mchp-i2s-mcc.c (31211B)
1// SPDX-License-Identifier: GPL-2.0 2// 3// Driver for Microchip I2S Multi-channel controller 4// 5// Copyright (C) 2018 Microchip Technology Inc. and its subsidiaries 6// 7// Author: Codrin Ciubotariu <codrin.ciubotariu@microchip.com> 8 9#include <linux/init.h> 10#include <linux/module.h> 11#include <linux/device.h> 12#include <linux/slab.h> 13 14#include <linux/delay.h> 15#include <linux/io.h> 16#include <linux/clk.h> 17#include <linux/mfd/syscon.h> 18#include <linux/lcm.h> 19#include <linux/of_device.h> 20 21#include <sound/core.h> 22#include <sound/pcm.h> 23#include <sound/pcm_params.h> 24#include <sound/initval.h> 25#include <sound/soc.h> 26#include <sound/dmaengine_pcm.h> 27 28/* 29 * ---- I2S Controller Register map ---- 30 */ 31#define MCHP_I2SMCC_CR 0x0000 /* Control Register */ 32#define MCHP_I2SMCC_MRA 0x0004 /* Mode Register A */ 33#define MCHP_I2SMCC_MRB 0x0008 /* Mode Register B */ 34#define MCHP_I2SMCC_SR 0x000C /* Status Register */ 35#define MCHP_I2SMCC_IERA 0x0010 /* Interrupt Enable Register A */ 36#define MCHP_I2SMCC_IDRA 0x0014 /* Interrupt Disable Register A */ 37#define MCHP_I2SMCC_IMRA 0x0018 /* Interrupt Mask Register A */ 38#define MCHP_I2SMCC_ISRA 0X001C /* Interrupt Status Register A */ 39 40#define MCHP_I2SMCC_IERB 0x0020 /* Interrupt Enable Register B */ 41#define MCHP_I2SMCC_IDRB 0x0024 /* Interrupt Disable Register B */ 42#define MCHP_I2SMCC_IMRB 0x0028 /* Interrupt Mask Register B */ 43#define MCHP_I2SMCC_ISRB 0X002C /* Interrupt Status Register B */ 44 45#define MCHP_I2SMCC_RHR 0x0030 /* Receiver Holding Register */ 46#define MCHP_I2SMCC_THR 0x0034 /* Transmitter Holding Register */ 47 48#define MCHP_I2SMCC_RHL0R 0x0040 /* Receiver Holding Left 0 Register */ 49#define MCHP_I2SMCC_RHR0R 0x0044 /* Receiver Holding Right 0 Register */ 50 51#define MCHP_I2SMCC_RHL1R 0x0048 /* Receiver Holding Left 1 Register */ 52#define MCHP_I2SMCC_RHR1R 0x004C /* Receiver Holding Right 1 Register */ 53 54#define MCHP_I2SMCC_RHL2R 0x0050 /* Receiver Holding Left 2 Register */ 55#define MCHP_I2SMCC_RHR2R 0x0054 /* Receiver Holding Right 2 Register */ 56 57#define MCHP_I2SMCC_RHL3R 0x0058 /* Receiver Holding Left 3 Register */ 58#define MCHP_I2SMCC_RHR3R 0x005C /* Receiver Holding Right 3 Register */ 59 60#define MCHP_I2SMCC_THL0R 0x0060 /* Transmitter Holding Left 0 Register */ 61#define MCHP_I2SMCC_THR0R 0x0064 /* Transmitter Holding Right 0 Register */ 62 63#define MCHP_I2SMCC_THL1R 0x0068 /* Transmitter Holding Left 1 Register */ 64#define MCHP_I2SMCC_THR1R 0x006C /* Transmitter Holding Right 1 Register */ 65 66#define MCHP_I2SMCC_THL2R 0x0070 /* Transmitter Holding Left 2 Register */ 67#define MCHP_I2SMCC_THR2R 0x0074 /* Transmitter Holding Right 2 Register */ 68 69#define MCHP_I2SMCC_THL3R 0x0078 /* Transmitter Holding Left 3 Register */ 70#define MCHP_I2SMCC_THR3R 0x007C /* Transmitter Holding Right 3 Register */ 71 72#define MCHP_I2SMCC_VERSION 0x00FC /* Version Register */ 73 74/* 75 * ---- Control Register (Write-only) ---- 76 */ 77#define MCHP_I2SMCC_CR_RXEN BIT(0) /* Receiver Enable */ 78#define MCHP_I2SMCC_CR_RXDIS BIT(1) /* Receiver Disable */ 79#define MCHP_I2SMCC_CR_CKEN BIT(2) /* Clock Enable */ 80#define MCHP_I2SMCC_CR_CKDIS BIT(3) /* Clock Disable */ 81#define MCHP_I2SMCC_CR_TXEN BIT(4) /* Transmitter Enable */ 82#define MCHP_I2SMCC_CR_TXDIS BIT(5) /* Transmitter Disable */ 83#define MCHP_I2SMCC_CR_SWRST BIT(7) /* Software Reset */ 84 85/* 86 * ---- Mode Register A (Read/Write) ---- 87 */ 88#define MCHP_I2SMCC_MRA_MODE_MASK GENMASK(0, 0) 89#define MCHP_I2SMCC_MRA_MODE_SLAVE (0 << 0) 90#define MCHP_I2SMCC_MRA_MODE_MASTER (1 << 0) 91 92#define MCHP_I2SMCC_MRA_DATALENGTH_MASK GENMASK(3, 1) 93#define MCHP_I2SMCC_MRA_DATALENGTH_32_BITS (0 << 1) 94#define MCHP_I2SMCC_MRA_DATALENGTH_24_BITS (1 << 1) 95#define MCHP_I2SMCC_MRA_DATALENGTH_20_BITS (2 << 1) 96#define MCHP_I2SMCC_MRA_DATALENGTH_18_BITS (3 << 1) 97#define MCHP_I2SMCC_MRA_DATALENGTH_16_BITS (4 << 1) 98#define MCHP_I2SMCC_MRA_DATALENGTH_16_BITS_COMPACT (5 << 1) 99#define MCHP_I2SMCC_MRA_DATALENGTH_8_BITS (6 << 1) 100#define MCHP_I2SMCC_MRA_DATALENGTH_8_BITS_COMPACT (7 << 1) 101 102#define