1 /* 2 * Renesas R-Car GyroADC driver 3 * 4 * Copyright 2016 Marek Vasut <marek.vasut@gmail.com> 5 * 6 * This program is free software; you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License as published by 8 * the Free Software Foundation; either version 2 of the License, or 9 * (at your option) any later version. 10 * 11 * This program is distributed in the hope that it will be useful, 12 * but WITHOUT ANY WARRANTY; without even the implied warranty of 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14 * GNU General Public License for more details. 15 */ 16 17 #include <linux/module.h> 18 #include <linux/platform_device.h> 19 #include <linux/delay.h> 20 #include <linux/kernel.h> 21 #include <linux/slab.h> 22 #include <linux/io.h> 23 #include <linux/clk.h> 24 #include <linux/of.h> 25 #include <linux/of_irq.h> 26 #include <linux/regulator/consumer.h> 27 #include <linux/of_platform.h> 28 #include <linux/err.h> 29 #include <linux/pm_runtime.h> 30 31 #include <linux/iio/iio.h> 32 #include <linux/iio/sysfs.h> 33 #include <linux/iio/trigger.h> 34 35 #define DRIVER_NAME "rcar-gyroadc" 36 37 /* GyroADC registers. */ 38 #define RCAR_GYROADC_MODE_SELECT 0x00 39 #define RCAR_GYROADC_MODE_SELECT_1_MB88101A 0x0 40 #define RCAR_GYROADC_MODE_SELECT_2_ADCS7476 0x1 41 #define RCAR_GYROADC_MODE_SELECT_3_MAX1162 0x3 42 43 #define RCAR_GYROADC_START_STOP 0x04 44 #define RCAR_GYROADC_START_STOP_START BIT(0) 45 46 #define RCAR_GYROADC_CLOCK_LENGTH 0x08 47 #define RCAR_GYROADC_1_25MS_LENGTH 0x0c 48 49 #define RCAR_GYROADC_REALTIME_DATA(ch) (0x10 + ((ch) * 4)) 50 #define RCAR_GYROADC_100MS_ADDED_DATA(ch) (0x30 + ((ch) * 4)) 51 #define RCAR_GYROADC_10MS_AVG_DATA(ch) (0x50 + ((ch) * 4)) 52 53 #define RCAR_GYROADC_FIFO_STATUS 0x70 54 #define RCAR_GYROADC_FIFO_STATUS_EMPTY(ch) BIT(0 + (4 * (ch))) 55 #define RCAR_GYROADC_FIFO_STATUS_FULL(ch) BIT(1 + (4 * (ch))) 56 #define RCAR_GYROADC_FIFO_STATUS_ERROR(ch) BIT(2 + (4 * (ch))) 57 58 #define RCAR_GYROADC_INTR 0x74 59 #define RCAR_GYROADC_INTR_INT BIT(0) 60 61 #define RCAR_GYROADC_INTENR 0x78 62 #define RCAR_GYROADC_INTENR_INTEN BIT(0) 63 64 #define RCAR_GYROADC_SAMPLE_RATE 800 /* Hz */ 65 66 #define RCAR_GYROADC_RUNTIME_PM_DELAY_MS 2000 67 68 enum rcar_gyroadc_model { 69 RCAR_GYROADC_MODEL_DEFAULT, 70 RCAR_GYROADC_MODEL_R8A7792, 71 }; 72 73 struct rcar_gyroadc { 74 struct device *dev; 75 void __iomem *regs; 76 struct clk *clk; 77 struct regulator *vref[8]; 78 unsigned int num_channels; 79 enum rcar_gyroadc_model model; 80 unsigned int mode; 81 unsigned int sample_width; 82 }; 83 84 static void rcar_gyroadc_hw_init(struct rcar_gyroadc *priv) 85 { 86 const unsigned long clk_mhz = clk_get_rate(priv->clk) / 1000000; 87 const unsigned long clk_mul = 88 (priv->mode == RCAR_GYROADC_MODE_SELECT_1_MB88101A) ? 