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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 */
147struct 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 */
165static 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 */
186static 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 */
251static 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 */
280static 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 */
416static 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 */
431static 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
529err_free_irq:
530 bu21013_free_irq(bu21013_data);
531err_cs_disable:
532 pdata->cs_dis(pdata->cs_pin);
533err_disable_regulator:
534 regulator_disable(bu21013_data->regulator);
535err_put_regulator:
536 regulator_put(bu21013_data->regulator);
537err_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 */
550static 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 */
578static 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 */
601static 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
629static const struct dev_pm_ops bu21013_dev_pm_ops = {
630 .suspend = bu21013_suspend,
631 .resume = bu21013_resume,
632};
633#endif
634
635static const struct i2c_device_id bu21013_id[] = {
636 { DRIVER_TP, 0 },
637 { }
638};
639MODULE_DEVICE_TABLE(i2c, bu21013_id);
640
641static 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 */
660static 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 */
671static void __exit bu21013_exit(void)
672{
673 i2c_del_driver(&bu21013_driver);
674}
675
676module_init(bu21013_init);
677module_exit(bu21013_exit);
678
679MODULE_LICENSE("GPL v2");
680MODULE_AUTHOR("Naveen Kumar G <naveen.gaddipati@stericsson.com>");
681MODULE_DESCRIPTION("bu21013 touch screen controller driver");
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (C) ST-Ericsson SA 2010
4 * Author: Naveen Kumar G <naveen.gaddipati@stericsson.com> for ST-Ericsson
5 */
6
7#include <linux/bitops.h>
8#include <linux/delay.h>
9#include <linux/gpio/consumer.h>
10#include <linux/i2c.h>
11#include <linux/input.h>
12#include <linux/input/mt.h>
13#include <linux/input/touchscreen.h>
14#include <linux/interrupt.h>
15#include <linux/kernel.h>
16#include <linux/module.h>
17#include <linux/property.h>
18#include <linux/regulator/consumer.h>
19#include <linux/slab.h>
20#include <linux/types.h>
21
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 - touch panel data structure
141 * @client: pointer to the i2c client
142 * @in_dev: pointer to the input device structure
143 * @props: the device coordinate transformation properties
144 * @regulator: pointer to the Regulator used for touch screen
145 * @cs_gpiod: chip select GPIO line
146 * @int_gpiod: touch interrupt GPIO line
147 * @touch_x_max: maximum X coordinate reported by the device
148 * @touch_y_max: maximum Y coordinate reported by the device
149 * @x_flip: indicates that the driver should invert X coordinate before
150 * reporting
151 * @y_flip: indicates that the driver should invert Y coordinate before
152 * reporting
153 * @touch_stopped: touch stop flag
154 *
155 * Touch panel device data structure
156 */
157struct bu21013_ts {
158 struct i2c_client *client;
