1 // SPDX-License-Identifier: GPL-2.0 2 // Copyright (C) 2018 Spreadtrum Communications Inc. 3 4 #include <linux/hwspinlock.h> 5 #include <linux/iio/iio.h> 6 #include <linux/module.h> 7 #include <linux/nvmem-consumer.h> 8 #include <linux/of.h> 9 #include <linux/of_device.h> 10 #include <linux/platform_device.h> 11 #include <linux/regmap.h> 12 #include <linux/slab.h> 13 14 /* PMIC global registers definition */ 15 #define SC27XX_MODULE_EN 0xc08 16 #define SC27XX_MODULE_ADC_EN BIT(5) 17 #define SC27XX_ARM_CLK_EN 0xc10 18 #define SC27XX_CLK_ADC_EN BIT(5) 19 #define SC27XX_CLK_ADC_CLK_EN BIT(6) 20 21 /* ADC controller registers definition */ 22 #define SC27XX_ADC_CTL 0x0 23 #define SC27XX_ADC_CH_CFG 0x4 24 #define SC27XX_ADC_DATA 0x4c 25 #define SC27XX_ADC_INT_EN 0x50 26 #define SC27XX_ADC_INT_CLR 0x54 27 #define SC27XX_ADC_INT_STS 0x58 28 #define SC27XX_ADC_INT_RAW 0x5c 29 30 /* Bits and mask definition for SC27XX_ADC_CTL register */ 31 #define SC27XX_ADC_EN BIT(0) 32 #define SC27XX_ADC_CHN_RUN BIT(1) 33 #define SC27XX_ADC_12BIT_MODE BIT(2) 34 #define SC27XX_ADC_RUN_NUM_MASK GENMASK(7, 4) 35 #define SC27XX_ADC_RUN_NUM_SHIFT 4 36 37 /* Bits and mask definition for SC27XX_ADC_CH_CFG register */ 38 #define SC27XX_ADC_CHN_ID_MASK GENMASK(4, 0) 39 #define SC27XX_ADC_SCALE_MASK GENMASK(10, 8) 40 #define SC27XX_ADC_SCALE_SHIFT 8 41 42 /* Bits definitions for SC27XX_ADC_INT_EN registers */ 43 #define SC27XX_ADC_IRQ_EN BIT(0) 44 45 /* Bits definitions for SC27XX_ADC_INT_CLR registers */ 46 #define SC27XX_ADC_IRQ_CLR BIT(0) 47 48 /* Bits definitions for SC27XX_ADC_INT_RAW registers */ 49 #define SC27XX_ADC_IRQ_RAW BIT(0) 50 51 /* Mask definition for SC27XX_ADC_DATA register */ 52 #define SC27XX_ADC_DATA_MASK GENMASK(11, 0) 53 54 /* Timeout (ms) for the trylock of hardware spinlocks */ 55 #define SC27XX_ADC_HWLOCK_TIMEOUT 5000 56 57 /* Timeout (us) for ADC data conversion according to ADC datasheet */ 58 #define SC27XX_ADC_RDY_TIMEOUT 1000000 59 #define SC27XX_ADC_POLL_RAW_STATUS 500 60 61 /* Maximum ADC channel number */ 62 #define SC27XX_ADC_CHANNEL_MAX 32 63 64 /* ADC voltage ratio definition */ 65 #define SC27XX_VOLT_RATIO(n, d) \ 66 (((n) << SC27XX_RATIO_NUMERATOR_OFFSET) | (d)) 67 #define SC27XX_RATIO_NUMERATOR_OFFSET 16 68 #define SC27XX_RATIO_DENOMINATOR_MASK GENMASK(15, 0) 69 70 struct sc27xx_adc_data { 71 struct device *dev; 72 struct regmap *regmap; 73 /* 74 * One hardware spinlock to synchronize between the multiple 75 * subsystems which will access the unique ADC controller. 76 */ 77 struct hwspinlock *hwlock; 78 int channel_scale[SC27XX_ADC_CHANNEL_MAX]; 79 u32 base; 80 int irq; 81 }; 82 83 struct sc27xx_adc_linear_graph { 84 int volt0; 85 int adc0; 86 int volt1; 87 int adc1; 88 }; 89 90 /* 91 * According to the datasheet, we can convert one ADC value to one voltage value 92 * through 2 points in the linear graph. If the voltage is less than 1.2v, we 93 * should use the small-scale graph, and if more than 1.2v, we should use the 94 * big-scale graph. 