1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Driver for the Yamaha YAS magnetic sensors, often used in Samsung 4 * mobile phones. While all are not yet handled because of lacking 5 * hardware, expand this driver to handle the different variants: 6 * 7 * YAS530 MS-3E (2011 Samsung Galaxy S Advance) 8 * YAS532 MS-3R (2011 Samsung Galaxy S4) 9 * YAS533 MS-3F (Vivo 1633, 1707, V3, Y21L) 10 * (YAS534 is a magnetic switch, not handled) 11 * YAS535 MS-6C 12 * YAS536 MS-3W 13 * YAS537 MS-3T (2015 Samsung Galaxy S6, Note 5, Xiaomi) 14 * YAS539 MS-3S (2018 Samsung Galaxy A7 SM-A750FN) 15 * 16 * Code functions found in the MPU3050 YAS530 and YAS532 drivers 17 * named "inv_compass" in the Tegra Android kernel tree. 18 * Copyright (C) 2012 InvenSense Corporation 19 * 20 * Author: Linus Walleij <linus.walleij@linaro.org> 21 */ 22 #include <linux/bitfield.h> 23 #include <linux/bitops.h> 24 #include <linux/delay.h> 25 #include <linux/err.h> 26 #include <linux/gpio/consumer.h> 27 #include <linux/i2c.h> 28 #include <linux/module.h> 29 #include <linux/mod_devicetable.h> 30 #include <linux/mutex.h> 31 #include <linux/pm_runtime.h> 32 #include <linux/regmap.h> 33 #include <linux/regulator/consumer.h> 34 #include <linux/random.h> 35 36 #include <linux/iio/buffer.h> 37 #include <linux/iio/iio.h> 38 #include <linux/iio/trigger_consumer.h> 39 #include <linux/iio/triggered_buffer.h> 40 41 #include <asm/unaligned.h> 42 43 /* This register map covers YAS530 and YAS532 but differs in YAS 537 and YAS539 */ 44 #define YAS5XX_DEVICE_ID 0x80 45 #define YAS5XX_ACTUATE_INIT_COIL 0x81 46 #define YAS5XX_MEASURE 0x82 47 #define YAS5XX_CONFIG 0x83 48 #define YAS5XX_MEASURE_INTERVAL 0x84 49 #define YAS5XX_OFFSET_X 0x85 /* [-31 .. 31] */ 50 #define YAS5XX_OFFSET_Y1 0x86 /* [-31 .. 31] */ 51 #define YAS5XX_OFFSET_Y2 0x87 /* [-31 .. 31] */ 52 #define YAS5XX_TEST1 0x88 53 #define YAS5XX_TEST2 0x89 54 #define YAS5XX_CAL 0x90 55 #define YAS5XX_MEASURE_DATA 0xB0 56 57 /* Bits in the YAS5xx config register */ 58 #define YAS5XX_CONFIG_INTON BIT(0) /* Interrupt on? */ 59 #define YAS5XX_CONFIG_INTHACT BIT(1) /* Interrupt active high? */ 60 #define YAS5XX_CONFIG_CCK_MASK GENMASK(4, 2) 61 #define YAS5XX_CONFIG_CCK_SHIFT 2 62 63 /* Bits in the measure command register */ 64 #define YAS5XX_MEASURE_START BIT(0) 65 #define YAS5XX_MEASURE_LDTC BIT(1) 66 #define YAS5XX_MEASURE_FORS BIT(2) 67 #define YAS5XX_MEASURE_DLYMES BIT(4) 68 69 /* Bits in the measure data register */ 70 #define YAS5XX_MEASURE_DATA_BUSY BIT(7) 71 72 #define YAS530_DEVICE_ID 0x01 /* YAS530 (MS-3E) */ 73 #define YAS530_VERSION_A 0 /* YAS530 (MS-3E A) */ 74 #define YAS530_VERSION_B 1 /* YAS530B (MS-3E B) */ 75 #define YAS530_VERSION_A_COEF 380 76 #define YAS530_VERSION_B_COEF 550 77 #define YAS530_DATA_BITS 12 78 #define YAS530_DATA_CENTER BIT(YAS530_DATA_BITS - 1) 79 #define YAS530_DATA_OVERFLOW (BIT(YAS530_DATA_BITS) - 1) 80 81 #define YAS532_DEVICE_ID 0x02 /* YAS532/YAS533 (MS-3R/F) */ 82 #define YAS532_VERSION_AB 0 /* YAS532/533 AB (MS-3R/F AB) */ 83 #define YAS532_VERSION_AC 1 /* YAS532/533 AC (MS-3R/F AC) */ 84 #define YAS532_VERSION_AB_COEF 1800 85 #define YAS532_VERSION_AC_COEF_X 850 86 #define YAS532_VERSION_AC_COEF_Y1 750 87 #define YAS532_VERSION_AC_COEF_Y2 750 88 #define YAS532_DATA_BITS 13 89 #define YAS532_DATA_CENTER BIT(YAS532_DATA_BITS - 1) 90 #define YAS532_DATA_OVERFLOW (BIT(YAS532_DATA_BITS) - 1) 91 #define YAS532_20DEGREES 390 /* Looks like Kelvin */ 92 93 /* These variant IDs are known from code dumps */ 94 #define YAS537_DEVICE_ID 0x07 /* YAS537 (MS-3T) */ 95 #define YAS539_DEVICE_ID 0x08 /* YAS539 (MS-3S) */ 96 97 /* Turn off device regulators etc after 5 seconds of inactivity */ 98 #define YAS5XX_AUTOSUSPEND_DELAY_MS 5000 99 100 struct yas5xx_calibration { 101 /* Linearization calibration x, y1, y2 */ 102 s32 r[3]; 103 u32 f[3]; 104 /* Temperature compensation calibration */ 105 s32 Cx, Cy1, Cy2; 106 /* Misc calibration coefficients */ 107 s32 a2, a3, a4, a5, a6, a7, a8, a9, k; 108 /* clock divider */ 109 u8 dck; 110 }; 111 112 /** 113 * struct yas5xx - state container for the YAS5xx driver 114 * @dev: parent device pointer 115 * @devid: device ID number 116 * @version: device version 117 * @name: device name 118 * @calibration: calibration settings from the OTP storage 119 * @hard_offsets: offsets for each axis measured with initcoil actuated 120 * @orientation: mounting matrix, flipped axis etc 121 * @map: regmap to access the YAX5xx registers over I2C 122 * @regs: the vdd and vddio power regulators 123 * @reset: optional GPIO line used for handling RESET 124 * @lock: locks the magnetometer for exclusive use during a measurement (which 125 * involves several register transactions so the regmap lock is not enough) 126 * so that measurements get serialized in a first-come-first serve manner 127 * @scan: naturally aligned measurements 128 */ 129 struct yas5xx { 130 struct device *dev; 131 unsigned int devid; 132 unsigned int version; 133 char name[16]; 134 struct yas5xx_calibration calibration; 135 u8 hard_offsets[3]; 136 struct iio_mount_matrix orientation; 137 struct regmap *map; 138 struct regulator_bulk_data regs[2]; 139 struct gpio_desc *reset; 140 struct mutex lock; 141 /* 142 * The scanout is 4 x 32 bits in CPU endianness. 143 * Ensure timestamp is naturally aligned 144 */ 145 struct { 146 s32 channels[4]; 147 s64 ts __aligned(8); 148 } scan; 149 }; 150 151 /* On YAS530 the x, y1 and y2 values are 12 bits */ 152 static u16 yas530_extract_axis(u8 *data) 153 { 154 u16 val; 155 156 /* 157 * These are the bits used in a 16bit word: 158 * 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 159 * x x x x x x x x x x x x 160 */ 161 val = get_unaligned_be16(&data[0]); 162 val = FIELD_GET(GENMASK(14, 3), val); 163 return val; 164 } 165 166 /* On YAS532 the x, y1 and y2 values are 13 bits */ 167 static u16 yas532_extract_axis(u8 *data) 168 { 169 u16 val; 170 171 /* 172 * These are the bits used in a 16bit word: 173 * 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 174 * x x x x x x x x x x x x x 175 */ 176 val = get_unaligned_be16(&data[0]); 177 val = FIELD_GET(GENMASK(14, 2), val); 178 return val; 179 } 180 181 /** 182 * yas5xx_measure() - Make a measure from the hardware 183 * @yas5xx: The device state 184 * @t: the raw temperature measurement 185 * @x: the raw x axis measurement 186 * @y1: the y1 axis measurement 187 * @y2: the y2 axis measurement 188 * @return: 0 on success or error code 189 */ 190 static int yas5xx_measure(struct yas5xx *yas5xx, u16 *t, u16 *x, u16 *y1, u16 *y2) 191 { 192 unsigned int busy; 193 u8 data[8]; 194 int ret; 195 u16 val; 196 197 mutex_lock(&yas5xx->lock); 198 ret = regmap_write(yas5xx->map, YAS5XX_MEASURE, YAS5XX_MEASURE_START); 199 if (ret < 0) 200 goto out_unlock; 201 202 /* 203 * Typical time to measure 1500 us, max 2000 us so wait min 500 us 204 * and at most 20000 us (one magnitude more than the datsheet max) 205 * before timeout. 206 */ 207 ret = regmap_read_poll_timeout(yas5xx->map, YAS5XX_MEASURE_DATA, busy, 208 !(busy & YAS5XX_MEASURE_DATA_BUSY), 209 500, 20000); 210 if (ret) { 211 dev_err(yas5xx->dev, "timeout waiting for measurement\n"); 212 goto out_unlock; 213 } 214 215 ret = regmap_bulk_read(yas5xx->map, YAS5XX_MEASURE_DATA, 216 data, sizeof(data)); 217 if (ret) 218 goto out_unlock; 219 220 mutex_unlock(&yas5xx->lock); 221 222 switch (yas5xx->devid) { 223 case YAS530_DEVICE_ID: 224 /* 225 * The t value is 9 bits in big endian format 226 * These are the bits used in a 16bit word: 227 * 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 228 * x x x x x x x x x 229 */ 230 val = get_unaligned_be16(&data[0]); 231 val = FIELD_GET(GENMASK(14, 6), val); 232 *t = val; 233 *x = yas530_extract_axis(&data[2]); 234 *y1 = yas530_extract_axis(&data[4]); 235 *y2 = yas530_extract_axis(&data[6]); 236 break; 237 