xref: /linux/drivers/input/mouse/synaptics_i2c.c (revision 27258e448eb301cf89e351df87aa8cb916653bf2)
1 /*
2  * Synaptics touchpad with I2C interface
3  *
4  * Copyright (C) 2009 Compulab, Ltd.
5  * Mike Rapoport <mike@compulab.co.il>
6  * Igor Grinberg <grinberg@compulab.co.il>
7  *
8  * This file is subject to the terms and conditions of the GNU General Public
9  * License.  See the file COPYING in the main directory of this archive for
10  * more details.
11  */
12 
13 #include <linux/module.h>
14 #include <linux/i2c.h>
15 #include <linux/irq.h>
16 #include <linux/interrupt.h>
17 #include <linux/input.h>
18 #include <linux/delay.h>
19 #include <linux/workqueue.h>
20 
21 #define DRIVER_NAME		"synaptics_i2c"
22 /* maximum product id is 15 characters */
23 #define PRODUCT_ID_LENGTH	15
24 #define REGISTER_LENGTH		8
25 
26 /*
27  * after soft reset, we should wait for 1 ms
28  * before the device becomes operational
29  */
30 #define SOFT_RESET_DELAY_MS	3
31 /* and after hard reset, we should wait for max 500ms */
32 #define HARD_RESET_DELAY_MS	500
33 
34 /* Registers by SMBus address */
35 #define PAGE_SEL_REG		0xff
36 #define DEVICE_STATUS_REG	0x09
37 
38 /* Registers by RMI address */
39 #define DEV_CONTROL_REG		0x0000
40 #define INTERRUPT_EN_REG	0x0001
41 #define ERR_STAT_REG		0x0002
42 #define INT_REQ_STAT_REG	0x0003
43 #define DEV_COMMAND_REG		0x0004
44 
45 #define RMI_PROT_VER_REG	0x0200
46 #define MANUFACT_ID_REG		0x0201
47 #define PHYS_INT_VER_REG	0x0202
48 #define PROD_PROPERTY_REG	0x0203
49 #define INFO_QUERY_REG0		0x0204
50 #define INFO_QUERY_REG1		(INFO_QUERY_REG0 + 1)
51 #define INFO_QUERY_REG2		(INFO_QUERY_REG0 + 2)
52 #define INFO_QUERY_REG3		(INFO_QUERY_REG0 + 3)
53 
54 #define PRODUCT_ID_REG0		0x0210
55 #define PRODUCT_ID_REG1		(PRODUCT_ID_REG0 + 1)
56 #define PRODUCT_ID_REG2		(PRODUCT_ID_REG0 + 2)
57 #define PRODUCT_ID_REG3		(PRODUCT_ID_REG0 + 3)
58 #define PRODUCT_ID_REG4		(PRODUCT_ID_REG0 + 4)
59 #define PRODUCT_ID_REG5		(PRODUCT_ID_REG0 + 5)
60 #define PRODUCT_ID_REG6		(PRODUCT_ID_REG0 + 6)
61 #define PRODUCT_ID_REG7		(PRODUCT_ID_REG0 + 7)
62 #define PRODUCT_ID_REG8		(PRODUCT_ID_REG0 + 8)
63 #define PRODUCT_ID_REG9		(PRODUCT_ID_REG0 + 9)
64 #define PRODUCT_ID_REG10	(PRODUCT_ID_REG0 + 10)
65 #define PRODUCT_ID_REG11	(PRODUCT_ID_REG0 + 11)
66 #define PRODUCT_ID_REG12	(PRODUCT_ID_REG0 + 12)
67 #define PRODUCT_ID_REG13	(PRODUCT_ID_REG0 + 13)
68 #define PRODUCT_ID_REG14	(PRODUCT_ID_REG0 + 14)
69 #define PRODUCT_ID_REG15	(PRODUCT_ID_REG0 + 15)
70 
71 #define DATA_REG0		0x0400
72 #define ABS_PRESSURE_REG	0x0401
73 #define ABS_MSB_X_REG		0x0402
74 #define ABS_LSB_X_REG		(ABS_MSB_X_REG + 1)
