root/sound/soc/mxs/mxs-saif.c

DEFINITIONS

1. mxs_saif_set_dai_sysclk
2. mxs_saif_get_master
3. mxs_saif_set_clk
4. mxs_saif_put_mclk
5. mxs_saif_get_mclk
6. mxs_saif_set_dai_fmt
7. mxs_saif_startup
8. mxs_saif_shutdown
9. mxs_saif_hw_params
10. mxs_saif_prepare
11. mxs_saif_trigger
12. mxs_saif_dai_probe
13. mxs_saif_irq
14. mxs_saif_mclk_init
15. mxs_saif_probe

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Copyright 2011 Freescale Semiconductor, Inc.
   4  */
   5 
   6 #include <linux/module.h>
   7 #include <linux/init.h>
   8 #include <linux/of.h>
   9 #include <linux/of_device.h>
  10 #include <linux/platform_device.h>
  11 #include <linux/slab.h>
  12 #include <linux/dma-mapping.h>
  13 #include <linux/clk.h>
  14 #include <linux/clk-provider.h>
  15 #include <linux/delay.h>
  16 #include <linux/io.h>
  17 #include <linux/time.h>
  18 #include <sound/core.h>
  19 #include <sound/pcm.h>
  20 #include <sound/pcm_params.h>
  21 #include <sound/soc.h>
  22 
  23 #include "mxs-saif.h"
  24 
  25 #define MXS_SET_ADDR    0x4
  26 #define MXS_CLR_ADDR    0x8
  27 
  28 static struct mxs_saif *mxs_saif[2];
  29 
  30 /*
  31  * SAIF is a little different with other normal SOC DAIs on clock using.
  32  *
  33  * For MXS, two SAIF modules are instantiated on-chip.
  34  * Each SAIF has a set of clock pins and can be operating in master
  35  * mode simultaneously if they are connected to different off-chip codecs.
  36  * Also, one of the two SAIFs can master or drive the clock pins while the
  37  * other SAIF, in slave mode, receives clocking from the master SAIF.
  38  * This also means that both SAIFs must operate at the same sample rate.
  39  *
  40  * We abstract this as each saif has a master, the master could be
  41  * itself or other saifs. In the generic saif driver, saif does not need
  42  * to know the different clkmux. Saif only needs to know who is its master
  43  * and operating its master to generate the proper clock rate for it.
  44  * The master id is provided in mach-specific layer according to different
  45  * clkmux setting.
  46  */
  47 
  48 static int mxs_saif_set_dai_sysclk(struct snd_soc_dai *cpu_dai,
  49                         int clk_id, unsigned int freq, int dir)
  50 {
  51         struct mxs_saif *saif = snd_soc_dai_get_drvdata(cpu_dai);
  52 
  53         switch (clk_id) {
  54         case MXS_SAIF_MCLK:
  55                 saif->mclk = freq;
  56                 break;
  57         default:
  58                 return -EINVAL;
  59         }
  60         return 0;
  61 }
  62 
  63 /*
  64  * Since SAIF may work on EXTMASTER mode, IOW, it's working BITCLK&LRCLK
  65  * is provided by other SAIF, we provide a interface here to get its master
  66  * from its master_id.
  67  * Note that the master could be itself.
  68  */
  69 static inline struct mxs_saif *mxs_saif_get_master(struct mxs_saif * saif)
  70 {
  71         return mxs_saif[saif->master_id];
  72 }
  73 
  74 /*
  75  * Set SAIF clock and MCLK
  76  */
  77 static int mxs_saif_set_clk(struct mxs_saif *saif,
  78                                   unsigned int mclk,
  79                                   unsigned int rate)
  80 {
  81         u32 scr;
  82         int ret;
  83         struct mxs_saif *master_saif;
  84 
  85         dev_dbg(saif->dev, "mclk %d rate %d\n", mclk, rate);
  86 
  87         /* Set master saif to generate proper clock */
  88         master_saif = mxs_saif_get_master(saif);
  89         if (!master_saif)
  90                 return -EINVAL;
  91 
  92         dev_dbg(saif->dev, "master saif%d\n", master_saif->id);
  93 
  94         /* Checking if can playback and capture simutaneously */
  95         if (master_saif->ongoing && rate != master_saif->cur_rate) {
  96                 dev_err(saif->dev,
  97                         "can not change clock, master saif%d(rate %d) is ongoing\n",
  98                         master_saif->id, master_saif->cur_rate);
  99                 return -EINVAL;
 100         }
 101 
 102         scr = __raw_readl(master_saif->base + SAIF_CTRL);
 103         scr &= ~BM_SAIF_CTRL_BITCLK_MULT_RATE;
 104         scr &= ~BM_SAIF_CTRL_BITCLK_BASE_RATE;
 105 
 106         /*
 107          * Set SAIF clock
 108          *
 109          * The SAIF clock should be either 384*fs or 512*fs.
