1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Sensortek STK8BA50 3-Axis Accelerometer 4 * 5 * Copyright (c) 2015, Intel Corporation. 6 * 7 * STK8BA50 7-bit I2C address: 0x18. 8 */ 9 10 #include <linux/array_size.h> 11 #include <linux/bitops.h> 12 #include <linux/dev_printk.h> 13 #include <linux/errno.h> 14 #include <linux/i2c.h> 15 #include <linux/interrupt.h> 16 #include <linux/module.h> 17 #include <linux/mutex.h> 18 #include <linux/pm.h> 19 #include <linux/sysfs.h> 20 #include <linux/types.h> 21 22 #include <linux/iio/buffer.h> 23 #include <linux/iio/iio.h> 24 #include <linux/iio/sysfs.h> 25 #include <linux/iio/trigger.h> 26 #include <linux/iio/triggered_buffer.h> 27 #include <linux/iio/trigger_consumer.h> 28 29 #define STK8BA50_REG_XOUT 0x02 30 #define STK8BA50_REG_YOUT 0x04 31 #define STK8BA50_REG_ZOUT 0x06 32 #define STK8BA50_REG_RANGE 0x0F 33 #define STK8BA50_REG_BWSEL 0x10 34 #define STK8BA50_REG_POWMODE 0x11 35 #define STK8BA50_REG_SWRST 0x14 36 #define STK8BA50_REG_INTEN2 0x17 37 #define STK8BA50_REG_INTMAP2 0x1A 38 39 #define STK8BA50_MODE_NORMAL 0 40 #define STK8BA50_MODE_SUSPEND 1 41 #define STK8BA50_MODE_POWERBIT BIT(7) 42 #define STK8BA50_DATA_SHIFT 6 43 #define STK8BA50_RESET_CMD 0xB6 44 #define STK8BA50_SR_1792HZ_IDX 7 45 #define STK8BA50_DREADY_INT_MASK 0x10 46 #define STK8BA50_DREADY_INT_MAP 0x81 47 #define STK8BA50_ALL_CHANNEL_MASK 7 48 #define STK8BA50_ALL_CHANNEL_SIZE 6 49 50 #define STK8BA50_DRIVER_NAME "stk8ba50" 51 52 #define STK8BA50_SCALE_AVAIL "0.0384 0.0767 0.1534 0.3069" 53 54 /* 55 * The accelerometer has four measurement ranges: 56 * +/-2g; +/-4g; +/-8g; +/-16g 57 * 58 * Acceleration values are 10-bit, 2's complement. 59 * Scales are calculated as following: 60 * 61 * scale1 = (2 + 2) * 9.81 / (2^10 - 1) = 0.0384 62 * scale2 = (4 + 4) * 9.81 / (2^10 - 1) = 0.0767 63 * etc. 64 * 65 * Scales are stored in this format: 66 * { <register value>, <scale value> } 67 * 68 * Locally, the range is stored as a table index. 69 */ 70 static const struct { 71 u8 reg_val; 72 u32 scale_val; 73 } stk8ba50_scale_table[] = { 74 {3, 38400}, {5, 76700}, {8, 153400}, {12, 306900} 75 }; 76 77 /* Sample rates are stored as { <register value>, <Hz value> } */ 78 static const struct { 79 u8 reg_val; 80 u16 samp_freq; 81 } stk8ba50_samp_freq_table[] = { 82 {0x08, 14}, {0x09, 25}, {0x0A, 56}, {0x0B, 112}, 83 {0x0C, 224}, {0x0D, 448}, {0x0E, 896}, {0x0F, 1792} 84 }; 85 86 /* Used to map scan mask bits to their corresponding channel register. */ 87 static const int stk8ba50_channel_table[] = { 88 STK8BA50_REG_XOUT, 89 STK8BA50_REG_YOUT, 90 STK8BA50_REG_ZOUT 91 }; 92 93 struct stk8ba50_data { 94 struct i2c_client *client; 95 struct mutex lock; 96 int range; 97 u8 sample_rate_idx; 98 struct iio_trigger *dready_trig; 99 bool dready_trigger_on; 100 /* Ensure timestamp is naturally aligned */ 101 struct { 102 s16 chans[3]; 103 aligned_s64 timetamp; 104 } scan; 105 }; 106 107 #define STK8BA50_ACCEL_CHANNEL(index, reg, axis) { \ 108 .type = IIO_ACCEL, \ 109 .address = reg, \ 110 .modified = 1, \ 111 .channel2 = IIO_MOD_##axis, \ 112 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ 113 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \ 114 BIT(IIO_CHAN_INFO_SAMP_FREQ), \ 115 .scan_index = index, \ 116 .scan_type = { \ 117 .sign = 's', \ 118 .realbits = 10, \ 119 .storagebits = 16, \ 120 .shift = STK8BA50_DATA_SHIFT, \ 121 .endianness = IIO_CPU, \ 122 }, \ 123 } 124 125 static const struct iio_chan_spec stk8ba50_channels[] = { 126 STK8BA50_ACCEL_CHANNEL(0, STK8BA50_REG_XOUT, X), 127 STK8BA50_ACCEL_CHANNEL(1, STK8BA50_REG_YOUT, Y), 128 STK8BA50_ACCEL_CHANNEL(2, STK8BA50_REG_ZOUT, Z), 129 IIO_CHAN_SOFT_TIMESTAMP(3), 130 }; 131 132 static IIO_CONST_ATTR(in_accel_scale_available, STK8BA50_SCALE_AVAIL); 133 134 static IIO_CONST_ATTR_SAMP_FREQ_AVAIL("14 25 56 112 224 448 896 1792"); 135 136 static struct attribute *stk8ba50_attributes[] = { 137 &iio_const_attr_in_accel_scale_available.dev_attr.attr, 138 &iio_const_attr_sampling_frequency_available.dev_attr.attr, 139 NULL, 140 }; 141 142 static const struct attribute_group stk8ba50_attribute_group = { 143 .attrs = stk8ba50_attributes 144 }; 145 146 static int stk8ba50_read_accel(struct stk8ba50_data *data, u8 reg) 147 { 148 int ret; 149 struct i2c_client *client = data->client; 150 151 ret = i2c_smbus_read_word_data(client, reg); 152 if (ret < 0) { 153 dev_err(&client->dev, "register read failed\n"); 154 return ret; 155 } 156 157 return ret; 158 } 159 160 static int stk8ba50_data_rdy_trigger_set_state(struct iio_trigger *trig, 161 bool state) 162 { 163 struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig); 164 struct stk8ba50_data *data = iio_priv(indio_dev); 165 int ret; 166 167 if (state) 168 ret = i2c_smbus_write_byte_data(data->client, 169 STK8BA50_REG_INTEN2, STK8BA50_DREADY_INT_MASK); 170 else 171 ret = i2c_smbus_write_byte_data(data->client, 172 STK8BA50_REG_INTEN2, 0x00); 173 174 if (ret < 0) 175 dev_err(&data->client->dev, "failed to set trigger state\n"); 176 else 177 data->dready_trigger_on = state; 178 179 return ret; 180 } 181 182 static const struct iio_trigger_ops stk8ba50_trigger_ops = { 183 .set_trigger_state = stk8ba50_data_rdy_trigger_set_state, 184 }; 185 186 static int stk8ba50_set_power(struct stk8ba50_data *data, bool mode) 187 { 188 int ret; 189 u8 masked_reg; 190 struct i2c_client *client = data->client; 191 192 ret = i2c_smbus_read_byte_data(client, STK8BA50_REG_POWMODE); 193 if (ret < 0) 194 goto exit_err; 195 196 if (mode) 197 masked_reg = ret | STK8BA50_MODE_POWERBIT; 198 else 199 masked_reg = ret & (~STK8BA50_MODE_POWERBIT); 200 201 ret = i2c_smbus_write_byte_data(client, STK8BA50_REG_POWMODE, 202 masked_reg); 203 if (ret < 0) 204 goto exit_err; 205 206 return ret; 207 208 exit_err: 209 dev_err(&client->dev, "failed to change sensor mode\n"); 210 return ret; 211 } 212 213 static int stk8ba50_read_raw(struct iio_dev *indio_dev, 214 struct iio_chan_spec const *chan, 215 int *val, int *val2, long mask) 216 { 217 struct stk8ba50_data *data = iio_priv(indio_dev); 218 int ret; 219 220 switch (mask) { 221 case IIO_CHAN_INFO_RAW: 222 if (iio_buffer_enabled(indio_dev)) 223 return -EBUSY; 224 mutex_lock(&data->lock); 225 ret = stk8ba50_set_power(data, STK8BA50_MODE_NORMAL); 226 if (ret < 0) { 227 mutex_unlock(&data->lock); 228 return -EINVAL; 229 } 230 ret = stk8ba50_read_accel(data, chan->address); 231 if (ret < 0) { 232 stk8ba50_set_power(data, STK8BA50_MODE_SUSPEND); 233 mutex_unlock(&data->lock); 234 return -EINVAL; 235 } 236 *val = sign_extend32(ret >> chan->scan_type.shift, 237 chan->scan_type.realbits - 1); 238 stk8ba50_set_power(data, STK8BA50_MODE_SUSPEND); 239 mutex_unlock(&data->lock); 240 return IIO_VAL_INT; 241 case IIO_CHAN_INFO_SCALE: 242 *val = 0; 243 *val2 = stk8ba50_scale_table[data->range].scale_val; 244 return IIO_VAL_INT_PLUS_MICRO; 245 case IIO_CHAN_INFO_SAMP_FREQ: 246 *val = stk8ba50_samp_freq_table 247 [data->sample_rate_idx].samp_freq; 248 *val2 = 0; 249 return IIO_VAL_INT; 250 } 251 252 return -EINVAL; 253 } 254 255 static int stk8ba50_write_raw(struct iio_dev *indio_dev, 256 struct iio_chan_spec const *chan, 257 int val, int val2, long mask) 258 { 259 int ret; 260 int i; 261 int index = -1; 262 struct stk8ba50_data *data = iio_priv(indio_dev); 263 264 switch (mask) { 265 case IIO_CHAN_INFO_SCALE: 266 if (val != 0) 267 return -EINVAL; 268 269 for (i = 0; i < ARRAY_SIZE(stk8ba50_scale_table); i++) 270 if (val2 == stk8ba50_scale_table[i].scale_val) { 271 index = i; 272 break; 273 } 274 if (index < 0) 275 return -EINVAL; 276 277 ret = i2c_smbus_write_byte_data(data->client, 278 STK8BA50_REG_RANGE, 279 stk8ba50_scale_table[index].reg_val); 280 if (ret < 0) 281 dev_err(&data->client->dev, 282 "failed to set measurement range\n"); 283 else 284 data->range = index; 285 286 return ret; 287 case IIO_CHAN_INFO_SAMP_FREQ: 288 for (i = 0; i < ARRAY_SIZE(stk8ba50_samp_freq_table); i++) 289 if (val == stk8ba50_samp_freq_table[i].samp_freq) { 290 index = i; 291 break; 292 } 293 if (index < 0) 294 return -EINVAL; 295 296 ret = i2c_smbus_write_byte_data(data->client, 297 STK8BA50_REG_BWSEL, 298 stk8ba50_samp_freq_table[index].reg_val); 299 if (ret < 0) 300 dev_err(&data->client->dev, 301 "failed to set sampling rate\n"); 302 else 303 data->sample_rate_idx = index; 304 305 return ret; 306 } 307 308 return -EINVAL; 309 } 310 311 static const struct iio_info stk8ba50_info = { 312 .read_raw = stk8ba50_read_raw, 313 .write_raw = stk8ba50_write_raw, 314 .attrs = &stk8ba50_attribute_group, 315 }; 316 317 static irqreturn_t stk8ba50_trigger_handler(int irq, void *p) 318 { 319 struct iio_poll_func *pf = p; 320 struct iio_dev *indio_dev = pf->indio_dev; 321 struct stk8ba50_data *data = iio_priv(indio_dev); 322 int bit, ret, i = 0; 323 324 mutex_lock(&data->lock); 325 /* 326 * Do a bulk read if all channels are requested, 327 * from 0x02 (XOUT1) to 0x07 (ZOUT2) 328 */ 329 if (*(indio_dev->active_scan_mask) == STK8BA50_ALL_CHANNEL_MASK) { 330 ret = i2c_smbus_read_i2c_block_data(data->client, 331 STK8BA50_REG_XOUT, 332 STK8BA50_ALL_CHANNEL_SIZE, 333 (u8 *)data->scan.chans); 334 if (ret < STK8BA50_ALL_CHANNEL_SIZE) { 335 dev_err(&data->client->dev, "register read failed\n"); 336 goto err; 337 } 338 } else { 339 iio_for_each_active_channel(indio_dev, bit) { 340 ret = stk8ba50_read_accel(data, 341 stk8ba50_channel_table[bit]); 342 if (ret < 0) 343 goto err; 344 345 data->scan.chans[i++] = ret; 346 } 347 } 348 iio_push_to_buffers_with_ts(indio_dev, &data->scan, sizeof(data->scan), 349 pf->timestamp); 350 err: 351 mutex_unlock(&data->lock); 352 iio_trigger_notify_done(indio_dev->trig); 353 354 return IRQ_HANDLED; 355 } 356 357 static irqreturn_t stk8ba50_data_rdy_trig_poll(int irq, void *private) 358 { 359 struct iio_dev *indio_dev = private; 360 struct stk8ba50_data *data = iio_priv(indio_dev); 361 362 if (data->dready_trigger_on) 363 iio_trigger_poll(data->dready_trig); 364 365 return IRQ_HANDLED; 366 } 367 368 static int stk8ba50_buffer_preenable(struct iio_dev *indio_dev) 369 { 370 struct stk8ba50_data *data = iio_priv(indio_dev); 371 372 return stk8ba50_set_power(data, STK8BA50_MODE_NORMAL); 373 } 374 375 static int stk8ba50_buffer_postdisable(struct iio_dev *indio_dev) 376 { 377 struct stk8ba50_data *data = iio_priv(indio_dev); 378 379 return stk8ba50_set_power(data, STK8BA50_MODE_SUSPEND); 380 } 381 382 static const struct iio_buffer_setup_ops stk8ba50_buffer_setup_ops = { 383 .preenable = stk8ba50_buffer_preenable, 384 .postdisable = stk8ba50_buffer_postdisable, 385 }; 386 387 static int stk8ba50_probe(struct i2c_client *client) 388 { 389 int ret; 390 struct iio_dev *indio_dev; 391 struct stk8ba50_data *data; 392 393 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data)); 394 if (!indio_dev) 395 return -ENOMEM; 396 397 data = iio_priv(indio_dev); 398 data->client = client; 399 i2c_set_clientdata(client, indio_dev); 400 mutex_init(&data->lock); 401 402 indio_dev->info = &stk8ba50_info; 403 indio_dev->name = STK8BA50_DRIVER_NAME; 404 indio_dev->modes = INDIO_DIRECT_MODE; 405 indio_dev->channels = stk8ba50_channels; 406 indio_dev->num_channels = ARRAY_SIZE(stk8ba50_channels); 407 408 /* Reset all registers on startup */ 409 ret = i2c_smbus_write_byte_data(client, 410 STK8BA50_REG_SWRST, STK8BA50_RESET_CMD); 411 if (ret < 0) { 412 dev_err(&client->dev, "failed to reset sensor\n"); 413 goto err_power_off; 414 } 415 416 /* The default range is +/-2g */ 417 data->range = 0; 418 419 /* The default sampling rate is 1792 Hz (maximum) */ 420 data->sample_rate_idx = STK8BA50_SR_1792HZ_IDX; 421 422 /* Set up interrupts */ 423 ret = i2c_smbus_write_byte_data(client, 424 STK8BA50_REG_INTEN2, STK8BA50_DREADY_INT_MASK); 425 if (ret < 0) { 426 dev_err(&client->dev, "failed to set up interrupts\n"); 427 goto err_power_off; 428 } 429 ret = i2c_smbus_write_byte_data(client, 430 STK8BA50_REG_INTMAP2, STK8BA50_DREADY_INT_MAP); 431 if (ret < 0) { 432 dev_err(&client->dev, "failed to set up interrupts\n"); 433 goto err_power_off; 434 } 435 436 if (client->irq > 0) { 437 ret = devm_request_irq(&client->dev, client->irq, 438 stk8ba50_data_rdy_trig_poll, 439 IRQF_TRIGGER_RISING | IRQF_NO_THREAD, 