1 /* 2 * A sensor driver for the magnetometer AK8975. 3 * 4 * Magnetic compass sensor driver for monitoring magnetic flux information. 5 * 6 * Copyright (c) 2010, NVIDIA Corporation. 7 * 8 * This program is free software; you can redistribute it and/or modify 9 * it under the terms of the GNU General Public License as published by 10 * the Free Software Foundation; either version 2 of the License, or 11 * (at your option) any later version. 12 * 13 * This program is distributed in the hope that it will be useful, but WITHOUT 14 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 15 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for 16 * more details. 17 * 18 * You should have received a copy of the GNU General Public License along 19 * with this program; if not, write to the Free Software Foundation, Inc., 20 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. 21 */ 22 23 #include <linux/module.h> 24 #include <linux/kernel.h> 25 #include <linux/slab.h> 26 #include <linux/i2c.h> 27 #include <linux/interrupt.h> 28 #include <linux/err.h> 29 #include <linux/mutex.h> 30 #include <linux/delay.h> 31 #include <linux/bitops.h> 32 #include <linux/gpio.h> 33 #include <linux/of_gpio.h> 34 #include <linux/acpi.h> 35 #include <linux/regulator/consumer.h> 36 #include <linux/pm_runtime.h> 37 38 #include <linux/iio/iio.h> 39 #include <linux/iio/sysfs.h> 40 #include <linux/iio/buffer.h> 41 #include <linux/iio/trigger.h> 42 #include <linux/iio/trigger_consumer.h> 43 #include <linux/iio/triggered_buffer.h> 44 45 #include <linux/iio/magnetometer/ak8975.h> 46 47 /* 48 * Register definitions, as well as various shifts and masks to get at the 49 * individual fields of the registers. 50 */ 51 #define AK8975_REG_WIA 0x00 52 #define AK8975_DEVICE_ID 0x48 53 54 #define AK8975_REG_INFO 0x01 55 56 #define AK8975_REG_ST1 0x02 57 #define AK8975_REG_ST1_DRDY_SHIFT 0 58 #define AK8975_REG_ST1_DRDY_MASK (1 << AK8975_REG_ST1_DRDY_SHIFT) 59 60 #define AK8975_REG_HXL 0x03 61 #define AK8975_REG_HXH 0x04 62 #define AK8975_REG_HYL 0x05 63 #define AK8975_REG_HYH 0x06 64 #define AK8975_REG_HZL 0x07 65 #define AK8975_REG_HZH 0x08 66 #define AK8975_REG_ST2 0x09 67 #define AK8975_REG_ST2_DERR_SHIFT 2 68 #define AK8975_REG_ST2_DERR_MASK (1 << AK8975_REG_ST2_DERR_SHIFT) 69 70 #define AK8975_REG_ST2_HOFL_SHIFT 3 71 #define AK8975_REG_ST2_HOFL_MASK (1 << AK8975_REG_ST2_HOFL_SHIFT) 72 73 #define AK8975_REG_CNTL 0x0A 74 #define AK8975_REG_CNTL_MODE_SHIFT 0 75 #define AK8975_REG_CNTL_MODE_MASK (0xF << AK8975_REG_CNTL_MODE_SHIFT) 76 #define AK8975_REG_CNTL_MODE_POWER_DOWN 0x00 77 #define AK8975_REG_CNTL_MODE_ONCE 0x01 78 #define AK8975_REG_CNTL_MODE_SELF_TEST 0x08 79 #define AK8975_REG_CNTL_MODE_FUSE_ROM 0x0F 80 81 #define AK8975_REG_RSVC 0x0B 82 #define AK8975_REG_ASTC 0x0C 83 #define AK8975_REG_TS1 0x0D 84 #define AK8975_REG_TS2 0x0E 85 #define AK8975_REG_I2CDIS 0x0F 86 #define AK8975_REG_ASAX 0x10 87 #define AK8975_REG_ASAY 0x11 88 #define AK8975_REG_ASAZ 0x12 89 90 #define AK8975_MAX_REGS AK8975_REG_ASAZ 91 92 /* 93 * AK09912 Register definitions 94 */ 95 #define AK09912_REG_WIA1 0x00 96 #define AK09912_REG_WIA2 0x01 97 #define AK09912_DEVICE_ID 0x04 98 #define AK09911_DEVICE_ID 0x05 99 100 #define AK09911_REG_INFO1 0x02 101 #define AK09911_REG_INFO2 0x03 102 103 #define AK09912_REG_ST1 0x10 104 105 #define AK09912_REG_ST1_DRDY_SHIFT 0 106 #define AK09912_REG_ST1_DRDY_MASK (1 << AK09912_REG_ST1_DRDY_SHIFT) 107 108 #define AK09912_REG_HXL 0x11 109 #define AK09912_REG_HXH 0x12 110 #define AK09912_REG_HYL 0x13 111 #define AK09912_REG_HYH 0x14 112 #define AK09912_REG_HZL 0x15 113 #define AK09912_REG_HZH 0x16 114 #define AK09912_REG_TMPS 0x17 115 116 #define AK09912_REG_ST2 0x18 117 #define AK09912_REG_ST2_HOFL_SHIFT 3 118 #define AK09912_REG_ST2_HOFL_MASK (1 << AK09912_REG_ST2_HOFL_SHIFT) 