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 #include <linux/slab.h>
21 #include <linux/pm.h>
22 
23 #define DRIVER_NAME		"synaptics_i2c"
24 /* maximum product id is 15 characters */
25 #define PRODUCT_ID_LENGTH	15
26 #define REGISTER_LENGTH		8
27 
28 /*
29  * after soft reset, we should wait for 1 ms
30  * before the device becomes operational
31  */
32 #define SOFT_RESET_DELAY_MS	3
33 /* and after hard reset, we should wait for max 500ms */
34 #define HARD_RESET_DELAY_MS	500
35 
36 /* Registers by SMBus address */
37 #define PAGE_SEL_REG		0xff
38 #define DEVICE_STATUS_REG	0x09
39 
40 /* Registers by RMI address */
41 #define DEV_CONTROL_REG		0x0000
42 #define INTERRUPT_EN_REG	0x0001
43 #define ERR_STAT_REG		0x0002
44 #define INT_REQ_STAT_REG	0x0003
45 #define DEV_COMMAND_REG		0x0004
46 
47 #define RMI_PROT_VER_REG	0x0200
48 #define MANUFACT_ID_REG		0x0201
49 #define PHYS_INT_VER_REG	0x0202
50 #define PROD_PROPERTY_REG	0x0203
51 #define INFO_QUERY_REG0		0x0204
52 #define INFO_QUERY_REG1		(INFO_QUERY_REG0 + 1)
53 #define INFO_QUERY_REG2		(INFO_QUERY_REG0 + 2)
54 #define INFO_QUERY_REG3		(INFO_QUERY_REG0 + 3)
55 
56 #define PRODUCT_ID_REG0		0x0210
57 #define PRODUCT_ID_REG1		(PRODUCT_ID_REG0 + 1)
58 #define PRODUCT_ID_REG2		(PRODUCT_ID_REG0 + 2)
59 #define PRODUCT_ID_REG3		(PRODUCT_ID_REG0 + 3)
60 #define PRODUCT_ID_REG4		(PRODUCT_ID_REG0 + 4)
61 #define PRODUCT_ID_REG5		(PRODUCT_ID_REG0 + 5)
62 #define PRODUCT_ID_REG6		(PRODUCT_ID_REG0 + 6)
63 #define PRODUCT_ID_REG7		(PRODUCT_ID_REG0 + 7)
64 #define PRODUCT_ID_REG8		(PRODUCT_ID_REG0 + 8)
65 #define PRODUCT_ID_REG9		(PRODUCT_ID_REG0 + 9)
66 #define PRODUCT_ID_REG10	(PRODUCT_ID_REG0 + 10)
67 #define PRODUCT_ID_REG11	(PRODUCT_ID_REG0 + 11)
68 #define PRODUCT_ID_REG12	(PRODUCT_ID_REG0 + 12)
69 #define PRODUCT_ID_REG13	(PRODUCT_ID_REG0 + 13)
70 #define PRODUCT_ID_REG14	(PRODUCT_ID_REG0 + 14)
71 #define PRODUCT_ID_REG15	(PRODUCT_ID_REG0 + 15)
72 
73 #define DATA_REG0		0x0400
74 #define ABS_PRESSURE_REG	0x0401
75 #define ABS_MSB_X_REG		0x0402
76 #define ABS_LSB_X_REG		(ABS_MSB_X_REG + 1)
77 #define ABS_MSB_Y_REG		0x0404
78 #define ABS_LSB_Y_REG		(ABS_MSB_Y_REG + 1)
79 #define REL_X_REG		0x0406
80 #define REL_Y_REG		0x0407
81 
82 #define DEV_QUERY_REG0		0x1000
83 #define DEV_QUERY_REG1		(DEV_QUERY_REG0 + 1)
84 #define DEV_QUERY_REG2		(DEV_QUERY_REG0 + 2)
85 #define DEV_QUERY_REG3		(DEV_QUERY_REG0 + 3)
86 #define DEV_QUERY_REG4		(DEV_QUERY_REG0 + 4)
87 #define DEV_QUERY_REG5		(DEV_QUERY_REG0 + 5)
88 #define DEV_QUERY_REG6		(DEV_QUERY_REG0 + 6)
89 #define DEV_QUERY_REG7		(DEV_QUERY_REG0 + 7)
90 #define DEV_QUERY_REG8		(DEV_QUERY_REG0 + 8)
91 
92 #define GENERAL_2D_CONTROL_REG	0x1041
93 #define SENSOR_SENSITIVITY_REG	0x1044
94 #define SENS_MAX_POS_MSB_REG	0x1046
95 #define SENS_MAX_POS_LSB_REG	(SENS_MAX_POS_UPPER_REG + 1)
96 
97 /* Register bits */
98 /* Device Control Register Bits */
99 #define REPORT_RATE_1ST_BIT	6
100 
101 /* Interrupt Enable Register Bits (INTERRUPT_EN_REG) */
102 #define F10_ABS_INT_ENA		0
103 #define F10_REL_INT_ENA		1
104 #define F20_INT_ENA		2
105 
106 /* Interrupt Request Register Bits (INT_REQ_STAT_REG | DEVICE_STATUS_REG) */
107 #define F10_ABS_INT_REQ		0
108 #define F10_REL_INT_REQ		1
109 #define F20_INT_REQ		2
110 /* Device Status Register Bits (DEVICE_STATUS_REG) */
111 #define STAT_CONFIGURED		6
112 #define STAT_ERROR		7
113 
