffer in the non-interleaved mode. The order of samples is C0, ..., C0, C1, ..., C1, C2...
 230  * The channel buffers lay in the DMA buffer continuously (see default copy
 231  * handlers in the pcm_lib.c file).
 232  *
 233  * Here we increment the DMA buffer position every time we write a byte to any channel 'buffer'.
 234  * We need this to simulate the correct hardware pointer moving.
 235  */
 236 static void fill_block_pattern_n(struct pcmtst_buf_iter *v_iter, struct snd_pcm_runtime *runtime)
 237 {
 238         size_t i;
 239         unsigned int channels = runtime->channels;
 240         short ch_num;
 241
 242         for (i = 0; i < v_iter->b_rw; i++) {
 243                 ch_num = i % channels;
 244                 runtime->dma_area[buf_pos_n(v_iter, channels, ch_num)] =
 245                         patt_bufs[ch_num].buf[(v_iter->total_bytes / channels)
 246                                               % patt_bufs[ch_num].len];
 247                 inc_buf_pos(v_iter, 1, runtime->dma_bytes);
 248         }
 249 }
 250
 251 // Fill buffer in the interleaved mode. The order of samples is C0, C1, C2, C0, C1, C2, ...
 252 static void fill_block_pattern_i(struct pcmtst_buf_iter *v_iter, struct snd_pcm_runtime *runtime)
 253 {
 254         size_t sample;
 255         size_t pos_in_ch, pos_pattern;
 256         short ch, pos_sample;
 257
 258         pos_in_ch = ch_pos_i(v_iter->total_bytes, runtime->channels, v_iter->sample_bytes);
 259
 260         for (sample = 0; sample < v_iter->s_rw_ch; sample++) {
 261                 for (ch = 0; ch < runtime->channels; ch++) {
 262                         for (pos_sample = 0; pos_sample < v_iter->sample_bytes; pos_sample++) {
 263                                 pos_pattern = (pos_in_ch + sample * v_iter->sample_bytes
 264                                               + pos_sample) % patt_bufs[ch].len;
 265                                 runtime->dma_area[v_iter->buf_pos] = patt_bufs[ch].buf[pos_pattern];
 266                                 inc_buf_pos(v_iter, 1, runtime->dma_bytes);
 267                         }
 268                 }
 269         }
 270 }
 271
 272 static void fill_block_pattern(struct pcmtst_buf_iter *v_iter, struct snd_pcm_runtime *runtime)
 273 {
 274         if (v_iter->interleaved)
 275                 fill_block_pattern_i(v_iter, runtime);
 276         else
 277                 fill_block_pattern_n(v_iter, runtime);
 278 }
 279
 280 static void fill_block_rand_n(struct pcmtst_buf_iter *v_iter, struct snd_pcm_runtime *runtime)
 281 {
 282         unsigned int channels = runtime->channels;
 283         // Remaining space in all channel buffers
 284         size_t bytes_remain = runtime->dma_bytes - v_iter->buf_pos;
 285         unsigned int i;
 286
 287         for (i = 0; i < channels; i++) {
 288                 if (v_iter->b_rw <= bytes_remain) {
 289                         //b_rw - count of bytes must be written for all channels at each timer tick
 290                         get_random_bytes(runtime->dma_area + buf_pos_n(v_iter, channels, i),
 291                                          v_iter->b_rw / channels);
 292                 } else {
 293                         // Write to the end of buffer and start from the beginning of it
 294                         get_random_bytes(runtime->dma_area + buf_pos_n(v_iter, channels, i),
 295                                          bytes_remain / channels);
 296                         get_random_bytes(runtime->dma_area + v_iter->chan_block * i,
 297                                          (v_iter->b_rw - bytes_remain) / channels);
 298                 }
 299         }
 300         inc_buf_pos(v_iter, v_iter->b_rw, runtime->dma_bytes);
 301 }
 302
 303 static void fill_block_rand_i(struct pcmtst_buf_iter *v_iter, struct snd_pcm_runtime *runtime)