75 #define ABS_MSB_Y_REG		0x0404
76 #define ABS_LSB_Y_REG		(ABS_MSB_Y_REG + 1)
77 #define REL_X_REG		0x0406
78 #define REL_Y_REG		0x0407
79 
80 #define DEV_QUERY_REG0		0x1000
81 #define DEV_QUERY_REG1		(DEV_QUERY_REG0 + 1)
82 #define DEV_QUERY_REG2		(DEV_QUERY_REG0 + 2)
83 #define DEV_QUERY_REG3		(DEV_QUERY_REG0 + 3)
84 #define DEV_QUERY_REG4		(DEV_QUERY_REG0 + 4)
85 #define DEV_QUERY_REG5		(DEV_QUERY_REG0 + 5)
86 #define DEV_QUERY_REG6		(DEV_QUERY_REG0 + 6)
87 #define DEV_QUERY_REG7		(DEV_QUERY_REG0 + 7)
88 #define DEV_QUERY_REG8		(DEV_QUERY_REG0 + 8)
89 
90 #define GENERAL_2D_CONTROL_REG	0x1041
91 #define SENSOR_SENSITIVITY_REG	0x1044
92 #define SENS_MAX_POS_MSB_REG	0x1046
93 #define SENS_MAX_POS_LSB_REG	(SENS_MAX_POS_UPPER_REG + 1)
94 
95 /* Register bits */
96 /* Device Control Register Bits */
97 #define REPORT_RATE_1ST_BIT	6
98 
99 /* Interrupt Enable Register Bits (INTERRUPT_EN_REG) */
100 #define F10_ABS_INT_ENA		0
101 #define F10_REL_INT_ENA		1
102 #define F20_INT_ENA		2
103 
104 /* Interrupt Request Register Bits (INT_REQ_STAT_REG | DEVICE_STATUS_REG) */
105 #define F10_ABS_INT_REQ		0
106 #define F10_REL_INT_REQ		1
107 #define F20_INT_REQ		2
108 /* Device Status Register Bits (DEVICE_STATUS_REG) */
109 #define STAT_CONFIGURED		6
110 #define STAT_ERROR		7
111 
112 /* Device Command Register Bits (DEV_COMMAND_REG) */
113 #define RESET_COMMAND		0x01
114 #define REZERO_COMMAND		0x02
115 
116 /* Data Register 0 Bits (DATA_REG0) */
117 #define GESTURE			3
118 
119 /* Device Query Registers Bits */
120 /* DEV_QUERY_REG3 */
121 #define HAS_PALM_DETECT		1
122 #define HAS_MULTI_FING		2
123 #define HAS_SCROLLER		4
124 #define HAS_2D_SCROLL		5
125 
126 /* General 2D Control Register Bits (GENERAL_2D_CONTROL_REG) */
127 #define NO_DECELERATION		1
128 #define REDUCE_REPORTING	3
129 #define NO_FILTER		5
130 
131 /* Function Masks */
132 /* Device Control Register Masks (DEV_CONTROL_REG) */
133 #define REPORT_RATE_MSK		0xc0
134 #define SLEEP_MODE_MSK		0x07
135 
136 /* Device Sleep Modes */
137 #define FULL_AWAKE		0x0
138 #define NORMAL_OP		0x1
139 #define LOW_PWR_OP		0x2
140 #define VERY_LOW_PWR_OP		0x3
141 #define SENS_SLEEP		0x4
142 #define SLEEP_MOD		0x5
143 #define DEEP_SLEEP		0x6
144 #define HIBERNATE		0x7
145 
146 /* Interrupt Register Mask */
147 /* (INT_REQ_STAT_REG | DEVICE_STATUS_REG | INTERRUPT_EN_REG) */
148 #define INT_ENA_REQ_MSK		0x07
149 #define INT_ENA_ABS_MSK		0x01
150 #define INT_ENA_REL_MSK		0x02
151 #define INT_ENA_F20_MSK		0x04
152 
153 /* Device Status Register Masks (DEVICE_STATUS_REG) */
154 #define CONFIGURED_MSK		0x40
155 #define ERROR_MSK		0x80
156 
157 /* Data Register 0 Masks */
158 #define FINGER_WIDTH_MSK	0xf0
