Merge branch 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git...
[pandora-kernel.git] / 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
16 #define PEN_DOWN_INTR   0
17 #define MAX_FINGERS     2
18 #define RESET_DELAY     30
19 #define PENUP_TIMEOUT   (10)
20 #define DELTA_MIN       16
21 #define MASK_BITS       0x03
22 #define SHIFT_8         8
23 #define SHIFT_2         2
24 #define LENGTH_OF_BUFFER        11
25 #define I2C_RETRY_COUNT 5
26
27 #define BU21013_SENSORS_BTN_0_7_REG     0x70
28 #define BU21013_SENSORS_BTN_8_15_REG    0x71
29 #define BU21013_SENSORS_BTN_16_23_REG   0x72
30 #define BU21013_X1_POS_MSB_REG          0x73
31 #define BU21013_X1_POS_LSB_REG          0x74
32 #define BU21013_Y1_POS_MSB_REG          0x75
33 #define BU21013_Y1_POS_LSB_REG          0x76
34 #define BU21013_X2_POS_MSB_REG          0x77
35 #define BU21013_X2_POS_LSB_REG          0x78
36 #define BU21013_Y2_POS_MSB_REG          0x79
37 #define BU21013_Y2_POS_LSB_REG          0x7A
38 #define BU21013_INT_CLR_REG             0xE8
39 #define BU21013_INT_MODE_REG            0xE9
40 #define BU21013_GAIN_REG                0xEA
41 #define BU21013_OFFSET_MODE_REG         0xEB
42 #define BU21013_XY_EDGE_REG             0xEC
43 #define BU21013_RESET_REG               0xED
44 #define BU21013_CALIB_REG               0xEE
45 #define BU21013_DONE_REG                0xEF
46 #define BU21013_SENSOR_0_7_REG          0xF0
47 #define BU21013_SENSOR_8_15_REG         0xF1
48 #define BU21013_SENSOR_16_23_REG        0xF2
49 #define BU21013_POS_MODE1_REG           0xF3
50 #define BU21013_POS_MODE2_REG           0xF4
51 #define BU21013_CLK_MODE_REG            0xF5
52 #define BU21013_IDLE_REG                0xFA
53 #define BU21013_FILTER_REG              0xFB
54 #define BU21013_TH_ON_REG               0xFC
55 #define BU21013_TH_OFF_REG              0xFD
56
57
58 #define BU21013_RESET_ENABLE            0x01
59
60 #define BU21013_SENSORS_EN_0_7          0x3F
61 #define BU21013_SENSORS_EN_8_15         0xFC
62 #define BU21013_SENSORS_EN_16_23        0x1F
63
64 #define BU21013_POS_MODE1_0             0x02
65 #define BU21013_POS_MODE1_1             0x04
66 #define BU21013_POS_MODE1_2             0x08
67
68 #define BU21013_POS_MODE2_ZERO          0x01
69 #define BU21013_POS_MODE2_AVG1          0x02
70 #define BU21013_POS_MODE2_AVG2          0x04
71 #define BU21013_POS_MODE2_EN_XY         0x08
72 #define BU21013_POS_MODE2_EN_RAW        0x10
73 #define BU21013_POS_MODE2_MULTI         0x80
74
75 #define BU21013_CLK_MODE_DIV            0x01
76 #define BU21013_CLK_MODE_EXT            0x02
77 #define BU21013_CLK_MODE_CALIB          0x80
78
79 #define BU21013_IDLET_0                 0x01
80 #define BU21013_IDLET_1                 0x02
81 #define BU21013_IDLET_2                 0x04
82 #define BU21013_IDLET_3                 0x08
83 #define BU21013_IDLE_INTERMIT_EN        0x10
84
85 #define BU21013_DELTA_0_6       0x7F
86 #define BU21013_FILTER_EN       0x80
87
88 #define BU21013_INT_MODE_LEVEL  0x00
89 #define BU21013_INT_MODE_EDGE   0x01
90
91 #define BU21013_GAIN_0          0x01
92 #define BU21013_GAIN_1          0x02
