1/*
2 * AD714X CapTouch Programmable Controller driver supporting AD7142/3/7/8/7A
3 *
4 * Copyright 2009-2011 Analog Devices Inc.
5 *
6 * Licensed under the GPL-2 or later.
7 */
8
9#include <linux/device.h>
10#include <linux/input.h>
11#include <linux/interrupt.h>
12#include <linux/slab.h>
13#include <linux/input/ad714x.h>
14#include <linux/module.h>
15#include "ad714x.h"
16
17#define AD714X_PWR_CTRL           0x0
18#define AD714X_STG_CAL_EN_REG     0x1
19#define AD714X_AMB_COMP_CTRL0_REG 0x2
20#define AD714X_PARTID_REG         0x17
21#define AD7142_PARTID             0xE620
22#define AD7143_PARTID             0xE630
23#define AD7147_PARTID             0x1470
24#define AD7148_PARTID             0x1480
25#define AD714X_STAGECFG_REG       0x80
26#define AD714X_SYSCFG_REG         0x0
27
28#define STG_LOW_INT_EN_REG     0x5
29#define STG_HIGH_INT_EN_REG    0x6
30#define STG_COM_INT_EN_REG     0x7
31#define STG_LOW_INT_STA_REG    0x8
32#define STG_HIGH_INT_STA_REG   0x9
33#define STG_COM_INT_STA_REG    0xA
34
35#define CDC_RESULT_S0          0xB
36#define CDC_RESULT_S1          0xC
37#define CDC_RESULT_S2          0xD
38#define CDC_RESULT_S3          0xE
39#define CDC_RESULT_S4          0xF
40#define CDC_RESULT_S5          0x10
41#define CDC_RESULT_S6          0x11
42#define CDC_RESULT_S7          0x12
43#define CDC_RESULT_S8          0x13
44#define CDC_RESULT_S9          0x14
45#define CDC_RESULT_S10         0x15
46#define CDC_RESULT_S11         0x16
47
48#define STAGE0_AMBIENT		0xF1
49#define STAGE1_AMBIENT		0x115
50#define STAGE2_AMBIENT		0x139
51#define STAGE3_AMBIENT		0x15D
52#define STAGE4_AMBIENT		0x181
53#define STAGE5_AMBIENT		0x1A5
54#define STAGE6_AMBIENT		0x1C9
55#define STAGE7_AMBIENT		0x1ED
56#define STAGE8_AMBIENT		0x211
57#define STAGE9_AMBIENT		0x234
58#define STAGE10_AMBIENT		0x259
59#define STAGE11_AMBIENT		0x27D
60
61#define PER_STAGE_REG_NUM      36
62#define STAGE_CFGREG_NUM       8
63#define SYS_CFGREG_NUM         8
64
65/*
66 * driver information which will be used to maintain the software flow
67 */
68enum ad714x_device_state { IDLE, JITTER, ACTIVE, SPACE };
69
70struct ad714x_slider_drv {
71	int highest_stage;
72	int abs_pos;
73	int flt_pos;
74	enum ad714x_device_state state;
75	struct input_dev *input;
76};
77
78struct ad714x_wheel_drv {
79	int abs_pos;
80	int flt_pos;
81	int pre_highest_stage;
82	int highest_stage;
83	enum ad714x_device_state state;
84	struct input_dev *input;
85};
86
87struct ad714x_touchpad_drv {
88	int x_highest_stage;
89	int x_flt_pos;
90	int x_abs_pos;
91	int y_highest_stage;
92	int y_flt_pos;
93	int y_abs_pos;
94	int left_ep;
95	int left_ep_val;
96	int right_ep;
97	int right_ep_val;
98	int top_ep;
99	int top_ep_val;
100	int bottom_ep;
101	int bottom_ep_val;
102	enum ad714x_device_state state;
103	struct input_dev *input;
104};
105
106struct ad714x_button_drv {
107	enum ad714x_device_state state;
108	/*
109	 * Unlike slider/wheel/touchpad, all buttons point to
110	 * same input_dev instance
111	 */
112	struct input_dev *input;
113};
114
115struct ad714x_driver_data {
116	struct ad714x_slider_drv *slider;
117	struct ad714x_wheel_drv *wheel;
118	struct ad714x_touchpad_drv *touchpad;
119	struct ad714x_button_drv *button;
120};
121
122/*
123 * information to integrate all things which will be private data
124 * of spi/i2c device
125 */
126
127static void ad714x_use_com_int(struct ad714x_chip *ad714x,
128				int start_stage, int end_stage)
129{
130	unsigned short data;
131	unsigned short mask;
132
133	mask = ((1 << (end_stage + 1)) - 1) - ((1 << start_stage) - 1);
134
135	ad714x->read(ad714x, STG_COM_INT_EN_REG, &data, 1);
136	data |= 1 << end_stage;
137	ad714x->write(ad714x, STG_COM_INT_EN_REG, data);
138
139	ad714x->read(ad714x, STG_HIGH_INT_EN_REG, &data, 1);
140	data &= ~mask;
141	ad714x->write(ad714x, STG_HIGH_INT_EN_REG, data);
142}
143
144static void ad714x_use_thr_int(struct ad714x_chip *ad714x,
145				int start_stage, int end_stage)
146{
147	unsigned short data;
148	unsigned short mask;
149
150	mask = ((1 << (end_stage + 1)) - 1) - ((1 << start_stage) - 1);
151
152	ad714x->read(ad714x, STG_COM_INT_EN_REG, &data, 1);
153	data &= ~(1 << end_stage);
154	ad714x->write(ad714x, STG_COM_INT_EN_REG, data);
155
156	ad714x->read(ad714x, STG_HIGH_INT_EN_REG, &data, 1);
157	data |= mask;
158	ad714x->write(ad714x, STG_HIGH_INT_EN_REG, data);
159}
160
161static int ad714x_cal_highest_stage(struct ad714x_chip *ad714x,
162					int start_stage, int end_stage)
163{
164	int max_res = 0;
165	int max_idx = 0;
166	int i;
167
168	for (i = start_stage; i <= end_stage; i++) {
169		if (ad714x->sensor_val[i] > max_res) {
170			max_res = ad714x->sensor_val[i];
171			max_idx = i;
172		}
173	}
174
175	return max_idx;
176}
177
178static int ad714x_cal_abs_pos(struct ad714x_chip *ad714x,
179				int start_stage, int end_stage,
180				int highest_stage, int max_coord)
181{
182	int a_param, b_param;
183
184	if (highest_stage == start_stage) {
185		a_param = ad714x->sensor_val[start_stage + 1];
186		b_param = ad714x->sensor_val[start_stage] +
187			ad714x->sensor_val[start_stage + 1];
188	} else if (highest_stage == end_stage) {
189		a_param = ad714x->sensor_val[end_stage] *
190			(end_stage - start_stage) +
191			ad714x->sensor_val[end_stage - 1] *
192			(end_stage - start_stage - 1);
193		b_param = ad714x->sensor_val[end_stage] +
194			ad714x->sensor_val[end_stage - 1];
195	} else {
196		a_param = ad714x->sensor_val[highest_stage] *
197			(highest_stage - start_stage) +
