1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Microchip AT42QT1050 QTouch Sensor Controller
4 *
5 * Copyright (C) 2019 Pengutronix, Marco Felsch <kernel@pengutronix.de>
6 *
7 * Base on AT42QT1070 driver by:
8 * Bo Shen <voice.shen@atmel.com>
9 * Copyright (C) 2011 Atmel
10 */
11
12#include <linux/delay.h>
13#include <linux/i2c.h>
14#include <linux/input.h>
15#include <linux/interrupt.h>
16#include <linux/kernel.h>
17#include <linux/log2.h>
18#include <linux/module.h>
19#include <linux/of.h>
20#include <linux/regmap.h>
21
22/* Chip ID */
23#define QT1050_CHIP_ID 0x00
24#define QT1050_CHIP_ID_VER 0x46
25
26/* Firmware version */
27#define QT1050_FW_VERSION 0x01
28
29/* Detection status */
30#define QT1050_DET_STATUS 0x02
31
32/* Key status */
33#define QT1050_KEY_STATUS 0x03
34
35/* Key Signals */
36#define QT1050_KEY_SIGNAL_0_MSB 0x06
37#define QT1050_KEY_SIGNAL_0_LSB 0x07
38#define QT1050_KEY_SIGNAL_1_MSB 0x08
39#define QT1050_KEY_SIGNAL_1_LSB 0x09
40#define QT1050_KEY_SIGNAL_2_MSB 0x0c
41#define QT1050_KEY_SIGNAL_2_LSB 0x0d
42#define QT1050_KEY_SIGNAL_3_MSB 0x0e
43#define QT1050_KEY_SIGNAL_3_LSB 0x0f
44#define QT1050_KEY_SIGNAL_4_MSB 0x10
45#define QT1050_KEY_SIGNAL_4_LSB 0x11
46
47/* Reference data */
48#define QT1050_REF_DATA_0_MSB 0x14
49#define QT1050_REF_DATA_0_LSB 0x15
50#define QT1050_REF_DATA_1_MSB 0x16
51#define QT1050_REF_DATA_1_LSB 0x17
52#define QT1050_REF_DATA_2_MSB 0x1a
53#define QT1050_REF_DATA_2_LSB 0x1b
54#define QT1050_REF_DATA_3_MSB 0x1c
55#define QT1050_REF_DATA_3_LSB 0x1d
56#define QT1050_REF_DATA_4_MSB 0x1e
57#define QT1050_REF_DATA_4_LSB 0x1f
58
59/* Negative threshold level */
60#define QT1050_NTHR_0 0x21
61#define QT1050_NTHR_1 0x22
62#define QT1050_NTHR_2 0x24
63#define QT1050_NTHR_3 0x25
64#define QT1050_NTHR_4 0x26
65
66/* Pulse / Scale */
67#define QT1050_PULSE_SCALE_0 0x28
68#define QT1050_PULSE_SCALE_1 0x29
69#define QT1050_PULSE_SCALE_2 0x2b
70#define QT1050_PULSE_SCALE_3 0x2c
71#define QT1050_PULSE_SCALE_4 0x2d
72
73/* Detection integrator counter / AKS */
74#define QT1050_DI_AKS_0 0x2f
75#define QT1050_DI_AKS_1 0x30
76#define QT1050_DI_AKS_2 0x32
77#define QT1050_DI_AKS_3 0x33
78#define QT1050_DI_AKS_4 0x34
79
80/* Charge Share Delay */
81#define QT1050_CSD_0 0x36
82#define QT1050_CSD_1 0x37
83#define QT1050_CSD_2 0x39
84#define QT1050_CSD_3 0x3a
85#define QT1050_CSD_4 0x3b
86
87/* Low Power Mode */
88#define QT1050_LPMODE 0x3d
89
90/* Calibration and Reset */
91#define QT1050_RES_CAL 0x3f
92#define QT1050_RES_CAL_RESET BIT(7)
93#define QT1050_RES_CAL_CALIBRATE BIT(1)
94
95#define QT1050_MAX_KEYS 5
96#define QT1050_RESET_TIME 255
97
98struct qt1050_key_regs {
99 unsigned int nthr;
100 unsigned int pulse_scale;
101 unsigned int di_aks;
102 unsigned int csd;
103};
104
105struct qt1050_key {
106 u32 num;
107 u32 charge_delay;
