1 // SPDX-License-Identifier: GPL-2.0-only
3 * Driver for I2C connected EETI EXC3000 multiple touch controller
5 * Copyright (C) 2017 Ahmet Inan <inan@distec.de>
7 * minimal implementation based on egalax_ts.c and egalax_i2c.c
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>
22 #include <linux/regulator/consumer.h>
23 #include <linux/sizes.h>
24 #include <linux/timer.h>
25 #include <asm/unaligned.h>
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
33 #define EXC3000_LEN_MODEL_NAME 16
34 #define EXC3000_LEN_FW_VERSION 16
36 #define EXC3000_VENDOR_EVENT 0x03
37 #define EXC3000_MT1_EVENT 0x06
38 #define EXC3000_MT2_EVENT 0x18
40 #define EXC3000_TIMEOUT_MS 100
42 #define EXC3000_RESET_MS 10
43 #define EXC3000_READY_MS 100
45 static const struct i2c_device_id exc3000_id[];
47 struct eeti_dev_info {
58 static struct eeti_dev_info exc3000_info[] = {
60 .name = "EETI EXC3000 Touch Screen",
64 .name = "EETI EXC80H60 Touch Screen",
68 .name = "EETI EXC80H84 Touch Screen",
74 struct i2c_client *client;
75 const struct eeti_dev_info *info;
76 struct input_dev *input;
77 struct touchscreen_properties prop;
78 struct gpio_desc *reset;
79 struct timer_list timer;
80 u8 buf[2 * EXC3000_LEN_FRAME];
81 struct completion wait_event;
82 struct mutex query_lock;
85 static void exc3000_report_slots(struct input_dev *input,
86 struct touchscreen_properties *prop,
87 const u8 *buf, int num)
89 for (; num--; buf += EXC3000_LEN_POINT) {
90 if (buf[0] & BIT(0)) {
91 input_mt_slot(input, buf[1]);
92 input_mt_report_slot_state(input, MT_TOOL_FINGER, true);
93 touchscreen_report_pos(input, prop,
94 get_unaligned_le16(buf + 2),
95 get_unaligned_le16(buf + 4),
101 static void exc3000_timer(struct timer_list *t)
103 struct exc3000_data *data = from_timer(data, t, timer);
105 input_mt_sync_frame(data->input);
106 input_sync(data->input);
109 static inline void exc3000_schedule_timer(struct exc3000_data *data)
111 mod_timer(&data->timer, jiffies + msecs_to_jiffies(EXC3000_TIMEOUT_MS));
114 static void exc3000_shutdown_timer(void *timer)
116 timer_shutdown_sync(timer);
119 static int exc3000_read_frame(struct exc3000_data *data, u8 *buf)
121 struct i2c_client *client = data->client;
124 ret = i2c_master_send(client, "'", 2);
131 ret = i2c_master_recv(client, buf, EXC3000_LEN_FRAME);
135 if (ret != EXC3000_LEN_FRAME)
138 if (get_unaligned_le16(buf) != EXC3000_LEN_FRAME)
144 static int exc3000_handle_mt_event(struct exc3000_data *data)
146 struct input_dev *input = data->input;
147 int ret, total_slots;
150 total_slots = buf[3];
151 if (!total_slots || total_slots > EXC3000_NUM_SLOTS) {
156 if (total_slots > EXC3000_SLOTS_PER_FRAME) {
157 /* Read 2nd frame to get the rest of the contacts. */
158 ret = exc3000_read_frame(data, buf + EXC3000_LEN_FRAME);
162 /* 2nd chunk must have number of contacts set to 0. */
163 if (buf[EXC3000_LEN_FRAME + 3] != 0) {
170 * We read full state successfully, no contacts will be "stuck".
