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1// SPDX-License-Identifier: GPL-2.0-or-later2/*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 the33 * individual fields of the registers.34 */35#define AK8975_REG_WIA 0x0036#define AK8975_DEVICE_ID 0x4837 38#define AK8975_REG_INFO 0x0139 40#define AK8975_REG_ST1 0x0241#define AK8975_REG_ST1_DRDY_SHIFT 042#define AK8975_REG_ST1_DRDY_MASK (1 << AK8975_REG_ST1_DRDY_SHIFT)43 44#define AK8975_REG_HXL 0x0345#define AK8975_REG_HXH 0x0446#define AK8975_REG_HYL 0x0547#define AK8975_REG_HYH 0x0648#define AK8975_REG_HZL 0x0749#define AK8975_REG_HZH 0x0850#define AK8975_REG_ST2 0x0951#define AK8975_REG_ST2_DERR_SHIFT 252#define AK8975_REG_ST2_DERR_MASK (1 << AK8975_REG_ST2_DERR_SHIFT)53 54#define AK8975_REG_ST2_HOFL_SHIFT 355#define AK8975_REG_ST2_HOFL_MASK (1 << AK8975_REG_ST2_HOFL_SHIFT)56 57#define AK8975_REG_CNTL 0x0A58#define AK8975_REG_CNTL_MODE_SHIFT 059#define AK8975_REG_CNTL_MODE_MASK (0xF << AK8975_REG_CNTL_MODE_SHIFT)60#define AK8975_REG_CNTL_MODE_POWER_DOWN 0x0061#define AK8975_REG_CNTL_MODE_ONCE 0x0162#define AK8975_REG_CNTL_MODE_SELF_TEST 0x0863#define AK8975_REG_CNTL_MODE_FUSE_ROM 0x0F64 65#define AK8975_REG_RSVC 0x0B66#define AK8975_REG_ASTC 0x0C67#define AK8975_REG_TS1 0x0D68#define AK8975_REG_TS2 0x0E69#define AK8975_REG_I2CDIS 0x0F70#define AK8975_REG_ASAX 0x1071#define AK8975_REG_ASAY 0x1172#define AK8975_REG_ASAZ 0x1273 74#define AK8975_MAX_REGS AK8975_REG_ASAZ75 76/*77 * AK09912 Register definitions78 */79#define AK09912_REG_WIA1 0x0080#define AK09912_REG_WIA2 0x0181#define AK09918_DEVICE_ID 0x0C82#define AK09916_DEVICE_ID 0x0983#define AK09912_DEVICE_ID 0x0484#define AK09911_DEVICE_ID 0x0585 86#define AK09911_REG_INFO1 0x0287#define AK09911_REG_INFO2 0x0388 89#define AK09912_REG_ST1 0x1090 91#define AK09912_REG_ST1_DRDY_SHIFT 092#define AK09912_REG_ST1_DRDY_MASK (1 << AK09912_REG_ST1_DRDY_SHIFT)93 94#define AK09912_REG_HXL 0x1195#define AK09912_REG_HXH 0x1296#define AK09912_REG_HYL 0x1397#define AK09912_REG_HYH 0x1498#define AK09912_REG_HZL 0x1599#define AK09912_REG_HZH 0x16100#define AK09912_REG_TMPS 0x17101 102#define AK09912_REG_ST2 0x18103#define AK09912_REG_ST2_HOFL_SHIFT 3104#define AK09912_REG_ST2_HOFL_MASK (1 << AK09912_REG_ST2_HOFL_SHIFT)105 106#define AK09912_REG_CNTL1 0x30107 108#define AK09912_REG_CNTL2 0x31109#define AK09912_REG_CNTL_MODE_POWER_DOWN 0x00110#define AK09912_REG_CNTL_MODE_ONCE 0x01111#define AK09912_REG_CNTL_MODE_SELF_TEST 0x10112#define AK09912_REG_CNTL_MODE_FUSE_ROM 0x1F113#define AK09912_REG_CNTL2_MODE_SHIFT 0114#define AK09912_REG_CNTL2_MODE_MASK (0x1F << AK09912_REG_CNTL2_MODE_SHIFT)115 116#define AK09912_REG_CNTL3 0x32117 118#define AK09912_REG_TS1 0x33119#define AK09912_REG_TS2 0x34120#define AK09912_REG_TS3 0x35121#define AK09912_REG_I2CDIS 0x36122#define AK09912_REG_TS4 0x37123 124#define AK09912_REG_ASAX 0x60125#define AK09912_REG_ASAY 0x61126#define AK09912_REG_ASAZ 0x62127 128#define AK09912_MAX_REGS AK09912_REG_ASAZ129 130/*131 * Miscellaneous values.132 */133#define AK8975_MAX_CONVERSION_TIMEOUT 500134#define AK8975_CONVERSION_DONE_POLL_TIME 10135#define AK8975_DATA_READY_TIMEOUT ((100*HZ)/1000)136 137/*138 * Precalculate scale factor (in Gauss units) for each axis and139 * store in the device data.140 *141 * This scale factor is axis-dependent, and is derived from 3 calibration142 * factors ASA(x), ASA(y), and ASA(z).143 *144 * These ASA values are read from the sensor device at start of day, and145 * cached in the device context struct.146 *147 * Adjusting the flux value with the sensitivity adjustment value should be148 * done via the following formula:149 *150 * Hadj = H * ( ( ( (ASA-128)*0.5 ) / 128 ) + 1 )151 * where H is the raw value, ASA is the sensitivity