drivers/input/misc/kxtj9.c

   1 /*
   2  * Copyright (C) 2011 Kionix, Inc.
   3  * Written by Chris Hudson <chudson@kionix.com>
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License version 2 as
   7  * published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write to the Free Software
  16  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  17  * 02111-1307, USA
  18  */
  19
  20 #include <linux/delay.h>
  21 #include <linux/i2c.h>
  22 #include <linux/input.h>
  23 #include <linux/interrupt.h>
  24 #include <linux/module.h>
  25 #include <linux/slab.h>
  26 #include <linux/input/kxtj9.h>
  27 #include <linux/input-polldev.h>
  28
  29 #define NAME                    "kxtj9"
  30 #define G_MAX                   8000
  31 /* OUTPUT REGISTERS */
  32 #define XOUT_L                  0x06
  33 #define WHO_AM_I                0x0F
  34 /* CONTROL REGISTERS */
  35 #define INT_REL                 0x1A
  36 #define CTRL_REG1               0x1B
  37 #define INT_CTRL1               0x1E
  38 #define DATA_CTRL               0x21
  39 /* CONTROL REGISTER 1 BITS */
  40 #define PC1_OFF                 0x7F
  41 #define PC1_ON                  (1 << 7)
  42 /* Data ready funtion enable bit: set during probe if using irq mode */
  43 #define DRDYE                   (1 << 5)
  44 /* DATA CONTROL REGISTER BITS */
  45 #define ODR12_5F                0
  46 #define ODR25F                  1
  47 #define ODR50F                  2
  48 #define ODR100F         3
  49 #define ODR200F         4
  50 #define ODR400F         5
  51 #define ODR800F         6
  52 /* INTERRUPT CONTROL REGISTER 1 BITS */
  53 /* Set these during probe if using irq mode */
  54 #define KXTJ9_IEL               (1 << 3)
  55 #define KXTJ9_IEA               (1 << 4)
  56 #define KXTJ9_IEN               (1 << 5)
  57 /* INPUT_ABS CONSTANTS */
  58 #define FUZZ                    3
  59 #define FLAT                    3
  60 /* RESUME STATE INDICES */
  61 #define RES_DATA_CTRL           0
  62 #define RES_CTRL_REG1           1
  63 #define RES_INT_CTRL1           2
  64 #define RESUME_ENTRIES          3
  65
  66 /*
  67  * The following table lists the maximum appropriate poll interval for each
  68  * available output data rate.
  69  */
  70 static const struct {
  71         unsigned int cutoff;
  72         u8 mask;
  73 } kxtj9_odr_table[] = {
  74         { 3,    ODR800F },
  75         { 5,    ODR400F },
  76         { 10,   ODR200F },
  77         { 20,   ODR100F },
  78         { 40,   ODR50F  },
  79         { 80,   ODR25F  },
  80         { 0,    ODR12_5F},
  81 };
  82
  83 struct kxtj9_data {
  84         struct i2c_client *client;
  85         struct kxtj9_platform_data pdata;
  86         struct input_dev *input_dev;
  87 #ifdef CONFIG_INPUT_KXTJ9_POLLED_MODE
  88         struct input_polled_dev *poll_dev;
  89 #endif
  90         unsigned int last_poll_interval;
  91         u8 shift;
  92         u8 ctrl_reg1;
  93         u8 data_ctrl;
  94         u8 int_ctrl;
  95 };
  96
  97 static int kxtj9_i2c_read(struct kxtj9_data *tj9, u8 addr, u8 *data, int len)
  98 {
  99         struct i2c_msg msgs[] = {
 100                 {
 101                         .addr = tj9->client->addr,
 102                         .flags = tj9->client->flags,
 103                         .len = 1,
 104                         .buf = &addr,
 105                 },
 106                 {
 107                         .addr = tj9->client->addr,
 108                         .flags = tj9->client->flags | I2C_M_RD,
 109                         .len = len,
 110                         .buf = data,
 111                 },
 112         };
 113
 114         return i2c_transfer(tj9->client->adapter, msgs, 2);
 115 }
 116
 117 static void kxtj9_report_acceleration_data(struct kxtj9_data *tj9)
 118 {
 119         s16 acc_data[3]; /* Data bytes from hardware xL, xH, yL, yH, zL, zH */
 120         s16 x, y, z;
 121         int err;
 122