198			ad714x->sensor_val[highest_stage - 1] *
199			(highest_stage - start_stage - 1) +
200			ad714x->sensor_val[highest_stage + 1] *
201			(highest_stage - start_stage + 1);
202		b_param = ad714x->sensor_val[highest_stage] +
203			ad714x->sensor_val[highest_stage - 1] +
204			ad714x->sensor_val[highest_stage + 1];
205	}
206
207	return (max_coord / (end_stage - start_stage)) * a_param / b_param;
208}
209
210/*
211 * One button can connect to multi positive and negative of CDCs
212 * Multi-buttons can connect to same positive/negative of one CDC
213 */
214static void ad714x_button_state_machine(struct ad714x_chip *ad714x, int idx)
215{
216	struct ad714x_button_plat *hw = &ad714x->hw->button[idx];
217	struct ad714x_button_drv *sw = &ad714x->sw->button[idx];
218
219	switch (sw->state) {
220	case IDLE:
221		if (((ad714x->h_state & hw->h_mask) == hw->h_mask) &&
222		    ((ad714x->l_state & hw->l_mask) == hw->l_mask)) {
223			dev_dbg(ad714x->dev, "button %d touched\n", idx);
224			input_report_key(sw->input, hw->keycode, 1);
225			input_sync(sw->input);
226			sw->state = ACTIVE;
227		}
228		break;
229
230	case ACTIVE:
231		if (((ad714x->h_state & hw->h_mask) != hw->h_mask) ||
232		    ((ad714x->l_state & hw->l_mask) != hw->l_mask)) {
233			dev_dbg(ad714x->dev, "button %d released\n", idx);
234			input_report_key(sw->input, hw->keycode, 0);
235			input_sync(sw->input);
236			sw->state = IDLE;
237		}
238		break;
239
240	default:
241		break;
242	}
243}
244
245/*
246 * The response of a sensor is defined by the absolute number of codes
247 * between the current CDC value and the ambient value.
248 */
249static void ad714x_slider_cal_sensor_val(struct ad714x_chip *ad714x, int idx)
250{
251	struct ad714x_slider_plat *hw = &ad714x->hw->slider[idx];
252	int i;
253
254	ad714x->read(ad714x, CDC_RESULT_S0 + hw->start_stage,
255			&ad714x->adc_reg[hw->start_stage],
256			hw->end_stage - hw->start_stage + 1);
257
258	for (i = hw->start_stage; i <= hw->end_stage; i++) {
259		ad714x->read(ad714x, STAGE0_AMBIENT + i * PER_STAGE_REG_NUM,
260				&ad714x->amb_reg[i], 1);
261
262		ad714x->sensor_val[i] =
263			abs(ad714x->adc_reg[i] - ad714x->amb_reg[i]);
264	}
265}
266
267static void ad714x_slider_cal_highest_stage(struct ad714x_chip *ad714x, int idx)
268{
269	struct ad714x_slider_plat *hw = &ad714x->hw->slider[idx];
270	struct ad714x_slider_drv *sw = &ad714x->sw->slider[idx];
271
272	sw->highest_stage = ad714x_cal_highest_stage(ad714x, hw->start_stage,
273			hw->end_stage);
274
275	dev_dbg(ad714x->dev, "slider %d highest_stage:%d\n", idx,
276		sw->highest_stage);
277}
278
279/*
280 * The formulae are very straight forward. It uses the sensor with the
281 * highest response and the 2 adjacent ones.
282 * When Sensor 0 has the highest response, only sensor 0 and sensor 1
283 * are used in the calculations. Similarly when the last sensor has the
284 * highest response, only the last sensor and the second last sensors
285 * are used in the calculations.
286 *
287 * For i= idx_of_peak_Sensor-1 to i= idx_of_peak_Sensor+1
288 *         v += Sensor response(i)*i
289 *         w += Sensor response(i)
290 * POS=(Number_of_Positions_Wanted/(Number_of_Sensors_Used-1)) *(v/w)
291 */
292static void ad714x_slider_cal_abs_pos(struct ad714x_chip *ad714x, int idx)
293{
294	struct ad714x_slider_plat *hw = &ad714x->hw->slider[idx];
295	struct ad714x_slider_drv *sw = &ad714x->sw->slider[idx];
296
297	sw->abs_pos = ad714x_cal_abs_pos(ad714x, hw->start_stage, hw->end_stage,
298		sw->highest_stage, hw->max_coord);
299
300	dev_dbg(ad714x->dev, "slider %d absolute position:%d\n", idx,
301		sw->abs_pos);
302}
303
304/*
305 * To minimise the Impact of the noise on the algorithm, ADI developed a
306 * routine that filters the CDC results after they have been read by the
307 * host processor.
308 * The filter used is an Infinite Input Response(IIR) filter implemented
309 * in firmware and attenuates the noise on the CDC results after they've
310 * been read by the host processor.
311 * Filtered_CDC_result = (Filtered_CDC_result * (10 - Coefficient) +
312 *				Latest_CDC_result * Coefficient)/10
313 */
314static void ad714x_slider_cal_flt_pos(struct ad714x_chip *ad714x, int idx)
315{
316	struct ad714x_slider_drv *sw = &ad714x->sw->slider[idx];
317
318	sw->flt_pos = (sw->flt_pos * (10 - 4) +
319			sw->abs_pos * 4)/10;
320
321	dev_dbg(ad714x->dev, "slider %d filter position:%d\n", idx,
322		sw->flt_pos);
323}
324
325static void ad714x_slider_use_com_int(struct ad714x_chip *ad714x, int idx)
326{
327	struct ad714x_slider_plat *hw = &ad714x->hw->slider[idx];
328
329	ad714x_use_com_int(ad714x, hw->start_stage, hw->end_stage);
330}
331
332static void ad714x_slider_use_thr_int(struct ad714x_chip *ad714x, int idx)
333{
334	struct ad714x_slider_plat *hw = &ad714x->hw->slider[idx];
335
336	ad714x_use_thr_int(ad714x, hw->start_stage, hw->end_stage);
337}
338
339static void ad714x_slider_state_machine(struct ad714x_chip *ad714x, int idx)
340{
341	struct ad714x_slider_plat *hw = &ad714x->hw->slider[idx];
342	struct ad714x_slider_drv *sw = &ad714x->sw->slider[idx];
343	unsigned short h_state, c_state;
344	unsigned short mask;
345
346	mask = ((1 << (hw->end_stage + 1)) - 1) - ((1 << hw->start_stage) - 1);
347
348	h_state = ad714x->h_state & mask;
349	c_state = ad714x->c_state & mask;
350
351	switch (sw->state) {
352	case IDLE:
353		if (h_state) {
354			sw->state = JITTER;
355			/* In End of Conversion interrupt mode, the AD714X
356			 * continuously generates hardware interrupts.
