1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Copyright (C) 2011 Kionix, Inc. 4 * Written by Chris Hudson <chudson@kionix.com> 5 */ 6 7 #include <linux/delay.h> 8 #include <linux/i2c.h> 9 #include <linux/input.h> 10 #include <linux/interrupt.h> 11 #include <linux/module.h> 12 #include <linux/slab.h> 13 #include <linux/input/kxtj9.h> 14 15 #define NAME "kxtj9" 16 #define G_MAX 8000 17 /* OUTPUT REGISTERS */ 18 #define XOUT_L 0x06 19 #define WHO_AM_I 0x0F 20 /* CONTROL REGISTERS */ 21 #define INT_REL 0x1A 22 #define CTRL_REG1 0x1B 23 #define INT_CTRL1 0x1E 24 #define DATA_CTRL 0x21 25 /* CONTROL REGISTER 1 BITS */ 26 #define PC1_OFF 0x7F 27 #define PC1_ON (1 << 7) 28 /* Data ready funtion enable bit: set during probe if using irq mode */ 29 #define DRDYE (1 << 5) 30 /* DATA CONTROL REGISTER BITS */ 31 #define ODR12_5F 0 32 #define ODR25F 1 33 #define ODR50F 2 34 #define ODR100F 3 35 #define ODR200F 4 36 #define ODR400F 5 37 #define ODR800F 6 38 /* INTERRUPT CONTROL REGISTER 1 BITS */ 39 /* Set these during probe if using irq mode */ 40 #define KXTJ9_IEL (1 << 3) 41 #define KXTJ9_IEA (1 << 4) 42 #define KXTJ9_IEN (1 << 5) 43 /* INPUT_ABS CONSTANTS */ 44 #define FUZZ 3 45 #define FLAT 3 46 /* RESUME STATE INDICES */ 47 #define RES_DATA_CTRL 0 48 #define RES_CTRL_REG1 1 49 #define RES_INT_CTRL1 2 50 #define RESUME_ENTRIES 3 51 52 /* 53 * The following table lists the maximum appropriate poll interval for each 54 * available output data rate. 55 */ 56 static const struct { 57 unsigned int cutoff; 58 u8 mask; 59 } kxtj9_odr_table[] = { 60 { 3, ODR800F }, 61 { 5, ODR400F }, 62 { 10, ODR200F }, 63 { 20, ODR100F }, 64 { 40, ODR50F }, 65 { 80, ODR25F }, 66 { 0, ODR12_5F}, 67 }; 68 69 struct kxtj9_data { 70 struct i2c_client *client; 71 struct kxtj9_platform_data pdata; 72 struct input_dev *input_dev; 73 unsigned int last_poll_interval; 74 u8 shift; 75 u8 ctrl_reg1; 76 u8 data_ctrl; 77 u8 int_ctrl; 78 }; 79 80 static int kxtj9_i2c_read(struct kxtj9_data *tj9, u8 addr, u8 *data, int len) 81 { 82 struct i2c_msg msgs[] = { 83 { 84 .addr = tj9->client->addr, 85 .flags = tj9->client->flags, 86 .len = 1, 87 .buf = &addr, 88 }, 89 { 90 .addr = tj9->client->addr, 91 .flags = tj9->client->flags | I2C_M_RD, 92 .len = len, 93 .buf = data, 94 }, 95 }; 96 97 return i2c_transfer(tj9->client->adapter, msgs, 2); 98 } 99 100 static void kxtj9_report_acceleration_data(struct kxtj9_data *tj9) 101 { 102 s16 acc_data[3]; /* Data bytes from hardware xL, xH, yL, yH, zL, zH */ 103 s16 x, y, z; 104 int err; 105 106 err = kxtj9_i2c_read(tj9, XOUT_L, (u8 *)acc_data, 6); 107 if (err < 0) 108 dev_err(&tj9->client->dev, "accelerometer data read failed\n"); 109 110 x = le16_to_cpu(acc_data[tj9->pdata.axis_map_x]); 111 y = le16_to_cpu(acc_data[tj9->pdata.axis_map_y]); 112 z = le16_to_cpu(acc_data[tj9->pdata.axis_map_z]); 113 114 x >>= tj9->shift; 115 y >>= tj9->shift; 116 z >>= tj9->shift; 117 118 input_report_abs(tj9->input_dev, ABS_X, tj9->pdata.negate_x ? -x : x); 119 input_report_abs(tj9->input_dev, ABS_Y, tj9->pdata.negate_y ? -y : y); 120 input_report_abs(tj9->input_dev, ABS_Z, tj9->pdata.negate_z ? -z : z); 121 input_sync(tj9->input_dev); 122 } 123 124 static irqreturn_t kxtj9_isr(int irq, void *dev) 125 { 126 struct kxtj9_data *tj9 = dev; 127 int err; 128 129 /* data ready is the only possible interrupt type */ 130 kxtj9_report_acceleration_data(tj9); 131 132 err = i2c_smbus_read_byte_data(tj9->client, INT_REL); 133 if (err < 0) 134 dev_err(&tj9->client->dev, 135 "error clearing interrupt status: %d\n", err); 136 137 