1 /* 2 * ADF4350/ADF4351 SPI Wideband Synthesizer driver 3 * 4 * Copyright 2012-2013 Analog Devices Inc. 5 * 6 * Licensed under the GPL-2. 7 */ 8 9 #include <linux/device.h> 10 #include <linux/kernel.h> 11 #include <linux/slab.h> 12 #include <linux/sysfs.h> 13 #include <linux/spi/spi.h> 14 #include <linux/regulator/consumer.h> 15 #include <linux/err.h> 16 #include <linux/module.h> 17 #include <linux/gcd.h> 18 #include <linux/gpio.h> 19 #include <asm/div64.h> 20 #include <linux/clk.h> 21 #include <linux/of.h> 22 #include <linux/of_gpio.h> 23 24 #include <linux/iio/iio.h> 25 #include <linux/iio/sysfs.h> 26 #include <linux/iio/frequency/adf4350.h> 27 28 enum { 29 ADF4350_FREQ, 30 ADF4350_FREQ_REFIN, 31 ADF4350_FREQ_RESOLUTION, 32 ADF4350_PWRDOWN, 33 }; 34 35 struct adf4350_state { 36 struct spi_device *spi; 37 struct regulator *reg; 38 struct adf4350_platform_data *pdata; 39 struct clk *clk; 40 unsigned long clkin; 41 unsigned long chspc; /* Channel Spacing */ 42 unsigned long fpfd; /* Phase Frequency Detector */ 43 unsigned long min_out_freq; 44 unsigned r0_fract; 45 unsigned r0_int; 46 unsigned r1_mod; 47 unsigned r4_rf_div_sel; 48 unsigned long regs[6]; 49 unsigned long regs_hw[6]; 50 unsigned long long freq_req; 51 /* 52 * DMA (thus cache coherency maintenance) requires the 53 * transfer buffers to live in their own cache lines. 54 */ 55 __be32 val ____cacheline_aligned; 56 }; 57 58 static struct adf4350_platform_data default_pdata = { 59 .channel_spacing = 10000, 60 .r2_user_settings = ADF4350_REG2_PD_POLARITY_POS | 61 ADF4350_REG2_CHARGE_PUMP_CURR_uA(2500), 62 .r3_user_settings = ADF4350_REG3_12BIT_CLKDIV_MODE(0), 63 .r4_user_settings = ADF4350_REG4_OUTPUT_PWR(3) | 64 ADF4350_REG4_MUTE_TILL_LOCK_EN, 65 .gpio_lock_detect = -1, 66 }; 67 68 static int adf4350_sync_config(struct adf4350_state *st) 69 { 70 int ret, i, doublebuf = 0; 71 72 for (i = ADF4350_REG5; i >= ADF4350_REG0; i--) { 73 if ((st->regs_hw[i] != st->regs[i]) || 74 ((i == ADF4350_REG0) && doublebuf)) { 75 switch (i) { 76 case ADF4350_REG1: 77 case ADF4350_REG4: 78 doublebuf = 1; 79 break; 80 } 81 82 st->val = cpu_to_be32(st->regs[i] | i); 83 ret = spi_write(st->spi, &st->val, 4); 84 if (ret < 0) 85 return ret; 86 st->regs_hw[i] = st->regs[i]; 87 dev_dbg(&st->spi->dev, "[%d] 0x%X\n", 88 i, (u32)st->regs[i] | i); 89 } 90 } 91 return 0; 92 } 93 94 static int adf4350_reg_access(struct iio_dev *indio_dev, 95 unsigned reg, unsigned writeval, 96 unsigned *readval) 97 { 98 struct adf4350_state *st = iio_priv(indio_dev); 99 int ret; 100 101 if (reg > ADF4350_REG5) 102 return -EINVAL; 103 104 mutex_lock(&indio_dev->mlock); 105 if (readval == NULL) { 106 st->regs[reg] = writeval & ~(BIT(0) | BIT(1) | BIT(2)); 107 ret = adf4350_sync_config(st); 108 } else { 109 *readval = st->regs_hw[reg]; 110 ret = 0; 111 } 112 mutex_unlock(&indio_dev->mlock); 113 114 return ret; 115 } 116 117 static int adf4350_tune_r_cnt(struct adf4350_state *st, unsigned short r_cnt) 118 { 119 struct adf4350_platform_data *pdata = st->pdata; 120 121 do { 122 r_cnt++; 123 st->fpfd = (st->clkin * (pdata->ref_doubler_en ? 