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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * Sensortek STK8312 3-Axis Accelerometer4 *5 * Copyright (c) 2015, Intel Corporation.6 *7 * IIO driver for STK8312; 7-bit I2C address: 0x3D.8 */9 10#include <linux/i2c.h>11#include <linux/interrupt.h>12#include <linux/kernel.h>13#include <linux/module.h>14#include <linux/delay.h>15#include <linux/iio/buffer.h>16#include <linux/iio/iio.h>17#include <linux/iio/sysfs.h>18#include <linux/iio/trigger.h>19#include <linux/iio/triggered_buffer.h>20#include <linux/iio/trigger_consumer.h>21 22#define STK8312_REG_XOUT 0x0023#define STK8312_REG_YOUT 0x0124#define STK8312_REG_ZOUT 0x0225#define STK8312_REG_INTSU 0x0626#define STK8312_REG_MODE 0x0727#define STK8312_REG_SR 0x0828#define STK8312_REG_STH 0x1329#define STK8312_REG_RESET 0x2030#define STK8312_REG_AFECTRL 0x2431#define STK8312_REG_OTPADDR 0x3D32#define STK8312_REG_OTPDATA 0x3E33#define STK8312_REG_OTPCTRL 0x3F34 35#define STK8312_MODE_ACTIVE BIT(0)36#define STK8312_MODE_STANDBY 0x0037#define STK8312_MODE_INT_AH_PP 0xC0 /* active-high, push-pull */38#define STK8312_DREADY_BIT BIT(4)39#define STK8312_RNG_6G 140#define STK8312_RNG_SHIFT 641#define STK8312_RNG_MASK GENMASK(7, 6)42#define STK8312_SR_MASK GENMASK(2, 0)43#define STK8312_SR_400HZ_IDX 044#define STK8312_ALL_CHANNEL_MASK GENMASK(2, 0)45#define STK8312_ALL_CHANNEL_SIZE 346 47#define STK8312_DRIVER_NAME "stk8312"48#define STK8312_IRQ_NAME "stk8312_event"49 50/*51 * The accelerometer has two measurement ranges:52 *53 * -6g - +6g (8-bit, signed)54 * -16g - +16g (8-bit, signed)55 *56 * scale1 = (6 + 6) * 9.81 / (2^8 - 1) = 0.461657 * scale2 = (16 + 16) * 9.81 / (2^8 - 1) = 1.231158 */59#define STK8312_SCALE_AVAIL "0.4616 1.2311"60 61static const int stk8312_scale_table[][2] = {62 {0, 461600}, {1, 231100}63};64 65static const struct {66 int val;67 int val2;68} stk8312_samp_freq_table[] = {69 {400, 0}, {200, 0}, {100, 0}, {50, 0}, {25, 0},70 {12, 500000}, {6, 250000}, {3, 125000}71};72 73#define STK8312_ACCEL_CHANNEL(index, reg, axis) { \74 .type = IIO_ACCEL, \75 .address = reg, \76 .modified = 1, \77 .channel2 = IIO_MOD_##axis, \78 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \79 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) | \80 BIT(IIO_CHAN_INFO_SAMP_FREQ), \81 .scan_index = index, \82 .scan_type = { \83 .sign = 's', \84 .realbits = 8, \85 .storagebits = 8, \86 .endianness = IIO_CPU, \87 }, \88}89 90static const struct iio_chan_spec stk8312_channels[] = {91 STK8312_ACCEL_CHANNEL(0, STK8312_REG_XOUT, X),92 STK8312_ACCEL_CHANNEL(1, STK8312_REG_YOUT, Y),93 STK8312_ACCEL_CHANNEL(2, STK8312_REG_ZOUT, Z),94 IIO_CHAN_SOFT_TIMESTAMP(3),95};96 97struct stk8312_data {98 struct i2c_client *client;99 struct mutex lock;100 u8 range;101 u8 sample_rate_idx;102 u8 mode;103 struct iio_trigger *dready_trig;104 bool dready_trigger_on;105 /* Ensure timestamp is naturally aligned */106 struct {107 s8 chans[3];108 s64 timestamp __aligned(8);109 } scan;110};111 112static IIO_CONST_ATTR(in_accel_scale_available, STK8312_SCALE_AVAIL);113 114static IIO_CONST_ATTR_SAMP_FREQ_AVAIL("3.125 6.25 12.5 25 50 100 200 400");115 116static struct attribute *stk8312_attributes[] = {117 &iio_const_attr_in_accel_scale_available.dev_attr.attr,118 &iio_const_attr_sampling_frequency_available.dev_attr.attr,119 NULL,120};121 122static const struct attribute_group