1 // SPDX-License-Identifier: GPL-2.0+ 2 /* 3 * Renesas R-Car GyroADC driver 4 * 5 * Copyright 2016 Marek Vasut <marek.vasut@gmail.com> 6 */ 7 8 #include <linux/module.h> 9 #include <linux/platform_device.h> 10 #include <linux/delay.h> 11 #include <linux/kernel.h> 12 #include <linux/slab.h> 13 #include <linux/io.h> 14 #include <linux/clk.h> 15 #include <linux/of.h> 16 #include <linux/of_irq.h> 17 #include <linux/regulator/consumer.h> 18 #include <linux/of_platform.h> 19 #include <linux/err.h> 20 #include <linux/pm_runtime.h> 21 22 #include <linux/iio/iio.h> 23 #include <linux/iio/sysfs.h> 24 #include <linux/iio/trigger.h> 25 26 #define DRIVER_NAME "rcar-gyroadc" 27 28 /* GyroADC registers. */ 29 #define RCAR_GYROADC_MODE_SELECT 0x00 30 #define RCAR_GYROADC_MODE_SELECT_1_MB88101A 0x0 31 #define RCAR_GYROADC_MODE_SELECT_2_ADCS7476 0x1 32 #define RCAR_GYROADC_MODE_SELECT_3_MAX1162 0x3 33 34 #define RCAR_GYROADC_START_STOP 0x04 35 #define RCAR_GYROADC_START_STOP_START BIT(0) 36 37 #define RCAR_GYROADC_CLOCK_LENGTH 0x08 38 #define RCAR_GYROADC_1_25MS_LENGTH 0x0c 39 40 #define RCAR_GYROADC_REALTIME_DATA(ch) (0x10 + ((ch) * 4)) 41 #define RCAR_GYROADC_100MS_ADDED_DATA(ch) (0x30 + ((ch) * 4)) 42 #define RCAR_GYROADC_10MS_AVG_DATA(ch) (0x50 + ((ch) * 4)) 43 44 #define RCAR_GYROADC_FIFO_STATUS 0x70 45 #define RCAR_GYROADC_FIFO_STATUS_EMPTY(ch) BIT(0 + (4 * (ch))) 46 #define RCAR_GYROADC_FIFO_STATUS_FULL(ch) BIT(1 + (4 * (ch))) 47 #define RCAR_GYROADC_FIFO_STATUS_ERROR(ch) BIT(2 + (4 * (ch))) 48 49 #define RCAR_GYROADC_INTR 0x74 50 #define RCAR_GYROADC_INTR_INT BIT(0) 51 52 #define RCAR_GYROADC_INTENR 0x78 53 #define RCAR_GYROADC_INTENR_INTEN BIT(0) 54 55 #define RCAR_GYROADC_SAMPLE_RATE 800 /* Hz */ 56 57 #define RCAR_GYROADC_RUNTIME_PM_DELAY_MS 2000 58 59 enum rcar_gyroadc_model { 60 RCAR_GYROADC_MODEL_DEFAULT, 61 RCAR_GYROADC_MODEL_R8A7792, 62 }; 63 64 struct rcar_gyroadc { 65 struct device *dev; 66 void __iomem *regs; 67 struct clk *clk; 68 struct regulator *vref[8]; 69 unsigned int num_channels; 70 enum rcar_gyroadc_model model; 71 unsigned int mode; 72 unsigned int sample_width; 73 }; 74 75 static void rcar_gyroadc_hw_init(struct rcar_gyroadc *priv) 76 { 77 const unsigned long clk_mhz = clk_get_rate(priv->clk) / 1000000; 78 const unsigned long clk_mul = 79 (priv->mode == RCAR_GYROADC_MODE_SELECT_1_MB88101A) ? 10 : 5; 80 unsigned long clk_len = clk_mhz * clk_mul; 81 82 /* 83 * According to the R-Car Gen2 datasheet Rev. 1.01, Sept 08 2014, 84 * page 77-7, clock length must be even number. If it's odd number, 85 * add one. 86 */ 87 if (clk_len & 1) 88 clk_len++; 89 90 /* Stop the GyroADC. */ 91 writel(0, priv->regs + RCAR_GYROADC_START_STOP); 92 93 /* Disable IRQ on V2H. */ 94 if (priv->model == RCAR_GYROADC_MODEL_R8A7792) 