case YAS532_DEVICE_ID: 238 /* 239 * The t value is 10 bits in big endian format 240 * These are the bits used in a 16bit word: 241 * 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 242 * x x x x x x x x x x 243 */ 244 val = get_unaligned_be16(&data[0]); 245 val = FIELD_GET(GENMASK(14, 5), val); 246 *t = val; 247 *x = yas532_extract_axis(&data[2]); 248 *y1 = yas532_extract_axis(&data[4]); 249 *y2 = yas532_extract_axis(&data[6]); 250 break; 251 default: 252 dev_err(yas5xx->dev, "unknown data format\n"); 253 ret = -EINVAL; 254 break; 255 } 256 257 return ret; 258 259 out_unlock: 260 mutex_unlock(&yas5xx->lock); 261 return ret; 262 } 263 264 static s32 yas5xx_linearize(struct yas5xx *yas5xx, u16 val, int axis) 265 { 266 struct yas5xx_calibration *c = &yas5xx->calibration; 267 static const s32 yas532ac_coef[] = { 268 YAS532_VERSION_AC_COEF_X, 269 YAS532_VERSION_AC_COEF_Y1, 270 YAS532_VERSION_AC_COEF_Y2, 271 }; 272 s32 coef; 273 274 /* Select coefficients */ 275 switch (yas5xx->devid) { 276 case YAS530_DEVICE_ID: 277 if (yas5xx->version == YAS530_VERSION_A) 278 coef = YAS530_VERSION_A_COEF; 279 else 280 coef = YAS530_VERSION_B_COEF; 281 break; 282 case YAS532_DEVICE_ID: 283 if (yas5xx->version == YAS532_VERSION_AB) 284 coef = YAS532_VERSION_AB_COEF; 285 else 286 /* Elaborate coefficients */ 287 coef = yas532ac_coef[axis]; 288 break; 289 default: 290 dev_err(yas5xx->dev, "unknown device type\n"); 291 return val; 292 } 293 /* 294 * Linearization formula: 295 * 296 * x' = x - (3721 + 50 * f) + (xoffset - r) * c 297 * 298 * Where f and r are calibration values, c is a per-device 299 * and sometimes per-axis coefficient. 300 */ 301 return val - (3721 + 50 * c->f[axis]) + 302 (yas5xx->hard_offsets[axis] - c->r[axis]) * coef; 303 } 304 305 /** 306 * yas5xx_get_measure() - Measure a sample of all axis and process 307 * @yas5xx: The device state 308 * @to: Temperature out 309 * @xo: X axis out 310 * @yo: Y axis out 311 * @zo: Z axis out 312 * @return: 0 on success or error code 313 * 314 * Returned values are in nanotesla according to some code. 315 */ 316 static int yas5xx_get_measure(struct yas5xx *yas5xx, s32 *to, s32 *xo, s32 *yo, s32 *zo) 317 { 318 struct yas5xx_calibration *c = &yas5xx->calibration; 319 u16 t, x, y1, y2; 320 /* These are "signed x, signed y1 etc */ 321 s32 sx, sy1, sy2, sy, sz; 322 int ret; 323 324 /* We first get raw data that needs to be translated to [x,y,z] */ 325 ret = yas5xx_measure(yas5xx, &t, &x, &y1, &y2); 326 if (ret) 327 return ret; 328 329 /* Do some linearization if available */ 330 sx = yas5xx_linearize(yas5xx, x, 0); 331 sy1 = yas5xx_linearize(yas5xx, y1, 1); 332 sy2 = yas5xx_linearize(yas5xx, y2, 2); 333 334 /* 335 * Temperature compensation for x, y1, y2 respectively: 336 * 337 * Cx * t 338 * x' = x - ------ 339 * 100 340 */ 341 sx = sx - (c->Cx * t) / 100; 342 sy1 = sy1 - (c->Cy1 * t) / 100; 343 sy2 = sy2 - (c->Cy2 * t) / 100; 344 345 /* 346 * Break y1 and y2 into y and z, y1 and y2 are apparently encoding 347 * y and z. 348 */ 349 sy = sy1 - sy2; 350 sz = -sy1 - sy2; 351 352 /* 353 * FIXME: convert to Celsius? Just guessing this is given 354 * as 1/10:s of degrees so multiply by 100 to get millicentigrades. 355 */ 356 *to = t * 100; 357 /* 358 * Calibrate [x,y,z] with some formulas like this: 359 * 360 * 100 * x + a_2 * y + a_3 * z 361 * x' = k * --------------------------- 362 * 10 363 * 364 * a_4 * x + a_5 * y + a_6 * z 365 * y' = k * --------------------------- 366 * 10 367 * 368 * a_7 * x + a_8 * y + a_9 * z 369 * z' = k * --------------------------- 370 * 10 371 */ 372 *xo = c->k * ((100 * sx + c->a2 * sy + c->a3 * sz) / 10); 373 *yo = c->k * ((c->a4 * sx + c->a5 * sy + c->a6 * sz) / 10); 374 *zo = c->k * ((c->a7 * sx + c->a8 * sy + c->a9 * sz) / 10); 375 376 return 0; 377 } 378 379 static int yas5xx_read_raw(struct iio_dev *indio_dev, 380 struct iio_chan_spec const *chan, 381 int *val, int *val2, 382 long