adjustment, and Hadj152 * is the resultant adjusted value.153 *154 * We reduce the formula to:155 *156 * Hadj = H * (ASA + 128) / 256157 *158 * H is in the range of -4096 to 4095. The magnetometer has a range of159 * +-1229uT. To go from the raw value to uT is:160 *161 * HuT = H * 1229/4096, or roughly, 3/10.162 *163 * Since 1uT = 0.01 gauss, our final scale factor becomes:164 *165 * Hadj = H * ((ASA + 128) / 256) * 3/10 * 1/100166 * Hadj = H * ((ASA + 128) * 0.003) / 256167 *168 * Since ASA doesn't change, we cache the resultant scale factor into the169 * device context in ak8975_setup().170 *171 * Given we use IIO_VAL_INT_PLUS_MICRO bit when displaying the scale, we172 * multiply the stored scale value by 1e6.173 */174static long ak8975_raw_to_gauss(u16 data)175{176 return (((long)data + 128) * 3000) / 256;177}178 179/*180 * For AK8963 and AK09911, same calculation, but the device is less sensitive:181 *182 * H is in the range of +-8190. The magnetometer has a range of183 * +-4912uT. To go from the raw value to uT is:184 *185 * HuT = H * 4912/8190, or roughly, 6/10, instead of 3/10.186 */187 188static long ak8963_09911_raw_to_gauss(u16 data)189{190 return (((long)data + 128) * 6000) / 256;191}192 193/*194 * For AK09912, same calculation, except the device is more sensitive:195 *196 * H is in the range of -32752 to 32752. The magnetometer has a range of197 * +-4912uT. To go from the raw value to uT is:198 *199 * HuT = H * 4912/32752, or roughly, 3/20, instead of 3/10.200 */201static long ak09912_raw_to_gauss(u16 data)202{203 return (((long)data + 128) * 1500) / 256;204}205 206/* Compatible Asahi Kasei Compass parts */207enum asahi_compass_chipset {208 AK8975,209 AK8963,210 AK09911,211 AK09912,212 AK09916,213 AK09918,214};215 216enum ak_ctrl_reg_addr {217 ST1,218 ST2,219 CNTL,220 ASA_BASE,221 MAX_REGS,222 REGS_END,223};224 225enum ak_ctrl_reg_mask {226 ST1_DRDY,227 ST2_HOFL,228 ST2_DERR,229 CNTL_MODE,230 MASK_END,231};232 233enum ak_ctrl_mode {234 POWER_DOWN,235 MODE_ONCE,236 SELF_TEST,237 FUSE_ROM,238 MODE_END,239};240 241struct ak_def {242 enum asahi_compass_chipset type;243 long (*raw_to_gauss)(u16 data);244 u16 range;245 u8 ctrl_regs[REGS_END];246 u8 ctrl_masks[MASK_END];247 u8 ctrl_modes[MODE_END];248 u8 data_regs[3];249};250 251static const struct ak_def ak_def_array[] = {252 [AK8975] = {253 .type = AK8975,254 .raw_to_gauss = ak8975_raw_to_gauss,255 .range = 4096,256 .ctrl_regs = {257 AK8975_REG_ST1,258 AK8975_REG_ST2,259 AK8975_REG_CNTL,260 AK8975_REG_ASAX,261 AK8975_MAX_REGS},262 .ctrl_masks = {263 AK8975_REG_ST1_DRDY_MASK,264 AK8975_REG_ST2_HOFL_MASK,265 AK8975_REG_ST2_DERR_MASK,266 AK8975_REG_CNTL_MODE_MASK},267 .ctrl_modes = {268 AK8975_REG_CNTL_MODE_POWER_DOWN,269 AK8975_REG_CNTL_MODE_ONCE,270 AK8975_REG_CNTL_MODE_SELF_TEST,271 AK8975_REG_CNTL_MODE_FUSE_ROM},272 .data_regs = {273 AK8975_REG_HXL,274 AK8975_REG_HYL,275 AK8975_REG_HZL},276 },277 [AK8963] = {278 .type = AK8963,279 .raw_to_gauss = ak8963_09911_raw_to_gauss,280 .range = 8190,281 .ctrl_regs = {282 AK8975_REG_ST1,283 AK8975_REG_ST2,284 AK8975_REG_CNTL,285 AK8975_REG_ASAX,286 AK8975_MAX_REGS},287 .ctrl_masks = {288 AK8975_REG_ST1_DRDY_MASK,289 AK8975_REG_ST2_HOFL_MASK,290 0,291 AK8975_REG_CNTL_MODE_MASK},292 .ctrl_modes = {293 AK8975_REG_CNTL_MODE_POWER_DOWN,294 AK8975_REG_CNTL_MODE_ONCE,295 AK8975_REG_CNTL_MODE_SELF_TEST,296 AK8975_REG_CNTL_MODE_FUSE_ROM},297 .data_regs = {298 AK8975_REG_HXL,299 AK8975_REG_HYL,300 AK8975_REG_HZL},301 },302 [AK09911] = {303 .type = AK09911,304 .raw_to_gauss = ak8963_09911_raw_to_gauss,305 .range = 8192,306 .ctrl_regs = {307 AK09912_REG_ST1,308 AK09912_REG_ST2,309 AK09912_REG_CNTL2,310 AK09912_REG_ASAX,311 AK09912_MAX_REGS},312 .ctrl_masks = {313 AK09912_REG_ST1_DRDY_MASK,314 