357			 */
358			ad714x_slider_use_com_int(ad714x, idx);
359			dev_dbg(ad714x->dev, "slider %d touched\n", idx);
360		}
361		break;
362
363	case JITTER:
364		if (c_state == mask) {
365			ad714x_slider_cal_sensor_val(ad714x, idx);
366			ad714x_slider_cal_highest_stage(ad714x, idx);
367			ad714x_slider_cal_abs_pos(ad714x, idx);
368			sw->flt_pos = sw->abs_pos;
369			sw->state = ACTIVE;
370		}
371		break;
372
373	case ACTIVE:
374		if (c_state == mask) {
375			if (h_state) {
376				ad714x_slider_cal_sensor_val(ad714x, idx);
377				ad714x_slider_cal_highest_stage(ad714x, idx);
378				ad714x_slider_cal_abs_pos(ad714x, idx);
379				ad714x_slider_cal_flt_pos(ad714x, idx);
380				input_report_abs(sw->input, ABS_X, sw->flt_pos);
381				input_report_key(sw->input, BTN_TOUCH, 1);
382			} else {
383				/* When the user lifts off the sensor, configure
384				 * the AD714X back to threshold interrupt mode.
385				 */
386				ad714x_slider_use_thr_int(ad714x, idx);
387				sw->state = IDLE;
388				input_report_key(sw->input, BTN_TOUCH, 0);
389				dev_dbg(ad714x->dev, "slider %d released\n",
390					idx);
391			}
392			input_sync(sw->input);
393		}
394		break;
395
396	default:
397		break;
398	}
399}
400
401/*
402 * When the scroll wheel is activated, we compute the absolute position based
403 * on the sensor values. To calculate the position, we first determine the
404 * sensor that has the greatest response among the 8 sensors that constitutes
405 * the scrollwheel. Then we determined the 2 sensors on either sides of the
406 * sensor with the highest response and we apply weights to these sensors.
407 */
408static void ad714x_wheel_cal_highest_stage(struct ad714x_chip *ad714x, int idx)
409{
410	struct ad714x_wheel_plat *hw = &ad714x->hw->wheel[idx];
411	struct ad714x_wheel_drv *sw = &ad714x->sw->wheel[idx];
412
413	sw->pre_highest_stage = sw->highest_stage;
414	sw->highest_stage = ad714x_cal_highest_stage(ad714x, hw->start_stage,
415			hw->end_stage);
416
417	dev_dbg(ad714x->dev, "wheel %d highest_stage:%d\n", idx,
418		sw->highest_stage);
419}
420
421static void ad714x_wheel_cal_sensor_val(struct ad714x_chip *ad714x, int idx)
422{
423	struct ad714x_wheel_plat *hw = &ad714x->hw->wheel[idx];
424	int i;
425
426	ad714x->read(ad714x, CDC_RESULT_S0 + hw->start_stage,
427			&ad714x->adc_reg[hw->start_stage],
428			hw->end_stage - hw->start_stage + 1);
429
430	for (i = hw->start_stage; i <= hw->end_stage; i++) {
431		ad714x->read(ad714x, STAGE0_AMBIENT + i * PER_STAGE_REG_NUM,
432				&ad714x->amb_reg[i], 1);
433		if (ad714x->adc_reg[i] > ad714x->amb_reg[i])
434			ad714x->sensor_val[i] =
435				ad714x->adc_reg[i] - ad714x->amb_reg[i];
436		else
437			ad714x->sensor_val[i] = 0;
438	}
439}
440
441/*
442 * When the scroll wheel is activated, we compute the absolute position based
443 * on the sensor values. To calculate the position, we first determine the
444 * sensor that has the greatest response among the sensors that constitutes
445 * the scrollwheel. Then we determined the sensors on either sides of the
446 * sensor with the highest response and we apply weights to these sensors. The
447 * result of this computation gives us the mean value.
448 */
449
450static void ad714x_wheel_cal_abs_pos(struct ad714x_chip *ad714x, int idx)
451{
452	struct ad714x_wheel_plat *hw = &ad714x->hw->wheel[idx];
453	struct ad714x_wheel_drv *sw = &ad714x->sw->wheel[idx];
454	int stage_num = hw->end_stage - hw->start_stage + 1;
455	int first_before, highest, first_after;
456	int a_param, b_param;
457
458	first_before = (sw->highest_stage + stage_num - 1) % stage_num;
459	highest = sw->highest_stage;
460	first_after = (sw->highest_stage + stage_num + 1) % stage_num;
461
462	a_param = ad714x->sensor_val[highest] *
463		(highest - hw->start_stage) +
464		ad714x->sensor_val[first_before] *
465		(highest - hw->start_stage - 1) +
466		ad714x->sensor_val[first_after] *
467		(highest - hw->start_stage + 1);
468	b_param = ad714x->sensor_val[highest] +
469		ad714x->sensor_val[first_before] +
470		ad714x->sensor_val[first_after];
471
472	sw->abs_pos = ((hw->max_coord / (hw->end_stage - hw->start_stage)) *
473			a_param) / b_param;
474
475	if (sw->abs_pos > hw->max_coord)
476		sw->abs_pos = hw->max_coord;
477	else if (sw->abs_pos < 0)
478		sw->abs_pos = 0;
479}
480
481static void ad714x_wheel_cal_flt_pos(struct ad714x_chip *ad714x, int idx)
482{
483	struct ad714x_wheel_plat *hw = &ad714x->hw->wheel[idx];
484	struct ad714x_wheel_drv *sw = &ad714x->sw->wheel[idx];
485	if (((sw->pre_highest_stage == hw->end_stage) &&
486			(sw->highest_stage == hw->start_stage)) ||
487	    ((sw->pre_highest_stage == hw->start_stage) &&
488			(sw->highest_stage == hw->end_stage)))
489		sw->flt_pos = sw->abs_pos;
490	else
491		sw->flt_pos = ((sw->flt_pos * 30) + (sw->abs_pos * 71)) / 100;
492
493	if (sw->flt_pos > hw->max_coord)
494		sw->flt_pos = hw->max_coord;
495}
496
497static void ad714x_wheel_use_com_int(struct ad714x_chip *ad714x, int idx)
498{
499	struct ad714x_wheel_plat *hw = &ad714x->hw->wheel[idx];
500
501	ad714x_use_com_int(ad714x, hw->start_stage, hw->end_stage);
502}
503
504static void ad714x_wheel_use_thr_int(struct ad714x_chip *ad714x, int idx)
505{
506	struct ad714x_wheel_plat *hw = &ad714x->hw->wheel[idx];
507
508	ad714x_use_thr_int(ad714x, hw->start_stage, hw->end_stage);
509}
510
511static void ad714x_wheel_state_machine(struct ad714x_chip *ad714x, int idx)
512{
513	struct ad714x_wheel_plat *hw = &ad714x->hw->wheel[idx];
514	struct ad714x_wheel_drv *sw = &ad714x->sw->wheel[idx];
515	unsigned short h_state, c_state;
516	unsigned short mask;
517
518	mask = ((1 << (hw->end_stage + 1)) - 1) - ((1 << hw->start_stage) - 1);
519
520	h_state = ad714x->h_state & mask;
521	c_state = ad714x->c_state & mask;
522
523	switch (sw->state) {
524	case IDLE:
525		if (h_state) {
526			sw->state = JITTER;
527			/* In End of Conversion interrupt mode, the AD714X
528			 * continuously generates hardware interrupts.
