1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Copyright (C) 2021
4 * Author(s): Giulio Benetti <giulio.benetti@benettiengineering.com>
5 */
6
7 #include <linux/delay.h>
8 #include <linux/gpio/consumer.h>
9 #include <linux/i2c.h>
10 #include <linux/interrupt.h>
11 #include <linux/input.h>
12 #include <linux/input/mt.h>
13 #include <linux/input/touchscreen.h>
14 #include <linux/irq.h>
15 #include <linux/regulator/consumer.h>
16 #include <linux/regmap.h>
17
18 #include <asm/unaligned.h>
19
20 #define HY46XX_CHKSUM_CODE 0x1
21 #define HY46XX_FINGER_NUM 0x2
22 #define HY46XX_CHKSUM_LEN 0x7
23 #define HY46XX_THRESHOLD 0x80
24 #define HY46XX_GLOVE_EN 0x84
25 #define HY46XX_REPORT_SPEED 0x88
26 #define HY46XX_PWR_NOISE_EN 0x89
27 #define HY46XX_FILTER_DATA 0x8A
28 #define HY46XX_GAIN 0x92
29 #define HY46XX_EDGE_OFFSET 0x93
30 #define HY46XX_RX_NR_USED 0x94
31 #define HY46XX_TX_NR_USED 0x95
32 #define HY46XX_PWR_MODE 0xA5
33 #define HY46XX_FW_VERSION 0xA6
34 #define HY46XX_LIB_VERSION 0xA7
35 #define HY46XX_TP_INFO 0xA8
36 #define HY46XX_TP_CHIP_ID 0xA9
37 #define HY46XX_BOOT_VER 0xB0
38
39 #define HY46XX_TPLEN 0x6
40 #define HY46XX_REPORT_PKT_LEN 0x44
41
42 #define HY46XX_MAX_SUPPORTED_POINTS 11
43
44 #define TOUCH_EVENT_DOWN 0x00
45 #define TOUCH_EVENT_UP 0x01
46 #define TOUCH_EVENT_CONTACT 0x02
47 #define TOUCH_EVENT_RESERVED 0x03
48
49 struct hycon_hy46xx_data {
50 struct i2c_client *client;
51 struct input_dev *input;
52 struct touchscreen_properties prop;
53 struct regulator *vcc;
54
55 struct gpio_desc *reset_gpio;
56
57 struct mutex mutex;
58 struct regmap *regmap;
59
60 int threshold;
61 bool glove_enable;
62 int report_speed;
63 bool noise_filter_enable;
64 int filter_data;
65 int gain;
66 int edge_offset;
67 int rx_number_used;
68 int tx_number_used;
69 int power_mode;
70 int fw_version;
71 int lib_version;
72 int tp_information;
73 int tp_chip_id;
74 int bootloader_version;
75 };
76
77 static const struct regmap_config hycon_hy46xx_i2c_regmap_config = {
78 .reg_bits = 8,
79 .val_bits = 8,
80 };
81
hycon_hy46xx_check_checksum(struct hycon_hy46xx_data * tsdata,u8 * buf)82 static bool hycon_hy46xx_check_checksum(struct hycon_hy46xx_data *tsdata, u8 *buf)
83 {
84 u8 chksum = 0;
85 int i;
86
87 for (i = 2; i < buf[HY46XX_CHKSUM_LEN]; i++)
88 chksum += buf[i];
89
90 if (chksum == buf[HY46XX_CHKSUM_CODE])
91 return true;
92
93 dev_err_ratelimited(&tsdata->client->dev,
94 "checksum error: 0x%02x expected, got 0x%02x\n",
95 chksum, buf[HY46XX_CHKSUM_CODE]);
96
97 return false;
98 }
99
hycon_hy46xx_isr(int irq,void * dev_id)100 static irqreturn_t hycon_hy46xx_isr(int irq, void *dev_id)
101 {
102 struct hycon_hy46xx_data *tsdata = dev_id;
103 struct device *dev = &tsdata->client->dev;
104 u8 rdbuf[HY46XX_REPORT_PKT_LEN];
105 int i, x, y, id;
106 int error;
107
108 memset(rdbuf, 0, sizeof(rdbuf));
109
110 error = regmap_bulk_read(tsdata->regmap, 0, rdbuf, sizeof(rdbuf));
