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 #include <linux/module.h>
17 #include <linux/gpio.h>
18 #include <linux/of.h>
19 #include <linux/of_gpio.h>
20 
21 #define PEN_DOWN_INTR	0
22 #define MAX_FINGERS	2
23 #define RESET_DELAY	30
24 #define PENUP_TIMEOUT	(10)
25 #define DELTA_MIN	16
26 #define MASK_BITS	0x03
27 #define SHIFT_8		8
28 #define SHIFT_2		2
29 #define LENGTH_OF_BUFFER	11
30 #define I2C_RETRY_COUNT	5
31 
32 #define BU21013_SENSORS_BTN_0_7_REG	0x70
33 #define BU21013_SENSORS_BTN_8_15_REG	0x71
34 #define BU21013_SENSORS_BTN_16_23_REG	0x72
35 #define BU21013_X1_POS_MSB_REG		0x73
36 #define BU21013_X1_POS_LSB_REG		0x74
37 #define BU21013_Y1_POS_MSB_REG		0x75
38 #define BU21013_Y1_POS_LSB_REG		0x76
39 #define BU21013_X2_POS_MSB_REG		0x77
40 #define BU21013_X2_POS_LSB_REG		0x78
41 #define BU21013_Y2_POS_MSB_REG		0x79
42 #define BU21013_Y2_POS_LSB_REG		0x7A
43 #define BU21013_INT_CLR_REG		0xE8
44 #define BU21013_INT_MODE_REG		0xE9
45 #define BU21013_GAIN_REG		0xEA
46 #define BU21013_OFFSET_MODE_REG		0xEB
47 #define BU21013_XY_EDGE_REG		0xEC
48 #define BU21013_RESET_REG		0xED
49 #define BU21013_CALIB_REG		0xEE
50 #define BU21013_DONE_REG		0xEF
51 #define BU21013_SENSOR_0_7_REG		0xF0
52 #define BU21013_SENSOR_8_15_REG		0xF1
53 #define BU21013_SENSOR_16_23_REG	0xF2
54 #define BU21013_POS_MODE1_REG		0xF3
55 #define BU21013_POS_MODE2_REG		0xF4
56 #define BU21013_CLK_MODE_REG		0xF5
57 #define BU21013_IDLE_REG		0xFA
58 #define BU21013_FILTER_REG		0xFB
59 #define BU21013_TH_ON_REG		0xFC
60 #define BU21013_TH_OFF_REG		0xFD
61 
62 
63 #define BU21013_RESET_ENABLE		0x01
64 
65 #define BU21013_SENSORS_EN_0_7		0x3F
66 #define BU21013_SENSORS_EN_8_15		0xFC
67 #define BU21013_SENSORS_EN_16_23	0x1F
68 
69 #define BU21013_POS_MODE1_0		0x02
70 #define BU21013_POS_MODE1_1		0x04
71 #define BU21013_POS_MODE1_2		0x08
72 
73 #define BU21013_POS_MODE2_ZERO		0x01
74 #define BU21013_POS_MODE2_AVG1		0x02
75 #define BU21013_POS_MODE2_AVG2		0x04
76 #define BU21013_POS_MODE2_EN_XY		0x08
77 #define BU21013_POS_MODE2_EN_RAW	0x10
78 #define BU21013_POS_MODE2_MULTI		0x80
79 
80 #define BU21013_CLK_MODE_DIV		0x01
81 #define BU21013_CLK_MODE_EXT		0x02
82 #define BU21013_CLK_MODE_CALIB		0x80
83 
84 #define BU21013_IDLET_0			0x01
85 #define BU21013_IDLET_1			0x02
86 #define BU21013_IDLET_2			0x04
87 #define BU21013_IDLET_3			0x08
88 #define BU21013_IDLE_INTERMIT_EN	0x10
89 
90 #define BU21013_DELTA_0_6	0x7F
91 #define BU21013_FILTER_EN	0x80
92 
93 #define BU21013_INT_MODE_LEVEL	0x00
94 #define BU21013_INT_MODE_EDGE	0x01
95 
96 #define BU21013_GAIN_0		0x01
97 #define BU21013_GAIN_1		0x02
98 #define BU21013_GAIN_2		0x04
99 
100 #define BU21013_OFFSET_MODE_DEFAULT	0x00
101 #define BU21013_OFFSET_MODE_MOVE	0x01
