1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * A sensor driver for the magnetometer AK8975. 4 * 5 * Magnetic compass sensor driver for monitoring magnetic flux information. 6 * 7 * Copyright (c) 2010, NVIDIA Corporation. 8 */ 9 10 #include <linux/module.h> 11 #include <linux/mod_devicetable.h> 12 #include <linux/kernel.h> 13 #include <linux/slab.h> 14 #include <linux/i2c.h> 15 #include <linux/interrupt.h> 16 #include <linux/err.h> 17 #include <linux/mutex.h> 18 #include <linux/delay.h> 19 #include <linux/bitops.h> 20 #include <linux/gpio/consumer.h> 21 #include <linux/regulator/consumer.h> 22 #include <linux/pm_runtime.h> 23 24 #include <linux/iio/iio.h> 25 #include <linux/iio/sysfs.h> 26 #include <linux/iio/buffer.h> 27 #include <linux/iio/trigger.h> 28 #include <linux/iio/trigger_consumer.h> 29 #include <linux/iio/triggered_buffer.h> 30 31 /* 32 * Register definitions, as well as various shifts and masks to get at the 33 * individual fields of the registers. 34 */ 35 #define AK8975_REG_WIA 0x00 36 #define AK8975_DEVICE_ID 0x48 37 38 #define AK8975_REG_INFO 0x01 39 40 #define AK8975_REG_ST1 0x02 41 #define AK8975_REG_ST1_DRDY_SHIFT 0 42 #define AK8975_REG_ST1_DRDY_MASK (1 << AK8975_REG_ST1_DRDY_SHIFT) 43 44 #define AK8975_REG_HXL 0x03 45 #define AK8975_REG_HXH 0x04 46 #define AK8975_REG_HYL 0x05 47 #define AK8975_REG_HYH 0x06 48 #define AK8975_REG_HZL 0x07 49 #define AK8975_REG_HZH 0x08 50 #define AK8975_REG_ST2 0x09 51 #define AK8975_REG_ST2_DERR_SHIFT 2 52 #define AK8975_REG_ST2_DERR_MASK (1 << AK8975_REG_ST2_DERR_SHIFT) 53 54 #define AK8975_REG_ST2_HOFL_SHIFT 3 55 #define AK8975_REG_ST2_HOFL_MASK (1 << AK8975_REG_ST2_HOFL_SHIFT) 56 57 #define AK8975_REG_CNTL 0x0A 58 #define AK8975_REG_CNTL_MODE_SHIFT 0 59 #define AK8975_REG_CNTL_MODE_MASK (0xF << AK8975_REG_CNTL_MODE_SHIFT) 60 #define AK8975_REG_CNTL_MODE_POWER_DOWN 0x00 61 #define AK8975_REG_CNTL_MODE_ONCE 0x01 62 #define AK8975_REG_CNTL_MODE_SELF_TEST 0x08 63 #define AK8975_REG_CNTL_MODE_FUSE_ROM 0x0F 64 65 #define AK8975_REG_RSVC 0x0B 66 #define AK8975_REG_ASTC 0x0C 67 #define AK8975_REG_TS1 0x0D 68 #define AK8975_REG_TS2 0x0E 69 #define AK8975_REG_I2CDIS 0x0F 70 #define AK8975_REG_ASAX 0x10 71 #define AK8975_REG_ASAY 0x11 72 #define AK8975_REG_ASAZ 0x12 73 74 #define AK8975_MAX_REGS AK8975_REG_ASAZ 75 76 /* 77 * AK09912 Register definitions 78 */ 79 #define AK09912_REG_WIA1 0x00 80 #define AK09912_REG_WIA2 0x01 81 #define AK09916_DEVICE_ID 0x09 82 #define AK09912_DEVICE_ID 0x04 83 #define AK09911_DEVICE_ID 0x05 84 85 #define AK09911_REG_INFO1 0x02 86 #define AK09911_REG_INFO2 0x03 87 88 #define AK09912_REG_ST1 0x10 89 90 #define AK09912_REG_ST1_DRDY_SHIFT 0 91 #define AK09912_REG_ST1_DRDY_MASK (1 << AK09912_REG_ST1_DRDY_SHIFT) 92 93 #define AK09912_REG_HXL 0x11 94 #define AK09912_REG_HXH 0x12 95 #define AK09912_REG_HYL 0x13 96 #define AK09912_REG_HYH 0x14 97 #define AK09912_REG_HZL 0x15 98 #define AK09912_REG_HZH 0x16 99 #define AK09912_REG_TMPS 0x17 100 101 #define AK09912_REG_ST2 0x18 102 #define AK09912_REG_ST2_HOFL_SHIFT 3 103 #define AK09912_REG_ST2_HOFL_MASK (1 << AK09912_REG_ST2_HOFL_SHIFT) 104 105 #define AK09912_REG_CNTL1 0x30 106 107 #define AK09912_REG_CNTL2 0x31 108 #define AK09912_REG_CNTL_MODE_POWER_DOWN 0x00 109 #define AK09912_REG_CNTL_MODE_ONCE 0x01 110 #define AK09912_REG_CNTL_MODE_SELF_TEST 0x10 111 #define AK09912_REG_CNTL_MODE_FUSE_ROM 0x1F 112 #define AK09912_REG_CNTL2_MODE_SHIFT 0 113 #define AK09912_REG_CNTL2_MODE_MASK (0x1F << AK09912_REG_CNTL2_MODE_SHIFT) 114 115 #define AK09912_REG_CNTL3 0x32 116 117 #define AK09912_REG_TS1 0x33 118 #define AK09912_REG_TS2 0x34 119 #define AK09912_REG_TS3 0x35 120 #define AK09912_REG_I2CDIS 0x36 121 #define AK09912_REG_TS4 0x37 122 123 #define AK09912_REG_ASAX 0x60 124 #define AK09912_REG_ASAY 0x61 125 #define AK09912_REG_ASAZ 0x62 126 127 #define AK09912_MAX_REGS AK09912_REG_ASAZ 128 129 /* 130 * Miscellaneous values. 