1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * ALSA SoC I2S Audio Layer for Broadcom BCM2835 SoC 4 * 5 * Author: Florian Meier <florian.meier@koalo.de> 6 * Copyright 2013 7 * 8 * Based on 9 * Raspberry Pi PCM I2S ALSA Driver 10 * Copyright (c) by Phil Poole 2013 11 * 12 * ALSA SoC I2S (McBSP) Audio Layer for TI DAVINCI processor 13 * Vladimir Barinov, <vbarinov@embeddedalley.com> 14 * Copyright (C) 2007 MontaVista Software, Inc., <source@mvista.com> 15 * 16 * OMAP ALSA SoC DAI driver using McBSP port 17 * Copyright (C) 2008 Nokia Corporation 18 * Contact: Jarkko Nikula <jarkko.nikula@bitmer.com> 19 * Peter Ujfalusi <peter.ujfalusi@ti.com> 20 * 21 * Freescale SSI ALSA SoC Digital Audio Interface (DAI) driver 22 * Author: Timur Tabi <timur@freescale.com> 23 * Copyright 2007-2010 Freescale Semiconductor, Inc. 24 */ 25 26 #include <linux/bitops.h> 27 #include <linux/clk.h> 28 #include <linux/delay.h> 29 #include <linux/device.h> 30 #include <linux/init.h> 31 #include <linux/io.h> 32 #include <linux/module.h> 33 #include <linux/of_address.h> 34 #include <linux/slab.h> 35 36 #include <sound/core.h> 37 #include <sound/dmaengine_pcm.h> 38 #include <sound/initval.h> 39 #include <sound/pcm.h> 40 #include <sound/pcm_params.h> 41 #include <sound/soc.h> 42 43 /* I2S registers */ 44 #define BCM2835_I2S_CS_A_REG 0x00 45 #define BCM2835_I2S_FIFO_A_REG 0x04 46 #define BCM2835_I2S_MODE_A_REG 0x08 47 #define BCM2835_I2S_RXC_A_REG 0x0c 48 #define BCM2835_I2S_TXC_A_REG 0x10 49 #define BCM2835_I2S_DREQ_A_REG 0x14 50 #define BCM2835_I2S_INTEN_A_REG 0x18 51 #define BCM2835_I2S_INTSTC_A_REG 0x1c 52 #define BCM2835_I2S_GRAY_REG 0x20 53 54 /* I2S register settings */ 55 #define BCM2835_I2S_STBY BIT(25) 56 #define BCM2835_I2S_SYNC BIT(24) 57 #define BCM2835_I2S_RXSEX BIT(23) 58 #define BCM2835_I2S_RXF BIT(22) 59 #define BCM2835_I2S_TXE BIT(21) 60 #define BCM2835_I2S_RXD BIT(20) 61 #define BCM2835_I2S_TXD BIT(19) 62 #define BCM2835_I2S_RXR BIT(18) 63 #define BCM2835_I2S_TXW BIT(17) 64 #define BCM2835_I2S_CS_RXERR BIT(16) 65 #define BCM2835_I2S_CS_TXERR BIT(15) 66 #define BCM2835_I2S_RXSYNC BIT(14) 67 #define BCM2835_I2S_TXSYNC BIT(13) 68 #define BCM2835_I2S_DMAEN BIT(9) 69 #define BCM2835_I2S_RXTHR(v) ((v) << 7) 70 #define BCM2835_I2S_TXTHR(v) ((v) << 5) 71 #define BCM2835_I2S_RXCLR BIT(4) 72 #define BCM2835_I2S_TXCLR BIT(3) 73 #define BCM2835_I2S_TXON BIT(2) 74 #define BCM2835_I2S_RXON BIT(1) 75 #define BCM2835_I2S_EN (1) 76 77 #define BCM2835_I2S_CLKDIS BIT(28) 78 #define BCM2835_I2S_PDMN BIT(27) 79 #define BCM2835_I2S_PDME BIT(26) 80 #define BCM2835_I2S_FRXP BIT(25) 81 #define BCM2835_I2S_FTXP BIT(24) 82 #define BCM2835_I2S_CLKM BIT(23) 83 #define BCM2835_I2S_CLKI BIT(22) 84 #define BCM2835_I2S_FSM BIT(21) 85 #define BCM2835_I2S_FSI BIT(20) 86 #define BCM2835_I2S_FLEN(v) ((v) << 10) 87 #define BCM2835_I2S_FSLEN(v) (v) 88 89 #define BCM2835_I2S_CHWEX BIT(15) 90 #define BCM2835_I2S_CHEN BIT(14) 91 #define BCM2835_I2S_CHPOS(v) ((v) << 4) 92 #define BCM2835_I2S_CHWID(v) (v) 93 #define BCM2835_I2S_CH1(v) ((v) << 16) 94 #define BCM2835_I2S_CH2(v) (v) 95 #define BCM2835_I2S_CH1_POS(v) BCM2835_I2S_CH1(BCM2835_I2S_CHPOS(v)) 96 #define BCM2835_I2S_CH2_POS(v) BCM2835_I2S_CH2(BCM2835_I2S_CHPOS(v)) 97 98 #define BCM2835_I2S_TX_PANIC(v) ((v) << 24) 99 #define BCM2835_I2S_RX_PANIC(v) ((v) << 16) 100 #define BCM2835_I2S_TX(v) ((v) << 