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_US	3000
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 */
188static bool no_decel = true;
189module_param(no_decel, bool, 0644);
190MODULE_PARM_DESC(no_decel, "No Deceleration. Default = 1 (on)");
191
192/* Control touchpad's Reduced Reporting option */
193static bool reduce_report;
194module_param(reduce_report, bool, 0644);
195MODULE_PARM_DESC(reduce_report, "Reduced Reporting. Default = 0 (off)");
196
197/* Control touchpad's No Filter option */
198static bool no_filter;
199module_param(no_filter, bool, 0644);
200MODULE_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 */
208static bool polling_req;
209module_param(polling_req, bool, 0444);
210MODULE_PARM_DESC(polling_req, "Request Polling. Default = 0 (use irq)");
211
212/* Control Polling Rate */
213static int scan_rate = 80;
214module_param(scan_rate, int, 0644);
215MODULE_PARM_DESC(scan_rate, "Polling rate in times/sec. Default = 80");
216
217/* The main device structure */
218struct synaptics_i2c {
219	struct i2c_client	*client;
220	struct input_dev	*input;
221	struct delayed_work	dwork;
222	int			no_data_count;
223	int			no_decel_param;
224	int			reduce_report_param;
225	int			no_filter_param;
226	int			scan_rate_param;
227	int			scan_ms;
228};
229
230static inline void set_scan_rate(struct synaptics_i2c *touch, int scan_rate)
231{
232	touch->scan_ms = MSEC_PER_SEC / scan_rate;
233	touch->scan_rate_param = scan_rate;
234}
235
236/*
237 * Driver's initial design makes no race condition possible on i2c bus,
238 * so there is no need in any locking.
239 * Keep it in mind, while playing with the code.
240 */
241static s32 synaptics_i2c_reg_get(struct i2c_client *client, u16 reg)
242{
243	int ret;
244
245	ret = i2c_smbus_write_byte_data(client, PAGE_SEL_REG, reg >> 8);
246	if (ret == 0)
247		ret = i2c_smbus_read_byte_data(client, reg & 0xff);
248
249	return ret;
250}
251
252static s32 synaptics_i2c_reg_set(struct i2c_client *client, u16 reg, u8 val)
253{
254	int ret;
255
256	ret = i2c_smbus_write_byte_data(client, PAGE_SEL_REG, reg >> 8);
257	if (ret == 0)
258		ret = i2c_smbus_write_byte_data(client, reg & 0xff, val);
259
260	return ret;
261}
262
263static s32 synaptics_i2c_word_get(struct i2c_client *client, u16 reg)
264{
265	int ret;
266
267	ret = i2c_smbus_write_byte_data(client, PAGE_SEL_REG, reg >> 8);
268	if (ret == 0)
269		ret = i2c_smbus_read_word_data(client, reg & 0xff);
270
271	return ret;
272}
273
274static int synaptics_i2c_config(struct i2c_client *client)
275{
276	int ret, control;
277	u8 int_en;
278
279	/* set Report Rate to Device Highest (>=80) and Sleep to normal */
280	ret = synaptics_i2c_reg_set(client, DEV_CONTROL_REG, 0xc1);
281	if (ret)
282		return ret;
283
284	/* set Interrupt Disable to Func20 / Enable to Func10) */
285	int_en = (polling_req) ? 0 : INT_ENA_ABS_MSK | INT_ENA_REL_MSK;
286	ret = synaptics_i2c_reg_set(client, INTERRUPT_EN_REG, int_en);
287	if (ret)
288		return ret;
289
290	control = synaptics_i2c_reg_get(client, GENERAL_2D_CONTROL_REG);
291	/* No Deceleration */
292	control |= no_decel ? 1 << NO_DECELERATION : 0;
293	/* Reduced Reporting */
294	control |= reduce_report ? 1 << REDUCE_REPORTING : 0;
295	/* No Filter */
296	control |= no_filter ? 1 << NO_FILTER : 0;
297	ret = synaptics_i2c_reg_set(client, GENERAL_2D_CONTROL_REG, control);
298	if (ret)
299		return ret;
300
301	return 0;
302}
303
304static int synaptics_i2c_reset_config(struct i2c_client *client)
305{
306	int ret;
307
308	/* Reset the Touchpad */
309	ret = synaptics_i2c_reg_set(client, DEV_COMMAND_REG, RESET_COMMAND);
310	if (ret) {