172 del_timer_sync(&data->timer);
174 while (total_slots > 0) {
175 int slots = min(total_slots, EXC3000_SLOTS_PER_FRAME);
177 exc3000_report_slots(input, &data->prop, buf + 4, slots);
178 total_slots -= slots;
179 buf += EXC3000_LEN_FRAME;
182 input_mt_sync_frame(input);
188 /* Schedule a timer to release "stuck" contacts */
189 exc3000_schedule_timer(data);
194 static irqreturn_t exc3000_interrupt(int irq, void *dev_id)
196 struct exc3000_data *data = dev_id;
200 ret = exc3000_read_frame(data, buf);
202 /* Schedule a timer to release "stuck" contacts */
203 exc3000_schedule_timer(data);
208 case EXC3000_VENDOR_EVENT:
209 complete(&data->wait_event);
212 case EXC3000_MT1_EVENT:
213 case EXC3000_MT2_EVENT:
214 exc3000_handle_mt_event(data);
225 static int exc3000_vendor_data_request(struct exc3000_data *data, u8 *request,
226 u8 request_len, u8 *response, int timeout)
228 u8 buf[EXC3000_LEN_VENDOR_REQUEST] = { 0x67, 0x00, 0x42, 0x00, 0x03 };
230 unsigned long time_left;
232 mutex_lock(&data->query_lock);
234 reinit_completion(&data->wait_event);
236 buf[5] = request_len;
237 memcpy(&buf[6], request, request_len);
239 ret = i2c_master_send(data->client, buf, EXC3000_LEN_VENDOR_REQUEST);
244 time_left = wait_for_completion_timeout(&data->wait_event,
246 if (time_left == 0) {
251 if (data->buf[3] >= EXC3000_LEN_FRAME) {
256 memcpy(response, &data->buf[4], data->buf[3]);
261 mutex_unlock(&data->query_lock);
266 static ssize_t fw_version_show(struct device *dev,
267 struct device_attribute *attr, char *buf)
269 struct i2c_client *client = to_i2c_client(dev);
270 struct exc3000_data *data = i2c_get_clientdata(client);
271 u8 response[EXC3000_LEN_FRAME];
274 /* query bootloader info */
275 ret = exc3000_vendor_data_request(data,
276 (u8[]){0x39, 0x02}, 2, response, 1);
281 * If the bootloader version is non-zero then the device is in
282 * bootloader mode and won't answer a query for the application FW
283 * version, so we just use the bootloader version info.
285 if (response[2] || response[3])
286 return sprintf(buf, "%d.%d\n", response[2], response[3]);
288 ret = exc3000_vendor_data_request(data, (u8[]){'D'}, 1, response, 1);
292 return sprintf(buf, "%s\n", &response[1]);
294 static DEVICE_ATTR_RO(fw_version);
296 static ssize_t model_show(struct device *dev,
297 struct device_attribute *attr, char *buf)
299 struct i2c_client *client = to_i2c_client(dev);
300 struct exc3000_data *data = i2c_get_clientdata(client);
301 u8 response[EXC3000_LEN_FRAME];
304 ret = exc3000_vendor_data_request(data, (u8[]){'E'}, 1, response, 1);
308 return sprintf(buf, "%s\n", &response[1]);
310 static DEVICE_ATTR_RO(model);
312 static ssize_t type_show(struct device *dev,
313 struct device_attribute *attr, char *buf)
315 struct i2c_client *client = to_i2c_client(dev);
316 struct exc3000_data *data = i2c_get_clientdata(client);
317 u8 response[EXC3000_LEN_FRAME];
320 ret = exc3000_vendor_data_request(data, (u8[]){'F'}, 1, response, 1);
324 return sprintf(buf, "%s\n", &response[1]);
326 static DEVICE_ATTR_RO(type);
328 static struct attribute *exc3000_attrs[] = {
329 &dev_attr_fw_version.attr,
330 &dev_attr_model.attr,
334 ATTRIBUTE_GROUPS(exc3000);
336 static int exc3000_probe(struct i2c_client *client)
338 struct exc3000_data *data;
339 struct input_dev *input;
340 int error, max_xy, retry;
342 data = devm_kzalloc(&client->dev, sizeof(*data), GFP_KERNEL);