return IRQ_HANDLED; 138 } 139 140 static int kxtj9_update_g_range(struct kxtj9_data *tj9, u8 new_g_range) 141 { 142 switch (new_g_range) { 143 case KXTJ9_G_2G: 144 tj9->shift = 4; 145 break; 146 case KXTJ9_G_4G: 147 tj9->shift = 3; 148 break; 149 case KXTJ9_G_8G: 150 tj9->shift = 2; 151 break; 152 default: 153 return -EINVAL; 154 } 155 156 tj9->ctrl_reg1 &= 0xe7; 157 tj9->ctrl_reg1 |= new_g_range; 158 159 return 0; 160 } 161 162 static int kxtj9_update_odr(struct kxtj9_data *tj9, unsigned int poll_interval) 163 { 164 int err; 165 int i; 166 167 /* Use the lowest ODR that can support the requested poll interval */ 168 for (i = 0; i < ARRAY_SIZE(kxtj9_odr_table); i++) { 169 tj9->data_ctrl = kxtj9_odr_table[i].mask; 170 if (poll_interval < kxtj9_odr_table[i].cutoff) 171 break; 172 } 173 174 err = i2c_smbus_write_byte_data(tj9->client, CTRL_REG1, 0); 175 if (err < 0) 176 return err; 177 178 err = i2c_smbus_write_byte_data(tj9->client, DATA_CTRL, tj9->data_ctrl); 179 if (err < 0) 180 return err; 181 182 err = i2c_smbus_write_byte_data(tj9->client, CTRL_REG1, tj9->ctrl_reg1); 183 if (err < 0) 184 return err; 185 186 return 0; 187 } 188 189 static int kxtj9_device_power_on(struct kxtj9_data *tj9) 190 { 191 if (tj9->pdata.power_on) 192 return tj9->pdata.power_on(); 193 194 return 0; 195 } 196 197 static void kxtj9_device_power_off(struct kxtj9_data *tj9) 198 { 199 int err; 200 201 tj9->ctrl_reg1 &= PC1_OFF; 202 err = i2c_smbus_write_byte_data(tj9->client, CTRL_REG1, tj9->ctrl_reg1); 203 if (err < 0) 204 dev_err(&tj9->client->dev, "soft power off failed\n"); 205 206 if (tj9->pdata.power_off) 207 tj9->pdata.power_off(); 208 } 209 210 static int kxtj9_enable(struct kxtj9_data *tj9) 211 { 212 int err; 213 214 err = kxtj9_device_power_on(tj9); 215 if (err < 0) 216 return err; 217 218 /* ensure that PC1 is cleared before updating control registers */ 219 err = i2c_smbus_write_byte_data(tj9->client, CTRL_REG1, 0); 220 if (err < 0) 221 return err; 222 223 /* only write INT_CTRL_REG1 if in irq mode */ 224 if (tj9->client->irq) { 225 err = i2c_smbus_write_byte_data(tj9->client, 226 INT_CTRL1, tj9->int_ctrl); 227 if (err < 0) 228 return err; 229 } 230 231 err = kxtj9_update_g_range(tj9, tj9->pdata.g_range); 232 if (err < 0) 233 return err; 234 235 /* turn on outputs */ 236 tj9->ctrl_reg1 |= PC1_ON; 237 err = i2c_smbus_write_byte_data(tj9->client, CTRL_REG1, tj9->ctrl_reg1); 238 if (err < 0) 239 return err; 240 241 err = kxtj9_update_odr(tj9, tj9->last_poll_interval); 242 if (err < 0) 243 return err; 244 245 /* clear initial interrupt if in irq mode */ 246 if (tj9->client->irq) { 247 err = i2c_smbus_read_byte_data(tj9->client, INT_REL); 248 if (err < 0) { 249 dev_err(&tj9->client->dev, 250 "error clearing interrupt: %d\n", err); 251 goto fail; 252 } 253 } 254 255 return 0; 256 257 fail: 258 kxtj9_device_power_off(tj9); 259 return err; 260 } 261 262 static void kxtj9_disable(struct kxtj9_data *tj9) 263 { 264 kxtj9_device_power_off(tj9); 265 } 266 267 static int kxtj9_input_open(struct input_dev *input) 268 { 269 struct kxtj9_data *tj9 = input_get_drvdata(input); 270 271 return kxtj9_enable(tj9); 272 } 273 274 static void kxtj9_input_close(struct input_dev *dev) 275 { 276 struct kxtj9_data *tj9 = input_get_drvdata(dev); 277 278 kxtj9_disable(tj9); 279 } 280 281 /* 282 * When IRQ mode is selected, we need to provide an interface to allow the user 283 * to change the output data rate of the part. For consistency, we are using 284 * the set_poll method, which accepts a poll interval in milliseconds, and then 285 * calls update_odr() while passing this value as an argument. In IRQ mode, the 286 * data outputs will not be read AT the requested poll interval, rather, the 287 * lowest ODR that can support the requested interval. The client application 288 * will be responsible for retrieving data from the input node at the desired 289 * interval. 