8) 101 #define BCM2835_I2S_RX(v) (v) 102 103 #define BCM2835_I2S_INT_RXERR BIT(3) 104 #define BCM2835_I2S_INT_TXERR BIT(2) 105 #define BCM2835_I2S_INT_RXR BIT(1) 106 #define BCM2835_I2S_INT_TXW BIT(0) 107 108 /* Frame length register is 10 bit, maximum length 1024 */ 109 #define BCM2835_I2S_MAX_FRAME_LENGTH 1024 110 111 /* General device struct */ 112 struct bcm2835_i2s_dev { 113 struct device *dev; 114 struct snd_dmaengine_dai_dma_data dma_data[2]; 115 unsigned int fmt; 116 unsigned int tdm_slots; 117 unsigned int rx_mask; 118 unsigned int tx_mask; 119 unsigned int slot_width; 120 unsigned int frame_length; 121 122 struct regmap *i2s_regmap; 123 struct clk *clk; 124 bool clk_prepared; 125 int clk_rate; 126 }; 127 128 static void bcm2835_i2s_start_clock(struct bcm2835_i2s_dev *dev) 129 { 130 unsigned int master = dev->fmt & SND_SOC_DAIFMT_MASTER_MASK; 131 132 if (dev->clk_prepared) 133 return; 134 135 switch (master) { 136 case SND_SOC_DAIFMT_CBS_CFS: 137 case SND_SOC_DAIFMT_CBS_CFM: 138 clk_prepare_enable(dev->clk); 139 dev->clk_prepared = true; 140 break; 141 default: 142 break; 143 } 144 } 145 146 static void bcm2835_i2s_stop_clock(struct bcm2835_i2s_dev *dev) 147 { 148 if (dev->clk_prepared) 149 clk_disable_unprepare(dev->clk); 150 dev->clk_prepared = false; 151 } 152 153 static void bcm2835_i2s_clear_fifos(struct bcm2835_i2s_dev *dev, 154 bool tx, bool rx) 155 { 156 int timeout = 1000; 157 uint32_t syncval; 158 uint32_t csreg; 159 uint32_t i2s_active_state; 160 bool clk_was_prepared; 161 uint32_t off; 162 uint32_t clr; 163 164 off = tx ? BCM2835_I2S_TXON : 0; 165 off |= rx ? BCM2835_I2S_RXON : 0; 166 167 clr = tx ? BCM2835_I2S_TXCLR : 0; 168 clr |= rx ? BCM2835_I2S_RXCLR : 0; 169 170 /* Backup the current state */ 171 regmap_read(dev->i2s_regmap, BCM2835_I2S_CS_A_REG, &csreg); 172 i2s_active_state = csreg & (BCM2835_I2S_RXON | BCM2835_I2S_TXON); 173 174 /* Start clock if not running */ 175 clk_was_prepared = dev->clk_prepared; 176 if (!clk_was_prepared) 177 bcm2835_i2s_start_clock(dev); 178 179 /* Stop I2S module */ 180 regmap_update_bits(dev->i2s_regmap, BCM2835_I2S_CS_A_REG, off, 0); 181 182 /* 183 * Clear the FIFOs 184 * Requires at least 2 PCM clock cycles to take effect 185 */ 186 regmap_update_bits(dev->i2s_regmap, BCM2835_I2S_CS_A_REG, clr, clr); 187 188 /* Wait for 2 PCM clock cycles */ 189 190 /* 191 * Toggle the SYNC flag. After 2 PCM clock cycles it can be read back 192 * FIXME: This does not seem to work for slave mode! 193 */ 194 regmap_read(dev->i2s_regmap, BCM2835_I2S_CS_A_REG, &syncval); 195 syncval &= BCM2835_I2S_SYNC; 196 197 regmap_update_bits(dev->i2s_regmap, BCM2835_I2S_CS_A_REG, 198 BCM2835_I2S_SYNC, ~syncval); 199 200 /* Wait for the SYNC flag changing it's state */ 201 while (--timeout) { 202 regmap_read(dev->i2s_regmap, BCM2835_I2S_CS_A_REG, &csreg); 203 if ((csreg & BCM2835_I2S_SYNC) != syncval) 204 break; 205 } 206 207 if (!timeout) 208 dev_err(dev->dev, "I2S SYNC error!