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 37 #include <linux/iio/iio.h> 38 #include <linux/iio/sysfs.h> 39 #include <linux/iio/buffer.h> 40 #include <linux/iio/trigger.h> 41 #include <linux/iio/trigger_consumer.h> 42 #include <linux/iio/triggered_buffer.h> 43 44 #include <linux/iio/magnetometer/ak8975.h> 45 46 /* 47 * Register definitions, as well as various shifts and masks to get at the 48 * individual fields of the registers. 49 */ 50 #define AK8975_REG_WIA 0x00 51 #define AK8975_DEVICE_ID 0x48 52 53 #define AK8975_REG_INFO 0x01 54 55 #define AK8975_REG_ST1 0x02 56 #define AK8975_REG_ST1_DRDY_SHIFT 0 57 #define AK8975_REG_ST1_DRDY_MASK (1 << AK8975_REG_ST1_DRDY_SHIFT) 58 59 #define AK8975_REG_HXL 0x03 60 #define AK8975_REG_HXH 0x04 61 #define AK8975_REG_HYL 0x05 62 #define AK8975_REG_HYH 0x06 63 #define AK8975_REG_HZL 0x07 64 #define AK8975_REG_HZH 0x08 65 #define AK8975_REG_ST2 0x09 66 #define AK8975_REG_ST2_DERR_SHIFT 2 67 #define AK8975_REG_ST2_DERR_MASK (1 << AK8975_REG_ST2_DERR_SHIFT) 68 69 #define AK8975_REG_ST2_HOFL_SHIFT 3 70 #define AK8975_REG_ST2_HOFL_MASK (1 << AK8975_REG_ST2_HOFL_SHIFT) 71 72 #define AK8975_REG_CNTL 0x0A 73 #define AK8975_REG_CNTL_MODE_SHIFT 0 74 #define AK8975_REG_CNTL_MODE_MASK (0xF << AK8975_REG_CNTL_MODE_SHIFT) 75 #define AK8975_REG_CNTL_MODE_POWER_DOWN 0x00 76 #define AK8975_REG_CNTL_MODE_ONCE 0x01 77 #define AK8975_REG_CNTL_MODE_SELF_TEST 0x08 78 #define AK8975_REG_CNTL_MODE_FUSE_ROM 0x0F 79 80 #define AK8975_REG_RSVC 0x0B 81 #define AK8975_REG_ASTC 0x0C 82 #define AK8975_REG_TS1 0x0D 83 #define AK8975_REG_TS2 0x0E 84 #define AK8975_REG_I2CDIS 0x0F 85 #define AK8975_REG_ASAX 0x10 86 #define AK8975_REG_ASAY 0x11 87 #define AK8975_REG_ASAZ 0x12 88 89 #define AK8975_MAX_REGS AK8975_REG_ASAZ 90 91 /* 92 * AK09912 Register definitions 93 */ 94 #define AK09912_REG_WIA1 0x00 95 #define AK09912_REG_WIA2 0x01 96 #define AK09912_DEVICE_ID 0x04 97 #define AK09911_DEVICE_ID 0x05 98 99 #define AK09911_REG_INFO1 0x02 100 #define AK09911_REG_INFO2 0x03 101 102 #define AK09912_REG_ST1 0x10 103 104 #define AK09912_REG_ST1_DRDY_SHIFT 0 105 #define AK09912_REG_ST1_DRDY_MASK (1 << AK09912_REG_ST1_DRDY_SHIFT) 106 107 #define AK09912_REG_HXL 0x11 108 #define AK09912_REG_HXH 0x12 109 #define AK09912_REG_HYL 0x13 110 #define AK09912_REG_HYH 0x14 111 #define AK09912_REG_HZL 0x15 112 #define AK09912_REG_HZH 0x16 113 #define AK09912_REG_TMPS 0x17 114 115 #define AK09912_REG_ST2 0x18 116 #define AK09912_REG_ST2_HOFL_SHIFT 3 117 #define AK09912_REG_ST2_HOFL_MASK (1 << AK09912_REG_ST2_HOFL_SHIFT) 118 119 #define AK09912_REG_CNTL1 0x30 120 121 #define AK09912_REG_CNTL2 0x31 122 #define AK09912_REG_CNTL_MODE_POWER_DOWN 0x00 123 #define AK09912_REG_CNTL_MODE_ONCE 0x01 124 #define AK09912_REG_CNTL_MODE_SELF_TEST 0x10 125 #define AK09912_REG_CNTL_MODE_FUSE_ROM 0x1F 126 #define AK09912_REG_CNTL2_MODE_SHIFT 0 127 #define AK09912_REG_CNTL2_MODE_MASK (0x1F << AK09912_REG_CNTL2_MODE_SHIFT) 128 129 #define AK09912_REG_CNTL3 0x32 130 131 #define AK09912_REG_TS1 0x33 132 #define AK09912_REG_TS2 0x34 133 #define AK09912_REG_TS3 0x35 134 #define AK09912_REG_I2CDIS 0x36 135 #define AK09912_REG_TS4 0x37 136 137 #define AK09912_REG_ASAX 0x60 138 #define AK09912_REG_ASAY 0x61 139 #define AK09912_REG_ASAZ 0x62 140 141 #define AK09912_MAX_REGS AK09912_REG_ASAZ 142 143 /* 144 * Miscellaneous values. 