290 */ 291 292 /* Returns currently selected poll interval (in ms) */ 293 static ssize_t kxtj9_get_poll(struct device *dev, 294 struct device_attribute *attr, char *buf) 295 { 296 struct i2c_client *client = to_i2c_client(dev); 297 struct kxtj9_data *tj9 = i2c_get_clientdata(client); 298 299 return sprintf(buf, "%d\n", tj9->last_poll_interval); 300 } 301 302 /* Allow users to select a new poll interval (in ms) */ 303 static ssize_t kxtj9_set_poll(struct device *dev, struct device_attribute *attr, 304 const char *buf, size_t count) 305 { 306 struct i2c_client *client = to_i2c_client(dev); 307 struct kxtj9_data *tj9 = i2c_get_clientdata(client); 308 struct input_dev *input_dev = tj9->input_dev; 309 unsigned int interval; 310 int error; 311 312 error = kstrtouint(buf, 10, &interval); 313 if (error < 0) 314 return error; 315 316 /* Lock the device to prevent races with open/close (and itself) */ 317 mutex_lock(&input_dev->mutex); 318 319 disable_irq(client->irq); 320 321 /* 322 * Set current interval to the greater of the minimum interval or 323 * the requested interval 324 */ 325 tj9->last_poll_interval = max(interval, tj9->pdata.min_interval); 326 327 kxtj9_update_odr(tj9, tj9->last_poll_interval); 328 329 enable_irq(client->irq); 330 mutex_unlock(&input_dev->mutex); 331 332 return count; 333 } 334 335 static DEVICE_ATTR(poll, S_IRUGO|S_IWUSR, kxtj9_get_poll, kxtj9_set_poll); 336 337 static struct attribute *kxtj9_attributes[] = { 338 &dev_attr_poll.attr, 339 NULL 340 }; 341 342 static struct attribute_group kxtj9_attribute_group = { 343 .attrs = kxtj9_attributes 344 }; 345 346 static void kxtj9_poll(struct input_dev *input) 347 { 348 struct kxtj9_data *tj9 = input_get_drvdata(input); 349 unsigned int poll_interval = input_get_poll_interval(input); 350 351 kxtj9_report_acceleration_data(tj9); 352 353 if (poll_interval != tj9->last_poll_interval) { 354 kxtj9_update_odr(tj9, poll_interval); 355 tj9->last_poll_interval = poll_interval; 356 } 357 } 358 359 static void kxtj9_platform_exit(void *data) 360 { 361 struct kxtj9_data *tj9 = data; 362 363 if (tj9->pdata.exit) 364 tj9->pdata.exit(); 365 } 366 367 static int kxtj9_verify(struct kxtj9_data *tj9) 368 { 369 int retval; 370 371 retval = kxtj9_device_power_on(tj9); 372 if (retval < 0) 373 return retval; 374 375 retval = i2c_smbus_read_byte_data(tj9->client, WHO_AM_I); 376 if (retval < 0) { 377 dev_err(&tj9->client->dev, "read err int source\n"); 378 goto out; 379 } 380 381 retval = (retval != 0x07 && retval != 0x08) ? -EIO : 0; 382 383 out: 384 kxtj9_device_power_off(tj9); 385 return retval; 386 } 387 388 static int kxtj9_probe(struct i2c_client *client) 389 { 390 const struct kxtj9_platform_data *pdata = 391 dev_get_platdata(&client->dev); 392 struct kxtj9_data *tj9; 393 struct input_dev *input_dev; 394 int err; 395 396 if (!i2c_check_functionality(client->adapter, 397 I2C_FUNC_I2C | I2C_FUNC_SMBUS_BYTE_DATA)) { 398 dev_err(&client->dev, "client is not i2c capable\n"); 399 return -ENXIO; 400 } 401 402 if (!pdata) { 403 dev_err(&client->dev, "platform data is NULL; exiting\n"); 404 return -EINVAL; 405 } 406 407 tj9 = devm_kzalloc(&client->dev, sizeof(*tj9), GFP_KERNEL); 408 if (!tj9) { 409 dev_err(&client->dev, 410 "failed