drivers/input/touchscreen/bu21013_ts.c

   1 /*
   2  * Copyright (C) ST-Ericsson SA 2010
   3  * Author: Naveen Kumar G <naveen.gaddipati@stericsson.com> for ST-Ericsson
   4  * License terms:GNU General Public License (GPL) version 2
   5  */
   6
   7 #include <linux/kernel.h>
   8 #include <linux/delay.h>
   9 #include <linux/interrupt.h>
  10 #include <linux/i2c.h>
  11 #include <linux/workqueue.h>
  12 #include <linux/input.h>
  13 #include <linux/input/bu21013.h>
  14 #include <linux/slab.h>
  15 #include <linux/regulator/consumer.h>
  16
  17 #define PEN_DOWN_INTR   0
  18 #define MAX_FINGERS     2
  19 #define RESET_DELAY     30
  20 #define PENUP_TIMEOUT   (10)
  21 #define DELTA_MIN       16
  22 #define MASK_BITS       0x03
  23 #define SHIFT_8         8
  24 #define SHIFT_2         2
  25 #define LENGTH_OF_BUFFER        11
  26 #define I2C_RETRY_COUNT 5
  27
  28 #define BU21013_SENSORS_BTN_0_7_REG     0x70
  29 #define BU21013_SENSORS_BTN_8_15_REG    0x71
  30 #define BU21013_SENSORS_BTN_16_23_REG   0x72
  31 #define BU21013_X1_POS_MSB_REG          0x73
  32 #define BU21013_X1_POS_LSB_REG          0x74
  33 #define BU21013_Y1_POS_MSB_REG          0x75
  34 #define BU21013_Y1_POS_LSB_REG          0x76
  35 #define BU21013_X2_POS_MSB_REG          0x77
  36 #define BU21013_X2_POS_LSB_REG          0x78
  37 #define BU21013_Y2_POS_MSB_REG          0x79
  38 #define BU21013_Y2_POS_LSB_REG          0x7A
  39 #define BU21013_INT_CLR_REG             0xE8
  40 #define BU21013_INT_MODE_REG            0xE9
  41 #define BU21013_GAIN_REG                0xEA
  42 #define BU21013_OFFSET_MODE_REG         0xEB
  43 #define BU21013_XY_EDGE_REG             0xEC
  44 #define BU21013_RESET_REG               0xED
  45 #define BU21013_CALIB_REG               0xEE
  46 #define BU21013_DONE_REG                0xEF
  47 #define BU21013_SENSOR_0_7_REG          0xF0
  48 #define BU21013_SENSOR_8_15_REG         0xF1
  49 #define BU21013_SENSOR_16_23_REG        0xF2
  50 #define BU21013_POS_MODE1_REG           0xF3
  51 #define BU21013_POS_MODE2_REG           0xF4
  52 #define BU21013_CLK_MODE_REG            0xF5
  53 #define BU21013_IDLE_REG                0xFA
  54 #define BU21013_FILTER_REG              0xFB
  55 #define BU21013_TH_ON_REG               0xFC
  56 #define BU21013_TH_OFF_REG              0xFD
  57
  58
  59 #define BU21013_RESET_ENABLE            0x01
  60
  61 #define BU21013_SENSORS_EN_0_7          0x3F
  62 #define BU21013_SENSORS_EN_8_15         0xFC
  63 #define BU21013_SENSORS_EN_16_23        0x1F
  64
  65 #define BU21013_POS_MODE1_0             0x02
  66 #define BU21013_POS_MODE1_1             0x04
  67 #define BU21013_POS_MODE1_2             0x08
  68
  69 #define BU21013_POS_MODE2_ZERO          0x01
  70 #define BU21013_POS_MODE2_AVG1          0x02
  71 #define BU21013_POS_MODE2_AVG2          0x04
  72 #define BU21013_POS_MODE2_EN_XY         0x08
  73 #define BU21013_POS_MODE2_EN_RAW        0x10
  74 #define BU21013_POS_MODE2_MULTI         0x80
  75
  76 #define BU21013_CLK_MODE_DIV            0x01
  77 #define BU21013_CLK_MODE_EXT            0x02
