1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Driver for I2C connected EETI EXC3000 multiple touch controller
4 *
5 * Copyright (C) 2017 Ahmet Inan <inan@distec.de>
6 *
7 * minimal implementation based on egalax_ts.c and egalax_i2c.c
8 */
9
10 #include <linux/acpi.h>
11 #include <linux/bitops.h>
12 #include <linux/delay.h>
13 #include <linux/device.h>
14 #include <linux/gpio/consumer.h>
15 #include <linux/i2c.h>
16 #include <linux/input.h>
17 #include <linux/input/mt.h>
18 #include <linux/input/touchscreen.h>
19 #include <linux/interrupt.h>
20 #include <linux/module.h>
21 #include <linux/of.h>
22 #include <linux/regulator/consumer.h>
23 #include <linux/sizes.h>
24 #include <linux/timer.h>
25 #include <linux/unaligned.h>
26
27 #define EXC3000_NUM_SLOTS 10
28 #define EXC3000_SLOTS_PER_FRAME 5
29 #define EXC3000_LEN_FRAME 66
30 #define EXC3000_LEN_VENDOR_REQUEST 68
31 #define EXC3000_LEN_POINT 10
32
33 #define EXC3000_LEN_MODEL_NAME 16
34 #define EXC3000_LEN_FW_VERSION 16
35
36 #define EXC3000_VENDOR_EVENT 0x03
37 #define EXC3000_MT1_EVENT 0x06
38 #define EXC3000_MT2_EVENT 0x18
39
40 #define EXC3000_TIMEOUT_MS 100
41
42 #define EXC3000_RESET_MS 10
43 #define EXC3000_READY_MS 100
44
45 static const struct i2c_device_id exc3000_id[];
46
47 struct eeti_dev_info {
48 const char *name;
49 int max_xy;
50 };
51
52 enum eeti_dev_id {
53 EETI_EXC3000,
54 EETI_EXC80H60,
55 EETI_EXC80H84,
56 EETI_EXC81W32,
57 };
58
59 static struct eeti_dev_info exc3000_info[] = {
60 [EETI_EXC3000] = {
61 .name = "EETI EXC3000 Touch Screen",
62 .max_xy = SZ_4K - 1,
63 },
64 [EETI_EXC80H60] = {
65 .name = "EETI EXC80H60 Touch Screen",
66 .max_xy = SZ_16K - 1,
67 },
68 [EETI_EXC80H84] = {
69 .name = "EETI EXC80H84 Touch Screen",
70 .max_xy = SZ_16K - 1,
71 },
72 [EETI_EXC81W32] = {
73 .name = "EETI EXC81W32 Touch Screen",
74 .max_xy = SZ_16K - 1,
75 },
76 };
77
78 struct exc3000_data {
79 struct i2c_client *client;
80 const struct eeti_dev_info *info;
81 struct input_dev *input;
82 struct touchscreen_properties prop;
83 struct gpio_desc *reset;
84 struct timer_list timer;
85 u8 buf[2 * EXC3000_LEN_FRAME];
86 struct completion wait_event;
87 struct mutex query_lock;
88 };
89
exc3000_report_slots(struct input_dev * input,struct touchscreen_properties * prop,const u8 * buf,int num)90 static void exc3000_report_slots(struct input_dev *input,
91 struct touchscreen_properties *prop,
92 const u8 *buf, int num)
93 {
94 for (; num--; buf += EXC3000_LEN_POINT) {
95 if (buf[0] & BIT(0)) {
96 input_mt_slot(input, buf[1]);
97 input_mt_report_slot_state(input, MT_TOOL_FINGER, true);
98 touchscreen_report_pos(input, prop,
99 get_unaligned_le16(buf + 2),
100 get_unaligned_le16(buf + 4),
101 true);
102 }
103 }
104 }
105
exc3000_timer(struct timer_list * t)106 static void exc3000_timer(struct timer_list *t)
107 {
108 struct exc3000_data *data = from_timer(data, t, timer);
109
110 input_mt_sync_frame(data->input);
111 input_sync(data->input);
112 }
113
exc3000_schedule_timer(struct exc3000_data * data)114 static inline void exc3000_schedule_timer(struct exc3000_data *data)
115 {
116 mod_timer(&data->timer, jiffies + msecs_to_jiffies(EXC3000_TIMEOUT_MS));
117 }
118
exc3000_shutdown_timer(void * timer)119 static void exc3000_shutdown_timer(void *timer)
120 {
121 timer_shutdown_sync(timer);
122 }
123
exc3000_read_frame(struct exc3000_data * data,u8 * buf)124 static int exc3000_read_frame(struct exc3000_data *data, u8 *buf)
125 {
126 struct i2c_client *client = data->client;
127 int ret;
128
129 ret = i2c_master_send(client, "'", 2);
130 if (ret < 0)
131 return ret;
132
133 if (ret != 2)
134 return -EIO;
135
136 ret = i2c_master_recv(client, buf, EXC3000_LEN_FRAME);
137 if (ret < 0)
138 return ret;
139
140 if (ret != EXC3000_LEN_FRAME)
141 return -EIO;
142
