2 * Synaptics touchpad with I2C interface
4 * Copyright (C) 2009 Compulab, Ltd.
5 * Mike Rapoport <mike@compulab.co.il>
6 * Igor Grinberg <grinberg@compulab.co.il>
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
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>
22 #define DRIVER_NAME "synaptics_i2c"
23 /* maximum product id is 15 characters */
24 #define PRODUCT_ID_LENGTH 15
25 #define REGISTER_LENGTH 8
28 * after soft reset, we should wait for 1 ms
29 * before the device becomes operational
31 #define SOFT_RESET_DELAY_MS 3
32 /* and after hard reset, we should wait for max 500ms */
33 #define HARD_RESET_DELAY_MS 500
35 /* Registers by SMBus address */
36 #define PAGE_SEL_REG 0xff
37 #define DEVICE_STATUS_REG 0x09
39 /* Registers by RMI address */
40 #define DEV_CONTROL_REG 0x0000
41 #define INTERRUPT_EN_REG 0x0001
42 #define ERR_STAT_REG 0x0002
43 #define INT_REQ_STAT_REG 0x0003
44 #define DEV_COMMAND_REG 0x0004
46 #define RMI_PROT_VER_REG 0x0200
47 #define MANUFACT_ID_REG 0x0201
48 #define PHYS_INT_VER_REG 0x0202
49 #define PROD_PROPERTY_REG 0x0203
50 #define INFO_QUERY_REG0 0x0204
51 #define INFO_QUERY_REG1 (INFO_QUERY_REG0 + 1)
52 #define INFO_QUERY_REG2 (INFO_QUERY_REG0 + 2)
53 #define INFO_QUERY_REG3 (INFO_QUERY_REG0 + 3)
55 #define PRODUCT_ID_REG0 0x0210
56 #define PRODUCT_ID_REG1 (PRODUCT_ID_REG0 + 1)
57 #define PRODUCT_ID_REG2 (PRODUCT_ID_REG0 + 2)
58 #define PRODUCT_ID_REG3 (PRODUCT_ID_REG0 + 3)
59 #define PRODUCT_ID_REG4 (PRODUCT_ID_REG0 + 4)
60 #define PRODUCT_ID_REG5 (PRODUCT_ID_REG0 + 5)
61 #define PRODUCT_ID_REG6 (PRODUCT_ID_REG0 + 6)
62 #define PRODUCT_ID_REG7 (PRODUCT_ID_REG0 + 7)
63 #define PRODUCT_ID_REG8 (PRODUCT_ID_REG0 + 8)
64 #define PRODUCT_ID_REG9 (PRODUCT_ID_REG0 + 9)
65 #define PRODUCT_ID_REG10 (PRODUCT_ID_REG0 + 10)
66 #define PRODUCT_ID_REG11 (PRODUCT_ID_REG0 + 11)
67 #define PRODUCT_ID_REG12 (PRODUCT_ID_REG0 + 12)
68 #define PRODUCT_ID_REG13 (PRODUCT_ID_REG0 + 13)
69 #define PRODUCT_ID_REG14 (PRODUCT_ID_REG0 + 14)
70 #define PRODUCT_ID_REG15 (PRODUCT_ID_REG0 + 15)
72 #define DATA_REG0 0x0400
73 #define ABS_PRESSURE_REG 0x0401
74 #define ABS_MSB_X_REG 0x0402
75 #define ABS_LSB_X_REG (ABS_MSB_X_REG + 1)
76 #define ABS_MSB_Y_REG 0x0404
77 #define ABS_LSB_Y_REG (ABS_MSB_Y_REG + 1)
78 #define REL_X_REG 0x0406
79 #define REL_Y_REG 0x0407
81 #define DEV_QUERY_REG0 0x1000
82 #define DEV_QUERY_REG1 (DEV_QUERY_REG0 + 1)
83 #define DEV_QUERY_REG2 (DEV_QUERY_REG0 + 2)
84 #define DEV_QUERY_REG3 (DEV_QUERY_REG0 + 3)
85 #define DEV_QUERY_REG4 (DEV_QUERY_REG0 + 4)
86 #define DEV_QUERY_REG5 (DEV_QUERY_REG0 + 5)
87 #define DEV_QUERY_REG6 (DEV_QUERY_REG0 + 6)
88 #define DEV_QUERY_REG7 (DEV_QUERY_REG0 + 7)
89 #define DEV_QUERY_REG8 (DEV_QUERY_REG0 + 8)
91 #define GENERAL_2D_CONTROL_REG 0x1041
92 #define SENSOR_SENSITIVITY_REG 0x1044
93 #define SENS_MAX_POS_MSB_REG 0x1046
94 #define SENS_MAX_POS_LSB_REG (SENS_MAX_POS_UPPER_REG + 1)
97 /* Device Control Register Bits */
98 #define REPORT_RATE_1ST_BIT 6