 110          * If MCLK is used, the SAIF clk ratio needs to match mclk ratio.
 111          *  For 256x, 128x, 64x, and 32x sub-rates, set saif clk as 512*fs.
 112          *  For 192x, 96x, and 48x sub-rates, set saif clk as 384*fs.
 113          *
 114          * If MCLK is not used, we just set saif clk to 512*fs.
 115          */
 116         ret = clk_prepare_enable(master_saif->clk);
 117         if (ret)
 118                 return ret;
 119 
 120         if (master_saif->mclk_in_use) {
 121                 switch (mclk / rate) {
 122                 case 32:
 123                 case 64:
 124                 case 128:
 125                 case 256:
 126                 case 512:
 127                         scr &= ~BM_SAIF_CTRL_BITCLK_BASE_RATE;
 128                         ret = clk_set_rate(master_saif->clk, 512 * rate);
 129                         break;
 130                 case 48:
 131                 case 96:
 132                 case 192:
 133                 case 384:
 134                         scr |= BM_SAIF_CTRL_BITCLK_BASE_RATE;
 135                         ret = clk_set_rate(master_saif->clk, 384 * rate);
 136                         break;
 137                 default:
 138                         /* SAIF MCLK should be a sub-rate of 512x or 384x */
 139                         clk_disable_unprepare(master_saif->clk);
 140                         return -EINVAL;
 141                 }
 142         } else {
 143                 ret = clk_set_rate(master_saif->clk, 512 * rate);
 144                 scr &= ~BM_SAIF_CTRL_BITCLK_BASE_RATE;
 145         }
 146 
 147         clk_disable_unprepare(master_saif->clk);
 148 
 149         if (ret)
 150                 return ret;
 151 
 152         master_saif->cur_rate = rate;
 153 
 154         if (!master_saif->mclk_in_use) {
 155                 __raw_writel(scr, master_saif->base + SAIF_CTRL);
 156                 return 0;
 157         }
 158 
 159         /*
 160          * Program the over-sample rate for MCLK output
 161          *
 162          * The available MCLK range is 32x, 48x... 512x. The rate
 163          * could be from 8kHz to 192kH.
 164          */
 165         switch (mclk / rate) {
 166         case 32:
 167                 scr |= BF_SAIF_CTRL_BITCLK_MULT_RATE(4);
 168                 break;
 169         case 64:
 170                 scr |= BF_SAIF_CTRL_BITCLK_MULT_RATE(3);
 171                 break;
 172         case 128:
 173                 scr |= BF_SAIF_CTRL_BITCLK_MULT_RATE(2);
 174                 break;
 175         case 256:
 176                 scr |= BF_SAIF_CTRL_BITCLK_MULT_RATE(1);
 177                 break;
 178         case 512:
 179                 scr |= BF_SAIF_CTRL_BITCLK_MULT_RATE(0);
 180                 break;
 181         case 48:
 182                 scr |= BF_SAIF_CTRL_BITCLK_MULT_RATE(3);
 183                 break;
 184         case 96:
 185                 scr |= BF_SAIF_CTRL_BITCLK_MULT_RATE(2);
 186                 break;
 187         case 192:
 188                 scr |= BF_SAIF_CTRL_BITCLK_MULT_RATE(1);
 189                 break;
 190         case 384:
 191                 scr |= BF_SAIF_CTRL_BITCLK_MULT_RATE(0);
 192                 break;
 193         default:
 194                 return -EINVAL;
 195         }
 196 
 197         __raw_writel(scr, master_saif->base + SAIF_CTRL);
 198 
 199         return 0;
 200 }
 201 
 202 /*
 203  * Put and disable MCLK.