145 */ 146 #define AK8975_MAX_CONVERSION_TIMEOUT 500 147 #define AK8975_CONVERSION_DONE_POLL_TIME 10 148 #define AK8975_DATA_READY_TIMEOUT ((100*HZ)/1000) 149 150 /* 151 * Precalculate scale factor (in Gauss units) for each axis and 152 * store in the device data. 153 * 154 * This scale factor is axis-dependent, and is derived from 3 calibration 155 * factors ASA(x), ASA(y), and ASA(z). 156 * 157 * These ASA values are read from the sensor device at start of day, and 158 * cached in the device context struct. 159 * 160 * Adjusting the flux value with the sensitivity adjustment value should be 161 * done via the following formula: 162 * 163 * Hadj = H * ( ( ( (ASA-128)*0.5 ) / 128 ) + 1 ) 164 * where H is the raw value, ASA is the sensitivity adjustment, and Hadj 165 * is the resultant adjusted value. 166 * 167 * We reduce the formula to: 168 * 169 * Hadj = H * (ASA + 128) / 256 170 * 171 * H is in the range of -4096 to 4095. The magnetometer has a range of 172 * +-1229uT. To go from the raw value to uT is: 173 * 174 * HuT = H * 1229/4096, or roughly, 3/10. 175 * 176 * Since 1uT = 0.01 gauss, our final scale factor becomes: 177 * 178 * Hadj = H * ((ASA + 128) / 256) * 3/10 * 1/100 179 * Hadj = H * ((ASA + 128) * 0.003) / 256 180 * 181 * Since ASA doesn't change, we cache the resultant scale factor into the 182 * device context in ak8975_setup(). 183 * 184 * Given we use IIO_VAL_INT_PLUS_MICRO bit when displaying the scale, we 185 * multiply the stored scale value by 1e6. 186 */ 187 static long ak8975_raw_to_gauss(u16 data) 188 { 189 return (((long)data + 128) * 3000) / 256; 190 } 191 192 /* 193 * For AK8963 and AK09911, same calculation, but the device is less sensitive: 194 * 195 * H is in the range of +-8190. The magnetometer has a range of 196 * +-4912uT. To go from the raw value to uT is: 197 * 198 * HuT = H * 4912/8190, or roughly, 6/10, instead of 3/10. 199 */ 200 201 static long ak8963_09911_raw_to_gauss(u16 data) 202 { 203 return (((long)data + 128) * 6000) / 256; 204 } 205 206 /* 207 * For AK09912, same calculation, except the device is more sensitive: 208 * 209 * H is in the range of -32752 to 32752. The magnetometer has a range of 210 * +-4912uT. To go from the raw value to uT is: 211 * 212 * HuT = H * 4912/32752, or roughly, 3/20, instead of 3/10. 213 */ 214 static long ak09912_raw_to_gauss(u16 data) 215 { 216 return (((long)data + 128) * 1500) / 256; 217 } 218 219 /* Compatible Asahi Kasei Compass parts */ 220 enum asahi_compass_chipset { 221 AK8975, 222 AK8963, 223 AK09911, 224 AK09912, 225 AK_MAX_TYPE 226 }; 227 228 enum ak_ctrl_reg_addr { 229 ST1, 230 ST2, 231 CNTL, 232 ASA_BASE, 233 MAX_REGS, 234 REGS_END, 235 }; 236 237 enum ak_ctrl_reg_mask { 238 ST1_DRDY, 239 ST2_HOFL, 240 ST2_DERR, 241 CNTL_MODE, 242 MASK_END, 243 }; 244 245 enum ak_ctrl_mode { 246 POWER_DOWN, 247 MODE_ONCE, 248 SELF_TEST, 249 FUSE_ROM, 250 MODE_END, 251 }; 252 253 struct ak_def { 254 enum asahi_compass_chipset type; 255 long (*raw_to_gauss)(u16 data); 256 u16 range; 257 u8 ctrl_regs[REGS_END]; 258 u8 ctrl_masks[MASK_END]; 259 u8 ctrl_modes[MODE_END]; 260 u8 data_regs[3]; 261 }; 262 263 static const struct ak_def ak_def_array[AK_MAX_TYPE] = { 264 { 265 .type = AK8975, 266 .raw_to_gauss = ak8975_raw_to_gauss, 267 .range = 4096, 