311		dev_err(&client->dev, "Unable to reset device\n");
312	} else {
313		usleep_range(SOFT_RESET_DELAY_US, SOFT_RESET_DELAY_US + 100);
314		ret = synaptics_i2c_config(client);
315		if (ret)
316			dev_err(&client->dev, "Unable to config device\n");
317	}
318
319	return ret;
320}
321
322static int synaptics_i2c_check_error(struct i2c_client *client)
323{
324	int status, ret = 0;
325
326	status = i2c_smbus_read_byte_data(client, DEVICE_STATUS_REG) &
327		(CONFIGURED_MSK | ERROR_MSK);
328
329	if (status != CONFIGURED_MSK)
330		ret = synaptics_i2c_reset_config(client);
331
332	return ret;
333}
334
335static bool synaptics_i2c_get_input(struct synaptics_i2c *touch)
336{
337	struct input_dev *input = touch->input;
338	int xy_delta, gesture;
339	s32 data;
340	s8 x_delta, y_delta;
341
342	/* Deal with spontaneous resets and errors */
343	if (synaptics_i2c_check_error(touch->client))
344		return false;
345
346	/* Get Gesture Bit */
347	data = synaptics_i2c_reg_get(touch->client, DATA_REG0);
348	gesture = (data >> GESTURE) & 0x1;
349
350	/*
351	 * Get Relative axes. we have to get them in one shot,
352	 * so we get 2 bytes starting from REL_X_REG.
353	 */
354	xy_delta = synaptics_i2c_word_get(touch->client, REL_X_REG) & 0xffff;
355
356	/* Separate X from Y */
357	x_delta = xy_delta & 0xff;
358	y_delta = (xy_delta >> REGISTER_LENGTH) & 0xff;
359
360	/* Report the button event */
361	input_report_key(input, BTN_LEFT, gesture);
362
363	/* Report the deltas */
364	input_report_rel(input, REL_X, x_delta);
365	input_report_rel(input, REL_Y, -y_delta);
366	input_sync(input);
367
368	return xy_delta || gesture;
369}
370
371static irqreturn_t synaptics_i2c_irq(int irq, void *dev_id)
372{
373	struct synaptics_i2c *touch = dev_id;
374
375	mod_delayed_work(system_wq, &touch->dwork, 0);
376
377	return IRQ_HANDLED;
378}
379
380static void synaptics_i2c_check_params(struct synaptics_i2c *touch)
381{
382	bool reset = false;
383
384	if (scan_rate != touch->scan_rate_param)
385		set_scan_rate(touch, scan_rate);
386
387	if (no_decel != touch->no_decel_param) {
388		touch->no_decel_param = no_decel;
389		reset = true;
390	}
391
392	if (no_filter != touch->no_filter_param) {
393		touch->no_filter_param = no_filter;
394		reset = true;
395	}
396
397	if (reduce_report != touch->reduce_report_param) {
398		touch->reduce_report_param = reduce_report;
399		reset = true;
400	}
401
402	if (reset)
403		synaptics_i2c_reset_config(touch->client);
404}
405
406/* Control the Device polling rate / Work Handler sleep time */
407static unsigned long synaptics_i2c_adjust_delay(struct synaptics_i2c *touch,
408						bool have_data)
409{
410	unsigned long delay, nodata_count_thres;
411
412	if (polling_req) {
413		delay = touch->scan_ms;
414		if (have_data) {
415			touch->no_data_count = 0;
416		} else {
417			nodata_count_thres = NO_DATA_THRES / touch->scan_ms;
418			if (touch->no_data_count < nodata_count_thres)
419				touch->no_data_count++;
420			else
421				delay = NO_DATA_SLEEP_MSECS;
422		}
423		return msecs_to_jiffies(delay);
424	} else {
425		delay = msecs_to_jiffies(THREAD_IRQ_SLEEP_MSECS);
426		return round_jiffies_relative(delay);
427	}
428}
429
430/* Work Handler */
431static void synaptics_i2c_work_handler(struct work_struct *work)
432{
433	bool have_data;
434	struct synaptics_i2c *touch =
435			container_of(work, struct synaptics_i2c, dwork.work);
436	unsigned long delay;
437
438	synaptics_i2c_check_params(touch);
439
440	have_data = synaptics_i2c_get_input(touch);
441	delay = synaptics_i2c_adjust_delay(touch, have_data);
442
443	/*
444	 * While interrupt driven, there is no real need to poll the device.