95 writel(0, priv->regs + RCAR_GYROADC_INTENR); 96 97 /* Set mode and timing. */ 98 writel(priv->mode, priv->regs + RCAR_GYROADC_MODE_SELECT); 99 writel(clk_len, priv->regs + RCAR_GYROADC_CLOCK_LENGTH); 100 writel(clk_mhz * 1250, priv->regs + RCAR_GYROADC_1_25MS_LENGTH); 101 } 102 103 static void rcar_gyroadc_hw_start(struct rcar_gyroadc *priv) 104 { 105 /* Start sampling. */ 106 writel(RCAR_GYROADC_START_STOP_START, 107 priv->regs + RCAR_GYROADC_START_STOP); 108 109 /* 110 * Wait for the first conversion to complete. This is longer than 111 * the 1.25 mS in the datasheet because 1.25 mS is not enough for 112 * the hardware to deliver the first sample and the hardware does 113 * then return zeroes instead of valid data. 114 */ 115 mdelay(3); 116 } 117 118 static void rcar_gyroadc_hw_stop(struct rcar_gyroadc *priv) 119 { 120 /* Stop the GyroADC. */ 121 writel(0, priv->regs + RCAR_GYROADC_START_STOP); 122 } 123 124 #define RCAR_GYROADC_CHAN(_idx) { \ 125 .type = IIO_VOLTAGE, \ 126 .indexed = 1, \ 127 .channel = (_idx), \ 128 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \ 129 BIT(IIO_CHAN_INFO_SCALE), \ 130 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SAMP_FREQ), \ 131 } 132 133 static const struct iio_chan_spec rcar_gyroadc_iio_channels_1[] = { 134 RCAR_GYROADC_CHAN(0), 135 RCAR_GYROADC_CHAN(1), 136 RCAR_GYROADC_CHAN(2), 137 RCAR_GYROADC_CHAN(3), 138 }; 139 140 static const struct iio_chan_spec rcar_gyroadc_iio_channels_2[] = { 141 RCAR_GYROADC_CHAN(0), 142 RCAR_GYROADC_CHAN(1), 143 RCAR_GYROADC_CHAN(2), 144 RCAR_GYROADC_CHAN(3), 145 RCAR_GYROADC_CHAN(4), 146 RCAR_GYROADC_CHAN(5), 147 RCAR_GYROADC_CHAN(6), 148 RCAR_GYROADC_CHAN(7), 149 }; 150 151 static const struct iio_chan_spec rcar_gyroadc_iio_channels_3[] = { 152 RCAR_GYROADC_CHAN(0), 153 RCAR_GYROADC_CHAN(1), 154 RCAR_GYROADC_CHAN(2), 155 RCAR_GYROADC_CHAN(3), 156 RCAR_GYROADC_CHAN(4), 157 RCAR_GYROADC_CHAN(5), 158 RCAR_GYROADC_CHAN(6), 159 RCAR_GYROADC_CHAN(7), 160 }; 161 162 static int rcar_gyroadc_set_power(struct rcar_gyroadc *priv, bool on) 163 { 164 struct device *dev = priv->dev; 165 int ret; 166 167 if (on) { 168 ret = pm_runtime_get_sync(dev); 169 if (ret < 0) 170 pm_runtime_put_noidle(dev); 171 } else { 172 pm_runtime_mark_last_busy(dev); 173 ret = pm_runtime_put_autosuspend(dev); 174 } 175 176 return ret; 177 } 178 179 static int rcar_gyroadc_read_raw(struct iio_dev *indio_dev, 180 struct iio_chan_spec const *chan, 181 int *val, int *val2, long mask) 182 { 183 struct rcar_gyroadc *priv = iio_priv(indio_dev); 184 struct regulator *consumer; 185 unsigned int datareg = RCAR_GYROADC_REALTIME_DATA(chan->channel); 186 unsigned int vref; 187 int ret; 188 189 /* 190 * MB88101 is special in that it has only single regulator for 191 * all four channels. 