  78 #define BU21013_CLK_MODE_CALIB          0x80
  79
  80 #define BU21013_IDLET_0                 0x01
  81 #define BU21013_IDLET_1                 0x02
  82 #define BU21013_IDLET_2                 0x04
  83 #define BU21013_IDLET_3                 0x08
  84 #define BU21013_IDLE_INTERMIT_EN        0x10
  85
  86 #define BU21013_DELTA_0_6       0x7F
  87 #define BU21013_FILTER_EN       0x80
  88
  89 #define BU21013_INT_MODE_LEVEL  0x00
  90 #define BU21013_INT_MODE_EDGE   0x01
  91
  92 #define BU21013_GAIN_0          0x01
  93 #define BU21013_GAIN_1          0x02
  94 #define BU21013_GAIN_2          0x04
  95
  96 #define BU21013_OFFSET_MODE_DEFAULT     0x00
  97 #define BU21013_OFFSET_MODE_MOVE        0x01
  98 #define BU21013_OFFSET_MODE_DISABLE     0x02
  99
 100 #define BU21013_TH_ON_0         0x01
 101 #define BU21013_TH_ON_1         0x02
 102 #define BU21013_TH_ON_2         0x04
 103 #define BU21013_TH_ON_3         0x08
 104 #define BU21013_TH_ON_4         0x10
 105 #define BU21013_TH_ON_5         0x20
 106 #define BU21013_TH_ON_6         0x40
 107 #define BU21013_TH_ON_7         0x80
 108 #define BU21013_TH_ON_MAX       0xFF
 109
 110 #define BU21013_TH_OFF_0        0x01
 111 #define BU21013_TH_OFF_1        0x02
 112 #define BU21013_TH_OFF_2        0x04
 113 #define BU21013_TH_OFF_3        0x08
 114 #define BU21013_TH_OFF_4        0x10
 115 #define BU21013_TH_OFF_5        0x20
 116 #define BU21013_TH_OFF_6        0x40
 117 #define BU21013_TH_OFF_7        0x80
 118 #define BU21013_TH_OFF_MAX      0xFF
 119
 120 #define BU21013_X_EDGE_0        0x01
 121 #define BU21013_X_EDGE_1        0x02
 122 #define BU21013_X_EDGE_2        0x04
 123 #define BU21013_X_EDGE_3        0x08
 124 #define BU21013_Y_EDGE_0        0x10
 125 #define BU21013_Y_EDGE_1        0x20
 126 #define BU21013_Y_EDGE_2        0x40
 127 #define BU21013_Y_EDGE_3        0x80
 128
 129 #define BU21013_DONE    0x01
 130 #define BU21013_NUMBER_OF_X_SENSORS     (6)
 131 #define BU21013_NUMBER_OF_Y_SENSORS     (11)
 132
 133 #define DRIVER_TP       "bu21013_tp"
 134
 135 /**
 136  * struct bu21013_ts_data - touch panel data structure
 137  * @client: pointer to the i2c client
 138  * @wait: variable to wait_queue_head_t structure
 139  * @touch_stopped: touch stop flag
 140  * @chip: pointer to the touch panel controller
 141  * @in_dev: pointer to the input device structure
 142  * @intr_pin: interrupt pin value
 143  * @regulator: pointer to the Regulator used for touch screen
 144  *
 145  * Touch panel device data structure
 146  */
 147 struct bu21013_ts_data {
 148         struct i2c_client *client;
 149         wait_queue_head_t wait;
 150         bool touch_stopped;
 151         const struct bu21013_platform_device *chip;
 152         struct input_dev *in_dev;
 153         unsigned int intr_pin;
 154         struct regulator *regulator;
 155 };
 156
 157 /**
 158  * bu21013_read_block_data(): read the touch co-ordinates
 159  * @data: bu21013_ts_data structure pointer
 160  * @buf: byte pointer
 161  *
 162  * Read the touch co-ordinates using i2c read block into buffer
 163  * and returns integer.