529			 */
530			ad714x_wheel_use_com_int(ad714x, idx);
531			dev_dbg(ad714x->dev, "wheel %d touched\n", idx);
532		}
533		break;
534
535	case JITTER:
536		if (c_state == mask)	{
537			ad714x_wheel_cal_sensor_val(ad714x, idx);
538			ad714x_wheel_cal_highest_stage(ad714x, idx);
539			ad714x_wheel_cal_abs_pos(ad714x, idx);
540			sw->flt_pos = sw->abs_pos;
541			sw->state = ACTIVE;
542		}
543		break;
544
545	case ACTIVE:
546		if (c_state == mask) {
547			if (h_state) {
548				ad714x_wheel_cal_sensor_val(ad714x, idx);
549				ad714x_wheel_cal_highest_stage(ad714x, idx);
550				ad714x_wheel_cal_abs_pos(ad714x, idx);
551				ad714x_wheel_cal_flt_pos(ad714x, idx);
552				input_report_abs(sw->input, ABS_WHEEL,
553					sw->flt_pos);
554				input_report_key(sw->input, BTN_TOUCH, 1);
555			} else {
556				/* When the user lifts off the sensor, configure
557				 * the AD714X back to threshold interrupt mode.
558				 */
559				ad714x_wheel_use_thr_int(ad714x, idx);
560				sw->state = IDLE;
561				input_report_key(sw->input, BTN_TOUCH, 0);
562
563				dev_dbg(ad714x->dev, "wheel %d released\n",
564					idx);
565			}
566			input_sync(sw->input);
567		}
568		break;
569
570	default:
571		break;
572	}
573}
574
575static void touchpad_cal_sensor_val(struct ad714x_chip *ad714x, int idx)
576{
577	struct ad714x_touchpad_plat *hw = &ad714x->hw->touchpad[idx];
578	int i;
579
580	ad714x->read(ad714x, CDC_RESULT_S0 + hw->x_start_stage,
581			&ad714x->adc_reg[hw->x_start_stage],
582			hw->x_end_stage - hw->x_start_stage + 1);
583
584	for (i = hw->x_start_stage; i <= hw->x_end_stage; i++) {
585		ad714x->read(ad714x, STAGE0_AMBIENT + i * PER_STAGE_REG_NUM,
586				&ad714x->amb_reg[i], 1);
587		if (ad714x->adc_reg[i] > ad714x->amb_reg[i])
588			ad714x->sensor_val[i] =
589				ad714x->adc_reg[i] - ad714x->amb_reg[i];
590		else
591			ad714x->sensor_val[i] = 0;
592	}
593}
594
595static void touchpad_cal_highest_stage(struct ad714x_chip *ad714x, int idx)
596{
597	struct ad714x_touchpad_plat *hw = &ad714x->hw->touchpad[idx];
598	struct ad714x_touchpad_drv *sw = &ad714x->sw->touchpad[idx];
599
600	sw->x_highest_stage = ad714x_cal_highest_stage(ad714x,
601		hw->x_start_stage, hw->x_end_stage);
602	sw->y_highest_stage = ad714x_cal_highest_stage(ad714x,
603		hw->y_start_stage, hw->y_end_stage);
604
605	dev_dbg(ad714x->dev,
606		"touchpad %d x_highest_stage:%d, y_highest_stage:%d\n",
607		idx, sw->x_highest_stage, sw->y_highest_stage);
608}
609
610/*
611 * If 2 fingers are touching the sensor then 2 peaks can be observed in the
612 * distribution.
613 * The arithmetic doesn't support to get absolute coordinates for multi-touch
614 * yet.
615 */
616static int touchpad_check_second_peak(struct ad714x_chip *ad714x, int idx)
617{
618	struct ad714x_touchpad_plat *hw = &ad714x->hw->touchpad[idx];
619	struct ad714x_touchpad_drv *sw = &ad714x->sw->touchpad[idx];
620	int i;
621
622	for (i = hw->x_start_stage; i < sw->x_highest_stage; i++) {
623		if ((ad714x->sensor_val[i] - ad714x->sensor_val[i + 1])
624			> (ad714x->sensor_val[i + 1] / 10))
625			return 1;
626	}
627
628	for (i = sw->x_highest_stage; i < hw->x_end_stage; i++) {
629		if ((ad714x->sensor_val[i + 1] - ad714x->sensor_val[i])
630			> (ad714x->sensor_val[i] / 10))
631			return 1;
632	}
633
634	for (i = hw->y_start_stage; i < sw->y_highest_stage; i++) {
635		if ((ad714x->sensor_val[i] - ad714x->sensor_val[i + 1])
636			> (ad714x->sensor_val[i + 1] / 10))
637			return 1;
638	}
639
640	for (i = sw->y_highest_stage; i < hw->y_end_stage; i++) {
641		if ((ad714x->sensor_val[i + 1] - ad714x->sensor_val[i])
642			> (ad714x->sensor_val[i] / 10))
643			return 1;
644	}
645
646	return 0;
647}
648
649/*
650 * If only one finger is used to activate the touch pad then only 1 peak will be
651 * registered in the distribution. This peak and the 2 adjacent sensors will be
652 * used in the calculation of the absolute position. This will prevent hand
653 * shadows to affect the absolute position calculation.