10 : 5; 89 unsigned long clk_len = clk_mhz * clk_mul; 90 91 /* 92 * According to the R-Car Gen2 datasheet Rev. 1.01, Sept 08 2014, 93 * page 77-7, clock length must be even number. If it's odd number, 94 * add one. 95 */ 96 if (clk_len & 1) 97 clk_len++; 98 99 /* Stop the GyroADC. */ 100 writel(0, priv->regs + RCAR_GYROADC_START_STOP); 101 102 /* Disable IRQ on V2H. */ 103 if (priv->model == RCAR_GYROADC_MODEL_R8A7792) 104 writel(0, priv->regs + RCAR_GYROADC_INTENR); 105 106 /* Set mode and timing. */ 107 writel(priv->mode, priv->regs + RCAR_GYROADC_MODE_SELECT); 108 writel(clk_len, priv->regs + RCAR_GYROADC_CLOCK_LENGTH); 109 writel(clk_mhz * 1250, priv->regs + RCAR_GYROADC_1_25MS_LENGTH); 110 } 111 112 static void rcar_gyroadc_hw_start(struct rcar_gyroadc *priv) 113 { 114 /* Start sampling. */ 115 writel(RCAR_GYROADC_START_STOP_START, 116 priv->regs + RCAR_GYROADC_START_STOP); 117 118 /* 119 * Wait for the first conversion to complete. This is longer than 120 * the 1.25 mS in the datasheet because 1.25 mS is not enough for 121 * the hardware to deliver the first sample and the hardware does 122 * then return zeroes instead of valid data. 123 */ 124 mdelay(3); 125 } 126 127 static void rcar_gyroadc_hw_stop(struct rcar_gyroadc *priv) 128 { 129 /* Stop the GyroADC. */ 130 writel(0, priv->regs + RCAR_GYROADC_START_STOP); 131 } 132 133 #define RCAR_GYROADC_CHAN(_idx) { \ 134 .type = IIO_VOLTAGE, \ 135 .indexed = 1, \ 136 .channel = (_idx), \ 137 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \ 138 BIT(IIO_CHAN_INFO_SCALE), \ 139 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SAMP_FREQ), \ 140 } 141 142 static const struct iio_chan_spec rcar_gyroadc_iio_channels_1[] = { 143 RCAR_GYROADC_CHAN(0), 144 RCAR_GYROADC_CHAN(1), 145 RCAR_GYROADC_CHAN(2), 146 RCAR_GYROADC_CHAN(3), 147 }; 148 149 static const struct iio_chan_spec rcar_gyroadc_iio_channels_2[] = { 150 RCAR_GYROADC_CHAN(0), 151 RCAR_GYROADC_CHAN(1), 152 RCAR_GYROADC_CHAN(2), 153 RCAR_GYROADC_CHAN(3), 154 RCAR_GYROADC_CHAN(4), 155 RCAR_GYROADC_CHAN(5), 156 RCAR_GYROADC_CHAN(6), 157 RCAR_GYROADC_CHAN(7), 158 }; 159 160 static const struct iio_chan_spec rcar_gyroadc_iio_channels_3[] = { 161 RCAR_GYROADC_CHAN(0), 162 RCAR_GYROADC_CHAN(1), 163 RCAR_GYROADC_CHAN(2), 164 RCAR_GYROADC_CHAN(3), 165 RCAR_GYROADC_CHAN(4), 166 RCAR_GYROADC_CHAN(5), 167 RCAR_GYROADC_CHAN(6), 168 RCAR_GYROADC_CHAN(7), 169 }; 170 171 static int rcar_gyroadc_set_power(struct rcar_gyroadc *priv, bool on) 172 { 173 struct device *dev = priv->dev; 174 int ret; 175 176 if (on) { 177 ret = pm_runtime_get_sync(dev); 178 if (ret < 0) 179 pm_runtime_put_noidle(dev); 180 } else { 181 pm_runtime_mark_last_busy(dev); 182 ret = pm_runtime_put_autosuspend(dev); 183 } 184 185 return ret; 186 } 187 188 static int rcar_gyroadc_read_raw(struct iio_dev *indio_dev, 189 struct iio_chan_spec const *chan, 190 int *val, int *val2, long mask) 191 { 192 struct rcar_gyroadc *priv = iio_priv(indio_dev); 193 struct regulator *consumer; 194 unsigned int datareg = RCAR_GYROADC_REALTIME_DATA(chan->channel); 195 unsigned int vref; 196 int ret; 197 198 /* 199 * MB88101 is special in that it has only single regulator for 200 * all four channels. 