131 */ 132 #define AK8975_MAX_CONVERSION_TIMEOUT 500 133 #define AK8975_CONVERSION_DONE_POLL_TIME 10 134 #define AK8975_DATA_READY_TIMEOUT ((100*HZ)/1000) 135 136 /* 137 * Precalculate scale factor (in Gauss units) for each axis and 138 * store in the device data. 139 * 140 * This scale factor is axis-dependent, and is derived from 3 calibration 141 * factors ASA(x), ASA(y), and ASA(z). 142 * 143 * These ASA values are read from the sensor device at start of day, and 144 * cached in the device context struct. 145 * 146 * Adjusting the flux value with the sensitivity adjustment value should be 147 * done via the following formula: 148 * 149 * Hadj = H * ( ( ( (ASA-128)*0.5 ) / 128 ) + 1 ) 150 * where H is the raw value, ASA is the sensitivity adjustment, and Hadj 151 * is the resultant adjusted value. 152 * 153 * We reduce the formula to: 154 * 155 * Hadj = H * (ASA + 128) / 256 156 * 157 * H is in the range of -4096 to 4095. The magnetometer has a range of 158 * +-1229uT. To go from the raw value to uT is: 159 * 160 * HuT = H * 1229/4096, or roughly, 3/10. 161 * 162 * Since 1uT = 0.01 gauss, our final scale factor becomes: 163 * 164 * Hadj = H * ((ASA + 128) / 256) * 3/10 * 1/100 165 * Hadj = H * ((ASA + 128) * 0.003) / 256 166 * 167 * Since ASA doesn't change, we cache the resultant scale factor into the 168 * device context in ak8975_setup(). 169 * 170 * Given we use IIO_VAL_INT_PLUS_MICRO bit when displaying the scale, we 171 * multiply the stored scale value by 1e6. 172 */ 173 static long ak8975_raw_to_gauss(u16 data) 174 { 175 return (((long)data + 128) * 3000) / 256; 176 } 177 178 /* 179 * For AK8963 and AK09911, same calculation, but the device is less sensitive: 180 * 181 * H is in the range of +-8190. The magnetometer has a range of 182 * +-4912uT. To go from the raw value to uT is: 183 * 184 * HuT = H * 4912/8190, or roughly, 6/10, instead of 3/10. 185 */ 186 187 static long ak8963_09911_raw_to_gauss(u16 data) 188 { 189 return (((long)data + 128) * 6000) / 256; 190 } 191 192 /* 193 * For AK09912, same calculation, except the device is more sensitive: 194 * 195 * H is in the range of -32752 to 32752. The magnetometer has a range of 196 * +-4912uT. To go from the raw value to uT is: 197 * 198 * HuT = H * 4912/32752, or roughly, 3/20, instead of 3/10. 199 */ 200 static long ak09912_raw_to_gauss(u16 data) 201 { 202 return (((long)data + 128) * 1500) / 256; 203 } 204 205 /* Compatible Asahi Kasei Compass parts */ 206 enum asahi_compass_chipset { 207 AKXXXX = 0, 208 AK8975, 209 AK8963, 210 AK09911, 211 AK09912, 212 AK09916, 213 }; 214 215 enum ak_ctrl_reg_addr { 216 ST1, 217 ST2, 218 CNTL, 219 ASA_BASE, 220 MAX_REGS, 221 REGS_END, 222 }; 223 224 enum ak_ctrl_reg_mask { 225 ST1_DRDY, 226 ST2_HOFL, 227 ST2_DERR, 228 CNTL_MODE, 229 MASK_END, 230 }; 231 232 enum ak_ctrl_mode { 233 POWER_DOWN, 234 MODE_ONCE, 235 SELF_TEST, 236 FUSE_ROM, 237 MODE_END, 238 }; 239 240 struct ak_def { 241 enum asahi_compass_chipset type; 242 long (*raw_to_gauss)(u16 data); 243 u16 range; 244 u8 ctrl_regs[REGS_END]; 245 u8 ctrl_masks[MASK_END]; 246 u8 ctrl_modes[MODE_END]; 247 u8 data_regs[3]; 248 }; 249 250 static const struct ak_def ak_def_array[] = { 251 { 252 .type = AK8975, 253 .raw_to_gauss = ak8975_raw_to_gauss, 254 .range = 4096, 255 .ctrl_regs = { 256 AK8975_REG_ST1, 257 AK8975_REG_ST2, 258 AK8975_REG_CNTL, 259 AK8975_REG_ASAX, 260 AK8975_MAX_REGS}, 261 .ctrl_masks = { 262 AK8975_REG_ST1_DRDY_MASK, 263 AK8975_REG_ST2_HOFL_MASK, 264 AK8975_REG_ST2_DERR_MASK, 265 AK8975_REG_CNTL_MODE_MASK}, 266 .ctrl_modes = { 267 AK8975_REG_CNTL_MODE_POWER_DOWN, 268 AK8975_REG_CNTL_MODE_ONCE, 269 AK8975_REG_CNTL_MODE_SELF_TEST, 270 AK8975_REG_CNTL_MODE_FUSE_ROM}, 271 .data_regs = { 272 