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 <linux/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 = sysfs_emit(buf, "%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 ATTRIBUTE_GROUPS(hycon_hy46xx);
278
hycon_hy46xx_get_defaults(struct device * dev,struct hycon_hy46xx_data * tsdata)279 static void hycon_hy46xx_get_defaults(struct device *dev, struct hycon_hy46xx_data *tsdata)
280 {
281 bool val_bool;
282 int error;
283 u32 val;
284
285 error = device_property_read_u32(dev, "hycon,threshold", &val);
286 if (!error) {
287 error = regmap_write(tsdata->regmap, HY46XX_THRESHOLD, val);
288 if (error < 0)
289 goto out;
290
291 tsdata->threshold = val;
292 }
293
294 val_bool = device_property_read_bool(dev, "hycon,glove-enable");
295 error = regmap_write(tsdata->regmap, HY46XX_GLOVE_EN, val_bool);
296 if (error < 0)
297 goto out;
298 tsdata->glove_enable = val_bool;
299
300 error = device_property_read_u32(dev, "hycon,report-speed-hz", &val);
301 if (!error) {
302 error = regmap_write(tsdata->regmap, HY46XX_REPORT_SPEED, val);
303 if (error < 0)
304 goto out;
305
306 tsdata->report_speed = val;
307 }
308
309 val_bool = device_property_read_bool(dev, "hycon,noise-filter-enable");
310 error = regmap_write(tsdata->regmap, HY46XX_PWR_NOISE_EN, val_bool);
311 if (error < 0)
312 goto out;
313 tsdata->noise_filter_enable = val_bool;
314
315 error = device_property_read_u32(dev, "hycon,filter-data", &val);
316 if (!error) {
317 error = regmap_write(tsdata->regmap, HY46XX_FILTER_DATA, val);
318 if (error < 0)
319 goto out;
320
321 tsdata->filter_data = val;
322 }
323
324 error = device_property_read_u32(dev, "hycon,gain", &val);
325 if (!error) {
326 error = regmap_write(tsdata->regmap, HY46XX_GAIN, val);
327 if (error < 0)
328 goto out;
329
330 tsdata->gain = val;
331 }
332
333 error = device_property_read_u32(dev, "hycon,edge-offset", &val);
334 if (!error) {
335 error = regmap_write(tsdata->regmap, HY46XX_EDGE_OFFSET, val);
336 if (error < 0)
337 goto out;
338
339 tsdata->edge_offset = val;
340 }
341
342 return;
343 out:
344 dev_err(&tsdata->client->dev, "Failed to set default settings");
345 }
346
hycon_hy46xx_get_parameters(struct hycon_hy46xx_data * tsdata)347 static void hycon_hy46xx_get_parameters(struct hycon_hy46xx_data *tsdata)
348 {
349 int error;
350 u32 val;
351
352 error = regmap_read(tsdata->regmap, HY46XX_THRESHOLD, &val);
353 if (error < 0)
354 goto out;
355 tsdata->threshold = val;
356
357 error = regmap_read(tsdata->regmap, HY46XX_GLOVE_EN, &val);
358 if (error < 0)
359 goto out;
360 tsdata->glove_enable = val;
361
362 error = regmap_read(tsdata->regmap, HY46XX_REPORT_SPEED, &val);
363 if (error < 0)
364 goto out;
365 tsdata->report_speed = val;
366
367 error = regmap_read(tsdata->regmap, HY46XX_PWR_NOISE_EN, &val);
368 if (error < 0)
369 goto out;
370 tsdata->noise_filter_enable = val;
371
372 error = regmap_read(tsdata->regmap, HY46XX_FILTER_DATA, &val);
373 if (error < 0)
374 goto out;
