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