root/sound/soc/fsl/mpc5200_dma.c

DEFINITIONS

1. psc_dma_status_irq
2. psc_dma_bcom_enqueue_next_buffer
3. psc_dma_bcom_irq
4. psc_dma_hw_free
5. psc_dma_trigger
6. psc_dma_open
7. psc_dma_close
8. psc_dma_pointer
9. psc_dma_hw_params
10. psc_dma_new
11. psc_dma_free
12. mpc5200_audio_dma_create
13. mpc5200_audio_dma_destroy

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 //
   3 // Freescale MPC5200 PSC DMA
   4 // ALSA SoC Platform driver
   5 //
   6 // Copyright (C) 2008 Secret Lab Technologies Ltd.
   7 // Copyright (C) 2009 Jon Smirl, Digispeaker
   8 
   9 #include <linux/module.h>
  10 #include <linux/of_device.h>
  11 #include <linux/dma-mapping.h>
  12 #include <linux/slab.h>
  13 #include <linux/of_address.h>
  14 #include <linux/of_irq.h>
  15 #include <linux/of_platform.h>
  16 
  17 #include <sound/soc.h>
  18 
  19 #include <linux/fsl/bestcomm/bestcomm.h>
  20 #include <linux/fsl/bestcomm/gen_bd.h>
  21 #include <asm/mpc52xx_psc.h>
  22 
  23 #include "mpc5200_dma.h"
  24 
  25 #define DRV_NAME "mpc5200_dma"
  26 
  27 /*
  28  * Interrupt handlers
  29  */
  30 static irqreturn_t psc_dma_status_irq(int irq, void *_psc_dma)
  31 {
  32         struct psc_dma *psc_dma = _psc_dma;
  33         struct mpc52xx_psc __iomem *regs = psc_dma->psc_regs;
  34         u16 isr;
  35 
  36         isr = in_be16(&regs->mpc52xx_psc_isr);
  37 
  38         /* Playback underrun error */
  39         if (psc_dma->playback.active && (isr & MPC52xx_PSC_IMR_TXEMP))
  40                 psc_dma->stats.underrun_count++;
  41 
  42         /* Capture overrun error */
  43         if (psc_dma->capture.active && (isr & MPC52xx_PSC_IMR_ORERR))
  44                 psc_dma->stats.overrun_count++;
  45 
  46         out_8(&regs->command, MPC52xx_PSC_RST_ERR_STAT);
  47 
  48         return IRQ_HANDLED;
  49 }
  50 
  51 /**
  52  * psc_dma_bcom_enqueue_next_buffer - Enqueue another audio buffer
  53  * @s: pointer to stream private data structure
  54  *
  55  * Enqueues another audio period buffer into the bestcomm queue.
  56  *
  57  * Note: The routine must only be called when there is space available in
  58  * the queue.  Otherwise the enqueue will fail and the audio ring buffer
  59  * will get out of sync
  60  */
  61 static void psc_dma_bcom_enqueue_next_buffer(struct psc_dma_stream *s)
  62 {
  63         struct bcom_bd *bd;
  64 
  65         /* Prepare and enqueue the next buffer descriptor */
  66         bd = bcom_prepare_next_buffer(s->bcom_task);
  67         bd->status = s->period_bytes;
  68         bd->data[0] = s->runtime->dma_addr + (s->period_next * s->period_bytes);
  69         bcom_submit_next_buffer(s->bcom_task, NULL);
  70 
  71         /* Update for next period */
  72         s->period_next = (s->period_next + 1) % s->runtime->periods;
  73 }
  74 
  75 /* Bestcomm DMA irq handler */
  76 static irqreturn_t psc_dma_bcom_irq(int irq, void *_psc_dma_stream)
  77 {
  78         struct psc_dma_stream *s = _psc_dma_stream;
  79 
  80         spin_lock(&s->psc_dma->lock);
  81         /* For each finished period, dequeue the completed period buffer
  82          * and enqueue a new one in it's place. */
  83         while (bcom_buffer_done(s->bcom_task)) {
  84                 bcom_retrieve_buffer(s->bcom_task, NULL, NULL);
  85 
  86                 s->period_current = (s->period_current+1) % s->runtime->periods;
  87                 s->period_count++;
  88 
  89                 psc_dma_bcom_enqueue_next_buffer(s);
  90         }
  91         spin_unlock(&s->psc_dma->lock);
  92 
  93         /* If the stream is active, then also inform the PCM middle layer
  94          * of the period finished event. */
  95         if (s->active)
  96                 snd_pcm_period_elapsed(s->stream);
  97 
  98         return IRQ_HANDLED;
  99 }
 100 
 101 static int psc_dma_hw_free(struct snd_pcm_substream *substream)
 102 {
 103         snd_pcm_set_runtime_buffer(substream, NULL);
 104         return 0;
 105 }
 106 
 107 /**
 108  * psc_dma_trigger: start and stop the DMA transfer.