268 .ctrl_regs = { 269 AK8975_REG_ST1, 270 AK8975_REG_ST2, 271 AK8975_REG_CNTL, 272 AK8975_REG_ASAX, 273 AK8975_MAX_REGS}, 274 .ctrl_masks = { 275 AK8975_REG_ST1_DRDY_MASK, 276 AK8975_REG_ST2_HOFL_MASK, 277 AK8975_REG_ST2_DERR_MASK, 278 AK8975_REG_CNTL_MODE_MASK}, 279 .ctrl_modes = { 280 AK8975_REG_CNTL_MODE_POWER_DOWN, 281 AK8975_REG_CNTL_MODE_ONCE, 282 AK8975_REG_CNTL_MODE_SELF_TEST, 283 AK8975_REG_CNTL_MODE_FUSE_ROM}, 284 .data_regs = { 285 AK8975_REG_HXL, 286 AK8975_REG_HYL, 287 AK8975_REG_HZL}, 288 }, 289 { 290 .type = AK8963, 291 .raw_to_gauss = ak8963_09911_raw_to_gauss, 292 .range = 8190, 293 .ctrl_regs = { 294 AK8975_REG_ST1, 295 AK8975_REG_ST2, 296 AK8975_REG_CNTL, 297 AK8975_REG_ASAX, 298 AK8975_MAX_REGS}, 299 .ctrl_masks = { 300 AK8975_REG_ST1_DRDY_MASK, 301 AK8975_REG_ST2_HOFL_MASK, 302 0, 303 AK8975_REG_CNTL_MODE_MASK}, 304 .ctrl_modes = { 305 AK8975_REG_CNTL_MODE_POWER_DOWN, 306 AK8975_REG_CNTL_MODE_ONCE, 307 AK8975_REG_CNTL_MODE_SELF_TEST, 308 AK8975_REG_CNTL_MODE_FUSE_ROM}, 309 .data_regs = { 310 AK8975_REG_HXL, 311 AK8975_REG_HYL, 312 AK8975_REG_HZL}, 313 }, 314 { 315 .type = AK09911, 316 .raw_to_gauss = ak8963_09911_raw_to_gauss, 317 .range = 8192, 318 .ctrl_regs = { 319 AK09912_REG_ST1, 320 AK09912_REG_ST2, 321 AK09912_REG_CNTL2, 322 AK09912_REG_ASAX, 323 AK09912_MAX_REGS}, 324 .ctrl_masks = { 325 AK09912_REG_ST1_DRDY_MASK, 326 AK09912_REG_ST2_HOFL_MASK, 327 0, 328 AK09912_REG_CNTL2_MODE_MASK}, 329 .ctrl_modes = { 330 AK09912_REG_CNTL_MODE_POWER_DOWN, 331 AK09912_REG_CNTL_MODE_ONCE, 332 AK09912_REG_CNTL_MODE_SELF_TEST, 333 AK09912_REG_CNTL_MODE_FUSE_ROM}, 334 .data_regs = { 335 AK09912_REG_HXL, 336 AK09912_REG_HYL, 337 AK09912_REG_HZL}, 338 }, 339 { 340 .type = AK09912, 341 .raw_to_gauss = ak09912_raw_to_gauss, 342 .range = 32752, 343 .ctrl_regs = { 344 AK09912_REG_ST1, 345 AK09912_REG_ST2, 346 AK09912_REG_CNTL2, 347 AK09912_REG_ASAX, 348 AK09912_MAX_REGS}, 349 .ctrl_masks = { 350 AK09912_REG_ST1_DRDY_MASK, 351 AK09912_REG_ST2_HOFL_MASK, 352 0, 353 AK09912_REG_CNTL2_MODE_MASK}, 354 .ctrl_modes = { 355 AK09912_REG_CNTL_MODE_POWER_DOWN, 356 AK09912_REG_CNTL_MODE_ONCE, 357 AK09912_REG_CNTL_MODE_SELF_TEST, 358 AK09912_REG_CNTL_MODE_FUSE_ROM}, 359 .data_regs = { 360 AK09912_REG_HXL, 361 AK09912_REG_HYL, 362 AK09912_REG_HZL}, 363 } 364 }; 365 366 /* 367 * Per-instance context data for the device. 368 */ 369 struct ak8975_data { 370 struct i2c_client *client; 371 const struct ak_def *def; 372 struct mutex lock; 373 u8 asa[3]; 374 long raw_to_gauss[3]; 375 int eoc_gpio; 376 int eoc_irq; 377 wait_queue_head_t data_ready_queue; 378 unsigned long flags; 379 u8 cntl_cache; 380 struct iio_mount_matrix orientation; 381 struct regulator *vdd; 382 }; 383 384 /* Enable attached power regulator if any. */ 385 static int ak8975_power_on(struct i2c_client *client) 386 { 387 const struct iio_dev *indio_dev = i2c_get_clientdata(client); 388 struct ak8975_data *data = iio_priv(indio_dev); 389 int ret; 390 391 data->vdd = devm_regulator_get(&client->dev, "vdd"); 392 if (IS_ERR_OR_NULL(data->vdd)) { 393 ret = PTR_ERR(data->vdd); 394 if (ret == -ENODEV) 395 ret = 0; 396 } else { 397 ret = regulator_enable(data->vdd); 398 } 399 400 if (ret) 401 dev_err(&client->dev, "failed to enable Vdd supply: %d\n", ret); 402 return ret; 403 } 404 405 /* Disable attached power regulator if any. */ 406 static void ak8975_power_off(const struct i2c_client *client) 407 { 408 const struct iio_dev *indio_dev = i2c_get_clientdata(client); 409 const struct ak8975_data *data = iio_priv(indio_dev); 410 411 if (!IS_ERR_OR_NULL(data->vdd)) 412 regulator_disable(data->vdd); 413 } 414 415 /* 416 * Return 0 if the i2c device is the one we expect. 