mask) 383 { 384 struct yas5xx *yas5xx = iio_priv(indio_dev); 385 s32 t, x, y, z; 386 int ret; 387 388 switch (mask) { 389 case IIO_CHAN_INFO_RAW: 390 pm_runtime_get_sync(yas5xx->dev); 391 ret = yas5xx_get_measure(yas5xx, &t, &x, &y, &z); 392 pm_runtime_mark_last_busy(yas5xx->dev); 393 pm_runtime_put_autosuspend(yas5xx->dev); 394 if (ret) 395 return ret; 396 switch (chan->address) { 397 case 0: 398 *val = t; 399 break; 400 case 1: 401 *val = x; 402 break; 403 case 2: 404 *val = y; 405 break; 406 case 3: 407 *val = z; 408 break; 409 default: 410 dev_err(yas5xx->dev, "unknown channel\n"); 411 return -EINVAL; 412 } 413 return IIO_VAL_INT; 414 case IIO_CHAN_INFO_SCALE: 415 if (chan->address == 0) { 416 /* Temperature is unscaled */ 417 *val = 1; 418 return IIO_VAL_INT; 419 } 420 /* 421 * The axis values are in nanotesla according to the vendor 422 * drivers, but is clearly in microtesla according to 423 * experiments. Since 1 uT = 0.01 Gauss, we need to divide 424 * by 100000000 (10^8) to get to Gauss from the raw value. 425 */ 426 *val = 1; 427 *val2 = 100000000; 428 return IIO_VAL_FRACTIONAL; 429 default: 430 /* Unknown request */ 431 return -EINVAL; 432 } 433 } 434 435 static void yas5xx_fill_buffer(struct iio_dev *indio_dev) 436 { 437 struct yas5xx *yas5xx = iio_priv(indio_dev); 438 s32 t, x, y, z; 439 int ret; 440 441 pm_runtime_get_sync(yas5xx->dev); 442 ret = yas5xx_get_measure(yas5xx, &t, &x, &y, &z); 443 pm_runtime_mark_last_busy(yas5xx->dev); 444 pm_runtime_put_autosuspend(yas5xx->dev); 445 if (ret) { 446 dev_err(yas5xx->dev, "error refilling buffer\n"); 447 return; 448 } 449 yas5xx->scan.channels[0] = t; 450 yas5xx->scan.channels[1] = x; 451 yas5xx->scan.channels[2] = y; 452 yas5xx->scan.channels[3] = z; 453 iio_push_to_buffers_with_timestamp(indio_dev, &yas5xx->scan, 454 iio_get_time_ns(indio_dev)); 455 } 456 457 static irqreturn_t yas5xx_handle_trigger(int irq, void *p) 458 { 459 const struct iio_poll_func *pf = p; 460 struct iio_dev *indio_dev = pf->indio_dev; 461 462 yas5xx_fill_buffer(indio_dev); 463 iio_trigger_notify_done(indio_dev->trig); 464 465 return IRQ_HANDLED; 466 } 467 468 469 static const struct iio_mount_matrix * 470 yas5xx_get_mount_matrix(const struct iio_dev *indio_dev, 471 const struct iio_chan_spec *chan) 472 { 473 struct yas5xx *yas5xx = iio_priv(indio_dev); 474 475 return &yas5xx->orientation; 476 } 477 478 static const struct iio_chan_spec_ext_info yas5xx_ext_info[] = { 479 IIO_MOUNT_MATRIX(IIO_SHARED_BY_DIR, yas5xx_get_mount_matrix), 480 { } 481 }; 482 483 #define YAS5XX_AXIS_CHANNEL(axis, index) \ 484 { \ 485 .type = IIO_MAGN, \ 486 .modified = 1, \ 487 .channel2 = IIO_MOD_##axis, \ 488 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \ 489 BIT(IIO_CHAN_INFO_SCALE), \ 490 .ext_info = yas5xx_ext_info, \ 491 .address = index, \ 492 .scan_index = index, \ 493 .scan_type = { \ 494 .sign = 's', \ 495 .realbits = 32, \ 496 .storagebits = 32, \ 497 .endianness = IIO_CPU, \ 498 }, \ 499 } 500 501 static const struct iio_chan_spec yas5xx_channels[] = { 502 { 503 .type = IIO_TEMP, 504 .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED), 505 .address = 0, 506 .scan_index = 0, 507 .scan_type = { 508 .sign = 'u', 509 .realbits = 32, 510 .storagebits = 32, 511 .endianness = IIO_CPU, 512 }, 513 }, 514 YAS5XX_AXIS_CHANNEL(X, 1), 515 YAS5XX_AXIS_CHANNEL(Y, 2), 516 YAS5XX_AXIS_CHANNEL(Z, 3), 517 IIO_CHAN_SOFT_TIMESTAMP(4), 518 }; 519 520 static const unsigned long yas5xx_scan_masks[] = { GENMASK(3, 0), 0 }; 521 522 static const struct iio_info yas5xx_info = { 523 .read_raw = &yas5xx_read_raw, 524 }; 525 526 static bool yas5xx_volatile_reg(struct device *dev, unsigned int reg) 527 { 528 return reg == YAS5XX_ACTUATE_INIT_COIL || 529 reg == YAS5XX_MEASURE || 530 (reg >= YAS5XX_MEASURE_DATA && reg <= YAS5XX_MEASURE_DATA + 8); 531 } 532 533 /* TODO: enable regmap cache, using mark dirty and sync at runtime resume */ 534 static