 304 {
 305         size_t in_cur_block = runtime->dma_bytes - v_iter->buf_pos;
 306
 307         if (v_iter->b_rw <= in_cur_block) {
 308                 get_random_bytes(&runtime->dma_area[v_iter->buf_pos], v_iter->b_rw);
 309         } else {
 310                 get_random_bytes(&runtime->dma_area[v_iter->buf_pos], in_cur_block);
 311                 get_random_bytes(runtime->dma_area, v_iter->b_rw - in_cur_block);
 312         }
 313         inc_buf_pos(v_iter, v_iter->b_rw, runtime->dma_bytes);
 314 }
 315
 316 static void fill_block_random(struct pcmtst_buf_iter *v_iter, struct snd_pcm_runtime *runtime)
 317 {
 318         if (v_iter->interleaved)
 319                 fill_block_rand_i(v_iter, runtime);
 320         else
 321                 fill_block_rand_n(v_iter, runtime);
 322 }
 323
 324 static void fill_block(struct pcmtst_buf_iter *v_iter, struct snd_pcm_runtime *runtime)
 325 {
 326         switch (fill_mode) {
 327         case FILL_MODE_RAND:
 328                 fill_block_random(v_iter, runtime);
 329                 break;
 330         case FILL_MODE_PAT:
 331                 fill_block_pattern(v_iter, runtime);
 332                 break;
 333         }
 334 }
 335
 336 /*
 337  * Here we iterate through the buffer by (buffer_size / iterates_per_second) bytes.
 338  * The driver uses timer to simulate the hardware pointer moving, and notify the PCM middle layer
 339  * about period elapsed.
 340  */
 341 static void timer_timeout(struct timer_list *data)
 342 {
 343         struct pcmtst_buf_iter *v_iter;
 344         struct snd_pcm_substream *substream;
 345
 346         v_iter = from_timer(v_iter, data, timer_instance);
 347         substream = v_iter->substream;
 348
 349         if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK && !v_iter->is_buf_corrupted)
 350                 check_buf_block(v_iter, substream->runtime);
 351         else if (substream->stream == SNDRV_PCM_STREAM_CAPTURE)
 352                 fill_block(v_iter, substream->runtime);
 353         else
 354                 inc_buf_pos(v_iter, v_iter->b_rw, substream->runtime->dma_bytes);
 355
 356         v_iter->period_pos += v_iter->b_rw;
 357         if (v_iter->period_pos >= v_iter->period_bytes) {
 358                 v_iter->period_pos %= v_iter->period_bytes;
 359                 snd_pcm_period_elapsed(substream);
 360         }
 361         mod_timer(&v_iter->timer_instance, jiffies + TIMER_INTERVAL + inject_delay);
 362 }
 363
 364 static int snd_pcmtst_pcm_open(struct snd_pcm_substream *substream)
 365 {
 366         struct snd_pcm_runtime *runtime = substream->runtime;
 367         struct pcmtst_buf_iter *v_iter;
 368
 369         if (inject_open_err)
 370                 return -EBUSY;
 371
 372         v_iter = kzalloc(sizeof(*v_iter), GFP_KERNEL);
 373         if (!v_iter)
 374                 return -ENOMEM;
 375
 376         runtime->hw = snd_pcmtst_hw;
 377         runtime->private_data = v_iter;
 378         v_iter->substream = substream;
 379         v_iter->buf_pos = 0;
 380         v_iter->is_buf_corrupted = false;
 381         v_iter->period_pos = 0;
 382         v_iter->total_bytes = 0;
 383
 384         playback_capture_test = 0;
 385         ioctl_reset_test = 0;
 386
 387         timer_setup(&v_iter->timer_instance, timer_timeout, 0);
 388         mod_timer(&v_iter->timer_instance, jiffies + TIMER_INTERVAL);
 389         return 0;
 390 }
 391
 392 static int snd_pcmtst_pcm_close(struct snd_pcm_substream *substream)
 393 {
 394         struct pcmtst_buf_iter *v_iter = substream->runtime->private_data;
 395
 396         timer_shutdown_sync(&v_iter->timer_instance);
 397         v_iter->substream = NULL;
 398         playback_capture_test = !v_iter->is_buf_corrupted;
 399         kfree(v_iter);