417 * return a negative error number otherwise 418 */ 419 static int ak8975_who_i_am(struct i2c_client *client, 420 enum asahi_compass_chipset type) 421 { 422 u8 wia_val[2]; 423 int ret; 424 425 /* 426 * Signature for each device: 427 * Device | WIA1 | WIA2 428 * AK09912 | DEVICE_ID | AK09912_DEVICE_ID 429 * AK09911 | DEVICE_ID | AK09911_DEVICE_ID 430 * AK8975 | DEVICE_ID | NA 431 * AK8963 | DEVICE_ID | NA 432 */ 433 ret = i2c_smbus_read_i2c_block_data(client, AK09912_REG_WIA1, 434 2, wia_val); 435 if (ret < 0) { 436 dev_err(&client->dev, "Error reading WIA\n"); 437 return ret; 438 } 439 440 if (wia_val[0] != AK8975_DEVICE_ID) 441 return -ENODEV; 442 443 switch (type) { 444 case AK8975: 445 case AK8963: 446 return 0; 447 case AK09911: 448 if (wia_val[1] == AK09911_DEVICE_ID) 449 return 0; 450 break; 451 case AK09912: 452 if (wia_val[1] == AK09912_DEVICE_ID) 453 return 0; 454 break; 455 default: 456 dev_err(&client->dev, "Type %d unknown\n", type); 457 } 458 return -ENODEV; 459 } 460 461 /* 462 * Helper function to write to CNTL register. 463 */ 464 static int ak8975_set_mode(struct ak8975_data *data, enum ak_ctrl_mode mode) 465 { 466 u8 regval; 467 int ret; 468 469 regval = (data->cntl_cache & ~data->def->ctrl_masks[CNTL_MODE]) | 470 data->def->ctrl_modes[mode]; 471 ret = i2c_smbus_write_byte_data(data->client, 472 data->def->ctrl_regs[CNTL], regval); 473 if (ret < 0) { 474 return ret; 475 } 476 data->cntl_cache = regval; 477 /* After mode change wait atleast 100us */ 478 usleep_range(100, 500); 479 480 return 0; 481 } 482 483 /* 484 * Handle data ready irq 485 */ 486 static irqreturn_t ak8975_irq_handler(int irq, void *data) 487 { 488 struct ak8975_data *ak8975 = data; 489 490 set_bit(0, &ak8975->flags); 491 wake_up(&ak8975->data_ready_queue); 492 493 return IRQ_HANDLED; 494 } 495 496 /* 497 * Install data ready interrupt handler 498 */ 499 static int ak8975_setup_irq(struct ak8975_data *data) 500 { 501 struct i2c_client *client = data->client; 502 int rc; 503 int irq; 504 505 init_waitqueue_head(&data->data_ready_queue); 506 clear_bit(0, &data->flags); 507 if (client->irq) 508 irq = client->irq; 509 else 510 irq = gpio_to_irq(data->eoc_gpio); 511 512 rc = devm_request_irq(&client->dev, irq, ak8975_irq_handler, 513 IRQF_TRIGGER_RISING | IRQF_ONESHOT, 514 dev_name(&client->dev), data); 515 if (rc < 0) { 516 dev_err(&client->dev, 517 "irq %d request failed, (gpio %d): %d\n", 518 irq, data->eoc_gpio, rc); 519 return rc; 520 } 521 522 data->eoc_irq = irq; 523 524 return rc; 525 } 526 527 528 /* 529 * Perform some start-of-day setup, including reading the asa calibration 530 * values and caching them. 531 */ 532 static int ak8975_setup(struct i2c_client *client) 533 { 534 struct iio_dev *indio_dev = i2c_get_clientdata(client); 535 struct ak8975_data *data = iio_priv(indio_dev); 536 int ret; 537 538 /* Write the fused rom access mode. */ 539 ret = ak8975_set_mode(data, FUSE_ROM); 540 if (ret < 0) { 541 