sound/soc/cirrus/ep93xx-i2s.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * linux/sound/soc/ep93xx-i2s.c
   4  * EP93xx I2S driver
   5  *
   6  * Copyright (C) 2010 Ryan Mallon
   7  *
   8  * Based on the original driver by:
   9  *   Copyright (C) 2007 Chase Douglas <chasedouglas@gmail>
  10  *   Copyright (C) 2006 Lennert Buytenhek <buytenh@wantstofly.org>
  11  */
  12
  13 #include <linux/module.h>
  14 #include <linux/init.h>
  15 #include <linux/slab.h>
  16 #include <linux/clk.h>
  17 #include <linux/io.h>
  18
  19 #include <sound/core.h>
  20 #include <sound/dmaengine_pcm.h>
  21 #include <sound/pcm.h>
  22 #include <sound/pcm_params.h>
  23 #include <sound/initval.h>
  24 #include <sound/soc.h>
  25
  26 #include <linux/platform_data/dma-ep93xx.h>
  27 #include <linux/soc/cirrus/ep93xx.h>
  28
  29 #include "ep93xx-pcm.h"
  30
  31 #define EP93XX_I2S_TXCLKCFG             0x00
  32 #define EP93XX_I2S_RXCLKCFG             0x04
  33 #define EP93XX_I2S_GLSTS                0x08
  34 #define EP93XX_I2S_GLCTRL               0x0C
  35
  36 #define EP93XX_I2S_I2STX0LFT            0x10
  37 #define EP93XX_I2S_I2STX0RT             0x14
  38
  39 #define EP93XX_I2S_TXLINCTRLDATA        0x28
  40 #define EP93XX_I2S_TXCTRL               0x2C
  41 #define EP93XX_I2S_TXWRDLEN             0x30
  42 #define EP93XX_I2S_TX0EN                0x34
  43
  44 #define EP93XX_I2S_RXLINCTRLDATA        0x58
  45 #define EP93XX_I2S_RXCTRL               0x5C
  46 #define EP93XX_I2S_RXWRDLEN             0x60
  47 #define EP93XX_I2S_RX0EN                0x64
  48
  49 #define EP93XX_I2S_WRDLEN_16            (0 << 0)
  50 #define EP93XX_I2S_WRDLEN_24            (1 << 0)
  51 #define EP93XX_I2S_WRDLEN_32            (2 << 0)
  52
  53 #define EP93XX_I2S_RXLINCTRLDATA_R_JUST BIT(1) /* Right justify */
  54
  55 #define EP93XX_I2S_TXLINCTRLDATA_R_JUST BIT(2) /* Right justify */
  56
  57 /*
  58  * Transmit empty interrupt level select:
  59  * 0 - Generate interrupt when FIFO is half empty
  60  * 1 - Generate interrupt when FIFO is empty
  61  */
  62 #define EP93XX_I2S_TXCTRL_TXEMPTY_LVL   BIT(0)
  63 #define EP93XX_I2S_TXCTRL_TXUFIE        BIT(1) /* Transmit interrupt enable */
  64
  65 #define EP93XX_I2S_CLKCFG_LRS           (1 << 0) /* lrclk polarity */
  66 #define EP93XX_I2S_CLKCFG_CKP           (1 << 1) /* Bit clock polarity */
  67 #define EP93XX_I2S_CLKCFG_REL           (1 << 2) /* First bit transition */
  68 #define EP93XX_I2S_CLKCFG_MASTER        (1 << 3) /* Master mode */
  69 #define EP93XX_I2S_CLKCFG_NBCG          (1 << 4) /* Not bit clock gating */
  70
  71 #define EP93XX_I2S_GLSTS_TX0_FIFO_FULL  BIT(12)
  72
  73 struct ep93xx_i2s_info {
  74         struct clk                      *mclk;
  75         struct clk                      *sclk;
  76         struct clk                      *lrclk;
  77         void __iomem                    *regs;
  78         struct snd_dmaengine_dai_dma_data dma_params_rx;
  79         struct snd_dmaengine_dai_dma_data dma_params_tx;
  80 };
  81
  82 static struct ep93xx_dma_data ep93xx_i2s_dma_data[] = {
  83         [SNDRV_PCM_STREAM_PLAYBACK] = {
  84                 .name           = "i2s-pcm-out",
  85                 .port           = EP93XX_DMA_I2S1,
  86                 .direction      = DMA_MEM_TO_DEV,
  87         },
  88         [SNDRV_PCM_STREAM_CAPTURE] = {