108 u32 thr_cnt;
109 u32 samples;
110 u32 scale;
111 u32 keycode;
112};
113
114struct qt1050_priv {
115 struct i2c_client *client;
116 struct input_dev *input;
117 struct regmap *regmap;
118 struct qt1050_key keys[QT1050_MAX_KEYS];
119 unsigned short keycodes[QT1050_MAX_KEYS];
120 u8 reg_keys;
121 u8 last_keys;
122};
123
124static const struct qt1050_key_regs qt1050_key_regs_data[] = {
125 {
126 .nthr = QT1050_NTHR_0,
127 .pulse_scale = QT1050_PULSE_SCALE_0,
128 .di_aks = QT1050_DI_AKS_0,
129 .csd = QT1050_CSD_0,
130 }, {
131 .nthr = QT1050_NTHR_1,
132 .pulse_scale = QT1050_PULSE_SCALE_1,
133 .di_aks = QT1050_DI_AKS_1,
134 .csd = QT1050_CSD_1,
135 }, {
136 .nthr = QT1050_NTHR_2,
137 .pulse_scale = QT1050_PULSE_SCALE_2,
138 .di_aks = QT1050_DI_AKS_2,
139 .csd = QT1050_CSD_2,
140 }, {
141 .nthr = QT1050_NTHR_3,
142 .pulse_scale = QT1050_PULSE_SCALE_3,
143 .di_aks = QT1050_DI_AKS_3,
144 .csd = QT1050_CSD_3,
145 }, {
146 .nthr = QT1050_NTHR_4,
147 .pulse_scale = QT1050_PULSE_SCALE_4,
148 .di_aks = QT1050_DI_AKS_4,
149 .csd = QT1050_CSD_4,
150 }
151};
152
153static bool qt1050_volatile_reg(struct device *dev, unsigned int reg)
154{
155 switch (reg) {
156 case QT1050_DET_STATUS:
157 case QT1050_KEY_STATUS:
158 case QT1050_KEY_SIGNAL_0_MSB:
159 case QT1050_KEY_SIGNAL_0_LSB:
160 case QT1050_KEY_SIGNAL_1_MSB:
161 case QT1050_KEY_SIGNAL_1_LSB:
162 case QT1050_KEY_SIGNAL_2_MSB:
163 case QT1050_KEY_SIGNAL_2_LSB:
164 case QT1050_KEY_SIGNAL_3_MSB:
165 case QT1050_KEY_SIGNAL_3_LSB:
166 case QT1050_KEY_SIGNAL_4_MSB:
167 case QT1050_KEY_SIGNAL_4_LSB:
168 return true;
169 default:
170 return false;
171 }
172}
173
174static const struct regmap_range qt1050_readable_ranges[] = {
175 regmap_reg_range(QT1050_CHIP_ID, QT1050_KEY_STATUS),
176 regmap_reg_range(QT1050_KEY_SIGNAL_0_MSB, QT1050_KEY_SIGNAL_1_LSB),
177 regmap_reg_range(QT1050_KEY_SIGNAL_2_MSB, QT1050_KEY_SIGNAL_4_LSB),
178 regmap_reg_range(QT1050_REF_DATA_0_MSB, QT1050_REF_DATA_1_LSB),
179 regmap_reg_range(QT1050_REF_DATA_2_MSB, QT1050_REF_DATA_4_LSB),
180 regmap_reg_range(QT1050_NTHR_0, QT1050_NTHR_1),
181 regmap_reg_range(QT1050_NTHR_2, QT1050_NTHR_4),
182 regmap_reg_range(QT1050_PULSE_SCALE_0, QT1050_PULSE_SCALE_1),
183 regmap_reg_range(QT1050_PULSE_SCALE_2, QT1050_PULSE_SCALE_4),
184 regmap_reg_range(QT1050_DI_AKS_0, QT1050_DI_AKS_1),
185 regmap_reg_range(QT1050_DI_AKS_2, QT1050_DI_AKS_4),
186 regmap_reg_range(QT1050_CSD_0, QT1050_CSD_1),
187 regmap_reg_range(QT1050_CSD_2, QT1050_RES_CAL),
188};
189
190static const struct regmap_access_table qt1050_readable_table = {
191 .yes_ranges = qt1050_readable_ranges,
192 .n_yes_ranges = ARRAY_SIZE(qt1050_readable_ranges),
193};
194
195static const struct regmap_range qt1050_writeable_ranges[] = {
196 regmap_reg_range(QT1050_NTHR_0, QT1050_NTHR_1),
197 regmap_reg_range(QT1050_NTHR_2, QT1050_NTHR_4),