114 /* Device Command Register Bits (DEV_COMMAND_REG) */
115 #define RESET_COMMAND		0x01
116 #define REZERO_COMMAND		0x02
117 
118 /* Data Register 0 Bits (DATA_REG0) */
119 #define GESTURE			3
120 
121 /* Device Query Registers Bits */
122 /* DEV_QUERY_REG3 */
123 #define HAS_PALM_DETECT		1
124 #define HAS_MULTI_FING		2
125 #define HAS_SCROLLER		4
126 #define HAS_2D_SCROLL		5
127 
128 /* General 2D Control Register Bits (GENERAL_2D_CONTROL_REG) */
129 #define NO_DECELERATION		1
130 #define REDUCE_REPORTING	3
131 #define NO_FILTER		5
132 
133 /* Function Masks */
134 /* Device Control Register Masks (DEV_CONTROL_REG) */
135 #define REPORT_RATE_MSK		0xc0
136 #define SLEEP_MODE_MSK		0x07
137 
138 /* Device Sleep Modes */
139 #define FULL_AWAKE		0x0
140 #define NORMAL_OP		0x1
141 #define LOW_PWR_OP		0x2
142 #define VERY_LOW_PWR_OP		0x3
143 #define SENS_SLEEP		0x4
144 #define SLEEP_MOD		0x5
145 #define DEEP_SLEEP		0x6
146 #define HIBERNATE		0x7
147 
148 /* Interrupt Register Mask */
149 /* (INT_REQ_STAT_REG | DEVICE_STATUS_REG | INTERRUPT_EN_REG) */
150 #define INT_ENA_REQ_MSK		0x07
151 #define INT_ENA_ABS_MSK		0x01
152 #define INT_ENA_REL_MSK		0x02
153 #define INT_ENA_F20_MSK		0x04
154 
155 /* Device Status Register Masks (DEVICE_STATUS_REG) */
156 #define CONFIGURED_MSK		0x40
157 #define ERROR_MSK		0x80
158 
159 /* Data Register 0 Masks */
160 #define FINGER_WIDTH_MSK	0xf0
161 #define GESTURE_MSK		0x08
162 #define SENSOR_STATUS_MSK	0x07
163 
164 /*
165  * MSB Position Register Masks
166  * ABS_MSB_X_REG | ABS_MSB_Y_REG | SENS_MAX_POS_MSB_REG |
167  * DEV_QUERY_REG3 | DEV_QUERY_REG5
168  */
169 #define MSB_POSITION_MSK	0x1f
170 
171 /* Device Query Registers Masks */
172 
173 /* DEV_QUERY_REG2 */
174 #define NUM_EXTRA_POS_MSK	0x07
175 
176 /* When in IRQ mode read the device every THREAD_IRQ_SLEEP_SECS */
177 #define THREAD_IRQ_SLEEP_SECS	2
178 #define THREAD_IRQ_SLEEP_MSECS	(THREAD_IRQ_SLEEP_SECS * MSEC_PER_SEC)
179 
180 /*
181  * When in Polling mode and no data received for NO_DATA_THRES msecs
182  * reduce the polling rate to NO_DATA_SLEEP_MSECS
183  */
184 #define NO_DATA_THRES		(MSEC_PER_SEC)
185 #define NO_DATA_SLEEP_MSECS	(MSEC_PER_SEC / 4)
186 
187 /* Control touchpad's No Deceleration option */
188 static bool no_decel = true;
189 module_param(no_decel, bool, 0644);
190 MODULE_PARM_DESC(no_decel, "No Deceleration. Default = 1 (on)");
191 
192 /* Control touchpad's Reduced Reporting option */
193 static bool reduce_report;
194 module_param(reduce_report, bool, 0644);
195 MODULE_PARM_DESC(reduce_report, "Reduced Reporting. Default = 0 (off)");
196 
197 /* Control touchpad's No Filter option */
198 static bool no_filter;
199 module_param(no_filter, bool, 0644);
200 MODULE_PARM_DESC(no_filter, "No Filter. Default = 0 (off)");
201 
202 /*
203  * touchpad Attention line is Active Low and Open Drain,
204  * therefore should be connected to pulled up line
205  * and the irq configuration should be set to Falling Edge Trigger
206  */
207 /* Control IRQ / Polling option */
208 static bool polling_req;
209 module_param(polling_req, bool, 0444);
210 MODULE_PARM_DESC(polling_req, "Request Polling. Default = 0 (use irq)");
211 
212 /* Control Polling Rate */
213 static int scan_rate = 80;
214 module_param(scan_rate, int, 0644);
215 MODULE_PARM_DESC(scan_rate, "Polling rate in times/sec. Default = 80");
216 
217 /* The main device structure */