 123         err = kxtj9_i2c_read(tj9, XOUT_L, (u8 *)acc_data, 6);
 124         if (err < 0)
 125                 dev_err(&tj9->client->dev, "accelerometer data read failed\n");
 126
 127         x = le16_to_cpu(acc_data[tj9->pdata.axis_map_x]);
 128         y = le16_to_cpu(acc_data[tj9->pdata.axis_map_y]);
 129         z = le16_to_cpu(acc_data[tj9->pdata.axis_map_z]);
 130
 131         x >>= tj9->shift;
 132         y >>= tj9->shift;
 133         z >>= tj9->shift;
 134
 135         input_report_abs(tj9->input_dev, ABS_X, tj9->pdata.negate_x ? -x : x);
 136         input_report_abs(tj9->input_dev, ABS_Y, tj9->pdata.negate_y ? -y : y);
 137         input_report_abs(tj9->input_dev, ABS_Z, tj9->pdata.negate_z ? -z : z);
 138         input_sync(tj9->input_dev);
 139 }
 140
 141 static irqreturn_t kxtj9_isr(int irq, void *dev)
 142 {
 143         struct kxtj9_data *tj9 = dev;
 144         int err;
 145
 146         /* data ready is the only possible interrupt type */
 147         kxtj9_report_acceleration_data(tj9);
 148
 149         err = i2c_smbus_read_byte_data(tj9->client, INT_REL);
 150         if (err < 0)
 151                 dev_err(&tj9->client->dev,
 152                         "error clearing interrupt status: %d\n", err);
 153
 154         return IRQ_HANDLED;
 155 }
 156
 157 static int kxtj9_update_g_range(struct kxtj9_data *tj9, u8 new_g_range)
 158 {
 159         switch (new_g_range) {
 160         case KXTJ9_G_2G:
 161                 tj9->shift = 4;
 162                 break;
 163         case KXTJ9_G_4G:
 164                 tj9->shift = 3;
 165                 break;
 166         case KXTJ9_G_8G:
 167                 tj9->shift = 2;
 168                 break;
 169         default:
 170                 return -EINVAL;
 171         }
 172
 173         tj9->ctrl_reg1 &= 0xe7;
 174         tj9->ctrl_reg1 |= new_g_range;
 175
 176         return 0;
 177 }
 178
 179 static int kxtj9_update_odr(struct kxtj9_data *tj9, unsigned int poll_interval)
 180 {
 181         int err;
 182         int i;
 183
 184         /* Use the lowest ODR that can support the requested poll interval */
 185         for (i = 0; i < ARRAY_SIZE(kxtj9_odr_table); i++) {
 186                 tj9->data_ctrl = kxtj9_odr_table[i].mask;
 187                 if (poll_interval < kxtj9_odr_table[i].cutoff)
 188                         break;
 189         }
 190
 191         err = i2c_smbus_write_byte_data(tj9->client, CTRL_REG1, 0);
 192         if (err < 0)
 193                 return err;
 194
 195         err = i2c_smbus_write_byte_data(tj9->client, DATA_CTRL, tj9->data_ctrl);
 196         if (err < 0)
 197                 return err;
 198
 199         err = i2c_smbus_write_byte_data(tj9->client, CTRL_REG1, tj9->ctrl_reg1);
 200         if (err < 0)
 201                 return err;
 202
 203         return 0;
 204 }
 205
 206 static int kxtj9_device_power_on(struct kxtj9_data *tj9)
 207 {
 208         if (tj9->pdata.power_on)
 209                 return tj9->pdata.power_on();
 210
 211         return 0;
 212 }
 213
 214 static void kxtj9_device_power_off(struct kxtj9_data *tj9)
 215 {
 216         int err;
 217
 218         tj9->ctrl_reg1 &= PC1_OFF;
 219         err = i2c_smbus_write_byte_data(tj9->client, CTRL_REG1, tj9->ctrl_reg1);
 220         if (err < 0)
 221                 dev_err(&tj9->client->dev, "soft power off failed\n");
 222
 223         if (tj9->pdata.power_off)
 224                 tj9->pdata.power_off();
 225 }
 226
 227 static int kxtj9_enable(struct kxtj9_data *tj9)
 228 {
 229         int err;
 230
 231         err = kxtj9_device_power_on(tj9);
 232         if (err < 0)
 233                 return err;
 234
 235         /* ensure that PC1 is cleared before updating control registers */
 236         err = i2c_smbus_write_byte_data(tj9->client, CTRL_REG1, 0);
 237         if (err < 0)
 238                 return err;
 239
 240         /* only write INT_CTRL_REG1 if in irq mode */
 241         if (tj9->client->irq) {