102 #define BU21013_OFFSET_MODE_DISABLE	0x02
103 
104 #define BU21013_TH_ON_0		0x01
105 #define BU21013_TH_ON_1		0x02
106 #define BU21013_TH_ON_2		0x04
107 #define BU21013_TH_ON_3		0x08
108 #define BU21013_TH_ON_4		0x10
109 #define BU21013_TH_ON_5		0x20
110 #define BU21013_TH_ON_6		0x40
111 #define BU21013_TH_ON_7		0x80
112 #define BU21013_TH_ON_MAX	0xFF
113 
114 #define BU21013_TH_OFF_0	0x01
115 #define BU21013_TH_OFF_1	0x02
116 #define BU21013_TH_OFF_2	0x04
117 #define BU21013_TH_OFF_3	0x08
118 #define BU21013_TH_OFF_4	0x10
119 #define BU21013_TH_OFF_5	0x20
120 #define BU21013_TH_OFF_6	0x40
121 #define BU21013_TH_OFF_7	0x80
122 #define BU21013_TH_OFF_MAX	0xFF
123 
124 #define BU21013_X_EDGE_0	0x01
125 #define BU21013_X_EDGE_1	0x02
126 #define BU21013_X_EDGE_2	0x04
127 #define BU21013_X_EDGE_3	0x08
128 #define BU21013_Y_EDGE_0	0x10
129 #define BU21013_Y_EDGE_1	0x20
130 #define BU21013_Y_EDGE_2	0x40
131 #define BU21013_Y_EDGE_3	0x80
132 
133 #define BU21013_DONE	0x01
134 #define BU21013_NUMBER_OF_X_SENSORS	(6)
135 #define BU21013_NUMBER_OF_Y_SENSORS	(11)
136 
137 #define DRIVER_TP	"bu21013_tp"
138 
139 /**
140  * struct bu21013_ts_data - touch panel data structure
141  * @client: pointer to the i2c client
142  * @wait: variable to wait_queue_head_t structure
143  * @touch_stopped: touch stop flag
144  * @chip: pointer to the touch panel controller
145  * @in_dev: pointer to the input device structure
146  * @intr_pin: interrupt pin value
147  * @regulator: pointer to the Regulator used for touch screen
148  *
149  * Touch panel device data structure
150  */
151 struct bu21013_ts_data {
152 	struct i2c_client *client;
153 	wait_queue_head_t wait;
154 	const struct bu21013_platform_device *chip;
155 	struct input_dev *in_dev;
156 	struct regulator *regulator;
157 	unsigned int irq;
158 	unsigned int intr_pin;
159 	bool touch_stopped;
160 };
161 
162 /**
163  * bu21013_read_block_data(): read the touch co-ordinates
164  * @data: bu21013_ts_data structure pointer
165  * @buf: byte pointer
166  *
167  * Read the touch co-ordinates using i2c read block into buffer
168  * and returns integer.
169  */
170 static int bu21013_read_block_data(struct bu21013_ts_data *data, u8 *buf)
171 {
172 	int ret, i;
173 
174 	for (i = 0; i < I2C_RETRY_COUNT; i++) {
175 		ret = i2c_smbus_read_i2c_block_data
176 			(data->client, BU21013_SENSORS_BTN_0_7_REG,
177 				LENGTH_OF_BUFFER, buf);
178 		if (ret == LENGTH_OF_BUFFER)
179 			return 0;
180 	}
181 	return -EINVAL;
182 }
183 
184 /**
185  * bu21013_do_touch_report(): Get the touch co-ordinates
186  * @data: bu21013_ts_data structure pointer
187  *
188  * Get the touch co-ordinates from touch sensor registers and writes
189  * into device structure and returns integer.