159 #define GESTURE_MSK		0x08
160 #define SENSOR_STATUS_MSK	0x07
161 
162 /*
163  * MSB Position Register Masks
164  * ABS_MSB_X_REG | ABS_MSB_Y_REG | SENS_MAX_POS_MSB_REG |
165  * DEV_QUERY_REG3 | DEV_QUERY_REG5
166  */
167 #define MSB_POSITION_MSK	0x1f
168 
169 /* Device Query Registers Masks */
170 
171 /* DEV_QUERY_REG2 */
172 #define NUM_EXTRA_POS_MSK	0x07
173 
174 /* When in IRQ mode read the device every THREAD_IRQ_SLEEP_SECS */
175 #define THREAD_IRQ_SLEEP_SECS	2
176 #define THREAD_IRQ_SLEEP_MSECS	(THREAD_IRQ_SLEEP_SECS * MSEC_PER_SEC)
177 
178 /*
179  * When in Polling mode and no data received for NO_DATA_THRES msecs
180  * reduce the polling rate to NO_DATA_SLEEP_MSECS
181  */
182 #define NO_DATA_THRES		(MSEC_PER_SEC)
183 #define NO_DATA_SLEEP_MSECS	(MSEC_PER_SEC / 4)
184 
185 /* Control touchpad's No Deceleration option */
186 static int no_decel = 1;
187 module_param(no_decel, bool, 0644);
188 MODULE_PARM_DESC(no_decel, "No Deceleration. Default = 1 (on)");
189 
190 /* Control touchpad's Reduced Reporting option */
191 static int reduce_report;
192 module_param(reduce_report, bool, 0644);
193 MODULE_PARM_DESC(reduce_report, "Reduced Reporting. Default = 0 (off)");
194 
195 /* Control touchpad's No Filter option */
196 static int no_filter;
197 module_param(no_filter, bool, 0644);
198 MODULE_PARM_DESC(no_filter, "No Filter. Default = 0 (off)");
199 
200 /*
201  * touchpad Attention line is Active Low and Open Drain,
202  * therefore should be connected to pulled up line
203  * and the irq configuration should be set to Falling Edge Trigger
204  */
205 /* Control IRQ / Polling option */
206 static int polling_req;
207 module_param(polling_req, bool, 0444);
208 MODULE_PARM_DESC(polling_req, "Request Polling. Default = 0 (use irq)");
209 
210 /* Control Polling Rate */
211 static int scan_rate = 80;
212 module_param(scan_rate, int, 0644);
213 MODULE_PARM_DESC(scan_rate, "Polling rate in times/sec. Default = 80");
214 
215 /* The main device structure */
216 struct synaptics_i2c {
217 	struct i2c_client	*client;
218 	struct input_dev	*input;
219 	struct delayed_work	dwork;
220 	int			no_data_count;
221 	int			no_decel_param;
222 	int			reduce_report_param;
223 	int			no_filter_param;
224 	int			scan_rate_param;
225 	int			scan_ms;
226 };
227 
228 static inline void set_scan_rate(struct synaptics_i2c *touch, int scan_rate)
229 {
230 	touch->scan_ms = MSEC_PER_SEC / scan_rate;
231 	touch->scan_rate_param = scan_rate;
232 }
233 
234 /*
235  * Driver's initial design makes no race condition possible on i2c bus,
236  * so there is no need in any locking.
237  * Keep it in mind, while playing with the code.
