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 return ret; 420 } 421 422 gpiod_set_value_cansleep(data->reset_gpiod, 0); 423 424 /* 425 * According to the datasheet the power supply rise time is 200us 426 * and the minimum wait time before mode setting is 100us, in 427 * total 300us. Add some margin and say minimum 500us here. 428 */ 429 usleep_range(500, 1000); 430 return 0; 431 } 432 433 /* Disable attached power regulator if any. */ 434 static void ak8975_power_off(const struct ak8975_data *data) 435 { 436 gpiod_set_value_cansleep(data->reset_gpiod, 1); 437 438 regulator_disable(data->vid); 439 regulator_disable(data->vdd); 440 } 441 442 /* 443 * Return 0 if the i2c device is the one we expect. 444 * return a negative error number otherwise 445 */ 446 static int ak8975_who_i_am(struct i2c_client *client, 447 enum asahi_compass_chipset type) 448 { 449 u8 wia_val[2]; 450 int ret; 451 452 /* 453 * Signature for each device: 454 * Device | WIA1 | WIA2 455 * AK09916 | DEVICE_ID_| AK09916_DEVICE_ID 456 * AK09912 | DEVICE_ID | AK09912_DEVICE_ID 457 * AK09911 | DEVICE_ID | AK09911_DEVICE_ID 458 * AK8975 | DEVICE_ID | NA 459 * AK8963 | DEVICE_ID | NA 460 */ 461 ret = i2c_smbus_read_i2c_block_data_or_emulated( 462 client, AK09912_REG_WIA1, 2, wia_val); 463 if (ret < 0) { 464 dev_err(&client->dev, "Error reading WIA\n"); 465 return ret; 466 } 467 468 if (wia_val[0] != AK8975_DEVICE_ID) 469 return -ENODEV; 470 471 switch (type) { 472 case AK8975: 473 case AK8963: 474 return 0; 475 case AK09911: 476 if (wia_val[1] == AK09911_DEVICE_ID) 477 return 0; 478 break; 479 case AK09912: 480 if (wia_val[1] == AK09912_DEVICE_ID) 481 return 0; 482 break; 483 case AK09916: 484 if (wia_val[1] == AK09916_DEVICE_ID) 485 return 0; 486 break; 487 default: 488 dev_err(&client->dev, "Type %d unknown\n", type); 489 } 490 return -ENODEV; 491 } 492 493 /* 494 * Helper function to write to CNTL register. 495 */ 496 static int ak8975_set_mode(struct ak8975_data *data, enum ak_ctrl_mode mode) 497 { 498 u8 regval; 499 int ret; 500 501 regval = (data->cntl_cache & ~data->def->ctrl_masks[CNTL_MODE]) | 502 data->def->ctrl_modes[mode]; 503 ret = i2c_smbus_write_byte_data(data->client, 504 data->def->ctrl_regs[CNTL], regval); 505 if (ret < 0) { 506 return ret; 507 } 508 data->cntl_cache = regval; 509 /* After mode change wait atleast 100us */ 510 usleep_range(100, 500); 511 512 return 0; 513 } 514 515 /* 516 * Handle data ready irq 517 */ 518 static irqreturn_t ak8975_irq_handler(int irq, void *data) 519 { 520 struct ak8975_data *ak8975 = data; 521 522 set_bit(0, &ak8975->flags); 523 wake_up(&ak8975->data_ready_queue); 524 525 return IRQ_HANDLED; 526 } 527 528 /* 529 * Install data ready interrupt handler 530 */ 531 static int ak8975_setup_irq(struct ak8975_data *data) 532 { 533 struct i2c_client *client = data->client; 534 int rc; 535 int irq; 536 537 init_waitqueue_head(&data->data_ready_queue); 538 clear_bit(0, &data->flags); 539 if (client->irq) 540 irq = client->irq; 541 else 542 irq = gpiod_to_irq(data->eoc_gpiod); 543 544 rc = devm_request_irq(&client->dev, irq, ak8975_irq_handler, 