190  */
191 static int bu21013_do_touch_report(struct bu21013_ts_data *data)
192 {
193 	u8	buf[LENGTH_OF_BUFFER];
194 	unsigned int pos_x[2], pos_y[2];
195 	bool	has_x_sensors, has_y_sensors;
196 	int	finger_down_count = 0;
197 	int	i;
198 
199 	if (data == NULL)
200 		return -EINVAL;
201 
202 	if (bu21013_read_block_data(data, buf) < 0)
203 		return -EINVAL;
204 
205 	has_x_sensors = hweight32(buf[0] & BU21013_SENSORS_EN_0_7);
206 	has_y_sensors = hweight32(((buf[1] & BU21013_SENSORS_EN_8_15) |
207 		((buf[2] & BU21013_SENSORS_EN_16_23) << SHIFT_8)) >> SHIFT_2);
208 	if (!has_x_sensors || !has_y_sensors)
209 		return 0;
210 
211 	for (i = 0; i < MAX_FINGERS; i++) {
212 		const u8 *p = &buf[4 * i + 3];
213 		unsigned int x = p[0] << SHIFT_2 | (p[1] & MASK_BITS);
214 		unsigned int y = p[2] << SHIFT_2 | (p[3] & MASK_BITS);
215 		if (x == 0 || y == 0)
216 			continue;
217 		pos_x[finger_down_count] = x;
218 		pos_y[finger_down_count] = y;
219 		finger_down_count++;
220 	}
221 
222 	if (finger_down_count) {
223 		if (finger_down_count == 2 &&
224 		    (abs(pos_x[0] - pos_x[1]) < DELTA_MIN ||
225 		     abs(pos_y[0] - pos_y[1]) < DELTA_MIN)) {
226 			return 0;
227 		}
228 
229 		for (i = 0; i < finger_down_count; i++) {
230 			if (data->chip->x_flip)
231 				pos_x[i] = data->chip->touch_x_max - pos_x[i];
232 			if (data->chip->y_flip)
233 				pos_y[i] = data->chip->touch_y_max - pos_y[i];
234 
235 			input_report_abs(data->in_dev,
236 					 ABS_MT_POSITION_X, pos_x[i]);
237 			input_report_abs(data->in_dev,
238 					 ABS_MT_POSITION_Y, pos_y[i]);
239 			input_mt_sync(data->in_dev);
240 		}
241 	} else
242 		input_mt_sync(data->in_dev);
243 
244 	input_sync(data->in_dev);
245 
246 	return 0;
247 }
248 /**
249  * bu21013_gpio_irq() - gpio thread function for touch interrupt
250  * @irq: irq value
251  * @device_data: void pointer
252  *
253  * This gpio thread function for touch interrupt
254  * and returns irqreturn_t.
255  */
256 static irqreturn_t bu21013_gpio_irq(int irq, void *device_data)
257 {
258 	struct bu21013_ts_data *data = device_data;
259 	struct i2c_client *i2c = data->client;
260 	int retval;
261 
262 	do {
263 		retval = bu21013_do_touch_report(data);
264 		if (retval < 0) {
265 			dev_err(&i2c->dev, "bu21013_do_touch_report failed\n");
266 			return IRQ_NONE;
267 		}
268 
269 		data->intr_pin = gpio_get_value(data->chip->touch_pin);
270 		if (data->intr_pin == PEN_DOWN_INTR)
271 			wait_event_timeout(data->wait, data->touch_stopped,
272 					   msecs_to_jiffies(2));
273 	} while (!data->intr_pin && !data->touch_stopped);
274 
275 	return IRQ_HANDLED;
276 }
277 
278 /**
279  * bu21013_init_chip() - power on sequence for the bu21013 controller
280  * @data: device structure pointer
281  *
282  * This function is used to power on
283  * the bu21013 controller and returns integer.