100 /* Interrupt Enable Register Bits (INTERRUPT_EN_REG) */
101 #define F10_ABS_INT_ENA 0
102 #define F10_REL_INT_ENA 1
103 #define F20_INT_ENA 2
105 /* Interrupt Request Register Bits (INT_REQ_STAT_REG | DEVICE_STATUS_REG) */
106 #define F10_ABS_INT_REQ 0
107 #define F10_REL_INT_REQ 1
108 #define F20_INT_REQ 2
109 /* Device Status Register Bits (DEVICE_STATUS_REG) */
110 #define STAT_CONFIGURED 6
113 /* Device Command Register Bits (DEV_COMMAND_REG) */
114 #define RESET_COMMAND 0x01
115 #define REZERO_COMMAND 0x02
117 /* Data Register 0 Bits (DATA_REG0) */
120 /* Device Query Registers Bits */
122 #define HAS_PALM_DETECT 1
123 #define HAS_MULTI_FING 2
124 #define HAS_SCROLLER 4
125 #define HAS_2D_SCROLL 5
127 /* General 2D Control Register Bits (GENERAL_2D_CONTROL_REG) */
128 #define NO_DECELERATION 1
129 #define REDUCE_REPORTING 3
133 /* Device Control Register Masks (DEV_CONTROL_REG) */
134 #define REPORT_RATE_MSK 0xc0
135 #define SLEEP_MODE_MSK 0x07
137 /* Device Sleep Modes */
138 #define FULL_AWAKE 0x0
139 #define NORMAL_OP 0x1
140 #define LOW_PWR_OP 0x2
141 #define VERY_LOW_PWR_OP 0x3
142 #define SENS_SLEEP 0x4
143 #define SLEEP_MOD 0x5
144 #define DEEP_SLEEP 0x6
145 #define HIBERNATE 0x7
147 /* Interrupt Register Mask */
148 /* (INT_REQ_STAT_REG | DEVICE_STATUS_REG | INTERRUPT_EN_REG) */
149 #define INT_ENA_REQ_MSK 0x07
150 #define INT_ENA_ABS_MSK 0x01
151 #define INT_ENA_REL_MSK 0x02
152 #define INT_ENA_F20_MSK 0x04
154 /* Device Status Register Masks (DEVICE_STATUS_REG) */
155 #define CONFIGURED_MSK 0x40
156 #define ERROR_MSK 0x80
158 /* Data Register 0 Masks */
159 #define FINGER_WIDTH_MSK 0xf0
160 #define GESTURE_MSK 0x08
161 #define SENSOR_STATUS_MSK 0x07
164 * MSB Position Register Masks
165 * ABS_MSB_X_REG | ABS_MSB_Y_REG | SENS_MAX_POS_MSB_REG |
166 * DEV_QUERY_REG3 | DEV_QUERY_REG5
168 #define MSB_POSITION_MSK 0x1f
170 /* Device Query Registers Masks */
173 #define NUM_EXTRA_POS_MSK 0x07
175 /* When in IRQ mode read the device every THREAD_IRQ_SLEEP_SECS */
176 #define THREAD_IRQ_SLEEP_SECS 2
177 #define THREAD_IRQ_SLEEP_MSECS (THREAD_IRQ_SLEEP_SECS * MSEC_PER_SEC)
180 * When in Polling mode and no data received for NO_DATA_THRES msecs
181 * reduce the polling rate to NO_DATA_SLEEP_MSECS
183 #define NO_DATA_THRES (MSEC_PER_SEC)
184 #define NO_DATA_SLEEP_MSECS (MSEC_PER_SEC / 4)
186 /* Control touchpad's No Deceleration option */
187 static int no_decel = 1;
188 module_param(no_decel, bool, 0644);
189 MODULE_PARM_DESC(no_decel, "No Deceleration. Default = 1 (on)");
191 /* Control touchpad's Reduced Reporting option */
192 static int reduce_report;
193 module_param(reduce_report, bool, 0644);
194 MODULE_PARM_DESC(reduce_report, "Reduced Reporting. Default = 0 (off)");
196 /* Control touchpad's No Filter option */
197 static int no_filter;
198 module_param(no_filter, bool, 0644);
199 MODULE_PARM_DESC(no_filter, "No Filter. Default = 0 (off)");
202 * touchpad Attention line is Active Low and Open Drain,