\n"); 209 210 /* Stop clock if it was not running before */ 211 if (!clk_was_prepared) 212 bcm2835_i2s_stop_clock(dev); 213 214 /* Restore I2S state */ 215 regmap_update_bits(dev->i2s_regmap, BCM2835_I2S_CS_A_REG, 216 BCM2835_I2S_RXON | BCM2835_I2S_TXON, i2s_active_state); 217 } 218 219 static int bcm2835_i2s_set_dai_fmt(struct snd_soc_dai *dai, 220 unsigned int fmt) 221 { 222 struct bcm2835_i2s_dev *dev = snd_soc_dai_get_drvdata(dai); 223 dev->fmt = fmt; 224 return 0; 225 } 226 227 static int bcm2835_i2s_set_dai_bclk_ratio(struct snd_soc_dai *dai, 228 unsigned int ratio) 229 { 230 struct bcm2835_i2s_dev *dev = snd_soc_dai_get_drvdata(dai); 231 232 if (!ratio) { 233 dev->tdm_slots = 0; 234 return 0; 235 } 236 237 if (ratio > BCM2835_I2S_MAX_FRAME_LENGTH) 238 return -EINVAL; 239 240 dev->tdm_slots = 2; 241 dev->rx_mask = 0x03; 242 dev->tx_mask = 0x03; 243 dev->slot_width = ratio / 2; 244 dev->frame_length = ratio; 245 246 return 0; 247 } 248 249 static int bcm2835_i2s_set_dai_tdm_slot(struct snd_soc_dai *dai, 250 unsigned int tx_mask, unsigned int rx_mask, 251 int slots, int width) 252 { 253 struct bcm2835_i2s_dev *dev = snd_soc_dai_get_drvdata(dai); 254 255 if (slots) { 256 if (slots < 0 || width < 0) 257 return -EINVAL; 258 259 /* Limit masks to available slots */ 260 rx_mask &= GENMASK(slots - 1, 0); 261 tx_mask &= GENMASK(slots - 1, 0); 262 263 /* 264 * The driver is limited to 2-channel setups. 265 * Check that exactly 2 bits are set in the masks. 266 */ 267 if (hweight_long((unsigned long) rx_mask) != 2 268 || hweight_long((unsigned long) tx_mask) != 2) 269 return -EINVAL; 270 271 if (slots * width > BCM2835_I2S_MAX_FRAME_LENGTH) 272 return -EINVAL; 273 } 274 275 dev->tdm_slots = slots; 276 277 dev->rx_mask = rx_mask; 278 dev->tx_mask = tx_mask; 279 dev->slot_width = width; 280 dev->frame_length = slots * width; 281 282 return 0; 283 } 284 285 /* 286 * Convert logical slot number into physical slot number. 287 * 288 * If odd_offset is 0 sequential number is identical to logical number. 289 * This is used for DSP modes with slot numbering 0 1 2 3 ... 290 * 291 * Otherwise odd_offset defines the physical offset for odd numbered 292 * slots. This is used for I2S and left/right justified modes to 293 * translate from logical slot numbers 0 1 2 3 ... into physical slot 294 * numbers 0 2 ... 3 4 ... 295 */ 296 static int bcm2835_i2s_convert_slot(unsigned int slot, unsigned int odd_offset) 297 { 298 if (!odd_offset) 299 return slot; 300 301 if (slot & 1) 302 return (slot >> 1) + odd_offset; 303 304 return slot >> 1; 305 } 306 307 /* 308 * Calculate channel position from mask and slot width. 309 * 310 * Mask must contain exactly 2 set bits. 311 * Lowest set bit is channel 1 position, highest set bit channel 2. 312 * The constant offset is added to both channel positions. 313 * 314 * If odd_offset is > 0 slot positions are translated to 315 * I2S-style TDM slot numbering ( 0 2 ... 3 4 ...) with odd 316 * logical slot numbers starting at physical slot odd_offset. 317 */ 318 static void bcm2835_i2s_calc_channel_pos( 319 unsigned int *ch1_pos, unsigned int *ch2_pos, 320 unsigned int mask, unsigned int width, 321 unsigned int bit_offset, unsigned int odd_offset) 322 { 323 *ch1_pos = bcm2835_i2s_convert_slot((ffs(mask) - 1), odd_offset) 324 * width + bit_offset; 325 *ch2_pos = bcm2835_i2s_convert_slot((fls(mask) - 1), odd_offset) 326 * width + bit_offset; 327 } 328 329 static int bcm2835_i2s_hw_params(struct snd_pcm_substream *substream, 330 struct snd_pcm_hw_params *params, 331 struct snd_soc_dai *dai) 332 { 333 struct bcm2835_i2s_dev *dev = snd_soc_dai_get_drvdata(dai); 334 unsigned int data_length, data_delay, framesync_length; 335 unsigned int slots, slot_width, odd_slot_offset; 336 int frame_length, bclk_rate; 337 unsigned int rx_mask, tx_mask; 338 unsigned int rx_ch1_pos, rx_ch2_pos, tx_ch1_pos, tx_ch2_pos; 339 unsigned int mode, format; 340 bool bit_clock_master = false; 341 bool frame_sync_master = false; 342 bool frame_start_falling_edge = false; 343 uint32_t csreg; 344 int ret = 0; 345 346 /* 347 * If a stream is already enabled, 348 * the registers are already set properly. 