1 // SPDX-License-Identifier: GPL-2.0
2 // STMicroelectronics FTS Touchscreen device driver
4 // Copyright (c) 2017 Samsung Electronics Co., Ltd.
5 // Copyright (c) 2017 Andi Shyti <andi@etezian.org>
7 #include <linux/delay.h>
9 #include <linux/input/mt.h>
10 #include <linux/input/touchscreen.h>
11 #include <linux/interrupt.h>
12 #include <linux/irq.h>
13 #include <linux/leds.h>
14 #include <linux/module.h>
15 #include <linux/pm_runtime.h>
16 #include <linux/regulator/consumer.h>
19 #define STMFTS_READ_INFO 0x80
20 #define STMFTS_READ_STATUS 0x84
21 #define STMFTS_READ_ONE_EVENT 0x85
22 #define STMFTS_READ_ALL_EVENT 0x86
23 #define STMFTS_LATEST_EVENT 0x87
24 #define STMFTS_SLEEP_IN 0x90
25 #define STMFTS_SLEEP_OUT 0x91
26 #define STMFTS_MS_MT_SENSE_OFF 0x92
27 #define STMFTS_MS_MT_SENSE_ON 0x93
28 #define STMFTS_SS_HOVER_SENSE_OFF 0x94
29 #define STMFTS_SS_HOVER_SENSE_ON 0x95
30 #define STMFTS_MS_KEY_SENSE_OFF 0x9a
31 #define STMFTS_MS_KEY_SENSE_ON 0x9b
32 #define STMFTS_SYSTEM_RESET 0xa0
33 #define STMFTS_CLEAR_EVENT_STACK 0xa1
34 #define STMFTS_FULL_FORCE_CALIBRATION 0xa2
35 #define STMFTS_MS_CX_TUNING 0xa3
36 #define STMFTS_SS_CX_TUNING 0xa4
39 #define STMFTS_EV_NO_EVENT 0x00
40 #define STMFTS_EV_MULTI_TOUCH_DETECTED 0x02
41 #define STMFTS_EV_MULTI_TOUCH_ENTER 0x03
42 #define STMFTS_EV_MULTI_TOUCH_LEAVE 0x04
43 #define STMFTS_EV_MULTI_TOUCH_MOTION 0x05
44 #define STMFTS_EV_HOVER_ENTER 0x07
45 #define STMFTS_EV_HOVER_LEAVE 0x08
46 #define STMFTS_EV_HOVER_MOTION 0x09
47 #define STMFTS_EV_KEY_STATUS 0x0e
48 #define STMFTS_EV_ERROR 0x0f
49 #define STMFTS_EV_CONTROLLER_READY 0x10
50 #define STMFTS_EV_SLEEP_OUT_CONTROLLER_READY 0x11
51 #define STMFTS_EV_STATUS 0x16
52 #define STMFTS_EV_DEBUG 0xdb
54 /* multi touch related event masks */
55 #define STMFTS_MASK_EVENT_ID 0x0f
56 #define STMFTS_MASK_TOUCH_ID 0xf0
57 #define STMFTS_MASK_LEFT_EVENT 0x0f
58 #define STMFTS_MASK_X_MSB 0x0f
59 #define STMFTS_MASK_Y_LSB 0xf0
61 /* key related event masks */
62 #define STMFTS_MASK_KEY_NO_TOUCH 0x00
63 #define STMFTS_MASK_KEY_MENU 0x01
64 #define STMFTS_MASK_KEY_BACK 0x02
66 #define STMFTS_EVENT_SIZE 8
67 #define STMFTS_STACK_DEPTH 32
68 #define STMFTS_DATA_MAX_SIZE (STMFTS_EVENT_SIZE * STMFTS_STACK_DEPTH)
69 #define STMFTS_MAX_FINGERS 10
70 #define STMFTS_DEV_NAME "stmfts"
72 enum stmfts_regulators {
74 STMFTS_REGULATOR_AVDD,
78 struct i2c_client *client;
79 struct input_dev *input;
80 struct led_classdev led_cdev;
83 struct touchscreen_properties prop;
85 struct regulator_bulk_data regulators[2];
88 * Presence of ledvdd will be used also to check
89 * whether the LED is supported.
