2 * Synaptics touchpad with I2C interface
4 * Copyright (C) 2009 Compulab, Ltd.
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>
23 #define DRIVER_NAME "synaptics_i2c"
24 /* maximum product id is 15 characters */
25 #define PRODUCT_ID_LENGTH 15
26 #define REGISTER_LENGTH 8
29 * after soft reset, we should wait for 1 ms
30 * before the device becomes operational
32 #define SOFT_RESET_DELAY_MS 3
33 /* and after hard reset, we should wait for max 500ms */
34 #define HARD_RESET_DELAY_MS 500
36 /* Registers by SMBus address */
37 #define PAGE_SEL_REG 0xff
38 #define DEVICE_STATUS_REG 0x09
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
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)
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)
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
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)
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)
98 /* Device Control Register Bits */
99 #define REPORT_RATE_1ST_BIT 6
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
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
114 /* Device Command Register Bits (DEV_COMMAND_REG) */
115 #define RESET_COMMAND 0x01
116 #define REZERO_COMMAND 0x02
118 /* Data Register 0 Bits (DATA_REG0) */
121 /* Device Query Registers Bits */
123 #define HAS_PALM_DETECT 1
124 #define HAS_MULTI_FING 2
125 #define HAS_SCROLLER 4
126 #define HAS_2D_SCROLL 5
128 /* General 2D Control Register Bits (GENERAL_2D_CONTROL_REG) */
129 #define NO_DECELERATION 1
130 #define REDUCE_REPORTING 3
134 /* Device Control Register Masks (DEV_CONTROL_REG) */
135 #define REPORT_RATE_MSK 0xc0
136 #define SLEEP_MODE_MSK 0x07
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
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
155 /* Device Status Register Masks (DEVICE_STATUS_REG) */
156 #define CONFIGURED_MSK 0x40
157 #define ERROR_MSK 0x80
159 /* Data Register 0 Masks */
160 #define FINGER_WIDTH_MSK 0xf0
161 #define GESTURE_MSK 0x08
162 #define SENSOR_STATUS_MSK 0x07
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
169 #define MSB_POSITION_MSK 0x1f
171 /* Device Query Registers Masks */
174 #define NUM_EXTRA_POS_MSK 0x07
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)
181 * When in Polling mode and no data received for NO_DATA_THRES msecs
182 * reduce the polling rate to NO_DATA_SLEEP_MSECS
184 #define NO_DATA_THRES (MSEC_PER_SEC)
185 #define NO_DATA_SLEEP_MSECS (MSEC_PER_SEC / 4)
187 /* Control touchpad's No Deceleration option */
188 static bool no_decel = true;
189 module_param(no_decel, bool, 0644);
190 MODULE_PARM_DESC(no_decel, "No Deceleration. Default = 1 (on)");
192 /* Control touchpad's Reduced Reporting option */
193 static bool reduce_report;
194 module_param(reduce_report, bool, 0644);
195 MODULE_PARM_DESC(reduce_report, "Reduced Reporting. Default = 0 (off)");
197 /* Control touchpad's No Filter option */
198 static bool no_filter;
199 module_param(no_filter, bool, 0644);
200 MODULE_PARM_DESC(no_filter, "No Filter. Default = 0 (off)");
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
207 /* Control IRQ / Polling option */
208 static bool polling_req;
209 module_param(polling_req, bool, 0444);
210 MODULE_PARM_DESC(polling_req, "Request Polling. Default = 0 (use irq)");
212 /* Control Polling Rate */
213 static int scan_rate = 80;
214 module_param(scan_rate, int, 0644);
215 MODULE_PARM_DESC(scan_rate, "Polling rate in times/sec. Default = 80");
217 /* The main device structure */
218 struct synaptics_i2c {
219 struct i2c_client *client;
220 struct input_dev *input;
221 struct delayed_work dwork;
225 int reduce_report_param;
231 static inline void set_scan_rate(struct synaptics_i2c *touch, int scan_rate)
233 touch->scan_ms = MSEC_PER_SEC / scan_rate;
234 touch->scan_rate_param = scan_rate;
238 * Driver's initial design makes no race condition possible on i2c bus,
239 * so there is no need in any locking.