stk8312_attribute_group = {123 .attrs = stk8312_attributes124};125 126static int stk8312_otp_init(struct stk8312_data *data)127{128 int ret;129 int count = 10;130 struct i2c_client *client = data->client;131 132 ret = i2c_smbus_write_byte_data(client, STK8312_REG_OTPADDR, 0x70);133 if (ret < 0)134 goto exit_err;135 ret = i2c_smbus_write_byte_data(client, STK8312_REG_OTPCTRL, 0x02);136 if (ret < 0)137 goto exit_err;138 139 do {140 usleep_range(1000, 5000);141 ret = i2c_smbus_read_byte_data(client, STK8312_REG_OTPCTRL);142 if (ret < 0)143 goto exit_err;144 count--;145 } while (!(ret & BIT(7)) && count > 0);146 147 if (count == 0) {148 ret = -ETIMEDOUT;149 goto exit_err;150 }151 152 ret = i2c_smbus_read_byte_data(client, STK8312_REG_OTPDATA);153 if (ret == 0)154 ret = -EINVAL;155 if (ret < 0)156 goto exit_err;157 158 ret = i2c_smbus_write_byte_data(data->client, STK8312_REG_AFECTRL, ret);159 if (ret < 0)160 goto exit_err;161 msleep(150);162 163 return 0;164 165exit_err:166 dev_err(&client->dev, "failed to initialize sensor\n");167 return ret;168}169 170static int stk8312_set_mode(struct stk8312_data *data, u8 mode)171{172 int ret;173 struct i2c_client *client = data->client;174 175 if (mode == data->mode)176 return 0;177 178 ret = i2c_smbus_write_byte_data(client, STK8312_REG_MODE, mode);179 if (ret < 0) {180 dev_err(&client->dev, "failed to change sensor mode\n");181 return ret;182 }183 184 data->mode = mode;185 if (mode & STK8312_MODE_ACTIVE) {186 /* Need to run OTP sequence before entering active mode */187 usleep_range(1000, 5000);188 ret = stk8312_otp_init(data);189 }190 191 return ret;192}193 194static int stk8312_set_interrupts(struct stk8312_data *data, u8 int_mask)195{196 int ret;197 u8 mode;198 struct i2c_client *client = data->client;199 200 mode = data->mode;201 /* We need to go in standby mode to modify registers */202 ret = stk8312_set_mode(data, STK8312_MODE_STANDBY);203 if (ret < 0)204 return ret;205 206 ret = i2c_smbus_write_byte_data(client, STK8312_REG_INTSU, int_mask);207 if (ret < 0) {208 dev_err(&client->dev, "failed to set interrupts\n");209 stk8312_set_mode(data, mode);210 return ret;211 }212 213 return stk8312_set_mode(data, mode);214}215 216static int stk8312_data_rdy_trigger_set_state(struct iio_trigger *trig,217 bool state)218{219 struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);220 struct stk8312_data *data = iio_priv(indio_dev);221 int ret;222 223 if (state)224 ret = stk8312_set_interrupts(data, STK8312_DREADY_BIT);225 else226 ret = stk8312_set_interrupts(data, 0x00);227 228 if (ret < 0) {229 dev_err(&data->client->dev, "failed to set trigger state\n");230 return ret;231 }232 233 data->dready_trigger_on = state;234 235 return 0;236}237 238static const struct iio_trigger_ops stk8312_trigger_ops = {239 .set_trigger_state = stk8312_data_rdy_trigger_set_state,240};241 242static int stk8312_set_sample_rate(struct stk8312_data *data, u8 rate)243{244 int ret;245 u8 masked_reg;246 u8 mode;247 struct i2c_client *client = data->client;248 249 if (rate == data->sample_rate_idx)250 return 0;251 252 mode = data->mode;253 /* We need to go in standby mode to modify registers */254 ret = stk8312_set_mode(data, STK8312_MODE_STANDBY);255 if (ret < 0)256 return ret;257 258 ret = i2c_smbus_read_byte_data(client, STK8312_REG_SR);259 if (ret < 0)260 goto err_activate;261 262 masked_reg = (ret & (~STK8312_SR_MASK)) | rate;263 