1 // SPDX-License-Identifier: GPL-2.0-only 2 3 #include <linux/delay.h> 4 #include <linux/i2c.h> 5 #include <linux/input.h> 6 #include <linux/input/mt.h> 7 #include <linux/input/touchscreen.h> 8 #include <linux/interrupt.h> 9 #include <linux/irq.h> 10 #include <linux/kernel.h> 11 #include <linux/module.h> 12 #include <linux/of.h> 13 #include <linux/regulator/consumer.h> 14 #include <linux/slab.h> 15 16 /* Register Map */ 17 18 #define BT541_SWRESET_CMD 0x0000 19 #define BT541_WAKEUP_CMD 0x0001 20 21 #define BT541_IDLE_CMD 0x0004 22 #define BT541_SLEEP_CMD 0x0005 23 24 #define BT541_CLEAR_INT_STATUS_CMD 0x0003 25 #define BT541_CALIBRATE_CMD 0x0006 26 #define BT541_SAVE_STATUS_CMD 0x0007 27 #define BT541_SAVE_CALIBRATION_CMD 0x0008 28 #define BT541_RECALL_FACTORY_CMD 0x000f 29 30 #define BT541_THRESHOLD 0x0020 31 32 #define BT541_LARGE_PALM_REJECT_AREA_TH 0x003F 33 34 #define BT541_DEBUG_REG 0x0115 /* 0~7 */ 35 36 #define BT541_TOUCH_MODE 0x0010 37 #define BT541_CHIP_REVISION 0x0011 38 #define BT541_FIRMWARE_VERSION 0x0012 39 40 #define ZINITIX_USB_DETECT 0x116 41 42 #define BT541_MINOR_FW_VERSION 0x0121 43 44 #define BT541_VENDOR_ID 0x001C 45 #define BT541_HW_ID 0x0014 46 47 #define BT541_DATA_VERSION_REG 0x0013 48 #define BT541_SUPPORTED_FINGER_NUM 0x0015 49 #define BT541_EEPROM_INFO 0x0018 50 #define BT541_INITIAL_TOUCH_MODE 0x0019 51 52 #define BT541_TOTAL_NUMBER_OF_X 0x0060 53 #define BT541_TOTAL_NUMBER_OF_Y 0x0061 54 55 #define BT541_DELAY_RAW_FOR_HOST 0x007f 56 57 #define BT541_BUTTON_SUPPORTED_NUM 0x00B0 58 #define BT541_BUTTON_SENSITIVITY 0x00B2 59 #define BT541_DUMMY_BUTTON_SENSITIVITY 0X00C8 60 61 #define BT541_X_RESOLUTION 0x00C0 62 #define BT541_Y_RESOLUTION 0x00C1 63 64 #define BT541_POINT_STATUS_REG 0x0080 65 #define BT541_ICON_STATUS_REG 0x00AA 66 67 #define BT541_POINT_COORD_REG (BT541_POINT_STATUS_REG + 2) 68 69 #define BT541_AFE_FREQUENCY 0x0100 70 #define BT541_DND_N_COUNT 0x0122 71 #define BT541_DND_U_COUNT 0x0135 72 73 #define BT541_RAWDATA_REG 0x0200 74 75 #define BT541_EEPROM_INFO_REG 0x0018 76 77 #define BT541_INT_ENABLE_FLAG 0x00f0 78 #define BT541_PERIODICAL_INTERRUPT_INTERVAL 0x00f1 79 80 #define BT541_BTN_WIDTH 0x016d 81 82 #define BT541_CHECKSUM_RESULT 0x012c 83 84 #define BT541_INIT_FLASH 0x01d0 85 #define BT541_WRITE_FLASH 0x01d1 86 #define BT541_READ_FLASH 0x01d2 87 88 #define ZINITIX_INTERNAL_FLAG_02 0x011e 89 #define ZINITIX_INTERNAL_FLAG_03 0x011f 90 91 #define ZINITIX_I2C_CHECKSUM_WCNT 0x016a 92 #define ZINITIX_I2C_CHECKSUM_RESULT 0x016c 93 94 /* Interrupt & status register flags */ 95 96 #define BIT_PT_CNT_CHANGE BIT(0) 97 #define BIT_DOWN BIT(1) 98 #define BIT_MOVE BIT(2) 99 #define BIT_UP BIT(3) 100 #define BIT_PALM BIT(4) 101 #define BIT_PALM_REJECT BIT(5) 102 #define BIT_RESERVED_0 BIT(6) 103 #define BIT_RESERVED_1 BIT(7) 104 #define BIT_WEIGHT_CHANGE BIT(8) 105 #define BIT_PT_NO_CHANGE BIT(9) 106 #define BIT_REJECT BIT(10) 107 #define