 204  */
 205 int mxs_saif_put_mclk(unsigned int saif_id)
 206 {
 207         struct mxs_saif *saif = mxs_saif[saif_id];
 208         u32 stat;
 209 
 210         if (!saif)
 211                 return -EINVAL;
 212 
 213         stat = __raw_readl(saif->base + SAIF_STAT);
 214         if (stat & BM_SAIF_STAT_BUSY) {
 215                 dev_err(saif->dev, "error: busy\n");
 216                 return -EBUSY;
 217         }
 218 
 219         clk_disable_unprepare(saif->clk);
 220 
 221         /* disable MCLK output */
 222         __raw_writel(BM_SAIF_CTRL_CLKGATE,
 223                 saif->base + SAIF_CTRL + MXS_SET_ADDR);
 224         __raw_writel(BM_SAIF_CTRL_RUN,
 225                 saif->base + SAIF_CTRL + MXS_CLR_ADDR);
 226 
 227         saif->mclk_in_use = 0;
 228         return 0;
 229 }
 230 EXPORT_SYMBOL_GPL(mxs_saif_put_mclk);
 231 
 232 /*
 233  * Get MCLK and set clock rate, then enable it
 234  *
 235  * This interface is used for codecs who are using MCLK provided
 236  * by saif.
 237  */
 238 int mxs_saif_get_mclk(unsigned int saif_id, unsigned int mclk,
 239                                         unsigned int rate)
 240 {
 241         struct mxs_saif *saif = mxs_saif[saif_id];
 242         u32 stat;
 243         int ret;
 244         struct mxs_saif *master_saif;
 245 
 246         if (!saif)
 247                 return -EINVAL;
 248 
 249         /* Clear Reset */
 250         __raw_writel(BM_SAIF_CTRL_SFTRST,
 251                 saif->base + SAIF_CTRL + MXS_CLR_ADDR);
 252 
 253         /* FIXME: need clear clk gate for register r/w */
 254         __raw_writel(BM_SAIF_CTRL_CLKGATE,
 255                 saif->base + SAIF_CTRL + MXS_CLR_ADDR);
 256 
 257         master_saif = mxs_saif_get_master(saif);
 258         if (saif != master_saif) {
 259                 dev_err(saif->dev, "can not get mclk from a non-master saif\n");
 260                 return -EINVAL;
 261         }
 262 
 263         stat = __raw_readl(saif->base + SAIF_STAT);
 264         if (stat & BM_SAIF_STAT_BUSY) {
 265                 dev_err(saif->dev, "error: busy\n");
 266                 return -EBUSY;
 267         }
 268 
 269         saif->mclk_in_use = 1;
 270         ret = mxs_saif_set_clk(saif, mclk, rate);
 271         if (ret)
 272                 return ret;
 273 
 274         ret = clk_prepare_enable(saif->clk);
 275         if (ret)
 276                 return ret;
 277 
 278         /* enable MCLK output */
 279         __raw_writel(BM_SAIF_CTRL_RUN,
 280                 saif->base + SAIF_CTRL + MXS_SET_ADDR);
 281 
 282         return 0;
 283 }
 284 EXPORT_SYMBOL_GPL(mxs_saif_get_mclk);
 285 
 286 /*
 287  * SAIF DAI format configuration.
 288  * Should only be called when port is inactive.
 289  */
 290 static int mxs_saif_set_dai_fmt(struct snd_soc_dai *cpu_dai, unsigned int fmt)
 291 {
 292         u32 scr, stat;
 293         u32 scr0;
 294         struct mxs_saif *saif = snd_soc_dai_get_drvdata(cpu_dai);
 295 
 296         stat = __raw_readl(saif->base + SAIF_STAT);
 297         if (stat & BM_SAIF_STAT_BUSY) {
 298                 dev_err(cpu_dai->dev, "error: busy\n");
 299                 return -EBUSY;
 300         }
 301 
 302         /* If SAIF1 is configured as slave, the clk gate needs to be cleared
 303          * before the register can be written.
