1 // SPDX-License-Identifier: GPL-2.0
2 // Samsung S6SY761 Touchscreen device driver
3 //
4 // Copyright (c) 2017 Samsung Electronics Co., Ltd.
5 // Copyright (c) 2017 Andi Shyti <andi@etezian.org>
6
7 #include <asm/unaligned.h>
8 #include <linux/delay.h>
9 #include <linux/i2c.h>
10 #include <linux/input/mt.h>
11 #include <linux/input/touchscreen.h>
12 #include <linux/interrupt.h>
13 #include <linux/irq.h>
14 #include <linux/module.h>
15 #include <linux/pm_runtime.h>
16 #include <linux/regulator/consumer.h>
17
18 /* commands */
19 #define S6SY761_SENSE_ON 0x10
20 #define S6SY761_SENSE_OFF 0x11
21 #define S6SY761_TOUCH_FUNCTION 0x30 /* R/W for get/set */
22 #define S6SY761_FIRMWARE_INTEGRITY 0x21
23 #define S6SY761_PANEL_INFO 0x23
24 #define S6SY761_DEVICE_ID 0x52
25 #define S6SY761_BOOT_STATUS 0x55
26 #define S6SY761_READ_ONE_EVENT 0x60
27 #define S6SY761_READ_ALL_EVENT 0x61
28 #define S6SY761_CLEAR_EVENT_STACK 0x62
29 #define S6SY761_APPLICATION_MODE 0xe4
30
31 /* events */
32 #define S6SY761_EVENT_INFO 0x02
33 #define S6SY761_EVENT_VENDOR_INFO 0x07
34
35 /* info */
36 #define S6SY761_INFO_BOOT_COMPLETE 0x00
37
38 /* firmware status */
39 #define S6SY761_FW_OK 0x80
40
41 /*
42 * the functionalities are put as a reference
43 * as in the device I am using none of them
44 * works therefore not used in this driver yet.
45 */
46 /* touchscreen functionalities */
47 #define S6SY761_MASK_TOUCH BIT(0)
48 #define S6SY761_MASK_HOVER BIT(1)
49 #define S6SY761_MASK_COVER BIT(2)
50 #define S6SY761_MASK_GLOVE BIT(3)
51 #define S6SY761_MASK_STYLUS BIT(4)
52 #define S6SY761_MASK_PALM BIT(5)
53 #define S6SY761_MASK_WET BIT(6)
54 #define S6SY761_MASK_PROXIMITY BIT(7)
55
56 /* boot status (BS) */
57 #define S6SY761_BS_BOOT_LOADER 0x10
58 #define S6SY761_BS_APPLICATION 0x20
59
60 /* event id */
61 #define S6SY761_EVENT_ID_COORDINATE 0x00
62 #define S6SY761_EVENT_ID_STATUS 0x01
63
64 /* event register masks */
65 #define S6SY761_MASK_TOUCH_STATE 0xc0 /* byte 0 */
66 #define S6SY761_MASK_TID 0x3c
67 #define S6SY761_MASK_EID 0x03
68 #define S6SY761_MASK_X 0xf0 /* byte 3 */
69 #define S6SY761_MASK_Y 0x0f
70 #define S6SY761_MASK_Z 0x3f /* byte 6 */
71 #define S6SY761_MASK_LEFT_EVENTS 0x3f /* byte 7 */
72 #define S6SY761_MASK_TOUCH_TYPE 0xc0 /* MSB in byte 6, LSB in byte 7 */
73
74 /* event touch state values */
75 #define S6SY761_TS_NONE 0x00
76 #define S6SY761_TS_PRESS 0x01
77 #define S6SY761_TS_MOVE 0x02
78 #define S6SY761_TS_RELEASE 0x03
79
80 /* application modes */
81 #define S6SY761_APP_NORMAL 0x0
82 #define S6SY761_APP_LOW_POWER 0x1
83 #define S6SY761_APP_TEST 0x2
84 #define S6SY761_APP_FLASH 0x3
85 #define S6SY761_APP_SLEEP 0x4
86
87 #define S6SY761_EVENT_SIZE 8
88 #define S6SY761_EVENT_COUNT 32
89 #define S6SY761_DEVID_SIZE 3
90 #define S6SY761_PANEL_ID_SIZE 11
91 #define S6SY761_TS_STATUS_SIZE 5
92 #define S6SY761_MAX_FINGERS 10
93
94 #define S6SY761_DEV_NAME "s6sy761"
95
96 enum s6sy761_regulators {
97 S6SY761_REGULATOR_VDD,
98 S6SY761_REGULATOR_AVDD,
99 };
100
101 struct s6sy761_data {
102 struct i2c_client *client;
103 struct regulator_bulk_data regulators[2];
104 struct input_dev *input;
105 struct touchscreen_properties prop;