238  */
239 static s32 synaptics_i2c_reg_get(struct i2c_client *client, u16 reg)
240 {
241 	int ret;
242 
243 	ret = i2c_smbus_write_byte_data(client, PAGE_SEL_REG, reg >> 8);
244 	if (ret == 0)
245 		ret = i2c_smbus_read_byte_data(client, reg & 0xff);
246 
247 	return ret;
248 }
249 
250 static s32 synaptics_i2c_reg_set(struct i2c_client *client, u16 reg, u8 val)
251 {
252 	int ret;
253 
254 	ret = i2c_smbus_write_byte_data(client, PAGE_SEL_REG, reg >> 8);
255 	if (ret == 0)
256 		ret = i2c_smbus_write_byte_data(client, reg & 0xff, val);
257 
258 	return ret;
259 }
260 
261 static s32 synaptics_i2c_word_get(struct i2c_client *client, u16 reg)
262 {
263 	int ret;
264 
265 	ret = i2c_smbus_write_byte_data(client, PAGE_SEL_REG, reg >> 8);
266 	if (ret == 0)
267 		ret = i2c_smbus_read_word_data(client, reg & 0xff);
268 
269 	return ret;
270 }
271 
272 static int synaptics_i2c_config(struct i2c_client *client)
273 {
274 	int ret, control;
275 	u8 int_en;
276 
277 	/* set Report Rate to Device Highest (>=80) and Sleep to normal */
278 	ret = synaptics_i2c_reg_set(client, DEV_CONTROL_REG, 0xc1);
279 	if (ret)
280 		return ret;
281 
282 	/* set Interrupt Disable to Func20 / Enable to Func10) */
283 	int_en = (polling_req) ? 0 : INT_ENA_ABS_MSK | INT_ENA_REL_MSK;
284 	ret = synaptics_i2c_reg_set(client, INTERRUPT_EN_REG, int_en);
285 	if (ret)
286 		return ret;
287 
288 	control = synaptics_i2c_reg_get(client, GENERAL_2D_CONTROL_REG);
289 	/* No Deceleration */
290 	control |= no_decel ? 1 << NO_DECELERATION : 0;
291 	/* Reduced Reporting */
292 	control |= reduce_report ? 1 << REDUCE_REPORTING : 0;
293 	/* No Filter */
294 	control |= no_filter ? 1 << NO_FILTER : 0;
295 	ret = synaptics_i2c_reg_set(client, GENERAL_2D_CONTROL_REG, control);
296 	if (ret)
297 		return ret;
298 
299 	return 0;
300 }
301 
302 static int synaptics_i2c_reset_config(struct i2c_client *client)
303 {
304 	int ret;
305 
306 	/* Reset the Touchpad */
307 	ret = synaptics_i2c_reg_set(client, DEV_COMMAND_REG, RESET_COMMAND);
308 	if (ret) {
309 		dev_err(&client->dev, "Unable to reset device\n");
310 	} else {
311 		msleep(SOFT_RESET_DELAY_MS);
312 		ret = synaptics_i2c_config(client);
313 		if (ret)
314 			dev_err(&client->dev, "Unable to config device\n");
315 	}
316 
317 	return ret;
318 }
319 
320 static int synaptics_i2c_check_error(struct i2c_client *client)
321 {
322 	int status, ret = 0;
323 
324 	status = i2c_smbus_read_byte_data(client, DEVICE_STATUS_REG) &
325 		(CONFIGURED_MSK | ERROR_MSK);
326 
327 	if (status != CONFIGURED_MSK)
328 		ret = synaptics_i2c_reset_config(client);
329 
330 	return ret;
331 }
332 
333 static bool synaptics_i2c_get_input(struct synaptics_i2c *touch)
334 {
335 	struct input_dev *input = touch->input;
336 	int xy_delta, gesture;
337 	s32 data;
338 	s8 x_delta, y_delta;
339 
340 	/* Deal with spontanious resets and errors */
341 	if (synaptics_i2c_check_error(touch->client))
342 		return 0;
343 
344 	/* Get Gesture Bit */
345 	data = synaptics_i2c_reg_get(touch->client, DATA_REG0);
346 	gesture = (data >> GESTURE) & 0x1;
347 
348 	/*
349 	 * Get Relative axes. we have to get them in one shot,
350 	 * so we get 2 bytes starting from REL_X_REG.