AK8975_REG_HXL, 273 AK8975_REG_HYL, 274 AK8975_REG_HZL}, 275 }, 276 { 277 .type = AK8963, 278 .raw_to_gauss = ak8963_09911_raw_to_gauss, 279 .range = 8190, 280 .ctrl_regs = { 281 AK8975_REG_ST1, 282 AK8975_REG_ST2, 283 AK8975_REG_CNTL, 284 AK8975_REG_ASAX, 285 AK8975_MAX_REGS}, 286 .ctrl_masks = { 287 AK8975_REG_ST1_DRDY_MASK, 288 AK8975_REG_ST2_HOFL_MASK, 289 0, 290 AK8975_REG_CNTL_MODE_MASK}, 291 .ctrl_modes = { 292 AK8975_REG_CNTL_MODE_POWER_DOWN, 293 AK8975_REG_CNTL_MODE_ONCE, 294 AK8975_REG_CNTL_MODE_SELF_TEST, 295 AK8975_REG_CNTL_MODE_FUSE_ROM}, 296 .data_regs = { 297 AK8975_REG_HXL, 298 AK8975_REG_HYL, 299 AK8975_REG_HZL}, 300 }, 301 { 302 .type = AK09911, 303 .raw_to_gauss = ak8963_09911_raw_to_gauss, 304 .range = 8192, 305 .ctrl_regs = { 306 AK09912_REG_ST1, 307 AK09912_REG_ST2, 308 AK09912_REG_CNTL2, 309 AK09912_REG_ASAX, 310 AK09912_MAX_REGS}, 311 .ctrl_masks = { 312 AK09912_REG_ST1_DRDY_MASK, 313 AK09912_REG_ST2_HOFL_MASK, 314 0, 315 AK09912_REG_CNTL2_MODE_MASK}, 316 .ctrl_modes = { 317 AK09912_REG_CNTL_MODE_POWER_DOWN, 318 AK09912_REG_CNTL_MODE_ONCE, 319 AK09912_REG_CNTL_MODE_SELF_TEST, 320 AK09912_REG_CNTL_MODE_FUSE_ROM}, 321 .data_regs = { 322 AK09912_REG_HXL, 323 AK09912_REG_HYL, 324 AK09912_REG_HZL}, 325 }, 326 { 327 .type = AK09912, 328 .raw_to_gauss = ak09912_raw_to_gauss, 329 .range = 32752, 330 .ctrl_regs = { 331 AK09912_REG_ST1, 332 AK09912_REG_ST2, 333 AK09912_REG_CNTL2, 334 AK09912_REG_ASAX, 335 AK09912_MAX_REGS}, 336 .ctrl_masks = { 337 AK09912_REG_ST1_DRDY_MASK, 338 AK09912_REG_ST2_HOFL_MASK, 339 0, 340 AK09912_REG_CNTL2_MODE_MASK}, 341 .ctrl_modes = { 342 AK09912_REG_CNTL_MODE_POWER_DOWN, 343 AK09912_REG_CNTL_MODE_ONCE, 344 AK09912_REG_CNTL_MODE_SELF_TEST, 345 AK09912_REG_CNTL_MODE_FUSE_ROM}, 346 .data_regs = { 347 AK09912_REG_HXL, 348 AK09912_REG_HYL, 349 AK09912_REG_HZL}, 350 }, 351 { 352 .type = AK09916, 353 .raw_to_gauss = ak09912_raw_to_gauss, 354 .range = 32752, 355 .ctrl_regs = { 356 AK09912_REG_ST1, 357 AK09912_REG_ST2, 358 AK09912_REG_CNTL2, 359 AK09912_REG_ASAX, 360 AK09912_MAX_REGS}, 361 .ctrl_masks = { 362 AK09912_REG_ST1_DRDY_MASK, 363 AK09912_REG_ST2_HOFL_MASK, 364 0, 365 AK09912_REG_CNTL2_MODE_MASK}, 366 .ctrl_modes = { 367 AK09912_REG_CNTL_MODE_POWER_DOWN, 368 AK09912_REG_CNTL_MODE_ONCE, 369 AK09912_REG_CNTL_MODE_SELF_TEST, 370 AK09912_REG_CNTL_MODE_FUSE_ROM}, 371 .data_regs = { 372 AK09912_REG_HXL, 373 AK09912_REG_HYL, 374 AK09912_REG_HZL}, 375 } 376 }; 377 378 /* 379 * Per-instance context data for the device. 380 */ 381 struct ak8975_data { 382 struct i2c_client *client; 383 const struct ak_def *def; 384 struct mutex lock; 385 u8 asa[3]; 386 long raw_to_gauss[3]; 387 struct gpio_desc *eoc_gpiod; 388 struct gpio_desc *reset_gpiod; 389 int eoc_irq; 390 wait_queue_head_t data_ready_queue; 391 unsigned long flags; 392 u8 cntl_cache; 393 struct iio_mount_matrix orientation; 394 struct regulator *vdd; 395 struct regulator *vid; 396 397 /* Ensure natural alignment of timestamp */ 398 struct { 399 s16 channels[3]; 400 s64 ts __aligned(8); 401 } scan; 402 }; 403 404 /* Enable attached power regulator if any. */ 405 static int ak8975_power_on(const struct ak8975_data *data) 406 { 407 int ret; 408 409 ret = regulator_enable(data->vdd); 410 if (ret) { 411 dev_warn(&data->client->dev, 412 "Failed to enable specified Vdd supply\n"); 413 return ret; 414 } 415 ret = regulator_enable(data->vid); 416 if (ret) { 417 dev_warn(&data->client->dev, 418 "Failed to enable specified Vid supply\n"); 419 regulator_disable(data->vdd); 420 return ret; 421 } 422 423 gpiod_set_value_cansleep(data->reset_gpiod, 0); 424 425 /* 426 * According to the datasheet the power supply rise time is 200us 427 * and the minimum wait time before mode setting is 100us, in 428 * total 300us. Add some margin and say minimum 500us here. 429 */ 430 usleep_range(500, 1000); 431 return 0; 432 } 433 434 /* Disable attached power regulator if any. */ 435 static void ak8975_power_off(const struct ak8975_data *data) 436 { 437 gpiod_set_value_cansleep(data->reset_gpiod, 1); 438 439 regulator_disable(data->vid); 440 regulator_disable(data->vdd); 441 } 442 443 /* 444 * Return 0 if the i2c device is the one we expect. 