192 */ 193 if (priv->mode == RCAR_GYROADC_MODE_SELECT_1_MB88101A) 194 consumer = priv->vref[0]; 195 else 196 consumer = priv->vref[chan->channel]; 197 198 switch (mask) { 199 case IIO_CHAN_INFO_RAW: 200 if (chan->type != IIO_VOLTAGE) 201 return -EINVAL; 202 203 /* Channel not connected. */ 204 if (!consumer) 205 return -EINVAL; 206 207 ret = iio_device_claim_direct_mode(indio_dev); 208 if (ret) 209 return ret; 210 211 ret = rcar_gyroadc_set_power(priv, true); 212 if (ret < 0) { 213 iio_device_release_direct_mode(indio_dev); 214 return ret; 215 } 216 217 *val = readl(priv->regs + datareg); 218 *val &= BIT(priv->sample_width) - 1; 219 220 ret = rcar_gyroadc_set_power(priv, false); 221 iio_device_release_direct_mode(indio_dev); 222 if (ret < 0) 223 return ret; 224 225 return IIO_VAL_INT; 226 case IIO_CHAN_INFO_SCALE: 227 /* Channel not connected. */ 228 if (!consumer) 229 return -EINVAL; 230 231 vref = regulator_get_voltage(consumer); 232 *val = vref / 1000; 233 *val2 = 1 << priv->sample_width; 234 235 return IIO_VAL_FRACTIONAL; 236 case IIO_CHAN_INFO_SAMP_FREQ: 237 *val = RCAR_GYROADC_SAMPLE_RATE; 238 239 return IIO_VAL_INT; 240 default: 241 return -EINVAL; 242 } 243 } 244 245 static int rcar_gyroadc_reg_access(struct iio_dev *indio_dev, 246 unsigned int reg, unsigned int writeval, 247 unsigned int *readval) 248 { 249 struct rcar_gyroadc *priv = iio_priv(indio_dev); 250 unsigned int maxreg = RCAR_GYROADC_FIFO_STATUS; 251 252 if (readval == NULL) 253 return -EINVAL; 254 255 if (reg % 4) 256 return -EINVAL; 257 258 /* Handle the V2H case with extra interrupt block. */ 259 if (priv->model == RCAR_GYROADC_MODEL_R8A7792) 260 maxreg = RCAR_GYROADC_INTENR; 261 262 if (reg > maxreg) 263 return -EINVAL; 264 265 *readval = readl(priv->regs + reg); 266 267 return 0; 268 } 269 270 static const struct iio_info rcar_gyroadc_iio_info = { 271 .read_raw = rcar_gyroadc_read_raw, 272 .debugfs_reg_access = rcar_gyroadc_reg_access, 273 }; 274 275 static const struct of_device_id rcar_gyroadc_match[] = { 276 { 277 /* R-Car compatible GyroADC */ 278 .compatible = "renesas,rcar-gyroadc", 279 .data = (void *)RCAR_GYROADC_MODEL_DEFAULT, 280 }, { 281 /* R-Car V2H specialty with interrupt registers. */ 282 .compatible = "renesas,r8a7792-gyroadc", 283 .data = (void *)RCAR_GYROADC_MODEL_R8A7792, 284 }, { 285 /* sentinel */ 286 } 287 }; 288 289 MODULE_DEVICE_TABLE(of, rcar_gyroadc_match); 290 291 static const struct of_device_id rcar_gyroadc_child_match[] = { 292 /* Mode 1 ADCs */ 293 { 294 .compatible = "fujitsu,mb88101a", 295 .data = (void *)RCAR_GYROADC_MODE_SELECT_1_MB88101A, 296 }, 297 /* Mode 2 ADCs */ 298 { 299 .compatible = "ti,adcs7476", 300 .data = (void *)RCAR_GYROADC_MODE_SELECT_2_ADCS7476, 301 }, { 302 .compatible = "ti,adc121", 