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 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                        const struct i2c_device_id *id)
 390 {
 391         const struct kxtj9_platform_data *pdata =
 392                         dev_get_platdata(&client->dev);
 393         struct kxtj9_data *tj9;
 394         struct input_dev *input_dev;
 395         int err;
 396
 397         if (!i2c_check_functionality(client->adapter,
 398                                 I2C_FUNC_I2C | I2C_FUNC_SMBUS_BYTE_DATA)) {
 399                 dev_err(&client->dev, "client is not i2c capable\n");
 400                 return -ENXIO;
 401         }
 402
 403         if (!pdata) {
 404                 dev_err(&client->dev, "platform data is NULL; exiting\n");
 405                 return -EINVAL;
 406         }
 407
 408         tj9 = devm_kzalloc(&client->dev, sizeof(*tj9), GFP_KERNEL);
 409         if (!tj9) {
 410                 dev_err(&client->dev,
 411                         "failed to allocate memory for module data\n");
 412                 return -ENOMEM;
 413         }
 414
 415         tj9->client = client;
 416         tj9->pdata = *pdata;
 417
 418         if (pdata->init) {
 419                 err = pdata->init();
 420                 if (err < 0)
 421                         return err;
 422         }
 423
 424         err = devm_add_action_or_reset(&client->dev, kxtj9_platform_exit, tj9);
 425         if (err)
 426                 return err;
 427
 428         err = kxtj9_verify(tj9);
 429         if (err < 0) {
 430                 dev_err(&client->dev, "device not recognized\n");
 431                 return err;
 432         }
 433
 434         i2c_set_clientdata(client, tj9);
 435
 436         tj9->ctrl_reg1 = tj9->pdata.res_12bit | tj9->pdata.g_range;
 437         tj9->last_poll_interval = tj9->pdata.init_interval;
 438
 439         input_dev = devm_input_allocate_device(&client->dev);
 440         if (!input_dev) {
 441                 dev_err(&client->dev, "input device allocate failed\n");
 442                 return -ENOMEM;
 443         }
 444
 445         input_set_drvdata(input_dev, tj9);
 446         tj9->input_dev = input_dev;
 447
 448         input_dev->name = "kxtj9_accel";
 449         input_dev->id.bustype = BUS_I2C;
 450
 451         input_dev->open = kxtj9_input_open;
 452         input_dev->close = kxtj9_input_close;
 453
 454         input_set_abs_params(input_dev, ABS_X, -G_MAX, G_MAX, FUZZ, FLAT);
 455         input_set_abs_params(input_dev, ABS_Y, -G_MAX, G_MAX, FUZZ, FLAT);
 456         input_set_abs_params(input_dev, ABS_Z, -G_MAX, G_MAX, FUZZ, FLAT);
 457
 458         if (client->irq <= 0) {
 459                 err = input_setup_polling(input_dev, kxtj9_poll);
 460                 if (err)
 461                         return err;
 462         }
 463
 464         err = input_register_device(input_dev);
 465         if (err) {
 466                 dev_err(&client->dev,
 467                         "unable to register input polled device %s: %d\n",
 468                         input_dev->name, err);
 469                 return err;
 470         }
 471
 472         if (client->irq) {
 473                 /* If in irq mode, populate INT_CTRL_REG1 and enable DRDY. */
 474                 tj9->int_ctrl |= KXTJ9_IEN | KXTJ9_IEA | KXTJ9_IEL;
 475                 tj9->ctrl_reg1 |= DRDYE;
 476
 477                 err = devm_request_threaded_irq(&client->dev, client->irq,
 478                                                 NULL, kxtj9_isr,
 479                                                 IRQF_TRIGGER_RISING |
 480                                                         IRQF_ONESHOT,
 481                                                 "kxtj9-irq", tj9);
 482                 if (err) {
 483                         dev_err(&client->dev, "request irq failed: %d\n", err);
 484                         return err;
 485                 }
 486
 487                 err = devm_device_add_group(&client->dev,
 488                                             &kxtj9_attribute_group);
 489                 if (err) {
 490                         dev_err(&client->dev, "sysfs create failed: %d\n", err);
 491                         return err;
 492                 }
 493         }
 494
 495         return 0;
 496 }
 497
 498 static int __maybe_unused kxtj9_suspend(struct device *dev)
 499 {
 500         struct i2c_client *client = to_i2c_client(dev);
 501         struct kxtj9_data *tj9 = i2c_get_clientdata(client);
 502         struct input_dev *input_dev = tj9->input_dev;
 503
 504         mutex_lock(&input_dev->mutex);
 505
 506         if (input_device_enabled(input_dev))
 507                 kxtj9_disable(tj9);
 508
 509         mutex_unlock(&input_dev->mutex);
 510         return 0;
 511 }
 512
 513 static int __maybe_unused kxtj9_resume(struct device *dev)
 514 {
 515         struct i2c_client *client = to_i2c_client(dev);
 516         struct kxtj9_data *tj9 = i2c_get_clientdata(client);
 517         struct input_dev *input_dev = tj9->input_dev;
 518
 519         mutex_lock(&input_dev->mutex);
 520
 521         if (input_device_enabled(input_dev))
 522                 kxtj9_enable(tj9);
 523
 524         mutex_unlock(&input_dev->mutex);
 525         return 0;
 526 }
 527
 528 static SIMPLE_DEV_PM_OPS(kxtj9_pm_ops, kxtj9_suspend, kxtj9_resume);
 529
 530 static const struct i2c_device_id kxtj9_id[] = {
 531         { NAME, 0 },
 532         { },
 533 };
 534
 535 MODULE_DEVICE_TABLE(i2c, kxtj9_id);
 536
 537 static struct i2c_driver kxtj9_driver = {
 538         .driver = {
 539                 .name   = NAME,
 540                 .pm     = &kxtj9_pm_ops,
 541         },
 542         .probe          = kxtj9_probe,
 543         .id_table       = kxtj9_id,
 544 };
 545
 546 module_i2c_driver(kxtj9_driver);
 547
 548 MODULE_DESCRIPTION("KXTJ9 accelerometer driver");
 549 MODULE_AUTHOR("Chris Hudson <chudson@kionix.com>");
 550 MODULE_LICENSE("GPL");