445 * return a negative error number otherwise 446 */ 447 static int ak8975_who_i_am(struct i2c_client *client, 448 enum asahi_compass_chipset type) 449 { 450 u8 wia_val[2]; 451 int ret; 452 453 /* 454 * Signature for each device: 455 * Device | WIA1 | WIA2 456 * AK09916 | DEVICE_ID_| AK09916_DEVICE_ID 457 * AK09912 | DEVICE_ID | AK09912_DEVICE_ID 458 * AK09911 | DEVICE_ID | AK09911_DEVICE_ID 459 * AK8975 | DEVICE_ID | NA 460 * AK8963 | DEVICE_ID | NA 461 */ 462 ret = i2c_smbus_read_i2c_block_data_or_emulated( 463 client, AK09912_REG_WIA1, 2, wia_val); 464 if (ret < 0) { 465 dev_err(&client->dev, "Error reading WIA\n"); 466 return ret; 467 } 468 469 if (wia_val[0] != AK8975_DEVICE_ID) 470 return -ENODEV; 471 472 switch (type) { 473 case AK8975: 474 case AK8963: 475 return 0; 476 case AK09911: 477 if (wia_val[1] == AK09911_DEVICE_ID) 478 return 0; 479 break; 480 case AK09912: 481 if (wia_val[1] == AK09912_DEVICE_ID) 482 return 0; 483 break; 484 case AK09916: 485 if (wia_val[1] == AK09916_DEVICE_ID) 486 return 0; 487 break; 488 default: 489 dev_err(&client->dev, "Type %d unknown\n", type); 490 } 491 return -ENODEV; 492 } 493 494 /* 495 * Helper function to write to CNTL register. 496 */ 497 static int ak8975_set_mode(struct ak8975_data *data, enum ak_ctrl_mode mode) 498 { 499 u8 regval; 500 int ret; 501 502 regval = (data->cntl_cache & ~data->def->ctrl_masks[CNTL_MODE]) | 503 data->def->ctrl_modes[mode]; 504 ret = i2c_smbus_write_byte_data(data->client, 505 data->def->ctrl_regs[CNTL], regval); 506 if (ret < 0) { 507 return ret; 508 } 509 data->cntl_cache = regval; 510 /* After mode change wait atleast 100us */ 511 usleep_range(100, 500); 512 513 return 0; 514 } 515 516 /* 517 * Handle data ready irq 518 */ 519 static irqreturn_t ak8975_irq_handler(int irq, void *data) 520 { 521 struct ak8975_data *ak8975 = data; 522 523 set_bit(0, &ak8975->flags); 524 wake_up(&ak8975->data_ready_queue); 525 526 return IRQ_HANDLED; 527 } 528 529 /* 530 * Install data ready interrupt handler 531 */ 532 static int ak8975_setup_irq(struct ak8975_data *data) 533 { 534 struct i2c_client *client = data->client; 535 int rc; 536 int irq; 537 538 init_waitqueue_head(&data->data_ready_queue); 539 clear_bit(0, &data->flags); 540 if (client->irq) 541 irq = client->irq; 542 else 543 irq = gpiod_to_irq(data->eoc_gpiod); 544 545 rc = devm_request_irq(&client->dev, irq, ak8975_irq_handler, 546 IRQF_TRIGGER_RISING | IRQF_ONESHOT, 547 dev_name(&client->dev), data); 548 if (rc < 0) { 549 dev_err(&client->dev, "irq %d request failed: %d\n", irq, rc); 550 return rc; 551 } 552 553 data->eoc_irq = irq; 554 555 return rc; 556 } 557 558 559 /* 560 * Perform some start-of-day setup, including reading the asa calibration 561 * values and caching them. 562 */ 563 static int ak8975_setup(struct i2c_client *client) 564 { 565 struct iio_dev *indio_dev = i2c_get_clientdata(client); 566 struct ak8975_data *data = iio_priv(indio_dev); 567 int ret; 568 569 /* Write the fused rom access mode. */ 570 ret = ak8975_set_mode(data, FUSE_ROM); 571 if (ret < 0) { 572 dev_err(&client->dev, "Error in setting fuse access mode\n"); 573 return ret; 574 } 575 576 /* Get asa data and store in the device data. */ 577 ret = i2c_smbus_read_i2c_block_data_or_emulated( 578 client, data->def->ctrl_regs[ASA_BASE], 579 3, data->asa); 580 if (ret < 0) { 581 dev_err(&client->dev, "Not able to read asa data\n"); 582 return ret; 583 } 584 585 /* After reading fuse ROM data set power-down