143 if (get_unaligned_le16(buf) != EXC3000_LEN_FRAME)
144 return -EINVAL;
145
146 return 0;
147 }
148
exc3000_handle_mt_event(struct exc3000_data * data)149 static int exc3000_handle_mt_event(struct exc3000_data *data)
150 {
151 struct input_dev *input = data->input;
152 int ret, total_slots;
153 u8 *buf = data->buf;
154
155 total_slots = buf[3];
156 if (!total_slots || total_slots > EXC3000_NUM_SLOTS) {
157 ret = -EINVAL;
158 goto out_fail;
159 }
160
161 if (total_slots > EXC3000_SLOTS_PER_FRAME) {
162 /* Read 2nd frame to get the rest of the contacts. */
163 ret = exc3000_read_frame(data, buf + EXC3000_LEN_FRAME);
164 if (ret)
165 goto out_fail;
166
167 /* 2nd chunk must have number of contacts set to 0. */
168 if (buf[EXC3000_LEN_FRAME + 3] != 0) {
169 ret = -EINVAL;
170 goto out_fail;
171 }
172 }
173
174 /*
175 * We read full state successfully, no contacts will be "stuck".
176 */
177 del_timer_sync(&data->timer);
178
179 while (total_slots > 0) {
180 int slots = min(total_slots, EXC3000_SLOTS_PER_FRAME);
181
182 exc3000_report_slots(input, &data->prop, buf + 4, slots);
183 total_slots -= slots;
184 buf += EXC3000_LEN_FRAME;
185 }
186
187 input_mt_sync_frame(input);
188 input_sync(input);
189
190 return 0;
191
192 out_fail:
193 /* Schedule a timer to release "stuck" contacts */
194 exc3000_schedule_timer(data);
195
196 return ret;
197 }
198
exc3000_interrupt(int irq,void * dev_id)199 static irqreturn_t exc3000_interrupt(int irq, void *dev_id)
200 {
201 struct exc3000_data *data = dev_id;
202 u8 *buf = data->buf;
203 int ret;
204
205 ret = exc3000_read_frame(data, buf);
206 if (ret) {
207 /* Schedule a timer to release "stuck" contacts */
208 exc3000_schedule_timer(data);
209 goto out;
210 }
211
212 switch (buf[2]) {
213 case EXC3000_VENDOR_EVENT:
214 complete(&data->wait_event);
215 break;
216
217 case EXC3000_MT1_EVENT:
218 case EXC3000_MT2_EVENT:
219 exc3000_handle_mt_event(data);
220 break;
221
222 default:
223 break;
224 }
225
226 out:
227 return IRQ_HANDLED;
228 }
229
exc3000_vendor_data_request(struct exc3000_data * data,u8 * request,u8 request_len,u8 * response,int timeout)230 static int exc3000_vendor_data_request(struct exc3000_data *data, u8 *request,
231 u8 request_len, u8 *response, int timeout)
232 {
233 u8 buf[EXC3000_LEN_VENDOR_REQUEST] = { 0x67, 0x00, 0x42, 0x00, 0x03 };
234 int ret;
235 unsigned long time_left;
236
237 mutex_lock(&data->query_lock);
238
239 reinit_completion(&data->wait_event);
240
241 buf[5] = request_len;
242 memcpy(&buf[6], request, request_len);
243
244 ret = i2c_master_send(data->client, buf, EXC3000_LEN_VENDOR_REQUEST);
245 if (ret < 0)
246 goto out_unlock;
247
248 if (response) {
249 time_left = wait_for_completion_timeout(&data->wait_event,
250 timeout * HZ);
251 if (time_left == 0) {
252 ret = -ETIMEDOUT;
253 goto out_unlock;
254 }
255
256 if (data->buf[3] >= EXC3000_LEN_FRAME) {
257 ret = -ENOSPC;
258 goto out_unlock;
259 }
260
261 memcpy(response, &data->buf[4], data->buf[3]);
262 ret = data->buf[3];
263 }
264
265 out_unlock:
266 mutex_unlock(&data->query_lock);
267
268 return ret;
269 }
270
fw_version_show(struct device * dev,struct device_attribute * attr,char * buf)271 static ssize_t fw_version_show(struct device *dev,
272 struct device_attribute *attr, char *buf)
273 {
274 struct i2c_client *client = to_i2c_client(dev);
275 struct exc3000_data *data = i2c_get_clientdata(client);
276 u8 response[EXC3000_LEN_FRAME];
277 int ret;
278
279 /* query bootloader info */
280 ret = exc3000_vendor_data_request(data,
281 (u8[]){0x39, 0x02}, 2, response, 1);
282 if (ret < 0)
283 return ret;
284
285 /*
286 * If the bootloader version is non-zero then the device is in
287 * bootloader mode and won't answer a query for the application FW
288 * version, so we just use the bootloader version info.