AK09912_REG_ST2_HOFL_MASK,315 0,316 AK09912_REG_CNTL2_MODE_MASK},317 .ctrl_modes = {318 AK09912_REG_CNTL_MODE_POWER_DOWN,319 AK09912_REG_CNTL_MODE_ONCE,320 AK09912_REG_CNTL_MODE_SELF_TEST,321 AK09912_REG_CNTL_MODE_FUSE_ROM},322 .data_regs = {323 AK09912_REG_HXL,324 AK09912_REG_HYL,325 AK09912_REG_HZL},326 },327 [AK09912] = {328 .type = AK09912,329 .raw_to_gauss = ak09912_raw_to_gauss,330 .range = 32752,331 .ctrl_regs = {332 AK09912_REG_ST1,333 AK09912_REG_ST2,334 AK09912_REG_CNTL2,335 AK09912_REG_ASAX,336 AK09912_MAX_REGS},337 .ctrl_masks = {338 AK09912_REG_ST1_DRDY_MASK,339 AK09912_REG_ST2_HOFL_MASK,340 0,341 AK09912_REG_CNTL2_MODE_MASK},342 .ctrl_modes = {343 AK09912_REG_CNTL_MODE_POWER_DOWN,344 AK09912_REG_CNTL_MODE_ONCE,345 AK09912_REG_CNTL_MODE_SELF_TEST,346 AK09912_REG_CNTL_MODE_FUSE_ROM},347 .data_regs = {348 AK09912_REG_HXL,349 AK09912_REG_HYL,350 AK09912_REG_HZL},351 },352 [AK09916] = {353 .type = AK09916,354 .raw_to_gauss = ak09912_raw_to_gauss,355 .range = 32752,356 .ctrl_regs = {357 AK09912_REG_ST1,358 AK09912_REG_ST2,359 AK09912_REG_CNTL2,360 AK09912_REG_ASAX,361 AK09912_MAX_REGS},362 .ctrl_masks = {363 AK09912_REG_ST1_DRDY_MASK,364 AK09912_REG_ST2_HOFL_MASK,365 0,366 AK09912_REG_CNTL2_MODE_MASK},367 .ctrl_modes = {368 AK09912_REG_CNTL_MODE_POWER_DOWN,369 AK09912_REG_CNTL_MODE_ONCE,370 AK09912_REG_CNTL_MODE_SELF_TEST,371 AK09912_REG_CNTL_MODE_FUSE_ROM},372 .data_regs = {373 AK09912_REG_HXL,374 AK09912_REG_HYL,375 AK09912_REG_HZL},376 },377 [AK09918] = {378 /* ak09918 is register compatible with ak09912 this is for avoid379 * unknown id messages.380 */381 .type = AK09918,382 .raw_to_gauss = ak09912_raw_to_gauss,383 .range = 32752,384 .ctrl_regs = {385 AK09912_REG_ST1,386 AK09912_REG_ST2,387 AK09912_REG_CNTL2,388 AK09912_REG_ASAX,389 AK09912_MAX_REGS},390 .ctrl_masks = {391 AK09912_REG_ST1_DRDY_MASK,392 AK09912_REG_ST2_HOFL_MASK,393 0,394 AK09912_REG_CNTL2_MODE_MASK},395 .ctrl_modes = {396 AK09912_REG_CNTL_MODE_POWER_DOWN,397 AK09912_REG_CNTL_MODE_ONCE,398 AK09912_REG_CNTL_MODE_SELF_TEST,399 AK09912_REG_CNTL_MODE_FUSE_ROM},400 .data_regs = {401 AK09912_REG_HXL,402 AK09912_REG_HYL,403 AK09912_REG_HZL},404 }405};406 407/*408 * Per-instance context data for the device.409 */410struct ak8975_data {411 struct i2c_client *client;412 const struct ak_def *def;413 struct mutex lock;414 u8 asa[3];415 long raw_to_gauss[3];416 struct gpio_desc *eoc_gpiod;417 struct gpio_desc *reset_gpiod;418 int eoc_irq;419 wait_queue_head_t data_ready_queue;420 unsigned long flags;421 u8 cntl_cache;422 struct iio_mount_matrix orientation;423 struct regulator *vdd;424 struct regulator *vid;425 426 /* Ensure natural alignment of timestamp */427 struct {428 s16 channels[3];429 s64 ts __aligned(8);430 } scan;431};432 433/* Enable attached power regulator if any. */434static int ak8975_power_on(const struct ak8975_data *data)435{436 int ret;437 438 ret = regulator_enable(data->vdd);439 if (ret) {440 dev_warn(&data->client->dev,441 "Failed to enable specified Vdd supply\n");442 return ret;443 }444 ret = regulator_enable(data->vid);445 if (ret) {446 dev_warn(&data->client->dev,447 "Failed to enable specified Vid supply\n");448 regulator_disable(data->vdd);449 return ret;450 }451 452 gpiod_set_value_cansleep(data->reset_gpiod, 0);453 454 /*455 * According to the datasheet the power supply rise time is 200us456 * and the minimum wait time before mode setting is 100us, in457 * total 300us. Add some margin and say minimum 500us here.458 */459 usleep_range(500, 1000);460 return 0;461}462 463/* Disable attached power regulator if any. */464static void ak8975_power_off(const struct ak8975_data *data)465{466 gpiod_set_value_cansleep(data->reset_gpiod, 1);467 468 regulator_disable(data->vid);469 regulator_disable(data->vdd);470}471 