drivers/input/misc/kxtj9.c

   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 function 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         guard(mutex)(&input_dev->mutex);
 318         guard(disable_irq)(&client->irq);
 319
 320         /*
 321          * Set current interval to the greater of the minimum interval or
 322          * the requested interval
 323          */
 324         tj9->last_poll_interval = max(interval, tj9->pdata.min_interval);
 325
 326         kxtj9_update_odr(tj9, tj9->last_poll_interval);
 327
 328         return count;
 329 }
 330
 331 static DEVICE_ATTR(poll, S_IRUGO|S_IWUSR, kxtj9_get_poll, kxtj9_set_poll);
 332
 333 static struct attribute *kxtj9_attrs[] = {
 334         &dev_attr_poll.attr,
 335         NULL
 336 };
 337
 338 static umode_t kxtj9_attr_is_visible(struct kobject *kobj,
 339                                      struct attribute *attr, int n)
 340 {
 341         struct device *dev = kobj_to_dev(kobj);
 342         struct i2c_client *client = to_i2c_client(dev);
 343
 344         return client->irq ? attr->mode : 0;
 345 }
 346
 347 static struct attribute_group kxtj9_group = {
 348         .attrs = kxtj9_attrs,
 349         .is_visible = kxtj9_attr_is_visible,
 350 };
 351 __ATTRIBUTE_GROUPS(kxtj9);
 352
 353 static void kxtj9_poll(struct input_dev *input)
 354 {
 355         struct kxtj9_data *tj9 = input_get_drvdata(input);
 356         unsigned int poll_interval = input_get_poll_interval(input);
 357
 358         kxtj9_report_acceleration_data(tj9);
 359
 360         if (poll_interval != tj9->last_poll_interval) {
 361                 kxtj9_update_odr(tj9, poll_interval);
 362                 tj9->last_poll_interval = poll_interval;
 363         }
 364 }
 365
 366 static void kxtj9_platform_exit(void *data)
 367 {
 368         struct kxtj9_data *tj9 = data;
 369
 370         if (tj9->pdata.exit)
 371                 tj9->pdata.exit();
 372 }
 373
 374 static int kxtj9_verify(struct kxtj9_data *tj9)
 375 {
 376         int retval;
 377
 378         retval = kxtj9_device_power_on(tj9);
 379         if (retval < 0)
 380                 return retval;
 381
 382         retval = i2c_smbus_read_byte_data(tj9->client, WHO_AM_I);
 383         if (retval < 0) {
 384                 dev_err(&tj9->client->dev, "read err int source\n");
 385                 goto out;
 386         }
 387
 388         retval = (retval != 0x07 && retval != 0x08) ? -EIO : 0;
 389
 390 out:
 391         kxtj9_device_power_off(tj9);
 392         return retval;
 393 }
 394
 395 static int kxtj9_probe(struct i2c_client *client)
 396 {
 397         const struct kxtj9_platform_data *pdata =
 398                         dev_get_platdata(&client->dev);
 399         struct kxtj9_data *tj9;
 400         struct input_dev *input_dev;
 401         int err;
 402
 403         if (!i2c_check_functionality(client->adapter,
 404                                 I2C_FUNC_I2C | I2C_FUNC_SMBUS_BYTE_DATA)) {
 405                 dev_err(&client->dev, "client is not i2c capable\n");
 406                 return -ENXIO;
 407         }
 408
 409         if (!pdata) {
 410                 dev_err(&client->dev, "platform data is NULL; exiting\n");
 411                 return -EINVAL;
 412         }
 413
 414         tj9 = devm_kzalloc(&client->dev, sizeof(*tj9), GFP_KERNEL);
 415         if (!tj9) {
 416                 dev_err(&client->dev,
 417                         "failed to allocate memory for module data\n");
 418                 return -ENOMEM;
 419         }
 420
 421         tj9->client = client;
 422         tj9->pdata = *pdata;
 423
 424         if (pdata->init) {
 425                 err = pdata->init();
 426                 if (err < 0)
 427                         return err;
 428         }
 429
 430         err = devm_add_action_or_reset(&client->dev, kxtj9_platform_exit, tj9);