dev_err(&client->dev, "Error in setting fuse access mode\n"); 542 return ret; 543 } 544 545 /* Get asa data and store in the device data. */ 546 ret = i2c_smbus_read_i2c_block_data(client, 547 data->def->ctrl_regs[ASA_BASE], 548 3, data->asa); 549 if (ret < 0) { 550 dev_err(&client->dev, "Not able to read asa data\n"); 551 return ret; 552 } 553 554 /* After reading fuse ROM data set power-down mode */ 555 ret = ak8975_set_mode(data, POWER_DOWN); 556 if (ret < 0) { 557 dev_err(&client->dev, "Error in setting power-down mode\n"); 558 return ret; 559 } 560 561 if (data->eoc_gpio > 0 || client->irq > 0) { 562 ret = ak8975_setup_irq(data); 563 if (ret < 0) { 564 dev_err(&client->dev, 565 "Error setting data ready interrupt\n"); 566 return ret; 567 } 568 } 569 570 data->raw_to_gauss[0] = data->def->raw_to_gauss(data->asa[0]); 571 data->raw_to_gauss[1] = data->def->raw_to_gauss(data->asa[1]); 572 data->raw_to_gauss[2] = data->def->raw_to_gauss(data->asa[2]); 573 574 return 0; 575 } 576 577 static int wait_conversion_complete_gpio(struct ak8975_data *data) 578 { 579 struct i2c_client *client = data->client; 580 u32 timeout_ms = AK8975_MAX_CONVERSION_TIMEOUT; 581 int ret; 582 583 /* Wait for the conversion to complete. */ 584 while (timeout_ms) { 585 msleep(AK8975_CONVERSION_DONE_POLL_TIME); 586 if (gpio_get_value(data->eoc_gpio)) 587 break; 588 timeout_ms -= AK8975_CONVERSION_DONE_POLL_TIME; 589 } 590 if (!timeout_ms) { 591 dev_err(&client->dev, "Conversion timeout happened\n"); 592 return -EINVAL; 593 } 594 595 ret = i2c_smbus_read_byte_data(client, data->def->ctrl_regs[ST1]); 596 if (ret < 0) 597 dev_err(&client->dev, "Error in reading ST1\n"); 598 599 return ret; 600 } 601 602 static int wait_conversion_complete_polled(struct ak8975_data *data) 603 { 604 struct i2c_client *client = data->client; 605 u8 read_status; 606 u32 timeout_ms = AK8975_MAX_CONVERSION_TIMEOUT; 607 int ret; 608 609 /* Wait for the conversion to complete. */ 610 while (timeout_ms) { 611 msleep(AK8975_CONVERSION_DONE_POLL_TIME); 612 ret = i2c_smbus_read_byte_data(client, 613 data->def->ctrl_regs[ST1]); 614 if (ret < 0) { 615 dev_err(&client->dev, "Error in reading ST1\n"); 616 return ret; 617 } 618 read_status = ret; 619 if (read_status) 620 break; 621 timeout_ms -= AK8975_CONVERSION_DONE_POLL_TIME; 622 } 623 if (!timeout_ms) { 624 dev_err(&client->dev, "Conversion timeout happened\n"); 625 return -EINVAL; 626 } 627 628 return read_status; 629 } 630 631 /* Returns 0 if the end of conversion interrupt occured or -ETIME otherwise */ 632 static int wait_conversion_complete_interrupt(struct ak8975_data *data) 633 { 634 int ret; 635 636 ret = wait_event_timeout(data->data_ready_queue, 637 test_bit(0, &data->flags), 638 AK8975_DATA_READY_TIMEOUT); 639 clear_bit(0, &data->flags); 640 641 return ret > 0 ? 0 : -ETIME; 642 } 643 644 static int ak8975_start_read_axis(struct ak8975_data *data, 645 const struct i2c_client *client) 646 { 647 /* Set up the device for taking a sample. */ 648 int ret = ak8975_set_mode(data, MODE_ONCE); 649 650 if (ret < 0) { 651 dev_err(&client->dev, "Error in setting operating mode\n"); 652 return ret; 653 } 654 655 /* Wait for the conversion to complete. */ 656 if (data->eoc_irq) 657 ret = wait_conversion_complete_interrupt(data); 658 else if (gpio_is_valid(data->eoc_gpio)) 659 