198 regmap_reg_range(QT1050_PULSE_SCALE_0, QT1050_PULSE_SCALE_1),
199 regmap_reg_range(QT1050_PULSE_SCALE_2, QT1050_PULSE_SCALE_4),
200 regmap_reg_range(QT1050_DI_AKS_0, QT1050_DI_AKS_1),
201 regmap_reg_range(QT1050_DI_AKS_2, QT1050_DI_AKS_4),
202 regmap_reg_range(QT1050_CSD_0, QT1050_CSD_1),
203 regmap_reg_range(QT1050_CSD_2, QT1050_RES_CAL),
204};
205
206static const struct regmap_access_table qt1050_writeable_table = {
207 .yes_ranges = qt1050_writeable_ranges,
208 .n_yes_ranges = ARRAY_SIZE(qt1050_writeable_ranges),
209};
210
211static const struct regmap_config qt1050_regmap_config = {
212 .reg_bits = 8,
213 .val_bits = 8,
214 .max_register = QT1050_RES_CAL,
215
216 .cache_type = REGCACHE_MAPLE,
217
218 .wr_table = &qt1050_writeable_table,
219 .rd_table = &qt1050_readable_table,
220 .volatile_reg = qt1050_volatile_reg,
221};
222
223static bool qt1050_identify(struct qt1050_priv *ts)
224{
225 unsigned int val;
226 int err;
227
228 /* Read Chip ID */
229 err = regmap_read(map: ts->regmap, QT1050_CHIP_ID, val: &val);
230 if (err) {
231 dev_err(&ts->client->dev, "Failed to read chip ID: %d\n", err);
232 return false;
233 }
234
235 if (val != QT1050_CHIP_ID_VER) {
236 dev_err(&ts->client->dev, "ID %d not supported\n", val);
237 return false;
238 }
239
240 /* Read firmware version */
241 err = regmap_read(map: ts->regmap, QT1050_FW_VERSION, val: &val);
242 if (err) {
243 dev_err(&ts->client->dev, "could not read the firmware version\n");
244 return false;
245 }
246
247 dev_info(&ts->client->dev, "AT42QT1050 firmware version %1d.%1d\n",
248 val >> 4, val & 0xf);
249
250 return true;
251}
252
253static irqreturn_t qt1050_irq_threaded(int irq, void *dev_id)
254{
255 struct qt1050_priv *ts = dev_id;
256 struct input_dev *input = ts->input;
257 unsigned long new_keys, changed;
258 unsigned int val;
259 int i, err;
260
261 /* Read the detected status register, thus clearing interrupt */
262 err = regmap_read(map: ts->regmap, QT1050_DET_STATUS, val: &val);
263 if (err) {
264 dev_err(&ts->client->dev, "Fail to read detection status: %d\n",
265 err);
266 return IRQ_NONE;
267 }
268
269 /* Read which key changed, keys are not continuous */
270 err = regmap_read(map: ts->regmap, QT1050_KEY_STATUS, val: &val);
271 if (err) {
272 dev_err(&ts->client->dev,
273 "Fail to determine the key status: %d\n", err);
274 return IRQ_NONE;
275 }
276 new_keys = (val & 0x70) >> 2 | (val & 0x6) >> 1;
277 changed = ts->last_keys ^ new_keys;
278 /* Report registered keys only */
279 changed &= ts->reg_keys;
280
281 for_each_set_bit(i, &changed, QT1050_MAX_KEYS)
282 input_report_key(dev: input, code: ts->keys[i].keycode,
283 test_bit(i, &new_keys));
284
285 ts->last_keys = new_keys;
286 input_sync(dev: input);
287
288 return IRQ_HANDLED;
289}
290
291static const struct qt1050_key_regs *qt1050_get_key_regs(int key_num)