106
107 u8 data[S6SY761_EVENT_SIZE * S6SY761_EVENT_COUNT];
108
109 u16 devid;
110 u8 tx_channel;
111 };
112
113 /*
114 * We can't simply use i2c_smbus_read_i2c_block_data because we
115 * need to read more than 255 bytes
116 */
s6sy761_read_events(struct s6sy761_data * sdata,u16 n_events)117 static int s6sy761_read_events(struct s6sy761_data *sdata, u16 n_events)
118 {
119 u8 cmd = S6SY761_READ_ALL_EVENT;
120 struct i2c_msg msgs[2] = {
121 {
122 .addr = sdata->client->addr,
123 .len = 1,
124 .buf = &cmd,
125 },
126 {
127 .addr = sdata->client->addr,
128 .flags = I2C_M_RD,
129 .len = (n_events * S6SY761_EVENT_SIZE),
130 .buf = sdata->data + S6SY761_EVENT_SIZE,
131 },
132 };
133 int ret;
134
135 ret = i2c_transfer(sdata->client->adapter, msgs, ARRAY_SIZE(msgs));
136 if (ret < 0)
137 return ret;
138
139 return ret == ARRAY_SIZE(msgs) ? 0 : -EIO;
140 }
141
s6sy761_report_coordinates(struct s6sy761_data * sdata,u8 * event,u8 tid)142 static void s6sy761_report_coordinates(struct s6sy761_data *sdata,
143 u8 *event, u8 tid)
144 {
145 u8 major = event[4];
146 u8 minor = event[5];
147 u8 z = event[6] & S6SY761_MASK_Z;
148 u16 x = (event[1] << 4) | ((event[3] & S6SY761_MASK_X) >> 4);
149 u16 y = (event[2] << 4) | (event[3] & S6SY761_MASK_Y);
150
151 input_mt_slot(sdata->input, tid);
152
153 input_mt_report_slot_state(sdata->input, MT_TOOL_FINGER, true);
154 input_report_abs(sdata->input, ABS_MT_POSITION_X, x);
155 input_report_abs(sdata->input, ABS_MT_POSITION_Y, y);
156 input_report_abs(sdata->input, ABS_MT_TOUCH_MAJOR, major);
157 input_report_abs(sdata->input, ABS_MT_TOUCH_MINOR, minor);
158 input_report_abs(sdata->input, ABS_MT_PRESSURE, z);
159
160 input_sync(sdata->input);
161 }
162
s6sy761_report_release(struct s6sy761_data * sdata,u8 * event,u8 tid)163 static void s6sy761_report_release(struct s6sy761_data *sdata,
164 u8 *event, u8 tid)
165 {
166 input_mt_slot(sdata->input, tid);
167 input_mt_report_slot_state(sdata->input, MT_TOOL_FINGER, false);
168
169 input_sync(sdata->input);
170 }
171
s6sy761_handle_coordinates(struct s6sy761_data * sdata,u8 * event)172 static void s6sy761_handle_coordinates(struct s6sy761_data *sdata, u8 *event)
173 {
174 u8 tid;
175 u8 touch_state;
176
177 if (unlikely(!(event[0] & S6SY761_MASK_TID)))
178 return;
179
180 tid = ((event[0] & S6SY761_MASK_TID) >> 2) - 1;
181 touch_state = (event[0] & S6SY761_MASK_TOUCH_STATE) >> 6;
182
183 switch (touch_state) {
184
185 case S6SY761_TS_NONE:
186 break;
187 case S6SY761_TS_RELEASE:
188 s6sy761_report_release(sdata, event, tid);
189 break;
190 case S6SY761_TS_PRESS:
191 case S6SY761_TS_MOVE:
192 s6sy761_report_coordinates(sdata, event, tid);
193 break;
194 }
195 }
196
s6sy761_handle_events(struct s6sy761_data * sdata,u8 n_events)197 static void s6sy761_handle_events(struct s6sy761_data *sdata, u8 n_events)
198 {
199 int i;
200
201 for (i = 0; i < n_events; i++) {
202 u8 *event = &sdata->data[i * S6SY761_EVENT_SIZE];
203 u8 event_id = event[0] & S6SY761_MASK_EID;
204
205 if (!event[0])
206 return;
207
208 switch (event_id) {
209
210 case S6SY761_EVENT_ID_COORDINATE:
211 s6sy761_handle_coordinates(sdata, event);
212 break;
