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
98 struct qt1050_key_regs {
99 unsigned int nthr;
100 unsigned int pulse_scale;
101 unsigned int di_aks;
102 unsigned int csd;
103 };
104
105 struct qt1050_key {
106 u32 num;
107 u32 charge_delay;
108 u32 thr_cnt;
109 u32 samples;
110 u32 scale;
111 u32 keycode;
112 };
113
114 struct 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
124 static 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
qt1050_volatile_reg(struct device * dev,unsigned int reg)153 static 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
174 static 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
190 static 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
195 static 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
206 static 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
211 static 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_RBTREE,
217
218 .wr_table = &qt1050_writeable_table,
219 .rd_table = &qt1050_readable_table,
220 .volatile_reg = qt1050_volatile_reg,
221 };
222
qt1050_identify(struct qt1050_priv * ts)223 static bool qt1050_identify(struct qt1050_priv *ts)
224 {
225 unsigned int val;
226 int err;
227
228 /* Read Chip ID */
229 err = regmap_read(ts->regmap, QT1050_CHIP_ID, &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(ts->regmap, QT1050_FW_VERSION, &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
qt1050_irq_threaded(int irq,void * dev_id)253 static 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(ts->regmap, QT1050_DET_STATUS, &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(ts->regmap, QT1050_KEY_STATUS, &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(input, ts->keys[i].keycode,
283 test_bit(i, &new_keys));
284
285 ts->last_keys = new_keys;
286 input_sync(input);
287
288 return IRQ_HANDLED;
289 }
290
qt1050_get_key_regs(int key_num)291 static const struct qt1050_key_regs *qt1050_get_key_regs(int key_num)
292 {
293 return &qt1050_key_regs_data[key_num];
294 }
295
qt1050_set_key(struct regmap * map,int number,int on)296 static 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(number);
301
302 return regmap_update_bits(map, key_regs->di_aks, 0xfc,
303 on ? BIT(4) : 0x00);
304 }
305
qt1050_apply_fw_data(struct qt1050_priv * ts)306 static 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, i, 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, button->num, 1);
326 if (err)
327 return err;
328
329 key_regs = qt1050_get_key_regs(button->num);
330
331 err = regmap_write(map, key_regs->pulse_scale,
332 (button->samples << 4) | (button->scale));
333 if (err)
334 return err;
335 err = regmap_write(map, key_regs->csd, button->charge_delay);
336 if (err)
337 return err;
338 err = regmap_write(map, key_regs->nthr, button->thr_cnt);
339 if (err)
340 return err;
341 }
342
343 return 0;
344 }
345
qt1050_parse_fw(struct qt1050_priv * ts)346 static int qt1050_parse_fw(struct qt1050_priv *ts)
347 {
348 struct device *dev = &ts->client->dev;
349 struct fwnode_handle *child;
350 int nbuttons;
351
352 nbuttons = device_get_child_node_count(dev);
353 if (nbuttons == 0 || nbuttons > QT1050_MAX_KEYS)
354 return -ENODEV;
355
356 device_for_each_child_node(dev, child) {
357 struct qt1050_key button;
358
359 /* Required properties */
360 if (fwnode_property_read_u32(child, "linux,code",
361 &button.keycode)) {
362 dev_err(dev, "Button without keycode\n");
363 goto err;
364 }
365 if (button.keycode >= KEY_MAX) {
366 dev_err(dev, "Invalid keycode 0x%x\n",
367 button.keycode);
368 goto err;
369 }
370
371 if (fwnode_property_read_u32(child, "reg",
372 &button.num)) {
373 dev_err(dev, "Button without pad number\n");
374 goto err;
375 }
376 if (button.num < 0 || button.num > QT1050_MAX_KEYS - 1)
377 goto err;
378
379 ts->reg_keys |= BIT(button.num);
380
381 /* Optional properties */
382 if (fwnode_property_read_u32(child,
383 "microchip,pre-charge-time-ns",
384 &button.charge_delay)) {
385 button.charge_delay = 0;
386 } else {
387 if (button.charge_delay % 2500 == 0)
388 button.charge_delay =
389 button.charge_delay / 2500;
390 else
391 button.charge_delay = 0;
392 }
393
394 if (fwnode_property_read_u32(child, "microchip,average-samples",
395 &button.samples)) {
396 button.samples = 0;
397 } else {
398 if (is_power_of_2(button.samples))
399 button.samples = ilog2(button.samples);
400 else
401 button.samples = 0;
402 }
403
404 if (fwnode_property_read_u32(child, "microchip,average-scaling",
405 &button.scale)) {
406 button.scale = 0;
407 } else {
408 if (is_power_of_2(button.scale))
409 button.scale = ilog2(button.scale);
410 else
411 button.scale = 0;
412
413 }
414
415 if (fwnode_property_read_u32(child, "microchip,threshold",
416 &button.thr_cnt)) {
417 button.thr_cnt = 20;
418 } else {
419 if (button.thr_cnt > 255)
420 button.thr_cnt = 20;
421 }
422
423 ts->keys[button.num] = button;
424 }
425
426 return 0;