264 ret = i2c_smbus_write_byte_data(client, STK8312_REG_SR, masked_reg);265 if (ret < 0)266 goto err_activate;267 268 data->sample_rate_idx = rate;269 270 return stk8312_set_mode(data, mode);271 272err_activate:273 dev_err(&client->dev, "failed to set sampling rate\n");274 stk8312_set_mode(data, mode);275 276 return ret;277}278 279static int stk8312_set_range(struct stk8312_data *data, u8 range)280{281 int ret;282 u8 masked_reg;283 u8 mode;284 struct i2c_client *client = data->client;285 286 if (range != 1 && range != 2)287 return -EINVAL;288 else if (range == data->range)289 return 0;290 291 mode = data->mode;292 /* We need to go in standby mode to modify registers */293 ret = stk8312_set_mode(data, STK8312_MODE_STANDBY);294 if (ret < 0)295 return ret;296 297 ret = i2c_smbus_read_byte_data(client, STK8312_REG_STH);298 if (ret < 0)299 goto err_activate;300 301 masked_reg = ret & (~STK8312_RNG_MASK);302 masked_reg |= range << STK8312_RNG_SHIFT;303 304 ret = i2c_smbus_write_byte_data(client, STK8312_REG_STH, masked_reg);305 if (ret < 0)306 goto err_activate;307 308 data->range = range;309 310 return stk8312_set_mode(data, mode);311 312err_activate:313 dev_err(&client->dev, "failed to change sensor range\n");314 stk8312_set_mode(data, mode);315 316 return ret;317}318 319static int stk8312_read_accel(struct stk8312_data *data, u8 address)320{321 int ret;322 struct i2c_client *client = data->client;323 324 if (address > 2)325 return -EINVAL;326 327 ret = i2c_smbus_read_byte_data(client, address);328 if (ret < 0)329 dev_err(&client->dev, "register read failed\n");330 331 return ret;332}333 334static int stk8312_read_raw(struct iio_dev *indio_dev,335 struct iio_chan_spec const *chan,336 int *val, int *val2, long mask)337{338 struct stk8312_data *data = iio_priv(indio_dev);339 int ret;340 341 switch (mask) {342 case IIO_CHAN_INFO_RAW:343 if (iio_buffer_enabled(indio_dev))344 return -EBUSY;345 mutex_lock(&data->lock);346 ret = stk8312_set_mode(data, data->mode | STK8312_MODE_ACTIVE);347 if (ret < 0) {348 mutex_unlock(&data->lock);349 return ret;350 }351 ret = stk8312_read_accel(data, chan->address);352 if (ret < 0) {353 stk8312_set_mode(data,354 data->mode & (~STK8312_MODE_ACTIVE));355 mutex_unlock(&data->lock);356 return ret;357 }358 *val = sign_extend32(ret, chan->scan_type.realbits - 1);359 ret = stk8312_set_mode(data,360 data->mode & (~STK8312_MODE_ACTIVE));361 mutex_unlock(&data->lock);362 if (ret < 0)363 return ret;364 return IIO_VAL_INT;365 case IIO_CHAN_INFO_SCALE:366 *val = stk8312_scale_table[data->range - 1][0];367 *val2 = stk8312_scale_table[data->range - 1][1];368 return IIO_VAL_INT_PLUS_MICRO;369 case IIO_CHAN_INFO_SAMP_FREQ:370 *val = stk8312_samp_freq_table[data->sample_rate_idx].val;371 *val2 = stk8312_samp_freq_table[data->sample_rate_idx].val2;372 return IIO_VAL_INT_PLUS_MICRO;373 }374 375 return -EINVAL;376}377 378static int stk8312_write_raw(struct iio_dev *indio_dev,379 struct iio_chan_spec const *chan,380 int val, int val2, long mask)381{382 int i;383 int index = -1;384 int ret;385 struct stk8312_data *data = iio_priv(indio_dev);386 387 switch (mask) {388 case IIO_CHAN_INFO_SCALE:389 for (i = 0; i < ARRAY_SIZE(stk8312_scale_table); i++)390 if (val == stk8312_scale_table[i][0] &&391 val2 == stk8312_scale_table[i][1]) {392 index = i + 1;393 break;394 }395 if (index < 0)396 return -EINVAL;397 398 mutex_lock(&data->lock);399 