mode */ 586 ret = ak8975_set_mode(data, POWER_DOWN); 587 if (ret < 0) { 588 dev_err(&client->dev, "Error in setting power-down mode\n"); 589 return ret; 590 } 591 592 if (data->eoc_gpiod || client->irq > 0) { 593 ret = ak8975_setup_irq(data); 594 if (ret < 0) { 595 dev_err(&client->dev, 596 "Error setting data ready interrupt\n"); 597 return ret; 598 } 599 } 600 601 data->raw_to_gauss[0] = data->def->raw_to_gauss(data->asa[0]); 602 data->raw_to_gauss[1] = data->def->raw_to_gauss(data->asa[1]); 603 data->raw_to_gauss[2] = data->def->raw_to_gauss(data->asa[2]); 604 605 return 0; 606 } 607 608 static int wait_conversion_complete_gpio(struct ak8975_data *data) 609 { 610 struct i2c_client *client = data->client; 611 u32 timeout_ms = AK8975_MAX_CONVERSION_TIMEOUT; 612 int ret; 613 614 /* Wait for the conversion to complete. */ 615 while (timeout_ms) { 616 msleep(AK8975_CONVERSION_DONE_POLL_TIME); 617 if (gpiod_get_value(data->eoc_gpiod)) 618 break; 619 timeout_ms -= AK8975_CONVERSION_DONE_POLL_TIME; 620 } 621 if (!timeout_ms) { 622 dev_err(&client->dev, "Conversion timeout happened\n"); 623 return -EINVAL; 624 } 625 626 ret = i2c_smbus_read_byte_data(client, data->def->ctrl_regs[ST1]); 627 if (ret < 0) 628 dev_err(&client->dev, "Error in reading ST1\n"); 629 630 return ret; 631 } 632 633 static int wait_conversion_complete_polled(struct ak8975_data *data) 634 { 635 struct i2c_client *client = data->client; 636 u8 read_status; 637 u32 timeout_ms = AK8975_MAX_CONVERSION_TIMEOUT; 638 int ret; 639 640 /* Wait for the conversion to complete. */ 641 while (timeout_ms) { 642 msleep(AK8975_CONVERSION_DONE_POLL_TIME); 643 ret = i2c_smbus_read_byte_data(client, 644 data->def->ctrl_regs[ST1]); 645 if (ret < 0) { 646 dev_err(&client->dev, "Error in reading ST1\n"); 647 return ret; 648 } 649 read_status = ret; 650 if (read_status) 651 break; 652 timeout_ms -= AK8975_CONVERSION_DONE_POLL_TIME; 653 } 654 if (!timeout_ms) { 655 dev_err(&client->dev, "Conversion timeout happened\n"); 656 return -EINVAL; 657 } 658 659 return read_status; 660 } 661 662 /* Returns 0 if the end of conversion interrupt occured or -ETIME otherwise */ 663 static int wait_conversion_complete_interrupt(struct ak8975_data *data) 664 { 665 int ret; 666 667 ret = wait_event_timeout(data->data_ready_queue, 668 test_bit(0, &data->flags), 669 AK8975_DATA_READY_TIMEOUT); 670 clear_bit(0, &data->flags); 671 672 return ret > 0 ? 0 : -ETIME; 673 } 674 675 static int ak8975_start_read_axis(struct ak8975_data *data, 676 const struct i2c_client *client) 677 { 678 /* Set up the device for taking a sample. */ 679 int ret = ak8975_set_mode(data, MODE_ONCE); 680 681 if (ret < 0) { 682 dev_err(&client->dev, "Error in setting operating mode\n"); 683 return ret; 684 } 685 686 /* Wait for the conversion to complete. */ 687 if (data->eoc_irq) 688 ret = wait_conversion_complete_interrupt(data); 689 else if (data->eoc_gpiod) 690 ret = wait_conversion_complete_gpio(data); 691 else 692 ret = wait_conversion_complete_polled(data); 693 if (ret < 0) 694 return ret; 695 696 /* This will be executed only for non-interrupt based waiting case */ 697 if (ret & data->def->ctrl_masks[ST1_DRDY]) { 698 ret = i2c_smbus_read_byte_data(client, 699 data->def->ctrl_regs[ST2]); 700 if (ret < 0) { 701 dev_err(&client->dev, "Error in reading ST2\n"); 702 return ret; 703 } 704 if (ret & (data->def->ctrl_masks[ST2_DERR] | 705 data->def->ctrl_masks[ST2_HOFL])) { 706 dev_err(&client->dev, "ST2 status error 0x%x\n", ret); 707 return -EINVAL; 708 } 709 } 710 711 return 0; 712 } 713 714 /* Retrieve raw flux value for one of the x, y, or z axis. */ 715 static int ak8975_read_axis(struct iio_dev *indio_dev, int index, int *val) 716 { 717 struct ak8975_data *data = iio_priv(indio_dev); 718 const struct i2c_client *client = data->client; 719 const struct ak_def *def = data->def; 720 __le16 rval; 721 u16 buff; 722 int ret; 723 724 pm_runtime_get_sync(&data->client->dev); 725 726 mutex_lock(&data->lock); 727 728 ret = ak8975_start_read_axis(data, client); 729 if (ret) 730 goto exit; 731 732 ret = i2c_smbus_read_i2c_block_data_or_emulated( 733 client, def->data_regs[index], 734 sizeof(rval), (u8*)&rval); 735 if (ret < 0) 736 goto exit; 737 738 mutex_unlock(&data->lock); 739 740 pm_runtime_mark_last_busy(&data->client->dev); 741 pm_runtime_put_autosuspend(&data->client->dev); 742 743 /* Swap bytes and convert to valid range. */ 744 buff = le16_to_cpu(rval); 745 *val = clamp_t(s16, buff, -def->range, def->range); 746 return IIO_VAL_INT; 747 748 exit: 749 mutex_unlock(&data->lock); 750 dev_err(&client->dev, "Error in reading axis\n"); 751 return ret; 752 } 753 754 static int ak8975_read_raw(struct iio_dev *indio_dev, 755 struct iio_chan_spec const *chan, 756 int *val, int *val2, 757 long mask) 758 { 759 struct ak8975_data *data = iio_priv(indio_dev); 760 761 switch (mask) { 762 case IIO_CHAN_INFO_RAW: 763 return ak8975_read_axis(indio_dev, chan->address, val); 764 case IIO_CHAN_INFO_SCALE: 765 *val = 0; 766 *val2 = data->raw_to_gauss[chan->address]; 767 return IIO_VAL_INT_PLUS_MICRO; 768 } 769 return -EINVAL; 770 } 771 772 static const struct iio_mount_matrix * 773 ak8975_get_mount_matrix(const struct iio_dev *indio_dev, 774 const struct iio_chan_spec *chan) 775 { 776 struct ak8975_data *data = iio_priv(indio_dev); 777 778 return &data->orientation; 779 } 780 781 static const struct iio_chan_spec_ext_info ak8975_ext_info[] = { 782 IIO_MOUNT_MATRIX(IIO_SHARED_BY_DIR, ak8975_get_mount_matrix), 783 { } 784 }; 785 786 #define AK8975_CHANNEL(axis, index) \ 787 { \ 788 .type = IIO_MAGN, \ 789 .modified = 1, \ 790 .channel2 = IIO_MOD_##axis, \ 791 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \ 792 BIT(IIO_CHAN_INFO_SCALE), \ 793 .address = index, \ 794 .scan_index = index, \ 795 .scan_type = { \ 796 .sign = 's', \ 797 .realbits = 16, \ 798 .storagebits = 16, \ 799 .endianness = IIO_CPU \ 800 }, \ 801 .ext_info = ak8975_ext_info, \ 802 } 803 804 static const struct iio_chan_spec ak8975_channels[] = { 805 AK8975_CHANNEL(X, 0), AK8975_CHANNEL(Y, 1), AK8975_CHANNEL(Z, 2), 806 IIO_CHAN_SOFT_TIMESTAMP(3), 807 }; 808 809 static const unsigned long ak8975_scan_masks[] = { 0x7, 0 }; 810 811 static const struct iio_info ak8975_info = { 812 .read_raw = &ak8975_read_raw, 813 }; 814 815 static const struct acpi_device_id ak_acpi_match[] = { 816 {"AK8975", AK8975}, 817 {"AK8963", AK8963}, 818 {"INVN6500", AK8963}, 819 {"AK009911", AK09911}, 820 {"AK09911", AK09911}, 821 {"AKM9911", AK09911}, 822 {"AK09912", AK09912}, 823 { } 824 }; 825 MODULE_DEVICE_TABLE(acpi, ak_acpi_match); 826 827 static void ak8975_fill_buffer(struct iio_dev *indio_dev) 828 { 829 struct ak8975_data *data = iio_priv(indio_dev); 830 const struct i2c_client *client = data->client; 831 const struct ak_def *def = data->def; 832 int ret; 833 __le16 fval[3]; 834 835 mutex_lock(&data->lock); 836 837 ret = ak8975_start_read_axis(data, client); 838 if (ret) 839 goto unlock; 840 841 /* 842 * For each axis, read the flux value from the appropriate register 843 * (the register is specified in the iio device attributes). 