 164  */
 165 static int bu21013_read_block_data(struct bu21013_ts_data *data, u8 *buf)
 166 {
 167         int ret, i;
 168
 169         for (i = 0; i < I2C_RETRY_COUNT; i++) {
 170                 ret = i2c_smbus_read_i2c_block_data
 171                         (data->client, BU21013_SENSORS_BTN_0_7_REG,
 172                                 LENGTH_OF_BUFFER, buf);
 173                 if (ret == LENGTH_OF_BUFFER)
 174                         return 0;
 175         }
 176         return -EINVAL;
 177 }
 178
 179 /**
 180  * bu21013_do_touch_report(): Get the touch co-ordinates
 181  * @data: bu21013_ts_data structure pointer
 182  *
 183  * Get the touch co-ordinates from touch sensor registers and writes
 184  * into device structure and returns integer.
 185  */
 186 static int bu21013_do_touch_report(struct bu21013_ts_data *data)
 187 {
 188         u8      buf[LENGTH_OF_BUFFER];
 189         unsigned int pos_x[2], pos_y[2];
 190         bool    has_x_sensors, has_y_sensors;
 191         int     finger_down_count = 0;
 192         int     i;
 193
 194         if (data == NULL)
 195                 return -EINVAL;
 196
 197         if (bu21013_read_block_data(data, buf) < 0)
 198                 return -EINVAL;
 199
 200         has_x_sensors = hweight32(buf[0] & BU21013_SENSORS_EN_0_7);
 201         has_y_sensors = hweight32(((buf[1] & BU21013_SENSORS_EN_8_15) |
 202                 ((buf[2] & BU21013_SENSORS_EN_16_23) << SHIFT_8)) >> SHIFT_2);
 203         if (!has_x_sensors || !has_y_sensors)
 204                 return 0;
 205
 206         for (i = 0; i < MAX_FINGERS; i++) {
 207                 const u8 *p = &buf[4 * i + 3];
 208                 unsigned int x = p[0] << SHIFT_2 | (p[1] & MASK_BITS);
 209                 unsigned int y = p[2] << SHIFT_2 | (p[3] & MASK_BITS);
 210                 if (x == 0 || y == 0)
 211                         continue;
 212                 pos_x[finger_down_count] = x;
 213                 pos_y[finger_down_count] = y;
 214                 finger_down_count++;
 215         }
 216
 217         if (finger_down_count) {
 218                 if (finger_down_count == 2 &&
 219                     (abs(pos_x[0] - pos_x[1]) < DELTA_MIN ||
 220                      abs(pos_y[0] - pos_y[1]) < DELTA_MIN)) {
 221                         return 0;
 222                 }
 223
 224                 for (i = 0; i < finger_down_count; i++) {
 225                         if (data->chip->x_flip)
 226                                 pos_x[i] = data->chip->touch_x_max - pos_x[i];
 227                         if (data->chip->y_flip)
 228                                 pos_y[i] = data->chip->touch_y_max - pos_y[i];
 229
 230                         input_report_abs(data->in_dev,
 231                                          ABS_MT_POSITION_X, pos_x[i]);
 232                         input_report_abs(data->in_dev,
 233                                          ABS_MT_POSITION_Y, pos_y[i]);
 234                         input_mt_sync(data->in_dev);
 235                 }
 236         } else
 237                 input_mt_sync(data->in_dev);
 238
 239         input_sync(data->in_dev);
 240
 241         return 0;
 242 }
 243 /**
 244  * bu21013_gpio_irq() - gpio thread function for touch interrupt
 245  * @irq: irq value
 246  * @device_data: void pointer
 247  *
 248  * This gpio thread function for touch interrupt
 249  * and returns irqreturn_t.
 250  */
 251 static irqreturn_t bu21013_gpio_irq(int irq, void *device_data)
 252 {
 253         struct bu21013_ts_data *data = device_data;
 254         struct i2c_client *i2c = data->client;
 255         int retval;
 256
 257         do {
 258                 retval = bu21013_do_touch_report(data);
 259                 if (retval < 0) {
 260                         dev_err(&i2c->dev, "bu21013_do_touch_report failed\n");
 261                         return IRQ_NONE;
 262                 }
 263
 264                 data->intr_pin = data->chip->irq_read_val();
 265                 if (data->intr_pin == PEN_DOWN_INTR)
 266                         wait_event_timeout(data->wait, data->touch_stopped,
 267                                            msecs_to_jiffies(2));
 268         } while (!data->intr_pin && !data->touch_stopped);
 269
 270         return IRQ_HANDLED;
 271 }
 272
 273 /**
 274  * bu21013_init_chip() - power on sequence for the bu21013 controller
 275  * @data: device structure pointer
 276  *
 277  * This function is used to power on
 278  * the bu21013 controller and returns integer.