445	 * But touchpads are very sensitive, so there could be errors
446	 * related to physical environment and the attention line isn't
447	 * necessarily asserted. In such case we can lose the touchpad.
448	 * We poll the device once in THREAD_IRQ_SLEEP_SECS and
449	 * if error is detected, we try to reset and reconfigure the touchpad.
450	 */
451	mod_delayed_work(system_wq, &touch->dwork, delay);
452}
453
454static int synaptics_i2c_open(struct input_dev *input)
455{
456	struct synaptics_i2c *touch = input_get_drvdata(input);
457	int ret;
458
459	ret = synaptics_i2c_reset_config(touch->client);
460	if (ret)
461		return ret;
462
463	if (polling_req)
464		mod_delayed_work(system_wq, &touch->dwork,
465				msecs_to_jiffies(NO_DATA_SLEEP_MSECS));
466
467	return 0;
468}
469
470static void synaptics_i2c_close(struct input_dev *input)
471{
472	struct synaptics_i2c *touch = input_get_drvdata(input);
473
474	if (!polling_req)
475		synaptics_i2c_reg_set(touch->client, INTERRUPT_EN_REG, 0);
476
477	cancel_delayed_work_sync(&touch->dwork);
478
479	/* Save some power */
480	synaptics_i2c_reg_set(touch->client, DEV_CONTROL_REG, DEEP_SLEEP);
481}
482
483static void synaptics_i2c_set_input_params(struct synaptics_i2c *touch)
484{
485	struct input_dev *input = touch->input;
486
487	input->name = touch->client->name;
488	input->phys = touch->client->adapter->name;
489	input->id.bustype = BUS_I2C;
490	input->id.version = synaptics_i2c_word_get(touch->client,
491						   INFO_QUERY_REG0);
492	input->dev.parent = &touch->client->dev;
493	input->open = synaptics_i2c_open;
494	input->close = synaptics_i2c_close;
495	input_set_drvdata(input, touch);
496
497	/* Register the device as mouse */
498	__set_bit(EV_REL, input->evbit);
499	__set_bit(REL_X, input->relbit);
500	__set_bit(REL_Y, input->relbit);
501
502	/* Register device's buttons and keys */
503	__set_bit(EV_KEY, input->evbit);
504	__set_bit(BTN_LEFT, input->keybit);
505}
506
507static struct synaptics_i2c *synaptics_i2c_touch_create(struct i2c_client *client)
508{
509	struct synaptics_i2c *touch;
510
511	touch = kzalloc(sizeof(struct synaptics_i2c), GFP_KERNEL);
512	if (!touch)
513		return NULL;
514
515	touch->client = client;
516	touch->no_decel_param = no_decel;
517	touch->scan_rate_param = scan_rate;
518	set_scan_rate(touch, scan_rate);
519	INIT_DELAYED_WORK(&touch->dwork, synaptics_i2c_work_handler);
520
521	return touch;
522}
523
524static int synaptics_i2c_probe(struct i2c_client *client)
525{
526	int ret;
527	struct synaptics_i2c *touch;
528
529	touch = synaptics_i2c_touch_create(client);
530	if (!touch)
531		return -ENOMEM;
532
533	ret = synaptics_i2c_reset_config(client);
534	if (ret)
535		goto err_mem_free;
536
537	if (client->irq < 1)
538		polling_req = true;
539
540	touch->input = input_allocate_device();
541	if (!touch->input) {
542		ret = -ENOMEM;
543		goto err_mem_free;
544	}
545
546	synaptics_i2c_set_input_params(touch);
547
548	if (!polling_req) {
549		dev_dbg(&touch->client->dev,