111 if (error) {
112 dev_err_ratelimited(dev, "Unable to fetch data, error: %d\n",
113 error);
114 goto out;
115 }
116
117 if (!hycon_hy46xx_check_checksum(tsdata, rdbuf))
118 goto out;
119
120 for (i = 0; i < HY46XX_MAX_SUPPORTED_POINTS; i++) {
121 u8 *buf = &rdbuf[3 + (HY46XX_TPLEN * i)];
122 int type = buf[0] >> 6;
123
124 if (type == TOUCH_EVENT_RESERVED)
125 continue;
126
127 x = get_unaligned_be16(buf) & 0x0fff;
128 y = get_unaligned_be16(buf + 2) & 0x0fff;
129
130 id = buf[2] >> 4;
131
132 input_mt_slot(tsdata->input, id);
133 if (input_mt_report_slot_state(tsdata->input, MT_TOOL_FINGER,
134 type != TOUCH_EVENT_UP))
135 touchscreen_report_pos(tsdata->input, &tsdata->prop,
136 x, y, true);
137 }
138
139 input_mt_report_pointer_emulation(tsdata->input, false);
140 input_sync(tsdata->input);
141
142 out:
143 return IRQ_HANDLED;
144 }
145
146 struct hycon_hy46xx_attribute {
147 struct device_attribute dattr;
148 size_t field_offset;
149 u8 address;
150 u8 limit_low;
151 u8 limit_high;
152 };
153
154 #define HYCON_ATTR_U8(_field, _mode, _address, _limit_low, _limit_high) \
155 struct hycon_hy46xx_attribute hycon_hy46xx_attr_##_field = { \
156 .dattr = __ATTR(_field, _mode, \
157 hycon_hy46xx_setting_show, \
158 hycon_hy46xx_setting_store), \
159 .field_offset = offsetof(struct hycon_hy46xx_data, _field), \
160 .address = _address, \
161 .limit_low = _limit_low, \
162 .limit_high = _limit_high, \
163 }
164
165 #define HYCON_ATTR_BOOL(_field, _mode, _address) \
166 struct hycon_hy46xx_attribute hycon_hy46xx_attr_##_field = { \
167 .dattr = __ATTR(_field, _mode, \
168 hycon_hy46xx_setting_show, \
169 hycon_hy46xx_setting_store), \
170 .field_offset = offsetof(struct hycon_hy46xx_data, _field), \
171 .address = _address, \
172 .limit_low = false, \
173 .limit_high = true, \
174 }
175
hycon_hy46xx_setting_show(struct device * dev,struct device_attribute * dattr,char * buf)176 static ssize_t hycon_hy46xx_setting_show(struct device *dev,
177 struct device_attribute *dattr, char *buf)
178 {
179 struct i2c_client *client = to_i2c_client(dev);
180 struct hycon_hy46xx_data *tsdata = i2c_get_clientdata(client);
181 struct hycon_hy46xx_attribute *attr =
182 container_of(dattr, struct hycon_hy46xx_attribute, dattr);
183 u8 *field = (u8 *)tsdata + attr->field_offset;
184 size_t count = 0;
185 int error = 0;
186 int val;
187
188 mutex_lock(&tsdata->mutex);
189
190 error = regmap_read(tsdata->regmap, attr->address, &val);
191 if (error < 0) {
192 dev_err(&tsdata->client->dev,
193 "Failed to fetch attribute %s, error %d\n",
194 dattr->attr.name, error);
195 goto out;
196 }
197
198 if (val != *field) {
199 dev_warn(&tsdata->client->dev,
200 "%s: read (%d) and stored value (%d) differ\n",
201 dattr->attr.name, val, *field);
202 *field = val;
203 }
204
205 count = scnprintf(buf, PAGE_SIZE, "%d\n", val);
206
207 out:
208 mutex_unlock(&tsdata->mutex);
209 return error ?: count;
210 }
211
hycon_hy46xx_setting_store(struct device * dev,struct device_attribute * dattr,const char * buf,size_t count)212 static ssize_t hycon_hy46xx_setting_store(struct device *dev,
213 struct device_attribute *dattr,
214 const char *buf, size_t count)
215 {
216 struct i2c_client *client = to_i2c_client(dev);
217 struct hycon_hy46xx_data *tsdata = i2c_get_clientdata(client);
218 struct hycon_hy46xx_attribute *attr =
219 container_of(dattr, struct hycon_hy46xx_attribute, dattr);
220 u8 *field = (u8 *)tsdata + attr->field_offset;
221 unsigned int val;
222 int error;
223
224 mutex_lock(&tsdata->mutex);
225
226 error = kstrtouint(buf, 0, &val);
227 if (error)
228 goto out;
229
230 if (val < attr->limit_low || val > attr->limit_high) {
231 error = -ERANGE;
232 goto out;
233 }
234
235 error = regmap_write(tsdata->regmap, attr->address, val);
236 if (error < 0) {
237 dev_err(&tsdata->client->dev,
238 "Failed to update attribute %s, error: %d\n",
239 dattr->attr.name, error);
240 goto out;
241 }
242 *field = val;
243
244 out:
245 mutex_unlock(&tsdata->mutex);
246 return error ?: count;
247 }
248
249 static HYCON_ATTR_U8(threshold, 0644, HY46XX_THRESHOLD, 0, 255);
250 static HYCON_ATTR_BOOL(glove_enable, 0644, HY46XX_GLOVE_EN);
251 static HYCON_ATTR_U8(report_speed, 0644, HY46XX_REPORT_SPEED, 0, 255);
252 static HYCON_ATTR_BOOL(noise_filter_enable, 0644, HY46XX_PWR_NOISE_EN);
253 static HYCON_ATTR_U8(filter_data, 0644, HY46XX_FILTER_DATA, 0, 5);
254 static HYCON_ATTR_U8(gain, 0644, HY46XX_GAIN, 0, 5);
255 static HYCON_ATTR_U8(edge_offset, 0644, HY46XX_EDGE_OFFSET, 0, 5);
256 static HYCON_ATTR_U8(fw_version, 0444, HY46XX_FW_VERSION, 0, 255);
257 static HYCON_ATTR_U8(lib_version, 0444, HY46XX_LIB_VERSION, 0, 255);
258 static HYCON_ATTR_U8(tp_information, 0444, HY46XX_TP_INFO, 0, 255);
259 static HYCON_ATTR_U8(tp_chip_id, 0444, HY46XX_TP_CHIP_ID, 0, 255);
260 static HYCON_ATTR_U8(bootloader_version, 0444, HY46XX_BOOT_VER, 0, 255);
261
262 static struct attribute *hycon_hy46xx_attrs[] = {
263 &hycon_hy46xx_attr_threshold.dattr.attr,
264 &hycon_hy46xx_attr_glove_enable.dattr.attr,
265 &hycon_hy46xx_attr_report_speed.dattr.attr,
266 &hycon_hy46xx_attr_noise_filter_enable.dattr.attr,
267 &hycon_hy46xx_attr_filter_data.dattr.attr,
268 &hycon_hy46xx_attr_gain.dattr.attr,
269 &hycon_hy46xx_attr_edge_offset.dattr.attr,
270 &hycon_hy46xx_attr_fw_version.dattr.attr,
271 &hycon_hy46xx_attr_lib_version.dattr.attr,
272 &hycon_hy46xx_attr_tp_information.dattr.attr,
273 &hycon_hy46xx_attr_tp_chip_id.dattr.attr,
274 &hycon_hy46xx_attr_bootloader_version.dattr.attr,
275 NULL
276 };
277
278 static const struct attribute_group hycon_hy46xx_attr_group = {
279 .attrs = hycon_hy46xx_attrs,
280 };
281
hycon_hy46xx_get_defaults(struct device * dev,struct hycon_hy46xx_data * tsdata)282 static void hycon_hy46xx_get_defaults(struct device *dev, struct hycon_hy46xx_data *tsdata)