MCHP_I2SMCC_MRA_WIRECFG_MASK GENMASK(5, 4) 103#define MCHP_I2SMCC_MRA_WIRECFG_TDM(pin) (((pin) << 4) & \ 104 MCHP_I2SMCC_MRA_WIRECFG_MASK) 105#define MCHP_I2SMCC_MRA_WIRECFG_I2S_1_TDM_0 (0 << 4) 106#define MCHP_I2SMCC_MRA_WIRECFG_I2S_2_TDM_1 (1 << 4) 107#define MCHP_I2SMCC_MRA_WIRECFG_I2S_4_TDM_2 (2 << 4) 108#define MCHP_I2SMCC_MRA_WIRECFG_TDM_3 (3 << 4) 109 110#define MCHP_I2SMCC_MRA_FORMAT_MASK GENMASK(7, 6) 111#define MCHP_I2SMCC_MRA_FORMAT_I2S (0 << 6) 112#define MCHP_I2SMCC_MRA_FORMAT_LJ (1 << 6) /* Left Justified */ 113#define MCHP_I2SMCC_MRA_FORMAT_TDM (2 << 6) 114#define MCHP_I2SMCC_MRA_FORMAT_TDMLJ (3 << 6) 115 116/* Transmitter uses one DMA channel ... */ 117/* Left audio samples duplicated to right audio channel */ 118#define MCHP_I2SMCC_MRA_RXMONO BIT(8) 119 120/* I2SDO output of I2SC is internally connected to I2SDI input */ 121#define MCHP_I2SMCC_MRA_RXLOOP BIT(9) 122 123/* Receiver uses one DMA channel ... */ 124/* Left audio samples duplicated to right audio channel */ 125#define MCHP_I2SMCC_MRA_TXMONO BIT(10) 126 127/* x sample transmitted when underrun */ 128#define MCHP_I2SMCC_MRA_TXSAME_ZERO (0 << 11) /* Zero sample */ 129#define MCHP_I2SMCC_MRA_TXSAME_PREVIOUS (1 << 11) /* Previous sample */ 130 131/* select between peripheral clock and generated clock */ 132#define MCHP_I2SMCC_MRA_SRCCLK_PCLK (0 << 12) 133#define MCHP_I2SMCC_MRA_SRCCLK_GCLK (1 << 12) 134 135/* Number of TDM Channels - 1 */ 136#define MCHP_I2SMCC_MRA_NBCHAN_MASK GENMASK(15, 13) 137#define MCHP_I2SMCC_MRA_NBCHAN(ch) \ 138 ((((ch) - 1) << 13) & MCHP_I2SMCC_MRA_NBCHAN_MASK) 139 140/* Selected Clock to I2SMCC Master Clock ratio */ 141#define MCHP_I2SMCC_MRA_IMCKDIV_MASK GENMASK(21, 16) 142#define MCHP_I2SMCC_MRA_IMCKDIV(div) \ 143 (((div) << 16) & MCHP_I2SMCC_MRA_IMCKDIV_MASK) 144 145/* TDM Frame Synchronization */ 146#define MCHP_I2SMCC_MRA_TDMFS_MASK GENMASK(23, 22) 147#define MCHP_I2SMCC_MRA_TDMFS_SLOT (0 << 22) 148#define MCHP_I2SMCC_MRA_TDMFS_HALF (1 << 22) 149#define MCHP_I2SMCC_MRA_TDMFS_BIT (2 << 22) 150 151/* Selected Clock to I2SMC Serial Clock ratio */ 152#define MCHP_I2SMCC_MRA_ISCKDIV_MASK GENMASK(29, 24) 153#define MCHP_I2SMCC_MRA_ISCKDIV(div) \ 154 (((div) << 24) & MCHP_I2SMCC_MRA_ISCKDIV_MASK) 155 156/* Master Clock mode */ 157#define MCHP_I2SMCC_MRA_IMCKMODE_MASK GENMASK(30, 30) 158/* 0: No master clock generated*/ 159#define MCHP_I2SMCC_MRA_IMCKMODE_NONE (0 << 30) 160/* 1: master clock generated (internally generated clock drives I2SMCK pin) */ 161#define MCHP_I2SMCC_MRA_IMCKMODE_GEN (1 << 30) 162 163/* Slot Width */ 164/* 0: slot is 32 bits wide for DATALENGTH = 18/20/24 bits. */ 165/* 1: slot is 24 bits wide for DATALENGTH = 18/20/24 bits. */ 166#define MCHP_I2SMCC_MRA_IWS BIT(31) 167 168/* 169 * ---- Mode Register B (Read/Write) ---- 170 */ 171/* all enabled I2S left channels are filled first, then I2S right channels */ 172#define MCHP_I2SMCC_MRB_CRAMODE_LEFT_FIRST (0 << 0) 173/* 174 * an enabled I2S left channel is filled, then the corresponding right 175 * channel, until all channels are filled 176 */ 177#define MCHP_I2SMCC_MRB_CRAMODE_REGULAR (1 << 0) 178 179#define MCHP_I2SMCC_MRB_FIFOEN BIT(4) 180 181#define MCHP_I2SMCC_MRB_DMACHUNK_MASK GENMASK(9, 8) 182#define MCHP_I2SMCC_MRB_DMACHUNK(no_words) \ 183 (((fls(no_words) - 1) << 8) & MCHP_I2SMCC_MRB_DMACHUNK_MASK) 184 185#define MCHP_I2SMCC_MRB_CLKSEL_MASK GENMASK(16, 16) 186#define MCHP_I2SMCC_MRB_CLKSEL_EXT (0 << 16) 187#define MCHP_I2SMCC_MRB_CLKSEL_INT (1 << 16) 188 189/* 190 * ---- Status Registers (Read-only) ---- 191 */ 192#define MCHP_I2SMCC_SR_RXEN BIT(0) /* Receiver Enabled */ 193#define MCHP_I2SMCC_SR_TXEN BIT(4) /* Transmitter Enabled */ 194 195/* 196 * ---- Interrupt Enable/Disable/Mask/Status Registers A ---- 197 */ 198#define MCHP_I2SMCC_INT_TXRDY_MASK(ch) GENMASK((ch) - 1, 0) 199#define MCHP_I2SMCC_INT_TXRDYCH(ch) BIT(ch) 200#define MCHP_I2SMCC_INT_TXUNF_MASK(ch) GENMASK((ch) + 7, 8) 201#define MCHP_I2SMCC_INT_TXUNFCH(ch) BIT((ch) + 8) 202#define MCHP_I2SMCC_INT_RXRDY_MASK(ch) GENMASK((ch) + 15, 16) 203#define MCHP_I2SMCC_INT_RXRDYCH(ch) BIT((ch) + 16) 204#define MCHP_I2SMCC_INT_RXOVF_MASK(ch) GENMASK((ch) + 23, 24) 205#define