218 struct synaptics_i2c {
219 	struct i2c_client	*client;
220 	struct input_dev	*input;
221 	struct delayed_work	dwork;
222 	spinlock_t		lock;
223 	int			no_data_count;
224 	int			no_decel_param;
225 	int			reduce_report_param;
226 	int			no_filter_param;
227 	int			scan_rate_param;
228 	int			scan_ms;
229 };
230 
231 static inline void set_scan_rate(struct synaptics_i2c *touch, int scan_rate)
232 {
233 	touch->scan_ms = MSEC_PER_SEC / scan_rate;
234 	touch->scan_rate_param = scan_rate;
235 }
236 
237 /*
238  * Driver's initial design makes no race condition possible on i2c bus,
239  * so there is no need in any locking.
240  * Keep it in mind, while playing with the code.
241  */
242 static s32 synaptics_i2c_reg_get(struct i2c_client *client, u16 reg)
243 {
244 	int ret;
245 
246 	ret = i2c_smbus_write_byte_data(client, PAGE_SEL_REG, reg >> 8);
247 	if (ret == 0)
248 		ret = i2c_smbus_read_byte_data(client, reg & 0xff);
249 
250 	return ret;
251 }
252 
253 static s32 synaptics_i2c_reg_set(struct i2c_client *client, u16 reg, u8 val)
254 {
255 	int ret;
256 
257 	ret = i2c_smbus_write_byte_data(client, PAGE_SEL_REG, reg >> 8);
258 	if (ret == 0)
259 		ret = i2c_smbus_write_byte_data(client, reg & 0xff, val);
260 
261 	return ret;
262 }
263 
264 static s32 synaptics_i2c_word_get(struct i2c_client *client, u16 reg)
265 {
266 	int ret;
267 
268 	ret = i2c_smbus_write_byte_data(client, PAGE_SEL_REG, reg >> 8);
269 	if (ret == 0)
270 		ret = i2c_smbus_read_word_data(client, reg & 0xff);
271 
272 	return ret;
273 }
274 
275 static int synaptics_i2c_config(struct i2c_client *client)
276 {
277 	int ret, control;
278 	u8 int_en;
279 
280 	/* set Report Rate to Device Highest (>=80) and Sleep to normal */
281 	ret = synaptics_i2c_reg_set(client, DEV_CONTROL_REG, 0xc1);
282 	if (ret)
283 		return ret;
284 
285 	/* set Interrupt Disable to Func20 / Enable to Func10) */
286 	int_en = (polling_req) ? 0 : INT_ENA_ABS_MSK | INT_ENA_REL_MSK;
287 	ret = synaptics_i2c_reg_set(client, INTERRUPT_EN_REG, int_en);
288 	if (ret)
289 		return ret;
290 
291 	control = synaptics_i2c_reg_get(client, GENERAL_2D_CONTROL_REG);
292 	/* No Deceleration */
293 	control |= no_decel ? 1 << NO_DECELERATION : 0;
294 	/* Reduced Reporting */
295 	control |= reduce_report ? 1 << REDUCE_REPORTING : 0;
296 	/* No Filter */
297 	control |= no_filter ? 1 << NO_FILTER : 0;
298 	ret = synaptics_i2c_reg_set(client, GENERAL_2D_CONTROL_REG, control);
299 	if (ret)
300 		return ret;
301 
302 	return 0;
303 }
304 
305 static int synaptics_i2c_reset_config(struct i2c_client *client)
306 {
307 	int ret;
308 
309 	/* Reset the Touchpad */
310 	ret = synaptics_i2c_reg_set(client, DEV_COMMAND_REG, RESET_COMMAND);
311 	if (ret) {
312 		dev_err(&client->dev, "Unable to reset device\n");
313 	} else {
314 		msleep(SOFT_RESET_DELAY_MS);
315 		ret = synaptics_i2c_config(client);
316 		if (ret)
317 			dev_err(&client->dev, "Unable to config device\n");
318 	}
319 
320 	return ret;
321 }
322 
323 static int synaptics_i2c_check_error(struct i2c_client *client)
324 {
325 	int status, ret = 0;
326 
327 	status = i2c_smbus_read_byte_data(client, DEVICE_STATUS_REG) &
328 		(CONFIGURED_MSK | ERROR_MSK);
329 
330 	if (status != CONFIGURED_MSK)
331 		ret = synaptics_i2c_reset_config(client);
332 
333 	return ret;
334 }
335 
336 static bool synaptics_i2c_get_input(struct synaptics_i2c *touch)