292{
293 return &qt1050_key_regs_data[key_num];
294}
295
296static int qt1050_set_key(struct regmap *map, int number, int on)
297{
298 const struct qt1050_key_regs *key_regs;
299
300 key_regs = qt1050_get_key_regs(key_num: number);
301
302 return regmap_update_bits(map, reg: key_regs->di_aks, mask: 0xfc,
303 val: on ? BIT(4) : 0x00);
304}
305
306static int qt1050_apply_fw_data(struct qt1050_priv *ts)
307{
308 struct regmap *map = ts->regmap;
309 struct qt1050_key *button = &ts->keys[0];
310 const struct qt1050_key_regs *key_regs;
311 int i, err;
312
313 /* Disable all keys and enable only the specified ones */
314 for (i = 0; i < QT1050_MAX_KEYS; i++) {
315 err = qt1050_set_key(map, number: i, on: 0);
316 if (err)
317 return err;
318 }
319
320 for (i = 0; i < QT1050_MAX_KEYS; i++, button++) {
321 /* Keep KEY_RESERVED keys off */
322 if (button->keycode == KEY_RESERVED)
323 continue;
324
325 err = qt1050_set_key(map, number: button->num, on: 1);
326 if (err)
327 return err;
328
329 key_regs = qt1050_get_key_regs(key_num: button->num);
330
331 err = regmap_write(map, reg: key_regs->pulse_scale,
332 val: (button->samples << 4) | (button->scale));
333 if (err)
334 return err;
335 err = regmap_write(map, reg: key_regs->csd, val: button->charge_delay);
336 if (err)
337 return err;
338 err = regmap_write(map, reg: key_regs->nthr, val: button->thr_cnt);
339 if (err)
340 return err;
341 }
342
343 return 0;
344}
345
346static int qt1050_parse_fw(struct qt1050_priv *ts)
347{
348 struct device *dev = &ts->client->dev;
349 int nbuttons;
350
351 nbuttons = device_get_child_node_count(dev);
352 if (nbuttons == 0 || nbuttons > QT1050_MAX_KEYS)
353 return -ENODEV;
354
355 device_for_each_child_node_scoped(dev, child) {
356 struct qt1050_key button;
357
358 /* Required properties */
359 if (fwnode_property_read_u32(fwnode: child, propname: "linux,code",
360 val: &button.keycode)) {
361 dev_err(dev, "Button without keycode\n");
362 return -EINVAL;
363 }
364 if (button.keycode >= KEY_MAX) {
365 dev_err(dev, "Invalid keycode 0x%x\n",
366 button.keycode);
367 return -EINVAL;
368 }
369
370 if (fwnode_property_read_u32(fwnode: child, propname: "reg",
371 val: &button.num)) {
372 dev_err(dev, "Button without pad number\n");
373 return -EINVAL;
374 }
375 if (button.num < 0 || button.num > QT1050_MAX_KEYS - 1)
376 return -EINVAL;
377
378 ts->reg_keys |= BIT(button.num);
379
380 /* Optional properties */
381 if (fwnode_property_read_u32(fwnode: child,
382 propname: "microchip,pre-charge-time-ns",
383 val: &button.charge_delay)) {
384 button.charge_delay = 0;
385 } else {
386 if (button.charge_delay % 2500 == 0)
387 button.charge_delay =
388 button.charge_delay / 2500;
389 else
390 button.charge_delay = 0;
391 }
392
393 if (fwnode_property_read_u32(fwnode: child, propname: "microchip,average-samples",