240 * Keep it in mind, while playing with the code.
242 static s32 synaptics_i2c_reg_get(struct i2c_client *client, u16 reg)
246 ret = i2c_smbus_write_byte_data(client, PAGE_SEL_REG, reg >> 8);
248 ret = i2c_smbus_read_byte_data(client, reg & 0xff);
253 static s32 synaptics_i2c_reg_set(struct i2c_client *client, u16 reg, u8 val)
257 ret = i2c_smbus_write_byte_data(client, PAGE_SEL_REG, reg >> 8);
259 ret = i2c_smbus_write_byte_data(client, reg & 0xff, val);
264 static s32 synaptics_i2c_word_get(struct i2c_client *client, u16 reg)
268 ret = i2c_smbus_write_byte_data(client, PAGE_SEL_REG, reg >> 8);
270 ret = i2c_smbus_read_word_data(client, reg & 0xff);
275 static int synaptics_i2c_config(struct i2c_client *client)
280 /* set Report Rate to Device Highest (>=80) and Sleep to normal */
281 ret = synaptics_i2c_reg_set(client, DEV_CONTROL_REG, 0xc1);
285 /* set Interrupt Disable to Func20 / Enable to Func10) */
286 int_en = (polling_req) ? 0 : INT_ENA_ABS_MSK | INT_ENA_REL_MSK;
287 ret = synaptics_i2c_reg_set(client, INTERRUPT_EN_REG, int_en);
291 control = synaptics_i2c_reg_get(client, GENERAL_2D_CONTROL_REG);
292 /* No Deceleration */
293 control |= no_decel ? 1 << NO_DECELERATION : 0;
294 /* Reduced Reporting */
295 control |= reduce_report ? 1 << REDUCE_REPORTING : 0;
297 control |= no_filter ? 1 << NO_FILTER : 0;
298 ret = synaptics_i2c_reg_set(client, GENERAL_2D_CONTROL_REG, control);
305 static int synaptics_i2c_reset_config(struct i2c_client *client)
309 /* Reset the Touchpad */
310 ret = synaptics_i2c_reg_set(client, DEV_COMMAND_REG, RESET_COMMAND);
312 dev_err(&client->dev, "Unable to reset device\n");
314 msleep(SOFT_RESET_DELAY_MS);
315 ret = synaptics_i2c_config(client);
317 dev_err(&client->dev, "Unable to config device\n");
323 static int synaptics_i2c_check_error(struct i2c_client *client)
327 status = i2c_smbus_read_byte_data(client, DEVICE_STATUS_REG) &
328 (CONFIGURED_MSK | ERROR_MSK);
330 if (status != CONFIGURED_MSK)
331 ret = synaptics_i2c_reset_config(client);
336 static bool synaptics_i2c_get_input(struct synaptics_i2c *touch)
338 struct input_dev *input = touch->input;
339 int xy_delta, gesture;
343 /* Deal with spontaneous resets and errors */
344 if (synaptics_i2c_check_error(touch->client))
347 /* Get Gesture Bit */
348 data = synaptics_i2c_reg_get(touch->client, DATA_REG0);
349 gesture = (data >> GESTURE) & 0x1;
352 * Get Relative axes. we have to get them in one shot,
353 * so we get 2 bytes starting from REL_X_REG.