ret = stk8312_set_range(data, index);400 mutex_unlock(&data->lock);401 402 return ret;403 case IIO_CHAN_INFO_SAMP_FREQ:404 for (i = 0; i < ARRAY_SIZE(stk8312_samp_freq_table); i++)405 if (val == stk8312_samp_freq_table[i].val &&406 val2 == stk8312_samp_freq_table[i].val2) {407 index = i;408 break;409 }410 if (index < 0)411 return -EINVAL;412 mutex_lock(&data->lock);413 ret = stk8312_set_sample_rate(data, index);414 mutex_unlock(&data->lock);415 416 return ret;417 }418 419 return -EINVAL;420}421 422static const struct iio_info stk8312_info = {423 .read_raw = stk8312_read_raw,424 .write_raw = stk8312_write_raw,425 .attrs = &stk8312_attribute_group,426};427 428static irqreturn_t stk8312_trigger_handler(int irq, void *p)429{430 struct iio_poll_func *pf = p;431 struct iio_dev *indio_dev = pf->indio_dev;432 struct stk8312_data *data = iio_priv(indio_dev);433 int bit, ret, i = 0;434 435 mutex_lock(&data->lock);436 /*437 * Do a bulk read if all channels are requested,438 * from 0x00 (XOUT) to 0x02 (ZOUT)439 */440 if (*(indio_dev->active_scan_mask) == STK8312_ALL_CHANNEL_MASK) {441 ret = i2c_smbus_read_i2c_block_data(data->client,442 STK8312_REG_XOUT,443 STK8312_ALL_CHANNEL_SIZE,444 data->scan.chans);445 if (ret < STK8312_ALL_CHANNEL_SIZE) {446 dev_err(&data->client->dev, "register read failed\n");447 mutex_unlock(&data->lock);448 goto err;449 }450 } else {451 iio_for_each_active_channel(indio_dev, bit) {452 ret = stk8312_read_accel(data, bit);453 if (ret < 0) {454 mutex_unlock(&data->lock);455 goto err;456 }457 data->scan.chans[i++] = ret;458 }459 }460 mutex_unlock(&data->lock);461 462 iio_push_to_buffers_with_timestamp(indio_dev, &data->scan,463 pf->timestamp);464err:465 iio_trigger_notify_done(indio_dev->trig);466 467 return IRQ_HANDLED;468}469 470static irqreturn_t stk8312_data_rdy_trig_poll(int irq, void *private)471{472 struct iio_dev *indio_dev = private;473 struct stk8312_data *data = iio_priv(indio_dev);474 475 if (data->dready_trigger_on)476 iio_trigger_poll(data->dready_trig);477 478 return IRQ_HANDLED;479}480 481static int stk8312_buffer_preenable(struct iio_dev *indio_dev)482{483 struct stk8312_data *data = iio_priv(indio_dev);484 485 return stk8312_set_mode(data, data->mode | STK8312_MODE_ACTIVE);486}487 488static int stk8312_buffer_postdisable(struct iio_dev *indio_dev)489{490 struct stk8312_data *data = iio_priv(indio_dev);491 492 return stk8312_set_mode(data, data->mode & (~STK8312_MODE_ACTIVE));493}494 495static const struct iio_buffer_setup_ops stk8312_buffer_setup_ops = {496 .preenable = stk8312_buffer_preenable,497 .postdisable = stk8312_buffer_postdisable,498};499 500static int stk8312_probe(struct i2c_client *client)501{502 int ret;503 struct iio_dev *indio_dev;504 struct stk8312_data *data;505 506 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));507 if (!indio_dev) {508 dev_err(&client->dev, "iio allocation failed!