394 val: &button.samples)) {
395 button.samples = 0;
396 } else {
397 if (is_power_of_2(n: button.samples))
398 button.samples = ilog2(button.samples);
399 else
400 button.samples = 0;
401 }
402
403 if (fwnode_property_read_u32(fwnode: child, propname: "microchip,average-scaling",
404 val: &button.scale)) {
405 button.scale = 0;
406 } else {
407 if (is_power_of_2(n: button.scale))
408 button.scale = ilog2(button.scale);
409 else
410 button.scale = 0;
411
412 }
413
414 if (fwnode_property_read_u32(fwnode: child, propname: "microchip,threshold",
415 val: &button.thr_cnt)) {
416 button.thr_cnt = 20;
417 } else {
418 if (button.thr_cnt > 255)
419 button.thr_cnt = 20;
420 }
421
422 ts->keys[button.num] = button;
423 }
424
425 return 0;
426}
427
428static int qt1050_probe(struct i2c_client *client)
429{
430 struct qt1050_priv *ts;
431 struct input_dev *input;
432 struct device *dev = &client->dev;
433 struct regmap *map;
434 unsigned int status, i;
435 int err;
436
437 /* Check basic functionality */
438 err = i2c_check_functionality(adap: client->adapter, I2C_FUNC_SMBUS_BYTE);
439 if (!err) {
440 dev_err(&client->dev, "%s adapter not supported\n",
441 dev_driver_string(&client->adapter->dev));
442 return -ENODEV;
443 }
444
445 if (!client->irq) {
446 dev_err(dev, "assign a irq line to this device\n");
447 return -EINVAL;
448 }
449
450 ts = devm_kzalloc(dev, size: sizeof(*ts), GFP_KERNEL);
451 if (!ts)
452 return -ENOMEM;
453
454 input = devm_input_allocate_device(dev);
455 if (!input)
456 return -ENOMEM;
457
458 map = devm_regmap_init_i2c(client, &qt1050_regmap_config);
459 if (IS_ERR(ptr: map))
460 return PTR_ERR(ptr: map);
461
462 ts->client = client;
463 ts->input = input;
464 ts->regmap = map;
465
466 i2c_set_clientdata(client, data: ts);
467
468 /* Identify the qt1050 chip */
469 if (!qt1050_identify(ts))
470 return -ENODEV;
471
472 /* Get pdata */
473 err = qt1050_parse_fw(ts);
474 if (err) {
475 dev_err(dev, "Failed to parse firmware: %d\n", err);
476 return err;
477 }
478
479 input->name = "AT42QT1050 QTouch Sensor";
480 input->dev.parent = &client->dev;
481 input->id.bustype = BUS_I2C;
482
483 /* Add the keycode */
484 input->keycode = ts->keycodes;
485 input->keycodesize = sizeof(ts->keycodes[0]);
486 input->keycodemax = QT1050_MAX_KEYS;
487
488 __set_bit(EV_KEY, input->evbit);
489 for (i = 0; i < QT1050_MAX_KEYS; i++) {
490 ts->keycodes[i] = ts->keys[i].keycode;
491 __set_bit(ts->keycodes[i], input->keybit);
492 }
493
494 /* Trigger re-calibration */
495 err = regmap_update_bits(map: ts->regmap, QT1050_RES_CAL, mask: 0x7f,
496 QT1050_RES_CAL_CALIBRATE);
497 if (err) {
498 dev_err(dev, "Trigger calibration failed: %d\n", err);
499 return err;
500 }
501 err = regmap_read_poll_timeout(ts->regmap, QT1050_DET_STATUS, status,