93 #define BU21013_GAIN_2          0x04
94
95 #define BU21013_OFFSET_MODE_DEFAULT     0x00
96 #define BU21013_OFFSET_MODE_MOVE        0x01
97 #define BU21013_OFFSET_MODE_DISABLE     0x02
98
99 #define BU21013_TH_ON_0         0x01
100 #define BU21013_TH_ON_1         0x02
101 #define BU21013_TH_ON_2         0x04
102 #define BU21013_TH_ON_3         0x08
103 #define BU21013_TH_ON_4         0x10
104 #define BU21013_TH_ON_5         0x20
105 #define BU21013_TH_ON_6         0x40
106 #define BU21013_TH_ON_7         0x80
107 #define BU21013_TH_ON_MAX       0xFF
108
109 #define BU21013_TH_OFF_0        0x01
110 #define BU21013_TH_OFF_1        0x02
111 #define BU21013_TH_OFF_2        0x04
112 #define BU21013_TH_OFF_3        0x08
113 #define BU21013_TH_OFF_4        0x10
114 #define BU21013_TH_OFF_5        0x20
115 #define BU21013_TH_OFF_6        0x40
116 #define BU21013_TH_OFF_7        0x80
117 #define BU21013_TH_OFF_MAX      0xFF
118
119 #define BU21013_X_EDGE_0        0x01
120 #define BU21013_X_EDGE_1        0x02
121 #define BU21013_X_EDGE_2        0x04
122 #define BU21013_X_EDGE_3        0x08
123 #define BU21013_Y_EDGE_0        0x10
124 #define BU21013_Y_EDGE_1        0x20
125 #define BU21013_Y_EDGE_2        0x40
126 #define BU21013_Y_EDGE_3        0x80
127
128 #define BU21013_DONE    0x01
129 #define BU21013_NUMBER_OF_X_SENSORS     (6)
130 #define BU21013_NUMBER_OF_Y_SENSORS     (11)
131
132 #define DRIVER_TP       "bu21013_tp"
133
134 /**
135  * struct bu21013_ts_data - touch panel data structure
136  * @client: pointer to the i2c client
137  * @wait: variable to wait_queue_head_t structure
138  * @touch_stopped: touch stop flag
139  * @chip: pointer to the touch panel controller
140  * @in_dev: pointer to the input device structure
141  * @intr_pin: interrupt pin value
142  *
143  * Touch panel device data structure
144  */
145 struct bu21013_ts_data {
146         struct i2c_client *client;
147         wait_queue_head_t wait;
148         bool touch_stopped;
149         const struct bu21013_platform_device *chip;
150         struct input_dev *in_dev;
151         unsigned int intr_pin;
152 };
153
154 /**
155  * bu21013_read_block_data(): read the touch co-ordinates
156  * @data: bu21013_ts_data structure pointer
157  * @buf: byte pointer
158  *
159  * Read the touch co-ordinates using i2c read block into buffer
160  * and returns integer.
161  */
162 static int bu21013_read_block_data(struct bu21013_ts_data *data, u8 *buf)
163 {
164         int ret, i;
165
166         for (i = 0; i < I2C_RETRY_COUNT; i++) {
167                 ret = i2c_smbus_read_i2c_block_data
168                         (data->client, BU21013_SENSORS_BTN_0_7_REG,
169                                 LENGTH_OF_BUFFER, buf);
170                 if (ret == LENGTH_OF_BUFFER)
171                         return 0;
172         }
173         return -EINVAL;
174 }
175
176 /**
177  * bu21013_do_touch_report(): Get the touch co-ordinates
178  * @data: bu21013_ts_data structure pointer
179  *
180  * Get the touch co-ordinates from touch sensor registers and writes
181  * into device structure and returns integer.