91 struct regulator *ledvdd;
99 u8 data[STMFTS_DATA_MAX_SIZE];
101 struct completion cmd_done;
109 static int stmfts_brightness_set(struct led_classdev *led_cdev,
110 enum led_brightness value)
112 struct stmfts_data *sdata = container_of(led_cdev,
113 struct stmfts_data, led_cdev);
116 if (value != sdata->led_status && sdata->ledvdd) {
118 regulator_disable(sdata->ledvdd);
120 err = regulator_enable(sdata->ledvdd);
122 dev_warn(&sdata->client->dev,
123 "failed to disable ledvdd regulator: %d\n",
128 sdata->led_status = value;
134 static enum led_brightness stmfts_brightness_get(struct led_classdev *led_cdev)
136 struct stmfts_data *sdata = container_of(led_cdev,
137 struct stmfts_data, led_cdev);
139 return !!regulator_is_enabled(sdata->ledvdd);
143 * We can't simply use i2c_smbus_read_i2c_block_data because we
144 * need to read more than 255 bytes (
146 static int stmfts_read_events(struct stmfts_data *sdata)
148 u8 cmd = STMFTS_READ_ALL_EVENT;
149 struct i2c_msg msgs[2] = {
151 .addr = sdata->client->addr,
156 .addr = sdata->client->addr,
158 .len = STMFTS_DATA_MAX_SIZE,
164 ret = i2c_transfer(sdata->client->adapter, msgs, ARRAY_SIZE(msgs));
168 return ret == ARRAY_SIZE(msgs) ? 0 : -EIO;
171 static void stmfts_report_contact_event(struct stmfts_data *sdata,
174 u8 slot_id = (event[0] & STMFTS_MASK_TOUCH_ID) >> 4;
175 u16 x = event[1] | ((event[2] & STMFTS_MASK_X_MSB) << 8);
176 u16 y = (event[2] >> 4) | (event[3] << 4);
179 u8 orientation = event[6];
182 input_mt_slot(sdata->input, slot_id);
184 input_mt_report_slot_state(sdata->input, MT_TOOL_FINGER, true);
185 input_report_abs(sdata->input, ABS_MT_POSITION_X, x);
186 input_report_abs(sdata->input, ABS_MT_POSITION_Y, y);
187 input_report_abs(sdata->input, ABS_MT_TOUCH_MAJOR, maj);
188 input_report_abs(sdata->input, ABS_MT_TOUCH_MINOR, min);
189 input_report_abs(sdata->input, ABS_MT_PRESSURE, area);
190 input_report_abs(sdata->input, ABS_MT_ORIENTATION, orientation);
192 input_sync(sdata->input);
195 static void stmfts_report_contact_release(struct stmfts_data *sdata,
198 u8 slot_id = (event[0] & STMFTS_MASK_TOUCH_ID) >> 4;
200 input_mt_slot(sdata->input, slot_id);
201 input_mt_report_slot_inactive(sdata->input);
203 input_sync(sdata->input);
206 static void stmfts_report_hover_event(struct stmfts_data *sdata,
209 u16 x = (event[2] << 4) | (event[4] >> 4);
210 u16 y = (event[3] << 4) | (event[4] & STMFTS_MASK_Y_LSB);
213 input_report_abs(sdata->input, ABS_X, x);
214 input_report_abs(sdata->input, ABS_Y, y);
215 input_report_abs(sdata->input, ABS_DISTANCE, z);
217 input_sync(sdata->input);
220 static void stmfts_report_key_event(struct stmfts_data *sdata, const u8 event[])
224 input_report_key(sdata->input, KEY_BACK, 0);
225 input_report_key(sdata->input, KEY_MENU, 0);
228 case STMFTS_MASK_KEY_BACK:
229 input_report_key(sdata->input, KEY_BACK, 1);
232 case STMFTS_MASK_KEY_MENU:
233 input_report_key(sdata->input, KEY_MENU, 1);
237 dev_warn(&sdata->client->dev,
238 "unknown key event: %#02x\n", event[2]);
242 input_sync(sdata->input);
245 static void stmfts_parse_events(struct stmfts_data *sdata)
249 for (i = 0; i < STMFTS_STACK_DEPTH; i++) {
250 u8 *event = &sdata->data[i * STMFTS_EVENT_SIZE];
254 case STMFTS_EV_CONTROLLER_READY:
255 case STMFTS_EV_SLEEP_OUT_CONTROLLER_READY:
256 case STMFTS_EV_STATUS:
257 complete(&sdata->cmd_done);
