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 <asm/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 }; 57 58 static struct eeti_dev_info exc3000_info[] = { 59 [EETI_EXC3000] = { 60 .name = "EETI EXC3000 Touch Screen", 61 .max_xy = SZ_4K - 1, 62 }, 63 [EETI_EXC80H60] = { 64 .name = "EETI EXC80H60 Touch Screen", 65 .max_xy = SZ_16K - 1, 66 }, 67 [EETI_EXC80H84] = { 68 .name = "EETI EXC80H84 Touch Screen", 69 .max_xy = SZ_16K - 1, 70 }, 71 }; 72 73 struct exc3000_data { 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; 83 }; 84 85 static void exc3000_report_slots(struct input_dev *input, 86 struct touchscreen_properties *prop, 87 const u8 *buf, int num) 88 { 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), 96 true); 97 } 98 } 99 } 100 101 static void exc3000_timer(struct timer_list *t) 102 { 103 struct exc3000_data *data = from_timer(data, t, timer); 104 105 input_mt_sync_frame(data->input); 106 input_sync(data->input); 107 } 108 109 static inline void exc3000_schedule_timer(struct exc3000_data *data) 110 { 111 mod_timer(&data->timer, jiffies + msecs_to_jiffies(EXC3000_TIMEOUT_MS)); 112 } 113 114 static void exc3000_shutdown_timer(void *timer) 115 { 116 timer_shutdown_sync(timer); 117 } 118 119 static int exc3000_read_frame(struct exc3000_data *data, u8 *buf) 120 { 121 struct i2c_client *client = data->client; 122 int ret; 123 124 ret = i2c_master_send(client, "'", 2); 125 if (ret < 0) 126 return ret; 127 128 if (ret != 2) 129 return -EIO; 130 131 ret = i2c_master_recv(client, buf, EXC3000_LEN_FRAME); 132 if (ret < 0) 133 return ret; 134 135 if (ret != EXC3000_LEN_FRAME) 136 return -EIO; 137 138 if (get_unaligned_le16(buf) != EXC3000_LEN_FRAME) 139 return -EINVAL; 140 141 return 0; 142 } 143 144 static int exc3000_handle_mt_event(struct exc3000_data *data) 145 { 146 struct input_dev *input = data->input; 147 int ret, total_slots; 148 u8 *buf = data->buf; 149 150 total_slots = buf[3]; 151 if (!total_slots || total_slots > EXC3000_NUM_SLOTS) { 152 ret = -EINVAL; 153 goto out_fail; 154 } 155 156 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); 159 if (ret) 160 goto out_fail; 161 162 /* 2nd chunk must have number of contacts set to 0. */ 163 if (buf[EXC3000_LEN_FRAME + 3] != 0) { 164 ret = -EINVAL; 165 goto out_fail; 166 } 167 } 168 169 /* 170 * We read full state successfully, no contacts will be "stuck". 171 */ 172 del_timer_sync(&data->timer); 173 174 while (total_slots > 0) { 175 int slots = min(total_slots, EXC3000_SLOTS_PER_FRAME); 176 177 exc3000_report_slots(input, &data->prop, buf + 4, slots); 178 total_slots -= slots; 179 buf += EXC3000_LEN_FRAME; 180 } 181 182 input_mt_sync_frame(input); 183 input_sync(input); 184 185 return 0; 186 187 out_fail: 188 /* Schedule a timer to release "stuck" contacts */ 189 exc3000_schedule_timer(data); 190 191 return ret; 192 } 193 194 static irqreturn_t exc3000_interrupt(int irq, void *dev_id) 195 { 196 struct exc3000_data *data = dev_id; 197 u8 *buf = data->buf; 198 int ret; 199 200 ret = exc3000_read_frame(data, buf); 201 if (ret) { 202 /* Schedule a timer to release "stuck" contacts */ 203 exc3000_schedule_timer(data); 204 goto out; 205 } 206 207 switch (buf[2]) { 208 case EXC3000_VENDOR_EVENT: 209 complete(&data->wait_event); 210 break; 211 212 case EXC3000_MT1_EVENT: 213 case EXC3000_MT2_EVENT: 214 exc3000_handle_mt_event(data); 215 break; 216 217 default: 218 break; 219 } 220 221 out: 222 return IRQ_HANDLED; 223 } 224 225 static int exc3000_vendor_data_request(struct exc3000_data *data, u8 *request, 226 u8 request_len, u8 *response, int timeout) 227 { 228 u8 buf[EXC3000_LEN_VENDOR_REQUEST] = { 0x67, 0x00, 0x42, 0x00, 0x03 }; 229 int ret; 230 unsigned long time_left; 231 232 mutex_lock(&data->query_lock); 233 234 reinit_completion(&data->wait_event); 235 236 buf[5] = request_len; 237 memcpy(&buf[6], request, request_len); 238 239 ret = i2c_master_send(data->client, buf, EXC3000_LEN_VENDOR_REQUEST); 240 if (ret < 0) 241 goto out_unlock; 242 243 if (response) { 244 time_left = wait_for_completion_timeout(&data->wait_event, 245 timeout * HZ); 246 if (time_left == 0) { 247 ret = -ETIMEDOUT; 248 goto out_unlock; 249 } 250 251 if (data->buf[3] >= EXC3000_LEN_FRAME) { 252 ret = -ENOSPC; 253 goto out_unlock; 254 } 255 256 memcpy(response, &data->buf[4], data->buf[3]); 257 ret = data->buf[3]; 258 } 259 260 out_unlock: 261 mutex_unlock(&data->query_lock); 262 263 return ret; 264 } 265 266 static ssize_t fw_version_show(struct device *dev, 267 struct device_attribute *attr, char *buf) 268 { 269 struct i2c_client *client = to_i2c_client(dev); 270 struct exc3000_data *data = i2c_get_clientdata(client); 271 u8 response[EXC3000_LEN_FRAME]; 272 int ret; 273 274 /* query bootloader info */ 275 ret = exc3000_vendor_data_request(data, 276 (u8[]){0x39, 0x02}, 2, response, 1); 277 if (ret < 0) 278 return ret; 279 280 /* 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. 284 */ 285 if (response[2] || response[3]) 286 return sprintf(buf, "%d.%d\n", response[2], response[3]); 287 288 ret = exc3000_vendor_data_request(data, (u8[]){'D'}, 1, response, 1); 289 if (ret < 0) 290 return ret; 291 292 return sprintf(buf, "%s\n", &response[1]); 293 } 294 static DEVICE_ATTR_RO(fw_version); 295 296 static ssize_t model_show(struct device *dev, 297 struct device_attribute *attr, char *buf) 298 { 299 struct i2c_client *client = to_i2c_client(dev); 300 struct exc3000_data *data = i2c_get_clientdata(client); 301 u8 response[EXC3000_LEN_FRAME]; 302 int ret; 303 304 ret = exc3000_vendor_data_request(data, (u8[]){'E'}, 1, response, 1); 305 if (ret < 0) 306 return ret; 307 308 return sprintf(buf, "%s\n", &response[1]); 309 } 310 static DEVICE_ATTR_RO(model); 311 312 static ssize_t type_show(struct device *dev, 313 struct device_attribute *attr, char *buf) 314 { 315 struct i2c_client *client = to_i2c_client(dev); 316 struct exc3000_data *data = i2c_get_clientdata(client); 317 u8 response[EXC3000_LEN_FRAME]; 318 int ret; 319 320 ret = exc3000_vendor_data_request(data, (u8[]){'F'}, 1, response, 1); 321 if (ret < 0) 322 return ret; 323 324 return sprintf(buf, "%s\n", &response[1]); 325 } 326 static DEVICE_ATTR_RO(type); 327 328 static struct attribute *sysfs_attrs[] = { 329 &dev_attr_fw_version.attr, 330 &dev_attr_model.attr, 331 &dev_attr_type.attr, 332 NULL 333 }; 334 335 static struct attribute_group exc3000_attribute_group = { 336 .attrs = sysfs_attrs 337 }; 338 339 static int exc3000_probe(struct i2c_client *client) 340 { 341 struct exc3000_data *data; 342 struct input_dev *input; 343 int error, max_xy, retry; 344 345 data = devm_kzalloc(&client->dev, sizeof(*data), GFP_KERNEL); 346 if (!data) 347 return -ENOMEM; 348 349 data->client = client; 350 data->info = device_get_match_data(&client->dev); 351 if (!data->info) { 352 enum eeti_dev_id eeti_dev_id = 353 i2c_match_id(exc3000_id, client)->driver_data; 354 data->info = &exc3000_info[eeti_dev_id]; 355 } 356 timer_setup(&data->timer, exc3000_timer, 0); 357 init_completion(&data->wait_event); 358 mutex_init(&data->query_lock); 