303 .data = (void *)RCAR_GYROADC_MODE_SELECT_2_ADCS7476, 304 }, { 305 .compatible = "adi,ad7476", 306 .data = (void *)RCAR_GYROADC_MODE_SELECT_2_ADCS7476, 307 }, 308 /* Mode 3 ADCs */ 309 { 310 .compatible = "maxim,max1162", 311 .data = (void *)RCAR_GYROADC_MODE_SELECT_3_MAX1162, 312 }, { 313 .compatible = "maxim,max11100", 314 .data = (void *)RCAR_GYROADC_MODE_SELECT_3_MAX1162, 315 }, 316 { /* sentinel */ } 317 }; 318 319 static int rcar_gyroadc_parse_subdevs(struct iio_dev *indio_dev) 320 { 321 const struct of_device_id *of_id; 322 const struct iio_chan_spec *channels; 323 struct rcar_gyroadc *priv = iio_priv(indio_dev); 324 struct device *dev = priv->dev; 325 struct device_node *np = dev->of_node; 326 struct device_node *child; 327 struct regulator *vref; 328 unsigned int reg; 329 unsigned int adcmode = -1, childmode; 330 unsigned int sample_width; 331 unsigned int num_channels; 332 int ret, first = 1; 333 334 for_each_child_of_node(np, child) { 335 of_id = of_match_node(rcar_gyroadc_child_match, child); 336 if (!of_id) { 337 dev_err(dev, "Ignoring unsupported ADC \"%pOFn\".", 338 child); 339 continue; 340 } 341 342 childmode = (uintptr_t)of_id->data; 343 switch (childmode) { 344 case RCAR_GYROADC_MODE_SELECT_1_MB88101A: 345 sample_width = 12; 346 channels = rcar_gyroadc_iio_channels_1; 347 num_channels = ARRAY_SIZE(rcar_gyroadc_iio_channels_1); 348 break; 349 case RCAR_GYROADC_MODE_SELECT_2_ADCS7476: 350 sample_width = 15; 351 channels = rcar_gyroadc_iio_channels_2; 352 num_channels = ARRAY_SIZE(rcar_gyroadc_iio_channels_2); 353 break; 354 case RCAR_GYROADC_MODE_SELECT_3_MAX1162: 355 sample_width = 16; 356 channels = rcar_gyroadc_iio_channels_3; 357 num_channels = ARRAY_SIZE(rcar_gyroadc_iio_channels_3); 358 break; 359 default: 360 return -EINVAL; 361 } 362 363 /* 364 * MB88101 is special in that it's only a single chip taking 365 * up all the CHS lines. Thus, the DT binding is also special 366 * and has no reg property. If we run into such ADC, handle 367 * it here. 368 */ 369 if (childmode == RCAR_GYROADC_MODE_SELECT_1_MB88101A) { 370 reg = 0; 371 } else { 372 ret = of_property_read_u32(child, "reg", ®); 373 if (ret) { 374 dev_err(dev, 375 "Failed to get child reg property of ADC \"%pOFn\".\n", 376 child); 377 return ret; 378 } 379 380 /* Channel number is too high. */ 381 if (reg >= num_channels) { 382 dev_err(dev, 383 "Only %i channels supported with %pOFn, but reg = <%i>.\n", 384 num_channels, child, reg); 385 return -EINVAL; 386 } 387 } 388 389 /* Child node selected different mode than the rest. */ 390 if (!first && (adcmode != childmode)) { 391 dev_err(dev, 392 "Channel %i uses different ADC mode than the rest.