  89                 .name           = "i2s-pcm-in",
  90                 .port           = EP93XX_DMA_I2S1,
  91                 .direction      = DMA_DEV_TO_MEM,
  92         },
  93 };
  94
  95 static inline void ep93xx_i2s_write_reg(struct ep93xx_i2s_info *info,
  96                                         unsigned reg, unsigned val)
  97 {
  98         __raw_writel(val, info->regs + reg);
  99 }
 100
 101 static inline unsigned ep93xx_i2s_read_reg(struct ep93xx_i2s_info *info,
 102                                            unsigned reg)
 103 {
 104         return __raw_readl(info->regs + reg);
 105 }
 106
 107 static void ep93xx_i2s_enable(struct ep93xx_i2s_info *info, int stream)
 108 {
 109         unsigned base_reg;
 110
 111         if ((ep93xx_i2s_read_reg(info, EP93XX_I2S_TX0EN) & 0x1) == 0 &&
 112             (ep93xx_i2s_read_reg(info, EP93XX_I2S_RX0EN) & 0x1) == 0) {
 113                 /* Enable clocks */
 114                 clk_enable(info->mclk);
 115                 clk_enable(info->sclk);
 116                 clk_enable(info->lrclk);
 117
 118                 /* Enable i2s */
 119                 ep93xx_i2s_write_reg(info, EP93XX_I2S_GLCTRL, 1);
 120         }
 121
 122         /* Enable fifo */
 123         if (stream == SNDRV_PCM_STREAM_PLAYBACK)
 124                 base_reg = EP93XX_I2S_TX0EN;
 125         else
 126                 base_reg = EP93XX_I2S_RX0EN;
 127         ep93xx_i2s_write_reg(info, base_reg, 1);
 128
 129         /* Enable TX IRQs (FIFO empty or underflow) */
 130         if (IS_ENABLED(CONFIG_SND_EP93XX_SOC_I2S_WATCHDOG) &&
 131             stream == SNDRV_PCM_STREAM_PLAYBACK)
 132                 ep93xx_i2s_write_reg(info, EP93XX_I2S_TXCTRL,
 133                                      EP93XX_I2S_TXCTRL_TXEMPTY_LVL |
 134                                      EP93XX_I2S_TXCTRL_TXUFIE);
 135 }
 136
 137 static void ep93xx_i2s_disable(struct ep93xx_i2s_info *info, int stream)
 138 {
 139         unsigned base_reg;
 140
 141         /* Disable IRQs */
 142         if (IS_ENABLED(CONFIG_SND_EP93XX_SOC_I2S_WATCHDOG) &&
 143             stream == SNDRV_PCM_STREAM_PLAYBACK)
 144                 ep93xx_i2s_write_reg(info, EP93XX_I2S_TXCTRL, 0);
 145
 146         /* Disable fifo */
 147         if (stream == SNDRV_PCM_STREAM_PLAYBACK)
 148                 base_reg = EP93XX_I2S_TX0EN;
 149         else
 150                 base_reg = EP93XX_I2S_RX0EN;
 151         ep93xx_i2s_write_reg(info, base_reg, 0);
 152
 153         if ((ep93xx_i2s_read_reg(info, EP93XX_I2S_TX0EN) & 0x1) == 0 &&
 154             (ep93xx_i2s_read_reg(info, EP93XX_I2S_RX0EN) & 0x1) == 0) {
 155                 /* Disable i2s */
 156                 ep93xx_i2s_write_reg(info, EP93XX_I2S_GLCTRL, 0);
 157
 158                 /* Disable clocks */
 159                 clk_disable(info->lrclk);
 160                 clk_disable(info->sclk);
 161                 clk_disable(info->mclk);
 162         }
 163 }
 164
 165 /*
 166  * According to documentation I2S controller can handle underflow conditions
 167  * just fine, but in reality the state machine is sometimes confused so that
 168  * the whole stream is shifted by one byte. The watchdog below disables the TX
 169  * FIFO, fills the buffer with zeroes and re-enables the FIFO. State machine
 170  * is being reset and by filling the buffer we get some time before next
 171  * underflow happens.