427
428 err:
429 fwnode_handle_put(child);
430 return -EINVAL;
431 }
432
qt1050_probe(struct i2c_client * client)433 static int qt1050_probe(struct i2c_client *client)
434 {
435 struct qt1050_priv *ts;
436 struct input_dev *input;
437 struct device *dev = &client->dev;
438 struct regmap *map;
439 unsigned int status, i;
440 int err;
441
442 /* Check basic functionality */
443 err = i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE);
444 if (!err) {
445 dev_err(&client->dev, "%s adapter not supported\n",
446 dev_driver_string(&client->adapter->dev));
447 return -ENODEV;
448 }
449
450 if (!client->irq) {
451 dev_err(dev, "assign a irq line to this device\n");
452 return -EINVAL;
453 }
454
455 ts = devm_kzalloc(dev, sizeof(*ts), GFP_KERNEL);
456 if (!ts)
457 return -ENOMEM;
458
459 input = devm_input_allocate_device(dev);
460 if (!input)
461 return -ENOMEM;
462
463 map = devm_regmap_init_i2c(client, &qt1050_regmap_config);
464 if (IS_ERR(map))
465 return PTR_ERR(map);
466
467 ts->client = client;
468 ts->input = input;
469 ts->regmap = map;
470
471 i2c_set_clientdata(client, ts);
472
473 /* Identify the qt1050 chip */
474 if (!qt1050_identify(ts))
475 return -ENODEV;
476
477 /* Get pdata */
478 err = qt1050_parse_fw(ts);
479 if (err) {
480 dev_err(dev, "Failed to parse firmware: %d\n", err);
481 return err;
482 }
483
484 input->name = "AT42QT1050 QTouch Sensor";
485 input->dev.parent = &client->dev;
486 input->id.bustype = BUS_I2C;
487
488 /* Add the keycode */
489 input->keycode = ts->keycodes;
490 input->keycodesize = sizeof(ts->keycodes[0]);
491 input->keycodemax = QT1050_MAX_KEYS;
492
493 __set_bit(EV_KEY, input->evbit);
494 for (i = 0; i < QT1050_MAX_KEYS; i++) {
495 ts->keycodes[i] = ts->keys[i].keycode;
496 __set_bit(ts->keycodes[i], input->keybit);
497 }
498
499 /* Trigger re-calibration */
500 err = regmap_update_bits(ts->regmap, QT1050_RES_CAL, 0x7f,
501 QT1050_RES_CAL_CALIBRATE);
502 if (err) {
503 dev_err(dev, "Trigger calibration failed: %d\n", err);
504 return err;
505 }
506 err = regmap_read_poll_timeout(ts->regmap, QT1050_DET_STATUS, status,
507 status >> 7 == 1, 10000, 200000);
508 if (err) {
509 dev_err(dev, "Calibration failed: %d\n", err);
510 return err;
511 }
512
513 /* Soft reset to set defaults */
514 err = regmap_update_bits(ts->regmap, QT1050_RES_CAL,
515 QT1050_RES_CAL_RESET, QT1050_RES_CAL_RESET);
516 if (err) {
517 dev_err(dev, "Trigger soft reset failed: %d\n", err);
518 return err;
519 }
520 msleep(QT1050_RESET_TIME);
521
522 /* Set pdata */
523 err = qt1050_apply_fw_data(ts);
524 if (err) {
525 dev_err(dev, "Failed to set firmware data: %d\n", err);
526 return err;
527 }
528
529 err = devm_request_threaded_irq(dev, client->irq, NULL,
530 qt1050_irq_threaded, IRQF_ONESHOT,
531 "qt1050", ts);
532 if (err) {
533 dev_err(&client->dev, "Failed to request irq: %d\n", err);
534 return err;
535 }
536
537 /* Clear #CHANGE line */
538 err = regmap_read(ts->regmap, QT1050_DET_STATUS, &status);
539 if (err) {
540 dev_err(dev, "Failed to clear #CHANGE line level: %d\n", err);
541 return err;
542 }
543
544 /* Register the input device */
545 err = input_register_device(ts->input);
546 if (err) {
547 dev_err(&client->dev, "Failed to register input device: %d\n",
548 err);
549 return err;
550 }
551
552 return 0;
553 }
554
qt1050_suspend(struct device * dev)555 static int qt1050_suspend(struct device *dev)
556 {
557 struct i2c_client *client = to_i2c_client(dev);
558 struct qt1050_priv *ts = i2c_get_clientdata(client);
559
560 disable_irq(client->irq);
561
562 /*
563 * Set measurement interval to 1s (125 x 8ms) if wakeup is allowed
564 * else turn off. The 1s interval seems to be a good compromise between
565 * low power and response time.
566 */
567 return regmap_write(ts->regmap, QT1050_LPMODE,
568 device_may_wakeup(dev) ? 125 : 0);
569 }
570
qt1050_resume(struct device * dev)571 static int qt1050_resume(struct device *dev)
572 {
573 struct i2c_client *client = to_i2c_client(dev);
574 struct qt1050_priv *ts = i2c_get_clientdata(client);
575
576 enable_irq(client->irq);
577
578 /* Set measurement interval back to 16ms (2 x 8ms) */
579 return regmap_write(ts->regmap, QT1050_LPMODE, 2);
580 }
581
582 static DEFINE_SIMPLE_DEV_PM_OPS(qt1050_pm_ops, qt1050_suspend, qt1050_resume);
583
584 static const struct of_device_id __maybe_unused qt1050_of_match[] = {
585 { .compatible = "microchip,qt1050", },
586 { },
587 };
588 MODULE_DEVICE_TABLE(of, qt1050_of_match);
589
590 static struct i2c_driver qt1050_driver = {
591 .driver = {
592 .name = "qt1050",
593 .of_match_table = of_match_ptr(qt1050_of_match),
594 .pm = pm_sleep_ptr(&qt1050_pm_ops),
595 },
596 .probe = qt1050_probe,
597 };
598
599 module_i2c_driver(qt1050_driver);
600
601 MODULE_AUTHOR("Marco Felsch <kernel@pengutronix.de");
602 MODULE_DESCRIPTION("Driver for AT42QT1050 QTouch sensor");
603 MODULE_LICENSE("GPL v2");
604