2 : 1)) / 124 (r_cnt * (pdata->ref_div2_en ? 2 : 1)); 125 } while (st->fpfd > ADF4350_MAX_FREQ_PFD); 126 127 return r_cnt; 128 } 129 130 static int adf4350_set_freq(struct adf4350_state *st, unsigned long long freq) 131 { 132 struct adf4350_platform_data *pdata = st->pdata; 133 u64 tmp; 134 u32 div_gcd, prescaler, chspc; 135 u16 mdiv, r_cnt = 0; 136 u8 band_sel_div; 137 138 if (freq > ADF4350_MAX_OUT_FREQ || freq < st->min_out_freq) 139 return -EINVAL; 140 141 if (freq > ADF4350_MAX_FREQ_45_PRESC) { 142 prescaler = ADF4350_REG1_PRESCALER; 143 mdiv = 75; 144 } else { 145 prescaler = 0; 146 mdiv = 23; 147 } 148 149 st->r4_rf_div_sel = 0; 150 151 while (freq < ADF4350_MIN_VCO_FREQ) { 152 freq <<= 1; 153 st->r4_rf_div_sel++; 154 } 155 156 /* 157 * Allow a predefined reference division factor 158 * if not set, compute our own 159 */ 160 if (pdata->ref_div_factor) 161 r_cnt = pdata->ref_div_factor - 1; 162 163 chspc = st->chspc; 164 165 do { 166 do { 167 do { 168 r_cnt = adf4350_tune_r_cnt(st, r_cnt); 169 st->r1_mod = st->fpfd / chspc; 170 if (r_cnt > ADF4350_MAX_R_CNT) { 171 /* try higher spacing values */ 172 chspc++; 173 r_cnt = 0; 174 } 175 } while ((st->r1_mod > ADF4350_MAX_MODULUS) && r_cnt); 176 } while (r_cnt == 0); 177 178 tmp = freq * (u64)st->r1_mod + (st->fpfd >> 1); 179 do_div(tmp, st->fpfd); /* Div round closest (n + d/2)/d */ 180 st->r0_fract = do_div(tmp, st->r1_mod); 181 st->r0_int = tmp; 182 } while (mdiv > st->r0_int); 183 184 band_sel_div = DIV_ROUND_UP(st->fpfd, ADF4350_MAX_BANDSEL_CLK); 185 186 if (st->r0_fract && st->r1_mod) { 187 div_gcd = gcd(st->r1_mod, st->r0_fract); 188 st->r1_mod /= div_gcd; 189 st->r0_fract /= div_gcd; 190 } else { 191 st->r0_fract = 0; 192 st->r1_mod = 1; 193 } 194 195 dev_dbg(&st->spi->dev, "VCO: %llu Hz, PFD %lu Hz\n" 196 "REF_DIV %d, R0_INT %d, R0_FRACT %d\n" 197 "R1_MOD %d, RF_DIV %d\nPRESCALER %s, BAND_SEL_DIV %d\n", 198 freq, st->fpfd, r_cnt, st->r0_int, st->r0_fract, st->r1_mod, 199 1 << st->r4_rf_div_sel, prescaler ? "8/9" : "4/5", 200 band_sel_div); 201 202 st->regs[ADF4350_REG0] = ADF4350_REG0_INT(st->r0_int) | 203 ADF4350_REG0_FRACT(st->r0_fract); 204 205 st->regs[ADF4350_REG1] = ADF4350_REG1_PHASE(1) | 206 ADF4350_REG1_MOD(st->r1_mod) | 207 prescaler; 208 209 st->regs[ADF4350_REG2] = 210 ADF4350_REG2_10BIT_R_CNT(r_cnt) | 211 ADF4350_REG2_DOUBLE_BUFF_EN | 212 (pdata->ref_doubler_en ? ADF4350_REG2_RMULT2_EN : 0) | 213 (pdata->ref_div2_en ? ADF4350_REG2_RDIV2_EN : 0) | 214 (pdata->r2_user_settings & (ADF4350_REG2_PD_POLARITY_POS | 215 ADF4350_REG2_LDP_6ns | ADF4350_REG2_LDF_INT_N | 216 ADF4350_REG2_CHARGE_PUMP_CURR_uA(5000) | 217 ADF4350_REG2_MUXOUT(0x7) | ADF4350_REG2_NOISE_MODE(0x3))); 218 219 st->regs[ADF4350_REG3] = pdata->r3_user_settings & 220 (ADF4350_REG3_12BIT_CLKDIV(0xFFF) | 221 ADF4350_REG3_12BIT_CLKDIV_MODE(0x3) | 222 ADF4350_REG3_12BIT_CSR_EN | 223 ADF4351_REG3_CHARGE_CANCELLATION_EN | 224 ADF4351_REG3_ANTI_BACKLASH_3ns_EN | 225 ADF4351_REG3_BAND_SEL_CLOCK_MODE_HIGH); 226 227 st->regs[ADF4350_REG4] = 228 ADF4350_REG4_FEEDBACK_FUND | 229 ADF4350_REG4_RF_DIV_SEL(st->r4_rf_div_sel) | 230 ADF4350_REG4_8BIT_BAND_SEL_CLKDIV(band_sel_div) | 231 ADF4350_REG4_RF_OUT_EN | 232 (pdata->r4_user_settings & 233 (ADF4350_REG4_OUTPUT_PWR(0x3) | 234 ADF4350_REG4_AUX_OUTPUT_PWR(0x3) | 235 ADF4350_REG4_AUX_OUTPUT_EN | 236 ADF4350_REG4_AUX_OUTPUT_FUND | 237 ADF4350_REG4_MUTE_TILL_LOCK_EN)); 238 239 st->regs[ADF4350_REG5] = ADF4350_REG5_LD_PIN_MODE_DIGITAL; 240 st->freq_req = freq; 241 242 return adf4350_sync_config(st); 243 } 244 245 static ssize_t adf4350_write(struct iio_dev *indio_dev, 246 uintptr_t private, 247 const struct iio_chan_spec *chan, 248 const char *buf, size_t len) 249 { 250 struct adf4350_state *st = iio_priv(indio_dev); 251 unsigned long long readin; 252 unsigned long tmp; 253 int ret; 254 255 ret = kstrtoull(buf, 10, &readin); 256 if (ret) 257 return ret; 258 259 mutex_lock(&indio_dev->mlock); 260 switch ((u32)private) { 261 case ADF4350_FREQ: 262 ret = adf4350_set_freq(st, readin); 263 break; 264 case ADF4350_FREQ_REFIN: 265 if (readin > ADF4350_MAX_FREQ_REFIN) { 266 ret = -EINVAL; 267 break; 268 } 269 270 if (st->clk) { 271 tmp = clk_round_rate(st->clk, readin); 272 if (tmp != readin) { 273 ret = -EINVAL; 274 break; 275 } 276 ret = clk_set_rate(st->clk, tmp); 277 if (ret < 0) 278 break; 279 } 280 st->clkin = readin; 281 ret = adf4350_set_freq(st, st->freq_req); 282 break; 283 case ADF4350_FREQ_RESOLUTION: 284 if (readin == 0) 285 ret = -EINVAL; 286 else 287 st->chspc = readin; 288 break; 289 case ADF4350_PWRDOWN: 290 if (readin) 291 st->regs[ADF4350_REG2] |= ADF4350_REG2_POWER_DOWN_EN; 292 else 293 st->regs[ADF4350_REG2] &= ~ADF4350_REG2_POWER_DOWN_EN; 294 295 adf4350_sync_config(st); 296 break; 297 default: 298 ret = -EINVAL; 299 } 300 mutex_unlock(&indio_dev->mlock); 301 302 return ret ? ret : len; 303 } 304 305 static ssize_t adf4350_read(struct iio_dev *indio_dev, 306 uintptr_t private, 307 const struct iio_chan_spec *chan, 308 char *buf) 309 { 310 struct adf4350_state *st = iio_priv(indio_dev); 311 unsigned long long val; 312 int ret = 0; 313 314 mutex_lock(&indio_dev->mlock); 315 switch ((u32)private) { 316 case ADF4350_FREQ: 317 val = (u64)((st->r0_int * st->r1_mod) + st->r0_fract) * 318 (u64)st->fpfd; 319 do_div(val, st->r1_mod * (1 << st->r4_rf_div_sel)); 320 /* PLL unlocked? return error */ 321 if (gpio_is_valid(st->pdata->gpio_lock_detect)) 322 if (!gpio_get_value(st->pdata->gpio_lock_detect)) { 323 dev_dbg(&st->spi->dev, "PLL un-locked\n"); 324 ret = -EBUSY; 325 } 326 break; 327 case ADF4350_FREQ_REFIN: 328 if (st->clk) 329 st->clkin = clk_get_rate(st->clk); 330 331 val = st->clkin; 332 break; 333 case ADF4350_FREQ_RESOLUTION: 334 val = st->chspc; 335 break; 336 case ADF4350_PWRDOWN: 337 val = !!