472/*473 * Return 0 if the i2c device is the one we expect.474 * return a negative error number otherwise475 */476static int ak8975_who_i_am(struct i2c_client *client,477 enum asahi_compass_chipset type)478{479 u8 wia_val[2];480 int ret;481 482 /*483 * Signature for each device:484 * Device | WIA1 | WIA2485 * AK09918 | DEVICE_ID_| AK09918_DEVICE_ID486 * AK09916 | DEVICE_ID_| AK09916_DEVICE_ID487 * AK09912 | DEVICE_ID | AK09912_DEVICE_ID488 * AK09911 | DEVICE_ID | AK09911_DEVICE_ID489 * AK8975 | DEVICE_ID | NA490 * AK8963 | DEVICE_ID | NA491 */492 ret = i2c_smbus_read_i2c_block_data_or_emulated(493 client, AK09912_REG_WIA1, 2, wia_val);494 if (ret < 0) {495 dev_err(&client->dev, "Error reading WIA\n");496 return ret;497 }498 499 if (wia_val[0] != AK8975_DEVICE_ID)500 return -ENODEV;501 502 switch (type) {503 case AK8975:504 case AK8963:505 return 0;506 case AK09911:507 if (wia_val[1] == AK09911_DEVICE_ID)508 return 0;509 break;510 case AK09912:511 if (wia_val[1] == AK09912_DEVICE_ID)512 return 0;513 break;514 case AK09916:515 if (wia_val[1] == AK09916_DEVICE_ID)516 return 0;517 break;518 case AK09918:519 if (wia_val[1] == AK09918_DEVICE_ID)520 return 0;521 break;522 }523 524 dev_info(&client->dev, "Device ID %x is unknown.\n", wia_val[1]);525 /*526 * Let driver to probe on unknown id for support more register527 * compatible variants.528 */529 return 0;530}531 532/*533 * Helper function to write to CNTL register.534 */535static int ak8975_set_mode(struct ak8975_data *data, enum ak_ctrl_mode mode)536{537 u8 regval;538 int ret;539 540 regval = (data->cntl_cache & ~data->def->ctrl_masks[CNTL_MODE]) |541 data->def->ctrl_modes[mode];542 ret = i2c_smbus_write_byte_data(data->client,543 data->def->ctrl_regs[CNTL], regval);544 if (ret < 0) {545 return ret;546 }547 data->cntl_cache = regval;548 /* After mode change wait atleast 100us */549 usleep_range(100, 500);550 551 return 0;552}553 554/*555 * Handle data ready irq556 */557static irqreturn_t ak8975_irq_handler(int irq, void *data)558{559 struct ak8975_data *ak8975 = data;560 561 set_bit(0, &ak8975->flags);562 wake_up(&ak8975->data_ready_queue);563 564 return IRQ_HANDLED;565}566 567/*568 * Install data ready interrupt handler569 */570static int ak8975_setup_irq(struct ak8975_data *data)571{572 struct i2c_client *client = data->client;573 int rc;574 int irq;575 576 init_waitqueue_head(&data->data_ready_queue);577 clear_bit(0, &data->flags);578 if (client->irq)579 irq = client->irq;580 else581 irq = gpiod_to_irq(data->eoc_gpiod);582 583 rc = devm_request_irq(&client->dev, irq, ak8975_irq_handler,584 IRQF_TRIGGER_RISING | IRQF_ONESHOT,585 dev_name(&client->dev), data);586 if (rc < 0) {587 dev_err(&client->dev, "irq %d request failed: %d\n", irq, rc);588 return rc;589 }590 591 data->eoc_irq = irq;592 593 return rc;594}595 596 597/*598 * Perform some start-of-day setup, including reading the asa calibration599 * values and caching them.600 */601static int ak8975_setup(struct i2c_client *client)602{603 struct iio_dev *indio_dev = i2c_get_clientdata(client);604 struct ak8975_data *data = iio_priv(indio_dev);605 int ret;606 607 /* Write the fused rom access mode. */608 ret = ak8975_set_mode(data, FUSE_ROM);609 if (ret < 0) {610 dev_err(&client->dev, "Error in setting fuse access mode\n");611 return ret;612 }613 614 /* Get asa data and store in the device data. */615 ret = i2c_smbus_read_i2c_block_data_or_emulated(616 client, data->def->ctrl_regs[ASA_BASE],617 3, data->asa);618 if (ret < 0) {619 dev_err(&client->dev, "Not able to read asa data\n");620 return ret;621 }622 623 /* After reading fuse ROM data set power-down mode */624 ret = ak8975_set_mode(data, POWER_DOWN);625 if (ret < 0) {626 dev_err(&client->dev, "Error in setting power-down