284  */
285 static int bu21013_init_chip(struct bu21013_ts_data *data)
286 {
287 	int retval;
288 	struct i2c_client *i2c = data->client;
289 
290 	retval = i2c_smbus_write_byte_data(i2c, BU21013_RESET_REG,
291 					BU21013_RESET_ENABLE);
292 	if (retval < 0) {
293 		dev_err(&i2c->dev, "BU21013_RESET reg write failed\n");
294 		return retval;
295 	}
296 	msleep(RESET_DELAY);
297 
298 	retval = i2c_smbus_write_byte_data(i2c, BU21013_SENSOR_0_7_REG,
299 					BU21013_SENSORS_EN_0_7);
300 	if (retval < 0) {
301 		dev_err(&i2c->dev, "BU21013_SENSOR_0_7 reg write failed\n");
302 		return retval;
303 	}
304 
305 	retval = i2c_smbus_write_byte_data(i2c, BU21013_SENSOR_8_15_REG,
306 						BU21013_SENSORS_EN_8_15);
307 	if (retval < 0) {
308 		dev_err(&i2c->dev, "BU21013_SENSOR_8_15 reg write failed\n");
309 		return retval;
310 	}
311 
312 	retval = i2c_smbus_write_byte_data(i2c, BU21013_SENSOR_16_23_REG,
313 						BU21013_SENSORS_EN_16_23);
314 	if (retval < 0) {
315 		dev_err(&i2c->dev, "BU21013_SENSOR_16_23 reg write failed\n");
316 		return retval;
317 	}
318 
319 	retval = i2c_smbus_write_byte_data(i2c, BU21013_POS_MODE1_REG,
320 				(BU21013_POS_MODE1_0 | BU21013_POS_MODE1_1));
321 	if (retval < 0) {
322 		dev_err(&i2c->dev, "BU21013_POS_MODE1 reg write failed\n");
323 		return retval;
324 	}
325 
326 	retval = i2c_smbus_write_byte_data(i2c, BU21013_POS_MODE2_REG,
327 			(BU21013_POS_MODE2_ZERO | BU21013_POS_MODE2_AVG1 |
328 			BU21013_POS_MODE2_AVG2 | BU21013_POS_MODE2_EN_RAW |
329 			BU21013_POS_MODE2_MULTI));
330 	if (retval < 0) {
331 		dev_err(&i2c->dev, "BU21013_POS_MODE2 reg write failed\n");
332 		return retval;
333 	}
334 
335 	if (data->chip->ext_clk)
336 		retval = i2c_smbus_write_byte_data(i2c, BU21013_CLK_MODE_REG,
337 			(BU21013_CLK_MODE_EXT | BU21013_CLK_MODE_CALIB));
338 	else
339 		retval = i2c_smbus_write_byte_data(i2c, BU21013_CLK_MODE_REG,
340 			(BU21013_CLK_MODE_DIV | BU21013_CLK_MODE_CALIB));
341 	if (retval < 0) {
342 		dev_err(&i2c->dev, "BU21013_CLK_MODE reg write failed\n");
343 		return retval;
344 	}
345 
346 	retval = i2c_smbus_write_byte_data(i2c, BU21013_IDLE_REG,
347 				(BU21013_IDLET_0 | BU21013_IDLE_INTERMIT_EN));
348 	if (retval < 0) {
349 		dev_err(&i2c->dev, "BU21013_IDLE reg write failed\n");
350 		return retval;
351 	}
352 
353 	retval = i2c_smbus_write_byte_data(i2c, BU21013_INT_MODE_REG,
354 						BU21013_INT_MODE_LEVEL);
355 	if (retval < 0) {
356 		dev_err(&i2c->dev, "BU21013_INT_MODE reg write failed\n");
357 		return retval;
358 	}
359 
360 	retval = i2c_smbus_write_byte_data(i2c, BU21013_FILTER_REG,
361 						(BU21013_DELTA_0_6 |
362 							BU21013_FILTER_EN));
363 	if (retval < 0) {
364 		dev_err(&i2c->dev, "BU21013_FILTER reg write failed\n");
365 		return retval;
366 	}
367 
368 	retval = i2c_smbus_write_byte_data(i2c, BU21013_TH_ON_REG,
369 					BU21013_TH_ON_5);
370 	if (retval < 0) {
371 		dev_err(&i2c->dev, "BU21013_TH_ON reg write failed\n");
372 		return retval;
373 	}
374 
375 	retval = i2c_smbus_write_byte_data(i2c, BU21013_TH_OFF_REG,
376 				BU21013_TH_OFF_4 | BU21013_TH_OFF_3);
377 	if (retval < 0) {
378 		dev_err(&i2c->dev, "BU21013_TH_OFF reg write failed\n");
379 		return retval;
380 	}
381 
382 	retval = i2c_smbus_write_byte_data(i2c, BU21013_GAIN_REG,
383 					(BU21013_GAIN_0 | BU21013_GAIN_1));
384 	if (retval < 0) {
385 		dev_err(&i2c->dev, "BU21013_GAIN reg write failed\n");
386 		return retval;
387 	}
388 
389 	retval = i2c_smbus_write_byte_data(i2c, BU21013_OFFSET_MODE_REG,
390 					BU21013_OFFSET_MODE_DEFAULT);
391 	if (retval < 0) {
392 		dev_err(&i2c->dev, "BU21013_OFFSET_MODE reg write failed\n");
393 		return retval;
394 	}
395 
396 	retval = i2c_smbus_write_byte_data(i2c, BU21013_XY_EDGE_REG,
397 				(BU21013_X_EDGE_0 | BU21013_X_EDGE_2 |
398 				BU21013_Y_EDGE_1 | BU21013_Y_EDGE_3));
399 	if (retval < 0) {
400 		dev_err(&i2c->dev, "BU21013_XY_EDGE reg write failed\n");
401 		return retval;
402 	}
403 
404 	retval = i2c_smbus_write_byte_data(i2c, BU21013_DONE_REG,
405 							BU21013_DONE);
406 	if (retval < 0) {
407 		dev_err(&i2c->dev, "BU21013_REG_DONE reg write failed\n");
408 		return retval;
409 	}
410 
411 	return 0;
412 }
413 
414 /**
415  * bu21013_free_irq() - frees IRQ registered for touchscreen
416  * @bu21013_data: device structure pointer
417  *
418  * This function signals interrupt thread to stop processing and
419  * frees interrupt.
