1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * ADMV1013 driver 4 * 5 * Copyright 2021 Analog Devices Inc. 6 */ 7 8 #include <linux/bitfield.h> 9 #include <linux/bits.h> 10 #include <linux/clk.h> 11 #include <linux/device.h> 12 #include <linux/iio/iio.h> 13 #include <linux/module.h> 14 #include <linux/mod_devicetable.h> 15 #include <linux/notifier.h> 16 #include <linux/property.h> 17 #include <linux/regulator/consumer.h> 18 #include <linux/spi/spi.h> 19 #include <linux/units.h> 20 21 #include <asm/unaligned.h> 22 23 /* ADMV1013 Register Map */ 24 #define ADMV1013_REG_SPI_CONTROL 0x00 25 #define ADMV1013_REG_ALARM 0x01 26 #define ADMV1013_REG_ALARM_MASKS 0x02 27 #define ADMV1013_REG_ENABLE 0x03 28 #define ADMV1013_REG_LO_AMP_I 0x05 29 #define ADMV1013_REG_LO_AMP_Q 0x06 30 #define ADMV1013_REG_OFFSET_ADJUST_I 0x07 31 #define ADMV1013_REG_OFFSET_ADJUST_Q 0x08 32 #define ADMV1013_REG_QUAD 0x09 33 #define ADMV1013_REG_VVA_TEMP_COMP 0x0A 34 35 /* ADMV1013_REG_SPI_CONTROL Map */ 36 #define ADMV1013_PARITY_EN_MSK BIT(15) 37 #define ADMV1013_SPI_SOFT_RESET_MSK BIT(14) 38 #define ADMV1013_CHIP_ID_MSK GENMASK(11, 4) 39 #define ADMV1013_CHIP_ID 0xA 40 #define ADMV1013_REVISION_ID_MSK GENMASK(3, 0) 41 42 /* ADMV1013_REG_ALARM Map */ 43 #define ADMV1013_PARITY_ERROR_MSK BIT(15) 44 #define ADMV1013_TOO_FEW_ERRORS_MSK BIT(14) 45 #define ADMV1013_TOO_MANY_ERRORS_MSK BIT(13) 46 #define ADMV1013_ADDRESS_RANGE_ERROR_MSK BIT(12) 47 48 /* ADMV1013_REG_ENABLE Map */ 49 #define ADMV1013_VGA_PD_MSK BIT(15) 50 #define ADMV1013_MIXER_PD_MSK BIT(14) 51 #define ADMV1013_QUAD_PD_MSK GENMASK(13, 11) 52 #define ADMV1013_BG_PD_MSK BIT(10) 53 #define ADMV1013_MIXER_IF_EN_MSK BIT(7) 54 #define ADMV1013_DET_EN_MSK BIT(5) 55 56 /* ADMV1013_REG_LO_AMP Map */ 57 #define ADMV1013_LOAMP_PH_ADJ_FINE_MSK GENMASK(13, 7) 58 #define ADMV1013_MIXER_VGATE_MSK GENMASK(6, 0) 59 60 /* ADMV1013_REG_OFFSET_ADJUST Map */ 61 #define ADMV1013_MIXER_OFF_ADJ_P_MSK GENMASK(15, 9) 62 #define ADMV1013_MIXER_OFF_ADJ_N_MSK GENMASK(8, 2) 63 64 /* ADMV1013_REG_QUAD Map */ 65 #define ADMV1013_QUAD_SE_MODE_MSK GENMASK(9, 6) 66 #define ADMV1013_QUAD_FILTERS_MSK GENMASK(3, 0) 67 68 /* ADMV1013_REG_VVA_TEMP_COMP Map */ 69 #define ADMV1013_VVA_TEMP_COMP_MSK GENMASK(15, 0) 70 71 /* ADMV1013 Miscellaneous Defines */ 72 #define ADMV1013_READ BIT(7) 73 #define ADMV1013_REG_ADDR_READ_MSK GENMASK(6, 1) 74 #define ADMV1013_REG_ADDR_WRITE_MSK GENMASK(22, 17) 75 #define ADMV1013_REG_DATA_MSK GENMASK(16, 1) 76 77 enum { 78 ADMV1013_IQ_MODE, 79 ADMV1013_IF_MODE 80 }; 81 82 enum { 83 ADMV1013_RFMOD_I_CALIBPHASE, 84 ADMV1013_RFMOD_Q_CALIBPHASE, 85 }; 86 87 enum { 88 ADMV1013_SE_MODE_POS = 6, 89 ADMV1013_SE_MODE_NEG = 9, 90 ADMV1013_SE_MODE_DIFF = 12 91 }; 92 93 struct admv1013_state { 94 struct spi_device *spi; 95 struct clk *clkin; 96 /* Protect against concurrent accesses to the device and to data */ 97 struct mutex lock; 98 struct