 242                 err = i2c_smbus_write_byte_data(tj9->client,
 243                                                 INT_CTRL1, tj9->int_ctrl);
 244                 if (err < 0)
 245                         return err;
 246         }
 247
 248         err = kxtj9_update_g_range(tj9, tj9->pdata.g_range);
 249         if (err < 0)
 250                 return err;
 251
 252         /* turn on outputs */
 253         tj9->ctrl_reg1 |= PC1_ON;
 254         err = i2c_smbus_write_byte_data(tj9->client, CTRL_REG1, tj9->ctrl_reg1);
 255         if (err < 0)
 256                 return err;
 257
 258         err = kxtj9_update_odr(tj9, tj9->last_poll_interval);
 259         if (err < 0)
 260                 return err;
 261
 262         /* clear initial interrupt if in irq mode */
 263         if (tj9->client->irq) {
 264                 err = i2c_smbus_read_byte_data(tj9->client, INT_REL);
 265                 if (err < 0) {
 266                         dev_err(&tj9->client->dev,
 267                                 "error clearing interrupt: %d\n", err);
 268                         goto fail;
 269                 }
 270         }
 271
 272         return 0;
 273
 274 fail:
 275         kxtj9_device_power_off(tj9);
 276         return err;
 277 }
 278
 279 static void kxtj9_disable(struct kxtj9_data *tj9)
 280 {
 281         kxtj9_device_power_off(tj9);
 282 }
 283
 284 static int kxtj9_input_open(struct input_dev *input)
 285 {
 286         struct kxtj9_data *tj9 = input_get_drvdata(input);
 287
 288         return kxtj9_enable(tj9);
 289 }
 290
 291 static void kxtj9_input_close(struct input_dev *dev)
 292 {
 293         struct kxtj9_data *tj9 = input_get_drvdata(dev);
 294
 295         kxtj9_disable(tj9);
 296 }
 297
 298 static void kxtj9_init_input_device(struct kxtj9_data *tj9,
 299                                               struct input_dev *input_dev)
 300 {
 301         __set_bit(EV_ABS, input_dev->evbit);
 302         input_set_abs_params(input_dev, ABS_X, -G_MAX, G_MAX, FUZZ, FLAT);
 303         input_set_abs_params(input_dev, ABS_Y, -G_MAX, G_MAX, FUZZ, FLAT);
 304         input_set_abs_params(input_dev, ABS_Z, -G_MAX, G_MAX, FUZZ, FLAT);
 305
 306         input_dev->name = "kxtj9_accel";
 307         input_dev->id.bustype = BUS_I2C;
 308         input_dev->dev.parent = &tj9->client->dev;
 309 }
 310
 311 static int kxtj9_setup_input_device(struct kxtj9_data *tj9)
 312 {
 313         struct input_dev *input_dev;
 314         int err;
 315
 316         input_dev = input_allocate_device();
 317         if (!input_dev) {
 318                 dev_err(&tj9->client->dev, "input device allocate failed\n");
 319                 return -ENOMEM;
 320         }
 321
 322         tj9->input_dev = input_dev;
 323
 324         input_dev->open = kxtj9_input_open;
 325         input_dev->close = kxtj9_input_close;
 326         input_set_drvdata(input_dev, tj9);
 327
 328         kxtj9_init_input_device(tj9, input_dev);
 329
 330         err = input_register_device(tj9->input_dev);
 331         if (err) {
 332                 dev_err(&tj9->client->dev,
 333                         "unable to register input polled device %s: %d\n",
 334                         tj9->input_dev->name, err);
 335                 input_free_device(tj9->input_dev);
 336                 return err;
 337         }
 338
 339         return 0;
 340 }
 341
 342 /*
 343  * When IRQ mode is selected, we need to provide an interface to allow the user
 344  * to change the output data rate of the part.  For consistency, we are using
 345  * the set_poll method, which accepts a poll interval in milliseconds, and then
 346  * calls update_odr() while passing this value as an argument.  In IRQ mode, the
 347  * data outputs will not be read AT the requested poll interval, rather, the
 348  * lowest ODR that can support the requested interval.  The client application
 349  * will be responsible for retrieving data from the input node at the desired
 350  * interval.
