sound/atmel/abdac.c

   1 /*
   2  * Driver for the Atmel on-chip Audio Bitstream DAC (ABDAC)
   3  *
   4  * Copyright (C) 2006-2009 Atmel Corporation
   5  *
   6  * This program is free software; you can redistribute it and/or modify it
   7  * under the terms of the GNU General Public License version 2 as published by
   8  * the Free Software Foundation.
   9  */
  10 #include <linux/clk.h>
  11 #include <linux/bitmap.h>
  12 #include <linux/dw_dmac.h>
  13 #include <linux/dmaengine.h>
  14 #include <linux/dma-mapping.h>
  15 #include <linux/init.h>
  16 #include <linux/interrupt.h>
  17 #include <linux/module.h>
  18 #include <linux/platform_device.h>
  19 #include <linux/types.h>
  20 #include <linux/io.h>
  21
  22 #include <sound/core.h>
  23 #include <sound/initval.h>
  24 #include <sound/pcm.h>
  25 #include <sound/pcm_params.h>
  26 #include <sound/atmel-abdac.h>
  27
  28 /* DAC register offsets */
  29 #define DAC_DATA                                0x0000
  30 #define DAC_CTRL                                0x0008
  31 #define DAC_INT_MASK                            0x000c
  32 #define DAC_INT_EN                              0x0010
  33 #define DAC_INT_DIS                             0x0014
  34 #define DAC_INT_CLR                             0x0018
  35 #define DAC_INT_STATUS                          0x001c
  36
  37 /* Bitfields in CTRL */
  38 #define DAC_SWAP_OFFSET                         30
  39 #define DAC_SWAP_SIZE                           1
  40 #define DAC_EN_OFFSET                           31
  41 #define DAC_EN_SIZE                             1
  42
  43 /* Bitfields in INT_MASK/INT_EN/INT_DIS/INT_STATUS/INT_CLR */
  44 #define DAC_UNDERRUN_OFFSET                     28
  45 #define DAC_UNDERRUN_SIZE                       1
  46 #define DAC_TX_READY_OFFSET                     29
  47 #define DAC_TX_READY_SIZE                       1
  48
  49 /* Bit manipulation macros */
  50 #define DAC_BIT(name)                                   \
  51         (1 << DAC_##name##_OFFSET)
  52 #define DAC_BF(name, value)                             \
  53         (((value) & ((1 << DAC_##name##_SIZE) - 1))     \
  54          << DAC_##name##_OFFSET)
  55 #define DAC_BFEXT(name, value)                          \
  56         (((value) >> DAC_##name##_OFFSET)               \
  57          & ((1 << DAC_##name##_SIZE) - 1))
  58 #define DAC_BFINS(name, value, old)                     \
  59         (((old) & ~(((1 << DAC_##name##_SIZE) - 1)      \
  60                     << DAC_##name##_OFFSET))            \
  61          | DAC_BF(name, value))
  62
  63 /* Register access macros */
  64 #define dac_readl(port, reg)                            \
  65         __raw_readl((port)->regs + DAC_##reg)
  66 #define dac_writel(port, reg, value)                    \
  67         __raw_writel((value), (port)->regs + DAC_##reg)
  68
  69 /*
  70  * ABDAC supports a maximum of 6 different rates from a generic clock. The
  71  * generic clock has a power of two divider, which gives 6 steps from 192 kHz
  72  * to 5112 Hz.
