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 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 } 105 106 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 } 113 114 static inline void exc3000_schedule_timer(struct exc3000_data *data) 115 { 116 mod_timer(&data->timer, jiffies + msecs_to_jiffies(EXC3000_TIMEOUT_MS)); 117 } 118 119 static void exc3000_shutdown_timer(void *timer) 120 { 121 timer_shutdown_sync(timer); 122 } 123 124 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 } 148 149 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 } 198 199 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 } 229 230 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 } 270 271 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); 300 301 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); 316 317 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); 340 341 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