654 */
655static void touchpad_cal_abs_pos(struct ad714x_chip *ad714x, int idx)
656{
657	struct ad714x_touchpad_plat *hw = &ad714x->hw->touchpad[idx];
658	struct ad714x_touchpad_drv *sw = &ad714x->sw->touchpad[idx];
659
660	sw->x_abs_pos = ad714x_cal_abs_pos(ad714x, hw->x_start_stage,
661			hw->x_end_stage, sw->x_highest_stage, hw->x_max_coord);
662	sw->y_abs_pos = ad714x_cal_abs_pos(ad714x, hw->y_start_stage,
663			hw->y_end_stage, sw->y_highest_stage, hw->y_max_coord);
664
665	dev_dbg(ad714x->dev, "touchpad %d absolute position:(%d, %d)\n", idx,
666			sw->x_abs_pos, sw->y_abs_pos);
667}
668
669static void touchpad_cal_flt_pos(struct ad714x_chip *ad714x, int idx)
670{
671	struct ad714x_touchpad_drv *sw = &ad714x->sw->touchpad[idx];
672
673	sw->x_flt_pos = (sw->x_flt_pos * (10 - 4) +
674			sw->x_abs_pos * 4)/10;
675	sw->y_flt_pos = (sw->y_flt_pos * (10 - 4) +
676			sw->y_abs_pos * 4)/10;
677
678	dev_dbg(ad714x->dev, "touchpad %d filter position:(%d, %d)\n",
679			idx, sw->x_flt_pos, sw->y_flt_pos);
680}
681
682/*
683 * To prevent distortion from showing in the absolute position, it is
684 * necessary to detect the end points. When endpoints are detected, the
685 * driver stops updating the status variables with absolute positions.
686 * End points are detected on the 4 edges of the touchpad sensor. The
687 * method to detect them is the same for all 4.
688 * To detect the end points, the firmware computes the difference in
689 * percent between the sensor on the edge and the adjacent one. The
690 * difference is calculated in percent in order to make the end point
691 * detection independent of the pressure.
692 */
693
694#define LEFT_END_POINT_DETECTION_LEVEL                  550
695#define RIGHT_END_POINT_DETECTION_LEVEL                 750
696#define LEFT_RIGHT_END_POINT_DEAVTIVALION_LEVEL         850
697#define TOP_END_POINT_DETECTION_LEVEL                   550
698#define BOTTOM_END_POINT_DETECTION_LEVEL                950
699#define TOP_BOTTOM_END_POINT_DEAVTIVALION_LEVEL         700
700static int touchpad_check_endpoint(struct ad714x_chip *ad714x, int idx)
701{
702	struct ad714x_touchpad_plat *hw = &ad714x->hw->touchpad[idx];
703	struct ad714x_touchpad_drv *sw  = &ad714x->sw->touchpad[idx];
704	int percent_sensor_diff;
705
706	/* left endpoint detect */
707	percent_sensor_diff = (ad714x->sensor_val[hw->x_start_stage] -
708			ad714x->sensor_val[hw->x_start_stage + 1]) * 100 /
709			ad714x->sensor_val[hw->x_start_stage + 1];
710	if (!sw->left_ep) {
711		if (percent_sensor_diff >= LEFT_END_POINT_DETECTION_LEVEL)  {
712			sw->left_ep = 1;
713			sw->left_ep_val =
714				ad714x->sensor_val[hw->x_start_stage + 1];
715		}
716	} else {
717		if ((percent_sensor_diff < LEFT_END_POINT_DETECTION_LEVEL) &&
718		    (ad714x->sensor_val[hw->x_start_stage + 1] >
719		     LEFT_RIGHT_END_POINT_DEAVTIVALION_LEVEL + sw->left_ep_val))
720			sw->left_ep = 0;
721	}
722
723	/* right endpoint detect */
724	percent_sensor_diff = (ad714x->sensor_val[hw->x_end_stage] -
725			ad714x->sensor_val[hw->x_end_stage - 1]) * 100 /
726			ad714x->sensor_val[hw->x_end_stage - 1];
727	if (!sw->right_ep) {
728		if (percent_sensor_diff >= RIGHT_END_POINT_DETECTION_LEVEL)  {
729			sw->right_ep = 1;
730			sw->right_ep_val =
731				ad714x->sensor_val[hw->x_end_stage - 1];
732		}
733	} else {
734		if ((percent_sensor_diff < RIGHT_END_POINT_DETECTION_LEVEL) &&
735		(ad714x->sensor_val[hw->x_end_stage - 1] >
736		LEFT_RIGHT_END_POINT_DEAVTIVALION_LEVEL + sw->right_ep_val))
737			sw->right_ep = 0;
738	}
739
740	/* top endpoint detect */
741	percent_sensor_diff = (ad714x->sensor_val[hw->y_start_stage] -
742			ad714x->sensor_val[hw->y_start_stage + 1]) * 100 /
743			ad714x->sensor_val[hw->y_start_stage + 1];
744	if (!sw->top_ep) {
745		if (percent_sensor_diff >= TOP_END_POINT_DETECTION_LEVEL)  {
746			sw->top_ep = 1;
747			sw->top_ep_val =
748				ad714x->sensor_val[hw->y_start_stage + 1];
749		}
750	} else {
751		if ((percent_sensor_diff < TOP_END_POINT_DETECTION_LEVEL) &&
752		(ad714x->sensor_val[hw->y_start_stage + 1] >
753		TOP_BOTTOM_END_POINT_DEAVTIVALION_LEVEL + sw->top_ep_val))
754			sw->top_ep = 0;
755	}
756
757	/* bottom endpoint detect */
758	percent_sensor_diff = (ad714x->sensor_val[hw->y_end_stage] -
759		ad714x->sensor_val[hw->y_end_stage - 1]) * 100 /
760		ad714x->sensor_val[hw->y_end_stage - 1];
761	if (!sw->bottom_ep) {
762		if (percent_sensor_diff >= BOTTOM_END_POINT_DETECTION_LEVEL)  {
763			sw->bottom_ep = 1;
764			sw->bottom_ep_val =
765				ad714x->sensor_val[hw->y_end_stage - 1];
766		}
767	} else {
768		if ((percent_sensor_diff < BOTTOM_END_POINT_DETECTION_LEVEL) &&
769		(ad714x->sensor_val[hw->y_end_stage - 1] >
770		 TOP_BOTTOM_END_POINT_DEAVTIVALION_LEVEL + sw->bottom_ep_val))
771			sw->bottom_ep = 0;
772	}
773
774	return sw->left_ep || sw->right_ep || sw->top_ep || sw->bottom_ep;
775}
776
777static void touchpad_use_com_int(struct ad714x_chip *ad714x, int idx)
778{
779	struct ad714x_touchpad_plat *hw = &ad714x->hw->touchpad[idx];
780
781	ad714x_use_com_int(ad714x, hw->x_start_stage, hw->x_end_stage);
782}
783
784static void touchpad_use_thr_int(struct ad714x_chip *ad714x, int idx)
785{
786	struct ad714x_touchpad_plat *hw = &ad714x->hw->touchpad[idx];
787
788	ad714x_use_thr_int(ad714x, hw->x_start_stage, hw->x_end_stage);
789	ad714x_use_thr_int(ad714x, hw->y_start_stage, hw->y_end_stage);
790}
791
792static void ad714x_touchpad_state_machine(struct ad714x_chip *ad714x, int idx)
793{
794	struct ad714x_touchpad_plat *hw = &ad714x->hw->touchpad[idx];
795	struct ad714x_touchpad_drv *sw = &ad714x->sw->touchpad[idx];
796	unsigned short h_state, c_state;
797	unsigned short mask;
798
799	mask = (((1 << (hw->x_end_stage + 1)) - 1) -
800		((1 << hw->x_start_stage) - 1)) +
801		(((1 << (hw->y_end_stage + 1)) - 1) -
802		((1 << hw->y_start_stage) - 1));
803
804	h_state = ad714x->h_state & mask;
805	c_state = ad714x->c_state & mask;
806
807	switch (sw->state) {
808	case IDLE:
809		if (h_state) {
810			sw->state = JITTER;
811			/* In End of Conversion interrupt mode, the AD714X
812			 * continuously generates hardware interrupts.