95 */ 96 static struct sc27xx_adc_linear_graph big_scale_graph = { 97 4200, 3310, 98 3600, 2832, 99 }; 100 101 static struct sc27xx_adc_linear_graph small_scale_graph = { 102 1000, 3413, 103 100, 341, 104 }; 105 106 static const struct sc27xx_adc_linear_graph big_scale_graph_calib = { 107 4200, 856, 108 3600, 733, 109 }; 110 111 static const struct sc27xx_adc_linear_graph small_scale_graph_calib = { 112 1000, 833, 113 100, 80, 114 }; 115 116 static int sc27xx_adc_get_calib_data(u32 calib_data, int calib_adc) 117 { 118 return ((calib_data & 0xff) + calib_adc - 128) * 4; 119 } 120 121 static int sc27xx_adc_scale_calibration(struct sc27xx_adc_data *data, 122 bool big_scale) 123 { 124 const struct sc27xx_adc_linear_graph *calib_graph; 125 struct sc27xx_adc_linear_graph *graph; 126 struct nvmem_cell *cell; 127 const char *cell_name; 128 u32 calib_data = 0; 129 void *buf; 130 size_t len; 131 132 if (big_scale) { 133 calib_graph = &big_scale_graph_calib; 134 graph = &big_scale_graph; 135 cell_name = "big_scale_calib"; 136 } else { 137 calib_graph = &small_scale_graph_calib; 138 graph = &small_scale_graph; 139 cell_name = "small_scale_calib"; 140 } 141 142 cell = nvmem_cell_get(data->dev, cell_name); 143 if (IS_ERR(cell)) 144 return PTR_ERR(cell); 145 146 buf = nvmem_cell_read(cell, &len); 147 nvmem_cell_put(cell); 148 149 if (IS_ERR(buf)) 150 return PTR_ERR(buf); 151 152 memcpy(&calib_data, buf, min(len, sizeof(u32))); 153 154 /* Only need to calibrate the adc values in the linear graph. */ 155 graph->adc0 = sc27xx_adc_get_calib_data(calib_data, calib_graph->adc0); 156 graph->adc1 = sc27xx_adc_get_calib_data(calib_data >> 8, 157 calib_graph->adc1); 158 159 kfree(buf); 160 return 0; 161 } 162 163 static int sc27xx_adc_get_ratio(int channel, int scale) 164 { 165 switch (channel) { 166 case 1: 167 case 2: 168 case 3: 169 case 4: 170 return scale ? SC27XX_VOLT_RATIO(400, 1025) : 171 SC27XX_VOLT_RATIO(1, 1); 172 case 5: 173 return SC27XX_VOLT_RATIO(7, 29); 174 case 6: 175 return SC27XX_VOLT_RATIO(375, 9000); 176 case 7: 177 case 8: 178 return scale ? SC27XX_VOLT_RATIO(100, 125) : 179 SC27XX_VOLT_RATIO(1, 1); 180 case 19: 181 return SC27XX_VOLT_RATIO(1, 3); 182 default: 183 return SC27XX_VOLT_RATIO(1, 1); 184 } 185 return SC27XX_VOLT_RATIO(1, 1); 186 } 187 188 static int sc27xx_adc_read(struct sc27xx_adc_data *data, int channel, 189 int scale, int *val) 190 { 191 int ret; 192 u32 tmp, value, status; 193 194 ret = hwspin_lock_timeout_raw(data->hwlock, SC27XX_ADC_HWLOCK_TIMEOUT); 195 if (ret) { 196 