 400         return 0;
 401 }
 402
 403 static int snd_pcmtst_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
 404 {
 405         if (inject_trigger_err)
 406                 return -EINVAL;
 407
 408         return 0;
 409 }
 410
 411 static snd_pcm_uframes_t snd_pcmtst_pcm_pointer(struct snd_pcm_substream *substream)
 412 {
 413         struct pcmtst_buf_iter *v_iter = substream->runtime->private_data;
 414
 415         return bytes_to_frames(substream->runtime, v_iter->buf_pos);
 416 }
 417
 418 static int snd_pcmtst_free(struct pcmtst *pcmtst)
 419 {
 420         if (!pcmtst)
 421                 return 0;
 422         kfree(pcmtst);
 423         return 0;
 424 }
 425
 426 // These callbacks are required, but empty - all freeing occurs in pdev_remove
 427 static int snd_pcmtst_dev_free(struct snd_device *device)
 428 {
 429         return 0;
 430 }
 431
 432 static void pcmtst_pdev_release(struct device *dev)
 433 {
 434 }
 435
 436 static int snd_pcmtst_pcm_prepare(struct snd_pcm_substream *substream)
 437 {
 438         struct snd_pcm_runtime *runtime = substream->runtime;
 439         struct pcmtst_buf_iter *v_iter = runtime->private_data;
 440
 441         if (inject_prepare_err)
 442                 return -EINVAL;
 443
 444         v_iter->sample_bytes = samples_to_bytes(runtime, 1);
 445         v_iter->period_bytes = snd_pcm_lib_period_bytes(substream);
 446         v_iter->interleaved = true;
 447         if (runtime->access == SNDRV_PCM_ACCESS_RW_NONINTERLEAVED ||
 448             runtime->access == SNDRV_PCM_ACCESS_MMAP_NONINTERLEAVED) {
 449                 v_iter->chan_block = snd_pcm_lib_buffer_bytes(substream) / runtime->channels;
 450                 v_iter->interleaved = false;
 451         }
 452         // We want to record RATE * ch_cnt samples per sec, it is rate * sample_bytes * ch_cnt bytes
 453         v_iter->s_rw_ch = runtime->rate / TIMER_PER_SEC;
 454         v_iter->b_rw = v_iter->s_rw_ch * v_iter->sample_bytes * runtime->channels;
 455
 456         return 0;
 457 }
 458
 459 static int snd_pcmtst_pcm_hw_params(struct snd_pcm_substream *substream,
 460                                     struct snd_pcm_hw_params *params)
 461 {
 462         if (inject_hwpars_err)
 463                 return -EBUSY;
 464         return 0;
 465 }
 466
 467 static int snd_pcmtst_pcm_hw_free(struct snd_pcm_substream *substream)
 468 {
 469         return 0;
 470 }
 471
 472 static int snd_pcmtst_ioctl(struct snd_pcm_substream *substream, unsigned int cmd, void *arg)
 473 {
 474         switch (cmd) {
 475         case SNDRV_PCM_IOCTL1_RESET:
 476                 ioctl_reset_test = 1;
 477                 break;
 478         }
 479         return snd_pcm_lib_ioctl(substream, cmd, arg);
 480 }
 481
 482 static const struct snd_pcm_ops snd_pcmtst_playback_ops = {
 483         .open =         snd_pcmtst_pcm_open,
 484         .close =        snd_pcmtst_pcm_close,
 485         .trigger =      snd_pcmtst_pcm_trigger,
 486         .hw_params =    snd_pcmtst_pcm_hw_params,
 487         .ioctl =        snd_pcmtst_ioctl,
 488         .hw_free =      snd_pcmtst_pcm_hw_free,
 489         .prepare =      snd_pcmtst_pcm_prepare,
 490         .pointer =      snd_pcmtst_pcm_pointer,
 491 };
 492
 493 static const struct snd_pcm_ops snd_pcmtst_capture_ops = {
 494         .open =         snd_pcmtst_pcm_open,
 495         .close =        snd_pcmtst_pcm_close,
 496         .trigger =      snd_pcmtst_pcm_trigger,
 497         .hw_params =    snd_pcmtst_pcm_hw_params,
 498         .hw_free =      snd_pcmtst_pcm_hw_free,
 499         .ioctl =        snd_pcmtst_ioctl,
 500         .prepare =      snd_pcmtst_pcm_prepare,
 501         .pointer =      snd_pcmtst_pcm_pointer,
 502 };
 503
 504 static int snd_pcmtst_new_pcm(struct pcmtst *pcmtst)