 431         if (err)
 432                 return err;
 433
 434         err = kxtj9_verify(tj9);
 435         if (err < 0) {
 436                 dev_err(&client->dev, "device not recognized\n");
 437                 return err;
 438         }
 439
 440         i2c_set_clientdata(client, tj9);
 441
 442         tj9->ctrl_reg1 = tj9->pdata.res_12bit | tj9->pdata.g_range;
 443         tj9->last_poll_interval = tj9->pdata.init_interval;
 444
 445         input_dev = devm_input_allocate_device(&client->dev);
 446         if (!input_dev) {
 447                 dev_err(&client->dev, "input device allocate failed\n");
 448                 return -ENOMEM;
 449         }
 450
 451         input_set_drvdata(input_dev, tj9);
 452         tj9->input_dev = input_dev;
 453
 454         input_dev->name = "kxtj9_accel";
 455         input_dev->id.bustype = BUS_I2C;
 456
 457         input_dev->open = kxtj9_input_open;
 458         input_dev->close = kxtj9_input_close;
 459
 460         input_set_abs_params(input_dev, ABS_X, -G_MAX, G_MAX, FUZZ, FLAT);
 461         input_set_abs_params(input_dev, ABS_Y, -G_MAX, G_MAX, FUZZ, FLAT);
 462         input_set_abs_params(input_dev, ABS_Z, -G_MAX, G_MAX, FUZZ, FLAT);
 463
 464         if (client->irq <= 0) {
 465                 err = input_setup_polling(input_dev, kxtj9_poll);
 466                 if (err)
 467                         return err;
 468         }
 469
 470         err = input_register_device(input_dev);
 471         if (err) {
 472                 dev_err(&client->dev,
 473                         "unable to register input polled device %s: %d\n",
 474                         input_dev->name, err);
 475                 return err;
 476         }
 477
 478         if (client->irq) {
 479                 /* If in irq mode, populate INT_CTRL_REG1 and enable DRDY. */
 480                 tj9->int_ctrl |= KXTJ9_IEN | KXTJ9_IEA | KXTJ9_IEL;
 481                 tj9->ctrl_reg1 |= DRDYE;
 482
 483                 err = devm_request_threaded_irq(&client->dev, client->irq,
 484                                                 NULL, kxtj9_isr,
 485                                                 IRQF_TRIGGER_RISING |
 486                                                         IRQF_ONESHOT,
 487                                                 "kxtj9-irq", tj9);
 488                 if (err) {
 489                         dev_err(&client->dev, "request irq 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         guard(mutex)(&input_dev->mutex);
 504
 505         if (input_device_enabled(input_dev))
 506                 kxtj9_disable(tj9);
 507
 508         return 0;
 509 }
 510
 511 static int kxtj9_resume(struct device *dev)
 512 {
 513         struct i2c_client *client = to_i2c_client(dev);
 514         struct kxtj9_data *tj9 = i2c_get_clientdata(client);
 515         struct input_dev *input_dev = tj9->input_dev;
 516
 517         guard(mutex)(&input_dev->mutex);
 518
 519         if (input_device_enabled(input_dev))
 520                 kxtj9_enable(tj9);
 521
 522         return 0;
 523 }
 524
 525 static DEFINE_SIMPLE_DEV_PM_OPS(kxtj9_pm_ops, kxtj9_suspend, kxtj9_resume);
 526
 527 static const struct i2c_device_id kxtj9_id[] = {
 528         { NAME },
 529         { }
 530 };
 531
 532 MODULE_DEVICE_TABLE(i2c, kxtj9_id);
 533
 534 static struct i2c_driver kxtj9_driver = {
 535         .driver = {
 536                 .name           = NAME,
 537                 .dev_groups     = kxtj9_groups,
 538                 .pm             = pm_sleep_ptr(&kxtj9_pm_ops),
 539         },
 540         .probe          = kxtj9_probe,
 541         .id_table       = kxtj9_id,
 542 };
 543
 544 module_i2c_driver(kxtj9_driver);
 545
 546 MODULE_DESCRIPTION("KXTJ9 accelerometer driver");
 547 MODULE_AUTHOR("Chris Hudson <chudson@kionix.com>");
 548 MODULE_LICENSE("GPL");