regulator *reg; 99 struct notifier_block nb; 100 unsigned int input_mode; 101 unsigned int quad_se_mode; 102 bool det_en; 103 u8 data[3] ____cacheline_aligned; 104 }; 105 106 static int __admv1013_spi_read(struct admv1013_state *st, unsigned int reg, 107 unsigned int *val) 108 { 109 int ret; 110 struct spi_transfer t = {0}; 111 112 st->data[0] = ADMV1013_READ | FIELD_PREP(ADMV1013_REG_ADDR_READ_MSK, reg); 113 st->data[1] = 0x0; 114 st->data[2] = 0x0; 115 116 t.rx_buf = &st->data[0]; 117 t.tx_buf = &st->data[0]; 118 t.len = 3; 119 120 ret = spi_sync_transfer(st->spi, &t, 1); 121 if (ret) 122 return ret; 123 124 *val = FIELD_GET(ADMV1013_REG_DATA_MSK, get_unaligned_be24(&st->data[0])); 125 126 return ret; 127 } 128 129 static int admv1013_spi_read(struct admv1013_state *st, unsigned int reg, 130 unsigned int *val) 131 { 132 int ret; 133 134 mutex_lock(&st->lock); 135 ret = __admv1013_spi_read(st, reg, val); 136 mutex_unlock(&st->lock); 137 138 return ret; 139 } 140 141 static int __admv1013_spi_write(struct admv1013_state *st, 142 unsigned int reg, 143 unsigned int val) 144 { 145 put_unaligned_be24(FIELD_PREP(ADMV1013_REG_DATA_MSK, val) | 146 FIELD_PREP(ADMV1013_REG_ADDR_WRITE_MSK, reg), &st->data[0]); 147 148 return spi_write(st->spi, &st->data[0], 3); 149 } 150 151 static int admv1013_spi_write(struct admv1013_state *st, unsigned int reg, 152 unsigned int val) 153 { 154 int ret; 155 156 mutex_lock(&st->lock); 157 ret = __admv1013_spi_write(st, reg, val); 158 mutex_unlock(&st->lock); 159 160 return ret; 161 } 162 163 static int __admv1013_spi_update_bits(struct admv1013_state *st, unsigned int reg, 164 unsigned int mask, unsigned int val) 165 { 166 int ret; 167 unsigned int data, temp; 168 169 ret = __admv1013_spi_read(st, reg, &data); 170 if (ret) 171 return ret; 172 173 temp = (data & ~mask) | (val & mask); 174 175 return __admv1013_spi_write(st, reg, temp); 176 } 177 178 static int admv1013_spi_update_bits(struct admv1013_state *st, unsigned int reg, 179 unsigned int mask, unsigned int val) 180 { 181 int ret; 182 183 mutex_lock(&st->lock); 184 ret = __admv1013_spi_update_bits(st, reg, mask, val); 185 mutex_unlock(&st->lock); 186 187 return ret; 188 } 189 190 static int admv1013_read_raw(struct iio_dev *indio_dev, 191 struct iio_chan_spec const *chan, 192 int *val, int *val2, long info) 193 { 194 struct admv1013_state *st = iio_priv(indio_dev); 195 unsigned int data, addr; 196 int ret; 197 198 switch (info) { 199 case IIO_CHAN_INFO_CALIBBIAS: 200 switch (chan->channel) { 201 case IIO_MOD_I: 202 addr = ADMV1013_REG_OFFSET_ADJUST_I; 203 break; 204 case IIO_MOD_Q: 205 addr = ADMV1013_REG_OFFSET_ADJUST_Q; 206 break; 207 default: 208 return -EINVAL; 209 } 210 211 ret = admv1013_spi_read(st, addr, &data); 212 if (ret) 213 return ret; 214 215 if (!chan->channel) 216 *val = FIELD_GET(ADMV1013_MIXER_OFF_ADJ_P_MSK, data); 217 else 218 *val = FIELD_GET(ADMV1013_MIXER_OFF_ADJ_N_MSK, data); 