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