653 lines · c
1// SPDX-License-Identifier: GPL-2.0-only2/*3 * mag3110.c - Support for Freescale MAG3110 magnetometer sensor4 *5 * Copyright (c) 2013 Peter Meerwald <pmeerw@pmeerw.net>6 *7 * (7-bit I2C slave address 0x0e)8 *9 * TODO: irq, user offset, oversampling, continuous mode10 */11 12#include <linux/module.h>13#include <linux/i2c.h>14#include <linux/iio/iio.h>15#include <linux/iio/sysfs.h>16#include <linux/iio/trigger_consumer.h>17#include <linux/iio/buffer.h>18#include <linux/iio/triggered_buffer.h>19#include <linux/delay.h>20#include <linux/regulator/consumer.h>21 22#define MAG3110_STATUS 0x0023#define MAG3110_OUT_X 0x01 /* MSB first */24#define MAG3110_OUT_Y 0x0325#define MAG3110_OUT_Z 0x0526#define MAG3110_WHO_AM_I 0x0727#define MAG3110_SYSMOD 0x0828#define MAG3110_OFF_X 0x09 /* MSB first */29#define MAG3110_OFF_Y 0x0b30#define MAG3110_OFF_Z 0x0d31#define MAG3110_DIE_TEMP 0x0f32#define MAG3110_CTRL_REG1 0x1033#define MAG3110_CTRL_REG2 0x1134 35#define MAG3110_STATUS_DRDY (BIT(2) | BIT(1) | BIT(0))36 37#define MAG3110_CTRL_DR_MASK (BIT(7) | BIT(6) | BIT(5))38#define MAG3110_CTRL_DR_SHIFT 539#define MAG3110_CTRL_DR_DEFAULT 040 41#define MAG3110_SYSMOD_MODE_MASK GENMASK(1, 0)42 43#define MAG3110_CTRL_TM BIT(1) /* trigger single measurement */44#define MAG3110_CTRL_AC BIT(0) /* continuous measurements */45 46#define MAG3110_CTRL_AUTO_MRST_EN BIT(7) /* magnetic auto-reset */47#define MAG3110_CTRL_RAW BIT(5) /* measurements not user-offset corrected */48 49#define MAG3110_DEVICE_ID 0xc450 51/* Each client has this additional data */52struct mag3110_data {53 struct i2c_client *client;54 struct mutex lock;55 u8 ctrl_reg1;56 int sleep_val;57 struct regulator *vdd_reg;58 struct regulator *vddio_reg;59 /* Ensure natural alignment of timestamp */60 struct {61 __be16 channels[3];62 u8 temperature;63 s64 ts __aligned(8);64 } scan;65};66 67static int mag3110_request(struct mag3110_data *data)68{69 int ret, tries = 150;70 71 if ((data->ctrl_reg1 & MAG3110_CTRL_AC) == 0) {72 /* trigger measurement */73 ret = i2c_smbus_write_byte_data(data->client, MAG3110_CTRL_REG1,74 data->ctrl_reg1 | MAG3110_CTRL_TM);75 if (ret < 0)76 return ret;77 }78 79 while (tries-- > 0) {80 ret = i2c_smbus_read_byte_data(data->client, MAG3110_STATUS);81 if (ret < 0)82 return ret;83 /* wait for data ready */84 if ((ret & MAG3110_STATUS_DRDY) == MAG3110_STATUS_DRDY)85 break;86 87 if (data->sleep_val <= 20)88 usleep_range(data->sleep_val * 250, data->sleep_val * 500);89 else90 msleep(20);91 }92 93 if (tries < 0) {94 dev_err(&data->client->dev, "data not ready\n");95 return -EIO;96 }97 98 return 0;99}100 101static int mag3110_read(struct mag3110_data *data, __be16 buf[3])102{103 int ret;104 105 mutex_lock(&data->lock);106 ret = mag3110_request(data);107 if (ret < 0) {108 mutex_unlock(&data->lock);109 return ret;110 }111 ret = i2c_smbus_read_i2c_block_data(data->client,112 MAG3110_OUT_X, 3 * sizeof(__be16), (u8 *) buf);113 mutex_unlock(&data->lock);114 115 return ret;116}117 118static ssize_t mag3110_show_int_plus_micros(char *buf,119 const int (*vals)[2], int n)120{121 size_t len = 0;122 123 while (n-- > 0)124 len += scnprintf(buf + len, PAGE_SIZE - len,125 "%d.