\n");509 return -ENOMEM;510 }511 512 data = iio_priv(indio_dev);513 data->client = client;514 i2c_set_clientdata(client, indio_dev);515 mutex_init(&data->lock);516 517 indio_dev->info = &stk8312_info;518 indio_dev->name = STK8312_DRIVER_NAME;519 indio_dev->modes = INDIO_DIRECT_MODE;520 indio_dev->channels = stk8312_channels;521 indio_dev->num_channels = ARRAY_SIZE(stk8312_channels);522 523 /* A software reset is recommended at power-on */524 ret = i2c_smbus_write_byte_data(data->client, STK8312_REG_RESET, 0x00);525 if (ret < 0) {526 dev_err(&client->dev, "failed to reset sensor\n");527 return ret;528 }529 data->sample_rate_idx = STK8312_SR_400HZ_IDX;530 ret = stk8312_set_range(data, STK8312_RNG_6G);531 if (ret < 0)532 return ret;533 534 ret = stk8312_set_mode(data,535 STK8312_MODE_INT_AH_PP | STK8312_MODE_ACTIVE);536 if (ret < 0)537 return ret;538 539 if (client->irq > 0) {540 ret = devm_request_threaded_irq(&client->dev, client->irq,541 stk8312_data_rdy_trig_poll,542 NULL,543 IRQF_TRIGGER_RISING |544 IRQF_ONESHOT,545 STK8312_IRQ_NAME,546 indio_dev);547 if (ret < 0) {548 dev_err(&client->dev, "request irq %d failed\n",549 client->irq);550 goto err_power_off;551 }552 553 data->dready_trig = devm_iio_trigger_alloc(&client->dev,554 "%s-dev%d",555 indio_dev->name,556 iio_device_id(indio_dev));557 if (!data->dready_trig) {558 ret = -ENOMEM;559 goto err_power_off;560 }561 562 data->dready_trig->ops = &stk8312_trigger_ops;563 iio_trigger_set_drvdata(data->dready_trig, indio_dev);564 ret = iio_trigger_register(data->dready_trig);565 if (ret) {566 dev_err(&client->dev, "iio trigger register failed\n");567 goto err_power_off;568 }569 }570 571 ret = iio_triggered_buffer_setup(indio_dev,572 iio_pollfunc_store_time,573 stk8312_trigger_handler,574 &stk8312_buffer_setup_ops);575 if (ret < 0) {576 dev_err(&client->dev, "iio triggered buffer setup failed\n");577 goto err_trigger_unregister;578 }579 580 ret = iio_device_register(indio_dev);581 if (ret < 0) {582 dev_err(&client->dev, "device_register failed\n");583 goto err_buffer_cleanup;584 }585 586 return 0;587 588err_buffer_cleanup:589 iio_triggered_buffer_cleanup(indio_dev);590err_trigger_unregister:591 if (data->dready_trig)592 iio_trigger_unregister(data->dready_trig);593err_power_off:594 stk8312_set_mode(data, STK8312_MODE_STANDBY);595 return ret;596}597 598static void stk8312_remove(struct i2c_client *client)599{600 struct iio_dev *indio_dev = i2c_get_clientdata(client);601 struct stk8312_data *data = iio_priv(indio_dev);602 603 iio_device_unregister(indio_dev);604 iio_triggered_buffer_cleanup(indio_dev);605 606 if (data->dready_trig)607 iio_trigger_unregister(data->dready_trig);608 609 stk8312_set_mode(data, STK8312_MODE_STANDBY);610}611 612static int stk8312_suspend(struct device *dev)613{614 struct stk8312_data *data;615 616 data = iio_priv(i2c_get_clientdata(to_i2c_client(dev)));617 618 return stk8312_set_mode(data, data->mode & (~STK8312_MODE_ACTIVE));619}620 621static int stk8312_resume(struct device *dev)622{623 struct stk8312_data *data;624 625 data = iio_priv(i2c_get_clientdata(to_i2c_client(dev)));626 627 return stk8312_set_mode(data, data->mode | STK8312_MODE_ACTIVE);628}629 630static DEFINE_SIMPLE_DEV_PM_OPS(stk8312_pm_ops, stk8312_suspend,631 stk8312_resume);632 633static const struct i2c_device_id stk8312_i2c_id[] = {634 /* Deprecated in favour of lowercase form */635 { "STK8312" },636 { "stk8312" },637 {}638};639MODULE_DEVICE_TABLE(i2c, stk8312_i2c_id);640 641static struct i2c_driver stk8312_driver = {642 .driver = {643 .name = STK8312_DRIVER_NAME,644 .pm = pm_sleep_ptr(&stk8312_pm_ops),645 },646 .probe = stk8312_probe,647 .remove = stk8312_remove,648 .id_table = stk8312_i2c_id,649};650 651module_i2c_driver(stk8312_driver);652 653MODULE_AUTHOR("Tiberiu Breana <tiberiu.a.breana@intel.com>");654MODULE_DESCRIPTION("STK8312 3-Axis Accelerometer driver");655MODULE_LICENSE("GPL v2");656