const struct regmap_config yas5xx_regmap_config = { 535 .reg_bits = 8, 536 .val_bits = 8, 537 .max_register = 0xff, 538 .volatile_reg = yas5xx_volatile_reg, 539 }; 540 541 /** 542 * yas53x_extract_calibration() - extracts the a2-a9 and k calibration 543 * @data: the bitfield to use 544 * @c: the calibration to populate 545 */ 546 static void yas53x_extract_calibration(u8 *data, struct yas5xx_calibration *c) 547 { 548 u64 val = get_unaligned_be64(data); 549 550 /* 551 * Bitfield layout for the axis calibration data, for factor 552 * a2 = 2 etc, k = k, c = clock divider 553 * 554 * n 7 6 5 4 3 2 1 0 555 * 0 [ 2 2 2 2 2 2 3 3 ] bits 63 .. 56 556 * 1 [ 3 3 4 4 4 4 4 4 ] bits 55 .. 48 557 * 2 [ 5 5 5 5 5 5 6 6 ] bits 47 .. 40 558 * 3 [ 6 6 6 6 7 7 7 7 ] bits 39 .. 32 559 * 4 [ 7 7 7 8 8 8 8 8 ] bits 31 .. 24 560 * 5 [ 8 9 9 9 9 9 9 9 ] bits 23 .. 16 561 * 6 [ 9 k k k k k c c ] bits 15 .. 8 562 * 7 [ c x x x x x x x ] bits 7 .. 0 563 */ 564 c->a2 = FIELD_GET(GENMASK_ULL(63, 58), val) - 32; 565 c->a3 = FIELD_GET(GENMASK_ULL(57, 54), val) - 8; 566 c->a4 = FIELD_GET(GENMASK_ULL(53, 48), val) - 32; 567 c->a5 = FIELD_GET(GENMASK_ULL(47, 42), val) + 38; 568 c->a6 = FIELD_GET(GENMASK_ULL(41, 36), val) - 32; 569 c->a7 = FIELD_GET(GENMASK_ULL(35, 29), val) - 64; 570 c->a8 = FIELD_GET(GENMASK_ULL(28, 23), val) - 32; 571 c->a9 = FIELD_GET(GENMASK_ULL(22, 15), val); 572 c->k = FIELD_GET(GENMASK_ULL(14, 10), val) + 10; 573 c->dck = FIELD_GET(GENMASK_ULL(9, 7), val); 574 } 575 576 static int yas530_get_calibration_data(struct yas5xx *yas5xx) 577 { 578 struct yas5xx_calibration *c = &yas5xx->calibration; 579 u8 data[16]; 580 u32 val; 581 int ret; 582 583 /* Dummy read, first read is ALWAYS wrong */ 584 ret = regmap_bulk_read(yas5xx->map, YAS5XX_CAL, data, sizeof(data)); 585 if (ret) 586 return ret; 587 588 /* Actual calibration readout */ 589 ret = regmap_bulk_read(yas5xx->map, YAS5XX_CAL, data, sizeof(data)); 590 if (ret) 591 return ret; 592 dev_dbg(yas5xx->dev, "calibration data: %*ph\n", 14, data); 593 594 add_device_randomness(data, sizeof(data)); 595 yas5xx->version = data[15] & GENMASK(1, 0); 596 597 /* Extract the calibration from the bitfield */ 598 c->Cx = data[0] * 6 - 768; 599 c->Cy1 = data[1] * 6 - 768; 600 c->Cy2 = data[2] * 6 - 768; 601 yas53x_extract_calibration(&data[3], c); 602 603 /* 604 * Extract linearization: 605 * Linearization layout in the 32 bits at byte 11: 606 * The r factors are 6 bit values where bit 5 is the sign 607 * 608 * n 7 6 5 4 3 2 1 0 609 * 0 [ xx xx xx r0 r0 r0 r0 r0 ] bits 31 .. 24 610 * 1 [ r0 f0 f0 r1 r1 r1 r1 r1 ] bits 23 .. 16 611 * 2 [ r1 f1 f1 r2 r2 r2 r2 r2 ] bits 15 .. 8 612 * 3 [ r2 f2 f2 xx xx xx xx xx ] bits 7 .. 0 613 */ 614 val = get_unaligned_be32(&data[11]); 615 c->f[0] = FIELD_GET(GENMASK(22, 21), val); 616 c->f[1] = FIELD_GET(GENMASK(14, 13), val); 617 c->f[2] = FIELD_GET(GENMASK(6, 5), val); 618 c->r[0] = sign_extend32(FIELD_GET(GENMASK(28, 23), val), 5); 619 c->r[1] = sign_extend32(FIELD_GET(GENMASK(20, 15), val), 5); 620 c->r[2] = sign_extend32(FIELD_GET(GENMASK(12, 7), val), 5); 621 return 0; 622 } 623 624 static int yas532_get_calibration_data(struct yas5xx *yas5xx) 625 { 626 struct yas5xx_calibration *c = &yas5xx->calibration; 627 u8 data[14]; 628 u32 val; 629 int ret; 630 631 /* Dummy read, first read is ALWAYS wrong */ 632 ret = regmap_bulk_read(yas5xx->map, YAS5XX_CAL, data, sizeof(data)); 633 if (ret) 634 return ret; 635 /* Actual calibration readout */ 636 ret = regmap_bulk_read(yas5xx->map, YAS5XX_CAL, data, sizeof(data)); 637 if (ret) 638 return ret; 639 dev_dbg(yas5xx->dev, "calibration data: %*ph\n", 14, data); 640 641 /* Sanity check, is this all zeroes? */ 642 if (memchr_inv(data, 0x00, 13) == NULL) { 643 if (!(data[13] & BIT(7))) 644 dev_warn(yas5xx->dev, "calibration is blank!