\n", 393 reg); 394 return -EINVAL; 395 } 396 397 /* Channel is valid, grab the regulator. */ 398 dev->of_node = child; 399 vref = devm_regulator_get(dev, "vref"); 400 dev->of_node = np; 401 if (IS_ERR(vref)) { 402 dev_dbg(dev, "Channel %i 'vref' supply not connected.\n", 403 reg); 404 return PTR_ERR(vref); 405 } 406 407 priv->vref[reg] = vref; 408 409 if (!first) 410 continue; 411 412 /* First child node which passed sanity tests. */ 413 adcmode = childmode; 414 first = 0; 415 416 priv->num_channels = num_channels; 417 priv->mode = childmode; 418 priv->sample_width = sample_width; 419 420 indio_dev->channels = channels; 421 indio_dev->num_channels = num_channels; 422 423 /* 424 * MB88101 is special and we only have one such device 425 * attached to the GyroADC at a time, so if we found it, 426 * we can stop parsing here. 427 */ 428 if (childmode == RCAR_GYROADC_MODE_SELECT_1_MB88101A) 429 break; 430 } 431 432 if (first) { 433 dev_err(dev, "No valid ADC channels found, aborting.\n"); 434 return -EINVAL; 435 } 436 437 return 0; 438 } 439 440 static void rcar_gyroadc_deinit_supplies(struct iio_dev *indio_dev) 441 { 442 struct rcar_gyroadc *priv = iio_priv(indio_dev); 443 unsigned int i; 444 445 for (i = 0; i < priv->num_channels; i++) { 446 if (!priv->vref[i]) 447 continue; 448 449 regulator_disable(priv->vref[i]); 450 } 451 } 452 453 static int rcar_gyroadc_init_supplies(struct iio_dev *indio_dev) 454 { 455 struct rcar_gyroadc *priv = iio_priv(indio_dev); 456 struct device *dev = priv->dev; 457 unsigned int i; 458 int ret; 459 460 for (i = 0; i < priv->num_channels; i++) { 461 if (!priv->vref[i]) 462 continue; 463 464 ret = regulator_enable(priv->vref[i]); 465 if (ret) { 466 dev_err(dev, "Failed to enable regulator %i (ret=%i)\n", 467 i, ret); 468 goto err; 469 } 470 } 471 472 return 0; 473 474 err: 475 rcar_gyroadc_deinit_supplies(indio_dev); 476 return ret; 477 } 478 479 static int rcar_gyroadc_probe(struct platform_device *pdev) 480 { 481 struct device *dev = &pdev->dev; 482 struct rcar_gyroadc *priv; 483 struct iio_dev *indio_dev; 484 int ret; 485 486 indio_dev = devm_iio_device_alloc(dev, sizeof(*priv)); 487 if (!indio_dev) 488 return -ENOMEM; 489 490 priv = iio_priv(indio_dev); 491 priv->dev = dev; 492 493 priv->regs = devm_platform_ioremap_resource(pdev, 0); 494 if (IS_ERR(priv->regs)) 495 return PTR_ERR(priv->regs); 496 497 priv->clk = devm_clk_get(dev, "fck"); 498 if (IS_ERR(priv->clk)) { 499 ret = PTR_ERR(priv->clk); 500 if (ret != -EPROBE_DEFER) 501 dev_err(dev, "Failed to get IF clock (ret=%i)\n", ret); 502 return ret; 503 } 504 505 ret = rcar_gyroadc_parse_subdevs(indio_dev); 506 if (ret) 507 return ret; 508 509 ret = rcar_gyroadc_init_supplies(indio_dev); 510 if (ret) 511 return ret; 512 513 priv->model = (enum rcar_gyroadc_model) 514 of_device_get_match_data(&pdev->dev); 515 516 platform_set_drvdata(pdev, indio_dev); 517 518 indio_dev->name = DRIVER_NAME; 519 indio_dev->dev.parent = dev; 520 indio_dev->dev.of_node = pdev->dev.of_node; 521 indio_dev->info = &rcar_gyroadc_iio_info; 522 indio_dev->modes = INDIO_DIRECT_MODE; 523 524 ret = clk_prepare_enable(priv->clk); 525 if (ret) { 526 dev_err(dev, "Could not prepare or enable the IF clock.