 505 {
 506         struct snd_pcm *pcm;
 507         int err;
 508
 509         err = snd_pcm_new(pcmtst->card, "PCMTest", 0, PLAYBACK_SUBSTREAM_CNT,
 510                           CAPTURE_SUBSTREAM_CNT, &pcm);
 511         if (err < 0)
 512                 return err;
 513         pcm->private_data = pcmtst;
 514         strcpy(pcm->name, "PCMTest");
 515         pcmtst->pcm = pcm;
 516         snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, &snd_pcmtst_playback_ops);
 517         snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE, &snd_pcmtst_capture_ops);
 518
 519         err = snd_pcm_set_managed_buffer_all(pcm, SNDRV_DMA_TYPE_DEV, &pcmtst->pdev->dev,
 520                                              0, 128 * 1024);
 521         return err;
 522 }
 523
 524 static int snd_pcmtst_create(struct snd_card *card, struct platform_device *pdev,
 525                              struct pcmtst **r_pcmtst)
 526 {
 527         struct pcmtst *pcmtst;
 528         int err;
 529         static const struct snd_device_ops ops = {
 530                 .dev_free = snd_pcmtst_dev_free,
 531         };
 532
 533         pcmtst = kzalloc(sizeof(*pcmtst), GFP_KERNEL);
 534         if (!pcmtst)
 535                 return -ENOMEM;
 536         pcmtst->card = card;
 537         pcmtst->pdev = pdev;
 538
 539         err = snd_device_new(card, SNDRV_DEV_LOWLEVEL, pcmtst, &ops);
 540         if (err < 0)
 541                 goto _err_free_chip;
 542
 543         err = snd_pcmtst_new_pcm(pcmtst);
 544         if (err < 0)
 545                 goto _err_free_chip;
 546
 547         *r_pcmtst = pcmtst;
 548         return 0;
 549
 550 _err_free_chip:
 551         snd_pcmtst_free(pcmtst);
 552         return err;
 553 }
 554
 555 static int pcmtst_probe(struct platform_device *pdev)
 556 {
 557         struct snd_card *card;
 558         struct pcmtst *pcmtst;
 559         int err;
 560
 561         err = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32));
 562         if (err)
 563                 return err;
 564
 565         err = snd_devm_card_new(&pdev->dev, index, id, THIS_MODULE, 0, &card);
 566         if (err < 0)
 567                 return err;
 568         err = snd_pcmtst_create(card, pdev, &pcmtst);
 569         if (err < 0)
 570                 return err;
 571
 572         strcpy(card->driver, "PCM-TEST Driver");
 573         strcpy(card->shortname, "PCM-Test");
 574         strcpy(card->longname, "PCM-Test virtual driver");
 575
 576         err = snd_card_register(card);
 577         if (err < 0)
 578                 return err;
 579
 580         platform_set_drvdata(pdev, pcmtst);
 581
 582         return 0;
 583 }
 584
 585 static void pdev_remove(struct platform_device *pdev)
 586 {
 587         struct pcmtst *pcmtst = platform_get_drvdata(pdev);
 588
 589         snd_pcmtst_free(pcmtst);
 590 }
 591
 592 static struct platform_device pcmtst_pdev = {
 593         .name =         "pcmtest",
 594         .dev.release =  pcmtst_pdev_release,
 595 };
 596
 597 static struct platform_driver pcmtst_pdrv = {
 598         .probe =        pcmtst_probe,
 599         .remove_new =   pdev_remove,
 600         .driver =       {
 601                 .name = "pcmtest",
 602         },
 603 };
 604
 605 static ssize_t pattern_write(struct file *file, const char __user *u_buff, size_t len, loff_t *off)
 606 {
 607         struct pattern_buf *patt_buf = file->f_inode->i_private;
 608         ssize_t to_write = len;
 609
 610         if (*off + to_write > MAX_PATTERN_LEN)
 611                 to_write = MAX_PATTERN_LEN - *off;
 612
 613         // Crop silently everything over the buffer
 614         if (to_write <= 0)
 615                 return len;
 616
 617         if (copy_from_user(patt_buf->buf + *off, u_buff, to_write))