203 * therefore should be connected to pulled up line
204 * and the irq configuration should be set to Falling Edge Trigger
206 /* Control IRQ / Polling option */
207 static bool polling_req;
208 module_param(polling_req, bool, 0444);
209 MODULE_PARM_DESC(polling_req, "Request Polling. Default = 0 (use irq)");
211 /* Control Polling Rate */
212 static int scan_rate = 80;
213 module_param(scan_rate, int, 0644);
214 MODULE_PARM_DESC(scan_rate, "Polling rate in times/sec. Default = 80");
216 /* The main device structure */
217 struct synaptics_i2c {
218 struct i2c_client *client;
219 struct input_dev *input;
220 struct delayed_work dwork;
224 int reduce_report_param;
230 static inline void set_scan_rate(struct synaptics_i2c *touch, int scan_rate)
232 touch->scan_ms = MSEC_PER_SEC / scan_rate;
233 touch->scan_rate_param = scan_rate;
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.
241 static s32 synaptics_i2c_reg_get(struct i2c_client *client, u16 reg)
245 ret = i2c_smbus_write_byte_data(client, PAGE_SEL_REG, reg >> 8);
247 ret = i2c_smbus_read_byte_data(client, reg & 0xff);
252 static s32 synaptics_i2c_reg_set(struct i2c_client *client, u16 reg, u8 val)
256 ret = i2c_smbus_write_byte_data(client, PAGE_SEL_REG, reg >> 8);
258 ret = i2c_smbus_write_byte_data(client, reg & 0xff, val);
263 static s32 synaptics_i2c_word_get(struct i2c_client *client, u16 reg)
267 ret = i2c_smbus_write_byte_data(client, PAGE_SEL_REG, reg >> 8);
269 ret = i2c_smbus_read_word_data(client, reg & 0xff);
274 static int synaptics_i2c_config(struct i2c_client *client)
279 /* set Report Rate to Device Highest (>=80) and Sleep to normal */
280 ret = synaptics_i2c_reg_set(client, DEV_CONTROL_REG, 0xc1);
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);
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;
296 control |= no_filter ? 1 << NO_FILTER : 0;
297 ret = synaptics_i2c_reg_set(client, GENERAL_2D_CONTROL_REG, control);
304 static int synaptics_i2c_reset_config(struct i2c_client *client)
308 /* Reset the Touchpad */
309 ret = synaptics_i2c_reg_set(client, DEV_COMMAND_REG, RESET_COMMAND);
311 dev_err(&client->dev, "Unable to reset device\n");
313 msleep(SOFT_RESET_DELAY_MS);
314 ret = synaptics_i2c_config(client);
316 dev_err(&client->dev, "Unable to config device\n");
322 static int synaptics_i2c_check_error(struct i2c_client *client)
326 status = i2c_smbus_read_byte_data(client, DEVICE_STATUS_REG) &
327 (CONFIGURED_MSK | ERROR_MSK);
329 if (status != CONFIGURED_MSK)
330 ret = synaptics_i2c_reset_config(client);
335 static bool synaptics_i2c_get_input(struct synaptics_i2c *touch)
337 struct input_dev *input = touch->input;
338 int xy_delta, gesture;
342 /* Deal with spontanious resets and errors */
343 if (synaptics_i2c_check_error(touch->client))
346 /* Get Gesture Bit */
347 data = synaptics_i2c_reg_get(touch->client, DATA_REG0);
348 gesture = (data >> GESTURE) & 0x1;
351 * Get Relative axes. we have to get them in one shot,
352 * so we get 2 bytes starting from REL_X_REG.