375 tsdata->filter_data = val;
376
377 error = regmap_read(tsdata->regmap, HY46XX_GAIN, &val);
378 if (error < 0)
379 goto out;
380 tsdata->gain = val;
381
382 error = regmap_read(tsdata->regmap, HY46XX_EDGE_OFFSET, &val);
383 if (error < 0)
384 goto out;
385 tsdata->edge_offset = val;
386
387 error = regmap_read(tsdata->regmap, HY46XX_RX_NR_USED, &val);
388 if (error < 0)
389 goto out;
390 tsdata->rx_number_used = val;
391
392 error = regmap_read(tsdata->regmap, HY46XX_TX_NR_USED, &val);
393 if (error < 0)
394 goto out;
395 tsdata->tx_number_used = val;
396
397 error = regmap_read(tsdata->regmap, HY46XX_PWR_MODE, &val);
398 if (error < 0)
399 goto out;
400 tsdata->power_mode = val;
401
402 error = regmap_read(tsdata->regmap, HY46XX_FW_VERSION, &val);
403 if (error < 0)
404 goto out;
405 tsdata->fw_version = val;
406
407 error = regmap_read(tsdata->regmap, HY46XX_LIB_VERSION, &val);
408 if (error < 0)
409 goto out;
410 tsdata->lib_version = val;
411
412 error = regmap_read(tsdata->regmap, HY46XX_TP_INFO, &val);
413 if (error < 0)
414 goto out;
415 tsdata->tp_information = val;
416
417 error = regmap_read(tsdata->regmap, HY46XX_TP_CHIP_ID, &val);
418 if (error < 0)
419 goto out;
420 tsdata->tp_chip_id = val;
421
422 error = regmap_read(tsdata->regmap, HY46XX_BOOT_VER, &val);
423 if (error < 0)
424 goto out;
425 tsdata->bootloader_version = val;
426
427 return;
428 out:
429 dev_err(&tsdata->client->dev, "Failed to read default settings");
430 }
431
hycon_hy46xx_disable_regulator(void * arg)432 static void hycon_hy46xx_disable_regulator(void *arg)
433 {
434 struct hycon_hy46xx_data *data = arg;
435
436 regulator_disable(data->vcc);
437 }
438
hycon_hy46xx_probe(struct i2c_client * client)439 static int hycon_hy46xx_probe(struct i2c_client *client)
440 {
441 struct hycon_hy46xx_data *tsdata;
442 struct input_dev *input;
443 int error;
444
445 dev_dbg(&client->dev, "probing for HYCON HY46XX I2C\n");
446
447 tsdata = devm_kzalloc(&client->dev, sizeof(*tsdata), GFP_KERNEL);
448 if (!tsdata)
449 return -ENOMEM;
450
451 tsdata->vcc = devm_regulator_get(&client->dev, "vcc");
452 if (IS_ERR(tsdata->vcc)) {
453 error = PTR_ERR(tsdata->vcc);
454 if (error != -EPROBE_DEFER)
455 dev_err(&client->dev,
456 "failed to request regulator: %d\n", error);
457 return error;
458 }
459
460 error = regulator_enable(tsdata->vcc);
461 if (error < 0) {
462 dev_err(&client->dev, "failed to enable vcc: %d\n", error);
463 return error;
464 }
465
466 error = devm_add_action_or_reset(&client->dev,
467 hycon_hy46xx_disable_regulator,
468 tsdata);
469 if (error)
470 return error;
471
472 tsdata->reset_gpio = devm_gpiod_get_optional(&client->dev,
473 "reset", GPIOD_OUT_LOW);
474 if (IS_ERR(tsdata->reset_gpio)) {
475 error = PTR_ERR(tsdata->reset_gpio);
476 dev_err(&client->dev,
477 "Failed to request GPIO reset pin, error %d\n", error);
478 return error;
479 }
480
481 if (tsdata->reset_gpio) {
482 usleep_range(5000, 6000);
483 gpiod_set_value_cansleep(tsdata->reset_gpio, 1);