119 120 #define AK09912_REG_CNTL1 0x30 121 122 #define AK09912_REG_CNTL2 0x31 123 #define AK09912_REG_CNTL_MODE_POWER_DOWN 0x00 124 #define AK09912_REG_CNTL_MODE_ONCE 0x01 125 #define AK09912_REG_CNTL_MODE_SELF_TEST 0x10 126 #define AK09912_REG_CNTL_MODE_FUSE_ROM 0x1F 127 #define AK09912_REG_CNTL2_MODE_SHIFT 0 128 #define AK09912_REG_CNTL2_MODE_MASK (0x1F << AK09912_REG_CNTL2_MODE_SHIFT) 129 130 #define AK09912_REG_CNTL3 0x32 131 132 #define AK09912_REG_TS1 0x33 133 #define AK09912_REG_TS2 0x34 134 #define AK09912_REG_TS3 0x35 135 #define AK09912_REG_I2CDIS 0x36 136 #define AK09912_REG_TS4 0x37 137 138 #define AK09912_REG_ASAX 0x60 139 #define AK09912_REG_ASAY 0x61 140 #define AK09912_REG_ASAZ 0x62 141 142 #define AK09912_MAX_REGS AK09912_REG_ASAZ 143 144 /* 145 * Miscellaneous values. 146 */ 147 #define AK8975_MAX_CONVERSION_TIMEOUT 500 148 #define AK8975_CONVERSION_DONE_POLL_TIME 10 149 #define AK8975_DATA_READY_TIMEOUT ((100*HZ)/1000) 150 151 /* 152 * Precalculate scale factor (in Gauss units) for each axis and 153 * store in the device data. 154 * 155 * This scale factor is axis-dependent, and is derived from 3 calibration 156 * factors ASA(x), ASA(y), and ASA(z). 157 * 158 * These ASA values are read from the sensor device at start of day, and 159 * cached in the device context struct. 160 * 161 * Adjusting the flux value with the sensitivity adjustment value should be 162 * done via the following formula: 163 * 164 * Hadj = H * ( ( ( (ASA-128)*0.5 ) / 128 ) + 1 ) 165 * where H is the raw value, ASA is the sensitivity adjustment, and Hadj 166 * is the resultant adjusted value. 167 * 168 * We reduce the formula to: 169 * 170 * Hadj = H * (ASA + 128) / 256 171 * 172 * H is in the range of -4096 to 4095. The magnetometer has a range of 173 * +-1229uT. To go from the raw value to uT is: 174 * 175 * HuT = H * 1229/4096, or roughly, 3/10. 176 * 177 * Since 1uT = 0.01 gauss, our final scale factor becomes: 178 * 179 * Hadj = H * ((ASA + 128) / 256) * 3/10 * 1/100 180 * Hadj = H * ((ASA + 128) * 0.003) / 256 181 * 182 * Since ASA doesn't change, we cache the resultant scale factor into the 183 * device context in ak8975_setup(). 184 * 185 * Given we use IIO_VAL_INT_PLUS_MICRO bit when displaying the scale, we 186 * multiply the stored scale value by 1e6. 187 */ 188 static long ak8975_raw_to_gauss(u16 data) 189 { 190 return (((long)data + 128) * 3000) / 256; 191 } 192 193 /* 194 * For AK8963 and AK09911, same calculation, but the device is less sensitive: 195 * 196 * H is in the range of +-8190. The magnetometer has a range of 197 * +-4912uT. To go from the raw value to uT is: 198 * 199 * HuT = H * 4912/8190, or roughly, 6/10, instead of 3/10. 200 */ 201 202 static long ak8963_09911_raw_to_gauss(u16 data) 203 { 204 return (((long)data + 128) * 6000) / 256; 205 } 206 207 /* 208 * For AK09912, same calculation, except the device is more sensitive: 209 * 210 * H is in the range of -32752 to 32752. The magnetometer has a range of 211 * +-4912uT. To go from the raw value to uT is: 212 * 213 * HuT = H * 4912/32752, or roughly, 3/20, instead of 3/10. 214 */ 215 static long ak09912_raw_to_gauss(u16 data) 216 { 217 return (((long)data + 128) * 1500) / 256; 218 } 219 220 /* Compatible Asahi Kasei Compass parts */ 221 enum asahi_compass_chipset { 222 AK8975, 223 AK8963, 224 AK09911, 225 AK09912, 226 AK_MAX_TYPE 227 }; 228 229 enum ak_ctrl_reg_addr { 230 ST1, 231 ST2, 232 CNTL, 233 ASA_BASE, 234 MAX_REGS, 235 REGS_END, 236 }; 237 238 enum ak_ctrl_reg_mask { 239 ST1_DRDY, 240 ST2_HOFL, 241 ST2_DERR, 242 CNTL_MODE, 243 MASK_END, 244 }; 245 246 enum ak_ctrl_mode { 247 POWER_DOWN, 248 MODE_ONCE, 249 SELF_TEST, 250 FUSE_ROM, 251 MODE_END, 252 }; 253 254 struct ak_def { 255 enum asahi_compass_chipset type; 256 long (*raw_to_gauss)(u16 data); 257 