337 {
338 	struct input_dev *input = touch->input;
339 	int xy_delta, gesture;
340 	s32 data;
341 	s8 x_delta, y_delta;
342 
343 	/* Deal with spontaneous resets and errors */
344 	if (synaptics_i2c_check_error(touch->client))
345 		return false;
346 
347 	/* Get Gesture Bit */
348 	data = synaptics_i2c_reg_get(touch->client, DATA_REG0);
349 	gesture = (data >> GESTURE) & 0x1;
350 
351 	/*
352 	 * Get Relative axes. we have to get them in one shot,
353 	 * so we get 2 bytes starting from REL_X_REG.
354 	 */
355 	xy_delta = synaptics_i2c_word_get(touch->client, REL_X_REG) & 0xffff;
356 
357 	/* Separate X from Y */
358 	x_delta = xy_delta & 0xff;
359 	y_delta = (xy_delta >> REGISTER_LENGTH) & 0xff;
360 
361 	/* Report the button event */
362 	input_report_key(input, BTN_LEFT, gesture);
363 
364 	/* Report the deltas */
365 	input_report_rel(input, REL_X, x_delta);
366 	input_report_rel(input, REL_Y, -y_delta);
367 	input_sync(input);
368 
369 	return xy_delta || gesture;
370 }
371 
372 static void synaptics_i2c_reschedule_work(struct synaptics_i2c *touch,
373 					  unsigned long delay)
374 {
375 	unsigned long flags;
376 
377 	spin_lock_irqsave(&touch->lock, flags);
378 
379 	mod_delayed_work(system_wq, &touch->dwork, delay);
380 
381 	spin_unlock_irqrestore(&touch->lock, flags);
382 }
383 
384 static irqreturn_t synaptics_i2c_irq(int irq, void *dev_id)
385 {
386 	struct synaptics_i2c *touch = dev_id;
387 
388 	synaptics_i2c_reschedule_work(touch, 0);
389 
390 	return IRQ_HANDLED;
391 }
392 
393 static void synaptics_i2c_check_params(struct synaptics_i2c *touch)
394 {
395 	bool reset = false;
396 
397 	if (scan_rate != touch->scan_rate_param)
398 		set_scan_rate(touch, scan_rate);
399 
400 	if (no_decel != touch->no_decel_param) {
401 		touch->no_decel_param = no_decel;
402 		reset = true;
403 	}
404 
405 	if (no_filter != touch->no_filter_param) {
406 		touch->no_filter_param = no_filter;
407 		reset = true;
408 	}
409 
410 	if (reduce_report != touch->reduce_report_param) {
411 		touch->reduce_report_param = reduce_report;
412 		reset = true;
413 	}
414 
415 	if (reset)
416 		synaptics_i2c_reset_config(touch->client);
417 }
418 
419 /* Control the Device polling rate / Work Handler sleep time */
420 static unsigned long synaptics_i2c_adjust_delay(struct synaptics_i2c *touch,
421 						bool have_data)
422 {
423 	unsigned long delay, nodata_count_thres;
424 
425 	if (polling_req) {
426 		delay = touch->scan_ms;
427 		if (have_data) {
428 			touch->no_data_count = 0;
429 		} else {
430 			nodata_count_thres = NO_DATA_THRES / touch->scan_ms;
431 			if (touch->no_data_count < nodata_count_thres)
432 				touch->no_data_count++;
433 			else
434 				delay = NO_DATA_SLEEP_MSECS;
435 		}
436 		return msecs_to_jiffies(delay);
437 	} else {
438 		delay = msecs_to_jiffies(THREAD_IRQ_SLEEP_MSECS);
439 		return round_jiffies_relative(delay);
440 	}
441 }
442 
443 /* Work Handler */
444 static void synaptics_i2c_work_handler(struct work_struct *work)
445 {
446 	bool have_data;
447 	struct synaptics_i2c *touch =
448 			container_of(work, struct synaptics_i2c, dwork.work);
449 	unsigned long delay;
450 
451 	synaptics_i2c_check_params(touch);
452 
453 	have_data = synaptics_i2c_get_input(touch);
454 	delay = synaptics_i2c_adjust_delay(touch, have_data);
455 
456 	/*
457 	 * While interrupt driven, there is no real need to poll the device.