545 IRQF_TRIGGER_RISING | IRQF_ONESHOT, 546 dev_name(&client->dev), data); 547 if (rc < 0) { 548 dev_err(&client->dev, "irq %d request failed: %d\n", irq, rc); 549 return rc; 550 } 551 552 data->eoc_irq = irq; 553 554 return rc; 555 } 556 557 558 /* 559 * Perform some start-of-day setup, including reading the asa calibration 560 * values and caching them. 561 */ 562 static int ak8975_setup(struct i2c_client *client) 563 { 564 struct iio_dev *indio_dev = i2c_get_clientdata(client); 565 struct ak8975_data *data = iio_priv(indio_dev); 566 int ret; 567 568 /* Write the fused rom access mode. */ 569 ret = ak8975_set_mode(data, FUSE_ROM); 570 if (ret < 0) { 571 dev_err(&client->dev, "Error in setting fuse access mode\n"); 572 return ret; 573 } 574 575 /* Get asa data and store in the device data. */ 576 ret = i2c_smbus_read_i2c_block_data_or_emulated( 577 client, data->def->ctrl_regs[ASA_BASE], 578 3, data->asa); 579 if (ret < 0) { 580 dev_err(&client->dev, "Not able to read asa data\n"); 581 return ret; 582 } 583 584 /* After reading fuse ROM data set power-down mode */ 585 ret = ak8975_set_mode(data, POWER_DOWN); 586 if (ret < 0) { 587 dev_err(&client->dev, "Error in setting power-down mode\n"); 588 return ret; 589 } 590 591 if (data->eoc_gpiod || client->irq > 0) { 592 ret = ak8975_setup_irq(data); 593 if (ret < 0) { 594 dev_err(&client->dev, 595 "Error setting data ready interrupt\n"); 596 return ret; 597 } 598 } 599 600 data->raw_to_gauss[0] = data->def->raw_to_gauss(data->asa[0]); 601 data->raw_to_gauss[1] = data->def->raw_to_gauss(data->asa[1]); 602 data->raw_to_gauss[2] = data->def->raw_to_gauss(data->asa[2]); 603 604 return 0; 605 } 606 607 static int wait_conversion_complete_gpio(struct ak8975_data *data) 608 { 609 struct i2c_client *client = data->client; 610 u32 timeout_ms = AK8975_MAX_CONVERSION_TIMEOUT; 611 int ret; 612 613 /* Wait for the conversion to complete. */ 614 while (timeout_ms) { 615 msleep(AK8975_CONVERSION_DONE_POLL_TIME); 616 if (gpiod_get_value(data->eoc_gpiod)) 617 break; 618 timeout_ms -= AK8975_CONVERSION_DONE_POLL_TIME; 619 } 620 if (!timeout_ms) { 621 dev_err(&client->dev, "Conversion timeout happened\n"); 622 return -EINVAL; 623 } 624 625 ret = i2c_smbus_read_byte_data(client, data->def->ctrl_regs[ST1]); 626 if (ret < 0) 627 dev_err(&client->dev, "Error in reading ST1\n"); 628 629 return ret; 630 } 631 632 static int wait_conversion_complete_polled(struct ak8975_data *data) 633 { 634 struct i2c_client *client = data->client; 635 u8 read_status; 636 u32 timeout_ms = AK8975_MAX_CONVERSION_TIMEOUT; 637 int ret; 638 639 /* Wait for the conversion to complete. */ 640 while (timeout_ms) { 641 msleep(AK8975_CONVERSION_DONE_POLL_TIME); 642 ret = i2c_smbus_read_byte_data(client, 643 data->def->ctrl_regs[ST1]); 644 if (ret < 0) { 645 dev_err(&client->dev, "Error in reading ST1\n"); 646 return ret; 647 } 648 read_status = ret; 649 if (read_status) 650 break; 651 timeout_ms -= AK8975_CONVERSION_DONE_POLL_TIME; 652 } 653 if (!timeout_ms) { 654 dev_err(&client->dev, "Conversion timeout happened\n"); 655 return -EINVAL; 656 } 657 658 return read_status; 659 } 660 661 /* Returns 0 if the end of conversion interrupt occured or -ETIME otherwise */ 662 static int wait_conversion_complete_interrupt(struct ak8975_data *data) 663 { 664 int ret; 665 666 ret = wait_event_timeout(data->data_ready_queue, 667 test_bit(0, &data->flags), 668 AK8975_DATA_READY_TIMEOUT); 669 clear_bit(0, &data->flags); 670 671 return ret > 0 ? 