354 xy_delta = synaptics_i2c_word_get(touch->client, REL_X_REG) & 0xffff;
356 /* Separate X from Y */
357 x_delta = xy_delta & 0xff;
358 y_delta = (xy_delta >> REGISTER_LENGTH) & 0xff;
360 /* Report the button event */
361 input_report_key(input, BTN_LEFT, gesture);
363 /* Report the deltas */
364 input_report_rel(input, REL_X, x_delta);
365 input_report_rel(input, REL_Y, -y_delta);
368 return xy_delta || gesture;
371 static void synaptics_i2c_reschedule_work(struct synaptics_i2c *touch,
376 spin_lock_irqsave(&touch->lock, flags);
379 * If work is already scheduled then subsequent schedules will not
380 * change the scheduled time that's why we have to cancel it first.
382 __cancel_delayed_work(&touch->dwork);
383 schedule_delayed_work(&touch->dwork, delay);
385 spin_unlock_irqrestore(&touch->lock, flags);
388 static irqreturn_t synaptics_i2c_irq(int irq, void *dev_id)
390 struct synaptics_i2c *touch = dev_id;
392 synaptics_i2c_reschedule_work(touch, 0);
397 static void synaptics_i2c_check_params(struct synaptics_i2c *touch)
401 if (scan_rate != touch->scan_rate_param)
402 set_scan_rate(touch, scan_rate);
404 if (no_decel != touch->no_decel_param) {
405 touch->no_decel_param = no_decel;
409 if (no_filter != touch->no_filter_param) {
410 touch->no_filter_param = no_filter;
414 if (reduce_report != touch->reduce_report_param) {
415 touch->reduce_report_param = reduce_report;
420 synaptics_i2c_reset_config(touch->client);
423 /* Control the Device polling rate / Work Handler sleep time */
424 static unsigned long synaptics_i2c_adjust_delay(struct synaptics_i2c *touch,
427 unsigned long delay, nodata_count_thres;
430 delay = touch->scan_ms;
432 touch->no_data_count = 0;
434 nodata_count_thres = NO_DATA_THRES / touch->scan_ms;
435 if (touch->no_data_count < nodata_count_thres)
436 touch->no_data_count++;
438 delay = NO_DATA_SLEEP_MSECS;
440 return msecs_to_jiffies(delay);
442 delay = msecs_to_jiffies(THREAD_IRQ_SLEEP_MSECS);
443 return round_jiffies_relative(delay);
448 static void synaptics_i2c_work_handler(struct work_struct *work)
451 struct synaptics_i2c *touch =
452 container_of(work, struct synaptics_i2c, dwork.work);
455 synaptics_i2c_check_params(touch);
457 have_data = synaptics_i2c_get_input(touch);
458 delay = synaptics_i2c_adjust_delay(touch, have_data);
461 * While interrupt driven, there is no real need to poll the device.
462 * But touchpads are very sensitive, so there could be errors
463 * related to physical environment and the attention line isn't
464 * neccesarily asserted. In such case we can lose the touchpad.
465 * We poll the device once in THREAD_IRQ_SLEEP_SECS and
466 * if error is detected, we try to reset and reconfigure the touchpad.
468 synaptics_i2c_reschedule_work(touch, delay);
471 static int synaptics_i2c_open(struct input_dev *input)
473 struct synaptics_i2c *touch = input_get_drvdata(input);
476 ret = synaptics_i2c_reset_config(touch->client);
481 synaptics_i2c_reschedule_work(touch,
482 msecs_to_jiffies(NO_DATA_SLEEP_MSECS));
487 static void synaptics_i2c_close(struct input_dev *input)
489 struct synaptics_i2c *touch = input_get_drvdata(input);
492 synaptics_i2c_reg_set(touch->client, INTERRUPT_EN_REG, 0);
494 cancel_delayed_work_sync(&touch->dwork);
496 /* Save some power */
497 synaptics_i2c_reg_set(touch->client, DEV_CONTROL_REG, DEEP_SLEEP);
500 static void synaptics_i2c_set_input_params(struct synaptics_i2c *touch)
502 struct input_dev *input = touch->input;
504 input->name = touch->client->name;
505 input->phys = touch->client->adapter->name;
506 input->id.bustype = BUS_I2C;