mode\n");627 return ret;628 }629 630 if (data->eoc_gpiod || client->irq > 0) {631 ret = ak8975_setup_irq(data);632 if (ret < 0) {633 dev_err(&client->dev,634 "Error setting data ready interrupt\n");635 return ret;636 }637 }638 639 data->raw_to_gauss[0] = data->def->raw_to_gauss(data->asa[0]);640 data->raw_to_gauss[1] = data->def->raw_to_gauss(data->asa[1]);641 data->raw_to_gauss[2] = data->def->raw_to_gauss(data->asa[2]);642 643 return 0;644}645 646static int wait_conversion_complete_gpio(struct ak8975_data *data)647{648 struct i2c_client *client = data->client;649 u32 timeout_ms = AK8975_MAX_CONVERSION_TIMEOUT;650 int ret;651 652 /* Wait for the conversion to complete. */653 while (timeout_ms) {654 msleep(AK8975_CONVERSION_DONE_POLL_TIME);655 if (gpiod_get_value(data->eoc_gpiod))656 break;657 timeout_ms -= AK8975_CONVERSION_DONE_POLL_TIME;658 }659 if (!timeout_ms) {660 dev_err(&client->dev, "Conversion timeout happened\n");661 return -EINVAL;662 }663 664 ret = i2c_smbus_read_byte_data(client, data->def->ctrl_regs[ST1]);665 if (ret < 0)666 dev_err(&client->dev, "Error in reading ST1\n");667 668 return ret;669}670 671static int wait_conversion_complete_polled(struct ak8975_data *data)672{673 struct i2c_client *client = data->client;674 u8 read_status;675 u32 timeout_ms = AK8975_MAX_CONVERSION_TIMEOUT;676 int ret;677 678 /* Wait for the conversion to complete. */679 while (timeout_ms) {680 msleep(AK8975_CONVERSION_DONE_POLL_TIME);681 ret = i2c_smbus_read_byte_data(client,682 data->def->ctrl_regs[ST1]);683 if (ret < 0) {684 dev_err(&client->dev, "Error in reading ST1\n");685 return ret;686 }687 read_status = ret;688 if (read_status)689 break;690 timeout_ms -= AK8975_CONVERSION_DONE_POLL_TIME;691 }692 if (!timeout_ms) {693 dev_err(&client->dev, "Conversion timeout happened\n");694 return -EINVAL;695 }696 697 return read_status;698}699 700/* Returns 0 if the end of conversion interrupt occured or -ETIME otherwise */701static int wait_conversion_complete_interrupt(struct ak8975_data *data)702{703 int ret;704 705 ret = wait_event_timeout(data->data_ready_queue,706 test_bit(0, &data->flags),707 AK8975_DATA_READY_TIMEOUT);708 clear_bit(0, &data->flags);709 710 return ret > 0 ? 0 : -ETIME;711}712 713static int ak8975_start_read_axis(struct ak8975_data *data,714 const struct i2c_client *client)715{716 /* Set up the device for taking a sample. */717 int ret = ak8975_set_mode(data, MODE_ONCE);718 719 if (ret < 0) {720 dev_err(&client->dev, "Error in setting operating mode\n");721 return ret;722 }723 724 /* Wait for the conversion to complete. */725 if (data->eoc_irq)726 ret = wait_conversion_complete_interrupt(data);727 else if (data->eoc_gpiod)728 ret = wait_conversion_complete_gpio(data);729 else730 ret = wait_conversion_complete_polled(data);731 if (ret < 0)732 return ret;733 734 /* Return with zero if the data is ready. */735 return !data->def->ctrl_regs[ST1_DRDY];736}737 738/* Retrieve raw flux value for one of the x, y, or z axis. */739static int ak8975_read_axis(struct iio_dev *indio_dev, int index, int *val)740{741 struct ak8975_data *data = iio_priv(indio_dev);742 const struct i2c_client *client = data->client;743 const struct ak_def *def = data->def;744 __le16 rval;745 u16 buff;746 int ret;747 748 pm_runtime_get_sync(&data->client->dev);749 750 mutex_lock(&data->lock);751 752 ret = ak8975_start_read_axis(data, client);753 if (ret)754 goto exit;755 756 ret = i2c_smbus_read_i2c_block_data_or_emulated(757 client, def->data_regs[index],758 sizeof(rval), (u8*)&rval);759 if (ret < 0)760 goto exit;761 762 /* Read out ST2 for release lock on measurment data. */763 ret = i2c_smbus_read_byte_data(client, data->def->ctrl_regs[ST2]);764 if (ret < 0) {765 dev_err(&client->dev, "Error in reading