182  */
183 static int bu21013_do_touch_report(struct bu21013_ts_data *data)
184 {
185         u8      buf[LENGTH_OF_BUFFER];
186         unsigned int pos_x[2], pos_y[2];
187         bool    has_x_sensors, has_y_sensors;
188         int     finger_down_count = 0;
189         int     i;
190
191         if (data == NULL)
192                 return -EINVAL;
193
194         if (bu21013_read_block_data(data, buf) < 0)
195                 return -EINVAL;
196
197         has_x_sensors = hweight32(buf[0] & BU21013_SENSORS_EN_0_7);
198         has_y_sensors = hweight32(((buf[1] & BU21013_SENSORS_EN_8_15) |
199                 ((buf[2] & BU21013_SENSORS_EN_16_23) << SHIFT_8)) >> SHIFT_2);
200         if (!has_x_sensors || !has_y_sensors)
201                 return 0;
202
203         for (i = 0; i < MAX_FINGERS; i++) {
204                 const u8 *p = &buf[4 * i + 3];
205                 unsigned int x = p[0] << SHIFT_2 | (p[1] & MASK_BITS);
206                 unsigned int y = p[2] << SHIFT_2 | (p[3] & MASK_BITS);
207                 if (x == 0 || y == 0)
208                         continue;
209                 pos_x[finger_down_count] = x;
210                 pos_y[finger_down_count] = y;
211                 finger_down_count++;
212         }
213
214         if (finger_down_count) {
215                 if (finger_down_count == 2 &&
216                     (abs(pos_x[0] - pos_x[1]) < DELTA_MIN ||
217                      abs(pos_y[0] - pos_y[1]) < DELTA_MIN)) {
218                         return 0;
219                 }
220
221                 for (i = 0; i < finger_down_count; i++) {
222                         if (data->chip->x_flip)
223                                 pos_x[i] = data->chip->touch_x_max - pos_x[i];
224                         if (data->chip->y_flip)
225                                 pos_y[i] = data->chip->touch_y_max - pos_y[i];
226
227                         input_report_abs(data->in_dev,
228                                          ABS_MT_POSITION_X, pos_x[i]);
229                         input_report_abs(data->in_dev,
230                                          ABS_MT_POSITION_Y, pos_y[i]);
231                         input_mt_sync(data->in_dev);
232                 }
233         } else
234                 input_mt_sync(data->in_dev);
235
236         input_sync(data->in_dev);
237
238         return 0;
239 }
240 /**
241  * bu21013_gpio_irq() - gpio thread function for touch interrupt
242  * @irq: irq value
243  * @device_data: void pointer
244  *
245  * This gpio thread function for touch interrupt
246  * and returns irqreturn_t.
247  */
248 static irqreturn_t bu21013_gpio_irq(int irq, void *device_data)
249 {
250         struct bu21013_ts_data *data = device_data;
251         struct i2c_client *i2c = data->client;
252         int retval;
253
254         do {
255                 retval = bu21013_do_touch_report(data);
256                 if (retval < 0) {
257                         dev_err(&i2c->dev, "bu21013_do_touch_report failed\n");
258                         return IRQ_NONE;
259                 }
260
261                 data->intr_pin = data->chip->irq_read_val();
262                 if (data->intr_pin == PEN_DOWN_INTR)
263                         wait_event_timeout(data->wait, data->touch_stopped,
264                                            msecs_to_jiffies(2));
265         } while (!data->intr_pin && !data->touch_stopped);
266
267         return IRQ_HANDLED;
268 }
269
270 /**
271  * bu21013_init_chip() - power on sequence for the bu21013 controller
272  * @data: device structure pointer
273  *
274  * This function is used to power on
275  * the bu21013 controller and returns integer.
276  */
277 static int bu21013_init_chip(struct bu21013_ts_data *data)
278 {
279         int retval;
280         struct i2c_client *i2c = data->client;
281
282         retval = i2c_smbus_write_byte_data(i2c, BU21013_RESET_REG,
283                                         BU21013_RESET_ENABLE);
284         if (retval < 0) {
285                 dev_err(&i2c->dev, "BU21013_RESET reg write failed\n");
286                 return retval;
287         }
288         msleep(RESET_DELAY);
289
290         retval = i2c_smbus_write_byte_data(i2c, BU21013_SENSOR_0_7_REG,
291                                         BU21013_SENSORS_EN_0_7);
292         if (retval < 0) {
293                 dev_err(&i2c->dev, "BU21013_SENSOR_0_7 reg write failed\n");
294                 return retval;
295         }
296
297         retval = i2c_smbus_write_byte_data(i2c, BU21013_SENSOR_8_15_REG,
298                                                 BU21013_SENSORS_EN_8_15);
299         if (retval < 0) {
300                 dev_err(&i2c->dev, "BU21013_SENSOR_8_15 reg write failed\n");
301                 return retval;
302         }
303