219 220 return IIO_VAL_INT; 221 default: 222 return -EINVAL; 223 } 224 } 225 226 static int admv1013_write_raw(struct iio_dev *indio_dev, 227 struct iio_chan_spec const *chan, 228 int val, int val2, long info) 229 { 230 struct admv1013_state *st = iio_priv(indio_dev); 231 unsigned int addr, data, msk; 232 233 switch (info) { 234 case IIO_CHAN_INFO_CALIBBIAS: 235 switch (chan->channel2) { 236 case IIO_MOD_I: 237 addr = ADMV1013_REG_OFFSET_ADJUST_I; 238 break; 239 case IIO_MOD_Q: 240 addr = ADMV1013_REG_OFFSET_ADJUST_Q; 241 break; 242 default: 243 return -EINVAL; 244 } 245 246 if (!chan->channel) { 247 msk = ADMV1013_MIXER_OFF_ADJ_P_MSK; 248 data = FIELD_PREP(ADMV1013_MIXER_OFF_ADJ_P_MSK, val); 249 } else { 250 msk = ADMV1013_MIXER_OFF_ADJ_N_MSK; 251 data = FIELD_PREP(ADMV1013_MIXER_OFF_ADJ_N_MSK, val); 252 } 253 254 return admv1013_spi_update_bits(st, addr, msk, data); 255 default: 256 return -EINVAL; 257 } 258 } 259 260 static ssize_t admv1013_read(struct iio_dev *indio_dev, 261 uintptr_t private, 262 const struct iio_chan_spec *chan, 263 char *buf) 264 { 265 struct admv1013_state *st = iio_priv(indio_dev); 266 unsigned int data, addr; 267 int ret; 268 269 switch ((u32)private) { 270 case ADMV1013_RFMOD_I_CALIBPHASE: 271 addr = ADMV1013_REG_LO_AMP_I; 272 break; 273 case ADMV1013_RFMOD_Q_CALIBPHASE: 274 addr = ADMV1013_REG_LO_AMP_Q; 275 break; 276 default: 277 return -EINVAL; 278 } 279 280 ret = admv1013_spi_read(st, addr, &data); 281 if (ret) 282 return ret; 283 284 data = FIELD_GET(ADMV1013_LOAMP_PH_ADJ_FINE_MSK, data); 285 286 return sysfs_emit(buf, "%u\n", data); 287 } 288 289 static ssize_t admv1013_write(struct iio_dev *indio_dev, 290 uintptr_t private, 291 const struct iio_chan_spec *chan, 292 const char *buf, size_t len) 293 { 294 struct admv1013_state *st = iio_priv(indio_dev); 295 unsigned int data; 296 int ret; 297 298 ret = kstrtou32(buf, 10, &data); 299 if (ret) 300 return ret; 301 302 data = FIELD_PREP(ADMV1013_LOAMP_PH_ADJ_FINE_MSK, data); 303 304 switch ((u32)private) { 305 case ADMV1013_RFMOD_I_CALIBPHASE: 306 ret = admv1013_spi_update_bits(st, ADMV1013_REG_LO_AMP_I, 307 ADMV1013_LOAMP_PH_ADJ_FINE_MSK, 308 data); 309 if (ret) 310 return ret; 311 break; 312 case ADMV1013_RFMOD_Q_CALIBPHASE: 313 ret = admv1013_spi_update_bits(st, ADMV1013_REG_LO_AMP_Q, 314 ADMV1013_LOAMP_PH_ADJ_FINE_MSK, 315 data); 316 if (ret) 317 return ret; 318 break; 319 default: 320 return -EINVAL; 321 } 322 323 return ret ? ret : len; 324 } 325 326 static int admv1013_update_quad_filters(struct admv1013_state *st) 327 { 328 unsigned int filt_raw; 329 u64 rate = clk_get_rate(st->clkin); 330 331 if (rate >= (5400 * HZ_PER_MHZ) && rate <= (7000 * HZ_PER_MHZ)) 332 filt_raw = 15; 333 else if (rate >= (5400 * HZ_PER_MHZ) && rate <= (8000 * HZ_PER_MHZ)) 334 filt_raw = 10; 335 else if (rate >= (6600 * HZ_PER_MHZ) && rate <= (9200 * HZ_PER_MHZ)) 336 filt_raw = 5; 337 