260 case STMFTS_EV_NO_EVENT:
261 case STMFTS_EV_DEBUG:
265 switch (event[0] & STMFTS_MASK_EVENT_ID) {
267 case STMFTS_EV_MULTI_TOUCH_ENTER:
268 case STMFTS_EV_MULTI_TOUCH_MOTION:
269 stmfts_report_contact_event(sdata, event);
272 case STMFTS_EV_MULTI_TOUCH_LEAVE:
273 stmfts_report_contact_release(sdata, event);
276 case STMFTS_EV_HOVER_ENTER:
277 case STMFTS_EV_HOVER_LEAVE:
278 case STMFTS_EV_HOVER_MOTION:
279 stmfts_report_hover_event(sdata, event);
282 case STMFTS_EV_KEY_STATUS:
283 stmfts_report_key_event(sdata, event);
286 case STMFTS_EV_ERROR:
287 dev_warn(&sdata->client->dev,
288 "error code: 0x%x%x%x%x%x%x",
289 event[6], event[5], event[4],
290 event[3], event[2], event[1]);
294 dev_err(&sdata->client->dev,
295 "unknown event %#02x\n", event[0]);
300 static irqreturn_t stmfts_irq_handler(int irq, void *dev)
302 struct stmfts_data *sdata = dev;
305 mutex_lock(&sdata->mutex);
307 err = stmfts_read_events(sdata);
309 dev_err(&sdata->client->dev,
310 "failed to read events: %d\n", err);
312 stmfts_parse_events(sdata);
314 mutex_unlock(&sdata->mutex);
318 static int stmfts_command(struct stmfts_data *sdata, const u8 cmd)
322 reinit_completion(&sdata->cmd_done);
324 err = i2c_smbus_write_byte(sdata->client, cmd);
328 if (!wait_for_completion_timeout(&sdata->cmd_done,
329 msecs_to_jiffies(1000)))
335 static int stmfts_input_open(struct input_dev *dev)
337 struct stmfts_data *sdata = input_get_drvdata(dev);
340 err = pm_runtime_resume_and_get(&sdata->client->dev);
344 err = i2c_smbus_write_byte(sdata->client, STMFTS_MS_MT_SENSE_ON);
346 pm_runtime_put_sync(&sdata->client->dev);
350 mutex_lock(&sdata->mutex);
351 sdata->running = true;
353 if (sdata->hover_enabled) {
354 err = i2c_smbus_write_byte(sdata->client,
355 STMFTS_SS_HOVER_SENSE_ON);
357 dev_warn(&sdata->client->dev,
358 "failed to enable hover\n");
360 mutex_unlock(&sdata->mutex);
362 if (sdata->use_key) {
363 err = i2c_smbus_write_byte(sdata->client,
364 STMFTS_MS_KEY_SENSE_ON);
366 /* I can still use only the touch screen */
367 dev_warn(&sdata->client->dev,
368 "failed to enable touchkey\n");
374 static void stmfts_input_close(struct input_dev *dev)
376 struct stmfts_data *sdata = input_get_drvdata(dev);
379 err = i2c_smbus_write_byte(sdata->client, STMFTS_MS_MT_SENSE_OFF);
381 dev_warn(&sdata->client->dev,
382 "failed to disable touchscreen: %d\n", err);
384 mutex_lock(&sdata->mutex);
386 sdata->running = false;
388 if (sdata->hover_enabled) {
389 err = i2c_smbus_write_byte(sdata->client,
390 STMFTS_SS_HOVER_SENSE_OFF);
392 dev_warn(&sdata->client->dev,
393 "failed to disable hover: %d\n", err);
395 mutex_unlock(&sdata->mutex);
397 if (sdata->use_key) {
398 err = i2c_smbus_write_byte(sdata->client,
399 STMFTS_MS_KEY_SENSE_OFF);
401 dev_warn(&sdata->client->dev,
402 "failed to disable touchkey: %d\n", err);
405 pm_runtime_put_sync(&sdata->client->dev);
408 static ssize_t stmfts_sysfs_chip_id(struct device *dev,
409 struct device_attribute *attr, char *buf)
411 struct stmfts_data *sdata = dev_get_drvdata(dev);
413 return sprintf(buf, "%#x\n", sdata->chip_id);
416 static ssize_t stmfts_sysfs_chip_version(struct device *dev,
417 struct device_attribute *attr, char *buf)
419 struct stmfts_data *sdata = dev_get_drvdata(dev);
421 return sprintf(buf, "%u\n", sdata->chip_ver);
424 static ssize_t stmfts_sysfs_fw_ver(struct device *dev,