 279  */
 280 static int bu21013_init_chip(struct bu21013_ts_data *data)
 281 {
 282         int retval;
 283         struct i2c_client *i2c = data->client;
 284
 285         retval = i2c_smbus_write_byte_data(i2c, BU21013_RESET_REG,
 286                                         BU21013_RESET_ENABLE);
 287         if (retval < 0) {
 288                 dev_err(&i2c->dev, "BU21013_RESET reg write failed\n");
 289                 return retval;
 290         }
 291         msleep(RESET_DELAY);
 292
 293         retval = i2c_smbus_write_byte_data(i2c, BU21013_SENSOR_0_7_REG,
 294                                         BU21013_SENSORS_EN_0_7);
 295         if (retval < 0) {
 296                 dev_err(&i2c->dev, "BU21013_SENSOR_0_7 reg write failed\n");
 297                 return retval;
 298         }
 299
 300         retval = i2c_smbus_write_byte_data(i2c, BU21013_SENSOR_8_15_REG,
 301                                                 BU21013_SENSORS_EN_8_15);
 302         if (retval < 0) {
 303                 dev_err(&i2c->dev, "BU21013_SENSOR_8_15 reg write failed\n");
 304                 return retval;
 305         }
 306
 307         retval = i2c_smbus_write_byte_data(i2c, BU21013_SENSOR_16_23_REG,
 308                                                 BU21013_SENSORS_EN_16_23);
 309         if (retval < 0) {
 310                 dev_err(&i2c->dev, "BU21013_SENSOR_16_23 reg write failed\n");
 311                 return retval;
 312         }
 313
 314         retval = i2c_smbus_write_byte_data(i2c, BU21013_POS_MODE1_REG,
 315                                 (BU21013_POS_MODE1_0 | BU21013_POS_MODE1_1));
 316         if (retval < 0) {
 317                 dev_err(&i2c->dev, "BU21013_POS_MODE1 reg write failed\n");
 318                 return retval;
 319         }
 320
 321         retval = i2c_smbus_write_byte_data(i2c, BU21013_POS_MODE2_REG,
 322                         (BU21013_POS_MODE2_ZERO | BU21013_POS_MODE2_AVG1 |
 323                         BU21013_POS_MODE2_AVG2 | BU21013_POS_MODE2_EN_RAW |
 324                         BU21013_POS_MODE2_MULTI));
 325         if (retval < 0) {
 326                 dev_err(&i2c->dev, "BU21013_POS_MODE2 reg write failed\n");
 327                 return retval;
 328         }
 329
 330         if (data->chip->ext_clk)
 331                 retval = i2c_smbus_write_byte_data(i2c, BU21013_CLK_MODE_REG,
 332                         (BU21013_CLK_MODE_EXT | BU21013_CLK_MODE_CALIB));
 333         else
 334                 retval = i2c_smbus_write_byte_data(i2c, BU21013_CLK_MODE_REG,
 335                         (BU21013_CLK_MODE_DIV | BU21013_CLK_MODE_CALIB));
 336         if (retval < 0) {
 337                 dev_err(&i2c->dev, "BU21013_CLK_MODE reg write failed\n");
 338                 return retval;
 339         }
 340
 341         retval = i2c_smbus_write_byte_data(i2c, BU21013_IDLE_REG,
 342                                 (BU21013_IDLET_0 | BU21013_IDLE_INTERMIT_EN));
 343         if (retval < 0) {
 344                 dev_err(&i2c->dev, "BU21013_IDLE reg write failed\n");
 345                 return retval;
 346         }
 347
 348         retval = i2c_smbus_write_byte_data(i2c, BU21013_INT_MODE_REG,
 349                                                 BU21013_INT_MODE_LEVEL);