359 360 data->reset = devm_gpiod_get_optional(&client->dev, "reset", 361 GPIOD_OUT_HIGH); 362 if (IS_ERR(data->reset)) 363 return PTR_ERR(data->reset); 364 365 /* For proper reset sequence, enable power while reset asserted */ 366 error = devm_regulator_get_enable(&client->dev, "vdd"); 367 if (error && error != -ENODEV) 368 return dev_err_probe(&client->dev, error, 369 "failed to request vdd regulator\n"); 370 371 if (data->reset) { 372 msleep(EXC3000_RESET_MS); 373 gpiod_set_value_cansleep(data->reset, 0); 374 msleep(EXC3000_READY_MS); 375 } 376 377 input = devm_input_allocate_device(&client->dev); 378 if (!input) 379 return -ENOMEM; 380 381 data->input = input; 382 input_set_drvdata(input, data); 383 384 input->name = data->info->name; 385 input->id.bustype = BUS_I2C; 386 387 max_xy = data->info->max_xy; 388 input_set_abs_params(input, ABS_MT_POSITION_X, 0, max_xy, 0, 0); 389 input_set_abs_params(input, ABS_MT_POSITION_Y, 0, max_xy, 0, 0); 390 391 touchscreen_parse_properties(input, true, &data->prop); 392 393 error = input_mt_init_slots(input, EXC3000_NUM_SLOTS, 394 INPUT_MT_DIRECT | INPUT_MT_DROP_UNUSED); 395 if (error) 396 return error; 397 398 error = input_register_device(input); 399 if (error) 400 return error; 401 402 error = devm_add_action_or_reset(&client->dev, exc3000_shutdown_timer, 403 &data->timer); 404 if (error) 405 return error; 406 407 error = devm_request_threaded_irq(&client->dev, client->irq, 408 NULL, exc3000_interrupt, IRQF_ONESHOT, 409 client->name, data); 410 if (error) 411 return error; 412 413 /* 414 * I²C does not have built-in recovery, so retry on failure. This 415 * ensures, that the device probe will not fail for temporary issues 416 * on the bus. This is not needed for the sysfs calls (userspace 417 * will receive the error code and can start another query) and 418 * cannot be done for touch events (but that only means loosing one 419 * or two touch events anyways). 420 */ 421 for (retry = 0; retry < 3; retry++) { 422 u8 response[EXC3000_LEN_FRAME]; 423 424 error = exc3000_vendor_data_request(data, (u8[]){'E'}, 1, 425 response, 1); 426 if (error > 0) { 427 dev_dbg(&client->dev, "TS Model: %s", &response[1]); 428 error = 0; 429 break; 430 } 431 dev_warn(&client->dev, "Retry %d get EETI EXC3000 model: %d\n", 432 retry + 1, error); 433 } 434 435 if (error) 436 return error; 437 438 i2c_set_clientdata(client, data); 439 440 error = devm_device_add_group(&client->dev, &exc3000_attribute_group); 441 if (error) 442 return error; 443 444 return 0; 445 } 446 447 static const struct i2c_device_id exc3000_id[] = { 448 { "exc3000", EETI_EXC3000 }, 449 { "exc80h60", EETI_EXC80H60 }, 450 { "exc80h84", EETI_EXC80H84 }, 451 { } 452 }; 453 MODULE_DEVICE_TABLE(i2c, exc3000_id); 454 455 #ifdef CONFIG_OF 456 static const struct of_device_id exc3000_of_match[] = { 457 { .compatible = "eeti,exc3000", .data = &exc3000_info[EETI_EXC3000] }, 458 { .compatible = "eeti,exc80h60", .data = &exc3000_info[EETI_EXC80H60] }, 459 { .compatible = "eeti,exc80h84", .data = &exc3000_info[EETI_EXC80H84] }, 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 .of_match_table = of_match_ptr(exc3000_of_match), 477 .acpi_match_table = ACPI_PTR(exc3000_acpi_match), 478 }, 479 .id_table = exc3000_id, 480 .probe = exc3000_probe, 481 }; 482 483 module_i2c_driver(exc3000_driver); 484 485 MODULE_AUTHOR("Ahmet Inan <inan@distec.de>"); 486 MODULE_DESCRIPTION("I2C connected EETI EXC3000 multiple touch controller driver"); 487 MODULE_LICENSE("GPL v2"); 488