201 */ 202 if (priv->mode == RCAR_GYROADC_MODE_SELECT_1_MB88101A) 203 consumer = priv->vref[0]; 204 else 205 consumer = priv->vref[chan->channel]; 206 207 switch (mask) { 208 case IIO_CHAN_INFO_RAW: 209 if (chan->type != IIO_VOLTAGE) 210 return -EINVAL; 211 212 /* Channel not connected. */ 213 if (!consumer) 214 return -EINVAL; 215 216 ret = iio_device_claim_direct_mode(indio_dev); 217 if (ret) 218 return ret; 219 220 ret = rcar_gyroadc_set_power(priv, true); 221 if (ret < 0) { 222 iio_device_release_direct_mode(indio_dev); 223 return ret; 224 } 225 226 *val = readl(priv->regs + datareg); 227 *val &= BIT(priv->sample_width) - 1; 228 229 ret = rcar_gyroadc_set_power(priv, false); 230 iio_device_release_direct_mode(indio_dev); 231 if (ret < 0) 232 return ret; 233 234 return IIO_VAL_INT; 235 case IIO_CHAN_INFO_SCALE: 236 /* Channel not connected. */ 237 if (!consumer) 238 return -EINVAL; 239 240 vref = regulator_get_voltage(consumer); 241 *val = vref / 1000; 242 *val2 = 1 << priv->sample_width; 243 244 return IIO_VAL_FRACTIONAL; 245 case IIO_CHAN_INFO_SAMP_FREQ: 246 *val = RCAR_GYROADC_SAMPLE_RATE; 247 248 return IIO_VAL_INT; 249 default: 250 return -EINVAL; 251 } 252 } 253 254 static int rcar_gyroadc_reg_access(struct iio_dev *indio_dev, 255 unsigned int reg, unsigned int writeval, 256 unsigned int *readval) 257 { 258 struct rcar_gyroadc *priv = iio_priv(indio_dev); 259 unsigned int maxreg = RCAR_GYROADC_FIFO_STATUS; 260 261 if (readval == NULL) 262 return -EINVAL; 263 264 if (reg % 4) 265 return -EINVAL; 266 267 /* Handle the V2H case with extra interrupt block. */ 268 if (priv->model == RCAR_GYROADC_MODEL_R8A7792) 269 maxreg = RCAR_GYROADC_INTENR; 270 271 if (reg > maxreg) 272 return -EINVAL; 273 274 *readval = readl(priv->regs + reg); 275 276 return 0; 277 } 278 279 static const struct iio_info rcar_gyroadc_iio_info = { 280 .driver_module = THIS_MODULE, 281 .read_raw = rcar_gyroadc_read_raw, 282 .debugfs_reg_access = rcar_gyroadc_reg_access, 283 }; 284 285 static const struct of_device_id rcar_gyroadc_match[] = { 286 { 287 /* R-Car compatible GyroADC */ 288 .compatible = "renesas,rcar-gyroadc", 289 .data = (void *)RCAR_GYROADC_MODEL_DEFAULT, 290 }, { 291 /* R-Car V2H specialty with interrupt registers. */ 292 .compatible = "renesas,r8a7792-gyroadc", 293 .data = (void *)RCAR_GYROADC_MODEL_R8A7792, 294 }, { 295 /* sentinel */ 296 } 297 }; 298 299 MODULE_DEVICE_TABLE(of, rcar_gyroadc_match); 300 301 static const struct of_device_id rcar_gyroadc_child_match[] = { 302 /* Mode 1 ADCs */ 303 { 304 .compatible = "fujitsu,mb88101a", 305 .data = (void *)RCAR_GYROADC_MODE_SELECT_1_MB88101A, 306 }, 307 /* Mode 2 ADCs */ 308 { 309 .compatible = "ti,adcs7476", 310 .data = (void *)RCAR_GYROADC_MODE_SELECT_2_ADCS7476, 311 }, { 312 .compatible = "ti,adc121", 313 .data = (void *)RCAR_GYROADC_MODE_SELECT_2_ADCS7476, 314 }, { 315 .compatible = "adi,ad7476", 316 .data = (void *)RCAR_GYROADC_MODE_SELECT_2_ADCS7476, 317 }, 318 /* Mode 3 ADCs */ 319 { 320 .compatible = "maxim,max1162", 321 .data = (void *)RCAR_GYROADC_MODE_SELECT_3_MAX1162, 322 }, { 323 .compatible = "maxim,max11100", 324 .data = (void *)RCAR_GYROADC_MODE_SELECT_3_MAX1162, 325 }, 326 { /* sentinel */ } 327 }; 328 329 static int rcar_gyroadc_parse_subdevs(struct iio_dev *indio_dev) 330 { 331 const struct of_device_id *of_id; 332 const struct iio_chan_spec *channels; 333 struct rcar_gyroadc *priv = iio_priv(indio_dev); 334 struct device *dev = priv->dev; 335 struct device_node *np = dev->of_node; 336 struct device_node *child; 337 struct regulator *vref; 338 unsigned int reg; 339 unsigned int adcmode = -1, childmode; 340 unsigned int sample_width; 341 unsigned int num_channels; 342 int ret, first = 1; 343 344 for_each_child_of_node(np, child) { 345 of_id = of_match_node(rcar_gyroadc_child_match, child); 346 if (!of_id) { 347 dev_err(dev, "Ignoring unsupported ADC \"%s\".", 348 child->name); 349 continue; 350 } 351 352 childmode = (unsigned int)of_id->data; 353 switch (childmode) { 354 case RCAR_GYROADC_MODE_SELECT_1_MB88101A: 355 sample_width = 12; 356 channels = rcar_gyroadc_iio_channels_1; 357 num_channels = ARRAY_SIZE(rcar_gyroadc_iio_channels_1); 358 break; 359 case RCAR_GYROADC_MODE_SELECT_2_ADCS7476: 360 sample_width = 15; 361 channels = rcar_gyroadc_iio_channels_2; 362 num_channels = ARRAY_SIZE(rcar_gyroadc_iio_channels_2); 363 break; 364 case RCAR_GYROADC_MODE_SELECT_3_MAX1162: 365 sample_width = 16; 366 channels = rcar_gyroadc_iio_channels_3; 367 num_channels = ARRAY_SIZE(rcar_gyroadc_iio_channels_3); 368 break; 369 default: 370 return -EINVAL; 371 } 372 373 /* 374 * MB88101 is special in that it's only a single chip taking 375 * up all the CHS lines. Thus, the DT binding is also special 376 * and has no reg property. If we run into such ADC, handle 377 * it here. 378 */ 379 if (childmode == RCAR_GYROADC_MODE_SELECT_1_MB88101A) { 380 reg = 0; 381 } else { 382 ret = of_property_read_u32(child, "reg", ®); 383 if (ret) { 384 dev_err(dev, 385 "Failed to get child reg property of ADC \"%s\".\n", 386 child->name); 387 return ret; 388 } 389 390 /* Channel number is too high. */ 391 if (reg >= num_channels) { 392 dev_err(dev, 393 "Only %i channels supported with %s, but reg = <%i>.\n", 394 num_channels, child->name, reg); 395 return ret; 396 } 397 } 398 399 /* Child node selected different mode than the rest. */ 400 if (!first && (adcmode != childmode)) { 401 dev_err(dev, 402 "Channel %i uses different ADC mode than the rest.