283 {
284 bool val_bool;
285 int error;
286 u32 val;
287
288 error = device_property_read_u32(dev, "hycon,threshold", &val);
289 if (!error) {
290 error = regmap_write(tsdata->regmap, HY46XX_THRESHOLD, val);
291 if (error < 0)
292 goto out;
293
294 tsdata->threshold = val;
295 }
296
297 val_bool = device_property_read_bool(dev, "hycon,glove-enable");
298 error = regmap_write(tsdata->regmap, HY46XX_GLOVE_EN, val_bool);
299 if (error < 0)
300 goto out;
301 tsdata->glove_enable = val_bool;
302
303 error = device_property_read_u32(dev, "hycon,report-speed-hz", &val);
304 if (!error) {
305 error = regmap_write(tsdata->regmap, HY46XX_REPORT_SPEED, val);
306 if (error < 0)
307 goto out;
308
309 tsdata->report_speed = val;
310 }
311
312 val_bool = device_property_read_bool(dev, "hycon,noise-filter-enable");
313 error = regmap_write(tsdata->regmap, HY46XX_PWR_NOISE_EN, val_bool);
314 if (error < 0)
315 goto out;
316 tsdata->noise_filter_enable = val_bool;
317
318 error = device_property_read_u32(dev, "hycon,filter-data", &val);
319 if (!error) {
320 error = regmap_write(tsdata->regmap, HY46XX_FILTER_DATA, val);
321 if (error < 0)
322 goto out;
323
324 tsdata->filter_data = val;
325 }
326
327 error = device_property_read_u32(dev, "hycon,gain", &val);
328 if (!error) {
329 error = regmap_write(tsdata->regmap, HY46XX_GAIN, val);
330 if (error < 0)
331 goto out;
332
333 tsdata->gain = val;
334 }
335
336 error = device_property_read_u32(dev, "hycon,edge-offset", &val);
337 if (!error) {
338 error = regmap_write(tsdata->regmap, HY46XX_EDGE_OFFSET, val);
339 if (error < 0)
340 goto out;
341
342 tsdata->edge_offset = val;
343 }
344
345 return;
346 out:
347 dev_err(&tsdata->client->dev, "Failed to set default settings");
348 }
349
hycon_hy46xx_get_parameters(struct hycon_hy46xx_data * tsdata)350 static void hycon_hy46xx_get_parameters(struct hycon_hy46xx_data *tsdata)
351 {
352 int error;
353 u32 val;
354
355 error = regmap_read(tsdata->regmap, HY46XX_THRESHOLD, &val);
356 if (error < 0)
357 goto out;
358 tsdata->threshold = val;
359
360 error = regmap_read(tsdata->regmap, HY46XX_GLOVE_EN, &val);
361 if (error < 0)
362 goto out;
363 tsdata->glove_enable = val;
364
365 error = regmap_read(tsdata->regmap, HY46XX_REPORT_SPEED, &val);
366 if (error < 0)
367 goto out;
368 tsdata->report_speed = val;
369
370 error = regmap_read(tsdata->regmap, HY46XX_PWR_NOISE_EN, &val);
371 if (error < 0)
372 goto out;
373 tsdata->noise_filter_enable = val;
374
375 error = regmap_read(tsdata->regmap, HY46XX_FILTER_DATA, &val);
376 if (error < 0)
377 goto out;
378 tsdata->filter_data = val;
379
380 error = regmap_read(tsdata->regmap, HY46XX_GAIN, &val);
381 if (error < 0)
382 goto out;
383 tsdata->gain = val;
384
385 error = regmap_read(tsdata->regmap, HY46XX_EDGE_OFFSET, &val);
386 if (error < 0)
387 goto out;