0 : -ETIME; 672 } 673 674 static int ak8975_start_read_axis(struct ak8975_data *data, 675 const struct i2c_client *client) 676 { 677 /* Set up the device for taking a sample. */ 678 int ret = ak8975_set_mode(data, MODE_ONCE); 679 680 if (ret < 0) { 681 dev_err(&client->dev, "Error in setting operating mode\n"); 682 return ret; 683 } 684 685 /* Wait for the conversion to complete. */ 686 if (data->eoc_irq) 687 ret = wait_conversion_complete_interrupt(data); 688 else if (data->eoc_gpiod) 689 ret = wait_conversion_complete_gpio(data); 690 else 691 ret = wait_conversion_complete_polled(data); 692 if (ret < 0) 693 return ret; 694 695 /* This will be executed only for non-interrupt based waiting case */ 696 if (ret & data->def->ctrl_masks[ST1_DRDY]) { 697 ret = i2c_smbus_read_byte_data(client, 698 data->def->ctrl_regs[ST2]); 699 if (ret < 0) { 700 dev_err(&client->dev, "Error in reading ST2\n"); 701 return ret; 702 } 703 if (ret & (data->def->ctrl_masks[ST2_DERR] | 704 data->def->ctrl_masks[ST2_HOFL])) { 705 dev_err(&client->dev, "ST2 status error 0x%x\n", ret); 706 return -EINVAL; 707 } 708 } 709 710 return 0; 711 } 712 713 /* Retrieve raw flux value for one of the x, y, or z axis. */ 714 static int ak8975_read_axis(struct iio_dev *indio_dev, int index, int *val) 715 { 716 struct ak8975_data *data = iio_priv(indio_dev); 717 const struct i2c_client *client = data->client; 718 const struct ak_def *def = data->def; 719 __le16 rval; 720 u16 buff; 721 int ret; 722 723 pm_runtime_get_sync(&data->client->dev); 724 725 mutex_lock(&data->lock); 726 727 ret = ak8975_start_read_axis(data, client); 728 if (ret) 729 goto exit; 730 731 ret = i2c_smbus_read_i2c_block_data_or_emulated( 732 client, def->data_regs[index], 733 sizeof(rval), (u8*)&rval); 734 if (ret < 0) 735 goto exit; 736 737 mutex_unlock(&data->lock); 738 739 pm_runtime_mark_last_busy(&data->client->dev); 740 pm_runtime_put_autosuspend(&data->client->dev); 741 742 /* Swap bytes and convert to valid range. */ 743 buff = le16_to_cpu(rval); 744 *val = clamp_t(s16, buff, -def->range, def->range); 745 return IIO_VAL_INT; 746 747 exit: 748 mutex_unlock(&data->lock); 749 dev_err(&client->dev, "Error in reading axis\n"); 750 return ret; 751 } 752 753 static int ak8975_read_raw(struct iio_dev *indio_dev, 754 struct iio_chan_spec const *chan, 755 int *val, int *val2, 756 long mask) 757 { 758 struct ak8975_data *data = iio_priv(indio_dev); 759 760 switch (mask) { 761 case IIO_CHAN_INFO_RAW: 762 return ak8975_read_axis(indio_dev, chan->address, val); 763 case IIO_CHAN_INFO_SCALE: 764 *val = 0; 765 *val2 = data->raw_to_gauss[chan->address]; 766 return IIO_VAL_INT_PLUS_MICRO; 