%06d ", vals[n][0], vals[n][1]);126 127 /* replace trailing space by newline */128 buf[len - 1] = '\n';129 130 return len;131}132 133static int mag3110_get_int_plus_micros_index(const int (*vals)[2], int n,134 int val, int val2)135{136 while (n-- > 0)137 if (val == vals[n][0] && val2 == vals[n][1])138 return n;139 140 return -EINVAL;141}142 143static const int mag3110_samp_freq[8][2] = {144 {80, 0}, {40, 0}, {20, 0}, {10, 0}, {5, 0}, {2, 500000},145 {1, 250000}, {0, 625000}146};147 148static ssize_t mag3110_show_samp_freq_avail(struct device *dev,149 struct device_attribute *attr, char *buf)150{151 return mag3110_show_int_plus_micros(buf, mag3110_samp_freq, 8);152}153 154static IIO_DEV_ATTR_SAMP_FREQ_AVAIL(mag3110_show_samp_freq_avail);155 156static int mag3110_get_samp_freq_index(struct mag3110_data *data,157 int val, int val2)158{159 return mag3110_get_int_plus_micros_index(mag3110_samp_freq, 8, val,160 val2);161}162 163static int mag3110_calculate_sleep(struct mag3110_data *data)164{165 int ret, i = data->ctrl_reg1 >> MAG3110_CTRL_DR_SHIFT;166 167 if (mag3110_samp_freq[i][0] > 0)168 ret = 1000 / mag3110_samp_freq[i][0];169 else170 ret = 1000;171 172 return ret == 0 ? 1 : ret;173}174 175static int mag3110_standby(struct mag3110_data *data)176{177 return i2c_smbus_write_byte_data(data->client, MAG3110_CTRL_REG1,178 data->ctrl_reg1 & ~MAG3110_CTRL_AC);179}180 181static int mag3110_wait_standby(struct mag3110_data *data)182{183 int ret, tries = 30;184 185 /*186 * Takes up to 1/ODR to come out of active mode into stby187 * Longest expected period is 12.5seconds.188 * We'll sleep for 500ms between checks189 */190 while (tries-- > 0) {191 ret = i2c_smbus_read_byte_data(data->client, MAG3110_SYSMOD);192 if (ret < 0) {193 dev_err(&data->client->dev, "i2c error\n");194 return ret;195 }196 /* wait for standby */197 if ((ret & MAG3110_SYSMOD_MODE_MASK) == 0)198 break;199 200 msleep_interruptible(500);201 }202 203 if (tries < 0) {204 dev_err(&data->client->dev, "device not entering standby mode\n");205 return -EIO;206 }207 208 return 0;209}210 211static int mag3110_active(struct mag3110_data *data)212{213 return i2c_smbus_write_byte_data(data->client, MAG3110_CTRL_REG1,214 data->ctrl_reg1);215}216 217/* returns >0 if active, 0 if in standby and <0 on error */218static int mag3110_is_active(struct mag3110_data *data)219{220 int reg;221 222 reg = i2c_smbus_read_byte_data(data->client, MAG3110_CTRL_REG1);223 if (reg < 0)224 return reg;225 226 return reg & MAG3110_CTRL_AC;227}228 229static int mag3110_change_config(struct mag3110_data *data, u8 reg, u8 val)230{231 int ret;232 int is_active;233 234 mutex_lock(&data->lock);235 236 is_active = mag3110_is_active(data);237 if (is_active < 0) {238 ret = is_active;239 goto fail;240 }241 242 /* config can only be changed when in standby */243 if (is_active > 0) {244 ret = mag3110_standby(data);245 if (ret < 0)246 goto fail;247 }248 249 /*250 * After coming out of active we must wait for the part251 * to transition to STBY. This can take up to 1 /ODR to occur252 */253 ret = mag3110_wait_standby(data);254 if (ret < 0)255 goto fail;256 257 ret = i2c_smbus_write_byte_data(data->client, reg, val);258 if (ret < 0)259 goto fail;260 261 if (is_active > 0) {262 ret = mag3110_active(data);263 if (ret < 0)264 goto fail;265 }266 267 ret = 0;268fail:269 mutex_unlock(&data->lock);270 