 351  */
 352
 353 /* Returns currently selected poll interval (in ms) */
 354 static ssize_t kxtj9_get_poll(struct device *dev,
 355                                 struct device_attribute *attr, char *buf)
 356 {
 357         struct i2c_client *client = to_i2c_client(dev);
 358         struct kxtj9_data *tj9 = i2c_get_clientdata(client);
 359
 360         return sprintf(buf, "%d\n", tj9->last_poll_interval);
 361 }
 362
 363 /* Allow users to select a new poll interval (in ms) */
 364 static ssize_t kxtj9_set_poll(struct device *dev, struct device_attribute *attr,
 365                                                 const char *buf, size_t count)
 366 {
 367         struct i2c_client *client = to_i2c_client(dev);
 368         struct kxtj9_data *tj9 = i2c_get_clientdata(client);
 369         struct input_dev *input_dev = tj9->input_dev;
 370         unsigned int interval;
 371         int error;
 372
 373         error = kstrtouint(buf, 10, &interval);
 374         if (error < 0)
 375                 return error;
 376
 377         /* Lock the device to prevent races with open/close (and itself) */
 378         mutex_lock(&input_dev->mutex);
 379
 380         disable_irq(client->irq);
 381
 382         /*
 383          * Set current interval to the greater of the minimum interval or
 384          * the requested interval
 385          */
 386         tj9->last_poll_interval = max(interval, tj9->pdata.min_interval);
 387
 388         kxtj9_update_odr(tj9, tj9->last_poll_interval);
 389
 390         enable_irq(client->irq);
 391         mutex_unlock(&input_dev->mutex);
 392
 393         return count;
 394 }
 395
 396 static DEVICE_ATTR(poll, S_IRUGO|S_IWUSR, kxtj9_get_poll, kxtj9_set_poll);
 397
 398 static struct attribute *kxtj9_attributes[] = {
 399         &dev_attr_poll.attr,
 400         NULL
 401 };
 402
 403 static struct attribute_group kxtj9_attribute_group = {
 404         .attrs = kxtj9_attributes
 405 };
 406
 407
 408 #ifdef CONFIG_INPUT_KXTJ9_POLLED_MODE
 409 static void kxtj9_poll(struct input_polled_dev *dev)
 410 {
 411         struct kxtj9_data *tj9 = dev->private;
 412         unsigned int poll_interval = dev->poll_interval;
 413
 414         kxtj9_report_acceleration_data(tj9);
 415
 416         if (poll_interval != tj9->last_poll_interval) {
 417                 kxtj9_update_odr(tj9, poll_interval);
 418                 tj9->last_poll_interval = poll_interval;
 419         }
 420 }
 421
 422 static void kxtj9_polled_input_open(struct input_polled_dev *dev)
 423 {
 424         struct kxtj9_data *tj9 = dev->private;
 425
 426         kxtj9_enable(tj9);
 427 }
 428
 429 static void kxtj9_polled_input_close(struct input_polled_dev *dev)
 430 {
 431         struct kxtj9_data *tj9 = dev->private;
 432
 433         kxtj9_disable(tj9);
 434 }
 435
 436 static int kxtj9_setup_polled_device(struct kxtj9_data *tj9)
 437 {
 438         int err;
 439         struct input_polled_dev *poll_dev;
 440         poll_dev = input_allocate_polled_device();
 441
 442         if (!poll_dev) {
 443                 dev_err(&tj9->client->dev,
 444                         "Failed to allocate polled device\n");
 445                 return -ENOMEM;
 446         }
 447
 448         tj9->poll_dev = poll_dev;
 449         tj9->input_dev = poll_dev->input;
 450
 451         poll_dev->private = tj9;
 452         poll_dev->poll = kxtj9_poll;
 453         poll_dev->open = kxtj9_polled_input_open;
 454         poll_dev->close = kxtj9_polled_input_close;
 455
 456         kxtj9_init_input_device(tj9, poll_dev->input);