351 	 */
352 	xy_delta = synaptics_i2c_word_get(touch->client, REL_X_REG) & 0xffff;
353 
354 	/* Separate X from Y */
355 	x_delta = xy_delta & 0xff;
356 	y_delta = (xy_delta >> REGISTER_LENGTH) & 0xff;
357 
358 	/* Report the button event */
359 	input_report_key(input, BTN_LEFT, gesture);
360 
361 	/* Report the deltas */
362 	input_report_rel(input, REL_X, x_delta);
363 	input_report_rel(input, REL_Y, -y_delta);
364 	input_sync(input);
365 
366 	return xy_delta || gesture;
367 }
368 
369 static irqreturn_t synaptics_i2c_irq(int irq, void *dev_id)
370 {
371 	struct synaptics_i2c *touch = dev_id;
372 
373 	/*
374 	 * We want to have the work run immediately but it might have
375 	 * already been scheduled with a delay, that's why we have to
376 	 * cancel it first.
377 	 */
378 	cancel_delayed_work(&touch->dwork);
379 	schedule_delayed_work(&touch->dwork, 0);
380 
381 	return IRQ_HANDLED;
382 }
383 
384 static void synaptics_i2c_check_params(struct synaptics_i2c *touch)
385 {
386 	bool reset = false;
387 
388 	if (scan_rate != touch->scan_rate_param)
389 		set_scan_rate(touch, scan_rate);
390 
391 	if (no_decel != touch->no_decel_param) {
392 		touch->no_decel_param = no_decel;
393 		reset = true;
394 	}
395 
396 	if (no_filter != touch->no_filter_param) {
397 		touch->no_filter_param = no_filter;
398 		reset = true;
399 	}
400 
401 	if (reduce_report != touch->reduce_report_param) {
402 		touch->reduce_report_param = reduce_report;
403 		reset = true;
404 	}
405 
406 	if (reset)
407 		synaptics_i2c_reset_config(touch->client);
408 }
409 
410 /* Control the Device polling rate / Work Handler sleep time */
411 unsigned long synaptics_i2c_adjust_delay(struct synaptics_i2c *touch,
412 					 bool have_data)
413 {
414 	unsigned long delay, nodata_count_thres;
415 
416 	if (polling_req) {
417 		delay = touch->scan_ms;
418 		if (have_data) {
419 			touch->no_data_count = 0;
420 		} else {
421 			nodata_count_thres = NO_DATA_THRES / touch->scan_ms;
422 			if (touch->no_data_count < nodata_count_thres)
423 				touch->no_data_count++;
424 			else
425 				delay = NO_DATA_SLEEP_MSECS;
426 		}
427 		return msecs_to_jiffies(delay);
428 	} else {
429 		delay = msecs_to_jiffies(THREAD_IRQ_SLEEP_MSECS);
430 		return round_jiffies_relative(delay);
431 	}
432 }
433 
434 /* Work Handler */
435 static void synaptics_i2c_work_handler(struct work_struct *work)
436 {
437 	bool have_data;
438 	struct synaptics_i2c *touch =
439 			container_of(work, struct synaptics_i2c, dwork.work);
440 	unsigned long delay;
441 
442 	synaptics_i2c_check_params(touch);
443 
444 	have_data = synaptics_i2c_get_input(touch);
445 	delay = synaptics_i2c_adjust_delay(touch, have_data);
446 
447 	/*
448 	 * While interrupt driven, there is no real need to poll the device.
449 	 * But touchpads are very sensitive, so there could be errors
450 	 * related to physical environment and the attention line isn't
451 	 * neccesarily asserted. In such case we can lose the touchpad.
452 	 * We poll the device once in THREAD_IRQ_SLEEP_SECS and
453 	 * if error is detected, we try to reset and reconfigure the touchpad.