844 */ 845 ret = i2c_smbus_read_i2c_block_data_or_emulated(client, 846 def->data_regs[0], 847 3 * sizeof(fval[0]), 848 (u8 *)fval); 849 if (ret < 0) 850 goto unlock; 851 852 mutex_unlock(&data->lock); 853 854 /* Clamp to valid range. */ 855 data->scan.channels[0] = clamp_t(s16, le16_to_cpu(fval[0]), -def->range, def->range); 856 data->scan.channels[1] = clamp_t(s16, le16_to_cpu(fval[1]), -def->range, def->range); 857 data->scan.channels[2] = clamp_t(s16, le16_to_cpu(fval[2]), -def->range, def->range); 858 859 iio_push_to_buffers_with_timestamp(indio_dev, &data->scan, 860 iio_get_time_ns(indio_dev)); 861 862 return; 863 864 unlock: 865 mutex_unlock(&data->lock); 866 dev_err(&client->dev, "Error in reading axes block\n"); 867 } 868 869 static irqreturn_t ak8975_handle_trigger(int irq, void *p) 870 { 871 const struct iio_poll_func *pf = p; 872 struct iio_dev *indio_dev = pf->indio_dev; 873 874 ak8975_fill_buffer(indio_dev); 875 iio_trigger_notify_done(indio_dev->trig); 876 return IRQ_HANDLED; 877 } 878 879 static int ak8975_probe(struct i2c_client *client, 880 const struct i2c_device_id *id) 881 { 882 struct ak8975_data *data; 883 struct iio_dev *indio_dev; 884 struct gpio_desc *eoc_gpiod; 885 struct gpio_desc *reset_gpiod; 886 const void *match; 887 unsigned int i; 888 int err; 889 enum asahi_compass_chipset chipset; 890 const char *name = NULL; 891 892 /* 893 * Grab and set up the supplied GPIO. 894 * We may not have a GPIO based IRQ to scan, that is fine, we will 895 * poll if so. 896 */ 897 eoc_gpiod = devm_gpiod_get_optional(&client->dev, NULL, GPIOD_IN); 898 if (IS_ERR(eoc_gpiod)) 899 return PTR_ERR(eoc_gpiod); 900 if (eoc_gpiod) 901 gpiod_set_consumer_name(eoc_gpiod, "ak_8975"); 902 903 /* 904 * According to AK09911 datasheet, if reset GPIO is provided then 905 * deassert reset on ak8975_power_on() and assert reset on 906 * ak8975_power_off(). 907 */ 908 reset_gpiod = devm_gpiod_get_optional(&client->dev, 909 "reset", GPIOD_OUT_HIGH); 910 if (IS_ERR(reset_gpiod)) 911 return PTR_ERR(reset_gpiod); 912 913 /* Register with IIO */ 914 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data)); 915 if (indio_dev == NULL) 916 return -ENOMEM; 917 918 data = iio_priv(indio_dev); 919 i2c_set_clientdata(client, indio_dev); 920 921 data->client = client; 922 data->eoc_gpiod = eoc_gpiod; 923 data->reset_gpiod = reset_gpiod; 924 data->eoc_irq = 0; 925 926 err = iio_read_mount_matrix(&client->dev, &data->orientation); 927 if (err) 928 return err; 929 930 /* id will be NULL when enumerated via ACPI */ 931 match = device_get_match_data(&client->dev); 932 if (match) { 933 chipset = (uintptr_t)match; 934 name = dev_name(&client->dev); 935 } else if (id) { 936 chipset = (enum asahi_compass_chipset)(id->driver_data); 937 name = id->name; 938 } else 939 return -ENOSYS; 940 941 for (i = 0; i < ARRAY_SIZE(ak_def_array); i++) 942 if (ak_def_array[i].type == chipset) 943 break; 944 945 if (i == ARRAY_SIZE(ak_def_array)) { 946 dev_err(&client->dev, "AKM device type unsupported: %d\n", 947 chipset); 948 return -ENODEV; 949 } 950 951 data->def = &ak_def_array[i]; 952 953 /* Fetch the regulators */ 954 data->vdd = devm_regulator_get(&client->dev, "vdd"); 955 if (IS_ERR(data->vdd)) 956 return PTR_ERR(data->vdd); 957 data->vid = devm_regulator_get(&client->dev, "vid"); 958 if (IS_ERR(data->vid)) 959 return PTR_ERR(data->vid); 960 961 err = ak8975_power_on(data); 962 if (err) 963 return err; 964 965 err = ak8975_who_i_am(client, data->def->type); 966 if (err < 0) { 967 dev_err(&client->dev, "Unexpected device\n"); 968 goto power_off; 969 } 970 dev_dbg(&client->dev, "Asahi compass chip %s\n", name); 971 972 /* Perform some basic start-of-day setup of the device. */ 973 err = ak8975_setup(client); 974 if (err < 0) { 975 dev_err(&client->dev, "%s initialization fails\n", name); 976 goto power_off; 977 } 978 979 mutex_init(&data->lock); 980 indio_dev->channels = ak8975_channels; 981 indio_dev->num_channels = ARRAY_SIZE(ak8975_channels); 982 indio_dev->info = &ak8975_info; 983 indio_dev->available_scan_masks = ak8975_scan_masks; 984 indio_dev->modes = INDIO_DIRECT_MODE; 985 indio_dev->name = name; 986 987 err = iio_triggered_buffer_setup(indio_dev, NULL, ak8975_handle_trigger, 988 NULL); 989 if (err) { 990 dev_err(&client->dev, "triggered buffer setup failed\n"); 991 goto power_off; 992 } 993 994 err = iio_device_register(indio_dev); 