(st->regs[ADF4350_REG2] & ADF4350_REG2_POWER_DOWN_EN); 338 break; 339 default: 340 ret = -EINVAL; 341 val = 0; 342 } 343 mutex_unlock(&indio_dev->mlock); 344 345 return ret < 0 ? ret : sprintf(buf, "%llu\n", val); 346 } 347 348 #define _ADF4350_EXT_INFO(_name, _ident) { \ 349 .name = _name, \ 350 .read = adf4350_read, \ 351 .write = adf4350_write, \ 352 .private = _ident, \ 353 .shared = IIO_SEPARATE, \ 354 } 355 356 static const struct iio_chan_spec_ext_info adf4350_ext_info[] = { 357 /* Ideally we use IIO_CHAN_INFO_FREQUENCY, but there are 358 * values > 2^32 in order to support the entire frequency range 359 * in Hz. Using scale is a bit ugly. 360 */ 361 _ADF4350_EXT_INFO("frequency", ADF4350_FREQ), 362 _ADF4350_EXT_INFO("frequency_resolution", ADF4350_FREQ_RESOLUTION), 363 _ADF4350_EXT_INFO("refin_frequency", ADF4350_FREQ_REFIN), 364 _ADF4350_EXT_INFO("powerdown", ADF4350_PWRDOWN), 365 { }, 366 }; 367 368 static const struct iio_chan_spec adf4350_chan = { 369 .type = IIO_ALTVOLTAGE, 370 .indexed = 1, 371 .output = 1, 372 .ext_info = adf4350_ext_info, 373 }; 374 375 static const struct iio_info adf4350_info = { 376 .debugfs_reg_access = &adf4350_reg_access, 377 }; 378 379 #ifdef CONFIG_OF 380 static struct adf4350_platform_data *adf4350_parse_dt(struct device *dev) 381 { 382 struct device_node *np = dev->of_node; 383 struct adf4350_platform_data *pdata; 384 unsigned int tmp; 385 int ret; 386 387 pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL); 388 if (!pdata) 389 return NULL; 390 391 strncpy(&pdata->name[0], np->name, SPI_NAME_SIZE - 1); 392 393 tmp = 10000; 394 of_property_read_u32(np, "adi,channel-spacing", &tmp); 395 pdata->channel_spacing = tmp; 396 397 tmp = 0; 398 of_property_read_u32(np, "adi,power-up-frequency", &tmp); 399 pdata->power_up_frequency = tmp; 400 401 tmp = 0; 402 of_property_read_u32(np, "adi,reference-div-factor", &tmp); 403 pdata->ref_div_factor = tmp; 404 405 ret = of_get_gpio(np, 0); 406 if (ret < 0) 407 pdata->gpio_lock_detect = -1; 408 else 409 pdata->gpio_lock_detect = ret; 410 411 pdata->ref_doubler_en = of_property_read_bool(np, 412 "adi,reference-doubler-enable"); 413 pdata->ref_div2_en = of_property_read_bool(np, 414 "adi,reference-div2-enable"); 415 416 /* r2_user_settings */ 417 pdata->r2_user_settings = of_property_read_bool(np, 418 "adi,phase-detector-polarity-positive-enable") ? 419 ADF4350_REG2_PD_POLARITY_POS : 0; 420 pdata->r2_user_settings |= of_property_read_bool(np, 421 "adi,lock-detect-precision-6ns-enable") ? 422 ADF4350_REG2_LDP_6ns : 0; 423 pdata->r2_user_settings |= of_property_read_bool(np, 424 "adi,lock-detect-function-integer-n-enable") ? 