213
214 case S6SY761_EVENT_ID_STATUS:
215 break;
216
217 default:
218 break;
219 }
220 }
221 }
222
s6sy761_irq_handler(int irq,void * dev)223 static irqreturn_t s6sy761_irq_handler(int irq, void *dev)
224 {
225 struct s6sy761_data *sdata = dev;
226 int ret;
227 u8 n_events;
228
229 ret = i2c_smbus_read_i2c_block_data(sdata->client,
230 S6SY761_READ_ONE_EVENT,
231 S6SY761_EVENT_SIZE,
232 sdata->data);
233 if (ret < 0) {
234 dev_err(&sdata->client->dev, "failed to read events\n");
235 return IRQ_HANDLED;
236 }
237
238 if (!sdata->data[0])
239 return IRQ_HANDLED;
240
241 n_events = sdata->data[7] & S6SY761_MASK_LEFT_EVENTS;
242 if (unlikely(n_events > S6SY761_EVENT_COUNT - 1))
243 return IRQ_HANDLED;
244
245 if (n_events) {
246 ret = s6sy761_read_events(sdata, n_events);
247 if (ret < 0) {
248 dev_err(&sdata->client->dev, "failed to read events\n");
249 return IRQ_HANDLED;
250 }
251 }
252
253 s6sy761_handle_events(sdata, n_events + 1);
254
255 return IRQ_HANDLED;
256 }
257
s6sy761_input_open(struct input_dev * dev)258 static int s6sy761_input_open(struct input_dev *dev)
259 {
260 struct s6sy761_data *sdata = input_get_drvdata(dev);
261
262 return i2c_smbus_write_byte(sdata->client, S6SY761_SENSE_ON);
263 }
264
s6sy761_input_close(struct input_dev * dev)265 static void s6sy761_input_close(struct input_dev *dev)
266 {
267 struct s6sy761_data *sdata = input_get_drvdata(dev);
268 int ret;
269
270 ret = i2c_smbus_write_byte(sdata->client, S6SY761_SENSE_OFF);
271 if (ret)
272 dev_err(&sdata->client->dev, "failed to turn off sensing\n");
273 }
274
s6sy761_sysfs_devid(struct device * dev,struct device_attribute * attr,char * buf)275 static ssize_t s6sy761_sysfs_devid(struct device *dev,
276 struct device_attribute *attr, char *buf)
277 {
278 struct s6sy761_data *sdata = dev_get_drvdata(dev);
279
280 return sprintf(buf, "%#x\n", sdata->devid);
281 }
282
283 static DEVICE_ATTR(devid, 0444, s6sy761_sysfs_devid, NULL);
284
285 static struct attribute *s6sy761_sysfs_attrs[] = {
286 &dev_attr_devid.attr,
287 NULL
288 };
289
290 static struct attribute_group s6sy761_attribute_group = {
291 .attrs = s6sy761_sysfs_attrs
292 };
293
s6sy761_power_on(struct s6sy761_data * sdata)294 static int s6sy761_power_on(struct s6sy761_data *sdata)
295 {
296 u8 buffer[S6SY761_EVENT_SIZE];
297 u8 event;
298 int ret;
299
300 ret = regulator_bulk_enable(ARRAY_SIZE(sdata->regulators),
301 sdata->regulators);
302 if (ret)
303 return ret;
304
305 msleep(140);
306
307 /* double check whether the touch is functional */
308 ret = i2c_smbus_read_i2c_block_data(sdata->client,
309 S6SY761_READ_ONE_EVENT,
310 S6SY761_EVENT_SIZE,
311 buffer);
312 if (ret < 0)
313 return ret;
314
315 event = (buffer[0] >> 2) & 0xf;
316
317 if ((event != S6SY761_EVENT_INFO &&
318 event != S6SY761_EVENT_VENDOR_INFO) ||
319 buffer[1] != S6SY761_INFO_BOOT_COMPLETE) {
320 return -ENODEV;
321 }
322
323 ret = i2c_smbus_read_byte_data(sdata->client, S6SY761_BOOT_STATUS);
324 if (ret < 0)
325 return ret;
326
327 /* for some reasons the device might be stuck in the bootloader */
328 if (ret != S6SY761_BS_APPLICATION)
329 return -ENODEV;
330
331 /* enable touch functionality */