458 	 * But touchpads are very sensitive, so there could be errors
459 	 * related to physical environment and the attention line isn't
460 	 * necessarily asserted. In such case we can lose the touchpad.
461 	 * We poll the device once in THREAD_IRQ_SLEEP_SECS and
462 	 * if error is detected, we try to reset and reconfigure the touchpad.
463 	 */
464 	synaptics_i2c_reschedule_work(touch, delay);
465 }
466 
467 static int synaptics_i2c_open(struct input_dev *input)
468 {
469 	struct synaptics_i2c *touch = input_get_drvdata(input);
470 	int ret;
471 
472 	ret = synaptics_i2c_reset_config(touch->client);
473 	if (ret)
474 		return ret;
475 
476 	if (polling_req)
477 		synaptics_i2c_reschedule_work(touch,
478 				msecs_to_jiffies(NO_DATA_SLEEP_MSECS));
479 
480 	return 0;
481 }
482 
483 static void synaptics_i2c_close(struct input_dev *input)
484 {
485 	struct synaptics_i2c *touch = input_get_drvdata(input);
486 
487 	if (!polling_req)
488 		synaptics_i2c_reg_set(touch->client, INTERRUPT_EN_REG, 0);
489 
490 	cancel_delayed_work_sync(&touch->dwork);
491 
492 	/* Save some power */
493 	synaptics_i2c_reg_set(touch->client, DEV_CONTROL_REG, DEEP_SLEEP);
494 }
495 
496 static void synaptics_i2c_set_input_params(struct synaptics_i2c *touch)
497 {
498 	struct input_dev *input = touch->input;
499 
500 	input->name = touch->client->name;
501 	input->phys = touch->client->adapter->name;
502 	input->id.bustype = BUS_I2C;
503 	input->id.version = synaptics_i2c_word_get(touch->client,
504 						   INFO_QUERY_REG0);
505 	input->dev.parent = &touch->client->dev;
506 	input->open = synaptics_i2c_open;
507 	input->close = synaptics_i2c_close;
508 	input_set_drvdata(input, touch);
509 
510 	/* Register the device as mouse */
511 	__set_bit(EV_REL, input->evbit);
512 	__set_bit(REL_X, input->relbit);
513 	__set_bit(REL_Y, input->relbit);
514 
515 	/* Register device's buttons and keys */
516 	__set_bit(EV_KEY, input->evbit);
517 	__set_bit(BTN_LEFT, input->keybit);
518 }
519 
520 static struct synaptics_i2c *synaptics_i2c_touch_create(struct i2c_client *client)
521 {
522 	struct synaptics_i2c *touch;
523 
524 	touch = kzalloc(sizeof(struct synaptics_i2c), GFP_KERNEL);
525 	if (!touch)
526 		return NULL;
527 
528 	touch->client = client;
529 	touch->no_decel_param = no_decel;
530 	touch->scan_rate_param = scan_rate;
531 	set_scan_rate(touch, scan_rate);
532 	INIT_DELAYED_WORK(&touch->dwork, synaptics_i2c_work_handler);
533 	spin_lock_init(&touch->lock);
534 
535 	return touch;
536 }
537 
538 static int synaptics_i2c_probe(struct i2c_client *client,
539 			       const struct i2c_device_id *dev_id)
540 {
541 	int ret;
542 	struct synaptics_i2c *touch;
543 
544 	touch = synaptics_i2c_touch_create(client);
545 	if (!touch)
546 		return -ENOMEM;
547 
548 	ret = synaptics_i2c_reset_config(client);
549 	if (ret)
550 		goto err_mem_free;
551 
552 	if (client->irq < 1)
553 		polling_req = true;
554 
555 	touch->input = input_allocate_device();
556 	if (!touch->input) {