  73  */
  74 #define MAX_NUM_RATES   6
  75 /* ALSA seems to use rates between 192000 Hz and 5112 Hz. */
  76 #define RATE_MAX        192000
  77 #define RATE_MIN        5112
  78
  79 enum {
  80         DMA_READY = 0,
  81 };
  82
  83 struct atmel_abdac_dma {
  84         struct dma_chan         *chan;
  85         struct dw_cyclic_desc   *cdesc;
  86 };
  87
  88 struct atmel_abdac {
  89         struct clk                              *pclk;
  90         struct clk                              *sample_clk;
  91         struct platform_device                  *pdev;
  92         struct atmel_abdac_dma                  dma;
  93
  94         struct snd_pcm_hw_constraint_list       constraints_rates;
  95         struct snd_pcm_substream                *substream;
  96         struct snd_card                         *card;
  97         struct snd_pcm                          *pcm;
  98
  99         void __iomem                            *regs;
 100         unsigned long                           flags;
 101         unsigned int                            rates[MAX_NUM_RATES];
 102         unsigned int                            rates_num;
 103         int                                     irq;
 104 };
 105
 106 #define get_dac(card) ((struct atmel_abdac *)(card)->private_data)
 107
 108 /* This function is called by the DMA driver. */
 109 static void atmel_abdac_dma_period_done(void *arg)
 110 {
 111         struct atmel_abdac *dac = arg;
 112         snd_pcm_period_elapsed(dac->substream);
 113 }
 114
 115 static int atmel_abdac_prepare_dma(struct atmel_abdac *dac,
 116                 struct snd_pcm_substream *substream,
 117                 enum dma_data_direction direction)
 118 {
 119         struct dma_chan                 *chan = dac->dma.chan;
 120         struct dw_cyclic_desc           *cdesc;
 121         struct snd_pcm_runtime          *runtime = substream->runtime;
 122         unsigned long                   buffer_len, period_len;
 123
 124         /*
 125          * We don't do DMA on "complex" transfers, i.e. with
 126          * non-halfword-aligned buffers or lengths.
 127          */
 128         if (runtime->dma_addr & 1 || runtime->buffer_size & 1) {
 129                 dev_dbg(&dac->pdev->dev, "too complex transfer\n");
 130                 return -EINVAL;
 131         }
 132
 133         buffer_len = frames_to_bytes(runtime, runtime->buffer_size);
 134         period_len = frames_to_bytes(runtime, runtime->period_size);
 135
 136         cdesc = dw_dma_cyclic_prep(chan, runtime->dma_addr, buffer_len,
 137                         period_len, DMA_MEM_TO_DEV);
 138         if (IS_ERR(cdesc)) {
 139                 dev_dbg(&dac->pdev->dev, "could not prepare cyclic DMA\n");
 140                 return PTR_ERR(cdesc);
 141         }
 142
 143         cdesc->period_callback = atmel_abdac_dma_period_done;
 144         cdesc->period_callback_param = dac;
 145
 146         dac->dma.cdesc = cdesc;
 147
 148         set_bit(DMA_READY, &dac->flags);
 149
 150         return 0;
 151 }
 152
 153 static struct snd_pcm_hardware atmel_abdac_hw = {
 154         .info                   = (SNDRV_PCM_INFO_MMAP
 155                                   | SNDRV_PCM_INFO_MMAP_VALID
 156                                   | SNDRV_PCM_INFO_INTERLEAVED
 157                                   | SNDRV_PCM_INFO_BLOCK_TRANSFER
 158                                   | SNDRV_PCM_INFO_RESUME
 159                                   | SNDRV_PCM_INFO_PAUSE),
 160         .formats                = (SNDRV_PCM_FMTBIT_S16_BE),
 161         .rates                  = (SNDRV_PCM_RATE_KNOT),
 162         .rate_min               = RATE_MIN,
 163         .rate_max               = RATE_MAX,
 164         .channels_min           = 2,
 165         .channels_max           = 2,
 166         .buffer_bytes_max       = 64 * 4096,
 167         .period_bytes_min       = 4096,
 168         .period_bytes_max       = 4096,
 169         .periods_min            = 6,
 170         .periods_max            = 64,