332 ret = i2c_smbus_write_word_data(sdata->client,
333 S6SY761_TOUCH_FUNCTION,
334 S6SY761_MASK_TOUCH);
335 if (ret)
336 return ret;
337
338 return 0;
339 }
340
s6sy761_hw_init(struct s6sy761_data * sdata,unsigned int * max_x,unsigned int * max_y)341 static int s6sy761_hw_init(struct s6sy761_data *sdata,
342 unsigned int *max_x, unsigned int *max_y)
343 {
344 u8 buffer[S6SY761_PANEL_ID_SIZE]; /* larger read size */
345 int ret;
346
347 ret = s6sy761_power_on(sdata);
348 if (ret)
349 return ret;
350
351 ret = i2c_smbus_read_i2c_block_data(sdata->client,
352 S6SY761_DEVICE_ID,
353 S6SY761_DEVID_SIZE,
354 buffer);
355 if (ret < 0)
356 return ret;
357
358 sdata->devid = get_unaligned_be16(buffer + 1);
359
360 ret = i2c_smbus_read_i2c_block_data(sdata->client,
361 S6SY761_PANEL_INFO,
362 S6SY761_PANEL_ID_SIZE,
363 buffer);
364 if (ret < 0)
365 return ret;
366
367 *max_x = get_unaligned_be16(buffer);
368 *max_y = get_unaligned_be16(buffer + 2);
369
370 /* if no tx channels defined, at least keep one */
371 sdata->tx_channel = max_t(u8, buffer[8], 1);
372
373 ret = i2c_smbus_read_byte_data(sdata->client,
374 S6SY761_FIRMWARE_INTEGRITY);
375 if (ret < 0)
376 return ret;
377 else if (ret != S6SY761_FW_OK)
378 return -ENODEV;
379
380 return 0;
381 }
382
s6sy761_power_off(void * data)383 static void s6sy761_power_off(void *data)
384 {
385 struct s6sy761_data *sdata = data;
386
387 disable_irq(sdata->client->irq);
388 regulator_bulk_disable(ARRAY_SIZE(sdata->regulators),
389 sdata->regulators);
390 }
391
s6sy761_probe(struct i2c_client * client)392 static int s6sy761_probe(struct i2c_client *client)
393 {
394 struct s6sy761_data *sdata;
395 unsigned int max_x, max_y;
396 int err;
397
398 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C |
399 I2C_FUNC_SMBUS_BYTE_DATA |
400 I2C_FUNC_SMBUS_I2C_BLOCK))
401 return -ENODEV;
402
403 sdata = devm_kzalloc(&client->dev, sizeof(*sdata), GFP_KERNEL);
404 if (!sdata)
405 return -ENOMEM;
406
407 i2c_set_clientdata(client, sdata);
408 sdata->client = client;
409
410 sdata->regulators[S6SY761_REGULATOR_VDD].supply = "vdd";
411 sdata->regulators[S6SY761_REGULATOR_AVDD].supply = "avdd";
412 err = devm_regulator_bulk_get(&client->dev,
413 ARRAY_SIZE(sdata->regulators),
414 sdata->regulators);
415 if (err)
416 return err;
417
418 err = devm_add_action_or_reset(&client->dev, s6sy761_power_off, sdata);
419 if (err)
420 return err;
421
422 err = s6sy761_hw_init(sdata, &max_x, &max_y);
423 if (err)
424 return err;
425
426 sdata->input = devm_input_allocate_device(&client->dev);
427 if (!sdata->input)
428 return -ENOMEM;
429
430 sdata->input->name = S6SY761_DEV_NAME;
431 sdata->input->id.bustype = BUS_I2C;
432 sdata->input->open = s6sy761_input_open;
433 sdata->input->close = s6sy761_input_close;
434
435 input_set_abs_params(sdata->input, ABS_MT_POSITION_X, 0, max_x, 0, 0);
436 input_set_abs_params(sdata->input, ABS_MT_POSITION_Y, 0, max_y, 0, 0);
437 input_set_abs_params(sdata->input, ABS_MT_TOUCH_MAJOR, 0, 255, 0, 0);
438 input_set_abs_params(sdata->input, ABS_MT_TOUCH_MINOR, 0, 255, 0, 0);
439 input_set_abs_params(sdata->input, ABS_MT_TOUCH_MAJOR, 0, 255, 0, 0);