\n", 403 reg); 404 return ret; 405 } 406 407 /* Channel is valid, grab the regulator. */ 408 dev->of_node = child; 409 vref = devm_regulator_get(dev, "vref"); 410 dev->of_node = np; 411 if (IS_ERR(vref)) { 412 dev_dbg(dev, "Channel %i 'vref' supply not connected.\n", 413 reg); 414 return PTR_ERR(vref); 415 } 416 417 priv->vref[reg] = vref; 418 419 if (!first) 420 continue; 421 422 /* First child node which passed sanity tests. */ 423 adcmode = childmode; 424 first = 0; 425 426 priv->num_channels = num_channels; 427 priv->mode = childmode; 428 priv->sample_width = sample_width; 429 430 indio_dev->channels = channels; 431 indio_dev->num_channels = num_channels; 432 433 /* 434 * MB88101 is special and we only have one such device 435 * attached to the GyroADC at a time, so if we found it, 436 * we can stop parsing here. 437 */ 438 if (childmode == RCAR_GYROADC_MODE_SELECT_1_MB88101A) 439 break; 440 } 441 442 if (first) { 443 dev_err(dev, "No valid ADC channels found, aborting.\n"); 444 return -EINVAL; 445 } 446 447 return 0; 448 } 449 450 static void rcar_gyroadc_deinit_supplies(struct iio_dev *indio_dev) 451 { 452 struct rcar_gyroadc *priv = iio_priv(indio_dev); 453 unsigned int i; 454 455 for (i = 0; i < priv->num_channels; i++) { 456 if (!priv->vref[i]) 457 continue; 458 459 regulator_disable(priv->vref[i]); 460 } 461 } 462 463 static int rcar_gyroadc_init_supplies(struct iio_dev *indio_dev) 464 { 465 struct rcar_gyroadc *priv = iio_priv(indio_dev); 466 struct device *dev = priv->dev; 467 unsigned int i; 468 int ret; 469 470 for (i = 0; i < priv->num_channels; i++) { 471 if (!priv->vref[i]) 472 continue; 473 474 ret = regulator_enable(priv->vref[i]); 475 if (ret) { 476 dev_err(dev, "Failed to enable regulator %i (ret=%i)\n", 477 i, ret); 478 goto err; 479 } 480 } 481 482 return 0; 483 484 err: 485 rcar_gyroadc_deinit_supplies(indio_dev); 486 return ret; 487 } 488 489 static int rcar_gyroadc_probe(struct platform_device *pdev) 490 { 491 const struct of_device_id *of_id = 492 of_match_device(rcar_gyroadc_match, &pdev->dev); 493 struct device *dev = &pdev->dev; 494 struct rcar_gyroadc *priv; 495 struct iio_dev *indio_dev; 496 struct resource *mem; 497 int ret; 498 499 indio_dev = devm_iio_device_alloc(dev, sizeof(*priv)); 500 if (!indio_dev) { 501 dev_err(dev, "Failed to allocate IIO device.\n"); 502 return -ENOMEM; 503 } 504 505 priv = iio_priv(indio_dev); 506 priv->dev = dev; 507 508 mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); 509 priv->regs = devm_ioremap_resource(dev, mem); 510 if (IS_ERR(priv->regs)) 511 return PTR_ERR(priv->regs); 512 513 priv->clk = devm_clk_get(dev, "fck"); 514 if (IS_ERR(priv->clk)) { 515 ret = PTR_ERR(priv->clk); 516 if (ret != -EPROBE_DEFER) 517 dev_err(dev, "Failed to get IF clock (ret=%i)\n", ret); 518 return ret; 519 } 520 521 ret = rcar_gyroadc_parse_subdevs(indio_dev); 522 if (ret) 523 return ret; 524 525 ret = rcar_gyroadc_init_supplies(indio_dev); 