u16 range; 258 u8 ctrl_regs[REGS_END]; 259 u8 ctrl_masks[MASK_END]; 260 u8 ctrl_modes[MODE_END]; 261 u8 data_regs[3]; 262 }; 263 264 static const struct ak_def ak_def_array[AK_MAX_TYPE] = { 265 { 266 .type = AK8975, 267 .raw_to_gauss = ak8975_raw_to_gauss, 268 .range = 4096, 269 .ctrl_regs = { 270 AK8975_REG_ST1, 271 AK8975_REG_ST2, 272 AK8975_REG_CNTL, 273 AK8975_REG_ASAX, 274 AK8975_MAX_REGS}, 275 .ctrl_masks = { 276 AK8975_REG_ST1_DRDY_MASK, 277 AK8975_REG_ST2_HOFL_MASK, 278 AK8975_REG_ST2_DERR_MASK, 279 AK8975_REG_CNTL_MODE_MASK}, 280 .ctrl_modes = { 281 AK8975_REG_CNTL_MODE_POWER_DOWN, 282 AK8975_REG_CNTL_MODE_ONCE, 283 AK8975_REG_CNTL_MODE_SELF_TEST, 284 AK8975_REG_CNTL_MODE_FUSE_ROM}, 285 .data_regs = { 286 AK8975_REG_HXL, 287 AK8975_REG_HYL, 288 AK8975_REG_HZL}, 289 }, 290 { 291 .type = AK8963, 292 .raw_to_gauss = ak8963_09911_raw_to_gauss, 293 .range = 8190, 294 .ctrl_regs = { 295 AK8975_REG_ST1, 296 AK8975_REG_ST2, 297 AK8975_REG_CNTL, 298 AK8975_REG_ASAX, 299 AK8975_MAX_REGS}, 300 .ctrl_masks = { 301 AK8975_REG_ST1_DRDY_MASK, 302 AK8975_REG_ST2_HOFL_MASK, 303 0, 304 AK8975_REG_CNTL_MODE_MASK}, 305 .ctrl_modes = { 306 AK8975_REG_CNTL_MODE_POWER_DOWN, 307 AK8975_REG_CNTL_MODE_ONCE, 308 AK8975_REG_CNTL_MODE_SELF_TEST, 309 AK8975_REG_CNTL_MODE_FUSE_ROM}, 310 .data_regs = { 311 AK8975_REG_HXL, 312 AK8975_REG_HYL, 313 AK8975_REG_HZL}, 314 }, 315 { 316 .type = AK09911, 317 .raw_to_gauss = ak8963_09911_raw_to_gauss, 318 .range = 8192, 319 .ctrl_regs = { 320 AK09912_REG_ST1, 321 AK09912_REG_ST2, 322 AK09912_REG_CNTL2, 323 AK09912_REG_ASAX, 324 AK09912_MAX_REGS}, 325 .ctrl_masks = { 326 AK09912_REG_ST1_DRDY_MASK, 327 AK09912_REG_ST2_HOFL_MASK, 328 0, 329 AK09912_REG_CNTL2_MODE_MASK}, 330 .ctrl_modes = { 331 AK09912_REG_CNTL_MODE_POWER_DOWN, 332 AK09912_REG_CNTL_MODE_ONCE, 333 AK09912_REG_CNTL_MODE_SELF_TEST, 334 AK09912_REG_CNTL_MODE_FUSE_ROM}, 335 .data_regs = { 336 AK09912_REG_HXL, 337 AK09912_REG_HYL, 338 AK09912_REG_HZL}, 339 }, 340 { 341 .type = AK09912, 342 .raw_to_gauss = ak09912_raw_to_gauss, 343 .range = 32752, 344 .ctrl_regs = { 345 AK09912_REG_ST1, 346 AK09912_REG_ST2, 347 AK09912_REG_CNTL2, 348 AK09912_REG_ASAX, 349 AK09912_MAX_REGS}, 350 .ctrl_masks = { 351 AK09912_REG_ST1_DRDY_MASK, 352 AK09912_REG_ST2_HOFL_MASK, 353 0, 354 AK09912_REG_CNTL2_MODE_MASK}, 355 .ctrl_modes = { 356 AK09912_REG_CNTL_MODE_POWER_DOWN, 357 AK09912_REG_CNTL_MODE_ONCE, 358 AK09912_REG_CNTL_MODE_SELF_TEST, 359 AK09912_REG_CNTL_MODE_FUSE_ROM}, 360 .data_regs = { 361 AK09912_REG_HXL, 362 AK09912_REG_HYL, 363 AK09912_REG_HZL}, 364 } 365 }; 366 367 /* 368 * Per-instance context data for the device. 369 */ 370 struct ak8975_data { 371 struct i2c_client *client; 372 const struct ak_def *def; 373 struct mutex lock; 374 u8 asa[3]; 375 long raw_to_gauss[3]; 376 int eoc_gpio; 377 int eoc_irq; 378 wait_queue_head_t data_ready_queue; 379 unsigned long flags; 380 u8 cntl_cache; 381 struct iio_mount_matrix orientation; 382 struct regulator *vdd; 383 struct regulator *vid; 384 }; 385 386 /* Enable attached power regulator if any. */ 387 static int ak8975_power_on(const struct ak8975_data *data) 388 { 389 int ret; 390 391 ret = regulator_enable(data->vdd); 392 if (ret) { 393 dev_warn(&data->client->dev, 394 "Failed to enable specified Vdd supply\n"); 395 return ret; 396 } 397 ret = regulator_enable(data->vid); 398 if (ret) { 399 dev_warn(&data->client->dev, 400 "Failed to enable specified Vid supply\n"); 401 return ret; 402 } 403 /* 404 * According to the datasheet the power supply rise time i 200us 405 * and the minimum wait time before mode setting is 100us, in 406 * total 300 us. Add some margin and say minimum 500us here. 407 */ 408 usleep_range(500, 1000); 409 return 0; 410 } 411 412 /* Disable attached power regulator if any. */ 413 static void ak8975_power_off(const struct ak8975_data *data) 414 { 415 regulator_disable(data->vid); 416 regulator_disable(data->vdd); 417 } 418 419 /* 420 * Return 0 if the i2c device is the one we expect. 