425 struct device_attribute *attr, char *buf)
427 struct stmfts_data *sdata = dev_get_drvdata(dev);
429 return sprintf(buf, "%u\n", sdata->fw_ver);
432 static ssize_t stmfts_sysfs_config_id(struct device *dev,
433 struct device_attribute *attr, char *buf)
435 struct stmfts_data *sdata = dev_get_drvdata(dev);
437 return sprintf(buf, "%#x\n", sdata->config_id);
440 static ssize_t stmfts_sysfs_config_version(struct device *dev,
441 struct device_attribute *attr, char *buf)
443 struct stmfts_data *sdata = dev_get_drvdata(dev);
445 return sprintf(buf, "%u\n", sdata->config_ver);
448 static ssize_t stmfts_sysfs_read_status(struct device *dev,
449 struct device_attribute *attr, char *buf)
451 struct stmfts_data *sdata = dev_get_drvdata(dev);
455 err = i2c_smbus_read_i2c_block_data(sdata->client, STMFTS_READ_STATUS,
456 sizeof(status), status);
460 return sprintf(buf, "%#02x\n", status[0]);
463 static ssize_t stmfts_sysfs_hover_enable_read(struct device *dev,
464 struct device_attribute *attr, char *buf)
466 struct stmfts_data *sdata = dev_get_drvdata(dev);
468 return sprintf(buf, "%u\n", sdata->hover_enabled);
471 static ssize_t stmfts_sysfs_hover_enable_write(struct device *dev,
472 struct device_attribute *attr,
473 const char *buf, size_t len)
475 struct stmfts_data *sdata = dev_get_drvdata(dev);
479 if (kstrtoul(buf, 0, &value))
482 mutex_lock(&sdata->mutex);
484 if (value && sdata->hover_enabled)
488 err = i2c_smbus_write_byte(sdata->client,
489 value ? STMFTS_SS_HOVER_SENSE_ON :
490 STMFTS_SS_HOVER_SENSE_OFF);
493 sdata->hover_enabled = !!value;
496 mutex_unlock(&sdata->mutex);
501 static DEVICE_ATTR(chip_id, 0444, stmfts_sysfs_chip_id, NULL);
502 static DEVICE_ATTR(chip_version, 0444, stmfts_sysfs_chip_version, NULL);
503 static DEVICE_ATTR(fw_ver, 0444, stmfts_sysfs_fw_ver, NULL);
504 static DEVICE_ATTR(config_id, 0444, stmfts_sysfs_config_id, NULL);
505 static DEVICE_ATTR(config_version, 0444, stmfts_sysfs_config_version, NULL);
506 static DEVICE_ATTR(status, 0444, stmfts_sysfs_read_status, NULL);
507 static DEVICE_ATTR(hover_enable, 0644, stmfts_sysfs_hover_enable_read,
508 stmfts_sysfs_hover_enable_write);
510 static struct attribute *stmfts_sysfs_attrs[] = {
511 &dev_attr_chip_id.attr,
512 &dev_attr_chip_version.attr,
513 &dev_attr_fw_ver.attr,
514 &dev_attr_config_id.attr,
515 &dev_attr_config_version.attr,
516 &dev_attr_status.attr,
517 &dev_attr_hover_enable.attr,
520 ATTRIBUTE_GROUPS(stmfts_sysfs);
522 static int stmfts_power_on(struct stmfts_data *sdata)
527 err = regulator_bulk_enable(ARRAY_SIZE(sdata->regulators),
533 * The datasheet does not specify the power on time, but considering
534 * that the reset time is < 10ms, I sleep 20ms to be sure
538 err = i2c_smbus_read_i2c_block_data(sdata->client, STMFTS_READ_INFO,
542 if (err != sizeof(reg))
545 sdata->chip_id = be16_to_cpup((__be16 *)®[6]);
546 sdata->chip_ver = reg[0];
547 sdata->fw_ver = be16_to_cpup((__be16 *)®[2]);
548 sdata->config_id = reg[4];
549 sdata->config_ver = reg[5];
551 enable_irq(sdata->client->irq);
555 err = stmfts_command(sdata, STMFTS_SYSTEM_RESET);
559 err = stmfts_command(sdata, STMFTS_SLEEP_OUT);
563 /* optional tuning */
564 err = stmfts_command(sdata, STMFTS_MS_CX_TUNING);
566 dev_warn(&sdata->client->dev,
567 "failed to perform mutual auto tune: %d\n", err);
569 /* optional tuning */
570 err = stmfts_command(sdata, STMFTS_SS_CX_TUNING);