 304          */
 305         if (saif->id != saif->master_id) {
 306                 __raw_writel(BM_SAIF_CTRL_SFTRST,
 307                         saif->base + SAIF_CTRL + MXS_CLR_ADDR);
 308                 __raw_writel(BM_SAIF_CTRL_CLKGATE,
 309                         saif->base + SAIF_CTRL + MXS_CLR_ADDR);
 310         }
 311 
 312         scr0 = __raw_readl(saif->base + SAIF_CTRL);
 313         scr0 = scr0 & ~BM_SAIF_CTRL_BITCLK_EDGE & ~BM_SAIF_CTRL_LRCLK_POLARITY \
 314                 & ~BM_SAIF_CTRL_JUSTIFY & ~BM_SAIF_CTRL_DELAY;
 315         scr = 0;
 316 
 317         /* DAI mode */
 318         switch (fmt & SND_SOC_DAIFMT_FORMAT_MASK) {
 319         case SND_SOC_DAIFMT_I2S:
 320                 /* data frame low 1clk before data */
 321                 scr |= BM_SAIF_CTRL_DELAY;
 322                 scr &= ~BM_SAIF_CTRL_LRCLK_POLARITY;
 323                 break;
 324         case SND_SOC_DAIFMT_LEFT_J:
 325                 /* data frame high with data */
 326                 scr &= ~BM_SAIF_CTRL_DELAY;
 327                 scr &= ~BM_SAIF_CTRL_LRCLK_POLARITY;
 328                 scr &= ~BM_SAIF_CTRL_JUSTIFY;
 329                 break;
 330         default:
 331                 return -EINVAL;
 332         }
 333 
 334         /* DAI clock inversion */
 335         switch (fmt & SND_SOC_DAIFMT_INV_MASK) {
 336         case SND_SOC_DAIFMT_IB_IF:
 337                 scr |= BM_SAIF_CTRL_BITCLK_EDGE;
 338                 scr |= BM_SAIF_CTRL_LRCLK_POLARITY;
 339                 break;
 340         case SND_SOC_DAIFMT_IB_NF:
 341                 scr |= BM_SAIF_CTRL_BITCLK_EDGE;
 342                 scr &= ~BM_SAIF_CTRL_LRCLK_POLARITY;
 343                 break;
 344         case SND_SOC_DAIFMT_NB_IF:
 345                 scr &= ~BM_SAIF_CTRL_BITCLK_EDGE;
 346                 scr |= BM_SAIF_CTRL_LRCLK_POLARITY;
 347                 break;
 348         case SND_SOC_DAIFMT_NB_NF:
 349                 scr &= ~BM_SAIF_CTRL_BITCLK_EDGE;
 350                 scr &= ~BM_SAIF_CTRL_LRCLK_POLARITY;
 351                 break;
 352         }
 353 
 354         /*
 355          * Note: We simply just support master mode since SAIF TX can only
 356          * work as master.
 357          * Here the master is relative to codec side.
 358          * Saif internally could be slave when working on EXTMASTER mode.
 359          * We just hide this to machine driver.
 360          */
 361         switch (fmt & SND_SOC_DAIFMT_MASTER_MASK) {
 362         case SND_SOC_DAIFMT_CBS_CFS:
 363                 if (saif->id == saif->master_id)
 364                         scr &= ~BM_SAIF_CTRL_SLAVE_MODE;
 365                 else
 366                         scr |= BM_SAIF_CTRL_SLAVE_MODE;
 367 
 368                 __raw_writel(scr | scr0, saif->base + SAIF_CTRL);
 369                 break;
 370         default:
 371                 return -EINVAL;
 372         }
 373 
 374         return 0;
 375 }
 376 
 377 static int mxs_saif_startup(struct snd_pcm_substream *substream,
 378                            struct snd_soc_dai *cpu_dai)
 379 {
 380         struct mxs_saif *saif = snd_soc_dai_get_drvdata(cpu_dai);
 381         int ret;
 382 
 383         /* clear error status to 0 for each re-open */
 384         saif->fifo_underrun = 0;
 385         saif->fifo_overrun = 0;
 386 
 387         /* Clear Reset for normal operations */
 388         __raw_writel(BM_SAIF_CTRL_SFTRST,
 389                 saif->base + SAIF_CTRL + MXS_CLR_ADDR);
 390 
 391         /* clear clock gate */
 392         __raw_writel(BM_SAIF_CTRL_CLKGATE,
 393                 saif->base + SAIF_CTRL + MXS_CLR_ADDR);
 394 
 395         ret = clk_prepare(saif->clk);
 396         if (ret)
 397                 return ret;
 398 
 399         return 0;
 400 }
 401 
 402 static void mxs_saif_shutdown(struct snd_pcm_substream *substream,
 403                               struct snd_soc_dai *cpu_dai)
 404 {
 405         struct mxs_saif *saif = snd_soc_dai_get_drvdata(cpu_dai);
 406 
 407         clk_unprepare(saif->clk);
 408 }
 409 
 410 /*
 411  * Should only be called when port is inactive.
 412  * although can be called multiple times by upper layers.