440 input_set_abs_params(sdata->input, ABS_MT_TOUCH_MINOR, 0, 255, 0, 0);
441 input_set_abs_params(sdata->input, ABS_MT_PRESSURE, 0, 255, 0, 0);
442
443 touchscreen_parse_properties(sdata->input, true, &sdata->prop);
444
445 if (!input_abs_get_max(sdata->input, ABS_X) ||
446 !input_abs_get_max(sdata->input, ABS_Y)) {
447 dev_warn(&client->dev, "the axis have not been set\n");
448 }
449
450 err = input_mt_init_slots(sdata->input, sdata->tx_channel,
451 INPUT_MT_DIRECT);
452 if (err)
453 return err;
454
455 input_set_drvdata(sdata->input, sdata);
456
457 err = input_register_device(sdata->input);
458 if (err)
459 return err;
460
461 err = devm_request_threaded_irq(&client->dev, client->irq, NULL,
462 s6sy761_irq_handler,
463 IRQF_TRIGGER_LOW | IRQF_ONESHOT,
464 "s6sy761_irq", sdata);
465 if (err)
466 return err;
467
468 err = devm_device_add_group(&client->dev, &s6sy761_attribute_group);
469 if (err)
470 return err;
471
472 pm_runtime_enable(&client->dev);
473
474 return 0;
475 }
476
s6sy761_remove(struct i2c_client * client)477 static void s6sy761_remove(struct i2c_client *client)
478 {
479 pm_runtime_disable(&client->dev);
480 }
481
s6sy761_runtime_suspend(struct device * dev)482 static int s6sy761_runtime_suspend(struct device *dev)
483 {
484 struct s6sy761_data *sdata = dev_get_drvdata(dev);
485
486 return i2c_smbus_write_byte_data(sdata->client,
487 S6SY761_APPLICATION_MODE, S6SY761_APP_SLEEP);
488 }
489
s6sy761_runtime_resume(struct device * dev)490 static int s6sy761_runtime_resume(struct device *dev)
491 {
492 struct s6sy761_data *sdata = dev_get_drvdata(dev);
493
494 return i2c_smbus_write_byte_data(sdata->client,
495 S6SY761_APPLICATION_MODE, S6SY761_APP_NORMAL);
496 }
497
s6sy761_suspend(struct device * dev)498 static int s6sy761_suspend(struct device *dev)
499 {
500 struct s6sy761_data *sdata = dev_get_drvdata(dev);
501
502 s6sy761_power_off(sdata);
503
504 return 0;
505 }
506
s6sy761_resume(struct device * dev)507 static int s6sy761_resume(struct device *dev)
508 {
509 struct s6sy761_data *sdata = dev_get_drvdata(dev);
510
511 enable_irq(sdata->client->irq);
512
513 return s6sy761_power_on(sdata);
514 }
515
516 static const struct dev_pm_ops s6sy761_pm_ops = {
517 SYSTEM_SLEEP_PM_OPS(s6sy761_suspend, s6sy761_resume)
518 RUNTIME_PM_OPS(s6sy761_runtime_suspend, s6sy761_runtime_resume, NULL)
519 };
520
521 #ifdef CONFIG_OF
522 static const struct of_device_id s6sy761_of_match[] = {
523 { .compatible = "samsung,s6sy761", },
524 { },
525 };
526 MODULE_DEVICE_TABLE(of, s6sy761_of_match);
527 #endif
528
529 static const struct i2c_device_id s6sy761_id[] = {
530 { "s6sy761", 0 },
531 { },
532 };
533 MODULE_DEVICE_TABLE(i2c, s6sy761_id);
534
535 static struct i2c_driver s6sy761_driver = {
536 .driver = {
537 .name = S6SY761_DEV_NAME,
538 .of_match_table = of_match_ptr(s6sy761_of_match),
539 .pm = pm_ptr(&s6sy761_pm_ops),
540 },
541 .probe = s6sy761_probe,
542 .remove = s6sy761_remove,
543 .id_table = s6sy761_id,
544 };
545
546 module_i2c_driver(s6sy761_driver);
547
548 MODULE_AUTHOR("Andi Shyti <andi.shyti@samsung.com>");
549 MODULE_DESCRIPTION("Samsung S6SY761 Touch Screen");
550 MODULE_LICENSE("GPL v2");
551