484 usleep_range(5000, 6000);
485 gpiod_set_value_cansleep(tsdata->reset_gpio, 0);
486 msleep(1000);
487 }
488
489 input = devm_input_allocate_device(&client->dev);
490 if (!input) {
491 dev_err(&client->dev, "failed to allocate input device.\n");
492 return -ENOMEM;
493 }
494
495 mutex_init(&tsdata->mutex);
496 tsdata->client = client;
497 tsdata->input = input;
498
499 tsdata->regmap = devm_regmap_init_i2c(client,
500 &hycon_hy46xx_i2c_regmap_config);
501 if (IS_ERR(tsdata->regmap)) {
502 dev_err(&client->dev, "regmap allocation failed\n");
503 return PTR_ERR(tsdata->regmap);
504 }
505
506 hycon_hy46xx_get_defaults(&client->dev, tsdata);
507 hycon_hy46xx_get_parameters(tsdata);
508
509 input->name = "Hycon Capacitive Touch";
510 input->id.bustype = BUS_I2C;
511 input->dev.parent = &client->dev;
512
513 input_set_abs_params(input, ABS_MT_POSITION_X, 0, -1, 0, 0);
514 input_set_abs_params(input, ABS_MT_POSITION_Y, 0, -1, 0, 0);
515
516 touchscreen_parse_properties(input, true, &tsdata->prop);
517
518 error = input_mt_init_slots(input, HY46XX_MAX_SUPPORTED_POINTS,
519 INPUT_MT_DIRECT);
520 if (error) {
521 dev_err(&client->dev, "Unable to init MT slots.\n");
522 return error;
523 }
524
525 i2c_set_clientdata(client, tsdata);
526
527 error = devm_request_threaded_irq(&client->dev, client->irq,
528 NULL, hycon_hy46xx_isr, IRQF_ONESHOT,
529 client->name, tsdata);
530 if (error) {
531 dev_err(&client->dev, "Unable to request touchscreen IRQ.\n");
532 return error;
533 }
534
535 error = input_register_device(input);
536 if (error)
537 return error;
538
539 dev_dbg(&client->dev,
540 "HYCON HY46XX initialized: IRQ %d, Reset pin %d.\n",
541 client->irq,
542 tsdata->reset_gpio ? desc_to_gpio(tsdata->reset_gpio) : -1);
543
544 return 0;
545 }
546
547 static const struct i2c_device_id hycon_hy46xx_id[] = {
548 { .name = "hy4613" },
549 { .name = "hy4614" },
550 { .name = "hy4621" },
551 { .name = "hy4623" },
552 { .name = "hy4633" },
553 { .name = "hy4635" },
554 { /* sentinel */ }
555 };
556 MODULE_DEVICE_TABLE(i2c, hycon_hy46xx_id);
557
558 static const struct of_device_id hycon_hy46xx_of_match[] = {
559 { .compatible = "hycon,hy4613" },
560 { .compatible = "hycon,hy4614" },
561 { .compatible = "hycon,hy4621" },
562 { .compatible = "hycon,hy4623" },
563 { .compatible = "hycon,hy4633" },
564 { .compatible = "hycon,hy4635" },
565 { /* sentinel */ }
566 };
567 MODULE_DEVICE_TABLE(of, hycon_hy46xx_of_match);
568
569 static struct i2c_driver hycon_hy46xx_driver = {
570 .driver = {
571 .name = "hycon_hy46xx",
572 .dev_groups = hycon_hy46xx_groups,
573 .of_match_table = hycon_hy46xx_of_match,
574 .probe_type = PROBE_PREFER_ASYNCHRONOUS,
575 },
576 .id_table = hycon_hy46xx_id,
577 .probe = hycon_hy46xx_probe,
578 };
579
580 module_i2c_driver(hycon_hy46xx_driver);
581
582 MODULE_AUTHOR("Giulio Benetti <giulio.benetti@benettiengineering.com>");
583 MODULE_DESCRIPTION("HYCON HY46XX I2C Touchscreen Driver");
584 MODULE_LICENSE("GPL v2");
585