MCHP_I2SMCC_INT_RXOVFCH(ch) BIT((ch) + 24) 206 207/* 208 * ---- Interrupt Enable/Disable/Mask/Status Registers B ---- 209 */ 210#define MCHP_I2SMCC_INT_WERR BIT(0) 211#define MCHP_I2SMCC_INT_TXFFRDY BIT(8) 212#define MCHP_I2SMCC_INT_TXFFEMP BIT(9) 213#define MCHP_I2SMCC_INT_RXFFRDY BIT(12) 214#define MCHP_I2SMCC_INT_RXFFFUL BIT(13) 215 216/* 217 * ---- Version Register (Read-only) ---- 218 */ 219#define MCHP_I2SMCC_VERSION_MASK GENMASK(11, 0) 220 221#define MCHP_I2SMCC_MAX_CHANNELS 8 222#define MCHP_I2MCC_TDM_SLOT_WIDTH 32 223 224static const struct regmap_config mchp_i2s_mcc_regmap_config = { 225 .reg_bits = 32, 226 .reg_stride = 4, 227 .val_bits = 32, 228 .max_register = MCHP_I2SMCC_VERSION, 229}; 230 231struct mchp_i2s_mcc_soc_data { 232 unsigned int data_pin_pair_num; 233 bool has_fifo; 234}; 235 236struct mchp_i2s_mcc_dev { 237 struct wait_queue_head wq_txrdy; 238 struct wait_queue_head wq_rxrdy; 239 struct device *dev; 240 struct regmap *regmap; 241 struct clk *pclk; 242 struct clk *gclk; 243 const struct mchp_i2s_mcc_soc_data *soc; 244 struct snd_dmaengine_dai_dma_data playback; 245 struct snd_dmaengine_dai_dma_data capture; 246 unsigned int fmt; 247 unsigned int sysclk; 248 unsigned int frame_length; 249 int tdm_slots; 250 int channels; 251 u8 tdm_data_pair; 252 unsigned int gclk_use:1; 253 unsigned int gclk_running:1; 254 unsigned int tx_rdy:1; 255 unsigned int rx_rdy:1; 256}; 257 258static irqreturn_t mchp_i2s_mcc_interrupt(int irq, void *dev_id) 259{ 260 struct mchp_i2s_mcc_dev *dev = dev_id; 261 u32 sra, imra, srb, imrb, pendinga, pendingb, idra = 0, idrb = 0; 262 irqreturn_t ret = IRQ_NONE; 263 264 regmap_read(dev->regmap, MCHP_I2SMCC_IMRA, &imra); 265 regmap_read(dev->regmap, MCHP_I2SMCC_ISRA, &sra); 266 pendinga = imra & sra; 267 268 regmap_read(dev->regmap, MCHP_I2SMCC_IMRB, &imrb); 269 regmap_read(dev->regmap, MCHP_I2SMCC_ISRB, &srb); 270 pendingb = imrb & srb; 271 272 if (!pendinga && !pendingb) 273 return IRQ_NONE; 274 275 /* 276 * Tx/Rx ready interrupts are enabled when stopping only, to assure 277 * availability and to disable clocks if necessary 278 */ 279 if (dev->soc->has_fifo) { 280 idrb |= pendingb & (MCHP_I2SMCC_INT_TXFFRDY | 281 MCHP_I2SMCC_INT_RXFFRDY); 282 } else { 283 idra |= pendinga & (MCHP_I2SMCC_INT_TXRDY_MASK(dev->channels) | 284 MCHP_I2SMCC_INT_RXRDY_MASK(dev->channels)); 285 } 286 if (idra || idrb) 287 ret = IRQ_HANDLED; 288 289 if ((!dev->soc->has_fifo && 290 (imra & MCHP_I2SMCC_INT_TXRDY_MASK(dev->channels)) && 291 (imra & MCHP_I2SMCC_INT_TXRDY_MASK(dev->channels)) == 292 (idra & MCHP_I2SMCC_INT_TXRDY_MASK(dev->channels))) || 293 (dev->soc->has_fifo && imrb & MCHP_I2SMCC_INT_TXFFRDY)) { 294 dev->tx_rdy = 1; 295 wake_up_interruptible(&dev->wq_txrdy); 296 } 297 if ((!dev->soc->has_fifo && 298 (imra & MCHP_I2SMCC_INT_RXRDY_MASK(dev->channels)) && 299 (imra & MCHP_I2SMCC_INT_RXRDY_MASK(dev->channels)) == 300 (idra & MCHP_I2SMCC_INT_RXRDY_MASK(dev->channels))) || 301 (dev->soc->has_fifo && imrb & MCHP_I2SMCC_INT_RXFFRDY)) { 302 dev->rx_rdy = 1; 303 wake_up_interruptible(&dev->wq_rxrdy); 304 } 305 if (dev->soc->has_fifo) 306 regmap_write(dev->regmap, MCHP_I2SMCC_IDRB, idrb); 307 else 308 regmap_write(dev->regmap, MCHP_I2SMCC_IDRA, idra); 309 310 return ret; 311} 312 313static int mchp_i2s_mcc_set_sysclk(struct snd_soc_dai *dai, 314 int clk_id, unsigned int freq, int dir) 315{ 316 struct mchp_i2s_mcc_dev *dev = snd_soc_dai_get_drvdata(dai); 317 318 dev_dbg(dev->dev, "%s() clk_id=%d freq=%u dir=%d\n", 319 __func__, clk_id, freq, dir); 320 321 /* We do not need SYSCLK */ 322 if (dir == SND_SOC_CLOCK_IN) 323 return 0; 324 325 dev->sysclk = freq; 326 327 return 0; 328} 329 330static int mchp_i2s_mcc_set_bclk_ratio(struct snd_soc_dai *dai, 331 unsigned int ratio) 332{ 333 struct mchp_i2s_mcc_dev *dev = snd_soc_dai_get_drvdata(dai); 334 335 dev_dbg(dev->dev, "%s() ratio=%u\n", __func__, ratio); 336 337 dev->frame_length = ratio; 338 339 return 0; 340} 341 342static int mchp_i2s_mcc_set_dai_fmt(struct snd_soc_dai *dai, unsigned int fmt) 343{ 344 struct mchp_i2s_mcc_dev *dev = snd_soc_dai_get_drvdata(dai); 345 346 dev_dbg(dev->dev, "%s() fmt=%#x\n", __func__, fmt); 347 348 /* We don't support