420  */
421 static void bu21013_free_irq(struct bu21013_ts_data *bu21013_data)
422 {
423 	bu21013_data->touch_stopped = true;
424 	wake_up(&bu21013_data->wait);
425 	free_irq(bu21013_data->irq, bu21013_data);
426 }
427 
428 /**
429  * bu21013_cs_disable() - deconfigures the touch panel controller
430  * @bu21013_data: device structure pointer
431  *
432  * This function is used to deconfigure the chip selection
433  * for touch panel controller.
434  */
435 static void bu21013_cs_disable(struct bu21013_ts_data *bu21013_data)
436 {
437 	int error;
438 
439 	error = gpio_direction_output(bu21013_data->chip->cs_pin, 0);
440 	if (error < 0)
441 		dev_warn(&bu21013_data->client->dev,
442 			 "%s: gpio direction failed, error: %d\n",
443 			 __func__, error);
444 	else
445 		gpio_set_value(bu21013_data->chip->cs_pin, 0);
446 
447 	gpio_free(bu21013_data->chip->cs_pin);
448 }
449 
450 #ifdef CONFIG_OF
451 static const struct bu21013_platform_device *
452 bu21013_parse_dt(struct device *dev)
453 {
454 	struct device_node *np = dev->of_node;
455 	struct bu21013_platform_device *pdata;
456 
457 	if (!np) {
458 		dev_err(dev, "no device tree or platform data\n");
459 		return ERR_PTR(-EINVAL);
460 	}
461 
462 	pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
463 	if (!pdata)
464 		return ERR_PTR(-ENOMEM);
465 
466 	pdata->y_flip = pdata->x_flip = false;
467 
468 	pdata->x_flip = of_property_read_bool(np, "rohm,flip-x");
469 	pdata->y_flip = of_property_read_bool(np, "rohm,flip-y");
470 
471 	of_property_read_u32(np, "rohm,touch-max-x", &pdata->touch_x_max);
472 	of_property_read_u32(np, "rohm,touch-max-y", &pdata->touch_y_max);
473 
474 	pdata->touch_pin = of_get_named_gpio(np, "touch-gpio", 0);
475 	pdata->cs_pin = of_get_named_gpio(np, "reset-gpio", 0);
476 
477 	pdata->ext_clk = false;
478 
479 	return pdata;
480 }
481 #else
482 static inline const struct bu21013_platform_device *
483 bu21013_parse_dt(struct device *dev)
484 {
485 	dev_err(dev, "no platform data available\n");
486 	return ERR_PTR(-EINVAL);
487 }
488 #endif
489 
490 /**
491  * bu21013_probe() - initializes the i2c-client touchscreen driver
492  * @client: i2c client structure pointer
493  * @id: i2c device id pointer
494  *
495  * This function used to initializes the i2c-client touchscreen
496  * driver and returns integer.