502 status >> 7 == 1, 10000, 200000);
503 if (err) {
504 dev_err(dev, "Calibration failed: %d\n", err);
505 return err;
506 }
507
508 /* Soft reset to set defaults */
509 err = regmap_update_bits(map: ts->regmap, QT1050_RES_CAL,
510 QT1050_RES_CAL_RESET, QT1050_RES_CAL_RESET);
511 if (err) {
512 dev_err(dev, "Trigger soft reset failed: %d\n", err);
513 return err;
514 }
515 msleep(QT1050_RESET_TIME);
516
517 /* Set pdata */
518 err = qt1050_apply_fw_data(ts);
519 if (err) {
520 dev_err(dev, "Failed to set firmware data: %d\n", err);
521 return err;
522 }
523
524 err = devm_request_threaded_irq(dev, irq: client->irq, NULL,
525 thread_fn: qt1050_irq_threaded, IRQF_ONESHOT,
526 devname: "qt1050", dev_id: ts);
527 if (err) {
528 dev_err(&client->dev, "Failed to request irq: %d\n", err);
529 return err;
530 }
531
532 /* Clear #CHANGE line */
533 err = regmap_read(map: ts->regmap, QT1050_DET_STATUS, val: &status);
534 if (err) {
535 dev_err(dev, "Failed to clear #CHANGE line level: %d\n", err);
536 return err;
537 }
538
539 /* Register the input device */
540 err = input_register_device(ts->input);
541 if (err) {
542 dev_err(&client->dev, "Failed to register input device: %d\n",
543 err);
544 return err;
545 }
546
547 return 0;
548}
549
550static int qt1050_suspend(struct device *dev)
551{
552 struct i2c_client *client = to_i2c_client(dev);
553 struct qt1050_priv *ts = i2c_get_clientdata(client);
554
555 disable_irq(irq: client->irq);
556
557 /*
558 * Set measurement interval to 1s (125 x 8ms) if wakeup is allowed
559 * else turn off. The 1s interval seems to be a good compromise between
560 * low power and response time.
561 */
562 return regmap_write(map: ts->regmap, QT1050_LPMODE,
563 val: device_may_wakeup(dev) ? 125 : 0);
564}
565
566static int qt1050_resume(struct device *dev)
567{
568 struct i2c_client *client = to_i2c_client(dev);
569 struct qt1050_priv *ts = i2c_get_clientdata(client);
570
571 enable_irq(irq: client->irq);
572
573 /* Set measurement interval back to 16ms (2 x 8ms) */
574 return regmap_write(map: ts->regmap, QT1050_LPMODE, val: 2);
575}
576
577static DEFINE_SIMPLE_DEV_PM_OPS(qt1050_pm_ops, qt1050_suspend, qt1050_resume);
578
579static const struct of_device_id __maybe_unused qt1050_of_match[] = {
580 { .compatible = "microchip,qt1050", },
581 { },
582};
583MODULE_DEVICE_TABLE(of, qt1050_of_match);
584
585static struct i2c_driver qt1050_driver = {
586 .driver = {
587 .name = "qt1050",
588 .of_match_table = of_match_ptr(qt1050_of_match),
589 .pm = pm_sleep_ptr(&qt1050_pm_ops),
590 },
591 .probe = qt1050_probe,
592};
593
594module_i2c_driver(qt1050_driver);
595
596MODULE_AUTHOR("Marco Felsch <kernel@pengutronix.de");
597MODULE_DESCRIPTION("Driver for AT42QT1050 QTouch sensor");
598MODULE_LICENSE("GPL v2");
599

source code of linux/drivers/input/keyboard/qt1050.c