any kind of clock inversion */ 349 if ((fmt & SND_SOC_DAIFMT_INV_MASK) != SND_SOC_DAIFMT_NB_NF) 350 return -EINVAL; 351 352 /* We can't generate only FSYNC */ 353 if ((fmt & SND_SOC_DAIFMT_CLOCK_PROVIDER_MASK) == SND_SOC_DAIFMT_CBP_CFC) 354 return -EINVAL; 355 356 /* We can only reconfigure the IP when it's stopped */ 357 if (fmt & SND_SOC_DAIFMT_CONT) 358 return -EINVAL; 359 360 dev->fmt = fmt; 361 362 return 0; 363} 364 365static int mchp_i2s_mcc_set_dai_tdm_slot(struct snd_soc_dai *dai, 366 unsigned int tx_mask, 367 unsigned int rx_mask, 368 int slots, int slot_width) 369{ 370 struct mchp_i2s_mcc_dev *dev = snd_soc_dai_get_drvdata(dai); 371 372 dev_dbg(dev->dev, 373 "%s() tx_mask=0x%08x rx_mask=0x%08x slots=%d width=%d\n", 374 __func__, tx_mask, rx_mask, slots, slot_width); 375 376 if (slots < 0 || slots > MCHP_I2SMCC_MAX_CHANNELS || 377 slot_width != MCHP_I2MCC_TDM_SLOT_WIDTH) 378 return -EINVAL; 379 380 if (slots) { 381 /* We do not support daisy chain */ 382 if (rx_mask != GENMASK(slots - 1, 0) || 383 rx_mask != tx_mask) 384 return -EINVAL; 385 } 386 387 dev->tdm_slots = slots; 388 dev->frame_length = slots * MCHP_I2MCC_TDM_SLOT_WIDTH; 389 390 return 0; 391} 392 393static int mchp_i2s_mcc_clk_get_rate_diff(struct clk *clk, 394 unsigned long rate, 395 struct clk **best_clk, 396 unsigned long *best_rate, 397 unsigned long *best_diff_rate) 398{ 399 long round_rate; 400 unsigned int diff_rate; 401 402 round_rate = clk_round_rate(clk, rate); 403 if (round_rate < 0) 404 return (int)round_rate; 405 406 diff_rate = abs(rate - round_rate); 407 if (diff_rate < *best_diff_rate) { 408 *best_clk = clk; 409 *best_diff_rate = diff_rate; 410 *best_rate = rate; 411 } 412 413 return 0; 414} 415 416static int mchp_i2s_mcc_config_divs(struct mchp_i2s_mcc_dev *dev, 417 unsigned int bclk, unsigned int *mra, 418 unsigned long *best_rate) 419{ 420 unsigned long clk_rate; 421 unsigned long lcm_rate; 422 unsigned long best_diff_rate = ~0; 423 unsigned int sysclk; 424 struct clk *best_clk = NULL; 425 int ret; 426 427 /* For code simplification */ 428 if (!dev->sysclk) 429 sysclk = bclk; 430 else 431 sysclk = dev->sysclk; 432 433 /* 434 * MCLK is Selected CLK / (2 * IMCKDIV), 435 * BCLK is Selected CLK / (2 * ISCKDIV); 436 * if IMCKDIV or ISCKDIV are 0, MCLK or BCLK = Selected CLK 437 */ 438 lcm_rate = lcm(sysclk, bclk); 439 if ((lcm_rate / sysclk % 2 == 1 && lcm_rate / sysclk > 2) || 440 (lcm_rate / bclk % 2 == 1 && lcm_rate / bclk > 2)) 441 lcm_rate *= 2; 442 443 for (clk_rate = lcm_rate; 444 (clk_rate == sysclk || clk_rate / (sysclk * 2) <= GENMASK(5, 0)) && 445 (clk_rate == bclk || clk_rate / (bclk * 2) <= GENMASK(5, 0)); 446 clk_rate += lcm_rate) { 447 ret = mchp_i2s_mcc_clk_get_rate_diff(dev->gclk, clk_rate, 448 &best_clk, best_rate, 449 &best_diff_rate); 450 if (ret) { 451 dev_err(dev->dev, "gclk error for rate %lu: %d", 452 clk_rate, ret); 453 } else { 454 if (!best_diff_rate) { 455 dev_dbg(dev->dev, "found perfect rate on gclk: %lu\n", 456 clk_rate); 457 break; 458 } 459 } 460 461 ret = mchp_i2s_mcc_clk_get_rate_diff(dev->pclk, clk_rate, 462 &best_clk, best_rate, 463 &best_diff_rate); 464 if (ret) { 465 dev_err(dev->dev, "pclk error for rate %lu: %d", 466 clk_rate, ret); 467 } else { 468 if (!best_diff_rate) { 469 dev_dbg(dev->dev, "found perfect rate on pclk: %lu\n", 470 clk_rate); 471 break; 472 } 473 } 474 } 475 476 /* check if clocks returned only errors */ 477 if (!best_clk) { 478 dev_err(dev->dev, "unable to change rate to clocks\n"); 479 return -EINVAL; 480 } 481 482 dev_dbg(dev->dev, "source CLK is %s with rate %lu, diff %lu\n", 483 best_clk == dev->pclk ? "pclk" : "gclk", 484 *best_rate, best_diff_rate); 485 486 /* Configure divisors */ 487 if (dev->sysclk) 488 *mra |= MCHP_I2SMCC_MRA_IMCKDIV(*best_rate / (2 * sysclk)); 489 *mra |= MCHP_I2SMCC_MRA_ISCKDIV(*best_rate / (2 * bclk)); 490 491 if (best_clk == dev->gclk) 492 *mra |= MCHP_I2SMCC_MRA_SRCCLK_GCLK; 493 else 494 *mra |= MCHP_I2SMCC_MRA_SRCCLK_PCLK; 495 496 return 0; 497} 498 499static int mchp_i2s_mcc_is_running(struct mchp_i2s_mcc_dev *dev) 500{ 501 u32 sr; 502 503 regmap_read(dev->regmap, MCHP_I2SMCC_SR, &sr); 504 return !!