497  */
498 static int bu21013_probe(struct i2c_client *client,
499 			 const struct i2c_device_id *id)
500 {
501 	const struct bu21013_platform_device *pdata =
502 					dev_get_platdata(&client->dev);
503 	struct bu21013_ts_data *bu21013_data;
504 	struct input_dev *in_dev;
505 	int error;
506 
507 	if (!i2c_check_functionality(client->adapter,
508 					I2C_FUNC_SMBUS_BYTE_DATA)) {
509 		dev_err(&client->dev, "i2c smbus byte data not supported\n");
510 		return -EIO;
511 	}
512 
513 	if (!pdata) {
514 		pdata = bu21013_parse_dt(&client->dev);
515 		if (IS_ERR(pdata))
516 			return PTR_ERR(pdata);
517 	}
518 
519 	if (!gpio_is_valid(pdata->touch_pin)) {
520 		dev_err(&client->dev, "invalid touch_pin supplied\n");
521 		return -EINVAL;
522 	}
523 
524 	bu21013_data = kzalloc(sizeof(struct bu21013_ts_data), GFP_KERNEL);
525 	in_dev = input_allocate_device();
526 	if (!bu21013_data || !in_dev) {
527 		dev_err(&client->dev, "device memory alloc failed\n");
528 		error = -ENOMEM;
529 		goto err_free_mem;
530 	}
531 
532 	bu21013_data->in_dev = in_dev;
533 	bu21013_data->chip = pdata;
534 	bu21013_data->client = client;
535 	bu21013_data->irq = gpio_to_irq(pdata->touch_pin);
536 
537 	bu21013_data->regulator = regulator_get(&client->dev, "avdd");
538 	if (IS_ERR(bu21013_data->regulator)) {
539 		dev_err(&client->dev, "regulator_get failed\n");
540 		error = PTR_ERR(bu21013_data->regulator);
541 		goto err_free_mem;
542 	}
543 
544 	error = regulator_enable(bu21013_data->regulator);
545 	if (error < 0) {
546 		dev_err(&client->dev, "regulator enable failed\n");
547 		goto err_put_regulator;
548 	}
549 
550 	bu21013_data->touch_stopped = false;
551 	init_waitqueue_head(&bu21013_data->wait);
552 
553 	/* configure the gpio pins */
554 	error = gpio_request_one(pdata->cs_pin, GPIOF_OUT_INIT_HIGH,
555 				 "touchp_reset");
556 	if (error < 0) {
557 		dev_err(&client->dev, "Unable to request gpio reset_pin\n");
558 		goto err_disable_regulator;
559 	}
560 
561 	/* configure the touch panel controller */
562 	error = bu21013_init_chip(bu21013_data);
563 	if (error) {
564 		dev_err(&client->dev, "error in bu21013 config\n");
565 		goto err_cs_disable;
566 	}
567 
568 	/* register the device to input subsystem */
569 	in_dev->name = DRIVER_TP;
570 	in_dev->id.bustype = BUS_I2C;
571 	in_dev->dev.parent = &client->dev;
572 
573 	__set_bit(EV_SYN, in_dev->evbit);
574 	__set_bit(EV_KEY, in_dev->evbit);
575 	__set_bit(EV_ABS, in_dev->evbit);
576 
577 	input_set_abs_params(in_dev, ABS_MT_POSITION_X, 0,
578 						pdata->touch_x_max, 0, 0);
579 	input_set_abs_params(in_dev, ABS_MT_POSITION_Y, 0,
580 						pdata->touch_y_max, 0, 0);
581 	input_set_drvdata(in_dev, bu21013_data);
582 
583 	error = request_threaded_irq(bu21013_data->irq, NULL, bu21013_gpio_irq,
584 				     IRQF_TRIGGER_FALLING | IRQF_SHARED |
585 					IRQF_ONESHOT,
586 				     DRIVER_TP, bu21013_data);
587 	if (error) {
588 		dev_err(&client->dev, "request irq %d failed\n",
589 			bu21013_data->irq);
590 		goto err_cs_disable;
591 	}
592 
593 	error = input_register_device(in_dev);
594 	if (error) {
595 		dev_err(&client->dev, "failed to register input device\n");
596 		goto err_free_irq;
597 	}
598 
599 	device_init_wakeup(&client->dev, pdata->wakeup);
600 	i2c_set_clientdata(client, bu21013_data);
601 
602 	return 0;
603 
604 err_free_irq:
605 	bu21013_free_irq(bu21013_data);
606 err_cs_disable:
607 	bu21013_cs_disable(bu21013_data);
608 err_disable_regulator:
609 	regulator_disable(bu21013_data->regulator);
610 err_put_regulator:
611 	regulator_put(bu21013_data->regulator);
612 err_free_mem:
613 	input_free_device(in_dev);
614 	kfree(bu21013_data);
615 
616 	return error;
617 }
618 /**
619  * bu21013_remove() - removes the i2c-client touchscreen driver
620  * @client: i2c client structure pointer
621  *
622  * This function uses to remove the i2c-client
623  * touchscreen driver and returns integer.