BIT_PT_EXIST BIT(11) 108 #define BIT_RESERVED_2 BIT(12) 109 #define BIT_ERROR BIT(13) 110 #define BIT_DEBUG BIT(14) 111 #define BIT_ICON_EVENT BIT(15) 112 113 #define SUB_BIT_EXIST BIT(0) 114 #define SUB_BIT_DOWN BIT(1) 115 #define SUB_BIT_MOVE BIT(2) 116 #define SUB_BIT_UP BIT(3) 117 #define SUB_BIT_UPDATE BIT(4) 118 #define SUB_BIT_WAIT BIT(5) 119 120 #define DEFAULT_TOUCH_POINT_MODE 2 121 #define MAX_SUPPORTED_FINGER_NUM 5 122 123 #define CHIP_ON_DELAY 15 // ms 124 #define FIRMWARE_ON_DELAY 40 // ms 125 126 struct point_coord { 127 __le16 x; 128 __le16 y; 129 u8 width; 130 u8 sub_status; 131 // currently unused, but needed as padding: 132 u8 minor_width; 133 u8 angle; 134 }; 135 136 struct touch_event { 137 __le16 status; 138 u8 finger_cnt; 139 u8 time_stamp; 140 struct point_coord point_coord[MAX_SUPPORTED_FINGER_NUM]; 141 }; 142 143 struct bt541_ts_data { 144 struct i2c_client *client; 145 struct input_dev *input_dev; 146 struct touchscreen_properties prop; 147 struct regulator_bulk_data supplies[2]; 148 u32 zinitix_mode; 149 }; 150 151 static int zinitix_read_data(struct i2c_client *client, 152 u16 reg, void *values, size_t length) 153 { 154 __le16 reg_le = cpu_to_le16(reg); 155 int ret; 156 157 /* A single i2c_transfer() transaction does not work here. */ 158 ret = i2c_master_send(client, (u8 *)®_le, sizeof(reg_le)); 159 if (ret != sizeof(reg_le)) 160 return ret < 0 ? ret : -EIO; 161 162 ret = i2c_master_recv(client, (u8 *)values, length); 163 if (ret != length) 164 return ret < 0 ? ret : -EIO; ; 165 166 return 0; 167 } 168 169 static int zinitix_write_u16(struct i2c_client *client, u16 reg, u16 value) 170 { 171 __le16 packet[2] = {cpu_to_le16(reg), cpu_to_le16(value)}; 172 int ret; 173 174 ret = i2c_master_send(client, (u8 *)packet, sizeof(packet)); 175 if (ret != sizeof(packet)) 176 return ret < 0 ? ret : -EIO; 177 178 return 0; 179 } 180 181 static int zinitix_write_cmd(struct i2c_client *client, u16 reg) 182 { 183 __le16 reg_le = cpu_to_le16(reg); 184 int ret; 185 186 ret = i2c_master_send(client, (u8 *)®_le, sizeof(reg_le)); 187 if (ret != sizeof(reg_le)) 188 return ret < 0 ? ret : -EIO; 189 190 return 0; 191 } 192 193 static bool zinitix_init_touch(struct bt541_ts_data *bt541) 194 { 195 struct i2c_client *client = bt541->client; 196 int i; 197 int error; 198 199 error = zinitix_write_cmd(client, BT541_SWRESET_CMD); 200 if (error) { 201 dev_err(&client->dev, "Failed to write reset command\n"); 202 return error; 203 } 204 205 error = zinitix_write_u16(client, BT541_INT_ENABLE_FLAG, 0x0); 206 if (error) { 207 dev_err(&client->dev, 208 "Failed to reset interrupt enable flag\n"); 209 return error; 210 } 211 212 /* initialize */ 213 error = zinitix_write_u16(client, BT541_X_RESOLUTION, 214 bt541->prop.max_x); 215 if (error) 216 return error; 217 218 error = zinitix_write_u16(client, BT541_Y_RESOLUTION, 219 bt541->prop.max_y); 220 if (error) 221 return error; 222 