 171 };
 172
 173 static int atmel_abdac_open(struct snd_pcm_substream *substream)
 174 {
 175         struct atmel_abdac *dac = snd_pcm_substream_chip(substream);
 176
 177         dac->substream = substream;
 178         atmel_abdac_hw.rate_max = dac->rates[dac->rates_num - 1];
 179         atmel_abdac_hw.rate_min = dac->rates[0];
 180         substream->runtime->hw = atmel_abdac_hw;
 181
 182         return snd_pcm_hw_constraint_list(substream->runtime, 0,
 183                         SNDRV_PCM_HW_PARAM_RATE, &dac->constraints_rates);
 184 }
 185
 186 static int atmel_abdac_close(struct snd_pcm_substream *substream)
 187 {
 188         struct atmel_abdac *dac = snd_pcm_substream_chip(substream);
 189         dac->substream = NULL;
 190         return 0;
 191 }
 192
 193 static int atmel_abdac_hw_params(struct snd_pcm_substream *substream,
 194                 struct snd_pcm_hw_params *hw_params)
 195 {
 196         struct atmel_abdac *dac = snd_pcm_substream_chip(substream);
 197         int retval;
 198
 199         retval = snd_pcm_lib_malloc_pages(substream,
 200                         params_buffer_bytes(hw_params));
 201         if (retval < 0)
 202                 return retval;
 203         /* snd_pcm_lib_malloc_pages returns 1 if buffer is changed. */
 204         if (retval == 1)
 205                 if (test_and_clear_bit(DMA_READY, &dac->flags))
 206                         dw_dma_cyclic_free(dac->dma.chan);
 207
 208         return retval;
 209 }
 210
 211 static int atmel_abdac_hw_free(struct snd_pcm_substream *substream)
 212 {
 213         struct atmel_abdac *dac = snd_pcm_substream_chip(substream);
 214         if (test_and_clear_bit(DMA_READY, &dac->flags))
 215                 dw_dma_cyclic_free(dac->dma.chan);
 216         return snd_pcm_lib_free_pages(substream);
 217 }
 218
 219 static int atmel_abdac_prepare(struct snd_pcm_substream *substream)
 220 {
 221         struct atmel_abdac *dac = snd_pcm_substream_chip(substream);
 222         int retval;
 223
 224         retval = clk_set_rate(dac->sample_clk, 256 * substream->runtime->rate);
 225         if (retval)
 226                 return retval;
 227
 228         if (!test_bit(DMA_READY, &dac->flags))
 229                 retval = atmel_abdac_prepare_dma(dac, substream, DMA_TO_DEVICE);
 230
 231         return retval;
 232 }
 233
 234 static int atmel_abdac_trigger(struct snd_pcm_substream *substream, int cmd)
 235 {
 236         struct atmel_abdac *dac = snd_pcm_substream_chip(substream);
 237         int retval = 0;
 238
 239         switch (cmd) {
 240         case SNDRV_PCM_TRIGGER_PAUSE_RELEASE: /* fall through */
 241         case SNDRV_PCM_TRIGGER_RESUME: /* fall through */
 242         case SNDRV_PCM_TRIGGER_START:
 243                 clk_enable(dac->sample_clk);
 244                 retval = dw_dma_cyclic_start(dac->dma.chan);
 245                 if (retval)
 246                         goto out;
 247                 dac_writel(dac, CTRL, DAC_BIT(EN));
 248                 break;
 249         case SNDRV_PCM_TRIGGER_PAUSE_PUSH: /* fall through */
 250         case SNDRV_PCM_TRIGGER_SUSPEND: /* fall through */
 251         case SNDRV_PCM_TRIGGER_STOP:
 252                 dw_dma_cyclic_stop(dac->dma.chan);
 253                 dac_writel(dac, DATA, 0);
 254                 dac_writel(dac, CTRL, 0);
 255                 clk_disable(dac->sample_clk);
 256                 break;
 257         default:
 258                 retval = -EINVAL;
 259                 break;
 260         }
 261 out:
 262         return retval;
 263 }
 264
 265 static snd_pcm_uframes_t
 266 atmel_abdac_pointer(struct snd_pcm_substream *substream)
 267 {
 268         struct atmel_abdac      *dac = snd_pcm_substream_chip(substream);
 269         struct snd_pcm_runtime  *runtime = substream->runtime;
 270         snd_pcm_uframes_t       frames;
 271         unsigned long           bytes;
 272
 273         bytes = dw_dma_get_src_addr(dac->dma.chan);
 274         bytes -= runtime->dma_addr;