454 	 */
455 	schedule_delayed_work(&touch->dwork, delay);
456 }
457 
458 static int synaptics_i2c_open(struct input_dev *input)
459 {
460 	struct synaptics_i2c *touch = input_get_drvdata(input);
461 	int ret;
462 
463 	ret = synaptics_i2c_reset_config(touch->client);
464 	if (ret)
465 		return ret;
466 
467 	if (polling_req)
468 		schedule_delayed_work(&touch->dwork,
469 				       msecs_to_jiffies(NO_DATA_SLEEP_MSECS));
470 
471 	return 0;
472 }
473 
474 static void synaptics_i2c_close(struct input_dev *input)
475 {
476 	struct synaptics_i2c *touch = input_get_drvdata(input);
477 
478 	if (!polling_req)
479 		synaptics_i2c_reg_set(touch->client, INTERRUPT_EN_REG, 0);
480 
481 	cancel_delayed_work_sync(&touch->dwork);
482 
483 	/* Save some power */
484 	synaptics_i2c_reg_set(touch->client, DEV_CONTROL_REG, DEEP_SLEEP);
485 }
486 
487 static void synaptics_i2c_set_input_params(struct synaptics_i2c *touch)
488 {
489 	struct input_dev *input = touch->input;
490 
491 	input->name = touch->client->name;
492 	input->phys = touch->client->adapter->name;
493 	input->id.bustype = BUS_I2C;
494 	input->id.version = synaptics_i2c_word_get(touch->client,
495 						   INFO_QUERY_REG0);
496 	input->dev.parent = &touch->client->dev;
497 	input->open = synaptics_i2c_open;
498 	input->close = synaptics_i2c_close;
499 	input_set_drvdata(input, touch);
500 
501 	/* Register the device as mouse */
502 	__set_bit(EV_REL, input->evbit);
503 	__set_bit(REL_X, input->relbit);
504 	__set_bit(REL_Y, input->relbit);
505 
506 	/* Register device's buttons and keys */
507 	__set_bit(EV_KEY, input->evbit);
508 	__set_bit(BTN_LEFT, input->keybit);
509 }
510 
511 struct synaptics_i2c *synaptics_i2c_touch_create(struct i2c_client *client)
512 {
513 	struct synaptics_i2c *touch;
514 
515 	touch = kzalloc(sizeof(struct synaptics_i2c), GFP_KERNEL);
516 	if (!touch)
517 		return NULL;
518 
519 	touch->client = client;
520 	touch->no_decel_param = no_decel;
521 	touch->scan_rate_param = scan_rate;
522 	set_scan_rate(touch, scan_rate);
523 	INIT_DELAYED_WORK(&touch->dwork, synaptics_i2c_work_handler);
524 
525 	return touch;
526 }
527 
528 static int __devinit synaptics_i2c_probe(struct i2c_client *client,
529 			       const struct i2c_device_id *dev_id)
530 {
531 	int ret;
532 	struct synaptics_i2c *touch;
533 
534 	touch = synaptics_i2c_touch_create(client);
535 	if (!touch)
536 		return -ENOMEM;
537 
538 	i2c_set_clientdata(client, touch);
539 
540 	ret = synaptics_i2c_reset_config(client);
541 	if (ret)
542 		goto err_mem_free;
543 
544 	if (client->irq < 1)
545 		polling_req = 1;
546 
547 	touch->input = input_allocate_device();
548 	if (!touch->input) {
549 		ret = -ENOMEM;
550 		goto err_mem_free;
551 	}
552 
553 	synaptics_i2c_set_input_params(touch);
554 
555 	if (!polling_req) {
556 		dev_dbg(&touch->client->dev,
557 			 "Requesting IRQ: %d\n", touch->client->irq);
558 
559 		ret = request_irq(touch->client->irq, synaptics_i2c_irq,
560 				  IRQF_DISABLED|IRQ_TYPE_EDGE_FALLING,