\n"); 645 } 646 647 add_device_randomness(data, sizeof(data)); 648 /* Only one bit of version info reserved here as far as we know */ 649 yas5xx->version = data[13] & BIT(0); 650 651 /* Extract calibration from the bitfield */ 652 c->Cx = data[0] * 10 - 1280; 653 c->Cy1 = data[1] * 10 - 1280; 654 c->Cy2 = data[2] * 10 - 1280; 655 yas53x_extract_calibration(&data[3], c); 656 /* 657 * Extract linearization: 658 * Linearization layout in the 32 bits at byte 10: 659 * The r factors are 6 bit values where bit 5 is the sign 660 * 661 * n 7 6 5 4 3 2 1 0 662 * 0 [ xx r0 r0 r0 r0 r0 r0 f0 ] bits 31 .. 24 663 * 1 [ f0 r1 r1 r1 r1 r1 r1 f1 ] bits 23 .. 16 664 * 2 [ f1 r2 r2 r2 r2 r2 r2 f2 ] bits 15 .. 8 665 * 3 [ f2 xx xx xx xx xx xx xx ] bits 7 .. 0 666 */ 667 val = get_unaligned_be32(&data[10]); 668 c->f[0] = FIELD_GET(GENMASK(24, 23), val); 669 c->f[1] = FIELD_GET(GENMASK(16, 15), val); 670 c->f[2] = FIELD_GET(GENMASK(8, 7), val); 671 c->r[0] = sign_extend32(FIELD_GET(GENMASK(30, 25), val), 5); 672 c->r[1] = sign_extend32(FIELD_GET(GENMASK(22, 17), val), 5); 673 c->r[2] = sign_extend32(FIELD_GET(GENMASK(14, 7), val), 5); 674 675 return 0; 676 } 677 678 static void yas5xx_dump_calibration(struct yas5xx *yas5xx) 679 { 680 struct yas5xx_calibration *c = &yas5xx->calibration; 681 682 dev_dbg(yas5xx->dev, "f[] = [%d, %d, %d]\n", 683 c->f[0], c->f[1], c->f[2]); 684 dev_dbg(yas5xx->dev, "r[] = [%d, %d, %d]\n", 685 c->r[0], c->r[1], c->r[2]); 686 dev_dbg(yas5xx->dev, "Cx = %d\n", c->Cx); 687 dev_dbg(yas5xx->dev, "Cy1 = %d\n", c->Cy1); 688 dev_dbg(yas5xx->dev, "Cy2 = %d\n", c->Cy2); 689 dev_dbg(yas5xx->dev, "a2 = %d\n", c->a2); 690 dev_dbg(yas5xx->dev, "a3 = %d\n", c->a3); 691 dev_dbg(yas5xx->dev, "a4 = %d\n", c->a4); 692 dev_dbg(yas5xx->dev, "a5 = %d\n", c->a5); 693 dev_dbg(yas5xx->dev, "a6 = %d\n", c->a6); 694 dev_dbg(yas5xx->dev, "a7 = %d\n", c->a7); 695 dev_dbg(yas5xx->dev, "a8 = %d\n", c->a8); 696 dev_dbg(yas5xx->dev, "a9 = %d\n", c->a9); 697 dev_dbg(yas5xx->dev, "k = %d\n", c->k); 698 dev_dbg(yas5xx->dev, "dck = %d\n", c->dck); 699 } 700 701 static int yas5xx_set_offsets(struct yas5xx *yas5xx, s8 ox, s8 oy1, s8 oy2) 702 { 703 int ret; 704 705 ret = regmap_write(yas5xx->map, YAS5XX_OFFSET_X, ox); 706 if (ret) 707 return ret; 708 ret = regmap_write(yas5xx->map, YAS5XX_OFFSET_Y1, oy1); 709 if (ret) 710 return ret; 711 return regmap_write(yas5xx->map, YAS5XX_OFFSET_Y2, oy2); 712 } 713 714 static s8 yas5xx_adjust_offset(s8 old, int bit, u16 center, u16 measure) 715 { 716 if (measure > center) 717 return old + BIT(bit); 718 if (measure < center) 719 return old - BIT(bit); 720 return old; 721 } 722 723 static int yas5xx_meaure_offsets(struct yas5xx *yas5xx) 724 { 725 int ret; 726 u16 center; 727 u16 t, x, y1, y2; 728 s8 ox, oy1, oy2; 729 int i; 730 731 /* Actuate the init coil and measure offsets */ 732 ret = regmap_write(yas5xx->map, YAS5XX_ACTUATE_INIT_COIL, 0); 733 if (ret) 734 return ret; 735 736 /* When the initcoil is active this should be around the center */ 737 switch (yas5xx->devid) { 738 case YAS530_DEVICE_ID: 739 center = YAS530_DATA_CENTER; 740 break; 741 case YAS532_DEVICE_ID: 742 center = YAS532_DATA_CENTER; 743 break; 744 default: 745 dev_err(yas5xx->dev, "unknown device type\n"); 746 return -EINVAL; 747 } 748 749 /* 750 * We set offsets in the interval +-31 by iterating 751 * +-16, +-8, +-4, +-2, +-1 adjusting the offsets each 752 * time, then writing the final offsets into the 753 * registers. 754 * 755 * NOTE: these offsets are NOT in the same unit or magnitude 756 * as the values for [x, y1, y2]. The value is +/-31 757 * but the effect on the raw values is much larger. 758 * The effect of the offset is to bring the measure 759 * rougly to the center. 