 275
 276         frames = bytes_to_frames(runtime, bytes);
 277         if (frames >= runtime->buffer_size)
 278                 frames -= runtime->buffer_size;
 279
 280         return frames;
 281 }
 282
 283 static irqreturn_t abdac_interrupt(int irq, void *dev_id)
 284 {
 285         struct atmel_abdac *dac = dev_id;
 286         u32 status;
 287
 288         status = dac_readl(dac, INT_STATUS);
 289         if (status & DAC_BIT(UNDERRUN)) {
 290                 dev_err(&dac->pdev->dev, "underrun detected\n");
 291                 dac_writel(dac, INT_CLR, DAC_BIT(UNDERRUN));
 292         } else {
 293                 dev_err(&dac->pdev->dev, "spurious interrupt (status=0x%x)\n",
 294                         status);
 295                 dac_writel(dac, INT_CLR, status);
 296         }
 297
 298         return IRQ_HANDLED;
 299 }
 300
 301 static struct snd_pcm_ops atmel_abdac_ops = {
 302         .open           = atmel_abdac_open,
 303         .close          = atmel_abdac_close,
 304         .ioctl          = snd_pcm_lib_ioctl,
 305         .hw_params      = atmel_abdac_hw_params,
 306         .hw_free        = atmel_abdac_hw_free,
 307         .prepare        = atmel_abdac_prepare,
 308         .trigger        = atmel_abdac_trigger,
 309         .pointer        = atmel_abdac_pointer,
 310 };
 311
 312 static int __devinit atmel_abdac_pcm_new(struct atmel_abdac *dac)
 313 {
 314         struct snd_pcm_hardware hw = atmel_abdac_hw;
 315         struct snd_pcm *pcm;
 316         int retval;
 317
 318         retval = snd_pcm_new(dac->card, dac->card->shortname,
 319                         dac->pdev->id, 1, 0, &pcm);
 320         if (retval)
 321                 return retval;
 322
 323         strcpy(pcm->name, dac->card->shortname);
 324         pcm->private_data = dac;
 325         pcm->info_flags = 0;
 326         dac->pcm = pcm;
 327
 328         snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, &atmel_abdac_ops);
 329
 330         retval = snd_pcm_lib_preallocate_pages_for_all(pcm, SNDRV_DMA_TYPE_DEV,
 331                         &dac->pdev->dev, hw.periods_min * hw.period_bytes_min,
 332                         hw.buffer_bytes_max);
 333
 334         return retval;
 335 }
 336
 337 static bool filter(struct dma_chan *chan, void *slave)
 338 {
 339         struct dw_dma_slave *dws = slave;
 340
 341         if (dws->dma_dev == chan->device->dev) {
 342                 chan->private = dws;
 343                 return true;
 344         } else
 345                 return false;
 346 }
 347
 348 static int set_sample_rates(struct atmel_abdac *dac)
 349 {
 350         long new_rate = RATE_MAX;
 351         int retval = -EINVAL;
 352         int index = 0;
 353
 354         /* we start at 192 kHz and work our way down to 5112 Hz */
 355         while (new_rate >= RATE_MIN && index < (MAX_NUM_RATES + 1)) {
 356                 new_rate = clk_round_rate(dac->sample_clk, 256 * new_rate);
 357                 if (new_rate < 0)
 358                         break;
 359                 /* make sure we are below the ABDAC clock */
 360                 if (new_rate <= clk_get_rate(dac->pclk)) {
 361                         dac->rates[index] = new_rate / 256;
 362                         index++;
 363                 }
 364                 /* divide by 256 and then by two to get next rate */
 365                 new_rate /= 256 * 2;
 366         }
 367
 368         if (index) {
 369                 int i;
 370
 371                 /* reverse array, smallest go first */
 372                 for (i = 0; i < (index / 2); i++) {
 373                         unsigned int tmp = dac->rates[index - 1 - i];
 374                         dac->rates[index - 1 - i] = dac->rates[i];
 375                         dac->rates[i] = tmp;
 376                 }
 377
 378                 dac->constraints_rates.count = index;
 379                 dac->constraints_rates.list = dac->rates;
 380                 dac->constraints_rates.mask = 0;
 381                 dac->rates_num = index;