ST2\n");766 goto exit;767 }768 769 if (ret & (data->def->ctrl_masks[ST2_DERR] |770 data->def->ctrl_masks[ST2_HOFL])) {771 dev_err(&client->dev, "ST2 status error 0x%x\n", ret);772 ret = -EINVAL;773 goto exit;774 }775 776 mutex_unlock(&data->lock);777 778 pm_runtime_mark_last_busy(&data->client->dev);779 pm_runtime_put_autosuspend(&data->client->dev);780 781 /* Swap bytes and convert to valid range. */782 buff = le16_to_cpu(rval);783 *val = clamp_t(s16, buff, -def->range, def->range);784 return IIO_VAL_INT;785 786exit:787 mutex_unlock(&data->lock);788 dev_err(&client->dev, "Error in reading axis\n");789 return ret;790}791 792static int ak8975_read_raw(struct iio_dev *indio_dev,793 struct iio_chan_spec const *chan,794 int *val, int *val2,795 long mask)796{797 struct ak8975_data *data = iio_priv(indio_dev);798 799 switch (mask) {800 case IIO_CHAN_INFO_RAW:801 return ak8975_read_axis(indio_dev, chan->address, val);802 case IIO_CHAN_INFO_SCALE:803 *val = 0;804 *val2 = data->raw_to_gauss[chan->address];805 return IIO_VAL_INT_PLUS_MICRO;806 }807 return -EINVAL;808}809 810static const struct iio_mount_matrix *811ak8975_get_mount_matrix(const struct iio_dev *indio_dev,812 const struct iio_chan_spec *chan)813{814 struct ak8975_data *data = iio_priv(indio_dev);815 816 return &data->orientation;817}818 819static const struct iio_chan_spec_ext_info ak8975_ext_info[] = {820 IIO_MOUNT_MATRIX(IIO_SHARED_BY_DIR, ak8975_get_mount_matrix),821 { }822};823 824#define AK8975_CHANNEL(axis, index) \825 { \826 .type = IIO_MAGN, \827 .modified = 1, \828 .channel2 = IIO_MOD_##axis, \829 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \830 BIT(IIO_CHAN_INFO_SCALE), \831 .address = index, \832 .scan_index = index, \833 .scan_type = { \834 .sign = 's', \835 .realbits = 16, \836 .storagebits = 16, \837 .endianness = IIO_CPU \838 }, \839 .ext_info = ak8975_ext_info, \840 }841 842static const struct iio_chan_spec ak8975_channels[] = {843 AK8975_CHANNEL(X, 0), AK8975_CHANNEL(Y, 1), AK8975_CHANNEL(Z, 2),844 IIO_CHAN_SOFT_TIMESTAMP(3),845};846 847static const unsigned long ak8975_scan_masks[] = { 0x7, 0 };848 849static const struct iio_info ak8975_info = {850 .read_raw = &ak8975_read_raw,851};852 853static void ak8975_fill_buffer(struct iio_dev *indio_dev)854{855 struct ak8975_data *data = iio_priv(indio_dev);856 const struct i2c_client *client = data->client;857 const struct ak_def *def = data->def;858 int ret;859 __le16 fval[3];860 861 mutex_lock(&data->lock);862 863 ret = ak8975_start_read_axis(data, client);864 if (ret)865 goto unlock;866 867 /*868 * For each axis, read the flux value from the appropriate register869 * (the register is specified in the iio device attributes).870 */871 ret = i2c_smbus_read_i2c_block_data_or_emulated(client,872 def->data_regs[0],873 3 * sizeof(fval[0]),874 (u8 *)fval);875 if (ret < 0)876 goto unlock;877 878 mutex_unlock(&data->lock);879 880 /* Clamp to valid range. */881 data->scan.channels[0] = clamp_t(s16, le16_to_cpu(fval[0]), -def->range, def->range);882 data->scan.channels[1] = clamp_t(s16, le16_to_cpu(fval[1]), -def->range, def->range);883 data->scan.channels[2] = clamp_t(s16, le16_to_cpu(fval[2]), -def->range, def->range);884 885 iio_push_to_buffers_with_timestamp(indio_dev, &data->scan,886 iio_get_time_ns(indio_dev));887 888 return;889 890unlock:891 mutex_unlock(&data->lock);892 dev_err(&client->dev, "Error in reading axes block\n");893}894 895static irqreturn_t ak8975_handle_trigger(int irq, void *p)896{897 const struct iio_poll_func *pf = p;898 struct iio_dev *indio_dev = pf->indio_dev;899 900 ak8975_fill_buffer(indio_dev);901 iio_trigger_notify_done(indio_dev->trig);902 return IRQ_HANDLED;903}904 905static int ak8975_probe(struct i2c_client *client)906{907 const struct