557 		ret = -ENOMEM;
558 		goto err_mem_free;
559 	}
560 
561 	synaptics_i2c_set_input_params(touch);
562 
563 	if (!polling_req) {
564 		dev_dbg(&touch->client->dev,
565 			 "Requesting IRQ: %d\n", touch->client->irq);
566 
567 		ret = request_irq(touch->client->irq, synaptics_i2c_irq,
568 				  IRQ_TYPE_EDGE_FALLING,
569 				  DRIVER_NAME, touch);
570 		if (ret) {
571 			dev_warn(&touch->client->dev,
572 				  "IRQ request failed: %d, "
573 				  "falling back to polling\n", ret);
574 			polling_req = true;
575 			synaptics_i2c_reg_set(touch->client,
576 					      INTERRUPT_EN_REG, 0);
577 		}
578 	}
579 
580 	if (polling_req)
581 		dev_dbg(&touch->client->dev,
582 			 "Using polling at rate: %d times/sec\n", scan_rate);
583 
584 	/* Register the device in input subsystem */
585 	ret = input_register_device(touch->input);
586 	if (ret) {
587 		dev_err(&client->dev,
588 			 "Input device register failed: %d\n", ret);
589 		goto err_input_free;
590 	}
591 
592 	i2c_set_clientdata(client, touch);
593 
594 	return 0;
595 
596 err_input_free:
597 	input_free_device(touch->input);
598 err_mem_free:
599 	kfree(touch);
600 
601 	return ret;
602 }
603 
604 static int synaptics_i2c_remove(struct i2c_client *client)
605 {
606 	struct synaptics_i2c *touch = i2c_get_clientdata(client);
607 
608 	if (!polling_req)
609 		free_irq(client->irq, touch);
610 
611 	input_unregister_device(touch->input);
612 	kfree(touch);
613 
614 	return 0;
615 }
616 
617 static int __maybe_unused synaptics_i2c_suspend(struct device *dev)
618 {
619 	struct i2c_client *client = to_i2c_client(dev);
620 	struct synaptics_i2c *touch = i2c_get_clientdata(client);
621 
622 	cancel_delayed_work_sync(&touch->dwork);
623 
624 	/* Save some power */
625 	synaptics_i2c_reg_set(touch->client, DEV_CONTROL_REG, DEEP_SLEEP);
626 
627 	return 0;
628 }
629 
630 static int __maybe_unused synaptics_i2c_resume(struct device *dev)
631 {
632 	int ret;
633 	struct i2c_client *client = to_i2c_client(dev);
634 	struct synaptics_i2c *touch = i2c_get_clientdata(client);
635 
636 	ret = synaptics_i2c_reset_config(client);
637 	if (ret)
638 		return ret;
639 
640 	synaptics_i2c_reschedule_work(touch,
641 				msecs_to_jiffies(NO_DATA_SLEEP_MSECS));
642 
643 	return 0;
644 }
645 
646 static SIMPLE_DEV_PM_OPS(synaptics_i2c_pm, synaptics_i2c_suspend,
647 			 synaptics_i2c_resume);
648 
649 static const struct i2c_device_id synaptics_i2c_id_table[] = {
650 	{ "synaptics_i2c", 0 },
651 	{ },
652 };
653 MODULE_DEVICE_TABLE(i2c, synaptics_i2c_id_table);
654 
655 static struct i2c_driver synaptics_i2c_driver = {
656 	.driver = {
657 		.name	= DRIVER_NAME,
658 		.pm	= &synaptics_i2c_pm,
659 	},
660 
661 	.probe		= synaptics_i2c_probe,
662 	.remove		= synaptics_i2c_remove,
663 
664 	.id_table	= synaptics_i2c_id_table,
665 };
666 
667 module_i2c_driver(synaptics_i2c_driver);
668 
669 MODULE_DESCRIPTION("Synaptics I2C touchpad driver");
670 MODULE_AUTHOR("Mike Rapoport, Igor Grinberg, Compulab");
671 MODULE_LICENSE("GPL");
672 
673