 350         if (retval < 0) {
 351                 dev_err(&i2c->dev, "BU21013_INT_MODE reg write failed\n");
 352                 return retval;
 353         }
 354
 355         retval = i2c_smbus_write_byte_data(i2c, BU21013_FILTER_REG,
 356                                                 (BU21013_DELTA_0_6 |
 357                                                         BU21013_FILTER_EN));
 358         if (retval < 0) {
 359                 dev_err(&i2c->dev, "BU21013_FILTER reg write failed\n");
 360                 return retval;
 361         }
 362
 363         retval = i2c_smbus_write_byte_data(i2c, BU21013_TH_ON_REG,
 364                                         BU21013_TH_ON_5);
 365         if (retval < 0) {
 366                 dev_err(&i2c->dev, "BU21013_TH_ON reg write failed\n");
 367                 return retval;
 368         }
 369
 370         retval = i2c_smbus_write_byte_data(i2c, BU21013_TH_OFF_REG,
 371                                 BU21013_TH_OFF_4 | BU21013_TH_OFF_3);
 372         if (retval < 0) {
 373                 dev_err(&i2c->dev, "BU21013_TH_OFF reg write failed\n");
 374                 return retval;
 375         }
 376
 377         retval = i2c_smbus_write_byte_data(i2c, BU21013_GAIN_REG,
 378                                         (BU21013_GAIN_0 | BU21013_GAIN_1));
 379         if (retval < 0) {
 380                 dev_err(&i2c->dev, "BU21013_GAIN reg write failed\n");
 381                 return retval;
 382         }
 383
 384         retval = i2c_smbus_write_byte_data(i2c, BU21013_OFFSET_MODE_REG,
 385                                         BU21013_OFFSET_MODE_DEFAULT);
 386         if (retval < 0) {
 387                 dev_err(&i2c->dev, "BU21013_OFFSET_MODE reg write failed\n");
 388                 return retval;
 389         }
 390
 391         retval = i2c_smbus_write_byte_data(i2c, BU21013_XY_EDGE_REG,
 392                                 (BU21013_X_EDGE_0 | BU21013_X_EDGE_2 |
 393                                 BU21013_Y_EDGE_1 | BU21013_Y_EDGE_3));
 394         if (retval < 0) {
 395                 dev_err(&i2c->dev, "BU21013_XY_EDGE reg write failed\n");
 396                 return retval;
 397         }
 398
 399         retval = i2c_smbus_write_byte_data(i2c, BU21013_DONE_REG,
 400                                                         BU21013_DONE);
 401         if (retval < 0) {
 402                 dev_err(&i2c->dev, "BU21013_REG_DONE reg write failed\n");
 403                 return retval;
 404         }
 405
 406         return 0;
 407 }
 408
 409 /**
 410  * bu21013_free_irq() - frees IRQ registered for touchscreen
 411  * @bu21013_data: device structure pointer
 412  *
 413  * This function signals interrupt thread to stop processing and
 414  * frees interrupt.
 415  */
 416 static void bu21013_free_irq(struct bu21013_ts_data *bu21013_data)
 417 {
 418         bu21013_data->touch_stopped = true;
 419         wake_up(&bu21013_data->wait);
 420         free_irq(bu21013_data->chip->irq, bu21013_data);
 421 }
 422
 423 /**
 424  * bu21013_probe() - initializes the i2c-client touchscreen driver
 425  * @client: i2c client structure pointer
 426  * @id: i2c device id pointer
 427  *
 428  * This function used to initializes the i2c-client touchscreen
 429  * driver and returns integer.