271 return ret;272}273 274static int mag3110_read_raw(struct iio_dev *indio_dev,275 struct iio_chan_spec const *chan,276 int *val, int *val2, long mask)277{278 struct mag3110_data *data = iio_priv(indio_dev);279 __be16 buffer[3];280 int i, ret;281 282 switch (mask) {283 case IIO_CHAN_INFO_RAW:284 ret = iio_device_claim_direct_mode(indio_dev);285 if (ret)286 return ret;287 288 switch (chan->type) {289 case IIO_MAGN: /* in 0.1 uT / LSB */290 ret = mag3110_read(data, buffer);291 if (ret < 0)292 goto release;293 *val = sign_extend32(294 be16_to_cpu(buffer[chan->scan_index]),295 chan->scan_type.realbits - 1);296 ret = IIO_VAL_INT;297 break;298 case IIO_TEMP: /* in 1 C / LSB */299 mutex_lock(&data->lock);300 ret = mag3110_request(data);301 if (ret < 0) {302 mutex_unlock(&data->lock);303 goto release;304 }305 ret = i2c_smbus_read_byte_data(data->client,306 MAG3110_DIE_TEMP);307 mutex_unlock(&data->lock);308 if (ret < 0)309 goto release;310 *val = sign_extend32(ret,311 chan->scan_type.realbits - 1);312 ret = IIO_VAL_INT;313 break;314 default:315 ret = -EINVAL;316 }317release:318 iio_device_release_direct_mode(indio_dev);319 return ret;320 321 case IIO_CHAN_INFO_SCALE:322 switch (chan->type) {323 case IIO_MAGN:324 *val = 0;325 *val2 = 1000;326 return IIO_VAL_INT_PLUS_MICRO;327 case IIO_TEMP:328 *val = 1000;329 return IIO_VAL_INT;330 default:331 return -EINVAL;332 }333 case IIO_CHAN_INFO_SAMP_FREQ:334 i = data->ctrl_reg1 >> MAG3110_CTRL_DR_SHIFT;335 *val = mag3110_samp_freq[i][0];336 *val2 = mag3110_samp_freq[i][1];337 return IIO_VAL_INT_PLUS_MICRO;338 case IIO_CHAN_INFO_CALIBBIAS:339 ret = i2c_smbus_read_word_swapped(data->client,340 MAG3110_OFF_X + 2 * chan->scan_index);341 if (ret < 0)342 return ret;343 *val = sign_extend32(ret >> 1, 14);344 return IIO_VAL_INT;345 }346 return -EINVAL;347}348 349static int mag3110_write_raw(struct iio_dev *indio_dev,350 struct iio_chan_spec const *chan,351 int val, int val2, long mask)352{353 struct mag3110_data *data = iio_priv(indio_dev);354 int rate, ret;355 356 ret = iio_device_claim_direct_mode(indio_dev);357 if (ret)358 return ret;359 360 switch (mask) {361 case IIO_CHAN_INFO_SAMP_FREQ:362 rate = mag3110_get_samp_freq_index(data, val, val2);363 if (rate < 0) {364 ret = -EINVAL;365 break;366 }367 data->ctrl_reg1 &= 0xff & ~MAG3110_CTRL_DR_MASK368 & ~MAG3110_CTRL_AC;369 data->ctrl_reg1 |= rate << MAG3110_CTRL_DR_SHIFT;370 data->sleep_val = mag3110_calculate_sleep(data);371 if (data->sleep_val < 40)372 data->ctrl_reg1 |= MAG3110_CTRL_AC;373 374 ret = mag3110_change_config(data, MAG3110_CTRL_REG1,375 data->ctrl_reg1);376 break;377 case IIO_CHAN_INFO_CALIBBIAS:378 if (val < -10000 || val > 10000) {379 ret = -EINVAL;380 break;381 }382 ret = i2c_smbus_write_word_swapped(data->client,383 MAG3110_OFF_X + 2 * chan->scan_index, val << 1);384 break;385 default:386 ret = -EINVAL;387 break;388 }389 iio_device_release_direct_mode(indio_dev);390 return ret;391}392 393static irqreturn_t mag3110_trigger_handler(int irq, void *p)394{395 struct iio_poll_func *pf = p;396 struct iio_dev *indio_dev = pf->indio_dev;397 struct mag3110_data *data = iio_priv(indio_dev);398 int ret;399 400 ret = mag3110_read(data, data->scan.channels);401 if (ret < 0)402 goto done;403 404 if (test_bit(3, indio_dev->active_scan_mask)) {405 