\n"); 527 goto err_clk_if_enable; 528 } 529 530 pm_runtime_set_autosuspend_delay(dev, RCAR_GYROADC_RUNTIME_PM_DELAY_MS); 531 pm_runtime_use_autosuspend(dev); 532 pm_runtime_enable(dev); 533 534 pm_runtime_get_sync(dev); 535 rcar_gyroadc_hw_init(priv); 536 rcar_gyroadc_hw_start(priv); 537 538 ret = iio_device_register(indio_dev); 539 if (ret) { 540 dev_err(dev, "Couldn't register IIO device.\n"); 541 goto err_iio_device_register; 542 } 543 544 pm_runtime_put_sync(dev); 545 546 return 0; 547 548 err_iio_device_register: 549 rcar_gyroadc_hw_stop(priv); 550 pm_runtime_put_sync(dev); 551 pm_runtime_disable(dev); 552 pm_runtime_set_suspended(dev); 553 clk_disable_unprepare(priv->clk); 554 err_clk_if_enable: 555 rcar_gyroadc_deinit_supplies(indio_dev); 556 557 return ret; 558 } 559 560 static int rcar_gyroadc_remove(struct platform_device *pdev) 561 { 562 struct iio_dev *indio_dev = platform_get_drvdata(pdev); 563 struct rcar_gyroadc *priv = iio_priv(indio_dev); 564 struct device *dev = priv->dev; 565 566 iio_device_unregister(indio_dev); 567 pm_runtime_get_sync(dev); 568 rcar_gyroadc_hw_stop(priv); 569 pm_runtime_put_sync(dev); 570 pm_runtime_disable(dev); 571 pm_runtime_set_suspended(dev); 572 clk_disable_unprepare(priv->clk); 573 rcar_gyroadc_deinit_supplies(indio_dev); 574 575 return 0; 576 } 577 578 #if defined(CONFIG_PM) 579 static int rcar_gyroadc_suspend(struct device *dev) 580 { 581 struct iio_dev *indio_dev = dev_get_drvdata(dev); 582 struct rcar_gyroadc *priv = iio_priv(indio_dev); 583 584 rcar_gyroadc_hw_stop(priv); 585 586 return 0; 587 } 588 589 static int rcar_gyroadc_resume(struct device *dev) 590 { 591 struct iio_dev *indio_dev = dev_get_drvdata(dev); 592 struct rcar_gyroadc *priv = iio_priv(indio_dev); 593 594 rcar_gyroadc_hw_start(priv); 595 596 return 0; 597 } 598 #endif 599 600 static const struct dev_pm_ops rcar_gyroadc_pm_ops = { 601 SET_RUNTIME_PM_OPS(rcar_gyroadc_suspend, rcar_gyroadc_resume, NULL) 602 }; 603 604 static struct platform_driver rcar_gyroadc_driver = { 605 .probe = rcar_gyroadc_probe, 606 .remove = rcar_gyroadc_remove, 607 .driver = { 608 .name = DRIVER_NAME, 609 .of_match_table = rcar_gyroadc_match, 610 .pm = &rcar_gyroadc_pm_ops, 611 }, 612 }; 613 614 module_platform_driver(rcar_gyroadc_driver); 615 616 MODULE_AUTHOR("Marek Vasut <marek.vasut@gmail.com>"); 617 MODULE_DESCRIPTION("Renesas R-Car GyroADC driver"); 618 MODULE_LICENSE("GPL"); 619