159 struct input_dev *in_dev;
160 struct touchscreen_properties props;
161 struct regulator *regulator;
162 struct gpio_desc *cs_gpiod;
163 struct gpio_desc *int_gpiod;
164 u32 touch_x_max;
165 u32 touch_y_max;
166 bool x_flip;
167 bool y_flip;
168 bool touch_stopped;
169};
170
171static int bu21013_read_block_data(struct bu21013_ts *ts, u8 *buf)
172{
173 int ret, i;
174
175 for (i = 0; i < I2C_RETRY_COUNT; i++) {
176 ret = i2c_smbus_read_i2c_block_data(ts->client,
177 BU21013_SENSORS_BTN_0_7_REG,
178 LENGTH_OF_BUFFER, buf);
179 if (ret == LENGTH_OF_BUFFER)
180 return 0;
181 }
182
183 return -EINVAL;
184}
185
186static int bu21013_do_touch_report(struct bu21013_ts *ts)
187{
188 struct input_dev *input = ts->in_dev;
189 struct input_mt_pos pos[MAX_FINGERS];
190 int slots[MAX_FINGERS];
191 u8 buf[LENGTH_OF_BUFFER];
192 bool has_x_sensors, has_y_sensors;
193 int finger_down_count = 0;
194 int i;
195
196 if (bu21013_read_block_data(ts, buf) < 0)
197 return -EINVAL;
198
199 has_x_sensors = hweight32(buf[0] & BU21013_SENSORS_EN_0_7);
200 has_y_sensors = hweight32(((buf[1] & BU21013_SENSORS_EN_8_15) |
201 ((buf[2] & BU21013_SENSORS_EN_16_23) << SHIFT_8)) >> SHIFT_2);
202 if (!has_x_sensors || !has_y_sensors)
203 return 0;
204
205 for (i = 0; i < MAX_FINGERS; i++) {
206 const u8 *data = &buf[4 * i + 3];
207 unsigned int x, y;
208
209 x = data[0] << SHIFT_2 | (data[1] & MASK_BITS);
210 y = data[2] << SHIFT_2 | (data[3] & MASK_BITS);
211 if (x != 0 && y != 0)
212 touchscreen_set_mt_pos(&pos[finger_down_count++],
213 &ts->props, x, y);
214 }
215
216 if (finger_down_count == 2 &&
217 (abs(pos[0].x - pos[1].x) < DELTA_MIN ||
218 abs(pos[0].y - pos[1].y) < DELTA_MIN)) {
219 return 0;
220 }
221
222 input_mt_assign_slots(input, slots, pos, finger_down_count, DELTA_MIN);
223 for (i = 0; i < finger_down_count; i++) {
224 input_mt_slot(input, slots[i]);
225 input_mt_report_slot_state(input, MT_TOOL_FINGER, true);
226 input_report_abs(input, ABS_MT_POSITION_X, pos[i].x);
227 input_report_abs(input, ABS_MT_POSITION_Y, pos[i].y);
228 }
229
230 input_mt_sync_frame(input);
231 input_sync(input);
232
233 return 0;
234}
235
236static irqreturn_t bu21013_gpio_irq(int irq, void *device_data)
237{
238 struct bu21013_ts *ts = device_data;
239 int keep_polling;
240 int error;
241
242 do {
243 error = bu21013_do_touch_report(ts);
244 if (error) {
245 dev_err(&ts->client->dev, "%s failed\n", __func__);
246 break;
247 }
248
249 if (unlikely(ts->touch_stopped))
250 break;
251
252 keep_polling = ts->int_gpiod ?
253 gpiod_get_value(ts->int_gpiod) : false;
254 if (keep_polling)
255 usleep_range(2000, 2500);
256 } while (keep_polling);
257
258 return IRQ_HANDLED;
259}
260
261static int bu21013_init_chip(struct bu21013_ts *ts)
262{
263 struct i2c_client *client = ts->client;
264 int error;
265
266 error = i2c_smbus_write_byte_data(client, BU21013_RESET_REG,
267 BU21013_RESET_ENABLE);
268 if (error) {
269 dev_err(&client->dev, "BU21013_RESET reg write failed\n");
270 return error;
271 }
272 msleep(RESET_DELAY);
273
274 error = i2c_smbus_write_byte_data(client, BU21013_SENSOR_0_7_REG,
275 BU21013_SENSORS_EN_0_7);
276 if (error) {
277 dev_err(&client->dev, "BU21013_SENSOR_0_7 reg write failed\n");
278 return error;
279 }
280