 109  *
 110  * This function is called by ALSA to start, stop, pause, and resume the DMA
 111  * transfer of data.
 112  */
 113 static int psc_dma_trigger(struct snd_pcm_substream *substream, int cmd)
 114 {
 115         struct snd_soc_pcm_runtime *rtd = substream->private_data;
 116         struct psc_dma *psc_dma = snd_soc_dai_get_drvdata(rtd->cpu_dai);
 117         struct snd_pcm_runtime *runtime = substream->runtime;
 118         struct psc_dma_stream *s = to_psc_dma_stream(substream, psc_dma);
 119         struct mpc52xx_psc __iomem *regs = psc_dma->psc_regs;
 120         u16 imr;
 121         unsigned long flags;
 122         int i;
 123 
 124         switch (cmd) {
 125         case SNDRV_PCM_TRIGGER_START:
 126                 dev_dbg(psc_dma->dev, "START: stream=%i fbits=%u ps=%u #p=%u\n",
 127                         substream->pstr->stream, runtime->frame_bits,
 128                         (int)runtime->period_size, runtime->periods);
 129                 s->period_bytes = frames_to_bytes(runtime,
 130                                                   runtime->period_size);
 131                 s->period_next = 0;
 132                 s->period_current = 0;
 133                 s->active = 1;
 134                 s->period_count = 0;
 135                 s->runtime = runtime;
 136 
 137                 /* Fill up the bestcomm bd queue and enable DMA.
 138                  * This will begin filling the PSC's fifo.
 139                  */
 140                 spin_lock_irqsave(&psc_dma->lock, flags);
 141 
 142                 if (substream->pstr->stream == SNDRV_PCM_STREAM_CAPTURE)
 143                         bcom_gen_bd_rx_reset(s->bcom_task);
 144                 else
 145                         bcom_gen_bd_tx_reset(s->bcom_task);
 146 
 147                 for (i = 0; i < runtime->periods; i++)
 148                         if (!bcom_queue_full(s->bcom_task))
 149                                 psc_dma_bcom_enqueue_next_buffer(s);
 150 
 151                 bcom_enable(s->bcom_task);
 152                 spin_unlock_irqrestore(&psc_dma->lock, flags);
 153 
 154                 out_8(&regs->command, MPC52xx_PSC_RST_ERR_STAT);
 155 
 156                 break;
 157 
 158         case SNDRV_PCM_TRIGGER_STOP:
 159                 dev_dbg(psc_dma->dev, "STOP: stream=%i periods_count=%i\n",
 160                         substream->pstr->stream, s->period_count);
 161                 s->active = 0;
 162 
 163                 spin_lock_irqsave(&psc_dma->lock, flags);
 164                 bcom_disable(s->bcom_task);
 165                 if (substream->pstr->stream == SNDRV_PCM_STREAM_CAPTURE)
 166                         bcom_gen_bd_rx_reset(s->bcom_task);
 167                 else
 168                         bcom_gen_bd_tx_reset(s->bcom_task);
 169                 spin_unlock_irqrestore(&psc_dma->lock, flags);
 170 
 171                 break;
 172 
 173         default:
 174                 dev_dbg(psc_dma->dev, "unhandled trigger: stream=%i cmd=%i\n",
 175                         substream->pstr->stream, cmd);
 176                 return -EINVAL;
 177         }
 178 
 179         /* Update interrupt enable settings */
 180         imr = 0;
 181         if (psc_dma->playback.active)
 182                 imr |= MPC52xx_PSC_IMR_TXEMP;
 183         if (psc_dma->capture.active)