421 * return a negative error number otherwise 422 */ 423 static int ak8975_who_i_am(struct i2c_client *client, 424 enum asahi_compass_chipset type) 425 { 426 u8 wia_val[2]; 427 int ret; 428 429 /* 430 * Signature for each device: 431 * Device | WIA1 | WIA2 432 * AK09912 | DEVICE_ID | AK09912_DEVICE_ID 433 * AK09911 | DEVICE_ID | AK09911_DEVICE_ID 434 * AK8975 | DEVICE_ID | NA 435 * AK8963 | DEVICE_ID | NA 436 */ 437 ret = i2c_smbus_read_i2c_block_data_or_emulated( 438 client, AK09912_REG_WIA1, 2, wia_val); 439 if (ret < 0) { 440 dev_err(&client->dev, "Error reading WIA\n"); 441 return ret; 442 } 443 444 if (wia_val[0] != AK8975_DEVICE_ID) 445 return -ENODEV; 446 447 switch (type) { 448 case AK8975: 449 case AK8963: 450 return 0; 451 case AK09911: 452 if (wia_val[1] == AK09911_DEVICE_ID) 453 return 0; 454 break; 455 case AK09912: 456 if (wia_val[1] == AK09912_DEVICE_ID) 457 return 0; 458 break; 459 default: 460 dev_err(&client->dev, "Type %d unknown\n", type); 461 } 462 return -ENODEV; 463 } 464 465 /* 466 * Helper function to write to CNTL register. 467 */ 468 static int ak8975_set_mode(struct ak8975_data *data, enum ak_ctrl_mode mode) 469 { 470 u8 regval; 471 int ret; 472 473 regval = (data->cntl_cache & ~data->def->ctrl_masks[CNTL_MODE]) | 474 data->def->ctrl_modes[mode]; 475 ret = i2c_smbus_write_byte_data(data->client, 476 data->def->ctrl_regs[CNTL], regval); 477 if (ret < 0) { 478 return ret; 479 } 480 data->cntl_cache = regval; 481 /* After mode change wait atleast 100us */ 482 usleep_range(100, 500); 483 484 return 0; 485 } 486 487 /* 488 * Handle data ready irq 489 */ 490 static irqreturn_t ak8975_irq_handler(int irq, void *data) 491 { 492 struct ak8975_data *ak8975 = data; 493 494 set_bit(0, &ak8975->flags); 495 wake_up(&ak8975->data_ready_queue); 496 497 return IRQ_HANDLED; 498 } 499 500 /* 501 * Install data ready interrupt handler 502 */ 503 static int ak8975_setup_irq(struct ak8975_data *data) 504 { 505 struct i2c_client *client = data->client; 506 int rc; 507 int irq; 508 509 init_waitqueue_head(&data->data_ready_queue); 510 clear_bit(0, &data->flags); 511 if (client->irq) 512 irq = client->irq; 513 else 514 irq = gpio_to_irq(data->eoc_gpio); 515 516 rc = devm_request_irq(&client->dev, irq, ak8975_irq_handler, 517 IRQF_TRIGGER_RISING | IRQF_ONESHOT, 518 dev_name(&client->dev), data); 519 if (rc < 0) { 520 dev_err(&client->dev, 521 "irq %d request failed, (gpio %d): %d\n", 522 irq, data->eoc_gpio, rc); 523 return rc; 524 } 525 526 data->eoc_irq = irq; 527 528 return rc; 529 } 530 531 532 /* 533 * Perform some start-of-day setup, including reading the asa calibration 534 * values and caching them. 535 */ 536 static int ak8975_setup(struct i2c_client *client) 537 { 538 struct iio_dev *indio_dev = i2c_get_clientdata(client); 539 struct ak8975_data *data = iio_priv(indio_dev); 540 int ret; 541 542 /* Write the fused rom access mode. */ 543 ret = ak8975_set_mode(data, FUSE_ROM); 544 if (ret < 0) { 545 dev_err(&client->dev, "Error in setting fuse access mode\n"); 546 return ret; 547 } 548 549 /* Get asa data and store in the device data. */ 550 ret = i2c_smbus_read_i2c_block_data_or_emulated( 551 client, data->def->ctrl_regs[ASA_BASE], 552 3, data->asa); 553 if (ret < 0) { 554 dev_err(&client->dev, "Not able to read asa data\n"); 555 return ret; 556 } 557 558 /* After reading fuse ROM data set power-down mode */ 559 ret = ak8975_set_mode(data, POWER_DOWN); 560 if (ret < 0) { 561 dev_err(&client->dev, "Error in setting power-down mode\n"); 562 return ret; 563 } 564 565 if (data->eoc_gpio > 0 || client->irq > 0) { 566 ret = ak8975_setup_irq(data); 567 