 413  */
 414 static int mxs_saif_hw_params(struct snd_pcm_substream *substream,
 415                              struct snd_pcm_hw_params *params,
 416                              struct snd_soc_dai *cpu_dai)
 417 {
 418         struct mxs_saif *saif = snd_soc_dai_get_drvdata(cpu_dai);
 419         struct mxs_saif *master_saif;
 420         u32 scr, stat;
 421         int ret;
 422 
 423         master_saif = mxs_saif_get_master(saif);
 424         if (!master_saif)
 425                 return -EINVAL;
 426 
 427         /* mclk should already be set */
 428         if (!saif->mclk && saif->mclk_in_use) {
 429                 dev_err(cpu_dai->dev, "set mclk first\n");
 430                 return -EINVAL;
 431         }
 432 
 433         stat = __raw_readl(saif->base + SAIF_STAT);
 434         if (!saif->mclk_in_use && (stat & BM_SAIF_STAT_BUSY)) {
 435                 dev_err(cpu_dai->dev, "error: busy\n");
 436                 return -EBUSY;
 437         }
 438 
 439         /*
 440          * Set saif clk based on sample rate.
 441          * If mclk is used, we also set mclk, if not, saif->mclk is
 442          * default 0, means not used.
 443          */
 444         ret = mxs_saif_set_clk(saif, saif->mclk, params_rate(params));
 445         if (ret) {
 446                 dev_err(cpu_dai->dev, "unable to get proper clk\n");
 447                 return ret;
 448         }
 449 
 450         if (saif != master_saif) {
 451                 /*
 452                 * Set an initial clock rate for the saif internal logic to work
 453                 * properly. This is important when working in EXTMASTER mode
 454                 * that uses the other saif's BITCLK&LRCLK but it still needs a
 455                 * basic clock which should be fast enough for the internal
 456                 * logic.
 457                 */
 458                 clk_enable(saif->clk);
 459                 ret = clk_set_rate(saif->clk, 24000000);
 460                 clk_disable(saif->clk);
 461                 if (ret)
 462                         return ret;
 463 
 464                 ret = clk_prepare(master_saif->clk);
 465                 if (ret)
 466                         return ret;
 467         }
 468 
 469         scr = __raw_readl(saif->base + SAIF_CTRL);
 470 
 471         scr &= ~BM_SAIF_CTRL_WORD_LENGTH;
 472         scr &= ~BM_SAIF_CTRL_BITCLK_48XFS_ENABLE;
 473         switch (params_format(params)) {
 474         case SNDRV_PCM_FORMAT_S16_LE:
 475                 scr |= BF_SAIF_CTRL_WORD_LENGTH(0);
 476                 break;
 477         case SNDRV_PCM_FORMAT_S20_3LE:
 478                 scr |= BF_SAIF_CTRL_WORD_LENGTH(4);
 479                 scr |= BM_SAIF_CTRL_BITCLK_48XFS_ENABLE;
 480                 break;
 481         case SNDRV_PCM_FORMAT_S24_LE:
 482                 scr |= BF_SAIF_CTRL_WORD_LENGTH(8);
 483                 scr |= BM_SAIF_CTRL_BITCLK_48XFS_ENABLE;
 484                 break;
 485         default:
 486                 return -EINVAL;
 487         }
 488 
 489         /* Tx/Rx config */
 490         if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
 491                 /* enable TX mode */
 492                 scr &= ~BM_SAIF_CTRL_READ_MODE;
 493         } else {
 494                 /* enable RX mode */
 495                 scr |= BM_SAIF_CTRL_READ_MODE;
 496         }
 497 
 498         __raw_writel(scr, saif->base + SAIF_CTRL);
 499         return 0;
 500 }
 501 
 502 static int mxs_saif_prepare(struct snd_pcm_substream *substream,
 503                            struct snd_soc_dai *cpu_dai)
 504 {
 505         struct mxs_saif *saif = snd_soc_dai_get_drvdata(cpu_dai);
 506 
 507         /* enable FIFO error irqs */
 508         __raw_writel(BM_SAIF_CTRL_FIFO_ERROR_IRQ_EN,
 509                 saif->base + SAIF_CTRL + MXS_SET_ADDR);
 510 
 511         return 0;
 512 }
 513 
 514 static int mxs_saif_trigger(struct snd_pcm_substream *substream, int cmd,
 515                                 struct snd_soc_dai *cpu_dai)
 516 {
 517         struct mxs_saif *saif = snd_soc_dai_get_drvdata(cpu_dai);
 518         struct mxs_saif *master_saif;
 519         u32 delay;
 520         int ret;
 521 
 522         master_saif = mxs_saif_get_master(saif);
 523         if (!master_saif)
 524                 return -EINVAL;
 525 
 526         switch (cmd) {
 527         case SNDRV_PCM_TRIGGER_START:
 528         case SNDRV_PCM_TRIGGER_RESUME:
 529         case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
 530                 if (saif->state == MXS_SAIF_STATE_RUNNING)
 531                         return 0;
 532 
 533                 dev_dbg(cpu_dai->dev, "start\n");
 534 
 535                 ret = clk_enable(master_saif->clk);
 536                 if (ret) {
 537                         dev_err(saif->dev, "Failed to enable master clock\n");
 538                         return ret;
 539                 }
 540 
 541                 /*
 542                  * If the saif's master is not itself, we also need to enable
 543                  * itself clk for its internal basic logic to work.