388 tsdata->edge_offset = val;
389
390 error = regmap_read(tsdata->regmap, HY46XX_RX_NR_USED, &val);
391 if (error < 0)
392 goto out;
393 tsdata->rx_number_used = val;
394
395 error = regmap_read(tsdata->regmap, HY46XX_TX_NR_USED, &val);
396 if (error < 0)
397 goto out;
398 tsdata->tx_number_used = val;
399
400 error = regmap_read(tsdata->regmap, HY46XX_PWR_MODE, &val);
401 if (error < 0)
402 goto out;
403 tsdata->power_mode = val;
404
405 error = regmap_read(tsdata->regmap, HY46XX_FW_VERSION, &val);
406 if (error < 0)
407 goto out;
408 tsdata->fw_version = val;
409
410 error = regmap_read(tsdata->regmap, HY46XX_LIB_VERSION, &val);
411 if (error < 0)
412 goto out;
413 tsdata->lib_version = val;
414
415 error = regmap_read(tsdata->regmap, HY46XX_TP_INFO, &val);
416 if (error < 0)
417 goto out;
418 tsdata->tp_information = val;
419
420 error = regmap_read(tsdata->regmap, HY46XX_TP_CHIP_ID, &val);
421 if (error < 0)
422 goto out;
423 tsdata->tp_chip_id = val;
424
425 error = regmap_read(tsdata->regmap, HY46XX_BOOT_VER, &val);
426 if (error < 0)
427 goto out;
428 tsdata->bootloader_version = val;
429
430 return;
431 out:
432 dev_err(&tsdata->client->dev, "Failed to read default settings");
433 }
434
hycon_hy46xx_disable_regulator(void * arg)435 static void hycon_hy46xx_disable_regulator(void *arg)
436 {
437 struct hycon_hy46xx_data *data = arg;
438
439 regulator_disable(data->vcc);
440 }
441
hycon_hy46xx_probe(struct i2c_client * client)442 static int hycon_hy46xx_probe(struct i2c_client *client)
443 {
444 struct hycon_hy46xx_data *tsdata;
445 struct input_dev *input;
446 int error;
447
448 dev_dbg(&client->dev, "probing for HYCON HY46XX I2C\n");
449
450 tsdata = devm_kzalloc(&client->dev, sizeof(*tsdata), GFP_KERNEL);
451 if (!tsdata)
452 return -ENOMEM;
453
454 tsdata->vcc = devm_regulator_get(&client->dev, "vcc");
455 if (IS_ERR(tsdata->vcc)) {
456 error = PTR_ERR(tsdata->vcc);
457 if (error != -EPROBE_DEFER)
458 dev_err(&client->dev,
459 "failed to request regulator: %d\n", error);
460 return error;
461 }
462
463 error = regulator_enable(tsdata->vcc);
464 if (error < 0) {
465 dev_err(&client->dev, "failed to enable vcc: %d\n", error);
466 return error;
467 }
468
469 error = devm_add_action_or_reset(&client->dev,
470 hycon_hy46xx_disable_regulator,
471 tsdata);
472 if (error)
473 return error;
474
475 tsdata->reset_gpio = devm_gpiod_get_optional(&client->dev,
476 "reset", GPIOD_OUT_LOW);
477 if (IS_ERR(tsdata->reset_gpio)) {
478 error = PTR_ERR(tsdata->reset_gpio);
479 dev_err(&client->dev,
480 "Failed to request GPIO reset pin, error %d\n", error);
481 return error;
482 }
483
484 if (tsdata->reset_gpio) {
485 usleep_range(5000, 6000);
486 gpiod_set_value_cansleep(tsdata->reset_gpio, 1);
487 usleep_range(5000, 6000);
488 gpiod_set_value_cansleep(tsdata->reset_gpio, 0);
489 msleep(1000);
490 }
491
492 input = devm_input_allocate_device(&client->dev);