if (ret < 0) { 568 dev_err(&client->dev, 569 "Error setting data ready interrupt\n"); 570 return ret; 571 } 572 } 573 574 data->raw_to_gauss[0] = data->def->raw_to_gauss(data->asa[0]); 575 data->raw_to_gauss[1] = data->def->raw_to_gauss(data->asa[1]); 576 data->raw_to_gauss[2] = data->def->raw_to_gauss(data->asa[2]); 577 578 return 0; 579 } 580 581 static int wait_conversion_complete_gpio(struct ak8975_data *data) 582 { 583 struct i2c_client *client = data->client; 584 u32 timeout_ms = AK8975_MAX_CONVERSION_TIMEOUT; 585 int ret; 586 587 /* Wait for the conversion to complete. */ 588 while (timeout_ms) { 589 msleep(AK8975_CONVERSION_DONE_POLL_TIME); 590 if (gpio_get_value(data->eoc_gpio)) 591 break; 592 timeout_ms -= AK8975_CONVERSION_DONE_POLL_TIME; 593 } 594 if (!timeout_ms) { 595 dev_err(&client->dev, "Conversion timeout happened\n"); 596 return -EINVAL; 597 } 598 599 ret = i2c_smbus_read_byte_data(client, data->def->ctrl_regs[ST1]); 600 if (ret < 0) 601 dev_err(&client->dev, "Error in reading ST1\n"); 602 603 return ret; 604 } 605 606 static int wait_conversion_complete_polled(struct ak8975_data *data) 607 { 608 struct i2c_client *client = data->client; 609 u8 read_status; 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 ret = i2c_smbus_read_byte_data(client, 617 data->def->ctrl_regs[ST1]); 618 if (ret < 0) { 619 dev_err(&client->dev, "Error in reading ST1\n"); 620 return ret; 621 } 622 read_status = ret; 623 if (read_status) 624 break; 625 timeout_ms -= AK8975_CONVERSION_DONE_POLL_TIME; 626 } 627 if (!timeout_ms) { 628 dev_err(&client->dev, "Conversion timeout happened\n"); 629 return -EINVAL; 630 } 631 632 return read_status; 633 } 634 635 /* Returns 0 if the end of conversion interrupt occured or -ETIME otherwise */ 636 static int wait_conversion_complete_interrupt(struct ak8975_data *data) 637 { 638 int ret; 639 640 ret = wait_event_timeout(data->data_ready_queue, 641 test_bit(0, &data->flags), 642 AK8975_DATA_READY_TIMEOUT); 643 clear_bit(0, &data->flags); 644 645 return ret > 0 ? 0 : -ETIME; 646 } 647 648 static int ak8975_start_read_axis(struct ak8975_data *data, 649 const struct i2c_client *client) 650 { 651 /* Set up the device for taking a sample. */ 652 int ret = ak8975_set_mode(data, MODE_ONCE); 653 654 if (ret < 0) { 655 dev_err(&client->dev, "Error in setting operating mode\n"); 656 return ret; 657 } 658 659 /* Wait for the conversion to complete. */ 660 if (data->eoc_irq) 661 ret = wait_conversion_complete_interrupt(data); 662 else if (gpio_is_valid(data->eoc_gpio)) 663 ret = wait_conversion_complete_gpio(data); 664 else 665 ret = wait_conversion_complete_polled(data); 666 if (ret < 0) 667 return ret; 668 669 /* This will be executed only for non-interrupt based waiting case */ 670 if (ret & data->def->ctrl_masks[ST1_DRDY]) { 671 ret = i2c_smbus_read_byte_data(client, 672 data->def->ctrl_regs[ST2]); 673 if (ret < 0) { 674 dev_err(&client->dev, "Error in reading ST2\n"); 675 return ret; 676 } 677 if (ret & (data->def->ctrl_masks[ST2_DERR] | 678 data->def->ctrl_masks[ST2_HOFL])) { 679 dev_err(&client->dev, "ST2 status error 0x%x\n", ret); 680 return -EINVAL; 681 } 682 } 683 684 return 0; 685 } 686 687 /* Retrieve raw flux value for one of the x, y, or z axis. */ 688 static int ak8975_read_axis(struct iio_dev *indio_dev, int index, int *val) 689 { 690 struct ak8975_data *data = iio_priv(indio_dev); 691 const struct i2c_client *client = data->client; 692 const struct ak_def *def = data->def; 693 u16 buff; 694 int ret; 695 696 pm_runtime_get_sync(&data->client->dev); 697 698 mutex_lock(&data->lock); 699 700 ret = ak8975_start_read_axis(data, client); 701 if (ret) 702 goto exit; 703 704 ret = i2c_smbus_read_i2c_block_data_or_emulated( 705 client, def->data_regs[index], 706 sizeof(buff), (u8*)&buff); 707 if (ret < 0) 708 