440 "stk8ba50_event", indio_dev); 441 if (ret) 442 goto err_power_off; 443 444 data->dready_trig = devm_iio_trigger_alloc(&client->dev, 445 "%s-dev%d", 446 indio_dev->name, 447 iio_device_id(indio_dev)); 448 if (!data->dready_trig) { 449 ret = -ENOMEM; 450 goto err_power_off; 451 } 452 453 data->dready_trig->ops = &stk8ba50_trigger_ops; 454 iio_trigger_set_drvdata(data->dready_trig, indio_dev); 455 ret = iio_trigger_register(data->dready_trig); 456 if (ret) { 457 dev_err(&client->dev, "iio trigger register failed\n"); 458 goto err_power_off; 459 } 460 } 461 462 ret = iio_triggered_buffer_setup(indio_dev, 463 iio_pollfunc_store_time, 464 stk8ba50_trigger_handler, 465 &stk8ba50_buffer_setup_ops); 466 if (ret < 0) { 467 dev_err(&client->dev, "iio triggered buffer setup failed\n"); 468 goto err_trigger_unregister; 469 } 470 471 ret = iio_device_register(indio_dev); 472 if (ret < 0) { 473 dev_err(&client->dev, "device_register failed\n"); 474 goto err_buffer_cleanup; 475 } 476 477 return ret; 478 479 err_buffer_cleanup: 480 iio_triggered_buffer_cleanup(indio_dev); 481 err_trigger_unregister: 482 if (data->dready_trig) 483 iio_trigger_unregister(data->dready_trig); 484 err_power_off: 485 stk8ba50_set_power(data, STK8BA50_MODE_SUSPEND); 486 return ret; 487 } 488 489 static void stk8ba50_remove(struct i2c_client *client) 490 { 491 struct iio_dev *indio_dev = i2c_get_clientdata(client); 492 struct stk8ba50_data *data = iio_priv(indio_dev); 493 494 iio_device_unregister(indio_dev); 495 iio_triggered_buffer_cleanup(indio_dev); 496 497 if (data->dready_trig) 498 iio_trigger_unregister(data->dready_trig); 499 500 stk8ba50_set_power(data, STK8BA50_MODE_SUSPEND); 501 } 502 503 static int stk8ba50_suspend(struct device *dev) 504 { 505 struct stk8ba50_data *data; 506 507 data = iio_priv(i2c_get_clientdata(to_i2c_client(dev))); 508 509 return stk8ba50_set_power(data, STK8BA50_MODE_SUSPEND); 510 } 511 512 static int stk8ba50_resume(struct device *dev) 513 { 514 struct stk8ba50_data *data; 515 516 data = iio_priv(i2c_get_clientdata(to_i2c_client(dev))); 517 518 return stk8ba50_set_power(data, STK8BA50_MODE_NORMAL); 519 } 520 521 static DEFINE_SIMPLE_DEV_PM_OPS(stk8ba50_pm_ops, stk8ba50_suspend, 522 stk8ba50_resume); 523 524 static const struct i2c_device_id stk8ba50_i2c_id[] = { 525 { .name = "stk8ba50" }, 526 { } 527 }; 528 MODULE_DEVICE_TABLE(i2c, stk8ba50_i2c_id); 529 530 static const struct acpi_device_id stk8ba50_acpi_id[] = { 531 {"STK8BA50", 0}, 532 { } 533 }; 534 535 MODULE_DEVICE_TABLE(acpi, stk8ba50_acpi_id); 536 537 static struct i2c_driver stk8ba50_driver = { 538 .driver = { 539 .name = "stk8ba50", 540 .pm = pm_sleep_ptr(&stk8ba50_pm_ops), 541 .acpi_match_table = stk8ba50_acpi_id, 542 }, 543 .probe = stk8ba50_probe, 544 .remove = stk8ba50_remove, 545 .id_table = stk8ba50_i2c_id, 546 }; 547 548 module_i2c_driver(stk8ba50_driver); 549 550 MODULE_AUTHOR("Tiberiu Breana <tiberiu.a.breana@intel.com>"); 551 MODULE_DESCRIPTION("STK8BA50 3-Axis Accelerometer driver"); 552 MODULE_LICENSE("GPL v2"); 553