ret = wait_conversion_complete_gpio(data); 660 else 661 ret = wait_conversion_complete_polled(data); 662 if (ret < 0) 663 return ret; 664 665 /* This will be executed only for non-interrupt based waiting case */ 666 if (ret & data->def->ctrl_masks[ST1_DRDY]) { 667 ret = i2c_smbus_read_byte_data(client, 668 data->def->ctrl_regs[ST2]); 669 if (ret < 0) { 670 dev_err(&client->dev, "Error in reading ST2\n"); 671 return ret; 672 } 673 if (ret & (data->def->ctrl_masks[ST2_DERR] | 674 data->def->ctrl_masks[ST2_HOFL])) { 675 dev_err(&client->dev, "ST2 status error 0x%x\n", ret); 676 return -EINVAL; 677 } 678 } 679 680 return 0; 681 } 682 683 /* Retrieve raw flux value for one of the x, y, or z axis. */ 684 static int ak8975_read_axis(struct iio_dev *indio_dev, int index, int *val) 685 { 686 struct ak8975_data *data = iio_priv(indio_dev); 687 const struct i2c_client *client = data->client; 688 const struct ak_def *def = data->def; 689 int ret; 690 691 mutex_lock(&data->lock); 692 693 ret = ak8975_start_read_axis(data, client); 694 if (ret) 695 goto exit; 696 697 ret = i2c_smbus_read_word_data(client, def->data_regs[index]); 698 if (ret < 0) 699 goto exit; 700 701 mutex_unlock(&data->lock); 702 703 /* Clamp to valid range. */ 704 *val = clamp_t(s16, ret, -def->range, def->range); 705 return IIO_VAL_INT; 706 707 exit: 708 mutex_unlock(&data->lock); 709 dev_err(&client->dev, "Error in reading axis\n"); 710 return ret; 711 } 712 713 static int ak8975_read_raw(struct iio_dev *indio_dev, 714 struct iio_chan_spec const *chan, 715 int *val, int *val2, 716 long mask) 717 { 718 struct ak8975_data *data = iio_priv(indio_dev); 719 720 switch (mask) { 721 case IIO_CHAN_INFO_RAW: 722 return ak8975_read_axis(indio_dev, chan->address, val); 723 case IIO_CHAN_INFO_SCALE: 724 *val = 0; 725 *val2 = data->raw_to_gauss[chan->address]; 726 return IIO_VAL_INT_PLUS_MICRO; 727 } 728 return -EINVAL; 729 } 730 731 static const struct iio_mount_matrix * 732 ak8975_get_mount_matrix(const struct iio_dev *indio_dev, 733 const struct iio_chan_spec *chan) 734 { 735 return &((struct ak8975_data *)iio_priv(indio_dev))->orientation; 736 } 737 738 static const struct iio_chan_spec_ext_info ak8975_ext_info[] = { 739 IIO_MOUNT_MATRIX(IIO_SHARED_BY_DIR, ak8975_get_mount_matrix), 740 { }, 741 }; 742 743 #define AK8975_CHANNEL(axis, index) \ 744 { \ 745 .type = IIO_MAGN, \ 746 .modified = 1, \ 747 .channel2 = IIO_MOD_##axis, \ 748 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \ 749 BIT(IIO_CHAN_INFO_SCALE), \ 750 .address = index, \ 751 .scan_index = index, \ 752 .scan_type = { \ 753 .sign = 's', \ 754 .realbits = 16, \ 755 .storagebits = 16, \ 756 .endianness = IIO_CPU \ 757 }, \ 758 .ext_info = ak8975_ext_info, \ 759 } 760 761 static const struct iio_chan_spec ak8975_channels[] = { 762 AK8975_CHANNEL(X, 0), AK8975_CHANNEL(Y, 1), AK8975_CHANNEL(Z, 2), 763 IIO_CHAN_SOFT_TIMESTAMP(3), 764 }; 765 766 static const unsigned long ak8975_scan_masks[] = { 0x7, 0 }; 767 768 static const struct iio_info ak8975_info = { 769 .read_raw = &ak8975_read_raw, 770 .driver_module = THIS_MODULE, 771 }; 772 773 static const struct acpi_device_id ak_acpi_match[] = { 774 {"AK8975", AK8975}, 775 {"AK8963", AK8963}, 776 {"INVN6500", AK8963}, 777 {"AK09911", AK09911}, 778 {"AK09912", AK09912}, 779 { }, 780 }; 781 