 457
 458         err = input_register_polled_device(poll_dev);
 459         if (err) {
 460                 dev_err(&tj9->client->dev,
 461                         "Unable to register polled device, err=%d\n", err);
 462                 input_free_polled_device(poll_dev);
 463                 return err;
 464         }
 465
 466         return 0;
 467 }
 468
 469 static void kxtj9_teardown_polled_device(struct kxtj9_data *tj9)
 470 {
 471         input_unregister_polled_device(tj9->poll_dev);
 472         input_free_polled_device(tj9->poll_dev);
 473 }
 474
 475 #else
 476
 477 static inline int kxtj9_setup_polled_device(struct kxtj9_data *tj9)
 478 {
 479         return -ENOSYS;
 480 }
 481
 482 static inline void kxtj9_teardown_polled_device(struct kxtj9_data *tj9)
 483 {
 484 }
 485
 486 #endif
 487
 488 static int kxtj9_verify(struct kxtj9_data *tj9)
 489 {
 490         int retval;
 491
 492         retval = kxtj9_device_power_on(tj9);
 493         if (retval < 0)
 494                 return retval;
 495
 496         retval = i2c_smbus_read_byte_data(tj9->client, WHO_AM_I);
 497         if (retval < 0) {
 498                 dev_err(&tj9->client->dev, "read err int source\n");
 499                 goto out;
 500         }
 501
 502         retval = (retval != 0x07 && retval != 0x08) ? -EIO : 0;
 503
 504 out:
 505         kxtj9_device_power_off(tj9);
 506         return retval;
 507 }
 508
 509 static int kxtj9_probe(struct i2c_client *client,
 510                                  const struct i2c_device_id *id)
 511 {
 512         const struct kxtj9_platform_data *pdata =
 513                         dev_get_platdata(&client->dev);
 514         struct kxtj9_data *tj9;
 515         int err;
 516
 517         if (!i2c_check_functionality(client->adapter,
 518                                 I2C_FUNC_I2C | I2C_FUNC_SMBUS_BYTE_DATA)) {
 519                 dev_err(&client->dev, "client is not i2c capable\n");
 520                 return -ENXIO;
 521         }
 522
 523         if (!pdata) {
 524                 dev_err(&client->dev, "platform data is NULL; exiting\n");
 525                 return -EINVAL;
 526         }
 527
 528         tj9 = kzalloc(sizeof(*tj9), GFP_KERNEL);
 529         if (!tj9) {
 530                 dev_err(&client->dev,
 531                         "failed to allocate memory for module data\n");
 532                 return -ENOMEM;
 533         }
 534
 535         tj9->client = client;
 536         tj9->pdata = *pdata;
 537
 538         if (pdata->init) {
 539                 err = pdata->init();
 540                 if (err < 0)
 541                         goto err_free_mem;
 542         }
 543
 544         err = kxtj9_verify(tj9);
 545         if (err < 0) {
 546                 dev_err(&client->dev, "device not recognized\n");
 547                 goto err_pdata_exit;
 548         }
 549
 550         i2c_set_clientdata(client, tj9);
 551
 552         tj9->ctrl_reg1 = tj9->pdata.res_12bit | tj9->pdata.g_range;
 553         tj9->last_poll_interval = tj9->pdata.init_interval;
 554
 555         if (client->irq) {
 556                 /* If in irq mode, populate INT_CTRL_REG1 and enable DRDY. */
 557                 tj9->int_ctrl |= KXTJ9_IEN | KXTJ9_IEA | KXTJ9_IEL;
 558                 tj9->ctrl_reg1 |= DRDYE;
 559
 560                 err = kxtj9_setup_input_device(tj9);
 561                 if (err)
 562                         goto err_pdata_exit;
 563
 564                 err = request_threaded_irq(client->irq, NULL, kxtj9_isr,