goto exit; 709 710 mutex_unlock(&data->lock); 711 712 pm_runtime_mark_last_busy(&data->client->dev); 713 pm_runtime_put_autosuspend(&data->client->dev); 714 715 /* Swap bytes and convert to valid range. */ 716 buff = le16_to_cpu(buff); 717 *val = clamp_t(s16, buff, -def->range, def->range); 718 return IIO_VAL_INT; 719 720 exit: 721 mutex_unlock(&data->lock); 722 dev_err(&client->dev, "Error in reading axis\n"); 723 return ret; 724 } 725 726 static int ak8975_read_raw(struct iio_dev *indio_dev, 727 struct iio_chan_spec const *chan, 728 int *val, int *val2, 729 long mask) 730 { 731 struct ak8975_data *data = iio_priv(indio_dev); 732 733 switch (mask) { 734 case IIO_CHAN_INFO_RAW: 735 return ak8975_read_axis(indio_dev, chan->address, val); 736 case IIO_CHAN_INFO_SCALE: 737 *val = 0; 738 *val2 = data->raw_to_gauss[chan->address]; 739 return IIO_VAL_INT_PLUS_MICRO; 740 } 741 return -EINVAL; 742 } 743 744 static const struct iio_mount_matrix * 745 ak8975_get_mount_matrix(const struct iio_dev *indio_dev, 746 const struct iio_chan_spec *chan) 747 { 748 return &((struct ak8975_data *)iio_priv(indio_dev))->orientation; 749 } 750 751 static const struct iio_chan_spec_ext_info ak8975_ext_info[] = { 752 IIO_MOUNT_MATRIX(IIO_SHARED_BY_DIR, ak8975_get_mount_matrix), 753 { }, 754 }; 755 756 #define AK8975_CHANNEL(axis, index) \ 757 { \ 758 .type = IIO_MAGN, \ 759 .modified = 1, \ 760 .channel2 = IIO_MOD_##axis, \ 761 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \ 762 BIT(IIO_CHAN_INFO_SCALE), \ 763 .address = index, \ 764 .scan_index = index, \ 765 .scan_type = { \ 766 .sign = 's', \ 767 .realbits = 16, \ 768 .storagebits = 16, \ 769 .endianness = IIO_CPU \ 770 }, \ 771 .ext_info = ak8975_ext_info, \ 772 } 773 774 static const struct iio_chan_spec ak8975_channels[] = { 775 AK8975_CHANNEL(X, 0), AK8975_CHANNEL(Y, 1), AK8975_CHANNEL(Z, 2), 776 IIO_CHAN_SOFT_TIMESTAMP(3), 777 }; 778 779 static const unsigned long ak8975_scan_masks[] = { 0x7, 0 }; 780 781 static const struct iio_info ak8975_info = { 782 .read_raw = &ak8975_read_raw, 783 .driver_module = THIS_MODULE, 784 }; 785 786 static const struct acpi_device_id ak_acpi_match[] = { 787 {"AK8975", AK8975}, 788 {"AK8963", AK8963}, 789 {"INVN6500", AK8963}, 790 {"AK09911", AK09911}, 791 {"AK09912", AK09912}, 792 { }, 793 }; 794 MODULE_DEVICE_TABLE(acpi, ak_acpi_match); 795 796 static const char *ak8975_match_acpi_device(struct device *dev, 797 enum asahi_compass_chipset *chipset) 798 { 799 const struct acpi_device_id *id; 800 801 id = acpi_match_device(dev->driver->acpi_match_table, dev); 802 if (!id) 803 return NULL; 804 *chipset = (int)id->driver_data; 805 806 return dev_name(dev); 807 } 808 809 static void ak8975_fill_buffer(struct iio_dev *indio_dev) 810 { 811 struct ak8975_data *data = iio_priv(indio_dev); 812 const struct i2c_client *client = data->client; 813 const struct ak_def *def = data->def; 814 int ret; 815 s16 buff[8]; /* 3 x 16 bits axis values + 1 aligned 64 bits timestamp */ 816 817 mutex_lock(&data->lock); 818 819 ret = ak8975_start_read_axis(data, client); 820 if (ret) 821 goto unlock; 822 823 /* 824 * For each axis, read the flux value from the appropriate register 825 * (the register is specified in the iio device attributes). 