(sr & (MCHP_I2SMCC_SR_TXEN | MCHP_I2SMCC_SR_RXEN)); 505} 506 507static int mchp_i2s_mcc_hw_params(struct snd_pcm_substream *substream, 508 struct snd_pcm_hw_params *params, 509 struct snd_soc_dai *dai) 510{ 511 unsigned long rate = 0; 512 struct mchp_i2s_mcc_dev *dev = snd_soc_dai_get_drvdata(dai); 513 u32 mra = 0; 514 u32 mrb = 0; 515 unsigned int channels = params_channels(params); 516 unsigned int frame_length = dev->frame_length; 517 unsigned int bclk_rate; 518 int set_divs = 0; 519 int ret; 520 bool is_playback = (substream->stream == SNDRV_PCM_STREAM_PLAYBACK); 521 522 dev_dbg(dev->dev, "%s() rate=%u format=%#x width=%u channels=%u\n", 523 __func__, params_rate(params), params_format(params), 524 params_width(params), params_channels(params)); 525 526 switch (dev->fmt & SND_SOC_DAIFMT_FORMAT_MASK) { 527 case SND_SOC_DAIFMT_I2S: 528 if (dev->tdm_slots) { 529 dev_err(dev->dev, "I2S with TDM is not supported\n"); 530 return -EINVAL; 531 } 532 mra |= MCHP_I2SMCC_MRA_FORMAT_I2S; 533 break; 534 case SND_SOC_DAIFMT_LEFT_J: 535 if (dev->tdm_slots) { 536 dev_err(dev->dev, "Left-Justified with TDM is not supported\n"); 537 return -EINVAL; 538 } 539 mra |= MCHP_I2SMCC_MRA_FORMAT_LJ; 540 break; 541 case SND_SOC_DAIFMT_DSP_A: 542 mra |= MCHP_I2SMCC_MRA_FORMAT_TDM; 543 break; 544 default: 545 dev_err(dev->dev, "unsupported bus format\n"); 546 return -EINVAL; 547 } 548 549 switch (dev->fmt & SND_SOC_DAIFMT_CLOCK_PROVIDER_MASK) { 550 case SND_SOC_DAIFMT_CBC_CFC: 551 /* cpu is BCLK and LRC master */ 552 mra |= MCHP_I2SMCC_MRA_MODE_MASTER; 553 if (dev->sysclk) 554 mra |= MCHP_I2SMCC_MRA_IMCKMODE_GEN; 555 set_divs = 1; 556 break; 557 case SND_SOC_DAIFMT_CBC_CFP: 558 /* cpu is BCLK master */ 559 mrb |= MCHP_I2SMCC_MRB_CLKSEL_INT; 560 set_divs = 1; 561 fallthrough; 562 case SND_SOC_DAIFMT_CBP_CFP: 563 /* cpu is slave */ 564 mra |= MCHP_I2SMCC_MRA_MODE_SLAVE; 565 if (dev->sysclk) 566 dev_warn(dev->dev, "Unable to generate MCLK in Slave mode\n"); 567 break; 568 default: 569 dev_err(dev->dev, "unsupported master/slave mode\n"); 570 return -EINVAL; 571 } 572 573 if (dev->fmt & (SND_SOC_DAIFMT_I2S | SND_SOC_DAIFMT_LEFT_J)) { 574 /* for I2S and LEFT_J one pin is needed for every 2 channels */ 575 if (channels > dev->soc->data_pin_pair_num * 2) { 576 dev_err(dev->dev, 577 "unsupported number of audio channels: %d\n", 578 channels); 579 return -EINVAL; 580 } 581 582 /* enable for interleaved format */ 583 mrb |= MCHP_I2SMCC_MRB_CRAMODE_REGULAR; 584 585 switch (channels) { 586 case 1: 587 if (is_playback) 588 mra |= MCHP_I2SMCC_MRA_TXMONO; 589 else 590 mra |= MCHP_I2SMCC_MRA_RXMONO; 591 break; 592 case 2: 593 break; 594 case 4: 595 mra |= MCHP_I2SMCC_MRA_WIRECFG_I2S_2_TDM_1; 596 break; 597 case 8: 598 mra |= MCHP_I2SMCC_MRA_WIRECFG_I2S_4_TDM_2; 599 break; 600 default: 601 dev_err(dev->dev, "unsupported number of audio channels\n"); 602 return -EINVAL; 603 } 604 605 if (!frame_length) 606 frame_length = 2 * params_physical_width(params); 607 } else if (dev->fmt & SND_SOC_DAIFMT_DSP_A) { 608 mra |= MCHP_I2SMCC_MRA_WIRECFG_TDM(dev->tdm_data_pair); 609 610 if (dev->tdm_slots) { 611 if (channels % 2 && channels * 2 <= dev->tdm_slots) { 612 /* 613 * Duplicate data for even-numbered channels 614 * to odd-numbered channels 615 */ 616 if (is_playback) 617 mra |= MCHP_I2SMCC_MRA_TXMONO; 618 else 619 mra |= MCHP_I2SMCC_MRA_RXMONO; 620 } 621 channels = dev->tdm_slots; 622 } 623 624 mra |= MCHP_I2SMCC_MRA_NBCHAN(channels); 625 if (!frame_length) 626 frame_length = channels * MCHP_I2MCC_TDM_SLOT_WIDTH; 627 } 628 629 /* 630 * We must have the same burst size configured 631 * in the DMA transfer and in out IP 632 */ 633 mrb |= MCHP_I2SMCC_MRB_DMACHUNK(channels); 634 if (is_playback) 635 dev->playback.maxburst = 1 << (fls(channels) - 1); 636 else 637 dev->capture.maxburst = 1 << (fls(channels) - 1); 638 639 switch (params_format(params)) { 640 case SNDRV_PCM_FORMAT_S8: 641 mra |= MCHP_I2SMCC_MRA_DATALENGTH_8_BITS; 642 break; 643 case SNDRV_PCM_FORMAT_S16_LE: 644 mra |= MCHP_I2SMCC_MRA_DATALENGTH_16_BITS; 645 break; 646 case SNDRV_PCM_FORMAT_S18_3LE: 647 mra |= MCHP_I2SMCC_MRA_DATALENGTH_18_BITS | 648 MCHP_I2SMCC_MRA_IWS; 649 break; 650 case SNDRV_PCM_FORMAT_S20_3LE: 651 