 618                 return -EFAULT;
 619
 620         patt_buf->len = *off + to_write;
 621         *off += to_write;
 622
 623         return to_write;
 624 }
 625
 626 static ssize_t pattern_read(struct file *file, char __user *u_buff, size_t len, loff_t *off)
 627 {
 628         struct pattern_buf *patt_buf = file->f_inode->i_private;
 629         ssize_t to_read = len;
 630
 631         if (*off + to_read >= MAX_PATTERN_LEN)
 632                 to_read = MAX_PATTERN_LEN - *off;
 633         if (to_read <= 0)
 634                 return 0;
 635
 636         if (copy_to_user(u_buff, patt_buf->buf + *off, to_read))
 637                 to_read = 0;
 638         else
 639                 *off += to_read;
 640
 641         return to_read;
 642 }
 643
 644 static const struct file_operations fill_pattern_fops = {
 645         .read = pattern_read,
 646         .write = pattern_write,
 647 };
 648
 649 static int setup_patt_bufs(void)
 650 {
 651         size_t i;
 652
 653         for (i = 0; i < ARRAY_SIZE(patt_bufs); i++) {
 654                 patt_bufs[i].buf = kzalloc(MAX_PATTERN_LEN, GFP_KERNEL);
 655                 if (!patt_bufs[i].buf)
 656                         break;
 657                 strcpy(patt_bufs[i].buf, DEFAULT_PATTERN);
 658                 patt_bufs[i].len = DEFAULT_PATTERN_LEN;
 659         }
 660
 661         return i;
 662 }
 663
 664 static const char * const pattern_files[] = { "fill_pattern0", "fill_pattern1",
 665                                               "fill_pattern2", "fill_pattern3"};
 666 static int init_debug_files(int buf_count)
 667 {
 668         size_t i;
 669         char len_file_name[32];
 670
 671         driver_debug_dir = debugfs_create_dir("pcmtest", NULL);
 672         if (IS_ERR(driver_debug_dir))
 673                 return PTR_ERR(driver_debug_dir);
 674         debugfs_create_u8("pc_test", 0444, driver_debug_dir, &playback_capture_test);
 675         debugfs_create_u8("ioctl_test", 0444, driver_debug_dir, &ioctl_reset_test);
 676
 677         for (i = 0; i < buf_count; i++) {
 678                 debugfs_create_file(pattern_files[i], 0600, driver_debug_dir,
 679                                     &patt_bufs[i], &fill_pattern_fops);
 680                 snprintf(len_file_name, sizeof(len_file_name), "%s_len", pattern_files[i]);
 681                 debugfs_create_u32(len_file_name, 0444, driver_debug_dir, &patt_bufs[i].len);
 682         }
 683
 684         return 0;
 685 }
 686
 687 static void free_pattern_buffers(void)
 688 {
 689         int i;
 690
 691         for (i = 0; i < buf_allocated; i++)
 692                 kfree(patt_bufs[i].buf);
 693 }
 694
 695 static void clear_debug_files(void)
 696 {
 697         debugfs_remove_recursive(driver_debug_dir);
 698 }
 699
 700 static int __init mod_init(void)
 701 {
 702         int err = 0;
 703
 704         buf_allocated = setup_patt_bufs();
 705         if (!buf_allocated)
 706                 return -ENOMEM;
 707
 708         snd_pcmtst_hw.channels_max = buf_allocated;
 709
 710         err = init_debug_files(buf_allocated);
 711         if (err)
 712                 return err;
 713         err = platform_device_register(&pcmtst_pdev);
 714         if (err)
 715                 return err;
 716         err = platform_driver_register(&pcmtst_pdrv);
 717         if (err)
 718                 platform_device_unregister(&pcmtst_pdev);
 719         return err;
 720 }
 721
 722 static void __exit mod_exit(void)
 723 {
 724         clear_debug_files();
 725         free_pattern_buffers();
 726
 727         platform_driver_unregister(&pcmtst_pdrv);
 728         platform_device_unregister(&pcmtst_pdev);
 729 }
 730
 731 MODULE_LICENSE("GPL");
 732 MODULE_AUTHOR("Ivan Orlov");
 733 module_init(mod_init);
 734 module_exit(mod_exit);