to allocate memory for module data\n"); 411 return -ENOMEM; 412 } 413 414 tj9->client = client; 415 tj9->pdata = *pdata; 416 417 if (pdata->init) { 418 err = pdata->init(); 419 if (err < 0) 420 return err; 421 } 422 423 err = devm_add_action_or_reset(&client->dev, kxtj9_platform_exit, tj9); 424 if (err) 425 return err; 426 427 err = kxtj9_verify(tj9); 428 if (err < 0) { 429 dev_err(&client->dev, "device not recognized\n"); 430 return err; 431 } 432 433 i2c_set_clientdata(client, tj9); 434 435 tj9->ctrl_reg1 = tj9->pdata.res_12bit | tj9->pdata.g_range; 436 tj9->last_poll_interval = tj9->pdata.init_interval; 437 438 input_dev = devm_input_allocate_device(&client->dev); 439 if (!input_dev) { 440 dev_err(&client->dev, "input device allocate failed\n"); 441 return -ENOMEM; 442 } 443 444 input_set_drvdata(input_dev, tj9); 445 tj9->input_dev = input_dev; 446 447 input_dev->name = "kxtj9_accel"; 448 input_dev->id.bustype = BUS_I2C; 449 450 input_dev->open = kxtj9_input_open; 451 input_dev->close = kxtj9_input_close; 452 453 input_set_abs_params(input_dev, ABS_X, -G_MAX, G_MAX, FUZZ, FLAT); 454 input_set_abs_params(input_dev, ABS_Y, -G_MAX, G_MAX, FUZZ, FLAT); 455 input_set_abs_params(input_dev, ABS_Z, -G_MAX, G_MAX, FUZZ, FLAT); 456 457 if (client->irq <= 0) { 458 err = input_setup_polling(input_dev, kxtj9_poll); 459 if (err) 460 return err; 461 } 462 463 err = input_register_device(input_dev); 464 if (err) { 465 dev_err(&client->dev, 466 "unable to register input polled device %s: %d\n", 467 input_dev->name, err); 468 return err; 469 } 470 471 if (client->irq) { 472 /* If in irq mode, populate INT_CTRL_REG1 and enable DRDY. */ 473 tj9->int_ctrl |= KXTJ9_IEN | KXTJ9_IEA | KXTJ9_IEL; 474 tj9->ctrl_reg1 |= DRDYE; 475 476 err = devm_request_threaded_irq(&client->dev, client->irq, 477 NULL, kxtj9_isr, 478 IRQF_TRIGGER_RISING | 479 IRQF_ONESHOT, 480 "kxtj9-irq", tj9); 481 if (err) { 482 dev_err(&client->dev, "request irq failed: %d\n", err); 483 return err; 484 } 485 486 err = devm_device_add_group(&client->dev, 487 &kxtj9_attribute_group); 488 if (err) { 489 dev_err(&client->dev, "sysfs create failed: %d\n", err); 490 return err; 491 } 492 } 493 494 return 0; 495 } 496 497 static int kxtj9_suspend(struct device *dev) 498 { 499 struct i2c_client *client = to_i2c_client(dev); 500 struct kxtj9_data *tj9 = i2c_get_clientdata(client); 501 struct input_dev *input_dev = tj9->input_dev; 502 503 mutex_lock(&input_dev->mutex); 504 505 if (input_device_enabled(input_dev)) 506 kxtj9_disable(tj9); 507 508 mutex_unlock(&input_dev->mutex); 509 return 0; 510 } 511 512 static int kxtj9_resume(struct device *dev) 513 { 514 struct i2c_client *client = to_i2c_client(dev); 515 struct kxtj9_data *tj9 = i2c_get_clientdata(client); 516 struct input_dev *input_dev = tj9->input_dev; 517 518 mutex_lock(&input_dev->mutex); 519 520 if (input_device_enabled(input_dev)) 521 kxtj9_enable(tj9); 522 523 mutex_unlock(&input_dev->mutex); 524 return 0; 525 } 526 527 static DEFINE_SIMPLE_DEV_PM_OPS(kxtj9_pm_ops, kxtj9_suspend, kxtj9_resume); 528 529 static const struct i2c_device_id kxtj9_id[] = { 530 { NAME, 0 }, 531 { }, 532 }; 533 534 MODULE_DEVICE_TABLE(i2c, kxtj9_id); 535 536 static struct i2c_driver kxtj9_driver = { 537 .driver = { 538 .name = NAME, 539 .pm = pm_sleep_ptr(&kxtj9_pm_ops), 540 }, 541 .probe = kxtj9_probe, 542 .id_table = kxtj9_id, 543 }; 544 545 module_i2c_driver(kxtj9_driver); 546 547 MODULE_DESCRIPTION("KXTJ9 accelerometer driver"); 548 MODULE_AUTHOR("Chris Hudson <chudson@kionix.com>"); 549 MODULE_LICENSE("GPL"); 550