mra |= MCHP_I2SMCC_MRA_DATALENGTH_20_BITS | 652 MCHP_I2SMCC_MRA_IWS; 653 break; 654 case SNDRV_PCM_FORMAT_S24_3LE: 655 mra |= MCHP_I2SMCC_MRA_DATALENGTH_24_BITS | 656 MCHP_I2SMCC_MRA_IWS; 657 break; 658 case SNDRV_PCM_FORMAT_S24_LE: 659 mra |= MCHP_I2SMCC_MRA_DATALENGTH_24_BITS; 660 break; 661 case SNDRV_PCM_FORMAT_S32_LE: 662 mra |= MCHP_I2SMCC_MRA_DATALENGTH_32_BITS; 663 break; 664 default: 665 dev_err(dev->dev, "unsupported size/endianness for audio samples\n"); 666 return -EINVAL; 667 } 668 669 if (set_divs) { 670 bclk_rate = frame_length * params_rate(params); 671 ret = mchp_i2s_mcc_config_divs(dev, bclk_rate, &mra, 672 &rate); 673 if (ret) { 674 dev_err(dev->dev, 675 "unable to configure the divisors: %d\n", ret); 676 return ret; 677 } 678 } 679 680 /* enable FIFO if available */ 681 if (dev->soc->has_fifo) 682 mrb |= MCHP_I2SMCC_MRB_FIFOEN; 683 684 /* 685 * If we are already running, the wanted setup must be 686 * the same with the one that's currently ongoing 687 */ 688 if (mchp_i2s_mcc_is_running(dev)) { 689 u32 mra_cur; 690 u32 mrb_cur; 691 692 regmap_read(dev->regmap, MCHP_I2SMCC_MRA, &mra_cur); 693 regmap_read(dev->regmap, MCHP_I2SMCC_MRB, &mrb_cur); 694 if (mra != mra_cur || mrb != mrb_cur) 695 return -EINVAL; 696 697 return 0; 698 } 699 700 if (mra & MCHP_I2SMCC_MRA_SRCCLK_GCLK && !dev->gclk_use) { 701 /* set the rate */ 702 ret = clk_set_rate(dev->gclk, rate); 703 if (ret) { 704 dev_err(dev->dev, 705 "unable to set rate %lu to GCLK: %d\n", 706 rate, ret); 707 return ret; 708 } 709 710 ret = clk_prepare(dev->gclk); 711 if (ret < 0) { 712 dev_err(dev->dev, "unable to prepare GCLK: %d\n", ret); 713 return ret; 714 } 715 dev->gclk_use = 1; 716 } 717 718 /* Save the number of channels to know what interrupts to enable */ 719 dev->channels = channels; 720 721 ret = regmap_write(dev->regmap, MCHP_I2SMCC_MRA, mra); 722 if (ret < 0) { 723 if (dev->gclk_use) { 724 clk_unprepare(dev->gclk); 725 dev->gclk_use = 0; 726 } 727 return ret; 728 } 729 return regmap_write(dev->regmap, MCHP_I2SMCC_MRB, mrb); 730} 731 732static int mchp_i2s_mcc_hw_free(struct snd_pcm_substream *substream, 733 struct snd_soc_dai *dai) 734{ 735 struct mchp_i2s_mcc_dev *dev = snd_soc_dai_get_drvdata(dai); 736 bool is_playback = (substream->stream == SNDRV_PCM_STREAM_PLAYBACK); 737 long err; 738 739 if (is_playback) { 740 err = wait_event_interruptible_timeout(dev->wq_txrdy, 741 dev->tx_rdy, 742 msecs_to_jiffies(500)); 743 if (err == 0) { 744 dev_warn_once(dev->dev, 745 "Timeout waiting for Tx ready\n"); 746 if (dev->soc->has_fifo) 747 regmap_write(dev->regmap, MCHP_I2SMCC_IDRB, 748 MCHP_I2SMCC_INT_TXFFRDY); 749 else 750 regmap_write(dev->regmap, MCHP_I2SMCC_IDRA, 751 MCHP_I2SMCC_INT_TXRDY_MASK(dev->channels)); 752 753 dev->tx_rdy = 1; 754 } 755 } else { 756 err = wait_event_interruptible_timeout(dev->wq_rxrdy, 757 dev->rx_rdy, 758 msecs_to_jiffies(500)); 759 if (err == 0) { 760 dev_warn_once(dev->dev, 761 "Timeout waiting for Rx ready\n"); 762 if (dev->soc->has_fifo) 763 regmap_write(dev->regmap, MCHP_I2SMCC_IDRB, 764 MCHP_I2SMCC_INT_RXFFRDY); 765 else 766 regmap_write(dev->regmap, MCHP_I2SMCC_IDRA, 767 MCHP_I2SMCC_INT_RXRDY_MASK(dev->channels)); 768 dev->rx_rdy = 1; 769 } 770 } 771 772 if (!mchp_i2s_mcc_is_running(dev)) { 773 regmap_write(dev->regmap, MCHP_I2SMCC_CR, MCHP_I2SMCC_CR_CKDIS); 774 775 if (dev->gclk_running) { 776 clk_disable(dev->gclk); 777 dev->gclk_running = 0; 778 } 779 if (dev->gclk_use) { 780 clk_unprepare(dev->gclk); 781 dev->gclk_use = 0; 782 } 783 } 784 785 return 0; 786} 787 788static int mchp_i2s_mcc_trigger(struct snd_pcm_substream *substream, int cmd, 789 struct snd_soc_dai *dai) 790{ 791 struct mchp_i2s_mcc_dev *dev = snd_soc_dai_get_drvdata(dai); 792 bool is_playback = (substream->stream == SNDRV_PCM_STREAM_PLAYBACK); 793 u32 cr = 0; 794 u32 iera = 0, ierb = 0; 795 u32 sr; 796 int err; 797 798 switch (cmd) { 799 case SNDRV_PCM_TRIGGER_START: 800 case SNDRV_PCM_TRIGGER_RESUME: 801 case SNDRV_PCM_TRIGGER_PAUSE_RELEASE: 802 if (is_playback) 803 cr = MCHP_I2SMCC_CR_TXEN | MCHP_I2SMCC_CR_CKEN; 804 else 805 cr = MCHP_I2SMCC_CR_RXEN | MCHP_I2SMCC_CR_CKEN; 806 break; 807 case SNDRV_PCM_TRIGGER_STOP: 808 case