995 if (err) { 996 dev_err(&client->dev, "device register failed\n"); 997 goto cleanup_buffer; 998 } 999 1000 /* Enable runtime PM */ 1001 pm_runtime_get_noresume(&client->dev); 1002 pm_runtime_set_active(&client->dev); 1003 pm_runtime_enable(&client->dev); 1004 /* 1005 * The device comes online in 500us, so add two orders of magnitude 1006 * of delay before autosuspending: 50 ms. 1007 */ 1008 pm_runtime_set_autosuspend_delay(&client->dev, 50); 1009 pm_runtime_use_autosuspend(&client->dev); 1010 pm_runtime_put(&client->dev); 1011 1012 return 0; 1013 1014 cleanup_buffer: 1015 iio_triggered_buffer_cleanup(indio_dev); 1016 power_off: 1017 ak8975_power_off(data); 1018 return err; 1019 } 1020 1021 static int ak8975_remove(struct i2c_client *client) 1022 { 1023 struct iio_dev *indio_dev = i2c_get_clientdata(client); 1024 struct ak8975_data *data = iio_priv(indio_dev); 1025 1026 pm_runtime_get_sync(&client->dev); 1027 pm_runtime_put_noidle(&client->dev); 1028 pm_runtime_disable(&client->dev); 1029 iio_device_unregister(indio_dev); 1030 iio_triggered_buffer_cleanup(indio_dev); 1031 ak8975_set_mode(data, POWER_DOWN); 1032 ak8975_power_off(data); 1033 1034 return 0; 1035 } 1036 1037 static int ak8975_runtime_suspend(struct device *dev) 1038 { 1039 struct i2c_client *client = to_i2c_client(dev); 1040 struct iio_dev *indio_dev = i2c_get_clientdata(client); 1041 struct ak8975_data *data = iio_priv(indio_dev); 1042 int ret; 1043 1044 /* Set the device in power down if it wasn't already */ 1045 ret = ak8975_set_mode(data, POWER_DOWN); 1046 if (ret < 0) { 1047 dev_err(&client->dev, "Error in setting power-down mode\n"); 1048 return ret; 1049 } 1050 /* Next cut the regulators */ 1051 ak8975_power_off(data); 1052 1053 return 0; 1054 } 1055 1056 static int ak8975_runtime_resume(struct device *dev) 1057 { 1058 struct i2c_client *client = to_i2c_client(dev); 1059 struct iio_dev *indio_dev = i2c_get_clientdata(client); 1060 struct ak8975_data *data = iio_priv(indio_dev); 1061 int ret; 1062 1063 /* Take up the regulators */ 1064 ak8975_power_on(data); 1065 /* 1066 * We come up in powered down mode, the reading routines will 1067 * put us in the mode to read values later. 1068 */ 1069 ret = ak8975_set_mode(data, POWER_DOWN); 1070 if (ret < 0) { 1071 dev_err(&client->dev, "Error in setting power-down mode\n"); 1072 return ret; 1073 } 1074 1075 return 0; 1076 } 1077 1078 static DEFINE_RUNTIME_DEV_PM_OPS(ak8975_dev_pm_ops, ak8975_runtime_suspend, 1079 ak8975_runtime_resume, NULL); 1080 1081 static const struct i2c_device_id ak8975_id[] = { 1082 {"ak8975", AK8975}, 1083 {"ak8963", AK8963}, 1084 {"AK8963", AK8963}, 1085 {"ak09911", AK09911}, 1086 {"ak09912", AK09912}, 1087 {"ak09916", AK09916}, 1088 {} 1089 }; 1090 1091 MODULE_DEVICE_TABLE(i2c, ak8975_id); 1092 1093 static const struct of_device_id ak8975_of_match[] = { 1094 { .compatible = "asahi-kasei,ak8975", }, 1095 { .compatible = "ak8975", }, 1096 { .compatible = "asahi-kasei,ak8963", }, 1097 { .compatible = "ak8963", }, 1098 { .compatible = "asahi-kasei,ak09911", }, 1099 { .compatible = "ak09911", }, 1100 { .compatible = "asahi-kasei,ak09912", }, 1101 { .compatible = "ak09912", }, 1102 { .compatible = "asahi-kasei,ak09916", }, 1103 { .compatible = "ak09916", }, 1104 {} 1105 }; 1106 MODULE_DEVICE_TABLE(of, ak8975_of_match); 1107 1108 static struct i2c_driver ak8975_driver = { 1109 .driver = { 1110 .name = "ak8975", 1111 .pm = pm_ptr(&ak8975_dev_pm_ops), 1112 .of_match_table = ak8975_of_match, 1113 .acpi_match_table = ak_acpi_match, 1114 }, 1115 .probe = ak8975_probe, 1116 .remove = ak8975_remove, 1117 .id_table = ak8975_id, 1118 }; 1119 module_i2c_driver(ak8975_driver); 1120 1121 MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>"); 1122 MODULE_DESCRIPTION("AK8975 magnetometer driver"); 1123 MODULE_LICENSE("GPL"); 1124