else 338 filt_raw = 0; 339 340 return __admv1013_spi_update_bits(st, ADMV1013_REG_QUAD, 341 ADMV1013_QUAD_FILTERS_MSK, 342 FIELD_PREP(ADMV1013_QUAD_FILTERS_MSK, filt_raw)); 343 } 344 345 static int admv1013_update_mixer_vgate(struct admv1013_state *st) 346 { 347 unsigned int vcm, mixer_vgate; 348 349 vcm = regulator_get_voltage(st->reg); 350 351 if (vcm < 1800000) 352 mixer_vgate = (2389 * vcm / 1000000 + 8100) / 100; 353 else if (vcm > 1800000 && vcm < 2600000) 354 mixer_vgate = (2375 * vcm / 1000000 + 125) / 100; 355 else 356 return -EINVAL; 357 358 return __admv1013_spi_update_bits(st, ADMV1013_REG_LO_AMP_I, 359 ADMV1013_MIXER_VGATE_MSK, 360 FIELD_PREP(ADMV1013_MIXER_VGATE_MSK, mixer_vgate)); 361 } 362 363 static int admv1013_reg_access(struct iio_dev *indio_dev, 364 unsigned int reg, 365 unsigned int write_val, 366 unsigned int *read_val) 367 { 368 struct admv1013_state *st = iio_priv(indio_dev); 369 370 if (read_val) 371 return admv1013_spi_read(st, reg, read_val); 372 else 373 return admv1013_spi_write(st, reg, write_val); 374 } 375 376 static const struct iio_info admv1013_info = { 377 .read_raw = admv1013_read_raw, 378 .write_raw = admv1013_write_raw, 379 .debugfs_reg_access = &admv1013_reg_access, 380 }; 381 382 static int admv1013_freq_change(struct notifier_block *nb, unsigned long action, void *data) 383 { 384 struct admv1013_state *st = container_of(nb, struct admv1013_state, nb); 385 int ret; 386 387 if (action == POST_RATE_CHANGE) { 388 mutex_lock(&st->lock); 389 ret = notifier_from_errno(admv1013_update_quad_filters(st)); 390 mutex_unlock(&st->lock); 391 return ret; 392 } 393 394 return NOTIFY_OK; 395 } 396 397 #define _ADMV1013_EXT_INFO(_name, _shared, _ident) { \ 398 .name = _name, \ 399 .read = admv1013_read, \ 400 .write = admv1013_write, \ 401 .private = _ident, \ 402 .shared = _shared, \ 403 } 404 405 static const struct iio_chan_spec_ext_info admv1013_ext_info[] = { 406 _ADMV1013_EXT_INFO("i_calibphase", IIO_SEPARATE, ADMV1013_RFMOD_I_CALIBPHASE), 407 _ADMV1013_EXT_INFO("q_calibphase", IIO_SEPARATE, ADMV1013_RFMOD_Q_CALIBPHASE), 408 { }, 409 }; 410 411 #define ADMV1013_CHAN_PHASE(_channel, _channel2, _admv1013_ext_info) { \ 412 .type = IIO_ALTVOLTAGE, \ 413 .output = 0, \ 414 .indexed = 1, \ 415 .channel2 = _channel2, \ 416 .channel = _channel, \ 417 .differential = 1, \ 418 .ext_info = _admv1013_ext_info, \ 419 } 420 421 #define ADMV1013_CHAN_CALIB(_channel, rf_comp) { \ 422 .type = IIO_ALTVOLTAGE, \ 423 .output = 0, \ 424 .indexed = 1, \ 425 .channel = _channel, \ 426 .channel2 = IIO_MOD_##rf_comp, \ 427 .info_mask_separate = BIT(IIO_CHAN_INFO_CALIBBIAS), \ 428 } 429 430 static const struct iio_chan_spec admv1013_channels[] = { 431 ADMV1013_CHAN_PHASE(0, 1, admv1013_ext_info), 432 ADMV1013_CHAN_CALIB(0, I), 433 ADMV1013_CHAN_CALIB(0, Q), 434 ADMV1013_CHAN_CALIB(1, I), 435 ADMV1013_CHAN_CALIB(1, Q), 436 }; 437 438 static int admv1013_init(struct