624  */
625 static int bu21013_remove(struct i2c_client *client)
626 {
627 	struct bu21013_ts_data *bu21013_data = i2c_get_clientdata(client);
628 
629 	bu21013_free_irq(bu21013_data);
630 
631 	bu21013_cs_disable(bu21013_data);
632 
633 	input_unregister_device(bu21013_data->in_dev);
634 
635 	regulator_disable(bu21013_data->regulator);
636 	regulator_put(bu21013_data->regulator);
637 
638 	kfree(bu21013_data);
639 
640 	device_init_wakeup(&client->dev, false);
641 
642 	return 0;
643 }
644 
645 #ifdef CONFIG_PM
646 /**
647  * bu21013_suspend() - suspend the touch screen controller
648  * @dev: pointer to device structure
649  *
650  * This function is used to suspend the
651  * touch panel controller and returns integer
652  */
653 static int bu21013_suspend(struct device *dev)
654 {
655 	struct bu21013_ts_data *bu21013_data = dev_get_drvdata(dev);
656 	struct i2c_client *client = bu21013_data->client;
657 
658 	bu21013_data->touch_stopped = true;
659 	if (device_may_wakeup(&client->dev))
660 		enable_irq_wake(bu21013_data->irq);
661 	else
662 		disable_irq(bu21013_data->irq);
663 
664 	regulator_disable(bu21013_data->regulator);
665 
666 	return 0;
667 }
668 
669 /**
670  * bu21013_resume() - resume the touch screen controller
671  * @dev: pointer to device structure
672  *
673  * This function is used to resume the touch panel
674  * controller and returns integer.
675  */
676 static int bu21013_resume(struct device *dev)
677 {
678 	struct bu21013_ts_data *bu21013_data = dev_get_drvdata(dev);
679 	struct i2c_client *client = bu21013_data->client;
680 	int retval;
681 
682 	retval = regulator_enable(bu21013_data->regulator);
683 	if (retval < 0) {
684 		dev_err(&client->dev, "bu21013 regulator enable failed\n");
685 		return retval;
686 	}
687 
688 	retval = bu21013_init_chip(bu21013_data);
689 	if (retval < 0) {
690 		dev_err(&client->dev, "bu21013 controller config failed\n");
691 		return retval;
692 	}
693 
694 	bu21013_data->touch_stopped = false;
695 
696 	if (device_may_wakeup(&client->dev))
697 		disable_irq_wake(bu21013_data->irq);
698 	else
699 		enable_irq(bu21013_data->irq);
700 
701 	return 0;
702 }
703 
704 static const struct dev_pm_ops bu21013_dev_pm_ops = {
705 	.suspend = bu21013_suspend,
706 	.resume  = bu21013_resume,
707 };
708 #endif
709 
710 static const struct i2c_device_id bu21013_id[] = {
711 	{ DRIVER_TP, 0 },
712 	{ }
713 };
714 MODULE_DEVICE_TABLE(i2c, bu21013_id);
715 
716 static struct i2c_driver bu21013_driver = {
717 	.driver	= {
718 		.name	=	DRIVER_TP,
719 #ifdef CONFIG_PM
720 		.pm	=	&bu21013_dev_pm_ops,
721 #endif
722 	},
723 	.probe		=	bu21013_probe,
724 	.remove		=	bu21013_remove,
725 	.id_table	=	bu21013_id,
726 };
727 
728 module_i2c_driver(bu21013_driver);
729 
730 MODULE_LICENSE("GPL v2");
731 MODULE_AUTHOR("Naveen Kumar G <naveen.gaddipati@stericsson.com>");
732 MODULE_DESCRIPTION("bu21013 touch screen controller driver");
733