550			 "Requesting IRQ: %d\n", touch->client->irq);
551
552		ret = request_irq(touch->client->irq, synaptics_i2c_irq,
553				  IRQ_TYPE_EDGE_FALLING,
554				  DRIVER_NAME, touch);
555		if (ret) {
556			dev_warn(&touch->client->dev,
557				  "IRQ request failed: %d, "
558				  "falling back to polling\n", ret);
559			polling_req = true;
560			synaptics_i2c_reg_set(touch->client,
561					      INTERRUPT_EN_REG, 0);
562		}
563	}
564
565	if (polling_req)
566		dev_dbg(&touch->client->dev,
567			 "Using polling at rate: %d times/sec\n", scan_rate);
568
569	/* Register the device in input subsystem */
570	ret = input_register_device(touch->input);
571	if (ret) {
572		dev_err(&client->dev,
573			 "Input device register failed: %d\n", ret);
574		goto err_input_free;
575	}
576
577	i2c_set_clientdata(client, touch);
578
579	return 0;
580
581err_input_free:
582	input_free_device(touch->input);
583err_mem_free:
584	kfree(touch);
585
586	return ret;
587}
588
589static void synaptics_i2c_remove(struct i2c_client *client)
590{
591	struct synaptics_i2c *touch = i2c_get_clientdata(client);
592
593	if (!polling_req)
594		free_irq(client->irq, touch);
595
596	input_unregister_device(touch->input);
597	kfree(touch);
598}
599
600static int synaptics_i2c_suspend(struct device *dev)
601{
602	struct i2c_client *client = to_i2c_client(dev);
603	struct synaptics_i2c *touch = i2c_get_clientdata(client);
604
605	cancel_delayed_work_sync(&touch->dwork);
606
607	/* Save some power */
608	synaptics_i2c_reg_set(touch->client, DEV_CONTROL_REG, DEEP_SLEEP);
609
610	return 0;
611}
612
613static int synaptics_i2c_resume(struct device *dev)
614{
615	int ret;
616	struct i2c_client *client = to_i2c_client(dev);
617	struct synaptics_i2c *touch = i2c_get_clientdata(client);
618
619	ret = synaptics_i2c_reset_config(client);
620	if (ret)
621		return ret;
622
623	mod_delayed_work(system_wq, &touch->dwork,
624				msecs_to_jiffies(NO_DATA_SLEEP_MSECS));
625
626	return 0;
627}
628
629static DEFINE_SIMPLE_DEV_PM_OPS(synaptics_i2c_pm, synaptics_i2c_suspend,
630				synaptics_i2c_resume);
631
632static const struct i2c_device_id synaptics_i2c_id_table[] = {
633	{ "synaptics_i2c", 0 },
634	{ },
635};
636MODULE_DEVICE_TABLE(i2c, synaptics_i2c_id_table);
637
638#ifdef CONFIG_OF
639static const struct of_device_id synaptics_i2c_of_match[] = {
640	{ .compatible = "synaptics,synaptics_i2c", },
641	{ },
642};
643MODULE_DEVICE_TABLE(of, synaptics_i2c_of_match);
644#endif
645
646static struct i2c_driver synaptics_i2c_driver = {
647	.driver = {
648		.name	= DRIVER_NAME,
649		.of_match_table = of_match_ptr(synaptics_i2c_of_match),
650		.pm	= pm_sleep_ptr(&synaptics_i2c_pm),
651	},
652
653	.probe		= synaptics_i2c_probe,
654	.remove		= synaptics_i2c_remove,
655
656	.id_table	= synaptics_i2c_id_table,
657};
658
659module_i2c_driver(synaptics_i2c_driver);
660
661MODULE_DESCRIPTION("Synaptics I2C touchpad driver");
662MODULE_AUTHOR("Mike Rapoport, Igor Grinberg, Compulab");
663MODULE_LICENSE("GPL");
664
665