 430  */
 431 static int __devinit bu21013_probe(struct i2c_client *client,
 432                                         const struct i2c_device_id *id)
 433 {
 434         struct bu21013_ts_data *bu21013_data;
 435         struct input_dev *in_dev;
 436         const struct bu21013_platform_device *pdata =
 437                                         client->dev.platform_data;
 438         int error;
 439
 440         if (!i2c_check_functionality(client->adapter,
 441                                         I2C_FUNC_SMBUS_BYTE_DATA)) {
 442                 dev_err(&client->dev, "i2c smbus byte data not supported\n");
 443                 return -EIO;
 444         }
 445
 446         if (!pdata) {
 447                 dev_err(&client->dev, "platform data not defined\n");
 448                 return -EINVAL;
 449         }
 450
 451         bu21013_data = kzalloc(sizeof(struct bu21013_ts_data), GFP_KERNEL);
 452         in_dev = input_allocate_device();
 453         if (!bu21013_data || !in_dev) {
 454                 dev_err(&client->dev, "device memory alloc failed\n");
 455                 error = -ENOMEM;
 456                 goto err_free_mem;
 457         }
 458
 459         bu21013_data->in_dev = in_dev;
 460         bu21013_data->chip = pdata;
 461         bu21013_data->client = client;
 462
 463         bu21013_data->regulator = regulator_get(&client->dev, "V-TOUCH");
 464         if (IS_ERR(bu21013_data->regulator)) {
 465                 dev_err(&client->dev, "regulator_get failed\n");
 466                 error = PTR_ERR(bu21013_data->regulator);
 467                 goto err_free_mem;
 468         }
 469
 470         error = regulator_enable(bu21013_data->regulator);
 471         if (error < 0) {
 472                 dev_err(&client->dev, "regulator enable failed\n");
 473                 goto err_put_regulator;
 474         }
 475
 476         bu21013_data->touch_stopped = false;
 477         init_waitqueue_head(&bu21013_data->wait);
 478
 479         /* configure the gpio pins */
 480         if (pdata->cs_en) {
 481                 error = pdata->cs_en(pdata->cs_pin);
 482                 if (error < 0) {
 483                         dev_err(&client->dev, "chip init failed\n");
 484                         goto err_disable_regulator;
 485                 }
 486         }
 487
 488         /* configure the touch panel controller */
 489         error = bu21013_init_chip(bu21013_data);
 490         if (error) {
 491                 dev_err(&client->dev, "error in bu21013 config\n");
 492                 goto err_cs_disable;
 493         }
 494
 495         /* register the device to input subsystem */
 496         in_dev->name = DRIVER_TP;
 497         in_dev->id.bustype = BUS_I2C;
 498         in_dev->dev.parent = &client->dev;
 499
 500         __set_bit(EV_SYN, in_dev->evbit);
 501         __set_bit(EV_KEY, in_dev->evbit);
 502         __set_bit(EV_ABS, in_dev->evbit);
 503
 504         input_set_abs_params(in_dev, ABS_MT_POSITION_X, 0,
 505                                                 pdata->touch_x_max, 0, 0);
 506         input_set_abs_params(in_dev, ABS_MT_POSITION_Y, 0,
 507                                                 pdata->touch_y_max, 0, 0);
 508         input_set_drvdata(in_dev, bu21013_data);
 509
 510         error = request_threaded_irq(pdata->irq, NULL, bu21013_gpio_irq,
 511                                      IRQF_TRIGGER_FALLING | IRQF_SHARED,
 512                                      DRIVER_TP, bu21013_data);
 513         if (error) {
 514                 dev_err(&client->dev, "request irq %d failed\n", pdata->irq);
 515                 goto err_cs_disable;
 516         }
 517
 518         error = input_register_device(in_dev);
 519         if (error) {
 520                 dev_err(&client->dev, "failed to register input device\n");
 521                 goto err_free_irq;
 522         }
 523
 524         device_init_wakeup(&client->dev, pdata->wakeup);
 525         i2c_set_clientdata(client, bu21013_data);
 526
 527         return 0;
 528
 529 err_free_irq:
 530         bu21013_free_irq(bu21013_data);
 531 err_cs_disable:
 532         pdata->cs_dis(pdata->cs_pin);
 533 err_disable_regulator:
 534         regulator_disable(bu21013_data->regulator);
 535 err_put_regulator:
 536         regulator_put(bu21013_data->regulator);
 537 err_free_mem:
 538         input_free_device(in_dev);
 539         kfree(bu21013_data);
 540
 541         return error;
 542 }
 543 /**
 544  * bu21013_remove() - removes the i2c-client touchscreen driver
 545  * @client: i2c client structure pointer
 546  *
 547  * This function uses to remove the i2c-client
 548  * touchscreen driver and returns integer.
