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1/*
2 * Synaptics touchpad with I2C interface
3 *
4 * Copyright (C) 2009 Compulab, Ltd.
5 * Mike Rapoport <[email protected]>
6 * Igor Grinberg <[email protected]>
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 error;
244
245 error = i2c_smbus_write_byte_data(client, PAGE_SEL_REG, reg >> 8);
246 if (error)
247 return error;
248
249 return i2c_smbus_read_byte_data(client, reg & 0xff);
250}
251
252static s32 synaptics_i2c_reg_set(struct i2c_client *client, u16 reg, u8 val)
253{
254 int error;
255
256 error = i2c_smbus_write_byte_data(client, PAGE_SEL_REG, reg >> 8);
257 if (error)
258 return error;
259
260 error = i2c_smbus_write_byte_data(client, reg & 0xff, val);
261 if (error)
262 return error;
263
264 return 0;
265}
266
267static s32 synaptics_i2c_word_get(struct i2c_client *client, u16 reg)
268{
269 int error;
270
271 error = i2c_smbus_write_byte_data(client, PAGE_SEL_REG, reg >> 8);
272 if (error)
273 return error;
274
275 return i2c_smbus_read_word_data(client, reg & 0xff);
276}
277
278static int synaptics_i2c_config(struct i2c_client *client)
279{
280 int control;
281 int error;
282 u8 int_en;
283
284 /* set Report Rate to Device Highest (>=80) and Sleep to normal */
285 error = synaptics_i2c_reg_set(client, DEV_CONTROL_REG, 0xc1);
286 if (error)
287 return error;
288
289 /* set Interrupt Disable to Func20 / Enable to Func10) */
290 int_en = (polling_req) ? 0 : INT_ENA_ABS_MSK | INT_ENA_REL_MSK;
291 error = synaptics_i2c_reg_set(client, INTERRUPT_EN_REG, int_en);
292 if (error)
293 return error;
294
295 control = synaptics_i2c_reg_get(client, GENERAL_2D_CONTROL_REG);
296 /* No Deceleration */
297 control |= no_decel ? 1 << NO_DECELERATION : 0;
298 /* Reduced Reporting */
299 control |= reduce_report ? 1 << REDUCE_REPORTING : 0;
300 /* No Filter */
301 control |= no_filter ? 1 << NO_FILTER : 0;
302 error = synaptics_i2c_reg_set(client, GENERAL_2D_CONTROL_REG, control);
303 if (error)
304 return error;
305
306 return 0;
307}
308
309static int synaptics_i2c_reset_config(struct i2c_client *client)
310{
311 int error;
312
313 /* Reset the Touchpad */
314 error = synaptics_i2c_reg_set(client, DEV_COMMAND_REG, RESET_COMMAND);
315 if (error) {
316 dev_err(&client->dev, "Unable to reset device\n");
317 return error;
318 }
319
320 usleep_range(SOFT_RESET_DELAY_US, SOFT_RESET_DELAY_US + 100);
321 error = synaptics_i2c_config(client);
322 if (error) {
323 dev_err(&client->dev, "Unable to config device\n");
324 return error;
325 }
326
327 return 0;
328}
329
330static int synaptics_i2c_check_error(struct i2c_client *client)
331{
332 int status;
333 int error;
334
335 status = i2c_smbus_read_byte_data(client, DEVICE_STATUS_REG) &
336 (CONFIGURED_MSK | ERROR_MSK);
337
338 if (status != CONFIGURED_MSK) {
339 error = synaptics_i2c_reset_config(client);
340 if (error)
341 return error;
342 }
343
344 return 0;
345}
346
347static bool synaptics_i2c_get_input(struct synaptics_i2c *touch)
348{
349 struct input_dev *input = touch->input;
350 int xy_delta, gesture;
351 s32 data;
352 s8 x_delta, y_delta;
353
354 /* Deal with spontaneous resets and errors */
355 if (synaptics_i2c_check_error(touch->client))
356 return false;
357
358 /* Get Gesture Bit */
359 data = synaptics_i2c_reg_get(touch->client, DATA_REG0);
360 gesture = (data >> GESTURE) & 0x1;
361
362 /*
363 * Get Relative axes. we have to get them in one shot,
364 * so we get 2 bytes starting from REL_X_REG.
