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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 <[email protected]>
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
45static const struct i2c_device_id exc3000_id[];
46
47struct eeti_dev_info {
48 const char *name;
49 int max_xy;
50};
51
52enum eeti_dev_id {
53 EETI_EXC3000,
54 EETI_EXC80H60,
55 EETI_EXC80H84,
56 EETI_EXC81W32,
57};
58
59static 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
78struct 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
90static 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
106static void exc3000_timer(struct timer_list *t)
107{
108 struct exc3000_data *data = timer_container_of(data, t, timer);
109
110 input_mt_sync_frame(data->input);
111 input_sync(data->input);
112}
113
114static inline void exc3000_schedule_timer(struct exc3000_data *data)
115{
116 mod_timer(&data->timer, jiffies + msecs_to_jiffies(EXC3000_TIMEOUT_MS));
117}
118
119static void exc3000_shutdown_timer(void *timer)
120{
121 timer_shutdown_sync(timer);
122}
123
124static 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
149static 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 timer_delete_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
192out_fail:
193 /* Schedule a timer to release "stuck" contacts */
194 exc3000_schedule_timer(data);
195
196 return ret;
197}
198
199static 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
226out:
227 return IRQ_HANDLED;
228}
229
230static 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 guard(mutex)(&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 return ret;
247
248 time_left = wait_for_completion_timeout(&data->wait_event,
249 timeout * HZ);
250 if (time_left == 0)
251 return -ETIMEDOUT;
252
253 if (data->buf[3] >= EXC3000_LEN_FRAME)
254 return -ENOSPC;
255
256 memcpy(response, &data->buf[4], data->buf[3]);
257 return data->buf[3];
258}
259
260static ssize_t fw_version_show(struct device *dev,
261 struct device_attribute *attr, char *buf)
262{
263 struct i2c_client *client = to_i2c_client(dev);
264 struct exc3000_data *data = i2c_get_clientdata(client);
265 u8 response[EXC3000_LEN_FRAME];
266 int ret;
267
268 /* query bootloader info */
269 ret = exc3000_vendor_data_request(data,
270 (u8[]){0x39, 0x02}, 2, response, 1);
271 if (ret < 0)
272 return ret;
273
274 /*
275 * If the bootloader version is non-zero then the device is in
276 * bootloader mode and won't answer a query for the application FW
277 * version, so we just use the bootloader version info.
278 */
279 if (response[2] || response[3])
280 return sprintf(buf, "%d.%d\n", response[2], response[3]);
281
282 ret = exc3000_vendor_data_request(data, (u8[]){'D'}, 1, response, 1);
283 if (ret < 0)
284 return ret;
285
286 return sprintf(buf, "%s\n", &response[1]);
287}
288static DEVICE_ATTR_RO(fw_version);
289
290static ssize_t model_show(struct device *dev,
291 struct device_attribute *attr, char *buf)
292{
293 struct i2c_client *client = to_i2c_client(dev);
294 struct exc3000_data *data = i2c_get_clientdata(client);
295 u8 response[EXC3000_LEN_FRAME];
296 int ret;
297
298 ret = exc3000_vendor_data_request(data, (u8[]){'E'}, 1, response, 1);
299 if (ret < 0)
300 return ret;
301
302 return sprintf(buf, "%s\n", &response[1]);
303}
304static DEVICE_ATTR_RO(model);
305
306static ssize_t type_show(struct device *dev,
307 struct device_attribute *attr, char *buf)
308{
309 struct i2c_client *client = to_i2c_client(dev);
310 struct exc3000_data *data = i2c_get_clientdata(client);
311 u8 response[EXC3000_LEN_FRAME];
312 int ret;
313
314 ret = exc3000_vendor_data_request(data, (u8[]){'F'}, 1, response, 1);
315 if (ret < 0)
316 return ret;
317
318 return sprintf(buf, "%s\n", &response[1]);
319}
320static DEVICE_ATTR_RO(type);
321
322static struct attribute *exc3000_attrs[] = {
323 &dev_attr_fw_version.attr,
324 &dev_attr_model.attr,
325 &dev_attr_type.attr,
326 NULL
327};
328ATTRIBUTE_GROUPS(exc3000);
329
330static int exc3000_probe(struct i2c_client *client)
331{
332 struct exc3000_data *data;
333 struct input_dev *input;
334 int error, max_xy, retry;
335
336 data = devm_kzalloc(&client->dev, sizeof(*data), GFP_KERNEL);
337 if (!data)
338 return -ENOMEM;
339
340 data->client = client;
341 data->info = device_get_match_data(&client->dev);