507 input->id.version = synaptics_i2c_word_get(touch->client,
509 input->dev.parent = &touch->client->dev;
510 input->open = synaptics_i2c_open;
511 input->close = synaptics_i2c_close;
512 input_set_drvdata(input, touch);
514 /* Register the device as mouse */
515 __set_bit(EV_REL, input->evbit);
516 __set_bit(REL_X, input->relbit);
517 __set_bit(REL_Y, input->relbit);
519 /* Register device's buttons and keys */
520 __set_bit(EV_KEY, input->evbit);
521 __set_bit(BTN_LEFT, input->keybit);
524 static struct synaptics_i2c *synaptics_i2c_touch_create(struct i2c_client *client)
526 struct synaptics_i2c *touch;
528 touch = kzalloc(sizeof(struct synaptics_i2c), GFP_KERNEL);
532 touch->client = client;
533 touch->no_decel_param = no_decel;
534 touch->scan_rate_param = scan_rate;
535 set_scan_rate(touch, scan_rate);
536 INIT_DELAYED_WORK(&touch->dwork, synaptics_i2c_work_handler);
537 spin_lock_init(&touch->lock);
542 static int __devinit synaptics_i2c_probe(struct i2c_client *client,
543 const struct i2c_device_id *dev_id)
546 struct synaptics_i2c *touch;
548 touch = synaptics_i2c_touch_create(client);
552 ret = synaptics_i2c_reset_config(client);
559 touch->input = input_allocate_device();
565 synaptics_i2c_set_input_params(touch);
568 dev_dbg(&touch->client->dev,
569 "Requesting IRQ: %d\n", touch->client->irq);
571 ret = request_irq(touch->client->irq, synaptics_i2c_irq,
572 IRQF_DISABLED|IRQ_TYPE_EDGE_FALLING,
575 dev_warn(&touch->client->dev,
576 "IRQ request failed: %d, "
577 "falling back to polling\n", ret);
579 synaptics_i2c_reg_set(touch->client,
580 INTERRUPT_EN_REG, 0);
585 dev_dbg(&touch->client->dev,
586 "Using polling at rate: %d times/sec\n", scan_rate);
588 /* Register the device in input subsystem */
589 ret = input_register_device(touch->input);
591 dev_err(&client->dev,
592 "Input device register failed: %d\n", ret);
596 i2c_set_clientdata(client, touch);
601 input_free_device(touch->input);
608 static int __devexit synaptics_i2c_remove(struct i2c_client *client)
610 struct synaptics_i2c *touch = i2c_get_clientdata(client);
613 free_irq(client->irq, touch);
615 input_unregister_device(touch->input);
616 i2c_set_clientdata(client, NULL);
623 static int synaptics_i2c_suspend(struct i2c_client *client, pm_message_t mesg)
625 struct synaptics_i2c *touch = i2c_get_clientdata(client);
627 cancel_delayed_work_sync(&touch->dwork);
629 /* Save some power */
630 synaptics_i2c_reg_set(touch->client, DEV_CONTROL_REG, DEEP_SLEEP);
635 static int synaptics_i2c_resume(struct i2c_client *client)
638 struct synaptics_i2c *touch = i2c_get_clientdata(client);
640 ret = synaptics_i2c_reset_config(client);
644 synaptics_i2c_reschedule_work(touch,
645 msecs_to_jiffies(NO_DATA_SLEEP_MSECS));
650 #define synaptics_i2c_suspend NULL
651 #define synaptics_i2c_resume NULL
654 static const struct i2c_device_id synaptics_i2c_id_table[] = {
655 { "synaptics_i2c", 0 },
658 MODULE_DEVICE_TABLE(i2c, synaptics_i2c_id_table);
660 static struct i2c_driver synaptics_i2c_driver = {
663 .owner = THIS_MODULE,
666 .probe = synaptics_i2c_probe,
667 .remove = __devexit_p(synaptics_i2c_remove),
669 .suspend = synaptics_i2c_suspend,
670 .resume = synaptics_i2c_resume,
671 .id_table = synaptics_i2c_id_table,
674 static int __init synaptics_i2c_init(void)
676 return i2c_add_driver(&synaptics_i2c_driver);
679 static void __exit synaptics_i2c_exit(void)
681 i2c_del_driver(&synaptics_i2c_driver);
684 module_init(synaptics_i2c_init);
685 module_exit(synaptics_i2c_exit);
687 MODULE_DESCRIPTION("Synaptics I2C touchpad driver");
688 MODULE_AUTHOR("Mike Rapoport, Igor Grinberg, Compulab");
689 MODULE_LICENSE("GPL");