826 */ 827 ret = i2c_smbus_read_i2c_block_data_or_emulated(client, 828 def->data_regs[0], 829 3 * sizeof(buff[0]), 830 (u8 *)buff); 831 if (ret < 0) 832 goto unlock; 833 834 mutex_unlock(&data->lock); 835 836 /* Clamp to valid range. */ 837 buff[0] = clamp_t(s16, le16_to_cpu(buff[0]), -def->range, def->range); 838 buff[1] = clamp_t(s16, le16_to_cpu(buff[1]), -def->range, def->range); 839 buff[2] = clamp_t(s16, le16_to_cpu(buff[2]), -def->range, def->range); 840 841 iio_push_to_buffers_with_timestamp(indio_dev, buff, 842 iio_get_time_ns(indio_dev)); 843 return; 844 845 unlock: 846 mutex_unlock(&data->lock); 847 dev_err(&client->dev, "Error in reading axes block\n"); 848 } 849 850 static irqreturn_t ak8975_handle_trigger(int irq, void *p) 851 { 852 const struct iio_poll_func *pf = p; 853 struct iio_dev *indio_dev = pf->indio_dev; 854 855 ak8975_fill_buffer(indio_dev); 856 iio_trigger_notify_done(indio_dev->trig); 857 return IRQ_HANDLED; 858 } 859 860 static int ak8975_probe(struct i2c_client *client, 861 const struct i2c_device_id *id) 862 { 863 struct ak8975_data *data; 864 struct iio_dev *indio_dev; 865 int eoc_gpio; 866 int err; 867 const char *name = NULL; 868 enum asahi_compass_chipset chipset = AK_MAX_TYPE; 869 const struct ak8975_platform_data *pdata = 870 dev_get_platdata(&client->dev); 871 872 /* Grab and set up the supplied GPIO. */ 873 if (pdata) 874 eoc_gpio = pdata->eoc_gpio; 875 else if (client->dev.of_node) 876 eoc_gpio = of_get_gpio(client->dev.of_node, 0); 877 else 878 eoc_gpio = -1; 879 880 if (eoc_gpio == -EPROBE_DEFER) 881 return -EPROBE_DEFER; 882 883 /* We may not have a GPIO based IRQ to scan, that is fine, we will 884 poll if so */ 885 if (gpio_is_valid(eoc_gpio)) { 886 err = devm_gpio_request_one(&client->dev, eoc_gpio, 887 GPIOF_IN, "ak_8975"); 888 if (err < 0) { 889 dev_err(&client->dev, 890 "failed to request GPIO %d, error %d\n", 891 eoc_gpio, err); 892 return err; 893 } 894 } 895 896 /* Register with IIO */ 897 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data)); 898 if (indio_dev == NULL) 899 return -ENOMEM; 900 901 data = iio_priv(indio_dev); 902 i2c_set_clientdata(client, indio_dev); 903 904 data->client = client; 905 data->eoc_gpio = eoc_gpio; 906 data->eoc_irq = 0; 907 908 if (!pdata) { 909 err = of_iio_read_mount_matrix(&client->dev, 910 "mount-matrix", 911 &data->orientation); 912 if (err) 913 return err; 914 } else 915 data->orientation = pdata->orientation; 916 917 /* id will be NULL when enumerated via ACPI */ 918 if (id) { 919 chipset = (enum asahi_compass_chipset)(id->driver_data); 920 name = id->name; 921 } else if (ACPI_HANDLE(&client->dev)) { 922 name = ak8975_match_acpi_device(&client->dev, &chipset); 923 if (!name) 924 return -ENODEV; 925 } else 926 return -ENOSYS; 927 928 if (chipset >= AK_MAX_TYPE) { 929 dev_err(&client->dev, "AKM device type unsupported: %d\n", 930 chipset); 931 return -ENODEV; 932 } 933 934 data->def = &ak_def_array[chipset]; 935 936 /* Fetch the regulators */ 937 data->vdd = devm_regulator_get(&client->dev, "vdd"); 938 if (IS_ERR(data->vdd)) 939 return PTR_ERR(data->vdd); 940 data->vid = devm_regulator_get(&client->dev, "vid"); 941 if (IS_ERR(data->vid)) 942 return PTR_ERR(data->vid); 943 944 err = ak8975_power_on(data); 945 if (err) 946 return err; 947 948 err = ak8975_who_i_am(client, data->def->type); 949 if (err < 0) { 950 dev_err(&client->dev, "Unexpected device\n"); 951 goto power_off; 952 } 953 dev_dbg(&client->dev, "Asahi compass chip %s\n", name); 954 955 /* Perform some basic start-of-day setup of the device. */ 956 err = ak8975_setup(client); 957 if (err < 0) { 958 dev_err(&client->dev, "%s initialization fails\n", name); 959 goto power_off; 960 } 961 962 mutex_init(&data->lock); 963 indio_dev->dev.parent = &client->dev; 964 indio_dev->channels = ak8975_channels; 965 indio_dev->num_channels = ARRAY_SIZE(ak8975_channels); 966 indio_dev->info = &ak8975_info; 967 indio_dev->available_scan_masks = ak8975_scan_masks; 968 indio_dev->modes = INDIO_DIRECT_MODE; 969 indio_dev->name = name; 970 971 err = iio_triggered_buffer_setup(indio_dev, NULL, ak8975_handle_trigger, 972 NULL); 973 if (err) { 974 dev_err(&client->dev, "triggered buffer setup failed\n"); 975 goto power_off; 976 } 977 978 err = iio_device_register(indio_dev); 979 if (err) { 980 dev_err(&client->dev, "device register failed\n"); 981 goto