 382
 383                 retval = 0;
 384         }
 385
 386         return retval;
 387 }
 388
 389 static int __devinit atmel_abdac_probe(struct platform_device *pdev)
 390 {
 391         struct snd_card         *card;
 392         struct atmel_abdac      *dac;
 393         struct resource         *regs;
 394         struct atmel_abdac_pdata        *pdata;
 395         struct clk              *pclk;
 396         struct clk              *sample_clk;
 397         int                     retval;
 398         int                     irq;
 399
 400         regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 401         if (!regs) {
 402                 dev_dbg(&pdev->dev, "no memory resource\n");
 403                 return -ENXIO;
 404         }
 405
 406         irq = platform_get_irq(pdev, 0);
 407         if (irq < 0) {
 408                 dev_dbg(&pdev->dev, "could not get IRQ number\n");
 409                 return irq;
 410         }
 411
 412         pdata = pdev->dev.platform_data;
 413         if (!pdata) {
 414                 dev_dbg(&pdev->dev, "no platform data\n");
 415                 return -ENXIO;
 416         }
 417
 418         pclk = clk_get(&pdev->dev, "pclk");
 419         if (IS_ERR(pclk)) {
 420                 dev_dbg(&pdev->dev, "no peripheral clock\n");
 421                 return PTR_ERR(pclk);
 422         }
 423         sample_clk = clk_get(&pdev->dev, "sample_clk");
 424         if (IS_ERR(sample_clk)) {
 425                 dev_dbg(&pdev->dev, "no sample clock\n");
 426                 retval = PTR_ERR(sample_clk);
 427                 goto out_put_pclk;
 428         }
 429         clk_enable(pclk);
 430
 431         retval = snd_card_create(SNDRV_DEFAULT_IDX1, SNDRV_DEFAULT_STR1,
 432                         THIS_MODULE, sizeof(struct atmel_abdac), &card);
 433         if (retval) {
 434                 dev_dbg(&pdev->dev, "could not create sound card device\n");
 435                 goto out_put_sample_clk;
 436         }
 437
 438         dac = get_dac(card);
 439
 440         dac->irq = irq;
 441         dac->card = card;
 442         dac->pclk = pclk;
 443         dac->sample_clk = sample_clk;
 444         dac->pdev = pdev;
 445
 446         retval = set_sample_rates(dac);
 447         if (retval < 0) {
 448                 dev_dbg(&pdev->dev, "could not set supported rates\n");
 449                 goto out_free_card;
 450         }
 451
 452         dac->regs = ioremap(regs->start, resource_size(regs));
 453         if (!dac->regs) {
 454                 dev_dbg(&pdev->dev, "could not remap register memory\n");
 455                 goto out_free_card;
 456         }
 457
 458         /* make sure the DAC is silent and disabled */
 459         dac_writel(dac, DATA, 0);
 460         dac_writel(dac, CTRL, 0);
 461
 462         retval = request_irq(irq, abdac_interrupt, 0, "abdac", dac);
 463         if (retval) {
 464                 dev_dbg(&pdev->dev, "could not request irq\n");
 465                 goto out_unmap_regs;
 466         }
 467
 468         snd_card_set_dev(card, &pdev->dev);
 469
 470         if (pdata->dws.dma_dev) {
 471                 dma_cap_mask_t mask;
 472
 473                 dma_cap_zero(mask);
 474                 dma_cap_set(DMA_SLAVE, mask);
 475
 476                 dac->dma.chan = dma_request_channel(mask, filter, &pdata->dws);
 477                 if (dac->dma.chan) {
 478                         struct dma_slave_config dma_conf = {
 479                                 .dst_addr = regs->start + DAC_DATA,
 480                                 .dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES,
 481                                 .src_maxburst = 1,
 482                                 .dst_maxburst = 1,
 483                                 .direction = DMA_MEM_TO_DEV,
 484                                 .device_fc = false,
 485                         };
 486
 487                         dmaengine_slave_config(dac->dma.chan, &dma_conf);
 488                 }
 489         }