 184                 imr |= MPC52xx_PSC_IMR_ORERR;
 185         out_be16(&regs->isr_imr.imr, psc_dma->imr | imr);
 186 
 187         return 0;
 188 }
 189 
 190 
 191 /* ---------------------------------------------------------------------
 192  * The PSC DMA 'ASoC platform' driver
 193  *
 194  * Can be referenced by an 'ASoC machine' driver
 195  * This driver only deals with the audio bus; it doesn't have any
 196  * interaction with the attached codec
 197  */
 198 
 199 static const struct snd_pcm_hardware psc_dma_hardware = {
 200         .info = SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_MMAP_VALID |
 201                 SNDRV_PCM_INFO_INTERLEAVED | SNDRV_PCM_INFO_BLOCK_TRANSFER |
 202                 SNDRV_PCM_INFO_BATCH,
 203         .formats = SNDRV_PCM_FMTBIT_S8 | SNDRV_PCM_FMTBIT_S16_BE |
 204                 SNDRV_PCM_FMTBIT_S24_BE | SNDRV_PCM_FMTBIT_S32_BE,
 205         .period_bytes_max       = 1024 * 1024,
 206         .period_bytes_min       = 32,
 207         .periods_min            = 2,
 208         .periods_max            = 256,
 209         .buffer_bytes_max       = 2 * 1024 * 1024,
 210         .fifo_size              = 512,
 211 };
 212 
 213 static int psc_dma_open(struct snd_pcm_substream *substream)
 214 {
 215         struct snd_pcm_runtime *runtime = substream->runtime;
 216         struct snd_soc_pcm_runtime *rtd = substream->private_data;
 217         struct psc_dma *psc_dma = snd_soc_dai_get_drvdata(rtd->cpu_dai);
 218         struct psc_dma_stream *s;
 219         int rc;
 220 
 221         dev_dbg(psc_dma->dev, "psc_dma_open(substream=%p)\n", substream);
 222 
 223         if (substream->pstr->stream == SNDRV_PCM_STREAM_CAPTURE)
 224                 s = &psc_dma->capture;
 225         else
 226                 s = &psc_dma->playback;
 227 
 228         snd_soc_set_runtime_hwparams(substream, &psc_dma_hardware);
 229 
 230         rc = snd_pcm_hw_constraint_integer(runtime,
 231                 SNDRV_PCM_HW_PARAM_PERIODS);
 232         if (rc < 0) {
 233                 dev_err(substream->pcm->card->dev, "invalid buffer size\n");
 234                 return rc;
 235         }
 236 
 237         s->stream = substream;
 238         return 0;
 239 }
 240 
 241 static int psc_dma_close(struct snd_pcm_substream *substream)
 242 {
 243         struct snd_soc_pcm_runtime *rtd = substream->private_data;
 244         struct psc_dma *psc_dma = snd_soc_dai_get_drvdata(rtd->cpu_dai);
 245         struct psc_dma_stream *s;
 246 
 247         dev_dbg(psc_dma->dev, "psc_dma_close(substream=%p)\n", substream);
 248 
 249         if (substream->pstr->stream == SNDRV_PCM_STREAM_CAPTURE)
 250                 s = &psc_dma->capture;
 251         else
 252                 s = &psc_dma->playback;
 253 
 254         if (!psc_dma->playback.active &&
 255             !psc_dma->capture.active) {
 256 
 257                 /* Disable all interrupts and reset the PSC */
 258                 out_be16(&psc_dma->psc_regs->isr_imr.imr, psc_dma->imr);
 259                 out_8(&psc_dma->psc_regs->command, 4 << 4); /* reset error */
 260         }
 261         s->stream = NULL;
 262         return 0;
 263 }
 264 
 265 static snd_pcm_uframes_t
 266 psc_dma_pointer(struct snd_pcm_substream *substream)
 267 {
 268         struct snd_soc_pcm_runtime *rtd = substream->private_data;