 172  */
 173 static irqreturn_t ep93xx_i2s_interrupt(int irq, void *dev_id)
 174 {
 175         struct ep93xx_i2s_info *info = dev_id;
 176
 177         /* Disable FIFO */
 178         ep93xx_i2s_write_reg(info, EP93XX_I2S_TX0EN, 0);
 179         /*
 180          * Fill TX FIFO with zeroes, this way we can defer next IRQs as much as
 181          * possible and get more time for DMA to catch up. Actually there are
 182          * only 8 samples in this FIFO, so even on 8kHz maximum deferral here is
 183          * 1ms.
 184          */
 185         while (!(ep93xx_i2s_read_reg(info, EP93XX_I2S_GLSTS) &
 186                  EP93XX_I2S_GLSTS_TX0_FIFO_FULL)) {
 187                 ep93xx_i2s_write_reg(info, EP93XX_I2S_I2STX0LFT, 0);
 188                 ep93xx_i2s_write_reg(info, EP93XX_I2S_I2STX0RT, 0);
 189         }
 190         /* Re-enable FIFO */
 191         ep93xx_i2s_write_reg(info, EP93XX_I2S_TX0EN, 1);
 192
 193         return IRQ_HANDLED;
 194 }
 195
 196 static int ep93xx_i2s_dai_probe(struct snd_soc_dai *dai)
 197 {
 198         struct ep93xx_i2s_info *info = snd_soc_dai_get_drvdata(dai);
 199
 200         info->dma_params_tx.filter_data =
 201                 &ep93xx_i2s_dma_data[SNDRV_PCM_STREAM_PLAYBACK];
 202         info->dma_params_rx.filter_data =
 203                 &ep93xx_i2s_dma_data[SNDRV_PCM_STREAM_CAPTURE];
 204
 205         dai->playback_dma_data = &info->dma_params_tx;
 206         dai->capture_dma_data = &info->dma_params_rx;
 207
 208         return 0;
 209 }
 210
 211 static void ep93xx_i2s_shutdown(struct snd_pcm_substream *substream,
 212                                 struct snd_soc_dai *dai)
 213 {
 214         struct ep93xx_i2s_info *info = snd_soc_dai_get_drvdata(dai);
 215
 216         ep93xx_i2s_disable(info, substream->stream);
 217 }
 218
 219 static int ep93xx_i2s_set_dai_fmt(struct snd_soc_dai *cpu_dai,
 220                                   unsigned int fmt)
 221 {
 222         struct ep93xx_i2s_info *info = snd_soc_dai_get_drvdata(cpu_dai);
 223         unsigned int clk_cfg;
 224         unsigned int txlin_ctrl = 0;
 225         unsigned int rxlin_ctrl = 0;
 226
 227         clk_cfg  = ep93xx_i2s_read_reg(info, EP93XX_I2S_RXCLKCFG);
 228
 229         switch (fmt & SND_SOC_DAIFMT_FORMAT_MASK) {
 230         case SND_SOC_DAIFMT_I2S:
 231                 clk_cfg |= EP93XX_I2S_CLKCFG_REL;
 232                 break;
 233
 234         case SND_SOC_DAIFMT_LEFT_J:
 235                 clk_cfg &= ~EP93XX_I2S_CLKCFG_REL;
 236                 break;
 237
 238         case SND_SOC_DAIFMT_RIGHT_J:
 239                 clk_cfg &= ~EP93XX_I2S_CLKCFG_REL;
 240                 rxlin_ctrl |= EP93XX_I2S_RXLINCTRLDATA_R_JUST;
 241                 txlin_ctrl |= EP93XX_I2S_TXLINCTRLDATA_R_JUST;
 242                 break;
 243
 244         default:
 245                 return -EINVAL;
 246         }
 247
 248         switch (fmt & SND_SOC_DAIFMT_MASTER_MASK) {
 249         case SND_SOC_DAIFMT_CBS_CFS:
 250                 /* CPU is master */