561 				  DRIVER_NAME, touch);
562 		if (ret) {
563 			dev_warn(&touch->client->dev,
564 				  "IRQ request failed: %d, "
565 				  "falling back to polling\n", ret);
566 			polling_req = 1;
567 			synaptics_i2c_reg_set(touch->client,
568 					      INTERRUPT_EN_REG, 0);
569 		}
570 	}
571 
572 	if (polling_req)
573 		dev_dbg(&touch->client->dev,
574 			 "Using polling at rate: %d times/sec\n", scan_rate);
575 
576 	/* Register the device in input subsystem */
577 	ret = input_register_device(touch->input);
578 	if (ret) {
579 		dev_err(&client->dev,
580 			 "Input device register failed: %d\n", ret);
581 		goto err_input_free;
582 	}
583 	return 0;
584 
585 err_input_free:
586 	input_free_device(touch->input);
587 err_mem_free:
588 	i2c_set_clientdata(client, NULL);
589 	kfree(touch);
590 
591 	return ret;
592 }
593 
594 static int __devexit synaptics_i2c_remove(struct i2c_client *client)
595 {
596 	struct synaptics_i2c *touch = i2c_get_clientdata(client);
597 
598 	if (!polling_req)
599 		free_irq(touch->client->irq, touch);
600 
601 	input_unregister_device(touch->input);
602 	i2c_set_clientdata(client, NULL);
603 	kfree(touch);
604 
605 	return 0;
606 }
607 
608 #ifdef CONFIG_PM
609 static int synaptics_i2c_suspend(struct i2c_client *client, pm_message_t mesg)
610 {
611 	struct synaptics_i2c *touch = i2c_get_clientdata(client);
612 
613 	cancel_delayed_work_sync(&touch->dwork);
614 
615 	/* Save some power */
616 	synaptics_i2c_reg_set(touch->client, DEV_CONTROL_REG, DEEP_SLEEP);
617 
618 	return 0;
619 }
620 
621 static int synaptics_i2c_resume(struct i2c_client *client)
622 {
623 	int ret;
624 	struct synaptics_i2c *touch = i2c_get_clientdata(client);
625 
626 	ret = synaptics_i2c_reset_config(client);
627 	if (ret)
628 		return ret;
629 
630 	schedule_delayed_work(&touch->dwork,
631 			       msecs_to_jiffies(NO_DATA_SLEEP_MSECS));
632 
633 	return 0;
634 }
635 #else
636 #define synaptics_i2c_suspend	NULL
637 #define synaptics_i2c_resume	NULL
638 #endif
639 
640 static const struct i2c_device_id synaptics_i2c_id_table[] = {
641 	{ "synaptics_i2c", 0 },
642 	{ },
643 };
644 MODULE_DEVICE_TABLE(i2c, synaptics_i2c_id_table);
645 
646 static struct i2c_driver synaptics_i2c_driver = {
647 	.driver = {
648 		.name	= DRIVER_NAME,
649 		.owner	= THIS_MODULE,
650 	},
651 
652 	.probe		= synaptics_i2c_probe,
653 	.remove		= __devexit_p(synaptics_i2c_remove),
654 
655 	.suspend	= synaptics_i2c_suspend,
656 	.resume		= synaptics_i2c_resume,
657 	.id_table	= synaptics_i2c_id_table,
658 };
659 
660 static int __init synaptics_i2c_init(void)
661 {
662 	return i2c_add_driver(&synaptics_i2c_driver);
663 }
664 
665 static void __exit synaptics_i2c_exit(void)
666 {
667 	i2c_del_driver(&synaptics_i2c_driver);
668 }
669 
670 module_init(synaptics_i2c_init);
671 module_exit(synaptics_i2c_exit);
672 
673 MODULE_DESCRIPTION("Synaptics I2C touchpad driver");
674 MODULE_AUTHOR("Mike Rapoport, Igor Grinberg, Compulab");
675 MODULE_LICENSE("GPL");
676 
677