cleanup_buffer; 982 } 983 984 /* Enable runtime PM */ 985 pm_runtime_get_noresume(&client->dev); 986 pm_runtime_set_active(&client->dev); 987 pm_runtime_enable(&client->dev); 988 /* 989 * The device comes online in 500us, so add two orders of magnitude 990 * of delay before autosuspending: 50 ms. 991 */ 992 pm_runtime_set_autosuspend_delay(&client->dev, 50); 993 pm_runtime_use_autosuspend(&client->dev); 994 pm_runtime_put(&client->dev); 995 996 return 0; 997 998 cleanup_buffer: 999 iio_triggered_buffer_cleanup(indio_dev); 1000 power_off: 1001 ak8975_power_off(data); 1002 return err; 1003 } 1004 1005 static int ak8975_remove(struct i2c_client *client) 1006 { 1007 struct iio_dev *indio_dev = i2c_get_clientdata(client); 1008 struct ak8975_data *data = iio_priv(indio_dev); 1009 1010 pm_runtime_get_sync(&client->dev); 1011 pm_runtime_put_noidle(&client->dev); 1012 pm_runtime_disable(&client->dev); 1013 iio_device_unregister(indio_dev); 1014 iio_triggered_buffer_cleanup(indio_dev); 1015 ak8975_set_mode(data, POWER_DOWN); 1016 ak8975_power_off(data); 1017 1018 return 0; 1019 } 1020 1021 #ifdef CONFIG_PM 1022 static int ak8975_runtime_suspend(struct device *dev) 1023 { 1024 struct i2c_client *client = to_i2c_client(dev); 1025 struct iio_dev *indio_dev = i2c_get_clientdata(client); 1026 struct ak8975_data *data = iio_priv(indio_dev); 1027 int ret; 1028 1029 /* Set the device in power down if it wasn't already */ 1030 ret = ak8975_set_mode(data, POWER_DOWN); 1031 if (ret < 0) { 1032 dev_err(&client->dev, "Error in setting power-down mode\n"); 1033 return ret; 1034 } 1035 /* Next cut the regulators */ 1036 ak8975_power_off(data); 1037 1038 return 0; 1039 } 1040 1041 static int ak8975_runtime_resume(struct device *dev) 1042 { 1043 struct i2c_client *client = to_i2c_client(dev); 1044 struct iio_dev *indio_dev = i2c_get_clientdata(client); 1045 struct ak8975_data *data = iio_priv(indio_dev); 1046 int ret; 1047 1048 /* Take up the regulators */ 1049 ak8975_power_on(data); 1050 /* 1051 * We come up in powered down mode, the reading routines will 1052 * put us in the mode to read values later. 1053 */ 1054 ret = ak8975_set_mode(data, POWER_DOWN); 1055 if (ret < 0) { 1056 dev_err(&client->dev, "Error in setting power-down mode\n"); 1057 return ret; 1058 } 1059 1060 return 0; 1061 } 1062 #endif /* CONFIG_PM */ 1063 1064 static const struct dev_pm_ops ak8975_dev_pm_ops = { 1065 SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend, 1066 pm_runtime_force_resume) 1067 SET_RUNTIME_PM_OPS(ak8975_runtime_suspend, 1068 ak8975_runtime_resume, NULL) 1069 }; 1070 1071 static const struct i2c_device_id ak8975_id[] = { 1072 {"ak8975", AK8975}, 1073 {"ak8963", AK8963}, 1074 {"AK8963", AK8963}, 1075 {"ak09911", AK09911}, 1076 {"ak09912", AK09912}, 1077 {} 1078 }; 1079 1080 MODULE_DEVICE_TABLE(i2c, ak8975_id); 1081 1082 static const struct of_device_id ak8975_of_match[] = { 1083 { .compatible = "asahi-kasei,ak8975", }, 1084 { .compatible = "ak8975", }, 1085 { .compatible = "asahi-kasei,ak8963", }, 1086 { .compatible = "ak8963", }, 1087 { .compatible = "asahi-kasei,ak09911", }, 1088 { .compatible = "ak09911", }, 1089 { .compatible = "asahi-kasei,ak09912", }, 1090 { .compatible = "ak09912", }, 1091 {} 1092 }; 1093 MODULE_DEVICE_TABLE(of, ak8975_of_match); 1094 1095 static struct i2c_driver ak8975_driver = { 1096 .driver = { 1097 .name = "ak8975", 1098 .pm = &ak8975_dev_pm_ops, 1099 .of_match_table = of_match_ptr(ak8975_of_match), 1100 .acpi_match_table = ACPI_PTR(ak_acpi_match), 1101 }, 1102 .probe = ak8975_probe, 1103 .remove = ak8975_remove, 1104 .id_table = ak8975_id, 1105 }; 1106 module_i2c_driver(ak8975_driver); 1107 1108 MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>"); 1109 MODULE_DESCRIPTION("AK8975 magnetometer driver"); 1110 MODULE_LICENSE("GPL"); 1111