349 */ 350 regmap_read(dev->i2s_regmap, BCM2835_I2S_CS_A_REG, &csreg); 351 352 if (csreg & (BCM2835_I2S_TXON | BCM2835_I2S_RXON)) 353 return 0; 354 355 data_length = params_width(params); 356 data_delay = 0; 357 odd_slot_offset = 0; 358 mode = 0; 359 360 if (dev->tdm_slots) { 361 slots = dev->tdm_slots; 362 slot_width = dev->slot_width; 363 frame_length = dev->frame_length; 364 rx_mask = dev->rx_mask; 365 tx_mask = dev->tx_mask; 366 bclk_rate = dev->frame_length * params_rate(params); 367 } else { 368 slots = 2; 369 slot_width = params_width(params); 370 rx_mask = 0x03; 371 tx_mask = 0x03; 372 373 frame_length = snd_soc_params_to_frame_size(params); 374 if (frame_length < 0) 375 return frame_length; 376 377 bclk_rate = snd_soc_params_to_bclk(params); 378 if (bclk_rate < 0) 379 return bclk_rate; 380 } 381 382 /* Check if data fits into slots */ 383 if (data_length > slot_width) 384 return -EINVAL; 385 386 /* Check if CPU is bit clock master */ 387 switch (dev->fmt & SND_SOC_DAIFMT_MASTER_MASK) { 388 case SND_SOC_DAIFMT_CBS_CFS: 389 case SND_SOC_DAIFMT_CBS_CFM: 390 bit_clock_master = true; 391 break; 392 case SND_SOC_DAIFMT_CBM_CFS: 393 case SND_SOC_DAIFMT_CBM_CFM: 394 bit_clock_master = false; 395 break; 396 default: 397 return -EINVAL; 398 } 399 400 /* Check if CPU is frame sync master */ 401 switch (dev->fmt & SND_SOC_DAIFMT_MASTER_MASK) { 402 case SND_SOC_DAIFMT_CBS_CFS: 403 case SND_SOC_DAIFMT_CBM_CFS: 404 frame_sync_master = true; 405 break; 406 case SND_SOC_DAIFMT_CBS_CFM: 407 case SND_SOC_DAIFMT_CBM_CFM: 408 frame_sync_master = false; 409 break; 410 default: 411 return -EINVAL; 412 } 413 414 /* Clock should only be set up here if CPU is clock master */ 415 if (bit_clock_master && 416 (!dev->clk_prepared || dev->clk_rate != bclk_rate)) { 417 if (dev->clk_prepared) 418 bcm2835_i2s_stop_clock(dev); 419 420 if (dev->clk_rate != bclk_rate) { 421 ret = clk_set_rate(dev->clk, bclk_rate); 422 if (ret) 423 return ret; 424 dev->clk_rate = bclk_rate; 425 } 426 427 bcm2835_i2s_start_clock(dev); 428 } 429 430 /* Setup the frame format */ 431 format = BCM2835_I2S_CHEN; 432 433 if (data_length >= 24) 434 format |= BCM2835_I2S_CHWEX; 435 436 format |= BCM2835_I2S_CHWID((data_length-8)&0xf); 437 438 /* CH2 format is the same as for CH1 */ 439 format = BCM2835_I2S_CH1(format) | BCM2835_I2S_CH2(format); 440 441 switch (dev->fmt & SND_SOC_DAIFMT_FORMAT_MASK) { 442 case SND_SOC_DAIFMT_I2S: 443 /* I2S mode needs an even number of slots */ 444 if (slots & 1) 445 return -EINVAL; 446 447 /* 448 * Use I2S-style logical slot numbering: even slots 449 * are in first half of frame, odd slots in second half. 450 */ 451 odd_slot_offset = slots >> 1; 452 453 /* MSB starts one cycle after frame start */ 454 data_delay = 1; 455 456 /* Setup frame sync signal for 50% duty cycle */ 457 framesync_length = frame_length / 2; 458 frame_start_falling_edge = true; 459 break; 460 case SND_SOC_DAIFMT_LEFT_J: 461 if (slots & 1) 462 return -EINVAL; 463 464 odd_slot_offset = slots >> 1; 465 data_delay = 0; 466 framesync_length = frame_length / 2; 467 frame_start_falling_edge = false; 468 break; 469 case SND_SOC_DAIFMT_RIGHT_J: 470 if (slots & 1) 471 return -EINVAL; 472 473 /* Odd frame lengths aren't supported */ 474 if (frame_length & 1) 475 return -EINVAL; 476 477 odd_slot_offset = slots >> 1; 478 data_delay = slot_width - data_length; 479 framesync_length = frame_length / 2; 480 frame_start_falling_edge = false; 481 break; 482 case SND_SOC_DAIFMT_DSP_A: 483 data_delay = 1; 484 framesync_length = 1; 485 frame_start_falling_edge = false; 486 break; 487 case SND_SOC_DAIFMT_DSP_B: 488 data_delay = 0; 489 framesync_length = 1; 490 frame_start_falling_edge = false; 491 break; 492 default: 493 return -EINVAL; 494 } 495 496 bcm2835_i2s_calc_channel_pos(&rx_ch1_pos, &rx_ch2_pos, 497 rx_mask, slot_width, data_delay, odd_slot_offset); 498 bcm2835_i2s_calc_channel_pos(&tx_ch1_pos, &tx_ch2_pos, 499 tx_mask, slot_width, data_delay, odd_slot_offset); 500 501 /* 502 * Transmitting data immediately after frame start, eg 503 * in left-justified or DSP mode A, only works stable 504 * if bcm2835 is the frame clock master. 505 */ 506 if ((!rx_ch1_pos || !tx_ch1_pos) && !frame_sync_master) 507 dev_warn(dev->dev, 508 "Unstable slave config detected, L/R may be swapped"); 509 510 /* 511 * Set format for both streams. 512 * We cannot set another frame length 513 * (and therefore word length) anyway, 514 * so the format will be the same. 515 */ 516 regmap_write(dev->i2s_regmap, BCM2835_I2S_RXC_A_REG, 517 format 518 | BCM2835_I2S_CH1_POS(rx_ch1_pos) 519 | BCM2835_I2S_CH2_POS(rx_ch2_pos)); 520 regmap_write(dev->i2s_regmap, BCM2835_I2S_TXC_A_REG, 521 format 522 | BCM2835_I2S_CH1_POS(tx_ch1_pos) 523 | BCM2835_I2S_CH2_POS(tx_ch2_pos)); 524 525 /* Setup the I2S mode */ 526 527 if (data_length <= 16) { 528 /* 529 * Use frame packed mode (2 channels per 32 bit word) 530 * We cannot set another frame length in the second stream 531 * (and therefore word length) anyway, 532 * so the format will be the same. 533 */ 534 mode |= BCM2835_I2S_FTXP | BCM2835_I2S_FRXP; 535 } 536 537 mode |= BCM2835_I2S_FLEN(frame_length - 1); 538 mode |= BCM2835_I2S_FSLEN(framesync_length); 539 540 /* CLKM selects bcm2835 clock slave mode */ 541 if (!bit_clock_master) 542 mode |= BCM2835_I2S_CLKM; 543 544 /* FSM selects bcm2835 frame sync slave mode */ 545 if (!frame_sync_master) 546 mode |= BCM2835_I2S_FSM; 547 548 /* CLKI selects normal clocking mode, sampling on rising edge */ 549 switch (dev->fmt & SND_SOC_DAIFMT_INV_MASK) { 550 case SND_SOC_DAIFMT_NB_NF: 551 case SND_SOC_DAIFMT_NB_IF: 552 mode |= BCM2835_I2S_CLKI; 553 break; 554 case SND_SOC_DAIFMT_IB_NF: 555 case SND_SOC_DAIFMT_IB_IF: 556 break; 557 default: 558 return -EINVAL; 559 } 560 561 /* FSI selects frame start on falling edge */ 562 switch (dev->fmt & SND_SOC_DAIFMT_INV_MASK) { 563 case SND_SOC_DAIFMT_NB_NF: 564 case SND_SOC_DAIFMT_IB_NF: 565 if (frame_start_falling_edge) 566 mode |= BCM2835_I2S_FSI; 567 break; 568 case SND_SOC_DAIFMT_NB_IF: 569 case SND_SOC_DAIFMT_IB_IF: 570 if (!frame_start_falling_edge) 571 mode |= BCM2835_I2S_FSI; 572 break; 573 default: 574 return -EINVAL; 575 } 576 577 regmap_write(dev->i2s_regmap, BCM2835_I2S_MODE_A_REG, mode); 578 579 /* Setup the DMA parameters */ 580 