 251                 clk_cfg |= EP93XX_I2S_CLKCFG_MASTER;
 252                 break;
 253
 254         case SND_SOC_DAIFMT_CBM_CFM:
 255                 /* Codec is master */
 256                 clk_cfg &= ~EP93XX_I2S_CLKCFG_MASTER;
 257                 break;
 258
 259         default:
 260                 return -EINVAL;
 261         }
 262
 263         switch (fmt & SND_SOC_DAIFMT_INV_MASK) {
 264         case SND_SOC_DAIFMT_NB_NF:
 265                 /* Negative bit clock, lrclk low on left word */
 266                 clk_cfg &= ~(EP93XX_I2S_CLKCFG_CKP | EP93XX_I2S_CLKCFG_LRS);
 267                 break;
 268
 269         case SND_SOC_DAIFMT_NB_IF:
 270                 /* Negative bit clock, lrclk low on right word */
 271                 clk_cfg &= ~EP93XX_I2S_CLKCFG_CKP;
 272                 clk_cfg |= EP93XX_I2S_CLKCFG_LRS;
 273                 break;
 274
 275         case SND_SOC_DAIFMT_IB_NF:
 276                 /* Positive bit clock, lrclk low on left word */
 277                 clk_cfg |= EP93XX_I2S_CLKCFG_CKP;
 278                 clk_cfg &= ~EP93XX_I2S_CLKCFG_LRS;
 279                 break;
 280
 281         case SND_SOC_DAIFMT_IB_IF:
 282                 /* Positive bit clock, lrclk low on right word */
 283                 clk_cfg |= EP93XX_I2S_CLKCFG_CKP | EP93XX_I2S_CLKCFG_LRS;
 284                 break;
 285         }
 286
 287         /* Write new register values */
 288         ep93xx_i2s_write_reg(info, EP93XX_I2S_RXCLKCFG, clk_cfg);
 289         ep93xx_i2s_write_reg(info, EP93XX_I2S_TXCLKCFG, clk_cfg);
 290         ep93xx_i2s_write_reg(info, EP93XX_I2S_RXLINCTRLDATA, rxlin_ctrl);
 291         ep93xx_i2s_write_reg(info, EP93XX_I2S_TXLINCTRLDATA, txlin_ctrl);
 292         return 0;
 293 }
 294
 295 static int ep93xx_i2s_hw_params(struct snd_pcm_substream *substream,
 296                                 struct snd_pcm_hw_params *params,
 297                                 struct snd_soc_dai *dai)
 298 {
 299         struct ep93xx_i2s_info *info = snd_soc_dai_get_drvdata(dai);
 300         unsigned word_len, div, sdiv, lrdiv;
 301         int err;
 302
 303         switch (params_format(params)) {
 304         case SNDRV_PCM_FORMAT_S16_LE:
 305                 word_len = EP93XX_I2S_WRDLEN_16;
 306                 break;
 307
 308         case SNDRV_PCM_FORMAT_S24_LE:
 309                 word_len = EP93XX_I2S_WRDLEN_24;
 310                 break;
 311
 312         case SNDRV_PCM_FORMAT_S32_LE:
 313                 word_len = EP93XX_I2S_WRDLEN_32;
 314                 break;
 315
 316         default:
 317                 return -EINVAL;
 318         }
 319
 320         if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
 321                 ep93xx_i2s_write_reg(info, EP93XX_I2S_TXWRDLEN, word_len);
 322         else
 323                 ep93xx_i2s_write_reg(info, EP93XX_I2S_RXWRDLEN, word_len);
 324
 325         /*
 326          * EP93xx I2S module can be setup so SCLK / LRCLK value can be
 327          * 32, 64, 128. MCLK / SCLK value can be 2 and 4.