dev_err(data->dev, "timeout to get the hwspinlock\n"); 197 return ret; 198 } 199 200 ret = regmap_update_bits(data->regmap, data->base + SC27XX_ADC_CTL, 201 SC27XX_ADC_EN, SC27XX_ADC_EN); 202 if (ret) 203 goto unlock_adc; 204 205 ret = regmap_update_bits(data->regmap, data->base + SC27XX_ADC_INT_CLR, 206 SC27XX_ADC_IRQ_CLR, SC27XX_ADC_IRQ_CLR); 207 if (ret) 208 goto disable_adc; 209 210 /* Configure the channel id and scale */ 211 tmp = (scale << SC27XX_ADC_SCALE_SHIFT) & SC27XX_ADC_SCALE_MASK; 212 tmp |= channel & SC27XX_ADC_CHN_ID_MASK; 213 ret = regmap_update_bits(data->regmap, data->base + SC27XX_ADC_CH_CFG, 214 SC27XX_ADC_CHN_ID_MASK | SC27XX_ADC_SCALE_MASK, 215 tmp); 216 if (ret) 217 goto disable_adc; 218 219 /* Select 12bit conversion mode, and only sample 1 time */ 220 tmp = SC27XX_ADC_12BIT_MODE; 221 tmp |= (0 << SC27XX_ADC_RUN_NUM_SHIFT) & SC27XX_ADC_RUN_NUM_MASK; 222 ret = regmap_update_bits(data->regmap, data->base + SC27XX_ADC_CTL, 223 SC27XX_ADC_RUN_NUM_MASK | SC27XX_ADC_12BIT_MODE, 224 tmp); 225 if (ret) 226 goto disable_adc; 227 228 ret = regmap_update_bits(data->regmap, data->base + SC27XX_ADC_CTL, 229 SC27XX_ADC_CHN_RUN, SC27XX_ADC_CHN_RUN); 230 if (ret) 231 goto disable_adc; 232 233 ret = regmap_read_poll_timeout(data->regmap, 234 data->base + SC27XX_ADC_INT_RAW, 235 status, (status & SC27XX_ADC_IRQ_RAW), 236 SC27XX_ADC_POLL_RAW_STATUS, 237 SC27XX_ADC_RDY_TIMEOUT); 238 if (ret) { 239 dev_err(data->dev, "read adc timeout, status = 0x%x\n", status); 240 goto disable_adc; 241 } 242 243 ret = regmap_read(data->regmap, data->base + SC27XX_ADC_DATA, &value); 244 if (ret) 245 goto disable_adc; 246 247 value &= SC27XX_ADC_DATA_MASK; 248 249 disable_adc: 250 regmap_update_bits(data->regmap, data->base + SC27XX_ADC_CTL, 251 SC27XX_ADC_EN, 0); 252 unlock_adc: 253 hwspin_unlock_raw(data->hwlock); 254 255 if (!ret) 256 *val = value; 257 258 return ret; 259 } 260 261 static void sc27xx_adc_volt_ratio(struct sc27xx_adc_data *data, 262 int channel, int scale, 263 u32 *div_numerator, u32 *div_denominator) 264 { 265 u32 ratio = sc27xx_adc_get_ratio(channel, scale); 266 267 *div_numerator = ratio >> SC27XX_RATIO_NUMERATOR_OFFSET; 268 *div_denominator = ratio & SC27XX_RATIO_DENOMINATOR_MASK; 269 } 270 271 static int sc27xx_adc_to_volt(struct sc27xx_adc_linear_graph *graph, 272 int raw_adc) 273 { 274 int tmp; 275 276 tmp = (graph->volt0 - graph->volt1) * (raw_adc - graph->adc1); 277 tmp /= (graph->adc0 - graph->adc1); 278 tmp += graph->volt1; 279 280 return tmp < 0 ? 0 : tmp; 281 } 282 283 static int sc27xx_adc_convert_volt(struct sc27xx_adc_data *data, int channel, 284 int scale, int raw_adc) 285 { 286 u32 numerator, denominator; 287 u32 volt; 288 289 /* 290 * Convert ADC values to voltage values according to the linear graph, 291 * and channel 5 and channel 1 has been calibrated, so we can just 292 * return the voltage values calculated by the linear graph. But other 293 * channels need be calculated to the real voltage values with the 294 * voltage ratio. 