281 error = i2c_smbus_write_byte_data(client, BU21013_SENSOR_8_15_REG,
282 BU21013_SENSORS_EN_8_15);
283 if (error) {
284 dev_err(&client->dev, "BU21013_SENSOR_8_15 reg write failed\n");
285 return error;
286 }
287
288 error = i2c_smbus_write_byte_data(client, BU21013_SENSOR_16_23_REG,
289 BU21013_SENSORS_EN_16_23);
290 if (error) {
291 dev_err(&client->dev, "BU21013_SENSOR_16_23 reg write failed\n");
292 return error;
293 }
294
295 error = i2c_smbus_write_byte_data(client, BU21013_POS_MODE1_REG,
296 BU21013_POS_MODE1_0 |
297 BU21013_POS_MODE1_1);
298 if (error) {
299 dev_err(&client->dev, "BU21013_POS_MODE1 reg write failed\n");
300 return error;
301 }
302
303 error = i2c_smbus_write_byte_data(client, BU21013_POS_MODE2_REG,
304 BU21013_POS_MODE2_ZERO |
305 BU21013_POS_MODE2_AVG1 |
306 BU21013_POS_MODE2_AVG2 |
307 BU21013_POS_MODE2_EN_RAW |
308 BU21013_POS_MODE2_MULTI);
309 if (error) {
310 dev_err(&client->dev, "BU21013_POS_MODE2 reg write failed\n");
311 return error;
312 }
313
314 error = i2c_smbus_write_byte_data(client, BU21013_CLK_MODE_REG,
315 BU21013_CLK_MODE_DIV |
316 BU21013_CLK_MODE_CALIB);
317 if (error) {
318 dev_err(&client->dev, "BU21013_CLK_MODE reg write failed\n");
319 return error;
320 }
321
322 error = i2c_smbus_write_byte_data(client, BU21013_IDLE_REG,
323 BU21013_IDLET_0 |
324 BU21013_IDLE_INTERMIT_EN);
325 if (error) {
326 dev_err(&client->dev, "BU21013_IDLE reg write failed\n");
327 return error;
328 }
329
330 error = i2c_smbus_write_byte_data(client, BU21013_INT_MODE_REG,
331 BU21013_INT_MODE_LEVEL);
332 if (error) {
333 dev_err(&client->dev, "BU21013_INT_MODE reg write failed\n");
334 return error;
335 }
336
337 error = i2c_smbus_write_byte_data(client, BU21013_FILTER_REG,
338 BU21013_DELTA_0_6 |
339 BU21013_FILTER_EN);
340 if (error) {
341 dev_err(&client->dev, "BU21013_FILTER reg write failed\n");
342 return error;
343 }
344
345 error = i2c_smbus_write_byte_data(client, BU21013_TH_ON_REG,
346 BU21013_TH_ON_5);
347 if (error) {
348 dev_err(&client->dev, "BU21013_TH_ON reg write failed\n");
349 return error;
350 }
351
352 error = i2c_smbus_write_byte_data(client, BU21013_TH_OFF_REG,
353 BU21013_TH_OFF_4 | BU21013_TH_OFF_3);
354 if (error) {
355 dev_err(&client->dev, "BU21013_TH_OFF reg write failed\n");
356 return error;
357 }
358
359 error = i2c_smbus_write_byte_data(client, BU21013_GAIN_REG,
360 BU21013_GAIN_0 | BU21013_GAIN_1);
361 if (error) {
362 dev_err(&client->dev, "BU21013_GAIN reg write failed\n");
363 return error;
364 }
365
366 error = i2c_smbus_write_byte_data(client, BU21013_OFFSET_MODE_REG,
367 BU21013_OFFSET_MODE_DEFAULT);
368 if (error) {
369 dev_err(&client->dev, "BU21013_OFFSET_MODE reg write failed\n");
370 return error;
371 }
372
373 error = i2c_smbus_write_byte_data(client, BU21013_XY_EDGE_REG,
374 BU21013_X_EDGE_0 |
375 BU21013_X_EDGE_2 |
376 BU21013_Y_EDGE_1 |
377 BU21013_Y_EDGE_3);
378 if (error) {
379 dev_err(&client->dev, "BU21013_XY_EDGE reg write failed\n");
380 return error;
381 }
382
383 error = i2c_smbus_write_byte_data(client, BU21013_DONE_REG,
384 BU21013_DONE);
385 if (error) {
386 dev_err(&client->dev, "BU21013_REG_DONE reg write failed\n");
387 return error;
388 }
389
390 return 0;
391}
392
393static void bu21013_power_off(void *_ts)
394{