 269         struct psc_dma *psc_dma = snd_soc_dai_get_drvdata(rtd->cpu_dai);
 270         struct psc_dma_stream *s;
 271         dma_addr_t count;
 272 
 273         if (substream->pstr->stream == SNDRV_PCM_STREAM_CAPTURE)
 274                 s = &psc_dma->capture;
 275         else
 276                 s = &psc_dma->playback;
 277 
 278         count = s->period_current * s->period_bytes;
 279 
 280         return bytes_to_frames(substream->runtime, count);
 281 }
 282 
 283 static int
 284 psc_dma_hw_params(struct snd_pcm_substream *substream,
 285                          struct snd_pcm_hw_params *params)
 286 {
 287         snd_pcm_set_runtime_buffer(substream, &substream->dma_buffer);
 288 
 289         return 0;
 290 }
 291 
 292 static const struct snd_pcm_ops psc_dma_ops = {
 293         .open           = psc_dma_open,
 294         .close          = psc_dma_close,
 295         .hw_free        = psc_dma_hw_free,
 296         .ioctl          = snd_pcm_lib_ioctl,
 297         .pointer        = psc_dma_pointer,
 298         .trigger        = psc_dma_trigger,
 299         .hw_params      = psc_dma_hw_params,
 300 };
 301 
 302 static int psc_dma_new(struct snd_soc_pcm_runtime *rtd)
 303 {
 304         struct snd_card *card = rtd->card->snd_card;
 305         struct snd_soc_component *component = snd_soc_rtdcom_lookup(rtd, DRV_NAME);
 306         struct snd_soc_dai *dai = rtd->cpu_dai;
 307         struct snd_pcm *pcm = rtd->pcm;
 308         size_t size = psc_dma_hardware.buffer_bytes_max;
 309         int rc;
 310 
 311         dev_dbg(component->dev, "psc_dma_new(card=%p, dai=%p, pcm=%p)\n",
 312                 card, dai, pcm);
 313 
 314         rc = dma_coerce_mask_and_coherent(card->dev, DMA_BIT_MASK(32));
 315         if (rc)
 316                 return rc;
 317 
 318         if (pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream) {
 319                 rc = snd_dma_alloc_pages(SNDRV_DMA_TYPE_DEV, pcm->card->dev,
 320                                 size, &pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream->dma_buffer);
 321                 if (rc)
 322                         goto playback_alloc_err;
 323         }
 324 
 325         if (pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream) {
 326                 rc = snd_dma_alloc_pages(SNDRV_DMA_TYPE_DEV, pcm->card->dev,
 327                                 size, &pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream->dma_buffer);
 328                 if (rc)
 329                         goto capture_alloc_err;
 330         }
 331 
 332         return 0;
 333 
 334  capture_alloc_err:
 335         if (pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream)
 336                 snd_dma_free_pages(&pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream->dma_buffer);
 337 
 338  playback_alloc_err:
 339         dev_err(card->dev, "Cannot allocate buffer(s)\n");
 340 
 341         return -ENOMEM;
 342 }
 343 
 344 static void psc_dma_free(struct snd_pcm *pcm)
 345 {
 346         struct snd_soc_pcm_runtime *rtd = pcm->private_data;
 347         struct snd_soc_component *component = snd_soc_rtdcom_lookup(rtd, DRV_NAME);
 348         struct snd_pcm_substream *substream;
 349         int stream;
 350 
 351         dev_dbg(component->dev, "psc_dma_free(pcm=%p)\n", pcm);
 352 
 353         for (stream = 0; stream < 2; stream++) {