ret = i2c_smbus_read_byte_data(data->client,406 MAG3110_DIE_TEMP);407 if (ret < 0)408 goto done;409 data->scan.temperature = ret;410 }411 412 iio_push_to_buffers_with_timestamp(indio_dev, &data->scan,413 iio_get_time_ns(indio_dev));414 415done:416 iio_trigger_notify_done(indio_dev->trig);417 return IRQ_HANDLED;418}419 420#define MAG3110_CHANNEL(axis, idx) { \421 .type = IIO_MAGN, \422 .modified = 1, \423 .channel2 = IIO_MOD_##axis, \424 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \425 BIT(IIO_CHAN_INFO_CALIBBIAS), \426 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SAMP_FREQ) | \427 BIT(IIO_CHAN_INFO_SCALE), \428 .scan_index = idx, \429 .scan_type = { \430 .sign = 's', \431 .realbits = 16, \432 .storagebits = 16, \433 .endianness = IIO_BE, \434 }, \435}436 437static const struct iio_chan_spec mag3110_channels[] = {438 MAG3110_CHANNEL(X, 0),439 MAG3110_CHANNEL(Y, 1),440 MAG3110_CHANNEL(Z, 2),441 {442 .type = IIO_TEMP,443 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |444 BIT(IIO_CHAN_INFO_SCALE),445 .scan_index = 3,446 .scan_type = {447 .sign = 's',448 .realbits = 8,449 .storagebits = 8,450 },451 },452 IIO_CHAN_SOFT_TIMESTAMP(4),453};454 455static struct attribute *mag3110_attributes[] = {456 &iio_dev_attr_sampling_frequency_available.dev_attr.attr,457 NULL458};459 460static const struct attribute_group mag3110_group = {461 .attrs = mag3110_attributes,462};463 464static const struct iio_info mag3110_info = {465 .attrs = &mag3110_group,466 .read_raw = &mag3110_read_raw,467 .write_raw = &mag3110_write_raw,468};469 470static const unsigned long mag3110_scan_masks[] = {0x7, 0xf, 0};471 472static int mag3110_probe(struct i2c_client *client)473{474 const struct i2c_device_id *id = i2c_client_get_device_id(client);475 struct mag3110_data *data;476 struct iio_dev *indio_dev;477 int ret;478 479 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));480 if (!indio_dev)481 return -ENOMEM;482 483 data = iio_priv(indio_dev);484 485 data->vdd_reg = devm_regulator_get(&client->dev, "vdd");486 if (IS_ERR(data->vdd_reg))487 return dev_err_probe(&client->dev, PTR_ERR(data->vdd_reg),488 "failed to get VDD regulator!\n");489 490 data->vddio_reg = devm_regulator_get(&client->dev, "vddio");491 if (IS_ERR(data->vddio_reg))492 return dev_err_probe(&client->dev, PTR_ERR(data->vddio_reg),493 "failed to get VDDIO regulator!\n");494 495 ret = regulator_enable(data->vdd_reg);496 if (ret) {497 dev_err(&client->dev, "failed to enable VDD regulator!\n");498 return ret;499 }500 501 ret = regulator_enable(data->vddio_reg);502 if (ret) {503 dev_err(&client->dev, "failed to enable VDDIO regulator!\n");504 goto disable_regulator_vdd;505 }506 507 ret = i2c_smbus_read_byte_data(client, MAG3110_WHO_AM_I);508 if (ret < 0)509 goto disable_regulators;510 if (ret != MAG3110_DEVICE_ID) {511 ret = -ENODEV;512 goto disable_regulators;513 }514 515 data->client = client;516 mutex_init(&data->lock);517 518 i2c_set_clientdata(client, indio_dev);519 indio_dev->info = &mag3110_info;520 indio_dev->name = id->name;521 indio_dev->modes = INDIO_DIRECT_MODE;522 indio_dev->channels = mag3110_channels;523 indio_dev->num_channels = ARRAY_SIZE(mag3110_channels);524 indio_dev->available_scan_masks = mag3110_scan_masks;525 526 