289 */
290 if (response[2] || response[3])
291 return sprintf(buf, "%d.%d\n", response[2], response[3]);
292
293 ret = exc3000_vendor_data_request(data, (u8[]){'D'}, 1, response, 1);
294 if (ret < 0)
295 return ret;
296
297 return sprintf(buf, "%s\n", &response[1]);
298 }
299 static DEVICE_ATTR_RO(fw_version);
300
model_show(struct device * dev,struct device_attribute * attr,char * buf)301 static ssize_t model_show(struct device *dev,
302 struct device_attribute *attr, char *buf)
303 {
304 struct i2c_client *client = to_i2c_client(dev);
305 struct exc3000_data *data = i2c_get_clientdata(client);
306 u8 response[EXC3000_LEN_FRAME];
307 int ret;
308
309 ret = exc3000_vendor_data_request(data, (u8[]){'E'}, 1, response, 1);
310 if (ret < 0)
311 return ret;
312
313 return sprintf(buf, "%s\n", &response[1]);
314 }
315 static DEVICE_ATTR_RO(model);
316
type_show(struct device * dev,struct device_attribute * attr,char * buf)317 static ssize_t type_show(struct device *dev,
318 struct device_attribute *attr, char *buf)
319 {
320 struct i2c_client *client = to_i2c_client(dev);
321 struct exc3000_data *data = i2c_get_clientdata(client);
322 u8 response[EXC3000_LEN_FRAME];
323 int ret;
324
325 ret = exc3000_vendor_data_request(data, (u8[]){'F'}, 1, response, 1);
326 if (ret < 0)
327 return ret;
328
329 return sprintf(buf, "%s\n", &response[1]);
330 }
331 static DEVICE_ATTR_RO(type);
332
333 static struct attribute *exc3000_attrs[] = {
334 &dev_attr_fw_version.attr,
335 &dev_attr_model.attr,
336 &dev_attr_type.attr,
337 NULL
338 };
339 ATTRIBUTE_GROUPS(exc3000);
340
exc3000_probe(struct i2c_client * client)341 static int exc3000_probe(struct i2c_client *client)
342 {
343 struct exc3000_data *data;
344 struct input_dev *input;
345 int error, max_xy, retry;
346
347 data = devm_kzalloc(&client->dev, sizeof(*data), GFP_KERNEL);
348 if (!data)
349 return -ENOMEM;
350
351 data->client = client;
352 data->info = device_get_match_data(&client->dev);
353 if (!data->info) {
354 enum eeti_dev_id eeti_dev_id =
355 i2c_match_id(exc3000_id, client)->driver_data;
356 data->info = &exc3000_info[eeti_dev_id];
357 }
358 timer_setup(&data->timer, exc3000_timer, 0);
359 init_completion(&data->wait_event);
360 mutex_init(&data->query_lock);
361
362 data->reset = devm_gpiod_get_optional(&client->dev, "reset",
363 GPIOD_OUT_HIGH);
364 if (IS_ERR(data->reset))
365 return PTR_ERR(data->reset);
366
367 /* For proper reset sequence, enable power while reset asserted */
368 error = devm_regulator_get_enable(&client->dev, "vdd");
369 if (error && error != -ENODEV)
370 return dev_err_probe(&client->dev, error,
371 "failed to request vdd regulator\n");
372
373 if (data->reset) {
374 msleep(EXC3000_RESET_MS);
375 gpiod_set_value_cansleep(data->reset, 0);
376 msleep(EXC3000_READY_MS);
377 }
378
379 input = devm_input_allocate_device(&client->dev);
380 if (!input)
381 return -ENOMEM;
382
383 data->input = input;
384 input_set_drvdata(input, data);
385
386 input->name = data->info->name;
387 input->id.bustype = BUS_I2C;
388
389 max_xy = data->info->max_xy;