 354                 substream = pcm->streams[stream].substream;
 355                 if (substream) {
 356                         snd_dma_free_pages(&substream->dma_buffer);
 357                         substream->dma_buffer.area = NULL;
 358                         substream->dma_buffer.addr = 0;
 359                 }
 360         }
 361 }
 362 
 363 static const struct snd_soc_component_driver mpc5200_audio_dma_component = {
 364         .name           = DRV_NAME,
 365         .ops            = &psc_dma_ops,
 366         .pcm_new        = &psc_dma_new,
 367         .pcm_free       = &psc_dma_free,
 368 };
 369 
 370 int mpc5200_audio_dma_create(struct platform_device *op)
 371 {
 372         phys_addr_t fifo;
 373         struct psc_dma *psc_dma;
 374         struct resource res;
 375         int size, irq, rc;
 376         const __be32 *prop;
 377         void __iomem *regs;
 378         int ret;
 379 
 380         /* Fetch the registers and IRQ of the PSC */
 381         irq = irq_of_parse_and_map(op->dev.of_node, 0);
 382         if (of_address_to_resource(op->dev.of_node, 0, &res)) {
 383                 dev_err(&op->dev, "Missing reg property\n");
 384                 return -ENODEV;
 385         }
 386         regs = ioremap(res.start, resource_size(&res));
 387         if (!regs) {
 388                 dev_err(&op->dev, "Could not map registers\n");
 389                 return -ENODEV;
 390         }
 391 
 392         /* Allocate and initialize the driver private data */
 393         psc_dma = kzalloc(sizeof *psc_dma, GFP_KERNEL);
 394         if (!psc_dma) {
 395                 ret = -ENOMEM;
 396                 goto out_unmap;
 397         }
 398 
 399         /* Get the PSC ID */
 400         prop = of_get_property(op->dev.of_node, "cell-index", &size);
 401         if (!prop || size < sizeof *prop) {
 402                 ret = -ENODEV;
 403                 goto out_free;
 404         }
 405 
 406         spin_lock_init(&psc_dma->lock);
 407         mutex_init(&psc_dma->mutex);
 408         psc_dma->id = be32_to_cpu(*prop);
 409         psc_dma->irq = irq;
 410         psc_dma->psc_regs = regs;
 411         psc_dma->fifo_regs = regs + sizeof *psc_dma->psc_regs;
 412         psc_dma->dev = &op->dev;
 413         psc_dma->playback.psc_dma = psc_dma;
 414         psc_dma->capture.psc_dma = psc_dma;
 415         snprintf(psc_dma->name, sizeof psc_dma->name, "PSC%u", psc_dma->id);
 416 
 417         /* Find the address of the fifo data registers and setup the
 418          * DMA tasks */
 419         fifo = res.start + offsetof(struct mpc52xx_psc, buffer.buffer_32);
 420         psc_dma->capture.bcom_task =
 421                 bcom_psc_gen_bd_rx_init(psc_dma->id, 10, fifo, 512);
 422         psc_dma->playback.bcom_task =
 423                 bcom_psc_gen_bd_tx_init(psc_dma->id, 10, fifo);
 424         if (!psc_dma->capture.bcom_task ||
 425             !psc_dma->playback.bcom_task) {
 426                 dev_err(&op->dev, "Could not allocate bestcomm tasks\n");
 427                 ret = -ENODEV;
 428                 goto out_free;
 429         }
 430 
 431         /* Disable all interrupts and reset the PSC */
 432         out_be16(&psc_dma->psc_regs->isr_imr.imr, psc_dma->imr);
 433          /* reset receiver */
 434         out_8(&psc_dma->psc_regs->command, MPC52xx_PSC_RST_RX);