regmap_update_bits(dev->i2s_regmap, BCM2835_I2S_CS_A_REG, 581 BCM2835_I2S_RXTHR(1) 582 | BCM2835_I2S_TXTHR(1) 583 | BCM2835_I2S_DMAEN, 0xffffffff); 584 585 regmap_update_bits(dev->i2s_regmap, BCM2835_I2S_DREQ_A_REG, 586 BCM2835_I2S_TX_PANIC(0x10) 587 | BCM2835_I2S_RX_PANIC(0x30) 588 | BCM2835_I2S_TX(0x30) 589 | BCM2835_I2S_RX(0x20), 0xffffffff); 590 591 /* Clear FIFOs */ 592 bcm2835_i2s_clear_fifos(dev, true, true); 593 594 dev_dbg(dev->dev, 595 "slots: %d width: %d rx mask: 0x%02x tx_mask: 0x%02x\n", 596 slots, slot_width, rx_mask, tx_mask); 597 598 dev_dbg(dev->dev, "frame len: %d sync len: %d data len: %d\n", 599 frame_length, framesync_length, data_length); 600 601 dev_dbg(dev->dev, "rx pos: %d,%d tx pos: %d,%d\n", 602 rx_ch1_pos, rx_ch2_pos, tx_ch1_pos, tx_ch2_pos); 603 604 dev_dbg(dev->dev, "sampling rate: %d bclk rate: %d\n", 605 params_rate(params), bclk_rate); 606 607 dev_dbg(dev->dev, "CLKM: %d CLKI: %d FSM: %d FSI: %d frame start: %s edge\n", 608 !!(mode & BCM2835_I2S_CLKM), 609 !!(mode & BCM2835_I2S_CLKI), 610 !!(mode & BCM2835_I2S_FSM), 611 !!(mode & BCM2835_I2S_FSI), 612 (mode & BCM2835_I2S_FSI) ? "falling" : "rising"); 613 614 return ret; 615 } 616 617 static int bcm2835_i2s_prepare(struct snd_pcm_substream *substream, 618 struct snd_soc_dai *dai) 619 { 620 struct bcm2835_i2s_dev *dev = snd_soc_dai_get_drvdata(dai); 621 uint32_t cs_reg; 622 623 /* 624 * Clear both FIFOs if the one that should be started 625 * is not empty at the moment. This should only happen 626 * after overrun. Otherwise, hw_params would have cleared 627 * the FIFO. 628 */ 629 regmap_read(dev->i2s_regmap, BCM2835_I2S_CS_A_REG, &cs_reg); 630 631 if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK 632 && !(cs_reg & BCM2835_I2S_TXE)) 633 bcm2835_i2s_clear_fifos(dev, true, false); 634 else if (substream->stream == SNDRV_PCM_STREAM_CAPTURE 635 && (cs_reg & BCM2835_I2S_RXD)) 636 bcm2835_i2s_clear_fifos(dev, false, true); 637 638 return 0; 639 } 640 641 static void bcm2835_i2s_stop(struct bcm2835_i2s_dev *dev, 642 struct snd_pcm_substream *substream, 643 struct snd_soc_dai *dai) 644 { 645 uint32_t mask; 646 647 if (substream->stream == SNDRV_PCM_STREAM_CAPTURE) 648 mask = BCM2835_I2S_RXON; 649 else 650 mask = BCM2835_I2S_TXON; 651 652 regmap_update_bits(dev->i2s_regmap, 653 BCM2835_I2S_CS_A_REG, mask, 0); 654 655 /* Stop also the clock when not SND_SOC_DAIFMT_CONT */ 656 if (!dai->active && !(dev->fmt & SND_SOC_DAIFMT_CONT)) 657 bcm2835_i2s_stop_clock(dev); 658 } 659 660 static int bcm2835_i2s_trigger(struct snd_pcm_substream *substream, int cmd, 661 struct snd_soc_dai *dai) 662 { 663 struct bcm2835_i2s_dev *dev = snd_soc_dai_get_drvdata(dai); 664 uint32_t mask; 665 666 switch (cmd) { 667 case SNDRV_PCM_TRIGGER_START: 668 case SNDRV_PCM_TRIGGER_RESUME: 669 case SNDRV_PCM_TRIGGER_PAUSE_RELEASE: 670 bcm2835_i2s_start_clock(dev); 671 672 if (substream->stream == SNDRV_PCM_STREAM_CAPTURE) 673 mask = BCM2835_I2S_RXON; 674 else 675 mask = BCM2835_I2S_TXON; 676 677 regmap_update_bits(dev->i2s_regmap, 678 BCM2835_I2S_CS_A_REG, mask, mask); 679 break; 680 681 case SNDRV_PCM_TRIGGER_STOP: 682 case SNDRV_PCM_TRIGGER_SUSPEND: 683 case SNDRV_PCM_TRIGGER_PAUSE_PUSH: 684 bcm2835_i2s_stop(dev, substream, dai); 685 break; 686 default: 687 return -EINVAL; 688 } 689 690 return 0; 691 } 692 693 static int bcm2835_i2s_startup(struct snd_pcm_substream *substream, 694 struct snd_soc_dai *dai) 695 { 696 struct bcm2835_i2s_dev *dev = snd_soc_dai_get_drvdata(dai); 697 698 if (dai->active) 699 return 0; 700 701 /* Should this still be running stop it */ 702 bcm2835_i2s_stop_clock(dev); 703 704 /* Enable PCM block */ 705 regmap_update_bits(dev->i2s_regmap, BCM2835_I2S_CS_A_REG, 706 BCM2835_I2S_EN, BCM2835_I2S_EN); 707 708 /* 709 * Disable STBY. 710 * Requires at least 4 PCM clock cycles to take effect. 