linux/drivers/input/misc/kxtj9.c
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   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 */
  70static 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
  83struct 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
  97static 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
 117static 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
 141static 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
 157static 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
 179static 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
 206static 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
 214static 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
 227static 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
 274fail:
 275        kxtj9_device_power_off(tj9);
 276        return err;
 277}
 278
 279static void kxtj9_disable(struct kxtj9_data *tj9)
 280{
 281        kxtj9_device_power_off(tj9);
 282}
 283
 284static 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
 291static 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
 298static 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
 311static 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) */
 354static 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) */
 364static 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
 396static DEVICE_ATTR(poll, S_IRUGO|S_IWUSR, kxtj9_get_poll, kxtj9_set_poll);
 397
 398static struct attribute *kxtj9_attributes[] = {
 399        &dev_attr_poll.attr,
 400        NULL
 401};
 402
 403static struct attribute_group kxtj9_attribute_group = {
 404        .attrs = kxtj9_attributes
 405};
 406
 407
 408#ifdef CONFIG_INPUT_KXTJ9_POLLED_MODE
 409static 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
 422static 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
 429static 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
 436static 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
 469static 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
 477static inline int kxtj9_setup_polled_device(struct kxtj9_data *tj9)
 478{
 479        return -ENOSYS;
 480}
 481
 482static inline void kxtj9_teardown_polled_device(struct kxtj9_data *tj9)
 483{
 484}
 485
 486#endif
 487
 488static 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
 504out:
 505        kxtj9_device_power_off(tj9);
 506        return retval;
 507}
 508
 509static 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
 586err_free_irq:
 587        free_irq(client->irq, tj9);
 588err_destroy_input:
 589        input_unregister_device(tj9->input_dev);
 590err_pdata_exit:
 591        if (tj9->pdata.exit)
 592                tj9->pdata.exit();
 593err_free_mem:
 594        kfree(tj9);
 595        return err;
 596}
 597
 598static 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
 618static int __maybe_unused kxtj9_suspend(struct device *dev)
 619{
 620        struct i2c_client *client = to_i2c_client(dev);
 621        struct kxtj9_data *tj9 = i2c_get_clientdata(client);
 622        struct input_dev *input_dev = tj9->input_dev;
 623
 624        mutex_lock(&input_dev->mutex);
 625
 626        if (input_dev->users)
 627                kxtj9_disable(tj9);
 628
 629        mutex_unlock(&input_dev->mutex);
 630        return 0;
 631}
 632
 633static int __maybe_unused kxtj9_resume(struct device *dev)
 634{
 635        struct i2c_client *client = to_i2c_client(dev);
 636        struct kxtj9_data *tj9 = i2c_get_clientdata(client);
 637        struct input_dev *input_dev = tj9->input_dev;
 638
 639        mutex_lock(&input_dev->mutex);
 640
 641        if (input_dev->users)
 642                kxtj9_enable(tj9);
 643
 644        mutex_unlock(&input_dev->mutex);
 645        return 0;
 646}
 647
 648static SIMPLE_DEV_PM_OPS(kxtj9_pm_ops, kxtj9_suspend, kxtj9_resume);
 649
 650static const struct i2c_device_id kxtj9_id[] = {
 651        { NAME, 0 },
 652        { },
 653};
 654
 655MODULE_DEVICE_TABLE(i2c, kxtj9_id);
 656
 657static struct i2c_driver kxtj9_driver = {
 658        .driver = {
 659                .name   = NAME,
 660                .pm     = &kxtj9_pm_ops,
 661        },
 662        .probe          = kxtj9_probe,
 663        .remove         = kxtj9_remove,
 664        .id_table       = kxtj9_id,
 665};
 666
 667module_i2c_driver(kxtj9_driver);
 668
 669MODULE_DESCRIPTION("KXTJ9 accelerometer driver");
 670MODULE_AUTHOR("Chris Hudson <chudson@kionix.com>");
 671MODULE_LICENSE("GPL");
 672