 435          /* reset transmitter */
 436         out_8(&psc_dma->psc_regs->command, MPC52xx_PSC_RST_TX);
 437          /* reset error */
 438         out_8(&psc_dma->psc_regs->command, MPC52xx_PSC_RST_ERR_STAT);
 439          /* reset mode */
 440         out_8(&psc_dma->psc_regs->command, MPC52xx_PSC_SEL_MODE_REG_1);
 441 
 442         /* Set up mode register;
 443          * First write: RxRdy (FIFO Alarm) generates rx FIFO irq
 444          * Second write: register Normal mode for non loopback
 445          */
 446         out_8(&psc_dma->psc_regs->mode, 0);
 447         out_8(&psc_dma->psc_regs->mode, 0);
 448 
 449         /* Set the TX and RX fifo alarm thresholds */
 450         out_be16(&psc_dma->fifo_regs->rfalarm, 0x100);
 451         out_8(&psc_dma->fifo_regs->rfcntl, 0x4);
 452         out_be16(&psc_dma->fifo_regs->tfalarm, 0x100);
 453         out_8(&psc_dma->fifo_regs->tfcntl, 0x7);
 454 
 455         /* Lookup the IRQ numbers */
 456         psc_dma->playback.irq =
 457                 bcom_get_task_irq(psc_dma->playback.bcom_task);
 458         psc_dma->capture.irq =
 459                 bcom_get_task_irq(psc_dma->capture.bcom_task);
 460 
 461         rc = request_irq(psc_dma->irq, &psc_dma_status_irq, IRQF_SHARED,
 462                          "psc-dma-status", psc_dma);
 463         rc |= request_irq(psc_dma->capture.irq, &psc_dma_bcom_irq, IRQF_SHARED,
 464                           "psc-dma-capture", &psc_dma->capture);
 465         rc |= request_irq(psc_dma->playback.irq, &psc_dma_bcom_irq, IRQF_SHARED,
 466                           "psc-dma-playback", &psc_dma->playback);
 467         if (rc) {
 468                 ret = -ENODEV;
 469                 goto out_irq;
 470         }
 471 
 472         /* Save what we've done so it can be found again later */
 473         dev_set_drvdata(&op->dev, psc_dma);
 474 
 475         /* Tell the ASoC OF helpers about it */
 476         return devm_snd_soc_register_component(&op->dev,
 477                                         &mpc5200_audio_dma_component, NULL, 0);
 478 out_irq:
 479         free_irq(psc_dma->irq, psc_dma);
 480         free_irq(psc_dma->capture.irq, &psc_dma->capture);
 481         free_irq(psc_dma->playback.irq, &psc_dma->playback);
 482 out_free:
 483         kfree(psc_dma);
 484 out_unmap:
 485         iounmap(regs);
 486         return ret;
 487 }
 488 EXPORT_SYMBOL_GPL(mpc5200_audio_dma_create);
 489 
 490 int mpc5200_audio_dma_destroy(struct platform_device *op)
 491 {
 492         struct psc_dma *psc_dma = dev_get_drvdata(&op->dev);
 493 
 494         dev_dbg(&op->dev, "mpc5200_audio_dma_destroy()\n");
 495 
 496         bcom_gen_bd_rx_release(psc_dma->capture.bcom_task);
 497         bcom_gen_bd_tx_release(psc_dma->playback.bcom_task);
 498 
 499         /* Release irqs */
 500         free_irq(psc_dma->irq, psc_dma);
 501         free_irq(psc_dma->capture.irq, &psc_dma->capture);
 502         free_irq(psc_dma->playback.irq, &psc_dma->playback);
 503 
 504         iounmap(psc_dma->psc_regs);
 505         kfree(psc_dma);
 506         dev_set_drvdata(&op->dev, NULL);
 507 
 508         return 0;
 509 }
 510 EXPORT_SYMBOL_GPL(mpc5200_audio_dma_destroy);
 511 
 512 MODULE_AUTHOR("Grant Likely <grant.likely@secretlab.ca>");
 513 MODULE_DESCRIPTION("Freescale MPC5200 PSC in DMA mode ASoC Driver");
 514 MODULE_LICENSE("GPL");