admv1013_state *st) 439 { 440 int ret; 441 unsigned int data; 442 struct spi_device *spi = st->spi; 443 444 /* Perform a software reset */ 445 ret = __admv1013_spi_update_bits(st, ADMV1013_REG_SPI_CONTROL, 446 ADMV1013_SPI_SOFT_RESET_MSK, 447 FIELD_PREP(ADMV1013_SPI_SOFT_RESET_MSK, 1)); 448 if (ret) 449 return ret; 450 451 ret = __admv1013_spi_update_bits(st, ADMV1013_REG_SPI_CONTROL, 452 ADMV1013_SPI_SOFT_RESET_MSK, 453 FIELD_PREP(ADMV1013_SPI_SOFT_RESET_MSK, 0)); 454 if (ret) 455 return ret; 456 457 ret = __admv1013_spi_read(st, ADMV1013_REG_SPI_CONTROL, &data); 458 if (ret) 459 return ret; 460 461 data = FIELD_GET(ADMV1013_CHIP_ID_MSK, data); 462 if (data != ADMV1013_CHIP_ID) { 463 dev_err(&spi->dev, "Invalid Chip ID.\n"); 464 return -EINVAL; 465 } 466 467 ret = __admv1013_spi_write(st, ADMV1013_REG_VVA_TEMP_COMP, 0xE700); 468 if (ret) 469 return ret; 470 471 data = FIELD_PREP(ADMV1013_QUAD_SE_MODE_MSK, st->quad_se_mode); 472 473 ret = __admv1013_spi_update_bits(st, ADMV1013_REG_QUAD, 474 ADMV1013_QUAD_SE_MODE_MSK, data); 475 if (ret) 476 return ret; 477 478 ret = admv1013_update_mixer_vgate(st); 479 if (ret) 480 return ret; 481 482 ret = admv1013_update_quad_filters(st); 483 if (ret) 484 return ret; 485 486 return __admv1013_spi_update_bits(st, ADMV1013_REG_ENABLE, 487 ADMV1013_DET_EN_MSK | 488 ADMV1013_MIXER_IF_EN_MSK, 489 st->det_en | 490 st->input_mode); 491 } 492 493 static void admv1013_clk_disable(void *data) 494 { 495 clk_disable_unprepare(data); 496 } 497 498 static void admv1013_reg_disable(void *data) 499 { 500 regulator_disable(data); 501 } 502 503 static void admv1013_powerdown(void *data) 504 { 505 unsigned int enable_reg, enable_reg_msk; 506 507 /* Disable all components in the Enable Register */ 508 enable_reg_msk = ADMV1013_VGA_PD_MSK | 509 ADMV1013_MIXER_PD_MSK | 510 ADMV1013_QUAD_PD_MSK | 511 ADMV1013_BG_PD_MSK | 512 ADMV1013_MIXER_IF_EN_MSK | 513 ADMV1013_DET_EN_MSK; 514 515 enable_reg = FIELD_PREP(ADMV1013_VGA_PD_MSK, 1) | 516 FIELD_PREP(ADMV1013_MIXER_PD_MSK, 1) | 517 FIELD_PREP(ADMV1013_QUAD_PD_MSK, 7) | 518 FIELD_PREP(ADMV1013_BG_PD_MSK, 1) | 519 FIELD_PREP(ADMV1013_MIXER_IF_EN_MSK, 0) | 520 FIELD_PREP(ADMV1013_DET_EN_MSK, 0); 521 522 admv1013_spi_update_bits(data, ADMV1013_REG_ENABLE, enable_reg_msk, enable_reg); 523 } 524 525 static int admv1013_properties_parse(struct admv1013_state *st) 526 { 527 int ret; 528 const char *str; 529 struct spi_device *spi = st->spi; 530 531 st->det_en = device_property_read_bool(&spi->dev, "adi,detector-enable"); 532 533 ret = device_property_read_string(&spi->dev, "adi,input-mode", &str); 534 if (ret) 535 st->input_mode = ADMV1013_IQ_MODE; 536 537 if (!strcmp(str, "iq")) 538 st->input_mode = ADMV1013_IQ_MODE; 539 else if (!strcmp(str, "if")) 540 st->input_mode = ADMV1013_IF_MODE; 541 else 542 return -EINVAL; 543 544 ret = device_property_read_string(&spi->dev, "adi,quad-se-mode", &str); 545 