i2c_device_id *id = i2c_client_get_device_id(client);908 struct ak8975_data *data;909 struct iio_dev *indio_dev;910 struct gpio_desc *eoc_gpiod;911 struct gpio_desc *reset_gpiod;912 int err;913 const char *name = NULL;914 915 /*916 * Grab and set up the supplied GPIO.917 * We may not have a GPIO based IRQ to scan, that is fine, we will918 * poll if so.919 */920 eoc_gpiod = devm_gpiod_get_optional(&client->dev, NULL, GPIOD_IN);921 if (IS_ERR(eoc_gpiod))922 return PTR_ERR(eoc_gpiod);923 if (eoc_gpiod)924 gpiod_set_consumer_name(eoc_gpiod, "ak_8975");925 926 /*927 * According to AK09911 datasheet, if reset GPIO is provided then928 * deassert reset on ak8975_power_on() and assert reset on929 * ak8975_power_off().930 */931 reset_gpiod = devm_gpiod_get_optional(&client->dev,932 "reset", GPIOD_OUT_HIGH);933 if (IS_ERR(reset_gpiod))934 return PTR_ERR(reset_gpiod);935 936 /* Register with IIO */937 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));938 if (indio_dev == NULL)939 return -ENOMEM;940 941 data = iio_priv(indio_dev);942 i2c_set_clientdata(client, indio_dev);943 944 data->client = client;945 data->eoc_gpiod = eoc_gpiod;946 data->reset_gpiod = reset_gpiod;947 data->eoc_irq = 0;948 949 err = iio_read_mount_matrix(&client->dev, &data->orientation);950 if (err)951 return err;952 953 /* id will be NULL when enumerated via ACPI */954 data->def = i2c_get_match_data(client);955 if (!data->def)956 return -ENODEV;957 958 /* If enumerated via firmware node, fix the ABI */959 if (dev_fwnode(&client->dev))960 name = dev_name(&client->dev);961 else962 name = id->name;963 964 /* Fetch the regulators */965 data->vdd = devm_regulator_get(&client->dev, "vdd");966 if (IS_ERR(data->vdd))967 return PTR_ERR(data->vdd);968 data->vid = devm_regulator_get(&client->dev, "vid");969 if (IS_ERR(data->vid))970 return PTR_ERR(data->vid);971 972 err = ak8975_power_on(data);973 if (err)974 return err;975 976 err = ak8975_who_i_am(client, data->def->type);977 if (err < 0) {978 dev_err(&client->dev, "Unexpected device\n");979 goto power_off;980 }981 dev_dbg(&client->dev, "Asahi compass chip %s\n", name);982 983 /* Perform some basic start-of-day setup of the device. */984 err = ak8975_setup(client);985 if (err < 0) {986 dev_err(&client->dev, "%s initialization fails\n", name);987 goto power_off;988 }989 990 mutex_init(&data->lock);991 indio_dev->channels = ak8975_channels;992 indio_dev->num_channels = ARRAY_SIZE(ak8975_channels);993 indio_dev->info = &ak8975_info;994 indio_dev->available_scan_masks = ak8975_scan_masks;995 indio_dev->modes = INDIO_DIRECT_MODE;996 indio_dev->name = name;997 998 err = iio_triggered_buffer_setup(indio_dev, NULL, ak8975_handle_trigger,999 NULL);1000 if (err) {1001 dev_err(&client->dev, "triggered buffer setup failed\n");1002 goto power_off;1003 }1004 1005 err = iio_device_register(indio_dev);1006 if (err) {1007 dev_err(&client->dev, "device register failed\n");1008 goto cleanup_buffer;1009 }1010 1011 /* Enable runtime PM */1012 pm_runtime_get_noresume(&client->dev);1013 pm_runtime_set_active(&client->dev);1014 pm_runtime_enable(&client->dev);1015 /*1016 * The device comes online in 500us, so add two orders of magnitude1017 * of delay before autosuspending: 50 ms.1018 */1019 pm_runtime_set_autosuspend_delay(&client->dev, 50);1020 pm_runtime_use_autosuspend(&client->dev);1021 pm_runtime_put(&client->dev);1022 1023 return 0;1024 1025cleanup_buffer:1026 iio_triggered_buffer_cleanup(indio_dev);1027power_off:1028 ak8975_power_off(data);1029 return err;1030}1031 1032static void ak8975_remove(struct i2c_client *client)1033{1034 struct iio_dev *indio_dev = i2c_get_clientdata(client);1035 struct ak8975_data *data = iio_priv(indio_dev);1036 1037 pm_runtime_get_sync(&client->dev);1038 