572 dev_warn(&sdata->client->dev,
573 "failed to perform self auto tune: %d\n", err);
575 err = stmfts_command(sdata, STMFTS_FULL_FORCE_CALIBRATION);
580 * At this point no one is using the touchscreen
581 * and I don't really care about the return value
583 (void) i2c_smbus_write_byte(sdata->client, STMFTS_SLEEP_IN);
588 static void stmfts_power_off(void *data)
590 struct stmfts_data *sdata = data;
592 disable_irq(sdata->client->irq);
593 regulator_bulk_disable(ARRAY_SIZE(sdata->regulators),
597 /* This function is void because I don't want to prevent using the touch key
598 * only because the LEDs don't get registered
600 static int stmfts_enable_led(struct stmfts_data *sdata)
604 /* get the regulator for powering the leds on */
605 sdata->ledvdd = devm_regulator_get(&sdata->client->dev, "ledvdd");
606 if (IS_ERR(sdata->ledvdd))
607 return PTR_ERR(sdata->ledvdd);
609 sdata->led_cdev.name = STMFTS_DEV_NAME;
610 sdata->led_cdev.max_brightness = LED_ON;
611 sdata->led_cdev.brightness = LED_OFF;
612 sdata->led_cdev.brightness_set_blocking = stmfts_brightness_set;
613 sdata->led_cdev.brightness_get = stmfts_brightness_get;
615 err = devm_led_classdev_register(&sdata->client->dev, &sdata->led_cdev);
617 devm_regulator_put(sdata->ledvdd);
624 static int stmfts_probe(struct i2c_client *client)
627 struct stmfts_data *sdata;
629 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C |
630 I2C_FUNC_SMBUS_BYTE_DATA |
631 I2C_FUNC_SMBUS_I2C_BLOCK))
634 sdata = devm_kzalloc(&client->dev, sizeof(*sdata), GFP_KERNEL);
638 i2c_set_clientdata(client, sdata);
640 sdata->client = client;
641 mutex_init(&sdata->mutex);
642 init_completion(&sdata->cmd_done);
644 sdata->regulators[STMFTS_REGULATOR_VDD].supply = "vdd";
645 sdata->regulators[STMFTS_REGULATOR_AVDD].supply = "avdd";
646 err = devm_regulator_bulk_get(&client->dev,
647 ARRAY_SIZE(sdata->regulators),
652 sdata->input = devm_input_allocate_device(&client->dev);
656 sdata->input->name = STMFTS_DEV_NAME;
657 sdata->input->id.bustype = BUS_I2C;
658 sdata->input->open = stmfts_input_open;
659 sdata->input->close = stmfts_input_close;
661 input_set_capability(sdata->input, EV_ABS, ABS_MT_POSITION_X);
662 input_set_capability(sdata->input, EV_ABS, ABS_MT_POSITION_Y);
663 touchscreen_parse_properties(sdata->input, true, &sdata->prop);
665 input_set_abs_params(sdata->input, ABS_MT_TOUCH_MAJOR, 0, 255, 0, 0);
666 input_set_abs_params(sdata->input, ABS_MT_TOUCH_MINOR, 0, 255, 0, 0);
667 input_set_abs_params(sdata->input, ABS_MT_ORIENTATION, 0, 255, 0, 0);
668 input_set_abs_params(sdata->input, ABS_MT_PRESSURE, 0, 255, 0, 0);
669 input_set_abs_params(sdata->input, ABS_DISTANCE, 0, 255, 0, 0);
671 sdata->use_key = device_property_read_bool(&client->dev,
672 "touch-key-connected");
673 if (sdata->use_key) {
674 input_set_capability(sdata->input, EV_KEY, KEY_MENU);
675 input_set_capability(sdata->input, EV_KEY, KEY_BACK);
678 err = input_mt_init_slots(sdata->input,
679 STMFTS_MAX_FINGERS, INPUT_MT_DIRECT);
683 input_set_drvdata(sdata->input, sdata);
686 * stmfts_power_on expects interrupt to be disabled, but
687 * at this point the device is still off and I do not trust
688 * the status of the irq line that can generate some spurious
689 * interrupts. To be on the safe side it's better to not enable
690 * the interrupts during their request.