 544                  */
 545                 if (saif != master_saif) {
 546                         ret = clk_enable(saif->clk);
 547                         if (ret) {
 548                                 dev_err(saif->dev, "Failed to enable master clock\n");
 549                                 clk_disable(master_saif->clk);
 550                                 return ret;
 551                         }
 552 
 553                         __raw_writel(BM_SAIF_CTRL_RUN,
 554                                 saif->base + SAIF_CTRL + MXS_SET_ADDR);
 555                 }
 556 
 557                 if (!master_saif->mclk_in_use)
 558                         __raw_writel(BM_SAIF_CTRL_RUN,
 559                                 master_saif->base + SAIF_CTRL + MXS_SET_ADDR);
 560 
 561                 if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
 562                         /*
 563                          * write data to saif data register to trigger
 564                          * the transfer.
 565                          * For 24-bit format the 32-bit FIFO register stores
 566                          * only one channel, so we need to write twice.
 567                          * This is also safe for the other non 24-bit formats.
 568                          */
 569                         __raw_writel(0, saif->base + SAIF_DATA);
 570                         __raw_writel(0, saif->base + SAIF_DATA);
 571                 } else {
 572                         /*
 573                          * read data from saif data register to trigger
 574                          * the receive.
 575                          * For 24-bit format the 32-bit FIFO register stores
 576                          * only one channel, so we need to read twice.
 577                          * This is also safe for the other non 24-bit formats.
 578                          */
 579                         __raw_readl(saif->base + SAIF_DATA);
 580                         __raw_readl(saif->base + SAIF_DATA);
 581                 }
 582 
 583                 master_saif->ongoing = 1;
 584                 saif->state = MXS_SAIF_STATE_RUNNING;
 585 
 586                 dev_dbg(saif->dev, "CTRL 0x%x STAT 0x%x\n",
 587                         __raw_readl(saif->base + SAIF_CTRL),
 588                         __raw_readl(saif->base + SAIF_STAT));
 589 
 590                 dev_dbg(master_saif->dev, "CTRL 0x%x STAT 0x%x\n",
 591                         __raw_readl(master_saif->base + SAIF_CTRL),
 592                         __raw_readl(master_saif->base + SAIF_STAT));
 593                 break;
 594         case SNDRV_PCM_TRIGGER_SUSPEND:
 595         case SNDRV_PCM_TRIGGER_STOP:
 596         case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
 597                 if (saif->state == MXS_SAIF_STATE_STOPPED)
 598                         return 0;
 599 
 600                 dev_dbg(cpu_dai->dev, "stop\n");
 601 
 602                 /* wait a while for the current sample to complete */
 603                 delay = USEC_PER_SEC / master_saif->cur_rate;
 604 
 605                 if (!master_saif->mclk_in_use) {
 606                         __raw_writel(BM_SAIF_CTRL_RUN,
 607                                 master_saif->base + SAIF_CTRL + MXS_CLR_ADDR);
 608                         udelay(delay);
 609                 }
 610                 clk_disable(master_saif->clk);
 611 
 612                 if (saif != master_saif) {
 613                         __raw_writel(BM_SAIF_CTRL_RUN,
 614                                 saif->base + SAIF_CTRL + MXS_CLR_ADDR);
 615                         udelay(delay);
 616                         clk_disable(saif->clk);
 617                 }
 618 
 619                 master_saif->ongoing = 0;
 620                 saif->state = MXS_SAIF_STATE_STOPPED;
 621 
 622                 break;
 623         default:
 624                 return -EINVAL;
 625         }
 626 
 627         return 0;
 628 }
 629 
 630 #define MXS_SAIF_RATES          SNDRV_PCM_RATE_8000_192000
 631 #define MXS_SAIF_FORMATS \
 632         (SNDRV_PCM_FMTBIT_S16_LE | SNDRV_PCM_FMTBIT_S20_3LE | \
 633         SNDRV_PCM_FMTBIT_S24_LE)
 634 
 635 static const struct snd_soc_dai_ops mxs_saif_dai_ops = {
 636         .startup = mxs_saif_startup,
 637         .shutdown = mxs_saif_shutdown,
 638         .trigger = mxs_saif_trigger,