355 xy_delta = synaptics_i2c_word_get(touch->client, REL_X_REG) & 0xffff;
357 /* Separate X from Y */
358 x_delta = xy_delta & 0xff;
359 y_delta = (xy_delta >> REGISTER_LENGTH) & 0xff;
361 /* Report the button event */
362 input_report_key(input, BTN_LEFT, gesture);
364 /* Report the deltas */
365 input_report_rel(input, REL_X, x_delta);
366 input_report_rel(input, REL_Y, -y_delta);
369 return xy_delta || gesture;
372 static void synaptics_i2c_reschedule_work(struct synaptics_i2c *touch,
377 spin_lock_irqsave(&touch->lock, flags);
379 mod_delayed_work(system_wq, &touch->dwork, delay);
381 spin_unlock_irqrestore(&touch->lock, flags);
384 static irqreturn_t synaptics_i2c_irq(int irq, void *dev_id)
386 struct synaptics_i2c *touch = dev_id;
388 synaptics_i2c_reschedule_work(touch, 0);
393 static void synaptics_i2c_check_params(struct synaptics_i2c *touch)
397 if (scan_rate != touch->scan_rate_param)
398 set_scan_rate(touch, scan_rate);
400 if (no_decel != touch->no_decel_param) {
401 touch->no_decel_param = no_decel;
405 if (no_filter != touch->no_filter_param) {
406 touch->no_filter_param = no_filter;
410 if (reduce_report != touch->reduce_report_param) {
411 touch->reduce_report_param = reduce_report;
416 synaptics_i2c_reset_config(touch->client);
419 /* Control the Device polling rate / Work Handler sleep time */
420 static unsigned long synaptics_i2c_adjust_delay(struct synaptics_i2c *touch,
423 unsigned long delay, nodata_count_thres;
426 delay = touch->scan_ms;
428 touch->no_data_count = 0;
430 nodata_count_thres = NO_DATA_THRES / touch->scan_ms;
431 if (touch->no_data_count < nodata_count_thres)
432 touch->no_data_count++;
434 delay = NO_DATA_SLEEP_MSECS;
436 return msecs_to_jiffies(delay);
438 delay = msecs_to_jiffies(THREAD_IRQ_SLEEP_MSECS);
439 return round_jiffies_relative(delay);
444 static void synaptics_i2c_work_handler(struct work_struct *work)
447 struct synaptics_i2c *touch =
448 container_of(work, struct synaptics_i2c, dwork.work);
451 synaptics_i2c_check_params(touch);
453 have_data = synaptics_i2c_get_input(touch);
454 delay = synaptics_i2c_adjust_delay(touch, have_data);
457 * While interrupt driven, there is no real need to poll the device.
458 * But touchpads are very sensitive, so there could be errors
459 * related to physical environment and the attention line isn't
460 * necessarily asserted. In such case we can lose the touchpad.
461 * We poll the device once in THREAD_IRQ_SLEEP_SECS and
462 * if error is detected, we try to reset and reconfigure the touchpad.
464 synaptics_i2c_reschedule_work(touch, delay);
467 static int synaptics_i2c_open(struct input_dev *input)
469 struct synaptics_i2c *touch = input_get_drvdata(input);
472 ret = synaptics_i2c_reset_config(touch->client);
477 synaptics_i2c_reschedule_work(touch,
478 msecs_to_jiffies(NO_DATA_SLEEP_MSECS));
483 static void synaptics_i2c_close(struct input_dev *input)
485 struct synaptics_i2c *touch = input_get_drvdata(input);
488 synaptics_i2c_reg_set(touch->client, INTERRUPT_EN_REG, 0);
490 cancel_delayed_work_sync(&touch->dwork);
492 /* Save some power */
493 synaptics_i2c_reg_set(touch->client, DEV_CONTROL_REG, DEEP_SLEEP);
496 static void synaptics_i2c_set_input_params(struct synaptics_i2c *touch)
498 struct input_dev *input = touch->input;
500 input->name = touch->client->name;
501 input->phys = touch->client->adapter->name;
502 input->id.bustype = BUS_I2C;