395 struct bu21013_ts *ts = _ts;
396
397 regulator_disable(ts->regulator);
398}
399
400static void bu21013_disable_chip(void *_ts)
401{
402 struct bu21013_ts *ts = _ts;
403
404 gpiod_set_value(ts->cs_gpiod, 0);
405}
406
407static int bu21013_probe(struct i2c_client *client,
408 const struct i2c_device_id *id)
409{
410 struct bu21013_ts *ts;
411 struct input_dev *in_dev;
412 struct input_absinfo *info;
413 u32 max_x = 0, max_y = 0;
414 int error;
415
416 if (!i2c_check_functionality(client->adapter,
417 I2C_FUNC_SMBUS_BYTE_DATA)) {
418 dev_err(&client->dev, "i2c smbus byte data not supported\n");
419 return -EIO;
420 }
421
422 if (!client->irq) {
423 dev_err(&client->dev, "No IRQ set up\n");
424 return -EINVAL;
425 }
426
427 ts = devm_kzalloc(&client->dev, sizeof(*ts), GFP_KERNEL);
428 if (!ts)
429 return -ENOMEM;
430
431 ts->client = client;
432
433 ts->x_flip = device_property_read_bool(&client->dev, "rohm,flip-x");
434 ts->y_flip = device_property_read_bool(&client->dev, "rohm,flip-y");
435
436 in_dev = devm_input_allocate_device(&client->dev);
437 if (!in_dev) {
438 dev_err(&client->dev, "device memory alloc failed\n");
439 return -ENOMEM;
440 }
441 ts->in_dev = in_dev;
442 input_set_drvdata(in_dev, ts);
443
444 /* register the device to input subsystem */
445 in_dev->name = DRIVER_TP;
446 in_dev->id.bustype = BUS_I2C;
447
448 device_property_read_u32(&client->dev, "rohm,touch-max-x", &max_x);
449 device_property_read_u32(&client->dev, "rohm,touch-max-y", &max_y);
450
451 input_set_abs_params(in_dev, ABS_MT_POSITION_X, 0, max_x, 0, 0);
452 input_set_abs_params(in_dev, ABS_MT_POSITION_Y, 0, max_y, 0, 0);
453
454 touchscreen_parse_properties(in_dev, true, &ts->props);
455
456 /* Adjust for the legacy "flip" properties, if present */
457 if (!ts->props.invert_x &&
458 device_property_read_bool(&client->dev, "rohm,flip-x")) {
459 info = &in_dev->absinfo[ABS_MT_POSITION_X];
460 info->maximum -= info->minimum;
461 info->minimum = 0;
462 }
463
464 if (!ts->props.invert_y &&
465 device_property_read_bool(&client->dev, "rohm,flip-y")) {
466 info = &in_dev->absinfo[ABS_MT_POSITION_Y];
467 info->maximum -= info->minimum;
468 info->minimum = 0;
469 }
470
471 error = input_mt_init_slots(in_dev, MAX_FINGERS,
472 INPUT_MT_DIRECT | INPUT_MT_TRACK |
473 INPUT_MT_DROP_UNUSED);
474 if (error) {
475 dev_err(&client->dev, "failed to initialize MT slots");
476 return error;
477 }
478
479 ts->regulator = devm_regulator_get(&client->dev, "avdd");
480 if (IS_ERR(ts->regulator)) {
481 dev_err(&client->dev, "regulator_get failed\n");
482 return PTR_ERR(ts->regulator);
483 }
484
485 error = regulator_enable(ts->regulator);
486 if (error) {
487 dev_err(&client->dev, "regulator enable failed\n");
488 return error;
489 }
490
491 error = devm_add_action_or_reset(&client->dev, bu21013_power_off, ts);
492 if (error) {
493 dev_err(&client->dev, "failed to install power off handler\n");
494 return error;
495 }
496
497 /* Named "CS" on the chip, DT binding is "reset" */
498 ts->cs_gpiod = devm_gpiod_get(&client->dev, "reset", GPIOD_OUT_HIGH);
499 error = PTR_ERR_OR_ZERO(ts->cs_gpiod);
500 if (error) {
501 if (error != -EPROBE_DEFER)
502 dev_err(&client->dev, "failed to get CS GPIO\n");
503 return error;
504 }