711 */ 712 regmap_update_bits(dev->i2s_regmap, BCM2835_I2S_CS_A_REG, 713 BCM2835_I2S_STBY, BCM2835_I2S_STBY); 714 715 return 0; 716 } 717 718 static void bcm2835_i2s_shutdown(struct snd_pcm_substream *substream, 719 struct snd_soc_dai *dai) 720 { 721 struct bcm2835_i2s_dev *dev = snd_soc_dai_get_drvdata(dai); 722 723 bcm2835_i2s_stop(dev, substream, dai); 724 725 /* If both streams are stopped, disable module and clock */ 726 if (dai->active) 727 return; 728 729 /* Disable the module */ 730 regmap_update_bits(dev->i2s_regmap, BCM2835_I2S_CS_A_REG, 731 BCM2835_I2S_EN, 0); 732 733 /* 734 * Stopping clock is necessary, because stop does 735 * not stop the clock when SND_SOC_DAIFMT_CONT 736 */ 737 bcm2835_i2s_stop_clock(dev); 738 } 739 740 static const struct snd_soc_dai_ops bcm2835_i2s_dai_ops = { 741 .startup = bcm2835_i2s_startup, 742 .shutdown = bcm2835_i2s_shutdown, 743 .prepare = bcm2835_i2s_prepare, 744 .trigger = bcm2835_i2s_trigger, 745 .hw_params = bcm2835_i2s_hw_params, 746 .set_fmt = bcm2835_i2s_set_dai_fmt, 747 .set_bclk_ratio = bcm2835_i2s_set_dai_bclk_ratio, 748 .set_tdm_slot = bcm2835_i2s_set_dai_tdm_slot, 749 }; 750 751 static int bcm2835_i2s_dai_probe(struct snd_soc_dai *dai) 752 { 753 struct bcm2835_i2s_dev *dev = snd_soc_dai_get_drvdata(dai); 754 755 snd_soc_dai_init_dma_data(dai, 756 &dev->dma_data[SNDRV_PCM_STREAM_PLAYBACK], 757 &dev->dma_data[SNDRV_PCM_STREAM_CAPTURE]); 758 759 return 0; 760 } 761 762 static struct snd_soc_dai_driver bcm2835_i2s_dai = { 763 .name = "bcm2835-i2s", 764 .probe = bcm2835_i2s_dai_probe, 765 .playback = { 766 .channels_min = 2, 767 .channels_max = 2, 768 .rates = SNDRV_PCM_RATE_CONTINUOUS, 769 .rate_min = 8000, 770 .rate_max = 384000, 771 .formats = SNDRV_PCM_FMTBIT_S16_LE 772 | SNDRV_PCM_FMTBIT_S24_LE 773 | SNDRV_PCM_FMTBIT_S32_LE 774 }, 775 .capture = { 776 .channels_min = 2, 777 .channels_max = 2, 778 .rates = SNDRV_PCM_RATE_CONTINUOUS, 779 .rate_min = 8000, 780 .rate_max = 384000, 781 .formats = SNDRV_PCM_FMTBIT_S16_LE 782 | SNDRV_PCM_FMTBIT_S24_LE 783 | SNDRV_PCM_FMTBIT_S32_LE 784 }, 785 .ops = &bcm2835_i2s_dai_ops, 786 .symmetric_rates = 1, 787 .symmetric_samplebits = 1, 788 }; 789 790 static bool bcm2835_i2s_volatile_reg(struct device *dev, unsigned int reg) 791 { 792 switch (reg) { 793 case BCM2835_I2S_CS_A_REG: 794 case BCM2835_I2S_FIFO_A_REG: 795 case BCM2835_I2S_INTSTC_A_REG: 796 case BCM2835_I2S_GRAY_REG: 797 return true; 798 default: 799 return false; 800 }; 801 } 802 803 static bool bcm2835_i2s_precious_reg(struct device *dev, unsigned int reg) 804 { 805 switch (reg) { 806 case BCM2835_I2S_FIFO_A_REG: 807 return true; 808 default: 809 return false; 810 }; 811 } 812 813 static const struct regmap_config bcm2835_regmap_config = { 814 .reg_bits = 32, 815 .reg_stride = 4, 816 .val_bits = 32, 817 .max_register = BCM2835_I2S_GRAY_REG, 818 .precious_reg = bcm2835_i2s_precious_reg, 