295 */ 296 switch (channel) { 297 case 5: 298 return sc27xx_adc_to_volt(&big_scale_graph, raw_adc); 299 300 case 1: 301 return sc27xx_adc_to_volt(&small_scale_graph, raw_adc); 302 303 default: 304 volt = sc27xx_adc_to_volt(&small_scale_graph, raw_adc); 305 break; 306 } 307 308 sc27xx_adc_volt_ratio(data, channel, scale, &numerator, &denominator); 309 310 return (volt * denominator + numerator / 2) / numerator; 311 } 312 313 static int sc27xx_adc_read_processed(struct sc27xx_adc_data *data, 314 int channel, int scale, int *val) 315 { 316 int ret, raw_adc; 317 318 ret = sc27xx_adc_read(data, channel, scale, &raw_adc); 319 if (ret) 320 return ret; 321 322 *val = sc27xx_adc_convert_volt(data, channel, scale, raw_adc); 323 return 0; 324 } 325 326 static int sc27xx_adc_read_raw(struct iio_dev *indio_dev, 327 struct iio_chan_spec const *chan, 328 int *val, int *val2, long mask) 329 { 330 struct sc27xx_adc_data *data = iio_priv(indio_dev); 331 int scale = data->channel_scale[chan->channel]; 332 int ret, tmp; 333 334 switch (mask) { 335 case IIO_CHAN_INFO_RAW: 336 mutex_lock(&indio_dev->mlock); 337 ret = sc27xx_adc_read(data, chan->channel, scale, &tmp); 338 mutex_unlock(&indio_dev->mlock); 339 340 if (ret) 341 return ret; 342 343 *val = tmp; 344 return IIO_VAL_INT; 345 346 case IIO_CHAN_INFO_PROCESSED: 347 mutex_lock(&indio_dev->mlock); 348 ret = sc27xx_adc_read_processed(data, chan->channel, scale, 349 &tmp); 350 mutex_unlock(&indio_dev->mlock); 351 352 if (ret) 353 return ret; 354 355 *val = tmp; 356 return IIO_VAL_INT; 357 358 case IIO_CHAN_INFO_SCALE: 359 *val = scale; 360 return IIO_VAL_INT; 361 362 default: 363 return -EINVAL; 364 } 365 } 366 367 static int sc27xx_adc_write_raw(struct iio_dev *indio_dev, 368 struct iio_chan_spec const *chan, 369 int val, int val2, long mask) 370 { 371 struct sc27xx_adc_data *data = iio_priv(indio_dev); 372 373 switch (mask) { 374 case IIO_CHAN_INFO_SCALE: 375 data->channel_scale[chan->channel] = val; 376 return IIO_VAL_INT; 377 378 default: 379 return -EINVAL; 380 } 381 } 382 383 static const struct iio_info sc27xx_info = { 384 .read_raw = &sc27xx_adc_read_raw, 385 .write_raw = &sc27xx_adc_write_raw, 386 }; 387 388 #define SC27XX_ADC_CHANNEL(index, mask) { \ 389 .type = IIO_VOLTAGE, \ 390 .channel = index, \ 391 .info_mask_separate = mask | BIT(IIO_CHAN_INFO_SCALE), \ 392 .datasheet_name = "CH##index", \ 393 .indexed = 1, \ 394 } 395 396 static const struct iio_chan_spec sc27xx_channels[] = { 397 SC27XX_ADC_CHANNEL(0, BIT(IIO_CHAN_INFO_PROCESSED)), 398 