526 if (ret) 527 return ret; 528 529 priv->model = (enum rcar_gyroadc_model)of_id->data; 530 531 platform_set_drvdata(pdev, indio_dev); 532 533 indio_dev->name = DRIVER_NAME; 534 indio_dev->dev.parent = dev; 535 indio_dev->dev.of_node = pdev->dev.of_node; 536 indio_dev->info = &rcar_gyroadc_iio_info; 537 indio_dev->modes = INDIO_DIRECT_MODE; 538 539 ret = clk_prepare_enable(priv->clk); 540 if (ret) { 541 dev_err(dev, "Could not prepare or enable the IF clock.\n"); 542 goto err_clk_if_enable; 543 } 544 545 pm_runtime_set_autosuspend_delay(dev, RCAR_GYROADC_RUNTIME_PM_DELAY_MS); 546 pm_runtime_use_autosuspend(dev); 547 pm_runtime_enable(dev); 548 549 pm_runtime_get_sync(dev); 550 rcar_gyroadc_hw_init(priv); 551 rcar_gyroadc_hw_start(priv); 552 553 ret = iio_device_register(indio_dev); 554 if (ret) { 555 dev_err(dev, "Couldn't register IIO device.\n"); 556 goto err_iio_device_register; 557 } 558 559 pm_runtime_put_sync(dev); 560 561 return 0; 562 563 err_iio_device_register: 564 rcar_gyroadc_hw_stop(priv); 565 pm_runtime_put_sync(dev); 566 pm_runtime_disable(dev); 567 pm_runtime_set_suspended(dev); 568 clk_disable_unprepare(priv->clk); 569 err_clk_if_enable: 570 rcar_gyroadc_deinit_supplies(indio_dev); 571 572 return ret; 573 } 574 575 static int rcar_gyroadc_remove(struct platform_device *pdev) 576 { 577 struct iio_dev *indio_dev = platform_get_drvdata(pdev); 578 struct rcar_gyroadc *priv = iio_priv(indio_dev); 579 struct device *dev = priv->dev; 580 581 iio_device_unregister(indio_dev); 582 pm_runtime_get_sync(dev); 583 rcar_gyroadc_hw_stop(priv); 584 pm_runtime_put_sync(dev); 585 pm_runtime_disable(dev); 586 pm_runtime_set_suspended(dev); 587 clk_disable_unprepare(priv->clk); 588 rcar_gyroadc_deinit_supplies(indio_dev); 589 590 return 0; 591 } 592 593 #if defined(CONFIG_PM) 594 static int rcar_gyroadc_suspend(struct device *dev) 595 { 596 struct iio_dev *indio_dev = dev_get_drvdata(dev); 597 struct rcar_gyroadc *priv = iio_priv(indio_dev); 598 599 rcar_gyroadc_hw_stop(priv); 600 601 return 0; 602 } 603 604 static int rcar_gyroadc_resume(struct device *dev) 605 { 606 struct iio_dev *indio_dev = dev_get_drvdata(dev); 607 struct rcar_gyroadc *priv = iio_priv(indio_dev); 608 609 rcar_gyroadc_hw_start(priv); 610 611 return 0; 612 } 613 #endif 614 615 static const struct dev_pm_ops rcar_gyroadc_pm_ops = { 616 SET_RUNTIME_PM_OPS(rcar_gyroadc_suspend, rcar_gyroadc_resume, NULL) 617 }; 618 619 static struct platform_driver rcar_gyroadc_driver = { 620 .probe = rcar_gyroadc_probe, 621 .remove = rcar_gyroadc_remove, 622 .driver = { 623 .name = DRIVER_NAME, 624 .of_match_table = rcar_gyroadc_match, 625 .pm = &rcar_gyroadc_pm_ops, 626 }, 627 }; 628 629 module_platform_driver(rcar_gyroadc_driver); 630 631 MODULE_AUTHOR("Marek Vasut <marek.vasut@gmail.com>"); 632 MODULE_DESCRIPTION("Renesas R-Car GyroADC driver"); 633 MODULE_LICENSE("GPL"); 634