365 */
366 xy_delta = synaptics_i2c_word_get(touch->client, REL_X_REG) & 0xffff;
367
368 /* Separate X from Y */
369 x_delta = xy_delta & 0xff;
370 y_delta = (xy_delta >> REGISTER_LENGTH) & 0xff;
371
372 /* Report the button event */
373 input_report_key(input, BTN_LEFT, gesture);
374
375 /* Report the deltas */
376 input_report_rel(input, REL_X, x_delta);
377 input_report_rel(input, REL_Y, -y_delta);
378 input_sync(input);
379
380 return xy_delta || gesture;
381}
382
383static irqreturn_t synaptics_i2c_irq(int irq, void *dev_id)
384{
385 struct synaptics_i2c *touch = dev_id;
386
387 mod_delayed_work(system_dfl_wq, &touch->dwork, 0);
388
389 return IRQ_HANDLED;
390}
391
392static void synaptics_i2c_check_params(struct synaptics_i2c *touch)
393{
394 bool reset = false;
395
396 if (scan_rate != touch->scan_rate_param)
397 set_scan_rate(touch, scan_rate);
398
399 if (no_decel != touch->no_decel_param) {
400 touch->no_decel_param = no_decel;
401 reset = true;
402 }
403
404 if (no_filter != touch->no_filter_param) {
405 touch->no_filter_param = no_filter;
406 reset = true;
407 }
408
409 if (reduce_report != touch->reduce_report_param) {
410 touch->reduce_report_param = reduce_report;
411 reset = true;
412 }
413
414 if (reset)
415 synaptics_i2c_reset_config(touch->client);
416}
417
418/* Control the Device polling rate / Work Handler sleep time */
419static unsigned long synaptics_i2c_adjust_delay(struct synaptics_i2c *touch,
420 bool have_data)
421{
422 unsigned long delay, nodata_count_thres;
423
424 if (polling_req) {
425 delay = touch->scan_ms;
426 if (have_data) {
427 touch->no_data_count = 0;
428 } else {
429 nodata_count_thres = NO_DATA_THRES / touch->scan_ms;
430 if (touch->no_data_count < nodata_count_thres)
431 touch->no_data_count++;
432 else
433 delay = NO_DATA_SLEEP_MSECS;
434 }
435 return msecs_to_jiffies(delay);
436 }
437
438 delay = msecs_to_jiffies(THREAD_IRQ_SLEEP_MSECS);
439 return round_jiffies_relative(delay);
440}
441
442/* Work Handler */
443static void synaptics_i2c_work_handler(struct work_struct *work)
444{
445 bool have_data;
446 struct synaptics_i2c *touch =
447 container_of(work, struct synaptics_i2c, dwork.work);
448 unsigned long delay;
449
450 synaptics_i2c_check_params(touch);
451
452 have_data = synaptics_i2c_get_input(touch);
453 delay = synaptics_i2c_adjust_delay(touch, have_data);
454
455 /*
456 * While interrupt driven, there is no real need to poll the device.
457 * But touchpads are very sensitive, so there could be errors
458 * related to physical environment and the attention line isn't
459 * necessarily asserted. In such case we can lose the touchpad.
460 * We poll the device once in THREAD_IRQ_SLEEP_SECS and
461 * if error is detected, we try to reset and reconfigure the touchpad.
462 */
463 mod_delayed_work(system_dfl_wq, &touch->dwork, delay);
464}
465
466static int synaptics_i2c_open(struct input_dev *input)
467{
468 struct synaptics_i2c *touch = input_get_drvdata(input);
469 int error;
470
471 error = synaptics_i2c_reset_config(touch->client);
472 if (error)
473 return error;
474
475 if (polling_req)
476 mod_delayed_work(system_dfl_wq, &touch->dwork,
477 msecs_to_jiffies(NO_DATA_SLEEP_MSECS));
478
479 return 0;
480}
481
482static void synaptics_i2c_close(struct input_dev *input)
483{
484 struct synaptics_i2c *touch = input_get_drvdata(input);
485
486 if (!polling_req)
487 synaptics_i2c_reg_set(touch->client, INTERRUPT_EN_REG, 0);
488
489 cancel_delayed_work_sync(&touch->dwork);
490
491 /* Save some power */
492 synaptics_i2c_reg_set(touch->client, DEV_CONTROL_REG, DEEP_SLEEP);
493}
494
495static void synaptics_i2c_set_input_params(struct synaptics_i2c *touch)
496{
497 struct input_dev *input = touch->input;
498
499 input->name = touch->client->name;
500 input->phys = touch->client->adapter->name;
501 input->id.bustype = BUS_I2C;
