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");
682