 328          * We set LRCLK equal to `rate' and minimum SCLK / LRCLK
 329          * value is 64, because our sample size is 32 bit * 2 channels.
 330          * I2S standard permits us to transmit more bits than
 331          * the codec uses.
 332          */
 333         div = clk_get_rate(info->mclk) / params_rate(params);
 334         sdiv = 4;
 335         if (div > (256 + 512) / 2) {
 336                 lrdiv = 128;
 337         } else {
 338                 lrdiv = 64;
 339                 if (div < (128 + 256) / 2)
 340                         sdiv = 2;
 341         }
 342
 343         err = clk_set_rate(info->sclk, clk_get_rate(info->mclk) / sdiv);
 344         if (err)
 345                 return err;
 346
 347         err = clk_set_rate(info->lrclk, clk_get_rate(info->sclk) / lrdiv);
 348         if (err)
 349                 return err;
 350
 351         ep93xx_i2s_enable(info, substream->stream);
 352         return 0;
 353 }
 354
 355 static int ep93xx_i2s_set_sysclk(struct snd_soc_dai *cpu_dai, int clk_id,
 356                                  unsigned int freq, int dir)
 357 {
 358         struct ep93xx_i2s_info *info = snd_soc_dai_get_drvdata(cpu_dai);
 359
 360         if (dir == SND_SOC_CLOCK_IN || clk_id != 0)
 361                 return -EINVAL;
 362
 363         return clk_set_rate(info->mclk, freq);
 364 }
 365
 366 #ifdef CONFIG_PM
 367 static int ep93xx_i2s_suspend(struct snd_soc_component *component)
 368 {
 369         struct ep93xx_i2s_info *info = snd_soc_component_get_drvdata(component);
 370
 371         if (!component->active)
 372                 return 0;
 373
 374         ep93xx_i2s_disable(info, SNDRV_PCM_STREAM_PLAYBACK);
 375         ep93xx_i2s_disable(info, SNDRV_PCM_STREAM_CAPTURE);
 376
 377         return 0;
 378 }
 379
 380 static int ep93xx_i2s_resume(struct snd_soc_component *component)
 381 {
 382         struct ep93xx_i2s_info *info = snd_soc_component_get_drvdata(component);
 383
 384         if (!component->active)
 385                 return 0;
 386
 387         ep93xx_i2s_enable(info, SNDRV_PCM_STREAM_PLAYBACK);
 388         ep93xx_i2s_enable(info, SNDRV_PCM_STREAM_CAPTURE);
 389
 390         return 0;
 391 }
 392 #else
 393 #define ep93xx_i2s_suspend      NULL
 394 #define ep93xx_i2s_resume       NULL
 395 #endif
 396
 397 static const struct snd_soc_dai_ops ep93xx_i2s_dai_ops = {
 398         .shutdown       = ep93xx_i2s_shutdown,
 399         .hw_params      = ep93xx_i2s_hw_params,
 400         .set_sysclk     = ep93xx_i2s_set_sysclk,
 401         .set_fmt        = ep93xx_i2s_set_dai_fmt,
 402 };
 403
 404 #define EP93XX_I2S_FORMATS (SNDRV_PCM_FMTBIT_S32_LE)
 405
 406 static struct snd_soc_dai_driver ep93xx_i2s_dai = {
 407         .symmetric_rates= 1,
 408         .probe          = ep93xx_i2s_dai_probe,
 409         .playback       = {
 410                 .channels_min   = 2,
 411                 .channels_max   = 2,
 412                 .rates          = SNDRV_PCM_RATE_8000_192000,
 413                 .formats        = EP93XX_I2S_FORMATS,
 414         },
 415         .capture        = {
 416                  .channels_min  = 2,
 417                  .channels_max  = 2,
 418                  .rates         = SNDRV_PCM_RATE_8000_192000,