data->ctrl_reg1 = MAG3110_CTRL_DR_DEFAULT << MAG3110_CTRL_DR_SHIFT;527 data->sleep_val = mag3110_calculate_sleep(data);528 if (data->sleep_val < 40)529 data->ctrl_reg1 |= MAG3110_CTRL_AC;530 531 ret = mag3110_change_config(data, MAG3110_CTRL_REG1, data->ctrl_reg1);532 if (ret < 0)533 goto disable_regulators;534 535 ret = i2c_smbus_write_byte_data(client, MAG3110_CTRL_REG2,536 MAG3110_CTRL_AUTO_MRST_EN);537 if (ret < 0)538 goto standby_on_error;539 540 ret = iio_triggered_buffer_setup(indio_dev, NULL,541 mag3110_trigger_handler, NULL);542 if (ret < 0)543 goto standby_on_error;544 545 ret = iio_device_register(indio_dev);546 if (ret < 0)547 goto buffer_cleanup;548 return 0;549 550buffer_cleanup:551 iio_triggered_buffer_cleanup(indio_dev);552standby_on_error:553 mag3110_standby(iio_priv(indio_dev));554disable_regulators:555 regulator_disable(data->vddio_reg);556disable_regulator_vdd:557 regulator_disable(data->vdd_reg);558 559 return ret;560}561 562static void mag3110_remove(struct i2c_client *client)563{564 struct iio_dev *indio_dev = i2c_get_clientdata(client);565 struct mag3110_data *data = iio_priv(indio_dev);566 567 iio_device_unregister(indio_dev);568 iio_triggered_buffer_cleanup(indio_dev);569 mag3110_standby(iio_priv(indio_dev));570 regulator_disable(data->vddio_reg);571 regulator_disable(data->vdd_reg);572}573 574static int mag3110_suspend(struct device *dev)575{576 struct mag3110_data *data = iio_priv(i2c_get_clientdata(577 to_i2c_client(dev)));578 int ret;579 580 ret = mag3110_standby(iio_priv(i2c_get_clientdata(581 to_i2c_client(dev))));582 if (ret)583 return ret;584 585 ret = regulator_disable(data->vddio_reg);586 if (ret) {587 dev_err(dev, "failed to disable VDDIO regulator\n");588 return ret;589 }590 591 ret = regulator_disable(data->vdd_reg);592 if (ret) {593 dev_err(dev, "failed to disable VDD regulator\n");594 return ret;595 }596 597 return 0;598}599 600static int mag3110_resume(struct device *dev)601{602 struct mag3110_data *data = iio_priv(i2c_get_clientdata(603 to_i2c_client(dev)));604 int ret;605 606 ret = regulator_enable(data->vdd_reg);607 if (ret) {608 dev_err(dev, "failed to enable VDD regulator\n");609 return ret;610 }611 612 ret = regulator_enable(data->vddio_reg);613 if (ret) {614 dev_err(dev, "failed to enable VDDIO regulator\n");615 regulator_disable(data->vdd_reg);616 return ret;617 }618 619 return i2c_smbus_write_byte_data(data->client, MAG3110_CTRL_REG1,620 data->ctrl_reg1);621}622 623static DEFINE_SIMPLE_DEV_PM_OPS(mag3110_pm_ops, mag3110_suspend,624 mag3110_resume);625 626static const struct i2c_device_id mag3110_id[] = {627 { "mag3110" },628 { }629};630MODULE_DEVICE_TABLE(i2c, mag3110_id);631 632static const struct of_device_id mag3110_of_match[] = {633 { .compatible = "fsl,mag3110" },634 { }635};636MODULE_DEVICE_TABLE(of, mag3110_of_match);637 638static struct i2c_driver mag3110_driver = {639 .driver = {640 .name = "mag3110",641 .of_match_table = mag3110_of_match,642 .pm = pm_sleep_ptr(&mag3110_pm_ops),643 },644 .probe = mag3110_probe,645 .remove = mag3110_remove,646 .id_table = mag3110_id,647};648module_i2c_driver(mag3110_driver);649 650MODULE_AUTHOR("Peter Meerwald <pmeerw@pmeerw.net>");651MODULE_DESCRIPTION("Freescale MAG3110 magnetometer driver");652MODULE_LICENSE("GPL");653