390 input_set_abs_params(input, ABS_MT_POSITION_X, 0, max_xy, 0, 0);
391 input_set_abs_params(input, ABS_MT_POSITION_Y, 0, max_xy, 0, 0);
392
393 touchscreen_parse_properties(input, true, &data->prop);
394
395 error = input_mt_init_slots(input, EXC3000_NUM_SLOTS,
396 INPUT_MT_DIRECT | INPUT_MT_DROP_UNUSED);
397 if (error)
398 return error;
399
400 error = input_register_device(input);
401 if (error)
402 return error;
403
404 error = devm_add_action_or_reset(&client->dev, exc3000_shutdown_timer,
405 &data->timer);
406 if (error)
407 return error;
408
409 error = devm_request_threaded_irq(&client->dev, client->irq,
410 NULL, exc3000_interrupt, IRQF_ONESHOT,
411 client->name, data);
412 if (error)
413 return error;
414
415 /*
416 * I²C does not have built-in recovery, so retry on failure. This
417 * ensures, that the device probe will not fail for temporary issues
418 * on the bus. This is not needed for the sysfs calls (userspace
419 * will receive the error code and can start another query) and
420 * cannot be done for touch events (but that only means loosing one
421 * or two touch events anyways).
422 */
423 for (retry = 0; retry < 3; retry++) {
424 u8 response[EXC3000_LEN_FRAME];
425
426 error = exc3000_vendor_data_request(data, (u8[]){'E'}, 1,
427 response, 1);
428 if (error > 0) {
429 dev_dbg(&client->dev, "TS Model: %s", &response[1]);
430 error = 0;
431 break;
432 }
433 dev_warn(&client->dev, "Retry %d get EETI EXC3000 model: %d\n",
434 retry + 1, error);
435 }
436
437 if (error)
438 return error;
439
440 i2c_set_clientdata(client, data);
441
442 return 0;
443 }
444
445 static const struct i2c_device_id exc3000_id[] = {
446 { "exc3000", EETI_EXC3000 },
447 { "exc80h60", EETI_EXC80H60 },
448 { "exc80h84", EETI_EXC80H84 },
449 { "exc81w32", EETI_EXC81W32 },
450 { }
451 };
452 MODULE_DEVICE_TABLE(i2c, exc3000_id);
453
454 #ifdef CONFIG_OF
455 static const struct of_device_id exc3000_of_match[] = {
456 { .compatible = "eeti,exc3000", .data = &exc3000_info[EETI_EXC3000] },
457 { .compatible = "eeti,exc80h60", .data = &exc3000_info[EETI_EXC80H60] },
458 { .compatible = "eeti,exc80h84", .data = &exc3000_info[EETI_EXC80H84] },
459 { .compatible = "eeti,exc81w32", .data = &exc3000_info[EETI_EXC81W32] },
460 { }
461 };
462 MODULE_DEVICE_TABLE(of, exc3000_of_match);
463 #endif
464
465 #ifdef CONFIG_ACPI
466 static const struct acpi_device_id exc3000_acpi_match[] = {
467 { "EGA00001", .driver_data = (kernel_ulong_t)&exc3000_info[EETI_EXC80H60] },
468 { }
469 };
470 MODULE_DEVICE_TABLE(acpi, exc3000_acpi_match);
471 #endif
472
473 static struct i2c_driver exc3000_driver = {
474 .driver = {
475 .name = "exc3000",
476 .dev_groups = exc3000_groups,
477 .of_match_table = of_match_ptr(exc3000_of_match),
478 .acpi_match_table = ACPI_PTR(exc3000_acpi_match),
479 },
480 .id_table = exc3000_id,
481 .probe = exc3000_probe,
482 };
483
484 module_i2c_driver(exc3000_driver);
485
486 MODULE_AUTHOR("Ahmet Inan <inan@distec.de>");
487 MODULE_DESCRIPTION("I2C connected EETI EXC3000 multiple touch controller driver");
488 MODULE_LICENSE("GPL v2");
489