MODULE_DEVICE_TABLE(acpi, ak_acpi_match); 782 783 static const char *ak8975_match_acpi_device(struct device *dev, 784 enum asahi_compass_chipset *chipset) 785 { 786 const struct acpi_device_id *id; 787 788 id = acpi_match_device(dev->driver->acpi_match_table, dev); 789 if (!id) 790 return NULL; 791 *chipset = (int)id->driver_data; 792 793 return dev_name(dev); 794 } 795 796 static void ak8975_fill_buffer(struct iio_dev *indio_dev) 797 { 798 struct ak8975_data *data = iio_priv(indio_dev); 799 const struct i2c_client *client = data->client; 800 const struct ak_def *def = data->def; 801 int ret; 802 s16 buff[8]; /* 3 x 16 bits axis values + 1 aligned 64 bits timestamp */ 803 804 mutex_lock(&data->lock); 805 806 ret = ak8975_start_read_axis(data, client); 807 if (ret) 808 goto unlock; 809 810 /* 811 * For each axis, read the flux value from the appropriate register 812 * (the register is specified in the iio device attributes). 813 */ 814 ret = i2c_smbus_read_i2c_block_data_or_emulated(client, 815 def->data_regs[0], 816 3 * sizeof(buff[0]), 817 (u8 *)buff); 818 if (ret < 0) 819 goto unlock; 820 821 mutex_unlock(&data->lock); 822 823 /* Clamp to valid range. */ 824 buff[0] = clamp_t(s16, le16_to_cpu(buff[0]), -def->range, def->range); 825 buff[1] = clamp_t(s16, le16_to_cpu(buff[1]), -def->range, def->range); 826 buff[2] = clamp_t(s16, le16_to_cpu(buff[2]), -def->range, def->range); 827 828 iio_push_to_buffers_with_timestamp(indio_dev, buff, iio_get_time_ns()); 829 return; 830 831 unlock: 832 mutex_unlock(&data->lock); 833 dev_err(&client->dev, "Error in reading axes block\n"); 834 } 835 836 static irqreturn_t ak8975_handle_trigger(int irq, void *p) 837 { 838 const struct iio_poll_func *pf = p; 839 struct iio_dev *indio_dev = pf->indio_dev; 840 841 ak8975_fill_buffer(indio_dev); 842 iio_trigger_notify_done(indio_dev->trig); 843 return IRQ_HANDLED; 844 } 845 846 static int ak8975_probe(struct i2c_client *client, 847 const struct i2c_device_id *id) 848 { 849 struct ak8975_data *data; 850 struct iio_dev *indio_dev; 851 int eoc_gpio; 852 int err; 853 const char *name = NULL; 854 enum asahi_compass_chipset chipset = AK_MAX_TYPE; 855 const struct ak8975_platform_data *pdata = 856 dev_get_platdata(&client->dev); 857 858 /* Grab and set up the supplied GPIO. */ 859 if (pdata) 860 eoc_gpio = pdata->eoc_gpio; 861 else if (client->dev.of_node) 862 eoc_gpio = of_get_gpio(client->dev.of_node, 0); 863 else 864 eoc_gpio = -1; 865 866 if (eoc_gpio == -EPROBE_DEFER) 867 return -EPROBE_DEFER; 868 869 /* We may not have a GPIO based IRQ to scan, that is fine, we will 870 poll if so */ 871 if (gpio_is_valid(eoc_gpio)) { 872 err = devm_gpio_request_one(&client->dev, eoc_gpio, 873 GPIOF_IN, "ak_8975"); 874 if (err < 0) { 875 dev_err(&client->dev, 876 "failed to request GPIO %d, error %d\n", 877 eoc_gpio, err); 878 return err; 879 } 880 } 881 882 /* Register with IIO */ 883 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data)); 884 if (indio_dev == NULL) 885 return -ENOMEM; 886 887 data = iio_priv(indio_dev); 888 i2c_set_clientdata(client, indio_dev); 889 890 data->client = client; 891 data->eoc_gpio = eoc_gpio; 892 data->eoc_irq = 0; 893 894 if (!pdata) { 895 err = of_iio_read_mount_matrix(&client->dev, 896 "mount-matrix", 897 &data->orientation); 898 if (err) 899 return err; 900 } else 