819 .volatile_reg = bcm2835_i2s_volatile_reg, 820 .cache_type = REGCACHE_RBTREE, 821 }; 822 823 static const struct snd_soc_component_driver bcm2835_i2s_component = { 824 .name = "bcm2835-i2s-comp", 825 }; 826 827 static int bcm2835_i2s_probe(struct platform_device *pdev) 828 { 829 struct bcm2835_i2s_dev *dev; 830 int ret; 831 struct resource *mem; 832 void __iomem *base; 833 const __be32 *addr; 834 dma_addr_t dma_base; 835 836 dev = devm_kzalloc(&pdev->dev, sizeof(*dev), 837 GFP_KERNEL); 838 if (!dev) 839 return -ENOMEM; 840 841 /* get the clock */ 842 dev->clk_prepared = false; 843 dev->clk = devm_clk_get(&pdev->dev, NULL); 844 if (IS_ERR(dev->clk)) { 845 dev_err(&pdev->dev, "could not get clk: %ld\n", 846 PTR_ERR(dev->clk)); 847 return PTR_ERR(dev->clk); 848 } 849 850 /* Request ioarea */ 851 mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); 852 base = devm_ioremap_resource(&pdev->dev, mem); 853 if (IS_ERR(base)) 854 return PTR_ERR(base); 855 856 dev->i2s_regmap = devm_regmap_init_mmio(&pdev->dev, base, 857 &bcm2835_regmap_config); 858 if (IS_ERR(dev->i2s_regmap)) 859 return PTR_ERR(dev->i2s_regmap); 860 861 /* Set the DMA address - we have to parse DT ourselves */ 862 addr = of_get_address(pdev->dev.of_node, 0, NULL, NULL); 863 if (!addr) { 864 dev_err(&pdev->dev, "could not get DMA-register address\n"); 865 return -EINVAL; 866 } 867 dma_base = be32_to_cpup(addr); 868 869 dev->dma_data[SNDRV_PCM_STREAM_PLAYBACK].addr = 870 dma_base + BCM2835_I2S_FIFO_A_REG; 871 872 dev->dma_data[SNDRV_PCM_STREAM_CAPTURE].addr = 873 dma_base + BCM2835_I2S_FIFO_A_REG; 874 875 /* Set the bus width */ 876 dev->dma_data[SNDRV_PCM_STREAM_PLAYBACK].addr_width = 877 DMA_SLAVE_BUSWIDTH_4_BYTES; 878 dev->dma_data[SNDRV_PCM_STREAM_CAPTURE].addr_width = 879 DMA_SLAVE_BUSWIDTH_4_BYTES; 880 881 /* Set burst */ 882 dev->dma_data[SNDRV_PCM_STREAM_PLAYBACK].maxburst = 2; 883 dev->dma_data[SNDRV_PCM_STREAM_CAPTURE].maxburst = 2; 884 885 /* 886 * Set the PACK flag to enable S16_LE support (2 S16_LE values 887 * packed into 32-bit transfers). 888 */ 889 dev->dma_data[SNDRV_PCM_STREAM_PLAYBACK].flags = 890 SND_DMAENGINE_PCM_DAI_FLAG_PACK; 891 dev->dma_data[SNDRV_PCM_STREAM_CAPTURE].flags = 892 SND_DMAENGINE_PCM_DAI_FLAG_PACK; 893 894 /* Store the pdev */ 895 dev->dev = &pdev->dev; 896 dev_set_drvdata(&pdev->dev, dev); 897 898 ret = devm_snd_soc_register_component(&pdev->dev, 899 &bcm2835_i2s_component, &bcm2835_i2s_dai, 1); 900 if (ret) { 901 dev_err(&pdev->dev, "Could not register DAI: %d\n", ret); 902 return ret; 903 } 904 905 ret = devm_snd_dmaengine_pcm_register(&pdev->dev, NULL, 0); 906 if (ret) { 907 dev_err(&pdev->dev, "Could not register PCM: %d\n", ret); 908 return ret; 909 } 910 911 return 0; 912 } 913 914 static const struct of_device_id bcm2835_i2s_of_match[] = { 915 { .compatible = "brcm,bcm2835-i2s", }, 916 {}, 917 }; 918 919 MODULE_DEVICE_TABLE(of, bcm2835_i2s_of_match); 920 921 static struct platform_driver bcm2835_i2s_driver = { 922 .probe = bcm2835_i2s_probe, 923 .driver = { 924 .name = "bcm2835-i2s", 925 .of_match_table = bcm2835_i2s_of_match, 926 }, 927 }; 928 929 module_platform_driver(bcm2835_i2s_driver); 930 931 MODULE_ALIAS("platform:bcm2835-i2s"); 932 MODULE_DESCRIPTION("BCM2835 I2S interface"); 933 MODULE_AUTHOR("Florian Meier <florian.meier@koalo.de>"); 934 MODULE_LICENSE("GPL v2"); 935