304         retval = i2c_smbus_write_byte_data(i2c, BU21013_SENSOR_16_23_REG,
305                                                 BU21013_SENSORS_EN_16_23);
306         if (retval < 0) {
307                 dev_err(&i2c->dev, "BU21013_SENSOR_16_23 reg write failed\n");
308                 return retval;
309         }
310
311         retval = i2c_smbus_write_byte_data(i2c, BU21013_POS_MODE1_REG,
312                                 (BU21013_POS_MODE1_0 | BU21013_POS_MODE1_1));
313         if (retval < 0) {
314                 dev_err(&i2c->dev, "BU21013_POS_MODE1 reg write failed\n");
315                 return retval;
316         }
317
318         retval = i2c_smbus_write_byte_data(i2c, BU21013_POS_MODE2_REG,
319                         (BU21013_POS_MODE2_ZERO | BU21013_POS_MODE2_AVG1 |
320                         BU21013_POS_MODE2_AVG2 | BU21013_POS_MODE2_EN_RAW |
321                         BU21013_POS_MODE2_MULTI));
322         if (retval < 0) {
323                 dev_err(&i2c->dev, "BU21013_POS_MODE2 reg write failed\n");
324                 return retval;
325         }
326
327         if (data->chip->ext_clk)
328                 retval = i2c_smbus_write_byte_data(i2c, BU21013_CLK_MODE_REG,
329                         (BU21013_CLK_MODE_EXT | BU21013_CLK_MODE_CALIB));
330         else
331                 retval = i2c_smbus_write_byte_data(i2c, BU21013_CLK_MODE_REG,
332                         (BU21013_CLK_MODE_DIV | BU21013_CLK_MODE_CALIB));
333         if (retval < 0) {
334                 dev_err(&i2c->dev, "BU21013_CLK_MODE reg write failed\n");
335                 return retval;
336         }
337
338         retval = i2c_smbus_write_byte_data(i2c, BU21013_IDLE_REG,
339                                 (BU21013_IDLET_0 | BU21013_IDLE_INTERMIT_EN));
340         if (retval < 0) {
341                 dev_err(&i2c->dev, "BU21013_IDLE reg write failed\n");
342                 return retval;
343         }
344
345         retval = i2c_smbus_write_byte_data(i2c, BU21013_INT_MODE_REG,
346                                                 BU21013_INT_MODE_LEVEL);
347         if (retval < 0) {
348                 dev_err(&i2c->dev, "BU21013_INT_MODE reg write failed\n");
349                 return retval;
350         }
351
352         retval = i2c_smbus_write_byte_data(i2c, BU21013_FILTER_REG,
353                                                 (BU21013_DELTA_0_6 |
354                                                         BU21013_FILTER_EN));
355         if (retval < 0) {
356                 dev_err(&i2c->dev, "BU21013_FILTER reg write failed\n");
357                 return retval;
358         }
359
360         retval = i2c_smbus_write_byte_data(i2c, BU21013_TH_ON_REG,
361                                         BU21013_TH_ON_5);
362         if (retval < 0) {
363                 dev_err(&i2c->dev, "BU21013_TH_ON reg write failed\n");
364                 return retval;
365         }
366
367         retval = i2c_smbus_write_byte_data(i2c, BU21013_TH_OFF_REG,
368                                 BU21013_TH_OFF_4 || BU21013_TH_OFF_3);
369         if (retval < 0) {
370                 dev_err(&i2c->dev, "BU21013_TH_OFF reg write failed\n");
371                 return retval;
372         }
373
374         retval = i2c_smbus_write_byte_data(i2c, BU21013_GAIN_REG,
375                                         (BU21013_GAIN_0 | BU21013_GAIN_1));
376         if (retval < 0) {
377                 dev_err(&i2c->dev, "BU21013_GAIN reg write failed\n");
378                 return retval;
379         }
380
381         retval = i2c_smbus_write_byte_data(i2c, BU21013_OFFSET_MODE_REG,
382                                         BU21013_OFFSET_MODE_DEFAULT);
383         if (retval < 0) {
384                 dev_err(&i2c->dev, "BU21013_OFFSET_MODE reg write failed\n");
385                 return retval;
386         }
387
388         retval = i2c_smbus_write_byte_data(i2c, BU21013_XY_EDGE_REG,
389                                 (BU21013_X_EDGE_0 | BU21013_X_EDGE_2 |
390                                 BU21013_Y_EDGE_1 | BU21013_Y_EDGE_3));
391         if (retval < 0) {
392                 dev_err(&i2c->dev, "BU21013_XY_EDGE reg write failed\n");
393                 return retval;
394         }
395
396         retval = i2c_smbus_write_byte_data(i2c, BU21013_DONE_REG,
397                                                         BU21013_DONE);
398         if (retval < 0) {
399                 dev_err(&i2c->dev, "BU21013_REG_DONE reg write failed\n");
400                 return retval;
401         }
402
403         return 0;
404 }
405
406 /**
407  * bu21013_free_irq() - frees IRQ registered for touchscreen
408  * @bu21013_data: device structure pointer
409  *
410  * This function signals interrupt thread to stop processing and
411  * frees interrupt.