 639         .prepare = mxs_saif_prepare,
 640         .hw_params = mxs_saif_hw_params,
 641         .set_sysclk = mxs_saif_set_dai_sysclk,
 642         .set_fmt = mxs_saif_set_dai_fmt,
 643 };
 644 
 645 static int mxs_saif_dai_probe(struct snd_soc_dai *dai)
 646 {
 647         struct mxs_saif *saif = dev_get_drvdata(dai->dev);
 648 
 649         snd_soc_dai_set_drvdata(dai, saif);
 650 
 651         return 0;
 652 }
 653 
 654 static struct snd_soc_dai_driver mxs_saif_dai = {
 655         .name = "mxs-saif",
 656         .probe = mxs_saif_dai_probe,
 657         .playback = {
 658                 .channels_min = 2,
 659                 .channels_max = 2,
 660                 .rates = MXS_SAIF_RATES,
 661                 .formats = MXS_SAIF_FORMATS,
 662         },
 663         .capture = {
 664                 .channels_min = 2,
 665                 .channels_max = 2,
 666                 .rates = MXS_SAIF_RATES,
 667                 .formats = MXS_SAIF_FORMATS,
 668         },
 669         .ops = &mxs_saif_dai_ops,
 670 };
 671 
 672 static const struct snd_soc_component_driver mxs_saif_component = {
 673         .name           = "mxs-saif",
 674 };
 675 
 676 static irqreturn_t mxs_saif_irq(int irq, void *dev_id)
 677 {
 678         struct mxs_saif *saif = dev_id;
 679         unsigned int stat;
 680 
 681         stat = __raw_readl(saif->base + SAIF_STAT);
 682         if (!(stat & (BM_SAIF_STAT_FIFO_UNDERFLOW_IRQ |
 683                         BM_SAIF_STAT_FIFO_OVERFLOW_IRQ)))
 684                 return IRQ_NONE;
 685 
 686         if (stat & BM_SAIF_STAT_FIFO_UNDERFLOW_IRQ) {
 687                 dev_dbg(saif->dev, "underrun!!! %d\n", ++saif->fifo_underrun);
 688                 __raw_writel(BM_SAIF_STAT_FIFO_UNDERFLOW_IRQ,
 689                                 saif->base + SAIF_STAT + MXS_CLR_ADDR);
 690         }
 691 
 692         if (stat & BM_SAIF_STAT_FIFO_OVERFLOW_IRQ) {
 693                 dev_dbg(saif->dev, "overrun!!! %d\n", ++saif->fifo_overrun);
 694                 __raw_writel(BM_SAIF_STAT_FIFO_OVERFLOW_IRQ,
 695                                 saif->base + SAIF_STAT + MXS_CLR_ADDR);
 696         }
 697 
 698         dev_dbg(saif->dev, "SAIF_CTRL %x SAIF_STAT %x\n",
 699                __raw_readl(saif->base + SAIF_CTRL),
 700                __raw_readl(saif->base + SAIF_STAT));
 701 
 702         return IRQ_HANDLED;
 703 }
 704 
 705 static int mxs_saif_mclk_init(struct platform_device *pdev)
 706 {
 707         struct mxs_saif *saif = platform_get_drvdata(pdev);
 708         struct device_node *np = pdev->dev.of_node;
 709         struct clk *clk;
 710         int ret;
 711 
 712         clk = clk_register_divider(&pdev->dev, "mxs_saif_mclk",
 713                                    __clk_get_name(saif->clk), 0,
 714                                    saif->base + SAIF_CTRL,
 715                                    BP_SAIF_CTRL_BITCLK_MULT_RATE, 3,
 716                                    0, NULL);
 717         if (IS_ERR(clk)) {
 718                 ret = PTR_ERR(clk);
 719                 if (ret == -EEXIST)
 720                         return 0;
 721                 dev_err(&pdev->dev, "failed to register mclk: %d\n", ret);
 722                 return PTR_ERR(clk);
 723         }
 724 
 725         ret = of_clk_add_provider(np, of_clk_src_simple_get, clk);
 726         if (ret)
 727                 return ret;
 728 
 729         return 0;
 730 }
 731 
 732 static int mxs_saif_probe(struct platform_device *pdev)
 733 {
 734         struct device_node *np = pdev->dev.of_node;
 735         struct mxs_saif *saif;
 736         int irq, ret = 0;
 737         struct device_node *master;
 738 
 739         if (!np)
 740                 return -EINVAL;
 741 
 742         saif = devm_kzalloc(&pdev->dev, sizeof(*saif), GFP_KERNEL);
 743         if (!saif)
 744                 return -ENOMEM;
 745 
 746         ret = of_alias_get_id(np, "saif");
 747         if (ret < 0)
 748                 return ret;
 749         else
 750                 saif->id = ret;
 751 
 752         if (saif->id >= ARRAY_SIZE(mxs_saif)) {
 753                 dev_err(&pdev->dev, "get wrong saif id\n");
 754                 return -EINVAL;
 755         }
 756 
 757         /*
 758          * If there is no "fsl,saif-master" phandle, it's a saif
 759          * master.  Otherwise, it's a slave and its phandle points
 760          * to the master.