493 if (!input) {
494 dev_err(&client->dev, "failed to allocate input device.\n");
495 return -ENOMEM;
496 }
497
498 mutex_init(&tsdata->mutex);
499 tsdata->client = client;
500 tsdata->input = input;
501
502 tsdata->regmap = devm_regmap_init_i2c(client,
503 &hycon_hy46xx_i2c_regmap_config);
504 if (IS_ERR(tsdata->regmap)) {
505 dev_err(&client->dev, "regmap allocation failed\n");
506 return PTR_ERR(tsdata->regmap);
507 }
508
509 hycon_hy46xx_get_defaults(&client->dev, tsdata);
510 hycon_hy46xx_get_parameters(tsdata);
511
512 input->name = "Hycon Capacitive Touch";
513 input->id.bustype = BUS_I2C;
514 input->dev.parent = &client->dev;
515
516 input_set_abs_params(input, ABS_MT_POSITION_X, 0, -1, 0, 0);
517 input_set_abs_params(input, ABS_MT_POSITION_Y, 0, -1, 0, 0);
518
519 touchscreen_parse_properties(input, true, &tsdata->prop);
520
521 error = input_mt_init_slots(input, HY46XX_MAX_SUPPORTED_POINTS,
522 INPUT_MT_DIRECT);
523 if (error) {
524 dev_err(&client->dev, "Unable to init MT slots.\n");
525 return error;
526 }
527
528 i2c_set_clientdata(client, tsdata);
529
530 error = devm_request_threaded_irq(&client->dev, client->irq,
531 NULL, hycon_hy46xx_isr, IRQF_ONESHOT,
532 client->name, tsdata);
533 if (error) {
534 dev_err(&client->dev, "Unable to request touchscreen IRQ.\n");
535 return error;
536 }
537
538 error = devm_device_add_group(&client->dev, &hycon_hy46xx_attr_group);
539 if (error)
540 return error;
541
542 error = input_register_device(input);
543 if (error)
544 return error;
545
546 dev_dbg(&client->dev,
547 "HYCON HY46XX initialized: IRQ %d, Reset pin %d.\n",
548 client->irq,
549 tsdata->reset_gpio ? desc_to_gpio(tsdata->reset_gpio) : -1);
550
551 return 0;
552 }
553
554 static const struct i2c_device_id hycon_hy46xx_id[] = {
555 { .name = "hy4613" },
556 { .name = "hy4614" },
557 { .name = "hy4621" },
558 { .name = "hy4623" },
559 { .name = "hy4633" },
560 { .name = "hy4635" },
561 { /* sentinel */ }
562 };
563 MODULE_DEVICE_TABLE(i2c, hycon_hy46xx_id);
564
565 static const struct of_device_id hycon_hy46xx_of_match[] = {
566 { .compatible = "hycon,hy4613" },
567 { .compatible = "hycon,hy4614" },
568 { .compatible = "hycon,hy4621" },
569 { .compatible = "hycon,hy4623" },
570 { .compatible = "hycon,hy4633" },
571 { .compatible = "hycon,hy4635" },
572 { /* sentinel */ }
573 };
574 MODULE_DEVICE_TABLE(of, hycon_hy46xx_of_match);
575
576 static struct i2c_driver hycon_hy46xx_driver = {
577 .driver = {
578 .name = "hycon_hy46xx",
579 .of_match_table = hycon_hy46xx_of_match,
580 .probe_type = PROBE_PREFER_ASYNCHRONOUS,
581 },
582 .id_table = hycon_hy46xx_id,
583 .probe = hycon_hy46xx_probe,
584 };
585
586 module_i2c_driver(hycon_hy46xx_driver);
587
588 MODULE_AUTHOR("Giulio Benetti <giulio.benetti@benettiengineering.com>");
589 MODULE_DESCRIPTION("HYCON HY46XX I2C Touchscreen Driver");
590 MODULE_LICENSE("GPL v2");
591