760 */ 761 ox = 0; 762 oy1 = 0; 763 oy2 = 0; 764 765 for (i = 4; i >= 0; i--) { 766 ret = yas5xx_set_offsets(yas5xx, ox, oy1, oy2); 767 if (ret) 768 return ret; 769 770 ret = yas5xx_measure(yas5xx, &t, &x, &y1, &y2); 771 if (ret) 772 return ret; 773 dev_dbg(yas5xx->dev, "measurement %d: x=%d, y1=%d, y2=%d\n", 774 5-i, x, y1, y2); 775 776 ox = yas5xx_adjust_offset(ox, i, center, x); 777 oy1 = yas5xx_adjust_offset(oy1, i, center, y1); 778 oy2 = yas5xx_adjust_offset(oy2, i, center, y2); 779 } 780 781 /* Needed for calibration algorithm */ 782 yas5xx->hard_offsets[0] = ox; 783 yas5xx->hard_offsets[1] = oy1; 784 yas5xx->hard_offsets[2] = oy2; 785 ret = yas5xx_set_offsets(yas5xx, ox, oy1, oy2); 786 if (ret) 787 return ret; 788 789 dev_info(yas5xx->dev, "discovered hard offsets: x=%d, y1=%d, y2=%d\n", 790 ox, oy1, oy2); 791 return 0; 792 } 793 794 static int yas5xx_power_on(struct yas5xx *yas5xx) 795 { 796 unsigned int val; 797 int ret; 798 799 /* Zero the test registers */ 800 ret = regmap_write(yas5xx->map, YAS5XX_TEST1, 0); 801 if (ret) 802 return ret; 803 ret = regmap_write(yas5xx->map, YAS5XX_TEST2, 0); 804 if (ret) 805 return ret; 806 807 /* Set up for no interrupts, calibrated clock divider */ 808 val = FIELD_PREP(YAS5XX_CONFIG_CCK_MASK, yas5xx->calibration.dck); 809 ret = regmap_write(yas5xx->map, YAS5XX_CONFIG, val); 810 if (ret) 811 return ret; 812 813 /* Measure interval 0 (back-to-back?) */ 814 return regmap_write(yas5xx->map, YAS5XX_MEASURE_INTERVAL, 0); 815 } 816 817 static int yas5xx_probe(struct i2c_client *i2c, 818 const struct i2c_device_id *id) 819 { 820 struct iio_dev *indio_dev; 821 struct device *dev = &i2c->dev; 822 struct yas5xx *yas5xx; 823 int ret; 824 825 indio_dev = devm_iio_device_alloc(dev, sizeof(*yas5xx)); 826 if (!indio_dev) 827 return -ENOMEM; 828 829 yas5xx = iio_priv(indio_dev); 830 i2c_set_clientdata(i2c, indio_dev); 831 yas5xx->dev = dev; 832 mutex_init(&yas5xx->lock); 833 834 ret = iio_read_mount_matrix(dev, &yas5xx->orientation); 835 if (ret) 836 return ret; 837 838 yas5xx->regs[0].supply = "vdd"; 839 yas5xx->regs[1].supply = "iovdd"; 840 ret = devm_regulator_bulk_get(dev, ARRAY_SIZE(yas5xx->regs), 841 yas5xx->regs); 842 if (ret) 843 return dev_err_probe(dev, ret, "cannot get regulators\n"); 844 845 ret = regulator_bulk_enable(ARRAY_SIZE(yas5xx->regs), yas5xx->regs); 846 if (ret) { 847 dev_err(dev, "cannot enable regulators\n"); 848 return ret; 849 } 850 851 /* See comment in runtime resume callback */ 852 usleep_range(31000, 40000); 853 854 /* This will take the device out of reset if need be */ 855 yas5xx->reset = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_LOW); 856 if (IS_ERR(yas5xx->reset)) { 857 ret = dev_err_probe(dev, PTR_ERR(yas5xx->reset), 858 "failed to get reset line\n"); 859 goto reg_off; 860 } 861 862 yas5xx->map = devm_regmap_init_i2c(i2c, &yas5xx_regmap_config); 863 if (IS_ERR(yas5xx->map)) { 864 dev_err(dev, "failed to allocate register map\n"); 865 ret = PTR_ERR(yas5xx->map); 866 goto assert_reset; 867 } 868 869 ret = regmap_read(yas5xx->map, YAS5XX_DEVICE_ID, &yas5xx->devid); 870 if (ret) 871 goto assert_reset; 872 873 switch (yas5xx->devid) { 874 case YAS530_DEVICE_ID: 875 ret = yas530_get_calibration_data(yas5xx); 876 if (ret) 877 goto assert_reset; 878 dev_info(dev, "detected YAS530 MS-3E %s", 879 yas5xx->version ? "B" : "A"); 880 strncpy(yas5xx->name, "yas530", sizeof(yas5xx->name)); 881 break; 882 case YAS532_DEVICE_ID: 883 ret = yas532_get_calibration_data(yas5xx); 884 if (ret) 885 goto assert_reset; 886 dev_info(dev, "detected YAS532/YAS533 MS-3R/F %s", 887 yas5xx->version ? "AC" : "AB"); 888 strncpy(yas5xx->name, "yas532", sizeof(yas5xx->name)); 889 break; 890 default: 891 ret = -ENODEV; 892 dev_err(dev, "unhandled device ID %02x\n", yas5xx->devid); 893 goto assert_reset; 894 } 895 896 yas5xx_dump_calibration(yas5xx); 897 ret = yas5xx_power_on(yas5xx); 898 if (ret) 899 goto assert_reset; 900 ret = yas5xx_meaure_offsets(yas5xx); 901 if (ret) 902 goto assert_reset; 903 904 indio_dev->info = &yas5xx_info; 905 indio_dev->available_scan_masks = yas5xx_scan_masks; 906 indio_dev->modes = INDIO_DIRECT_MODE; 907 indio_dev->name = yas5xx->name; 908 indio_dev->channels = yas5xx_channels; 909 