 565                                            IRQF_TRIGGER_RISING | IRQF_ONESHOT,
 566                                            "kxtj9-irq", tj9);
 567                 if (err) {
 568                         dev_err(&client->dev, "request irq failed: %d\n", err);
 569                         goto err_destroy_input;
 570                 }
 571
 572                 err = sysfs_create_group(&client->dev.kobj, &kxtj9_attribute_group);
 573                 if (err) {
 574                         dev_err(&client->dev, "sysfs create failed: %d\n", err);
 575                         goto err_free_irq;
 576                 }
 577
 578         } else {
 579                 err = kxtj9_setup_polled_device(tj9);
 580                 if (err)
 581                         goto err_pdata_exit;
 582         }
 583
 584         return 0;
 585
 586 err_free_irq:
 587         free_irq(client->irq, tj9);
 588 err_destroy_input:
 589         input_unregister_device(tj9->input_dev);
 590 err_pdata_exit:
 591         if (tj9->pdata.exit)
 592                 tj9->pdata.exit();
 593 err_free_mem:
 594         kfree(tj9);
 595         return err;
 596 }
 597
 598 static int kxtj9_remove(struct i2c_client *client)
 599 {
 600         struct kxtj9_data *tj9 = i2c_get_clientdata(client);
 601
 602         if (client->irq) {
 603                 sysfs_remove_group(&client->dev.kobj, &kxtj9_attribute_group);
 604                 free_irq(client->irq, tj9);
 605                 input_unregister_device(tj9->input_dev);
 606         } else {
 607                 kxtj9_teardown_polled_device(tj9);
 608         }
 609
 610         if (tj9->pdata.exit)
 611                 tj9->pdata.exit();
 612
 613         kfree(tj9);
 614
 615         return 0;
 616 }
 617
 618 #ifdef CONFIG_PM_SLEEP
 619 static int kxtj9_suspend(struct device *dev)
 620 {
 621         struct i2c_client *client = to_i2c_client(dev);
 622         struct kxtj9_data *tj9 = i2c_get_clientdata(client);
 623         struct input_dev *input_dev = tj9->input_dev;
 624
 625         mutex_lock(&input_dev->mutex);
 626
 627         if (input_dev->users)
 628                 kxtj9_disable(tj9);
 629
 630         mutex_unlock(&input_dev->mutex);
 631         return 0;
 632 }
 633
 634 static int kxtj9_resume(struct device *dev)
 635 {
 636         struct i2c_client *client = to_i2c_client(dev);
 637         struct kxtj9_data *tj9 = i2c_get_clientdata(client);
 638         struct input_dev *input_dev = tj9->input_dev;
 639         int retval = 0;
 640
 641         mutex_lock(&input_dev->mutex);
 642
 643         if (input_dev->users)
 644                 kxtj9_enable(tj9);
 645
 646         mutex_unlock(&input_dev->mutex);
 647         return retval;
 648 }
 649 #endif
 650
 651 static SIMPLE_DEV_PM_OPS(kxtj9_pm_ops, kxtj9_suspend, kxtj9_resume);
 652
 653 static const struct i2c_device_id kxtj9_id[] = {
 654         { NAME, 0 },
 655         { },
 656 };
 657
 658 MODULE_DEVICE_TABLE(i2c, kxtj9_id);
 659
 660 static struct i2c_driver kxtj9_driver = {
 661         .driver = {
 662                 .name   = NAME,
 663                 .owner  = THIS_MODULE,
 664                 .pm     = &kxtj9_pm_ops,
 665         },
 666         .probe          = kxtj9_probe,
 667         .remove         = kxtj9_remove,
 668         .id_table       = kxtj9_id,
 669 };
 670
 671 module_i2c_driver(kxtj9_driver);
 672
 673 MODULE_DESCRIPTION("KXTJ9 accelerometer driver");
 674 MODULE_AUTHOR("Chris Hudson <chudson@kionix.com>");
 675 MODULE_LICENSE("GPL");