505 gpiod_set_consumer_name(ts->cs_gpiod, "BU21013 CS");
506
507 error = devm_add_action_or_reset(&client->dev,
508 bu21013_disable_chip, ts);
509 if (error) {
510 dev_err(&client->dev,
511 "failed to install chip disable handler\n");
512 return error;
513 }
514
515 /* Named "INT" on the chip, DT binding is "touch" */
516 ts->int_gpiod = devm_gpiod_get_optional(&client->dev,
517 "touch", GPIOD_IN);
518 error = PTR_ERR_OR_ZERO(ts->int_gpiod);
519 if (error) {
520 if (error != -EPROBE_DEFER)
521 dev_err(&client->dev, "failed to get INT GPIO\n");
522 return error;
523 }
524
525 if (ts->int_gpiod)
526 gpiod_set_consumer_name(ts->int_gpiod, "BU21013 INT");
527
528 /* configure the touch panel controller */
529 error = bu21013_init_chip(ts);
530 if (error) {
531 dev_err(&client->dev, "error in bu21013 config\n");
532 return error;
533 }
534
535 error = devm_request_threaded_irq(&client->dev, client->irq,
536 NULL, bu21013_gpio_irq,
537 IRQF_ONESHOT, DRIVER_TP, ts);
538 if (error) {
539 dev_err(&client->dev, "request irq %d failed\n",
540 client->irq);
541 return error;
542 }
543
544 error = input_register_device(in_dev);
545 if (error) {
546 dev_err(&client->dev, "failed to register input device\n");
547 return error;
548 }
549
550 i2c_set_clientdata(client, ts);
551
552 return 0;
553}
554
555static int bu21013_remove(struct i2c_client *client)
556{
557 struct bu21013_ts *ts = i2c_get_clientdata(client);
558
559 /* Make sure IRQ will exit quickly even if there is contact */
560 ts->touch_stopped = true;
561 /* The resources will be freed by devm */
562
563 return 0;
564}
565
566static int __maybe_unused bu21013_suspend(struct device *dev)
567{
568 struct i2c_client *client = to_i2c_client(dev);
569 struct bu21013_ts *ts = i2c_get_clientdata(client);
570
571 ts->touch_stopped = true;
572 mb();
573 disable_irq(client->irq);
574
575 if (!device_may_wakeup(&client->dev))
576 regulator_disable(ts->regulator);
577
578 return 0;
579}
580
581static int __maybe_unused bu21013_resume(struct device *dev)
582{
583 struct i2c_client *client = to_i2c_client(dev);
584 struct bu21013_ts *ts = i2c_get_clientdata(client);
585 int error;
586
587 if (!device_may_wakeup(&client->dev)) {
588 error = regulator_enable(ts->regulator);
589 if (error) {
590 dev_err(&client->dev,
591 "failed to re-enable regulator when resuming\n");
592 return error;
593 }
594
595 error = bu21013_init_chip(ts);
596 if (error) {
597 dev_err(&client->dev,
598 "failed to reinitialize chip when resuming\n");
599 return error;
600 }
601 }
602
603 ts->touch_stopped = false;
604 mb();
605 enable_irq(client->irq);
606
607 return 0;
608}
609
610static SIMPLE_DEV_PM_OPS(bu21013_dev_pm_ops, bu21013_suspend, bu21013_resume);
611
612static const struct i2c_device_id bu21013_id[] = {
613 { DRIVER_TP, 0 },
614 { }
615};
616MODULE_DEVICE_TABLE(i2c, bu21013_id);
617
618static struct i2c_driver bu21013_driver = {
619 .driver = {
620 .name = DRIVER_TP,
621 .pm = &bu21013_dev_pm_ops,
622 },
623 .probe = bu21013_probe,
624 .remove = bu21013_remove,
625 .id_table = bu21013_id,
626};
627
628module_i2c_driver(bu21013_driver);
629
630MODULE_LICENSE("GPL v2");
631MODULE_AUTHOR("Naveen Kumar G <naveen.gaddipati@stericsson.com>");
632MODULE_DESCRIPTION("bu21013 touch screen controller driver");