SNDRV_PCM_TRIGGER_SUSPEND: 809 case SNDRV_PCM_TRIGGER_PAUSE_PUSH: 810 regmap_read(dev->regmap, MCHP_I2SMCC_SR, &sr); 811 if (is_playback && (sr & MCHP_I2SMCC_SR_TXEN)) { 812 cr = MCHP_I2SMCC_CR_TXDIS; 813 dev->tx_rdy = 0; 814 /* 815 * Enable Tx Ready interrupts on all channels 816 * to assure all data is sent 817 */ 818 if (dev->soc->has_fifo) 819 ierb = MCHP_I2SMCC_INT_TXFFRDY; 820 else 821 iera = MCHP_I2SMCC_INT_TXRDY_MASK(dev->channels); 822 } else if (!is_playback && (sr & MCHP_I2SMCC_SR_RXEN)) { 823 cr = MCHP_I2SMCC_CR_RXDIS; 824 dev->rx_rdy = 0; 825 /* 826 * Enable Rx Ready interrupts on all channels 827 * to assure all data is received 828 */ 829 if (dev->soc->has_fifo) 830 ierb = MCHP_I2SMCC_INT_RXFFRDY; 831 else 832 iera = MCHP_I2SMCC_INT_RXRDY_MASK(dev->channels); 833 } 834 break; 835 default: 836 return -EINVAL; 837 } 838 839 if ((cr & MCHP_I2SMCC_CR_CKEN) && dev->gclk_use && 840 !dev->gclk_running) { 841 err = clk_enable(dev->gclk); 842 if (err) { 843 dev_err_once(dev->dev, "failed to enable GCLK: %d\n", 844 err); 845 } else { 846 dev->gclk_running = 1; 847 } 848 } 849 850 if (dev->soc->has_fifo) 851 regmap_write(dev->regmap, MCHP_I2SMCC_IERB, ierb); 852 else 853 regmap_write(dev->regmap, MCHP_I2SMCC_IERA, iera); 854 regmap_write(dev->regmap, MCHP_I2SMCC_CR, cr); 855 856 return 0; 857} 858 859static int mchp_i2s_mcc_startup(struct snd_pcm_substream *substream, 860 struct snd_soc_dai *dai) 861{ 862 struct mchp_i2s_mcc_dev *dev = snd_soc_dai_get_drvdata(dai); 863 864 /* Software reset the IP if it's not running */ 865 if (!mchp_i2s_mcc_is_running(dev)) { 866 return regmap_write(dev->regmap, MCHP_I2SMCC_CR, 867 MCHP_I2SMCC_CR_SWRST); 868 } 869 870 return 0; 871} 872 873static const struct snd_soc_dai_ops mchp_i2s_mcc_dai_ops = { 874 .set_sysclk = mchp_i2s_mcc_set_sysclk, 875 .set_bclk_ratio = mchp_i2s_mcc_set_bclk_ratio, 876 .startup = mchp_i2s_mcc_startup, 877 .trigger = mchp_i2s_mcc_trigger, 878 .hw_params = mchp_i2s_mcc_hw_params, 879 .hw_free = mchp_i2s_mcc_hw_free, 880 .set_fmt = mchp_i2s_mcc_set_dai_fmt, 881 .set_tdm_slot = mchp_i2s_mcc_set_dai_tdm_slot, 882}; 883 884static int mchp_i2s_mcc_dai_probe(struct snd_soc_dai *dai) 885{ 886 struct mchp_i2s_mcc_dev *dev = snd_soc_dai_get_drvdata(dai); 887 888 init_waitqueue_head(&dev->wq_txrdy); 889 init_waitqueue_head(&dev->wq_rxrdy); 890 dev->tx_rdy = 1; 891 dev->rx_rdy = 1; 892 893 snd_soc_dai_init_dma_data(dai, &dev->playback, &dev->capture); 894 895 return 0; 896} 897 898#define MCHP_I2SMCC_RATES SNDRV_PCM_RATE_8000_192000 899 900#define MCHP_I2SMCC_FORMATS (SNDRV_PCM_FMTBIT_S8 | \ 901 SNDRV_PCM_FMTBIT_S16_LE | \ 902 SNDRV_PCM_FMTBIT_S18_3LE | \ 903 SNDRV_PCM_FMTBIT_S20_3LE | \ 904 SNDRV_PCM_FMTBIT_S24_3LE | \ 905 SNDRV_PCM_FMTBIT_S24_LE | \ 906 SNDRV_PCM_FMTBIT_S32_LE) 907 908static struct snd_soc_dai_driver mchp_i2s_mcc_dai = { 909 .probe = mchp_i2s_mcc_dai_probe, 910 .playback = { 911 .stream_name = "I2SMCC-Playback", 912 .channels_min = 1, 913 .channels_max = 8, 914 .rates = MCHP_I2SMCC_RATES, 915 .formats = MCHP_I2SMCC_FORMATS, 916 }, 917 .capture = { 918 .stream_name = "I2SMCC-Capture", 919 .channels_min = 1, 920 .channels_max = 8, 921 .rates = MCHP_I2SMCC_RATES, 922 .formats = MCHP_I2SMCC_FORMATS, 923 }, 924 .ops = &mchp_i2s_mcc_dai_ops, 925 .symmetric_rate = 1, 926 .symmetric_sample_bits = 1, 927 .symmetric_channels = 1, 928}; 929 930static const struct snd_soc_component_driver mchp_i2s_mcc_component = { 931 .name = "mchp-i2s-mcc", 932}; 933 934#ifdef CONFIG_OF 935static struct mchp_i2s_mcc_soc_data mchp_i2s_mcc_sam9x60 = { 936 .data_pin_pair_num = 1, 937}; 938 939static struct mchp_i2s_mcc_soc_data mchp_i2s_mcc_sama7g5 = { 940 .data_pin_pair_num = 4, 941 .has_fifo = true, 942}; 943 944static const struct of_device_id mchp_i2s_mcc_dt_ids[] = { 945 { 946 .compatible = "microchip,sam9x60-i2smcc", 947 .data = &mchp_i2s_mcc_sam9x60, 948 }, 949 { 950 .compatible = "microchip,sama7g5-i2smcc", 951 .data = &mchp_i2s_mcc_sama7g5, 952 }, 953 { /* sentinel */ } 954}; 955MODULE_DEVICE_TABLE(of, mchp_i2s_mcc_dt_ids); 956#endif 957 958static int mchp_i2s_mcc_soc_data_parse(struct platform_device *pdev, 959 struct mchp_i2s_mcc_dev *dev) 960{ 961 int