if (ret) 546 st->quad_se_mode = ADMV1013_SE_MODE_DIFF; 547 548 if (!strcmp(str, "diff")) 549 st->quad_se_mode = ADMV1013_SE_MODE_DIFF; 550 else if (!strcmp(str, "se-pos")) 551 st->quad_se_mode = ADMV1013_SE_MODE_POS; 552 else if (!strcmp(str, "se-neg")) 553 st->quad_se_mode = ADMV1013_SE_MODE_NEG; 554 else 555 return -EINVAL; 556 557 st->reg = devm_regulator_get(&spi->dev, "vcm"); 558 if (IS_ERR(st->reg)) 559 return dev_err_probe(&spi->dev, PTR_ERR(st->reg), 560 "failed to get the common-mode voltage\n"); 561 562 st->clkin = devm_clk_get(&spi->dev, "lo_in"); 563 if (IS_ERR(st->clkin)) 564 return dev_err_probe(&spi->dev, PTR_ERR(st->clkin), 565 "failed to get the LO input clock\n"); 566 567 return 0; 568 } 569 570 static int admv1013_probe(struct spi_device *spi) 571 { 572 struct iio_dev *indio_dev; 573 struct admv1013_state *st; 574 int ret; 575 576 indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st)); 577 if (!indio_dev) 578 return -ENOMEM; 579 580 st = iio_priv(indio_dev); 581 582 indio_dev->info = &admv1013_info; 583 indio_dev->name = "admv1013"; 584 indio_dev->channels = admv1013_channels; 585 indio_dev->num_channels = ARRAY_SIZE(admv1013_channels); 586 587 st->spi = spi; 588 589 ret = admv1013_properties_parse(st); 590 if (ret) 591 return ret; 592 593 ret = regulator_enable(st->reg); 594 if (ret) { 595 dev_err(&spi->dev, "Failed to enable specified Common-Mode Voltage!\n"); 596 return ret; 597 } 598 599 ret = devm_add_action_or_reset(&spi->dev, admv1013_reg_disable, 600 st->reg); 601 if (ret) 602 return ret; 603 604 ret = clk_prepare_enable(st->clkin); 605 if (ret) 606 return ret; 607 608 ret = devm_add_action_or_reset(&spi->dev, admv1013_clk_disable, st->clkin); 609 if (ret) 610 return ret; 611 612 st->nb.notifier_call = admv1013_freq_change; 613 ret = devm_clk_notifier_register(&spi->dev, st->clkin, &st->nb); 614 if (ret) 615 return ret; 616 617 mutex_init(&st->lock); 618 619 ret = admv1013_init(st); 620 if (ret) { 621 dev_err(&spi->dev, "admv1013 init failed\n"); 622 return ret; 623 } 624 625 ret = devm_add_action_or_reset(&spi->dev, admv1013_powerdown, st); 626 if (ret) 627 return ret; 628 629 return devm_iio_device_register(&spi->dev, indio_dev); 630 } 631 632 static const struct spi_device_id admv1013_id[] = { 633 { "admv1013", 0 }, 634 {} 635 }; 636 MODULE_DEVICE_TABLE(spi, admv1013_id); 637 638 static const struct of_device_id admv1013_of_match[] = { 639 { .compatible = "adi,admv1013" }, 640 {}, 641 }; 642 MODULE_DEVICE_TABLE(of, admv1013_of_match); 643 644 static struct spi_driver admv1013_driver = { 645 .driver = { 646 .name = "admv1013", 647 .of_match_table = admv1013_of_match, 648 }, 649 .probe = admv1013_probe, 650 .id_table = admv1013_id, 651 }; 652 module_spi_driver(admv1013_driver); 653 654 MODULE_AUTHOR("Antoniu Miclaus <antoniu.miclaus@analog.com"); 655 MODULE_DESCRIPTION("Analog Devices ADMV1013"); 656 MODULE_LICENSE("GPL v2"); 657