425 ADF4350_REG2_LDF_INT_N : 0; 426 427 tmp = 2500; 428 of_property_read_u32(np, "adi,charge-pump-current", &tmp); 429 pdata->r2_user_settings |= ADF4350_REG2_CHARGE_PUMP_CURR_uA(tmp); 430 431 tmp = 0; 432 of_property_read_u32(np, "adi,muxout-select", &tmp); 433 pdata->r2_user_settings |= ADF4350_REG2_MUXOUT(tmp); 434 435 pdata->r2_user_settings |= of_property_read_bool(np, 436 "adi,low-spur-mode-enable") ? 437 ADF4350_REG2_NOISE_MODE(0x3) : 0; 438 439 /* r3_user_settings */ 440 441 pdata->r3_user_settings = of_property_read_bool(np, 442 "adi,cycle-slip-reduction-enable") ? 443 ADF4350_REG3_12BIT_CSR_EN : 0; 444 pdata->r3_user_settings |= of_property_read_bool(np, 445 "adi,charge-cancellation-enable") ? 446 ADF4351_REG3_CHARGE_CANCELLATION_EN : 0; 447 448 pdata->r3_user_settings |= of_property_read_bool(np, 449 "adi,anti-backlash-3ns-enable") ? 450 ADF4351_REG3_ANTI_BACKLASH_3ns_EN : 0; 451 pdata->r3_user_settings |= of_property_read_bool(np, 452 "adi,band-select-clock-mode-high-enable") ? 453 ADF4351_REG3_BAND_SEL_CLOCK_MODE_HIGH : 0; 454 455 tmp = 0; 456 of_property_read_u32(np, "adi,12bit-clk-divider", &tmp); 457 pdata->r3_user_settings |= ADF4350_REG3_12BIT_CLKDIV(tmp); 458 459 tmp = 0; 460 of_property_read_u32(np, "adi,clk-divider-mode", &tmp); 461 pdata->r3_user_settings |= ADF4350_REG3_12BIT_CLKDIV_MODE(tmp); 462 463 /* r4_user_settings */ 464 465 pdata->r4_user_settings = of_property_read_bool(np, 466 "adi,aux-output-enable") ? 467 ADF4350_REG4_AUX_OUTPUT_EN : 0; 468 pdata->r4_user_settings |= of_property_read_bool(np, 469 "adi,aux-output-fundamental-enable") ? 470 ADF4350_REG4_AUX_OUTPUT_FUND : 0; 471 pdata->r4_user_settings |= of_property_read_bool(np, 472 "adi,mute-till-lock-enable") ? 473 ADF4350_REG4_MUTE_TILL_LOCK_EN : 0; 474 475 tmp = 0; 476 of_property_read_u32(np, "adi,output-power", &tmp); 477 pdata->r4_user_settings |= ADF4350_REG4_OUTPUT_PWR(tmp); 478 479 tmp = 0; 480 of_property_read_u32(np, "adi,aux-output-power", &tmp); 481 pdata->r4_user_settings |= ADF4350_REG4_AUX_OUTPUT_PWR(tmp); 482 483 return pdata; 484 } 485 #else 486 static 487 struct adf4350_platform_data *adf4350_parse_dt(struct device *dev) 488 { 489 return NULL; 490 } 491 #endif 492 493 static int adf4350_probe(struct spi_device *spi) 494 { 495 struct adf4350_platform_data *pdata; 496 struct iio_dev *indio_dev; 497 struct adf4350_state *st; 498 struct clk *clk = NULL; 499 int ret; 500 501 if (spi->dev.of_node) { 502 pdata = adf4350_parse_dt(&spi->dev); 503 if (pdata == NULL) 504 return -EINVAL; 505 } else { 506 pdata = spi->dev.platform_data; 507 } 508 509 if (!pdata) { 510 dev_warn(&spi->dev, "no platform data? using default\n"); 511 pdata = &default_pdata; 512 } 513 514 if (!pdata->clkin) { 515 clk = devm_clk_get(&spi->dev, "clkin"); 516 if (IS_ERR(clk)) 517 return -EPROBE_DEFER; 518 519 ret = clk_prepare_enable(clk); 520 if (ret < 0) 521 return ret; 522 } 523 524 indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st)); 525 if (indio_dev == NULL) { 526 ret = -ENOMEM; 527 goto error_disable_clk; 528 } 529 530 st = iio_priv(indio_dev); 531 532 st->reg = devm_regulator_get(&spi->dev, "vcc"); 533 if (!IS_ERR(st->reg)) { 534 ret = regulator_enable(st->reg); 535 if (ret) 536 goto error_disable_clk; 537 } 538 539 spi_set_drvdata(spi, indio_dev); 540 st->spi = spi; 541 st->pdata = pdata; 542 543 indio_dev->dev.parent = &spi->dev; 544 indio_dev->name = (pdata->name[0] != 0) ? pdata->name : 545 spi_get_device_id(spi)->name; 546 547 indio_dev->info = &adf4350_info; 548 indio_dev->modes = INDIO_DIRECT_MODE; 549 indio_dev->channels = &adf4350_chan; 550 indio_dev->num_channels = 1; 551 552 st->chspc = pdata->channel_spacing; 553 if (clk) { 554 st->clk = clk; 555 st->clkin = clk_get_rate(clk); 556 } else { 557 st->clkin = pdata->clkin; 558 } 559 560 st->min_out_freq = spi_get_device_id(spi)->driver_data == 4351 ? 561 ADF4351_MIN_OUT_FREQ : ADF4350_MIN_OUT_FREQ; 562 563 memset(st->regs_hw, 0xFF, sizeof(st->regs_hw)); 564 565 if (gpio_is_valid(pdata->gpio_lock_detect)) { 566 ret = devm_gpio_request(&spi->dev, pdata->gpio_lock_detect, 567 indio_dev->name); 568 if (ret) { 569 dev_err(&spi->dev, "fail to request lock detect GPIO-%d", 570 pdata->gpio_lock_detect); 571 goto error_disable_reg; 572 } 573 gpio_direction_input(pdata->gpio_lock_detect); 574 } 575 576 if (pdata->power_up_frequency) { 577 ret = adf4350_set_freq(st, pdata->power_up_frequency); 578 if (ret) 579 goto error_disable_reg; 580 } 581 582 ret = iio_device_register(indio_dev); 583 if (ret) 584 goto error_disable_reg; 585 586 return 0; 587 588 error_disable_reg: 589 if (!IS_ERR(st->reg)) 590 regulator_disable(st->reg); 591 error_disable_clk: 592 if (clk) 593 clk_disable_unprepare(clk); 594 595 return ret; 596 } 597 598 static int adf4350_remove(struct spi_device *spi) 599 { 600 struct iio_dev *indio_dev = spi_get_drvdata(spi); 601 struct adf4350_state *st = iio_priv(indio_dev); 602 struct regulator *reg = st->reg; 603 604 st->regs[ADF4350_REG2] |= ADF4350_REG2_POWER_DOWN_EN; 605 adf4350_sync_config(st); 606 607 iio_device_unregister(indio_dev); 608 609 if (st->clk) 610 clk_disable_unprepare(st->clk); 611 612 if (!IS_ERR(reg)) 613 regulator_disable(reg); 614 615 return 0; 616 } 617 618 static const struct of_device_id adf4350_of_match[] = { 619 { .compatible = "adi,adf4350", }, 620 { .compatible = "adi,adf4351", }, 621 { /* sentinel */ }, 622 }; 623 MODULE_DEVICE_TABLE(of, adf4350_of_match); 624 625 static const struct spi_device_id adf4350_id[] = { 626 {"adf4350", 4350}, 627 {"adf4351", 4351}, 628 {} 629 }; 630 MODULE_DEVICE_TABLE(spi, adf4350_id); 631 632 static struct spi_driver adf4350_driver = { 633 .driver = { 634 .name = "adf4350", 635 .of_match_table = of_match_ptr(adf4350_of_match), 636 }, 637 .probe = adf4350_probe, 638 .remove = adf4350_remove, 639 .id_table = adf4350_id, 640 }; 641 module_spi_driver(adf4350_driver); 642 643 MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>"); 644 MODULE_DESCRIPTION("Analog Devices ADF4350/ADF4351 PLL"); 645 MODULE_LICENSE("GPL v2"); 646