indio_dev->num_channels = ARRAY_SIZE(yas5xx_channels); 910 911 ret = iio_triggered_buffer_setup(indio_dev, NULL, 912 yas5xx_handle_trigger, 913 NULL); 914 if (ret) { 915 dev_err(dev, "triggered buffer setup failed\n"); 916 goto assert_reset; 917 } 918 919 ret = iio_device_register(indio_dev); 920 if (ret) { 921 dev_err(dev, "device register failed\n"); 922 goto cleanup_buffer; 923 } 924 925 /* Take runtime PM online */ 926 pm_runtime_get_noresume(dev); 927 pm_runtime_set_active(dev); 928 pm_runtime_enable(dev); 929 930 pm_runtime_set_autosuspend_delay(dev, YAS5XX_AUTOSUSPEND_DELAY_MS); 931 pm_runtime_use_autosuspend(dev); 932 pm_runtime_put(dev); 933 934 return 0; 935 936 cleanup_buffer: 937 iio_triggered_buffer_cleanup(indio_dev); 938 assert_reset: 939 gpiod_set_value_cansleep(yas5xx->reset, 1); 940 reg_off: 941 regulator_bulk_disable(ARRAY_SIZE(yas5xx->regs), yas5xx->regs); 942 943 return ret; 944 } 945 946 static int yas5xx_remove(struct i2c_client *i2c) 947 { 948 struct iio_dev *indio_dev = i2c_get_clientdata(i2c); 949 struct yas5xx *yas5xx = iio_priv(indio_dev); 950 struct device *dev = &i2c->dev; 951 952 iio_device_unregister(indio_dev); 953 iio_triggered_buffer_cleanup(indio_dev); 954 /* 955 * Now we can't get any more reads from the device, which would 956 * also call pm_runtime* functions and race with our disable 957 * code. Disable PM runtime in orderly fashion and power down. 958 */ 959 pm_runtime_get_sync(dev); 960 pm_runtime_put_noidle(dev); 961 pm_runtime_disable(dev); 962 gpiod_set_value_cansleep(yas5xx->reset, 1); 963 regulator_bulk_disable(ARRAY_SIZE(yas5xx->regs), yas5xx->regs); 964 965 return 0; 966 } 967 968 static int yas5xx_runtime_suspend(struct device *dev) 969 { 970 struct iio_dev *indio_dev = dev_get_drvdata(dev); 971 struct yas5xx *yas5xx = iio_priv(indio_dev); 972 973 gpiod_set_value_cansleep(yas5xx->reset, 1); 974 regulator_bulk_disable(ARRAY_SIZE(yas5xx->regs), yas5xx->regs); 975 976 return 0; 977 } 978 979 static int yas5xx_runtime_resume(struct device *dev) 980 { 981 struct iio_dev *indio_dev = dev_get_drvdata(dev); 982 struct yas5xx *yas5xx = iio_priv(indio_dev); 983 int ret; 984 985 ret = regulator_bulk_enable(ARRAY_SIZE(yas5xx->regs), yas5xx->regs); 986 if (ret) { 987 dev_err(dev, "cannot enable regulators\n"); 988 return ret; 989 } 990 991 /* 992 * The YAS530 datasheet says TVSKW is up to 30 ms, after that 1 ms 993 * for all voltages to settle. The YAS532 is 10ms then 4ms for the 994 * I2C to come online. Let's keep it safe and put this at 31ms. 995 */ 996 usleep_range(31000, 40000); 997 gpiod_set_value_cansleep(yas5xx->reset, 0); 998 999 ret = yas5xx_power_on(yas5xx); 1000 if (ret) { 1001 dev_err(dev, "cannot power on\n"); 1002 goto out_reset; 1003 } 1004 1005 return 0; 1006 1007 out_reset: 1008 gpiod_set_value_cansleep(yas5xx->reset, 1); 1009 regulator_bulk_disable(ARRAY_SIZE(yas5xx->regs), yas5xx->regs); 1010 1011 return ret; 1012 } 1013 1014 static DEFINE_RUNTIME_DEV_PM_OPS(yas5xx_dev_pm_ops, yas5xx_runtime_suspend, 1015 yas5xx_runtime_resume, NULL); 1016 1017 static const struct i2c_device_id yas5xx_id[] = { 1018 {"yas530", }, 1019 {"yas532", }, 1020 {"yas533", }, 1021 {} 1022 }; 1023 MODULE_DEVICE_TABLE(i2c, yas5xx_id); 1024 1025 static const struct of_device_id yas5xx_of_match[] = { 1026 { .compatible = "yamaha,yas530", }, 1027 { .compatible = "yamaha,yas532", }, 1028 { .compatible = "yamaha,yas533", }, 1029 {} 1030 }; 1031 MODULE_DEVICE_TABLE(of, yas5xx_of_match); 1032 1033 static struct i2c_driver yas5xx_driver = { 1034 .driver = { 1035 .name = "yas5xx", 1036 .of_match_table = yas5xx_of_match, 1037 .pm = pm_ptr(&yas5xx_dev_pm_ops), 1038 }, 1039 .probe = yas5xx_probe, 1040 .remove = yas5xx_remove, 1041 .id_table = yas5xx_id, 1042 }; 1043 module_i2c_driver(yas5xx_driver); 1044 1045 MODULE_DESCRIPTION("Yamaha YAS53x 3-axis magnetometer driver"); 1046 MODULE_AUTHOR("Linus Walleij"); 1047 MODULE_LICENSE("GPL v2"); 1048