 490         if (!pdata->dws.dma_dev || !dac->dma.chan) {
 491                 dev_dbg(&pdev->dev, "DMA not available\n");
 492                 retval = -ENODEV;
 493                 goto out_unset_card_dev;
 494         }
 495
 496         strcpy(card->driver, "Atmel ABDAC");
 497         strcpy(card->shortname, "Atmel ABDAC");
 498         sprintf(card->longname, "Atmel Audio Bitstream DAC");
 499
 500         retval = atmel_abdac_pcm_new(dac);
 501         if (retval) {
 502                 dev_dbg(&pdev->dev, "could not register ABDAC pcm device\n");
 503                 goto out_release_dma;
 504         }
 505
 506         retval = snd_card_register(card);
 507         if (retval) {
 508                 dev_dbg(&pdev->dev, "could not register sound card\n");
 509                 goto out_release_dma;
 510         }
 511
 512         platform_set_drvdata(pdev, card);
 513
 514         dev_info(&pdev->dev, "Atmel ABDAC at 0x%p using %s\n",
 515                         dac->regs, dev_name(&dac->dma.chan->dev->device));
 516
 517         return retval;
 518
 519 out_release_dma:
 520         dma_release_channel(dac->dma.chan);
 521         dac->dma.chan = NULL;
 522 out_unset_card_dev:
 523         snd_card_set_dev(card, NULL);
 524         free_irq(irq, dac);
 525 out_unmap_regs:
 526         iounmap(dac->regs);
 527 out_free_card:
 528         snd_card_free(card);
 529 out_put_sample_clk:
 530         clk_put(sample_clk);
 531         clk_disable(pclk);
 532 out_put_pclk:
 533         clk_put(pclk);
 534         return retval;
 535 }
 536
 537 #ifdef CONFIG_PM
 538 static int atmel_abdac_suspend(struct platform_device *pdev, pm_message_t msg)
 539 {
 540         struct snd_card *card = platform_get_drvdata(pdev);
 541         struct atmel_abdac *dac = card->private_data;
 542
 543         dw_dma_cyclic_stop(dac->dma.chan);
 544         clk_disable(dac->sample_clk);
 545         clk_disable(dac->pclk);
 546
 547         return 0;
 548 }
 549
 550 static int atmel_abdac_resume(struct platform_device *pdev)
 551 {
 552         struct snd_card *card = platform_get_drvdata(pdev);
 553         struct atmel_abdac *dac = card->private_data;
 554
 555         clk_enable(dac->pclk);
 556         clk_enable(dac->sample_clk);
 557         if (test_bit(DMA_READY, &dac->flags))
 558                 dw_dma_cyclic_start(dac->dma.chan);
 559
 560         return 0;
 561 }
 562 #else
 563 #define atmel_abdac_suspend NULL
 564 #define atmel_abdac_resume NULL
 565 #endif
 566
 567 static int __devexit atmel_abdac_remove(struct platform_device *pdev)
 568 {
 569         struct snd_card *card = platform_get_drvdata(pdev);
 570         struct atmel_abdac *dac = get_dac(card);
 571
 572         clk_put(dac->sample_clk);
 573         clk_disable(dac->pclk);
 574         clk_put(dac->pclk);
 575
 576         dma_release_channel(dac->dma.chan);
 577         dac->dma.chan = NULL;
 578         snd_card_set_dev(card, NULL);
 579         iounmap(dac->regs);
 580         free_irq(dac->irq, dac);
 581         snd_card_free(card);
 582
 583         platform_set_drvdata(pdev, NULL);
 584
 585         return 0;
 586 }
 587
 588 static struct platform_driver atmel_abdac_driver = {
 589         .remove         = __devexit_p(atmel_abdac_remove),
 590         .driver         = {
 591                 .name   = "atmel_abdac",
 592         },
 593         .suspend        = atmel_abdac_suspend,
 594         .resume         = atmel_abdac_resume,
 595 };
 596
 597 static int __init atmel_abdac_init(void)
 598 {
 599         return platform_driver_probe(&atmel_abdac_driver,
 600                         atmel_abdac_probe);
 601 }
 602 module_init(atmel_abdac_init);
 603
 604 static void __exit atmel_abdac_exit(void)
 605 {
 606         platform_driver_unregister(&atmel_abdac_driver);
 607 }
 608 module_exit(atmel_abdac_exit);
 609
 610 MODULE_LICENSE("GPL");
 611 MODULE_DESCRIPTION("Driver for Atmel Audio Bitstream DAC (ABDAC)");
 612 MODULE_AUTHOR("Hans-Christian Egtvedt <egtvedt@samfundet.no>");