346 data->client = client;
347 data->info = device_get_match_data(&client->dev);
349 enum eeti_dev_id eeti_dev_id =
350 i2c_match_id(exc3000_id, client)->driver_data;
351 data->info = &exc3000_info[eeti_dev_id];
353 timer_setup(&data->timer, exc3000_timer, 0);
354 init_completion(&data->wait_event);
355 mutex_init(&data->query_lock);
357 data->reset = devm_gpiod_get_optional(&client->dev, "reset",
359 if (IS_ERR(data->reset))
360 return PTR_ERR(data->reset);
362 /* For proper reset sequence, enable power while reset asserted */
363 error = devm_regulator_get_enable(&client->dev, "vdd");
364 if (error && error != -ENODEV)
365 return dev_err_probe(&client->dev, error,
366 "failed to request vdd regulator\n");
369 msleep(EXC3000_RESET_MS);
370 gpiod_set_value_cansleep(data->reset, 0);
371 msleep(EXC3000_READY_MS);
374 input = devm_input_allocate_device(&client->dev);
379 input_set_drvdata(input, data);
381 input->name = data->info->name;
382 input->id.bustype = BUS_I2C;
384 max_xy = data->info->max_xy;
385 input_set_abs_params(input, ABS_MT_POSITION_X, 0, max_xy, 0, 0);
386 input_set_abs_params(input, ABS_MT_POSITION_Y, 0, max_xy, 0, 0);
388 touchscreen_parse_properties(input, true, &data->prop);
390 error = input_mt_init_slots(input, EXC3000_NUM_SLOTS,
391 INPUT_MT_DIRECT | INPUT_MT_DROP_UNUSED);
395 error = input_register_device(input);
399 error = devm_add_action_or_reset(&client->dev, exc3000_shutdown_timer,
404 error = devm_request_threaded_irq(&client->dev, client->irq,
405 NULL, exc3000_interrupt, IRQF_ONESHOT,
411 * I²C does not have built-in recovery, so retry on failure. This
412 * ensures, that the device probe will not fail for temporary issues
413 * on the bus. This is not needed for the sysfs calls (userspace
414 * will receive the error code and can start another query) and
415 * cannot be done for touch events (but that only means loosing one
416 * or two touch events anyways).
418 for (retry = 0; retry < 3; retry++) {
419 u8 response[EXC3000_LEN_FRAME];
421 error = exc3000_vendor_data_request(data, (u8[]){'E'}, 1,
424 dev_dbg(&client->dev, "TS Model: %s", &response[1]);
428 dev_warn(&client->dev, "Retry %d get EETI EXC3000 model: %d\n",
435 i2c_set_clientdata(client, data);
440 static const struct i2c_device_id exc3000_id[] = {
441 { "exc3000", EETI_EXC3000 },
442 { "exc80h60", EETI_EXC80H60 },
443 { "exc80h84", EETI_EXC80H84 },
446 MODULE_DEVICE_TABLE(i2c, exc3000_id);
449 static const struct of_device_id exc3000_of_match[] = {
450 { .compatible = "eeti,exc3000", .data = &exc3000_info[EETI_EXC3000] },
451 { .compatible = "eeti,exc80h60", .data = &exc3000_info[EETI_EXC80H60] },
452 { .compatible = "eeti,exc80h84", .data = &exc3000_info[EETI_EXC80H84] },
455 MODULE_DEVICE_TABLE(of, exc3000_of_match);
459 static const struct acpi_device_id exc3000_acpi_match[] = {
460 { "EGA00001", .driver_data = (kernel_ulong_t)&exc3000_info[EETI_EXC80H60] },
463 MODULE_DEVICE_TABLE(acpi, exc3000_acpi_match);
466 static struct i2c_driver exc3000_driver = {
469 .dev_groups = exc3000_groups,
470 .of_match_table = of_match_ptr(exc3000_of_match),
471 .acpi_match_table = ACPI_PTR(exc3000_acpi_match),
473 .id_table = exc3000_id,
474 .probe = exc3000_probe,
477 module_i2c_driver(exc3000_driver);
479 MODULE_AUTHOR("Ahmet Inan <inan@distec.de>");
480 MODULE_DESCRIPTION("I2C connected EETI EXC3000 multiple touch controller driver");
481 MODULE_LICENSE("GPL v2");