502 input->id.version = synaptics_i2c_word_get(touch->client,
503 INFO_QUERY_REG0);
504 input->open = synaptics_i2c_open;
505 input->close = synaptics_i2c_close;
506 input_set_drvdata(input, touch);
507
508 /* Register the device as mouse */
509 input_set_capability(input, EV_REL, REL_X);
510 input_set_capability(input, EV_REL, REL_Y);
511
512 /* Register device's buttons and keys */
513 input_set_capability(input, EV_KEY, BTN_LEFT);
514}
515
516static int synaptics_i2c_probe(struct i2c_client *client)
517{
518 struct device *dev = &client->dev;
519 struct synaptics_i2c *touch;
520 int error;
521
522 touch = devm_kzalloc(dev, sizeof(*touch), GFP_KERNEL);
523 if (!touch)
524 return -ENOMEM;
525
526 touch->client = client;
527 touch->no_decel_param = no_decel;
528 touch->scan_rate_param = scan_rate;
529 set_scan_rate(touch, scan_rate);
530 INIT_DELAYED_WORK(&touch->dwork, synaptics_i2c_work_handler);
531
532 error = synaptics_i2c_reset_config(client);
533 if (error)
534 return error;
535
536 if (client->irq <= 0)
537 polling_req = true;
538
539 touch->input = devm_input_allocate_device(dev);
540 if (!touch->input)
541 return -ENOMEM;
542
543 synaptics_i2c_set_input_params(touch);
544
545 if (!polling_req) {
546 dev_dbg(dev, "Requesting IRQ: %d\n", client->irq);
547
548 error = devm_request_irq(dev, client->irq, synaptics_i2c_irq,
549 IRQ_TYPE_EDGE_FALLING,
550 DRIVER_NAME, touch);
551 if (error) {
552 dev_warn(dev, "IRQ request failed: %d, falling back to polling\n",
553 error);
554 polling_req = true;
555 synaptics_i2c_reg_set(client, INTERRUPT_EN_REG, 0);
556 }
557 }
558
559 if (polling_req)
560 dev_dbg(dev, "Using polling at rate: %d times/sec\n", scan_rate);
561
562 /* Register the device in input subsystem */
563 error = input_register_device(touch->input);
564 if (error) {
565 dev_err(dev, "Input device register failed: %d\n", error);
566 return error;
567 }
568
569 i2c_set_clientdata(client, touch);
570
571 return 0;
572}
573
574static int synaptics_i2c_suspend(struct device *dev)
575{
576 struct i2c_client *client = to_i2c_client(dev);
577 struct synaptics_i2c *touch = i2c_get_clientdata(client);
578
579 cancel_delayed_work_sync(&touch->dwork);
580
581 /* Save some power */
582 synaptics_i2c_reg_set(touch->client, DEV_CONTROL_REG, DEEP_SLEEP);
583
584 return 0;
585}
586
587static int synaptics_i2c_resume(struct device *dev)
588{
589 struct i2c_client *client = to_i2c_client(dev);
590 struct synaptics_i2c *touch = i2c_get_clientdata(client);
591 struct input_dev *input = touch->input;
592 int error;
593
594 error = synaptics_i2c_reset_config(client);
595 if (error)
596 return error;
597
598 guard(mutex)(&input->mutex);
599 if (input_device_enabled(input))
600 mod_delayed_work(system_dfl_wq, &touch->dwork,
601 msecs_to_jiffies(NO_DATA_SLEEP_MSECS));
602
603 return 0;
604}
605
606static DEFINE_SIMPLE_DEV_PM_OPS(synaptics_i2c_pm, synaptics_i2c_suspend,
607 synaptics_i2c_resume);
608
609static const struct i2c_device_id synaptics_i2c_id_table[] = {
610 { .name = "synaptics_i2c" },
611 { }
612};
613MODULE_DEVICE_TABLE(i2c, synaptics_i2c_id_table);
614
615#ifdef CONFIG_OF
616static const struct of_device_id synaptics_i2c_of_match[] = {
617 { .compatible = "synaptics,synaptics_i2c", },
618 { },
619};
620MODULE_DEVICE_TABLE(of, synaptics_i2c_of_match);
621#endif
622
623static struct i2c_driver synaptics_i2c_driver = {
624 .driver = {
625 .name = DRIVER_NAME,
626 .of_match_table = of_match_ptr(synaptics_i2c_of_match),
627 .pm = pm_sleep_ptr(&synaptics_i2c_pm),
628 },
629
630 .probe = synaptics_i2c_probe,
631 .id_table = synaptics_i2c_id_table,
632};
633
634module_i2c_driver(synaptics_i2c_driver);
635
636MODULE_DESCRIPTION("Synaptics I2C touchpad driver");
637MODULE_AUTHOR("Mike Rapoport, Igor Grinberg, Compulab");
638MODULE_LICENSE("GPL");
639