 549  */
 550 static int __devexit bu21013_remove(struct i2c_client *client)
 551 {
 552         struct bu21013_ts_data *bu21013_data = i2c_get_clientdata(client);
 553
 554         bu21013_free_irq(bu21013_data);
 555
 556         bu21013_data->chip->cs_dis(bu21013_data->chip->cs_pin);
 557
 558         input_unregister_device(bu21013_data->in_dev);
 559
 560         regulator_disable(bu21013_data->regulator);
 561         regulator_put(bu21013_data->regulator);
 562
 563         kfree(bu21013_data);
 564
 565         device_init_wakeup(&client->dev, false);
 566
 567         return 0;
 568 }
 569
 570 #ifdef CONFIG_PM
 571 /**
 572  * bu21013_suspend() - suspend the touch screen controller
 573  * @dev: pointer to device structure
 574  *
 575  * This function is used to suspend the
 576  * touch panel controller and returns integer
 577  */
 578 static int bu21013_suspend(struct device *dev)
 579 {
 580         struct bu21013_ts_data *bu21013_data = dev_get_drvdata(dev);
 581         struct i2c_client *client = bu21013_data->client;
 582
 583         bu21013_data->touch_stopped = true;
 584         if (device_may_wakeup(&client->dev))
 585                 enable_irq_wake(bu21013_data->chip->irq);
 586         else
 587                 disable_irq(bu21013_data->chip->irq);
 588
 589         regulator_disable(bu21013_data->regulator);
 590
 591         return 0;
 592 }
 593
 594 /**
 595  * bu21013_resume() - resume the touch screen controller
 596  * @dev: pointer to device structure
 597  *
 598  * This function is used to resume the touch panel
 599  * controller and returns integer.
 600  */
 601 static int bu21013_resume(struct device *dev)
 602 {
 603         struct bu21013_ts_data *bu21013_data = dev_get_drvdata(dev);
 604         struct i2c_client *client = bu21013_data->client;
 605         int retval;
 606
 607         retval = regulator_enable(bu21013_data->regulator);
 608         if (retval < 0) {
 609                 dev_err(&client->dev, "bu21013 regulator enable failed\n");
 610                 return retval;
 611         }
 612
 613         retval = bu21013_init_chip(bu21013_data);
 614         if (retval < 0) {
 615                 dev_err(&client->dev, "bu21013 controller config failed\n");
 616                 return retval;
 617         }
 618
 619         bu21013_data->touch_stopped = false;
 620
 621         if (device_may_wakeup(&client->dev))
 622                 disable_irq_wake(bu21013_data->chip->irq);
 623         else
 624                 enable_irq(bu21013_data->chip->irq);
 625
 626         return 0;
 627 }
 628
 629 static const struct dev_pm_ops bu21013_dev_pm_ops = {
 630         .suspend = bu21013_suspend,
 631         .resume  = bu21013_resume,
 632 };
 633 #endif
 634
 635 static const struct i2c_device_id bu21013_id[] = {
 636         { DRIVER_TP, 0 },
 637         { }
 638 };
 639 MODULE_DEVICE_TABLE(i2c, bu21013_id);
 640
 641 static struct i2c_driver bu21013_driver = {
 642         .driver = {
 643                 .name   =       DRIVER_TP,
 644                 .owner  =       THIS_MODULE,
 645 #ifdef CONFIG_PM
 646                 .pm     =       &bu21013_dev_pm_ops,
 647 #endif
 648         },
 649         .probe          =       bu21013_probe,
 650         .remove         =       __devexit_p(bu21013_remove),
 651         .id_table       =       bu21013_id,
 652 };
 653
 654 /**
 655  * bu21013_init() - initializes the bu21013 touchscreen driver
 656  *
 657  * This function used to initializes the bu21013
 658  * touchscreen driver and returns integer.
 659  */
 660 static int __init bu21013_init(void)
 661 {
 662         return i2c_add_driver(&bu21013_driver);
 663 }
 664
 665 /**
 666  * bu21013_exit() - de-initializes the bu21013 touchscreen driver
 667  *
 668  * This function uses to de-initializes the bu21013
 669  * touchscreen driver and returns none.
 670  */
 671 static void __exit bu21013_exit(void)
 672 {
 673         i2c_del_driver(&bu21013_driver);
 674 }
 675
 676 module_init(bu21013_init);
 677 module_exit(bu21013_exit);
 678
 679 MODULE_LICENSE("GPL v2");
 680 MODULE_AUTHOR("Naveen Kumar G <naveen.gaddipati@stericsson.com>");
 681 MODULE_DESCRIPTION("bu21013 touch screen controller driver");