813			 */
814			touchpad_use_com_int(ad714x, idx);
815			dev_dbg(ad714x->dev, "touchpad %d touched\n", idx);
816		}
817		break;
818
819	case JITTER:
820		if (c_state == mask) {
821			touchpad_cal_sensor_val(ad714x, idx);
822			touchpad_cal_highest_stage(ad714x, idx);
823			if ((!touchpad_check_second_peak(ad714x, idx)) &&
824				(!touchpad_check_endpoint(ad714x, idx))) {
825				dev_dbg(ad714x->dev,
826					"touchpad%d, 2 fingers or endpoint\n",
827					idx);
828				touchpad_cal_abs_pos(ad714x, idx);
829				sw->x_flt_pos = sw->x_abs_pos;
830				sw->y_flt_pos = sw->y_abs_pos;
831				sw->state = ACTIVE;
832			}
833		}
834		break;
835
836	case ACTIVE:
837		if (c_state == mask) {
838			if (h_state) {
839				touchpad_cal_sensor_val(ad714x, idx);
840				touchpad_cal_highest_stage(ad714x, idx);
841				if ((!touchpad_check_second_peak(ad714x, idx))
842				  && (!touchpad_check_endpoint(ad714x, idx))) {
843					touchpad_cal_abs_pos(ad714x, idx);
844					touchpad_cal_flt_pos(ad714x, idx);
845					input_report_abs(sw->input, ABS_X,
846						sw->x_flt_pos);
847					input_report_abs(sw->input, ABS_Y,
848						sw->y_flt_pos);
849					input_report_key(sw->input, BTN_TOUCH,
850						1);
851				}
852			} else {
853				/* When the user lifts off the sensor, configure
854				 * the AD714X back to threshold interrupt mode.
855				 */
856				touchpad_use_thr_int(ad714x, idx);
857				sw->state = IDLE;
858				input_report_key(sw->input, BTN_TOUCH, 0);
859				dev_dbg(ad714x->dev, "touchpad %d released\n",
860					idx);
861			}
862			input_sync(sw->input);
863		}
864		break;
865
866	default:
867		break;
868	}
869}
870
871static int ad714x_hw_detect(struct ad714x_chip *ad714x)
872{
873	unsigned short data;
874
875	ad714x->read(ad714x, AD714X_PARTID_REG, &data, 1);
876	switch (data & 0xFFF0) {
877	case AD7142_PARTID:
878		ad714x->product = 0x7142;
879		ad714x->version = data & 0xF;
880		dev_info(ad714x->dev, "found AD7142 captouch, rev:%d\n",
881				ad714x->version);
882		return 0;
883
884	case AD7143_PARTID:
885		ad714x->product = 0x7143;
886		ad714x->version = data & 0xF;
887		dev_info(ad714x->dev, "found AD7143 captouch, rev:%d\n",
888				ad714x->version);
889		return 0;
890
891	case AD7147_PARTID:
892		ad714x->product = 0x7147;
893		ad714x->version = data & 0xF;
894		dev_info(ad714x->dev, "found AD7147(A) captouch, rev:%d\n",
895				ad714x->version);
896		return 0;
897
898	case AD7148_PARTID:
899		ad714x->product = 0x7148;
900		ad714x->version = data & 0xF;
901		dev_info(ad714x->dev, "found AD7148 captouch, rev:%d\n",
902				ad714x->version);
903		return 0;
904
905	default:
906		dev_err(ad714x->dev,
907			"fail to detect AD714X captouch, read ID is %04x\n",
908			data);
909		return -ENODEV;
910	}
911}
912
913static void ad714x_hw_init(struct ad714x_chip *ad714x)
914{
915	int i, j;
916	unsigned short reg_base;
917	unsigned short data;
918
919	/* configuration CDC and interrupts */
920
921	for (i = 0; i < STAGE_NUM; i++) {
922		reg_base = AD714X_STAGECFG_REG + i * STAGE_CFGREG_NUM;
923		for (j = 0; j < STAGE_CFGREG_NUM; j++)
924			ad714x->write(ad714x, reg_base + j,
925					ad714x->hw->stage_cfg_reg[i][j]);
926	}
927
928	for (i = 0; i < SYS_CFGREG_NUM; i++)
929		ad714x->write(ad714x, AD714X_SYSCFG_REG + i,
930			ad714x->hw->sys_cfg_reg[i]);
931	for (i = 0; i < SYS_CFGREG_NUM; i++)
932		ad714x->read(ad714x, AD714X_SYSCFG_REG + i, &data, 1);
933
934	ad714x->write(ad714x, AD714X_STG_CAL_EN_REG, 0xFFF);
935
936	/* clear all interrupts */
937	ad714x->read(ad714x, STG_LOW_INT_STA_REG, &ad714x->l_state, 3);
938}
939
940static irqreturn_t ad714x_interrupt_thread(int irq, void *data)
941{
942	struct ad714x_chip *ad714x = data;
943	int i;
944
945	mutex_lock(&ad714x->mutex);
946
947	ad714x->read(ad714x, STG_LOW_INT_STA_REG, &ad714x->l_state, 3);
948
949	for (i = 0; i < ad714x->hw->button_num; i++)
950		ad714x_button_state_machine(ad714x, i);
951	for (i = 0; i < ad714x->hw->slider_num; i++)
952		ad714x_slider_state_machine(ad714x, i);
953	for (i = 0; i < ad714x->hw->wheel_num; i++)
954		ad714x_wheel_state_machine(ad714x, i);
955	for (i = 0; i < ad714x->hw->touchpad_num; i++)
956		ad714x_touchpad_state_machine(ad714x, i);
957
958	mutex_unlock(&ad714x->mutex);
959
960	return IRQ_HANDLED;
961}
962
963#define MAX_DEVICE_NUM 8
964struct ad714x_chip *ad714x_probe(struct device *dev, u16 bus_type, int irq,
965				 ad714x_read_t read, ad714x_write_t write)
966{
967	int i, alloc_idx;
968	int error;