412  */
413 static void bu21013_free_irq(struct bu21013_ts_data *bu21013_data)
414 {
415         bu21013_data->touch_stopped = true;
416         wake_up(&bu21013_data->wait);
417         free_irq(bu21013_data->chip->irq, bu21013_data);
418 }
419
420 /**
421  * bu21013_probe() - initializes the i2c-client touchscreen driver
422  * @client: i2c client structure pointer
423  * @id: i2c device id pointer
424  *
425  * This function used to initializes the i2c-client touchscreen
426  * driver and returns integer.
427  */
428 static int __devinit bu21013_probe(struct i2c_client *client,
429                                         const struct i2c_device_id *id)
430 {
431         struct bu21013_ts_data *bu21013_data;
432         struct input_dev *in_dev;
433         const struct bu21013_platform_device *pdata =
434                                         client->dev.platform_data;
435         int error;
436
437         if (!i2c_check_functionality(client->adapter,
438                                         I2C_FUNC_SMBUS_BYTE_DATA)) {
439                 dev_err(&client->dev, "i2c smbus byte data not supported\n");
440                 return -EIO;
441         }
442
443         if (!pdata) {
444                 dev_err(&client->dev, "platform data not defined\n");
445                 return -EINVAL;
446         }
447
448         bu21013_data = kzalloc(sizeof(struct bu21013_ts_data), GFP_KERNEL);
449         in_dev = input_allocate_device();
450         if (!bu21013_data || !in_dev) {
451                 dev_err(&client->dev, "device memory alloc failed\n");
452                 error = -ENOMEM;
453                 goto err_free_mem;
454         }
455
456         bu21013_data->in_dev = in_dev;
457         bu21013_data->chip = pdata;
458         bu21013_data->client = client;
459         bu21013_data->touch_stopped = false;
460         init_waitqueue_head(&bu21013_data->wait);
461
462         /* configure the gpio pins */
463         if (pdata->cs_en) {
464                 error = pdata->cs_en(pdata->cs_pin);
465                 if (error < 0) {
466                         dev_err(&client->dev, "chip init failed\n");
467                         goto err_free_mem;
468                 }
469         }
470
471         /* configure the touch panel controller */
472         error = bu21013_init_chip(bu21013_data);
473         if (error) {
474                 dev_err(&client->dev, "error in bu21013 config\n");
475                 goto err_cs_disable;
476         }
477
478         /* register the device to input subsystem */
479         in_dev->name = DRIVER_TP;
480         in_dev->id.bustype = BUS_I2C;
481         in_dev->dev.parent = &client->dev;
482
483         __set_bit(EV_SYN, in_dev->evbit);
484         __set_bit(EV_KEY, in_dev->evbit);
485         __set_bit(EV_ABS, in_dev->evbit);
486
487         input_set_abs_params(in_dev, ABS_MT_POSITION_X, 0,
488                                                 pdata->x_max_res, 0, 0);
489         input_set_abs_params(in_dev, ABS_MT_POSITION_Y, 0,
490                                                 pdata->y_max_res, 0, 0);
491         input_set_drvdata(in_dev, bu21013_data);
492
493         error = request_threaded_irq(pdata->irq, NULL, bu21013_gpio_irq,
494                                      IRQF_TRIGGER_FALLING | IRQF_SHARED,
495                                      DRIVER_TP, bu21013_data);
496         if (error) {
497                 dev_err(&client->dev, "request irq %d failed\n", pdata->irq);
498                 goto err_cs_disable;
499         }
500
501         error = input_register_device(in_dev);
502         if (error) {
503                 dev_err(&client->dev, "failed to register input device\n");
504                 goto err_free_irq;
505         }
506
507         device_init_wakeup(&client->dev, pdata->wakeup);
508         i2c_set_clientdata(client, bu21013_data);
509
510         return 0;
511
512 err_free_irq:
513         bu21013_free_irq(bu21013_data);
514 err_cs_disable:
515         pdata->cs_dis(pdata->cs_pin);
516 err_free_mem:
517         input_free_device(bu21013_data->in_dev);
518         kfree(bu21013_data);
519
520         return error;
521 }
522 /**
523  * bu21013_remove() - removes the i2c-client touchscreen driver
524  * @client: i2c client structure pointer
525  *
526  * This function uses to remove the i2c-client
527  * touchscreen driver and returns integer.