SC27XX_ADC_CHANNEL(1, BIT(IIO_CHAN_INFO_PROCESSED)), 399 SC27XX_ADC_CHANNEL(2, BIT(IIO_CHAN_INFO_PROCESSED)), 400 SC27XX_ADC_CHANNEL(3, BIT(IIO_CHAN_INFO_PROCESSED)), 401 SC27XX_ADC_CHANNEL(4, BIT(IIO_CHAN_INFO_PROCESSED)), 402 SC27XX_ADC_CHANNEL(5, BIT(IIO_CHAN_INFO_PROCESSED)), 403 SC27XX_ADC_CHANNEL(6, BIT(IIO_CHAN_INFO_PROCESSED)), 404 SC27XX_ADC_CHANNEL(7, BIT(IIO_CHAN_INFO_PROCESSED)), 405 SC27XX_ADC_CHANNEL(8, BIT(IIO_CHAN_INFO_PROCESSED)), 406 SC27XX_ADC_CHANNEL(9, BIT(IIO_CHAN_INFO_PROCESSED)), 407 SC27XX_ADC_CHANNEL(10, BIT(IIO_CHAN_INFO_PROCESSED)), 408 SC27XX_ADC_CHANNEL(11, BIT(IIO_CHAN_INFO_PROCESSED)), 409 SC27XX_ADC_CHANNEL(12, BIT(IIO_CHAN_INFO_PROCESSED)), 410 SC27XX_ADC_CHANNEL(13, BIT(IIO_CHAN_INFO_PROCESSED)), 411 SC27XX_ADC_CHANNEL(14, BIT(IIO_CHAN_INFO_PROCESSED)), 412 SC27XX_ADC_CHANNEL(15, BIT(IIO_CHAN_INFO_PROCESSED)), 413 SC27XX_ADC_CHANNEL(16, BIT(IIO_CHAN_INFO_PROCESSED)), 414 SC27XX_ADC_CHANNEL(17, BIT(IIO_CHAN_INFO_PROCESSED)), 415 SC27XX_ADC_CHANNEL(18, BIT(IIO_CHAN_INFO_PROCESSED)), 416 SC27XX_ADC_CHANNEL(19, BIT(IIO_CHAN_INFO_PROCESSED)), 417 SC27XX_ADC_CHANNEL(20, BIT(IIO_CHAN_INFO_RAW)), 418 SC27XX_ADC_CHANNEL(21, BIT(IIO_CHAN_INFO_PROCESSED)), 419 SC27XX_ADC_CHANNEL(22, BIT(IIO_CHAN_INFO_PROCESSED)), 420 SC27XX_ADC_CHANNEL(23, BIT(IIO_CHAN_INFO_PROCESSED)), 421 SC27XX_ADC_CHANNEL(24, BIT(IIO_CHAN_INFO_PROCESSED)), 422 SC27XX_ADC_CHANNEL(25, BIT(IIO_CHAN_INFO_PROCESSED)), 423 SC27XX_ADC_CHANNEL(26, BIT(IIO_CHAN_INFO_PROCESSED)), 424 SC27XX_ADC_CHANNEL(27, BIT(IIO_CHAN_INFO_PROCESSED)), 425 SC27XX_ADC_CHANNEL(28, BIT(IIO_CHAN_INFO_PROCESSED)), 426 SC27XX_ADC_CHANNEL(29, BIT(IIO_CHAN_INFO_PROCESSED)), 427 SC27XX_ADC_CHANNEL(30, BIT(IIO_CHAN_INFO_PROCESSED)), 428 SC27XX_ADC_CHANNEL(31, BIT(IIO_CHAN_INFO_PROCESSED)), 429 }; 430 431 static int sc27xx_adc_enable(struct sc27xx_adc_data *data) 432 { 433 int ret; 434 435 ret = regmap_update_bits(data->regmap, SC27XX_MODULE_EN, 436 SC27XX_MODULE_ADC_EN, SC27XX_MODULE_ADC_EN); 437 if (ret) 438 return ret; 439 440 /* Enable ADC work clock and controller clock */ 441 ret = regmap_update_bits(data->regmap, SC27XX_ARM_CLK_EN, 442 SC27XX_CLK_ADC_EN | SC27XX_CLK_ADC_CLK_EN, 443 SC27XX_CLK_ADC_EN | SC27XX_CLK_ADC_CLK_EN); 444 if (ret) 445 goto disable_adc; 446 447 /* ADC channel scales' calibration from nvmem device */ 448 ret = sc27xx_adc_scale_calibration(data, true); 449 if (ret) 450 goto disable_clk; 451 452 ret = sc27xx_adc_scale_calibration(data, false); 453 if (ret) 454 goto disable_clk; 455 456 return 0; 457 458 disable_clk: 459 regmap_update_bits(data->regmap, SC27XX_ARM_CLK_EN, 460 SC27XX_CLK_ADC_EN | SC27XX_CLK_ADC_CLK_EN, 0); 461 disable_adc: 462 regmap_update_bits(data->regmap, SC27XX_MODULE_EN, 463 SC27XX_MODULE_ADC_EN, 0); 464 465 return ret; 