767 } 768 return -EINVAL; 769 } 770 771 static const struct iio_mount_matrix * 772 ak8975_get_mount_matrix(const struct iio_dev *indio_dev, 773 const struct iio_chan_spec *chan) 774 { 775 struct ak8975_data *data = iio_priv(indio_dev); 776 777 return &data->orientation; 778 } 779 780 static const struct iio_chan_spec_ext_info ak8975_ext_info[] = { 781 IIO_MOUNT_MATRIX(IIO_SHARED_BY_DIR, ak8975_get_mount_matrix), 782 { } 783 }; 784 785 #define AK8975_CHANNEL(axis, index) \ 786 { \ 787 .type = IIO_MAGN, \ 788 .modified = 1, \ 789 .channel2 = IIO_MOD_##axis, \ 790 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \ 791 BIT(IIO_CHAN_INFO_SCALE), \ 792 .address = index, \ 793 .scan_index = index, \ 794 .scan_type = { \ 795 .sign = 's', \ 796 .realbits = 16, \ 797 .storagebits = 16, \ 798 .endianness = IIO_CPU \ 799 }, \ 800 .ext_info = ak8975_ext_info, \ 801 } 802 803 static const struct iio_chan_spec ak8975_channels[] = { 804 AK8975_CHANNEL(X, 0), AK8975_CHANNEL(Y, 1), AK8975_CHANNEL(Z, 2), 805 IIO_CHAN_SOFT_TIMESTAMP(3), 806 }; 807 808 static const unsigned long ak8975_scan_masks[] = { 0x7, 0 }; 809 810 static const struct iio_info ak8975_info = { 811 .read_raw = &ak8975_read_raw, 812 }; 813 814 static const struct acpi_device_id ak_acpi_match[] = { 815 {"AK8975", AK8975}, 816 {"AK8963", AK8963}, 817 {"INVN6500", AK8963}, 818 {"AK009911", AK09911}, 819 {"AK09911", AK09911}, 820 {"AKM9911", AK09911}, 821 {"AK09912", AK09912}, 822 { } 823 }; 824 MODULE_DEVICE_TABLE(acpi, ak_acpi_match); 825 826 static void ak8975_fill_buffer(struct iio_dev *indio_dev) 827 { 828 struct ak8975_data *data = iio_priv(indio_dev); 829 const struct i2c_client *client = data->client; 830 const struct ak_def *def = data->def; 831 int ret; 832 __le16 fval[3]; 833 834 mutex_lock(&data->lock); 835 836 ret = ak8975_start_read_axis(data, client); 837 if (ret) 838 goto unlock; 839 840 /* 841 * For each axis, read the flux value from the appropriate register 842 * (the register is specified in the iio device attributes). 843 */ 844 ret = i2c_smbus_read_i2c_block_data_or_emulated(client, 845 def->data_regs[0], 846 3 * sizeof(fval[0]), 847 (u8 *)fval); 848 if (ret < 0) 849 goto unlock; 850 851 mutex_unlock(&data->lock); 852 853 /* Clamp to valid range. */ 854 data->scan.channels[0] = clamp_t(s16, le16_to_cpu(fval[0]), -def->range, def->range); 855 data->scan.channels[1] = clamp_t(s16, le16_to_cpu(fval[1]), -def->range, def->range); 856 data->scan.channels[2] = clamp_t(s16, le16_to_cpu(fval[2]), -def->range, def->range); 857 858 iio_push_to_buffers_with_timestamp(indio_dev, &data->scan, 859 iio_get_time_ns(indio_dev)); 860 861 return; 862 863 unlock: 864 mutex_unlock(&data->lock); 865 dev_err(&client->dev, "Error in reading axes block\n"); 866 } 867 868 static irqreturn_t ak8975_handle_trigger(int irq, void *p) 869 { 870 const struct iio_poll_func *pf = p; 871 struct iio_dev *indio_dev = pf->indio_dev; 872 873 ak8975_fill_buffer(indio_dev); 874 iio_trigger_notify_done(indio_dev->trig); 875 return IRQ_HANDLED; 876 } 877 878 static int ak8975_probe(struct i2c_client *client, 879 const struct i2c_device_id *id) 880 { 881 struct ak8975_data *data; 882 struct iio_dev *indio_dev; 883 struct gpio_desc *eoc_gpiod; 884 struct gpio_desc *reset_gpiod; 885 const void *match; 886 unsigned int i; 887 int err; 888 enum asahi_compass_chipset chipset; 889 const char *name = NULL; 890 891 /* 892 * Grab and set up the supplied GPIO. 893 * We may not have a GPIO based IRQ to scan, that is fine, we will 894 * poll if so. 895 */ 896 eoc_gpiod = devm_gpiod_get_optional(&client->dev, NULL, GPIOD_IN); 897 if (IS_ERR(eoc_gpiod)) 898 return PTR_ERR(eoc_gpiod); 899 if (eoc_gpiod) 900 gpiod_set_consumer_name(eoc_gpiod, "ak_8975"); 901 902 /* 903 * According to AK09911 datasheet, if reset GPIO is provided then 904 * deassert reset on ak8975_power_on() and assert reset on 905 * ak8975_power_off(). 906 */ 907 reset_gpiod = devm_gpiod_get_optional(&client->dev, 908 "reset", GPIOD_OUT_HIGH); 909 if (IS_ERR(reset_gpiod)) 910 return PTR_ERR(reset_gpiod); 911 912 /* Register with IIO */ 913 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data)); 914 if (indio_dev == NULL) 915 return -ENOMEM; 916 917 data = iio_priv(indio_dev); 918 i2c_set_clientdata(client, indio_dev); 919 920 data->client = client; 921 data->eoc_gpiod = eoc_gpiod; 922 data->reset_gpiod = reset_gpiod; 923 data->eoc_irq = 0; 924 925 err = iio_read_mount_matrix(&client->dev, &data->orientation); 926 if (err) 927 return err; 928 929 /* id will be NULL when enumerated via ACPI */ 930 match = device_get_match_data(&client->dev); 931 if (match) { 932 chipset = (uintptr_t)match; 933 name = dev_name(&client->dev); 934 } else if (id) { 935 chipset = (enum asahi_compass_chipset)(id->driver_data); 936 name = id->name; 937 } else 938 return -ENOSYS; 939 940 for (i = 0; i < ARRAY_SIZE(ak_def_array); i++) 941 if (ak_def_array[i].type == chipset) 942 break; 943 944 if (i == ARRAY_SIZE(ak_def_array)) { 945 dev_err(&client->dev, "AKM device type unsupported: %d\n", 946 chipset); 947 return -ENODEV; 948 } 949 950 data->def = &ak_def_array[i]; 951 952 /* Fetch the regulators */ 953 data->vdd = devm_regulator_get(&client->dev, "vdd"); 954 if (IS_ERR(data->vdd)) 955 return PTR_ERR(data->vdd); 956 data->vid = devm_regulator_get(&client->dev, "vid"); 957 if (IS_ERR(data->vid)) 958 return PTR_ERR(data->vid); 959 960 err = ak8975_power_on(data); 961 if (err) 962 return err; 963 964 err = ak8975_who_i_am(client, data->def->type); 965 if (err < 0) { 966 dev_err(&client->dev, "Unexpected device\n"); 967 goto power_off; 968 } 969 dev_dbg(&client->dev, "Asahi compass chip %s\n", name); 970 971 /* Perform some basic start-of-day setup of the device. */ 972 err = ak8975_setup(client); 973 if (err < 0) { 974 dev_err(&client->dev, "%s initialization fails\n", name); 975 goto power_off; 976 } 977 978 mutex_init(&data->lock); 979 indio_dev->channels = ak8975_channels; 980 indio_dev->num_channels = ARRAY_SIZE(ak8975_channels); 981 indio_dev->info = &ak8975_info; 982 indio_dev->available_scan_masks = ak8975_scan_masks; 983 indio_dev->modes = INDIO_DIRECT_MODE; 984 indio_dev->name = name; 985 