342 if (!data->info) {
343 enum eeti_dev_id eeti_dev_id =
344 i2c_match_id(exc3000_id, client)->driver_data;
345 data->info = &exc3000_info[eeti_dev_id];
346 }
347 timer_setup(&data->timer, exc3000_timer, 0);
348 init_completion(&data->wait_event);
349 mutex_init(&data->query_lock);
350
351 data->reset = devm_gpiod_get_optional(&client->dev, "reset",
352 GPIOD_OUT_HIGH);
353 if (IS_ERR(data->reset))
354 return PTR_ERR(data->reset);
355
356 /* For proper reset sequence, enable power while reset asserted */
357 error = devm_regulator_get_enable(&client->dev, "vdd");
358 if (error && error != -ENODEV)
359 return dev_err_probe(&client->dev, error,
360 "failed to request vdd regulator\n");
361
362 if (data->reset) {
363 msleep(EXC3000_RESET_MS);
364 gpiod_set_value_cansleep(data->reset, 0);
365 msleep(EXC3000_READY_MS);
366 }
367
368 input = devm_input_allocate_device(&client->dev);
369 if (!input)
370 return -ENOMEM;
371
372 data->input = input;
373 input_set_drvdata(input, data);
374
375 input->name = data->info->name;
376 input->id.bustype = BUS_I2C;
377
378 max_xy = data->info->max_xy;
379 input_set_abs_params(input, ABS_MT_POSITION_X, 0, max_xy, 0, 0);
380 input_set_abs_params(input, ABS_MT_POSITION_Y, 0, max_xy, 0, 0);
381
382 touchscreen_parse_properties(input, true, &data->prop);
383
384 error = input_mt_init_slots(input, EXC3000_NUM_SLOTS,
385 INPUT_MT_DIRECT | INPUT_MT_DROP_UNUSED);
386 if (error)
387 return error;
388
389 error = input_register_device(input);
390 if (error)
391 return error;
392
393 error = devm_add_action_or_reset(&client->dev, exc3000_shutdown_timer,
394 &data->timer);
395 if (error)
396 return error;
397
398 error = devm_request_threaded_irq(&client->dev, client->irq,
399 NULL, exc3000_interrupt, IRQF_ONESHOT,
400 client->name, data);
401 if (error)
402 return error;
403
404 /*
405 * I²C does not have built-in recovery, so retry on failure. This
406 * ensures, that the device probe will not fail for temporary issues
407 * on the bus. This is not needed for the sysfs calls (userspace
408 * will receive the error code and can start another query) and
409 * cannot be done for touch events (but that only means loosing one
410 * or two touch events anyways).
411 */
412 for (retry = 0; retry < 3; retry++) {
413 u8 response[EXC3000_LEN_FRAME];
414
415 error = exc3000_vendor_data_request(data, (u8[]){'E'}, 1,
416 response, 1);
417 if (error > 0) {
418 dev_dbg(&client->dev, "TS Model: %s", &response[1]);
419 error = 0;
420 break;
421 }
422 dev_warn(&client->dev, "Retry %d get EETI EXC3000 model: %d\n",
423 retry + 1, error);
424 }
425
426 if (error)
427 return error;
428
429 i2c_set_clientdata(client, data);
430
431 return 0;
432}
433
434static const struct i2c_device_id exc3000_id[] = {
435 { .name = "exc3000", .driver_data = EETI_EXC3000 },
436 { .name = "exc80h60", .driver_data = EETI_EXC80H60 },
437 { .name = "exc80h84", .driver_data = EETI_EXC80H84 },
438 { .name = "exc81w32", .driver_data = EETI_EXC81W32 },
439 { }
440};
441MODULE_DEVICE_TABLE(i2c, exc3000_id);
442
443#ifdef CONFIG_OF
444static const struct of_device_id exc3000_of_match[] = {
445 { .compatible = "eeti,exc3000", .data = &exc3000_info[EETI_EXC3000] },
446 { .compatible = "eeti,exc80h60", .data = &exc3000_info[EETI_EXC80H60] },
447 { .compatible = "eeti,exc80h84", .data = &exc3000_info[EETI_EXC80H84] },
448 { .compatible = "eeti,exc81w32", .data = &exc3000_info[EETI_EXC81W32] },
449 { }
450};
451MODULE_DEVICE_TABLE(of, exc3000_of_match);
452#endif
453
454#ifdef CONFIG_ACPI
455static const struct acpi_device_id exc3000_acpi_match[] = {
456 { "EGA00001", .driver_data = (kernel_ulong_t)&exc3000_info[EETI_EXC80H60] },
457 { }
458};
459MODULE_DEVICE_TABLE(acpi, exc3000_acpi_match);
460#endif
461
462static struct i2c_driver exc3000_driver = {
463 .driver = {
464 .name = "exc3000",
465 .dev_groups = exc3000_groups,
466 .of_match_table = of_match_ptr(exc3000_of_match),
467 .acpi_match_table = ACPI_PTR(exc3000_acpi_match),
468 },
469 .id_table = exc3000_id,
470 .probe = exc3000_probe,
471};
472
473module_i2c_driver(exc3000_driver);
474
475MODULE_AUTHOR("Ahmet Inan <[email protected]>");
476MODULE_DESCRIPTION("I2C connected EETI EXC3000 multiple touch controller driver");
477MODULE_LICENSE("GPL v2");