901 data->orientation = pdata->orientation; 902 903 /* id will be NULL when enumerated via ACPI */ 904 if (id) { 905 chipset = (enum asahi_compass_chipset)(id->driver_data); 906 name = id->name; 907 } else if (ACPI_HANDLE(&client->dev)) { 908 name = ak8975_match_acpi_device(&client->dev, &chipset); 909 if (!name) 910 return -ENODEV; 911 } else 912 return -ENOSYS; 913 914 if (chipset >= AK_MAX_TYPE) { 915 dev_err(&client->dev, "AKM device type unsupported: %d\n", 916 chipset); 917 return -ENODEV; 918 } 919 920 data->def = &ak_def_array[chipset]; 921 922 err = ak8975_power_on(client); 923 if (err) 924 return err; 925 926 err = ak8975_who_i_am(client, data->def->type); 927 if (err < 0) { 928 dev_err(&client->dev, "Unexpected device\n"); 929 goto power_off; 930 } 931 dev_dbg(&client->dev, "Asahi compass chip %s\n", name); 932 933 /* Perform some basic start-of-day setup of the device. */ 934 err = ak8975_setup(client); 935 if (err < 0) { 936 dev_err(&client->dev, "%s initialization fails\n", name); 937 goto power_off; 938 } 939 940 mutex_init(&data->lock); 941 indio_dev->dev.parent = &client->dev; 942 indio_dev->channels = ak8975_channels; 943 indio_dev->num_channels = ARRAY_SIZE(ak8975_channels); 944 indio_dev->info = &ak8975_info; 945 indio_dev->available_scan_masks = ak8975_scan_masks; 946 indio_dev->modes = INDIO_DIRECT_MODE; 947 indio_dev->name = name; 948 949 err = iio_triggered_buffer_setup(indio_dev, NULL, ak8975_handle_trigger, 950 NULL); 951 if (err) { 952 dev_err(&client->dev, "triggered buffer setup failed\n"); 953 goto power_off; 954 } 955 956 err = iio_device_register(indio_dev); 957 if (err) { 958 dev_err(&client->dev, "device register failed\n"); 959 goto cleanup_buffer; 960 } 961 962 return 0; 963 964 cleanup_buffer: 965 iio_triggered_buffer_cleanup(indio_dev); 966 power_off: 967 ak8975_power_off(client); 968 return err; 969 } 970 971 static int ak8975_remove(struct i2c_client *client) 972 { 973 struct iio_dev *indio_dev = i2c_get_clientdata(client); 974 975 iio_device_unregister(indio_dev); 976 iio_triggered_buffer_cleanup(indio_dev); 977 ak8975_power_off(client); 978 979 return 0; 980 } 981 982 static const struct i2c_device_id ak8975_id[] = { 983 {"ak8975", AK8975}, 984 {"ak8963", AK8963}, 985 {"AK8963", AK8963}, 986 {"ak09911", AK09911}, 987 {"ak09912", AK09912}, 988 {} 989 }; 990 991 MODULE_DEVICE_TABLE(i2c, ak8975_id); 992 993 static const struct of_device_id ak8975_of_match[] = { 994 { .compatible = "asahi-kasei,ak8975", }, 995 { .compatible = "ak8975", }, 996 { .compatible = "asahi-kasei,ak8963", }, 997 { .compatible = "ak8963", }, 998 { .compatible = "asahi-kasei,ak09911", }, 999 { .compatible = "ak09911", }, 1000 { .compatible = "asahi-kasei,ak09912", }, 1001 { .compatible = "ak09912", }, 1002 {} 1003 }; 1004 MODULE_DEVICE_TABLE(of, ak8975_of_match); 1005 1006 static struct i2c_driver ak8975_driver = { 1007 .driver = { 1008 .name = "ak8975", 1009 .of_match_table = of_match_ptr(ak8975_of_match), 1010 .acpi_match_table = ACPI_PTR(ak_acpi_match), 1011 }, 1012 .probe = ak8975_probe, 1013 .remove = ak8975_remove, 1014 .id_table = ak8975_id, 1015 }; 1016 module_i2c_driver(ak8975_driver); 1017 1018 MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>"); 1019 MODULE_DESCRIPTION("AK8975 magnetometer driver"); 1020 MODULE_LICENSE("GPL"); 1021