986 err = iio_triggered_buffer_setup(indio_dev, NULL, ak8975_handle_trigger, 987 NULL); 988 if (err) { 989 dev_err(&client->dev, "triggered buffer setup failed\n"); 990 goto power_off; 991 } 992 993 err = iio_device_register(indio_dev); 994 if (err) { 995 dev_err(&client->dev, "device register failed\n"); 996 goto cleanup_buffer; 997 } 998 999 /* Enable runtime PM */ 1000 pm_runtime_get_noresume(&client->dev); 1001 pm_runtime_set_active(&client->dev); 1002 pm_runtime_enable(&client->dev); 1003 /* 1004 * The device comes online in 500us, so add two orders of magnitude 1005 * of delay before autosuspending: 50 ms. 1006 */ 1007 pm_runtime_set_autosuspend_delay(&client->dev, 50); 1008 pm_runtime_use_autosuspend(&client->dev); 1009 pm_runtime_put(&client->dev); 1010 1011 return 0; 1012 1013 cleanup_buffer: 1014 iio_triggered_buffer_cleanup(indio_dev); 1015 power_off: 1016 ak8975_power_off(data); 1017 return err; 1018 } 1019 1020 static int ak8975_remove(struct i2c_client *client) 1021 { 1022 struct iio_dev *indio_dev = i2c_get_clientdata(client); 1023 struct ak8975_data *data = iio_priv(indio_dev); 1024 1025 pm_runtime_get_sync(&client->dev); 1026 pm_runtime_put_noidle(&client->dev); 1027 pm_runtime_disable(&client->dev); 1028 iio_device_unregister(indio_dev); 1029 iio_triggered_buffer_cleanup(indio_dev); 1030 ak8975_set_mode(data, POWER_DOWN); 1031 ak8975_power_off(data); 1032 1033 return 0; 1034 } 1035 1036 #ifdef CONFIG_PM 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 #endif /* CONFIG_PM */ 1078 1079 static const struct dev_pm_ops ak8975_dev_pm_ops = { 1080 SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend, 1081 pm_runtime_force_resume) 1082 SET_RUNTIME_PM_OPS(ak8975_runtime_suspend, 1083 ak8975_runtime_resume, NULL) 1084 }; 1085 1086 static const struct i2c_device_id ak8975_id[] = { 1087 {"ak8975", AK8975}, 1088 {"ak8963", AK8963}, 1089 {"AK8963", AK8963}, 1090 {"ak09911", AK09911}, 1091 {"ak09912", AK09912}, 1092 {"ak09916", AK09916}, 1093 {} 1094 }; 1095 1096 MODULE_DEVICE_TABLE(i2c, ak8975_id); 1097 1098 static const struct of_device_id ak8975_of_match[] = { 1099 { .compatible = "asahi-kasei,ak8975", }, 1100 { .compatible = "ak8975", }, 1101 { .compatible = "asahi-kasei,ak8963", }, 1102 { .compatible = "ak8963", }, 1103 { .compatible = "asahi-kasei,ak09911", }, 1104 { .compatible = "ak09911", }, 1105 { .compatible = "asahi-kasei,ak09912", }, 1106 { .compatible = "ak09912", }, 1107 { .compatible = "asahi-kasei,ak09916", }, 1108 { .compatible = "ak09916", }, 1109 {} 1110 }; 1111 MODULE_DEVICE_TABLE(of, ak8975_of_match); 1112 1113 static struct i2c_driver ak8975_driver = { 1114 .driver = { 1115 .name = "ak8975", 1116 .pm = &ak8975_dev_pm_ops, 1117 .of_match_table = ak8975_of_match, 1118 .acpi_match_table = ak_acpi_match, 1119 }, 1120 .probe = ak8975_probe, 1121 .remove = ak8975_remove, 1122 .id_table = ak8975_id, 1123 }; 1124 module_i2c_driver(ak8975_driver); 1125 1126 MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>"); 1127 MODULE_DESCRIPTION("AK8975 magnetometer driver"); 1128 MODULE_LICENSE("GPL"); 1129