692 err = devm_request_threaded_irq(&client->dev, client->irq,
693 NULL, stmfts_irq_handler,
694 IRQF_ONESHOT | IRQF_NO_AUTOEN,
695 "stmfts_irq", sdata);
699 dev_dbg(&client->dev, "initializing ST-Microelectronics FTS...\n");
701 err = stmfts_power_on(sdata);
705 err = devm_add_action_or_reset(&client->dev, stmfts_power_off, sdata);
709 err = input_register_device(sdata->input);
713 if (sdata->use_key) {
714 err = stmfts_enable_led(sdata);
717 * Even if the LEDs have failed to be initialized and
718 * used in the driver, I can still use the device even
719 * without LEDs. The ledvdd regulator pointer will be
722 dev_warn(&client->dev, "unable to use touchkey leds\n");
723 sdata->ledvdd = NULL;
727 pm_runtime_enable(&client->dev);
728 device_enable_async_suspend(&client->dev);
733 static void stmfts_remove(struct i2c_client *client)
735 pm_runtime_disable(&client->dev);
738 static int stmfts_runtime_suspend(struct device *dev)
740 struct stmfts_data *sdata = dev_get_drvdata(dev);
743 ret = i2c_smbus_write_byte(sdata->client, STMFTS_SLEEP_IN);
745 dev_warn(dev, "failed to suspend device: %d\n", ret);
750 static int stmfts_runtime_resume(struct device *dev)
752 struct stmfts_data *sdata = dev_get_drvdata(dev);
755 ret = i2c_smbus_write_byte(sdata->client, STMFTS_SLEEP_OUT);
757 dev_err(dev, "failed to resume device: %d\n", ret);
762 static int stmfts_suspend(struct device *dev)
764 struct stmfts_data *sdata = dev_get_drvdata(dev);
766 stmfts_power_off(sdata);
771 static int stmfts_resume(struct device *dev)
773 struct stmfts_data *sdata = dev_get_drvdata(dev);
775 return stmfts_power_on(sdata);
778 static const struct dev_pm_ops stmfts_pm_ops = {
779 SYSTEM_SLEEP_PM_OPS(stmfts_suspend, stmfts_resume)
780 RUNTIME_PM_OPS(stmfts_runtime_suspend, stmfts_runtime_resume, NULL)
784 static const struct of_device_id stmfts_of_match[] = {
785 { .compatible = "st,stmfts", },
788 MODULE_DEVICE_TABLE(of, stmfts_of_match);
791 static const struct i2c_device_id stmfts_id[] = {
795 MODULE_DEVICE_TABLE(i2c, stmfts_id);
797 static struct i2c_driver stmfts_driver = {
799 .name = STMFTS_DEV_NAME,
800 .dev_groups = stmfts_sysfs_groups,
801 .of_match_table = of_match_ptr(stmfts_of_match),
802 .pm = pm_ptr(&stmfts_pm_ops),
803 .probe_type = PROBE_PREFER_ASYNCHRONOUS,
805 .probe = stmfts_probe,
806 .remove = stmfts_remove,
807 .id_table = stmfts_id,
810 module_i2c_driver(stmfts_driver);
812 MODULE_AUTHOR("Andi Shyti <andi.shyti@samsung.com>");
813 MODULE_DESCRIPTION("STMicroelectronics FTS Touch Screen");
814 MODULE_LICENSE("GPL v2");