969	struct input_dev *input[MAX_DEVICE_NUM];
970
971	struct ad714x_platform_data *plat_data = dev_get_platdata(dev);
972	struct ad714x_chip *ad714x;
973	void *drv_mem;
974	unsigned long irqflags;
975
976	struct ad714x_button_drv *bt_drv;
977	struct ad714x_slider_drv *sd_drv;
978	struct ad714x_wheel_drv *wl_drv;
979	struct ad714x_touchpad_drv *tp_drv;
980
981
982	if (irq <= 0) {
983		dev_err(dev, "IRQ not configured!\n");
984		error = -EINVAL;
985		goto err_out;
986	}
987
988	if (dev_get_platdata(dev) == NULL) {
989		dev_err(dev, "platform data for ad714x doesn't exist\n");
990		error = -EINVAL;
991		goto err_out;
992	}
993
994	ad714x = kzalloc(sizeof(*ad714x) + sizeof(*ad714x->sw) +
995			 sizeof(*sd_drv) * plat_data->slider_num +
996			 sizeof(*wl_drv) * plat_data->wheel_num +
997			 sizeof(*tp_drv) * plat_data->touchpad_num +
998			 sizeof(*bt_drv) * plat_data->button_num, GFP_KERNEL);
999	if (!ad714x) {
1000		error = -ENOMEM;
1001		goto err_out;
1002	}
1003
1004	ad714x->hw = plat_data;
1005
1006	drv_mem = ad714x + 1;
1007	ad714x->sw = drv_mem;
1008	drv_mem += sizeof(*ad714x->sw);
1009	ad714x->sw->slider = sd_drv = drv_mem;
1010	drv_mem += sizeof(*sd_drv) * ad714x->hw->slider_num;
1011	ad714x->sw->wheel = wl_drv = drv_mem;
1012	drv_mem += sizeof(*wl_drv) * ad714x->hw->wheel_num;
1013	ad714x->sw->touchpad = tp_drv = drv_mem;
1014	drv_mem += sizeof(*tp_drv) * ad714x->hw->touchpad_num;
1015	ad714x->sw->button = bt_drv = drv_mem;
1016	drv_mem += sizeof(*bt_drv) * ad714x->hw->button_num;
1017
1018	ad714x->read = read;
1019	ad714x->write = write;
1020	ad714x->irq = irq;
1021	ad714x->dev = dev;
1022
1023	error = ad714x_hw_detect(ad714x);
1024	if (error)
1025		goto err_free_mem;
1026
1027	/* initialize and request sw/hw resources */
1028
1029	ad714x_hw_init(ad714x);
1030	mutex_init(&ad714x->mutex);
1031
1032	/*
1033	 * Allocate and register AD714X input device
1034	 */
1035	alloc_idx = 0;
1036
1037	/* a slider uses one input_dev instance */
1038	if (ad714x->hw->slider_num > 0) {
1039		struct ad714x_slider_plat *sd_plat = ad714x->hw->slider;
1040
1041		for (i = 0; i < ad714x->hw->slider_num; i++) {
1042			sd_drv[i].input = input[alloc_idx] = input_allocate_device();
1043			if (!input[alloc_idx]) {
1044				error = -ENOMEM;
1045				goto err_free_dev;
1046			}
1047
1048			__set_bit(EV_ABS, input[alloc_idx]->evbit);
1049			__set_bit(EV_KEY, input[alloc_idx]->evbit);
1050			__set_bit(ABS_X, input[alloc_idx]->absbit);
1051			__set_bit(BTN_TOUCH, input[alloc_idx]->keybit);
1052			input_set_abs_params(input[alloc_idx],
1053				ABS_X, 0, sd_plat->max_coord, 0, 0);
1054
1055			input[alloc_idx]->id.bustype = bus_type;
1056			input[alloc_idx]->id.product = ad714x->product;
1057			input[alloc_idx]->id.version = ad714x->version;
1058			input[alloc_idx]->name = "ad714x_captouch_slider";
1059			input[alloc_idx]->dev.parent = dev;
1060
1061			error = input_register_device(input[alloc_idx]);
1062			if (error)
1063				goto err_free_dev;
1064
1065			alloc_idx++;
1066		}
1067	}
1068
1069	/* a wheel uses one input_dev instance */
1070	if (ad714x->hw->wheel_num > 0) {
1071		struct ad714x_wheel_plat *wl_plat = ad714x->hw->wheel;
1072
1073		for (i = 0; i < ad714x->hw->wheel_num; i++) {
1074			wl_drv[i].input = input[alloc_idx] = input_allocate_device();
1075			if (!input[alloc_idx]) {
1076				error = -ENOMEM;
1077				goto err_free_dev;
1078			}
1079
1080			__set_bit(EV_KEY, input[alloc_idx]->evbit);
1081			__set_bit(EV_ABS, input[alloc_idx]->evbit);
1082			__set_bit(ABS_WHEEL, input[alloc_idx]->absbit);
1083			__set_bit(BTN_TOUCH, input[alloc_idx]->keybit);
1084			input_set_abs_params(input[alloc_idx],
1085				ABS_WHEEL, 0, wl_plat->max_coord, 0, 0);
1086
1087			input[alloc_idx]->id.bustype = bus_type;
1088			input[alloc_idx]->id.product = ad714x->product;
1089			input[alloc_idx]->id.version = ad714x->version;
1090			input[alloc_idx]->name = "ad714x_captouch_wheel";
1091			input[alloc_idx]->dev.parent = dev;
1092
1093			error = input_register_device(input[alloc_idx]);
1094			if (error)
1095				goto err_free_dev;
1096
1097			alloc_idx++;
1098		}
1099	}
1100
1101	/* a touchpad uses one input_dev instance */
1102	if (ad714x->hw->touchpad_num > 0) {
1103		struct ad714x_touchpad_plat *tp_plat = ad714x->hw->touchpad;
1104
1105		for (i = 0; i < ad714x->hw->touchpad_num; i++) {
1106			tp_drv[i].input = input[alloc_idx] = input_allocate_device();
1107			if (!input[alloc_idx]) {
1108				error = -ENOMEM;
1109				goto err_free_dev;