pm_runtime_put_noidle(&client->dev);1039 pm_runtime_disable(&client->dev);1040 iio_device_unregister(indio_dev);1041 iio_triggered_buffer_cleanup(indio_dev);1042 ak8975_set_mode(data, POWER_DOWN);1043 ak8975_power_off(data);1044}1045 1046static int ak8975_runtime_suspend(struct device *dev)1047{1048 struct i2c_client *client = to_i2c_client(dev);1049 struct iio_dev *indio_dev = i2c_get_clientdata(client);1050 struct ak8975_data *data = iio_priv(indio_dev);1051 int ret;1052 1053 /* Set the device in power down if it wasn't already */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 /* Next cut the regulators */1060 ak8975_power_off(data);1061 1062 return 0;1063}1064 1065static int ak8975_runtime_resume(struct device *dev)1066{1067 struct i2c_client *client = to_i2c_client(dev);1068 struct iio_dev *indio_dev = i2c_get_clientdata(client);1069 struct ak8975_data *data = iio_priv(indio_dev);1070 int ret;1071 1072 /* Take up the regulators */1073 ak8975_power_on(data);1074 /*1075 * We come up in powered down mode, the reading routines will1076 * put us in the mode to read values later.1077 */1078 ret = ak8975_set_mode(data, POWER_DOWN);1079 if (ret < 0) {1080 dev_err(&client->dev, "Error in setting power-down mode\n");1081 return ret;1082 }1083 1084 return 0;1085}1086 1087static DEFINE_RUNTIME_DEV_PM_OPS(ak8975_dev_pm_ops, ak8975_runtime_suspend,1088 ak8975_runtime_resume, NULL);1089 1090static const struct acpi_device_id ak_acpi_match[] = {1091 {"AK8963", (kernel_ulong_t)&ak_def_array[AK8963] },1092 {"AK8975", (kernel_ulong_t)&ak_def_array[AK8975] },1093 {"AK009911", (kernel_ulong_t)&ak_def_array[AK09911] },1094 {"AK09911", (kernel_ulong_t)&ak_def_array[AK09911] },1095 {"AK09912", (kernel_ulong_t)&ak_def_array[AK09912] },1096 {"AKM9911", (kernel_ulong_t)&ak_def_array[AK09911] },1097 {"INVN6500", (kernel_ulong_t)&ak_def_array[AK8963] },1098 { }1099};1100MODULE_DEVICE_TABLE(acpi, ak_acpi_match);1101 1102static const struct i2c_device_id ak8975_id[] = {1103 {"AK8963", (kernel_ulong_t)&ak_def_array[AK8963] },1104 {"ak8963", (kernel_ulong_t)&ak_def_array[AK8963] },1105 {"ak8975", (kernel_ulong_t)&ak_def_array[AK8975] },1106 {"ak09911", (kernel_ulong_t)&ak_def_array[AK09911] },1107 {"ak09912", (kernel_ulong_t)&ak_def_array[AK09912] },1108 {"ak09916", (kernel_ulong_t)&ak_def_array[AK09916] },1109 {"ak09918", (kernel_ulong_t)&ak_def_array[AK09918] },1110 {}1111};1112MODULE_DEVICE_TABLE(i2c, ak8975_id);1113 1114static const struct of_device_id ak8975_of_match[] = {1115 { .compatible = "asahi-kasei,ak8975", .data = &ak_def_array[AK8975] },1116 { .compatible = "ak8975", .data = &ak_def_array[AK8975] },1117 { .compatible = "asahi-kasei,ak8963", .data = &ak_def_array[AK8963] },1118 { .compatible = "ak8963", .data = &ak_def_array[AK8963] },1119 { .compatible = "asahi-kasei,ak09911", .data = &ak_def_array[AK09911] },1120 { .compatible = "ak09911", .data = &ak_def_array[AK09911] },1121 { .compatible = "asahi-kasei,ak09912", .data = &ak_def_array[AK09912] },1122 { .compatible = "ak09912", .data = &ak_def_array[AK09912] },1123 { .compatible = "asahi-kasei,ak09916", .data = &ak_def_array[AK09916] },1124 { .compatible = "asahi-kasei,ak09918", .data = &ak_def_array[AK09918] },1125 {}1126};1127MODULE_DEVICE_TABLE(of, ak8975_of_match);1128 1129static struct i2c_driver ak8975_driver = {1130 .driver = {1131 .name = "ak8975",1132 .pm = pm_ptr(&ak8975_dev_pm_ops),1133 .of_match_table = ak8975_of_match,1134 .acpi_match_table = ak_acpi_match,1135 },1136 .probe = ak8975_probe,1137 .remove = ak8975_remove,1138 .id_table = ak8975_id,1139};1140module_i2c_driver(ak8975_driver);1141 1142MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");1143MODULE_DESCRIPTION("AK8975 magnetometer driver");1144MODULE_LICENSE("GPL");1145