 761          */
 762         master = of_parse_phandle(np, "fsl,saif-master", 0);
 763         if (!master) {
 764                 saif->master_id = saif->id;
 765         } else {
 766                 ret = of_alias_get_id(master, "saif");
 767                 if (ret < 0)
 768                         return ret;
 769                 else
 770                         saif->master_id = ret;
 771 
 772                 if (saif->master_id >= ARRAY_SIZE(mxs_saif)) {
 773                         dev_err(&pdev->dev, "get wrong master id\n");
 774                         return -EINVAL;
 775                 }
 776         }
 777 
 778         mxs_saif[saif->id] = saif;
 779 
 780         saif->clk = devm_clk_get(&pdev->dev, NULL);
 781         if (IS_ERR(saif->clk)) {
 782                 ret = PTR_ERR(saif->clk);
 783                 dev_err(&pdev->dev, "Cannot get the clock: %d\n",
 784                         ret);
 785                 return ret;
 786         }
 787 
 788         saif->base = devm_platform_ioremap_resource(pdev, 0);
 789         if (IS_ERR(saif->base))
 790                 return PTR_ERR(saif->base);
 791 
 792         irq = platform_get_irq(pdev, 0);
 793         if (irq < 0)
 794                 return irq;
 795 
 796         saif->dev = &pdev->dev;
 797         ret = devm_request_irq(&pdev->dev, irq, mxs_saif_irq, 0,
 798                                dev_name(&pdev->dev), saif);
 799         if (ret) {
 800                 dev_err(&pdev->dev, "failed to request irq\n");
 801                 return ret;
 802         }
 803 
 804         platform_set_drvdata(pdev, saif);
 805 
 806         /* We only support saif0 being tx and clock master */
 807         if (saif->id == 0) {
 808                 ret = mxs_saif_mclk_init(pdev);
 809                 if (ret)
 810                         dev_warn(&pdev->dev, "failed to init clocks\n");
 811         }
 812 
 813         ret = devm_snd_soc_register_component(&pdev->dev, &mxs_saif_component,
 814                                               &mxs_saif_dai, 1);
 815         if (ret) {
 816                 dev_err(&pdev->dev, "register DAI failed\n");
 817                 return ret;
 818         }
 819 
 820         ret = mxs_pcm_platform_register(&pdev->dev);
 821         if (ret) {
 822                 dev_err(&pdev->dev, "register PCM failed: %d\n", ret);
 823                 return ret;
 824         }
 825 
 826         return 0;
 827 }
 828 
 829 static const struct of_device_id mxs_saif_dt_ids[] = {
 830         { .compatible = "fsl,imx28-saif", },
 831         { /* sentinel */ }
 832 };
 833 MODULE_DEVICE_TABLE(of, mxs_saif_dt_ids);
 834 
 835 static struct platform_driver mxs_saif_driver = {
 836         .probe = mxs_saif_probe,
 837 
 838         .driver = {
 839                 .name = "mxs-saif",
 840                 .of_match_table = mxs_saif_dt_ids,
 841         },
 842 };
 843 
 844 module_platform_driver(mxs_saif_driver);
 845 
 846 MODULE_AUTHOR("Freescale Semiconductor, Inc.");
 847 MODULE_DESCRIPTION("MXS ASoC SAIF driver");
 848 MODULE_LICENSE("GPL");
 849 MODULE_ALIAS("platform:mxs-saif");