err; 962 963 if (!dev->soc) { 964 dev_err(&pdev->dev, "failed to get soc data\n"); 965 return -ENODEV; 966 } 967 968 if (dev->soc->data_pin_pair_num == 1) 969 return 0; 970 971 err = of_property_read_u8(pdev->dev.of_node, "microchip,tdm-data-pair", 972 &dev->tdm_data_pair); 973 if (err < 0 && err != -EINVAL) { 974 dev_err(&pdev->dev, 975 "bad property data for 'microchip,tdm-data-pair': %d", 976 err); 977 return err; 978 } 979 if (err == -EINVAL) { 980 dev_info(&pdev->dev, 981 "'microchip,tdm-data-pair' not found; assuming DIN/DOUT 0 for TDM\n"); 982 dev->tdm_data_pair = 0; 983 } else { 984 if (dev->tdm_data_pair > dev->soc->data_pin_pair_num - 1) { 985 dev_err(&pdev->dev, 986 "invalid value for 'microchip,tdm-data-pair': %d\n", 987 dev->tdm_data_pair); 988 return -EINVAL; 989 } 990 dev_dbg(&pdev->dev, "TMD format on DIN/DOUT %d pins\n", 991 dev->tdm_data_pair); 992 } 993 994 return 0; 995} 996 997static int mchp_i2s_mcc_probe(struct platform_device *pdev) 998{ 999 struct mchp_i2s_mcc_dev *dev; 1000 struct resource *mem; 1001 struct regmap *regmap; 1002 void __iomem *base; 1003 u32 version; 1004 int irq; 1005 int err; 1006 1007 dev = devm_kzalloc(&pdev->dev, sizeof(*dev), GFP_KERNEL); 1008 if (!dev) 1009 return -ENOMEM; 1010 1011 base = devm_platform_get_and_ioremap_resource(pdev, 0, &mem); 1012 if (IS_ERR(base)) 1013 return PTR_ERR(base); 1014 1015 regmap = devm_regmap_init_mmio(&pdev->dev, base, 1016 &mchp_i2s_mcc_regmap_config); 1017 if (IS_ERR(regmap)) 1018 return PTR_ERR(regmap); 1019 1020 irq = platform_get_irq(pdev, 0); 1021 if (irq < 0) 1022 return irq; 1023 1024 err = devm_request_irq(&pdev->dev, irq, mchp_i2s_mcc_interrupt, 0, 1025 dev_name(&pdev->dev), dev); 1026 if (err) 1027 return err; 1028 1029 dev->pclk = devm_clk_get(&pdev->dev, "pclk"); 1030 if (IS_ERR(dev->pclk)) { 1031 err = PTR_ERR(dev->pclk); 1032 dev_err(&pdev->dev, 1033 "failed to get the peripheral clock: %d\n", err); 1034 return err; 1035 } 1036 1037 /* Get the optional generated clock */ 1038 dev->gclk = devm_clk_get(&pdev->dev, "gclk"); 1039 if (IS_ERR(dev->gclk)) { 1040 if (PTR_ERR(dev->gclk) == -EPROBE_DEFER) 1041 return -EPROBE_DEFER; 1042 dev_warn(&pdev->dev, 1043 "generated clock not found: %d\n", err); 1044 dev->gclk = NULL; 1045 } 1046 1047 dev->soc = of_device_get_match_data(&pdev->dev); 1048 err = mchp_i2s_mcc_soc_data_parse(pdev, dev); 1049 if (err < 0) 1050 return err; 1051 1052 dev->dev = &pdev->dev; 1053 dev->regmap = regmap; 1054 platform_set_drvdata(pdev, dev); 1055 1056 err = clk_prepare_enable(dev->pclk); 1057 if (err) { 1058 dev_err(&pdev->dev, 1059 "failed to enable the peripheral clock: %d\n", err); 1060 return err; 1061 } 1062 1063 err = devm_snd_soc_register_component(&pdev->dev, 1064 &mchp_i2s_mcc_component, 1065 &mchp_i2s_mcc_dai, 1); 1066 if (err) { 1067 dev_err(&pdev->dev, "failed to register DAI: %d\n", err); 1068 clk_disable_unprepare(dev->pclk); 1069 return err; 1070 } 1071 1072 dev->playback.addr = (dma_addr_t)mem->start + MCHP_I2SMCC_THR; 1073 dev->capture.addr = (dma_addr_t)mem->start + MCHP_I2SMCC_RHR; 1074 1075 err = devm_snd_dmaengine_pcm_register(&pdev->dev, NULL, 0); 1076 if (err) { 1077 dev_err(&pdev->dev, "failed to register PCM: %d\n", err); 1078 clk_disable_unprepare(dev->pclk); 1079 return err; 1080 } 1081 1082 /* Get IP version. */ 1083 regmap_read(dev->regmap, MCHP_I2SMCC_VERSION, &version); 1084 dev_info(&pdev->dev, "hw version: %#lx\n", 1085 version & MCHP_I2SMCC_VERSION_MASK); 1086 1087 return 0; 1088} 1089 1090static int mchp_i2s_mcc_remove(struct platform_device *pdev) 1091{ 1092 struct mchp_i2s_mcc_dev *dev = platform_get_drvdata(pdev); 1093 1094 clk_disable_unprepare(dev->pclk); 1095 1096 return 0; 1097} 1098 1099static struct platform_driver mchp_i2s_mcc_driver = { 1100 .driver = { 1101 .name = "mchp_i2s_mcc", 1102 .of_match_table = of_match_ptr(mchp_i2s_mcc_dt_ids), 1103 }, 1104 .probe = mchp_i2s_mcc_probe, 1105 .remove = mchp_i2s_mcc_remove, 1106}; 1107module_platform_driver(mchp_i2s_mcc_driver); 1108 1109MODULE_DESCRIPTION("Microchip I2S Multi-Channel Controller driver"); 1110MODULE_AUTHOR("Codrin Ciubotariu <codrin.ciubotariu@microchip.com>"); 1111MODULE_LICENSE("GPL v2");