503 input->id.version = synaptics_i2c_word_get(touch->client,
505 input->dev.parent = &touch->client->dev;
506 input->open = synaptics_i2c_open;
507 input->close = synaptics_i2c_close;
508 input_set_drvdata(input, touch);
510 /* Register the device as mouse */
511 __set_bit(EV_REL, input->evbit);
512 __set_bit(REL_X, input->relbit);
513 __set_bit(REL_Y, input->relbit);
515 /* Register device's buttons and keys */
516 __set_bit(EV_KEY, input->evbit);
517 __set_bit(BTN_LEFT, input->keybit);
520 static struct synaptics_i2c *synaptics_i2c_touch_create(struct i2c_client *client)
522 struct synaptics_i2c *touch;
524 touch = kzalloc(sizeof(struct synaptics_i2c), GFP_KERNEL);
528 touch->client = client;
529 touch->no_decel_param = no_decel;
530 touch->scan_rate_param = scan_rate;
531 set_scan_rate(touch, scan_rate);
532 INIT_DELAYED_WORK(&touch->dwork, synaptics_i2c_work_handler);
533 spin_lock_init(&touch->lock);
538 static int synaptics_i2c_probe(struct i2c_client *client,
539 const struct i2c_device_id *dev_id)
542 struct synaptics_i2c *touch;
544 touch = synaptics_i2c_touch_create(client);
548 ret = synaptics_i2c_reset_config(client);
555 touch->input = input_allocate_device();
561 synaptics_i2c_set_input_params(touch);
564 dev_dbg(&touch->client->dev,
565 "Requesting IRQ: %d\n", touch->client->irq);
567 ret = request_irq(touch->client->irq, synaptics_i2c_irq,
568 IRQ_TYPE_EDGE_FALLING,
571 dev_warn(&touch->client->dev,
572 "IRQ request failed: %d, "
573 "falling back to polling\n", ret);
575 synaptics_i2c_reg_set(touch->client,
576 INTERRUPT_EN_REG, 0);
581 dev_dbg(&touch->client->dev,
582 "Using polling at rate: %d times/sec\n", scan_rate);
584 /* Register the device in input subsystem */
585 ret = input_register_device(touch->input);
587 dev_err(&client->dev,
588 "Input device register failed: %d\n", ret);
592 i2c_set_clientdata(client, touch);
597 input_free_device(touch->input);
604 static int synaptics_i2c_remove(struct i2c_client *client)
606 struct synaptics_i2c *touch = i2c_get_clientdata(client);
609 free_irq(client->irq, touch);
611 input_unregister_device(touch->input);
617 static int __maybe_unused synaptics_i2c_suspend(struct device *dev)
619 struct i2c_client *client = to_i2c_client(dev);
620 struct synaptics_i2c *touch = i2c_get_clientdata(client);
622 cancel_delayed_work_sync(&touch->dwork);
624 /* Save some power */
625 synaptics_i2c_reg_set(touch->client, DEV_CONTROL_REG, DEEP_SLEEP);
630 static int __maybe_unused synaptics_i2c_resume(struct device *dev)
633 struct i2c_client *client = to_i2c_client(dev);
634 struct synaptics_i2c *touch = i2c_get_clientdata(client);
636 ret = synaptics_i2c_reset_config(client);
640 synaptics_i2c_reschedule_work(touch,
641 msecs_to_jiffies(NO_DATA_SLEEP_MSECS));
646 static SIMPLE_DEV_PM_OPS(synaptics_i2c_pm, synaptics_i2c_suspend,
647 synaptics_i2c_resume);
649 static const struct i2c_device_id synaptics_i2c_id_table[] = {
650 { "synaptics_i2c", 0 },
653 MODULE_DEVICE_TABLE(i2c, synaptics_i2c_id_table);
655 static struct i2c_driver synaptics_i2c_driver = {
658 .pm = &synaptics_i2c_pm,
661 .probe = synaptics_i2c_probe,
662 .remove = synaptics_i2c_remove,
664 .id_table = synaptics_i2c_id_table,
667 module_i2c_driver(synaptics_i2c_driver);
669 MODULE_DESCRIPTION("Synaptics I2C touchpad driver");
670 MODULE_AUTHOR("Mike Rapoport, Igor Grinberg, Compulab");
671 MODULE_LICENSE("GPL");