528  */
529 static int __devexit bu21013_remove(struct i2c_client *client)
530 {
531         struct bu21013_ts_data *bu21013_data = i2c_get_clientdata(client);
532
533         bu21013_free_irq(bu21013_data);
534
535         bu21013_data->chip->cs_dis(bu21013_data->chip->cs_pin);
536
537         input_unregister_device(bu21013_data->in_dev);
538         kfree(bu21013_data);
539
540         device_init_wakeup(&client->dev, false);
541
542         return 0;
543 }
544
545 #ifdef CONFIG_PM
546 /**
547  * bu21013_suspend() - suspend the touch screen controller
548  * @dev: pointer to device structure
549  *
550  * This function is used to suspend the
551  * touch panel controller and returns integer
552  */
553 static int bu21013_suspend(struct device *dev)
554 {
555         struct bu21013_ts_data *bu21013_data = dev_get_drvdata(dev);
556         struct i2c_client *client = bu21013_data->client;
557
558         bu21013_data->touch_stopped = true;
559         if (device_may_wakeup(&client->dev))
560                 enable_irq_wake(bu21013_data->chip->irq);
561         else
562                 disable_irq(bu21013_data->chip->irq);
563
564         return 0;
565 }
566
567 /**
568  * bu21013_resume() - resume the touch screen controller
569  * @dev: pointer to device structure
570  *
571  * This function is used to resume the touch panel
572  * controller and returns integer.
573  */
574 static int bu21013_resume(struct device *dev)
575 {
576         struct bu21013_ts_data *bu21013_data = dev_get_drvdata(dev);
577         struct i2c_client *client = bu21013_data->client;
578         int retval;
579
580         retval = bu21013_init_chip(bu21013_data);
581         if (retval < 0) {
582                 dev_err(&client->dev, "bu21013 controller config failed\n");
583                 return retval;
584         }
585
586         bu21013_data->touch_stopped = false;
587
588         if (device_may_wakeup(&client->dev))
589                 disable_irq_wake(bu21013_data->chip->irq);
590         else
591                 enable_irq(bu21013_data->chip->irq);
592
593         return 0;
594 }
595
596 static const struct dev_pm_ops bu21013_dev_pm_ops = {
597         .suspend = bu21013_suspend,
598         .resume  = bu21013_resume,
599 };
600 #endif
601
602 static const struct i2c_device_id bu21013_id[] = {
603         { DRIVER_TP, 0 },
604         { }
605 };
606 MODULE_DEVICE_TABLE(i2c, bu21013_id);
607
608 static struct i2c_driver bu21013_driver = {
609         .driver = {
610                 .name   =       DRIVER_TP,
611                 .owner  =       THIS_MODULE,
612 #ifdef CONFIG_PM
613                 .pm     =       &bu21013_dev_pm_ops,
614 #endif
615         },
616         .probe          =       bu21013_probe,
617         .remove         =       __devexit_p(bu21013_remove),
618         .id_table       =       bu21013_id,
619 };
620
621 /**
622  * bu21013_init() - initializes the bu21013 touchscreen driver
623  *
624  * This function used to initializes the bu21013
625  * touchscreen driver and returns integer.
626  */
627 static int __init bu21013_init(void)
628 {
629         return i2c_add_driver(&bu21013_driver);
630 }
631
632 /**
633  * bu21013_exit() - de-initializes the bu21013 touchscreen driver
634  *
635  * This function uses to de-initializes the bu21013
636  * touchscreen driver and returns none.
637  */
638 static void __exit bu21013_exit(void)
639 {
640         i2c_del_driver(&bu21013_driver);
641 }
642
643 module_init(bu21013_init);
644 module_exit(bu21013_exit);
645
646 MODULE_LICENSE("GPL v2");
647 MODULE_AUTHOR("Naveen Kumar G <naveen.gaddipati@stericsson.com>");
648 MODULE_DESCRIPTION("bu21013 touch screen controller driver");