 419                  .formats       = EP93XX_I2S_FORMATS,
 420         },
 421         .ops            = &ep93xx_i2s_dai_ops,
 422 };
 423
 424 static const struct snd_soc_component_driver ep93xx_i2s_component = {
 425         .name           = "ep93xx-i2s",
 426         .suspend        = ep93xx_i2s_suspend,
 427         .resume         = ep93xx_i2s_resume,
 428 };
 429
 430 static int ep93xx_i2s_probe(struct platform_device *pdev)
 431 {
 432         struct ep93xx_i2s_info *info;
 433         int err;
 434
 435         info = devm_kzalloc(&pdev->dev, sizeof(*info), GFP_KERNEL);
 436         if (!info)
 437                 return -ENOMEM;
 438
 439         info->regs = devm_platform_ioremap_resource(pdev, 0);
 440         if (IS_ERR(info->regs))
 441                 return PTR_ERR(info->regs);
 442
 443         if (IS_ENABLED(CONFIG_SND_EP93XX_SOC_I2S_WATCHDOG)) {
 444                 int irq = platform_get_irq(pdev, 0);
 445                 if (irq <= 0)
 446                         return irq < 0 ? irq : -ENODEV;
 447
 448                 err = devm_request_irq(&pdev->dev, irq, ep93xx_i2s_interrupt, 0,
 449                                        pdev->name, info);
 450                 if (err)
 451                         return err;
 452         }
 453
 454         info->mclk = clk_get(&pdev->dev, "mclk");
 455         if (IS_ERR(info->mclk)) {
 456                 err = PTR_ERR(info->mclk);
 457                 goto fail;
 458         }
 459
 460         info->sclk = clk_get(&pdev->dev, "sclk");
 461         if (IS_ERR(info->sclk)) {
 462                 err = PTR_ERR(info->sclk);
 463                 goto fail_put_mclk;
 464         }
 465
 466         info->lrclk = clk_get(&pdev->dev, "lrclk");
 467         if (IS_ERR(info->lrclk)) {
 468                 err = PTR_ERR(info->lrclk);
 469                 goto fail_put_sclk;
 470         }
 471
 472         dev_set_drvdata(&pdev->dev, info);
 473
 474         err = devm_snd_soc_register_component(&pdev->dev, &ep93xx_i2s_component,
 475                                          &ep93xx_i2s_dai, 1);
 476         if (err)
 477                 goto fail_put_lrclk;
 478
 479         err = devm_ep93xx_pcm_platform_register(&pdev->dev);
 480         if (err)
 481                 goto fail_put_lrclk;
 482
 483         return 0;
 484
 485 fail_put_lrclk:
 486         clk_put(info->lrclk);
 487 fail_put_sclk:
 488         clk_put(info->sclk);
 489 fail_put_mclk:
 490         clk_put(info->mclk);
 491 fail:
 492         return err;
 493 }
 494
 495 static int ep93xx_i2s_remove(struct platform_device *pdev)
 496 {
 497         struct ep93xx_i2s_info *info = dev_get_drvdata(&pdev->dev);
 498
 499         clk_put(info->lrclk);
 500         clk_put(info->sclk);
 501         clk_put(info->mclk);
 502         return 0;
 503 }
 504
 505 static struct platform_driver ep93xx_i2s_driver = {
 506         .probe  = ep93xx_i2s_probe,
 507         .remove = ep93xx_i2s_remove,
 508         .driver = {
 509                 .name   = "ep93xx-i2s",
 510         },
 511 };
 512
 513 module_platform_driver(ep93xx_i2s_driver);
 514
 515 MODULE_ALIAS("platform:ep93xx-i2s");
 516 MODULE_AUTHOR("Ryan Mallon");
 517 MODULE_DESCRIPTION("EP93XX I2S driver");
 518 MODULE_LICENSE("GPL");