466 } 467 468 static void sc27xx_adc_disable(void *_data) 469 { 470 struct sc27xx_adc_data *data = _data; 471 472 /* Disable ADC work clock and controller clock */ 473 regmap_update_bits(data->regmap, SC27XX_ARM_CLK_EN, 474 SC27XX_CLK_ADC_EN | SC27XX_CLK_ADC_CLK_EN, 0); 475 476 regmap_update_bits(data->regmap, SC27XX_MODULE_EN, 477 SC27XX_MODULE_ADC_EN, 0); 478 } 479 480 static int sc27xx_adc_probe(struct platform_device *pdev) 481 { 482 struct device *dev = &pdev->dev; 483 struct device_node *np = dev->of_node; 484 struct sc27xx_adc_data *sc27xx_data; 485 struct iio_dev *indio_dev; 486 int ret; 487 488 indio_dev = devm_iio_device_alloc(dev, sizeof(*sc27xx_data)); 489 if (!indio_dev) 490 return -ENOMEM; 491 492 sc27xx_data = iio_priv(indio_dev); 493 494 sc27xx_data->regmap = dev_get_regmap(dev->parent, NULL); 495 if (!sc27xx_data->regmap) { 496 dev_err(dev, "failed to get ADC regmap\n"); 497 return -ENODEV; 498 } 499 500 ret = of_property_read_u32(np, "reg", &sc27xx_data->base); 501 if (ret) { 502 dev_err(dev, "failed to get ADC base address\n"); 503 return ret; 504 } 505 506 sc27xx_data->irq = platform_get_irq(pdev, 0); 507 if (sc27xx_data->irq < 0) 508 return sc27xx_data->irq; 509 510 ret = of_hwspin_lock_get_id(np, 0); 511 if (ret < 0) { 512 dev_err(dev, "failed to get hwspinlock id\n"); 513 return ret; 514 } 515 516 sc27xx_data->hwlock = devm_hwspin_lock_request_specific(dev, ret); 517 if (!sc27xx_data->hwlock) { 518 dev_err(dev, "failed to request hwspinlock\n"); 519 return -ENXIO; 520 } 521 522 sc27xx_data->dev = dev; 523 524 ret = sc27xx_adc_enable(sc27xx_data); 525 if (ret) { 526 dev_err(dev, "failed to enable ADC module\n"); 527 return ret; 528 } 529 530 ret = devm_add_action_or_reset(dev, sc27xx_adc_disable, sc27xx_data); 531 if (ret) { 532 dev_err(dev, "failed to add ADC disable action\n"); 533 return ret; 534 } 535 536 indio_dev->dev.parent = dev; 537 indio_dev->name = dev_name(dev); 538 indio_dev->modes = INDIO_DIRECT_MODE; 539 indio_dev->info = &sc27xx_info; 540 indio_dev->channels = sc27xx_channels; 541 indio_dev->num_channels = ARRAY_SIZE(sc27xx_channels); 542 ret = devm_iio_device_register(dev, indio_dev); 543 if (ret) 544 dev_err(dev, "could not register iio (ADC)"); 545 546 return ret; 547 } 548 549 static const struct of_device_id sc27xx_adc_of_match[] = { 550 { .compatible = "sprd,sc2731-adc", }, 551 { } 552 }; 553 554 static struct platform_driver sc27xx_adc_driver = { 555 .probe = sc27xx_adc_probe, 556 .driver = { 557 .name = "sc27xx-adc", 558 .of_match_table = sc27xx_adc_of_match, 559 }, 560 }; 561 562 module_platform_driver(sc27xx_adc_driver); 563 564 MODULE_AUTHOR("Freeman Liu <freeman.liu@spreadtrum.com>"); 565 MODULE_DESCRIPTION("Spreadtrum SC27XX ADC Driver"); 566 MODULE_LICENSE("GPL v2"); 567