1110			}
1111
1112			__set_bit(EV_ABS, input[alloc_idx]->evbit);
1113			__set_bit(EV_KEY, input[alloc_idx]->evbit);
1114			__set_bit(ABS_X, input[alloc_idx]->absbit);
1115			__set_bit(ABS_Y, input[alloc_idx]->absbit);
1116			__set_bit(BTN_TOUCH, input[alloc_idx]->keybit);
1117			input_set_abs_params(input[alloc_idx],
1118				ABS_X, 0, tp_plat->x_max_coord, 0, 0);
1119			input_set_abs_params(input[alloc_idx],
1120				ABS_Y, 0, tp_plat->y_max_coord, 0, 0);
1121
1122			input[alloc_idx]->id.bustype = bus_type;
1123			input[alloc_idx]->id.product = ad714x->product;
1124			input[alloc_idx]->id.version = ad714x->version;
1125			input[alloc_idx]->name = "ad714x_captouch_pad";
1126			input[alloc_idx]->dev.parent = dev;
1127
1128			error = input_register_device(input[alloc_idx]);
1129			if (error)
1130				goto err_free_dev;
1131
1132			alloc_idx++;
1133		}
1134	}
1135
1136	/* all buttons use one input node */
1137	if (ad714x->hw->button_num > 0) {
1138		struct ad714x_button_plat *bt_plat = ad714x->hw->button;
1139
1140		input[alloc_idx] = input_allocate_device();
1141		if (!input[alloc_idx]) {
1142			error = -ENOMEM;
1143			goto err_free_dev;
1144		}
1145
1146		__set_bit(EV_KEY, input[alloc_idx]->evbit);
1147		for (i = 0; i < ad714x->hw->button_num; i++) {
1148			bt_drv[i].input = input[alloc_idx];
1149			__set_bit(bt_plat[i].keycode, input[alloc_idx]->keybit);
1150		}
1151
1152		input[alloc_idx]->id.bustype = bus_type;
1153		input[alloc_idx]->id.product = ad714x->product;
1154		input[alloc_idx]->id.version = ad714x->version;
1155		input[alloc_idx]->name = "ad714x_captouch_button";
1156		input[alloc_idx]->dev.parent = dev;
1157
1158		error = input_register_device(input[alloc_idx]);
1159		if (error)
1160			goto err_free_dev;
1161
1162		alloc_idx++;
1163	}
1164
1165	irqflags = plat_data->irqflags ?: IRQF_TRIGGER_FALLING;
1166	irqflags |= IRQF_ONESHOT;
1167
1168	error = request_threaded_irq(ad714x->irq, NULL, ad714x_interrupt_thread,
1169				     irqflags, "ad714x_captouch", ad714x);
1170	if (error) {
1171		dev_err(dev, "can't allocate irq %d\n", ad714x->irq);
1172		goto err_unreg_dev;
1173	}
1174
1175	return ad714x;
1176
1177 err_free_dev:
1178	dev_err(dev, "failed to setup AD714x input device %i\n", alloc_idx);
1179	input_free_device(input[alloc_idx]);
1180 err_unreg_dev:
1181	while (--alloc_idx >= 0)
1182		input_unregister_device(input[alloc_idx]);
1183 err_free_mem:
1184	kfree(ad714x);
1185 err_out:
1186	return ERR_PTR(error);
1187}
1188EXPORT_SYMBOL(ad714x_probe);
1189
1190void ad714x_remove(struct ad714x_chip *ad714x)
1191{
1192	struct ad714x_platform_data *hw = ad714x->hw;
1193	struct ad714x_driver_data *sw = ad714x->sw;
1194	int i;
1195
1196	free_irq(ad714x->irq, ad714x);
1197
1198	/* unregister and free all input devices */
1199
1200	for (i = 0; i < hw->slider_num; i++)
1201		input_unregister_device(sw->slider[i].input);
1202
1203	for (i = 0; i < hw->wheel_num; i++)
1204		input_unregister_device(sw->wheel[i].input);
1205
1206	for (i = 0; i < hw->touchpad_num; i++)
1207		input_unregister_device(sw->touchpad[i].input);
1208
1209	if (hw->button_num)
1210		input_unregister_device(sw->button[0].input);
1211
1212	kfree(ad714x);
1213}
1214EXPORT_SYMBOL(ad714x_remove);
1215
1216#ifdef CONFIG_PM
1217int ad714x_disable(struct ad714x_chip *ad714x)
1218{
1219	unsigned short data;
1220
1221	dev_dbg(ad714x->dev, "%s enter\n", __func__);
1222
1223	mutex_lock(&ad714x->mutex);
1224
1225	data = ad714x->hw->sys_cfg_reg[AD714X_PWR_CTRL] | 0x3;
1226	ad714x->write(ad714x, AD714X_PWR_CTRL, data);
1227
1228	mutex_unlock(&ad714x->mutex);
1229
1230	return 0;
1231}
1232EXPORT_SYMBOL(ad714x_disable);
1233
1234int ad714x_enable(struct ad714x_chip *ad714x)
1235{
1236	dev_dbg(ad714x->dev, "%s enter\n", __func__);
1237
1238	mutex_lock(&ad714x->mutex);
1239
1240	/* resume to non-shutdown mode */
1241
1242	ad714x->write(ad714x, AD714X_PWR_CTRL,
1243			ad714x->hw->sys_cfg_reg[AD714X_PWR_CTRL]);
1244
1245	/* make sure the interrupt output line is not low level after resume,
1246	 * otherwise we will get no chance to enter falling-edge irq again
1247	 */
1248
1249	ad714x->read(ad714x, STG_LOW_INT_STA_REG, &ad714x->l_state, 3);
1250
1251	mutex_unlock(&ad714x->mutex);
1252
1253	return 0;
1254}
1255EXPORT_SYMBOL(ad714x_enable);
1256#endif
1257
1258MODULE_DESCRIPTION("Analog Devices AD714X Capacitance Touch Sensor Driver");
1259MODULE_AUTHOR("Barry Song <21cnbao@gmail.com>");
1260MODULE_LICENSE("GPL");
1261