223 error = zinitix_write_u16(client, BT541_SUPPORTED_FINGER_NUM, 224 MAX_SUPPORTED_FINGER_NUM); 225 if (error) 226 return error; 227 228 error = zinitix_write_u16(client, BT541_INITIAL_TOUCH_MODE, 229 bt541->zinitix_mode); 230 if (error) 231 return error; 232 233 error = zinitix_write_u16(client, BT541_TOUCH_MODE, 234 bt541->zinitix_mode); 235 if (error) 236 return error; 237 238 error = zinitix_write_u16(client, BT541_INT_ENABLE_FLAG, 239 BIT_PT_CNT_CHANGE | BIT_DOWN | BIT_MOVE | 240 BIT_UP); 241 if (error) 242 return error; 243 244 /* clear queue */ 245 for (i = 0; i < 10; i++) { 246 zinitix_write_cmd(client, BT541_CLEAR_INT_STATUS_CMD); 247 udelay(10); 248 } 249 250 return 0; 251 } 252 253 static int zinitix_init_regulators(struct bt541_ts_data *bt541) 254 { 255 struct i2c_client *client = bt541->client; 256 int error; 257 258 bt541->supplies[0].supply = "vdd"; 259 bt541->supplies[1].supply = "vddo"; 260 error = devm_regulator_bulk_get(&client->dev, 261 ARRAY_SIZE(bt541->supplies), 262 bt541->supplies); 263 if (error < 0) { 264 dev_err(&client->dev, "Failed to get regulators: %d\n", error); 265 return error; 266 } 267 268 return 0; 269 } 270 271 static int zinitix_send_power_on_sequence(struct bt541_ts_data *bt541) 272 { 273 int error; 274 struct i2c_client *client = bt541->client; 275 276 error = zinitix_write_u16(client, 0xc000, 0x0001); 277 if (error) { 278 dev_err(&client->dev, 279 "Failed to send power sequence(vendor cmd enable)\n"); 280 return error; 281 } 282 udelay(10); 283 284 error = zinitix_write_cmd(client, 0xc004); 285 if (error) { 286 dev_err(&client->dev, 287 "Failed to send power sequence (intn clear)\n"); 288 return error; 289 } 290 udelay(10); 291 292 error = zinitix_write_u16(client, 0xc002, 0x0001); 293 if (error) { 294 dev_err(&client->dev, 295 "Failed to send power sequence (nvm init)\n"); 296 return error; 297 } 298 mdelay(2); 299 300 error = zinitix_write_u16(client, 0xc001, 0x0001); 301 if (error) { 302 dev_err(&client->dev, 303 "Failed to send power sequence (program start)\n"); 304 return error; 305 } 306 msleep(FIRMWARE_ON_DELAY); 307 308 return 0; 309 } 310 311 static void zinitix_report_finger(struct bt541_ts_data *bt541, int slot, 312 const struct point_coord *p) 313 { 314 input_mt_slot(bt541->input_dev, slot); 315 input_mt_report_slot_state(bt541->input_dev, MT_TOOL_FINGER, true); 316 touchscreen_report_pos(bt541->input_dev, &bt541->prop, 317 le16_to_cpu(p->x), le16_to_cpu(p->y), true); 318 input_report_abs(bt541->input_dev, ABS_MT_TOUCH_MAJOR, p->width); 319 } 320 321 static irqreturn_t zinitix_ts_irq_handler(int irq, void *bt541_handler) 322 { 323 struct bt541_ts_data *bt541 = bt541_handler; 324 struct i2c_client *client = bt541->client; 325 struct touch_event touch_event; 326 int error; 327 int i; 328 329 memset(&touch_event, 0, sizeof(struct touch_event)); 330 331 error = zinitix_read_data(bt541->client, BT541_POINT_STATUS_REG, 332 &touch_event, sizeof(struct touch_event)); 333 if (error) { 334 dev_err(&client->dev, "Failed to read in touchpoint struct\n"); 335 goto out; 336 } 337 338 for (i = 0; i < MAX_SUPPORTED_FINGER_NUM; i++) 339 if (touch_event.point_coord[i].sub_status & SUB_BIT_EXIST) 340 zinitix_report_finger(bt541, i, 341 &touch_event.point_coord[i]); 342 343 input_mt_sync_frame(bt541->input_dev); 344 input_sync(bt541->input_dev); 345 346 out: 347 zinitix_write_cmd(bt541->client, BT541_CLEAR_INT_STATUS_CMD); 348 return IRQ_HANDLED; 349 } 350 351 static int zinitix_start(struct bt541_ts_data *bt541) 352 { 353 int error; 354 355 error = regulator_bulk_enable(ARRAY_SIZE(bt541->supplies), 356 bt541->supplies); 357 if (error) { 358 dev_err(&bt541->client->dev, 359 "Failed to enable regulators: %d\n", error); 360 return error; 361 } 362 363 msleep(CHIP_ON_DELAY); 364 365 error = zinitix_send_power_on_sequence(bt541); 366 if (error) { 367 dev_err(&bt541->client->dev, 368 "Error while sending power-on sequence: %d\n", error); 369 return error; 370 } 371 372 error = zinitix_init_touch(bt541); 373 if (error) { 374 dev_err(&bt541->client->dev, 375 "Error while configuring touch IC\n"); 376 return error; 377 } 378 379 enable_irq(bt541->client->irq); 380 381 return 0; 382 } 383 384 static int zinitix_stop(struct bt541_ts_data *bt541) 385 { 386 int error; 387 388 disable_irq(bt541->client->irq); 389 390 error = regulator_bulk_disable(ARRAY_SIZE(bt541->supplies), 391 bt541->supplies); 392 if (error) { 393 dev_err(&bt541->client->dev, 394 "Failed to disable regulators: %d\n", error); 395 return error; 396 } 397 398 return 0; 399 } 400 401 static int zinitix_input_open(struct input_dev *dev) 402 { 403 struct bt541_ts_data *bt541 = input_get_drvdata(dev); 404 405 return zinitix_start(bt541); 406 } 407 408 static void zinitix_input_close(struct input_dev *dev) 409 { 410 struct bt541_ts_data *bt541 = input_get_drvdata(dev); 411 412 zinitix_stop(bt541); 413 } 414 415 static int zinitix_init_input_dev(struct bt541_ts_data *bt541) 416 { 417 struct input_dev *input_dev; 418 int error; 419 420 input_dev = devm_input_allocate_device(&bt541->client->dev); 421 if (!input_dev) { 422 dev_err(&bt541->client->dev, 423 "Failed to allocate input device."); 424 return -ENOMEM; 425 } 426 427 input_set_drvdata(input_dev, bt541); 428 bt541->input_dev = input_dev; 429 430 input_dev->name = "Zinitix Capacitive TouchScreen"; 431 input_dev->phys = "input/ts"; 432 input_dev->id.bustype = BUS_I2C; 433 input_dev->open = zinitix_input_open; 434 input_dev->close = zinitix_input_close; 435 436 input_set_capability(input_dev, EV_ABS, ABS_MT_POSITION_X); 437 input_set_capability(input_dev, EV_ABS, ABS_MT_POSITION_Y); 438 input_set_abs_params(input_dev, ABS_MT_WIDTH_MAJOR, 0, 255, 0, 0); 439 input_set_abs_params(input_dev, ABS_MT_TOUCH_MAJOR, 0, 255, 0, 0); 440 441 touchscreen_parse_properties(input_dev, true, &bt541->prop); 442 if (!bt541->prop.max_x || !bt541->prop.max_y) { 443 dev_err(&bt541->client->dev, 444 "Touchscreen-size-x and/or touchscreen-size-y not set in dts\n"); 445 return -EINVAL; 446 } 447 448 error = input_mt_init_slots(input_dev, MAX_SUPPORTED_FINGER_NUM, 449 INPUT_MT_DIRECT | INPUT_MT_DROP_UNUSED); 450 if (error) { 451 dev_err(&bt541->client->dev, 452 "Failed to initialize MT slots: %d", error); 453 return error; 454 } 455 456 error = input_register_device(input_dev); 457 if (error) { 458 dev_err(&bt541->client->dev, 459 "Failed to register input device: %d", error); 460 return error; 461 } 462 463 return 0; 464 } 465 466 static int zinitix_ts_probe(struct i2c_client *client) 467 { 468 struct bt541_ts_data *bt541; 469 int error; 470 471 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) { 472 dev_err(&client->dev, 473 "Failed to assert adapter's support for plain I2C.\n"); 474 return -ENXIO; 475 } 476 477 bt541 = devm_kzalloc(&client->dev, sizeof(*bt541), GFP_KERNEL); 478 if (!bt541) 479 return -ENOMEM; 480 481 bt541->client = client; 482 i2c_set_clientdata(client, bt541); 483 484 error = zinitix_init_regulators(bt541); 485 if (error) { 486 dev_err(&client->dev, 487 "Failed to initialize regulators: %d\n", error); 488 return error; 489 } 490 491 error = zinitix_init_input_dev(bt541); 492 if (error) { 493 dev_err(&client->dev, 494 "Failed to initialize input device: %d\n", error); 495 return error; 496 } 497 498 error = device_property_read_u32(&client->dev, "zinitix,mode", 499 &bt541->zinitix_mode); 500 if (error < 0) { 501 /* fall back to mode 2 */ 502 bt541->zinitix_mode = DEFAULT_TOUCH_POINT_MODE; 503 } 504 505 if (bt541->zinitix_mode != 2) { 506 /* 507 * If there are devices that don't support mode 2, support 508 * for other modes (0, 1) will be needed. 509 */ 510 dev_err(&client->dev, 511 "Malformed zinitix,mode property, must be 2 (supplied: %d)\n", 512 bt541->zinitix_mode); 513 return -EINVAL; 514 } 515 516 irq_set_status_flags(client->irq, IRQ_NOAUTOEN); 517 error = devm_request_threaded_irq(&client->dev, client->irq, 518 NULL, zinitix_ts_irq_handler, 519 IRQF_ONESHOT, client->name, bt541); 520 if (error) { 521 dev_err(&client->dev, "Failed to request IRQ: %d\n", error); 522 return error; 523 } 524 525 return 0; 526 } 527 528 static int __maybe_unused zinitix_suspend(struct device *dev) 529 { 530 struct i2c_client *client = to_i2c_client(dev); 531 struct bt541_ts_data *bt541 = i2c_get_clientdata(client); 532 533 mutex_lock(&bt541->input_dev->mutex); 534 535 if (input_device_enabled(bt541->input_dev)) 536 zinitix_stop(bt541); 537 538 mutex_unlock(&bt541->input_dev->mutex); 539 540 return 0; 541 } 542 543 static int __maybe_unused zinitix_resume(struct device *dev) 544 { 545 struct i2c_client *client = to_i2c_client(dev); 546 struct bt541_ts_data *bt541 = i2c_get_clientdata(client); 547 int ret = 0; 548 549 mutex_lock(&bt541->input_dev->mutex); 550 551 if (input_device_enabled(bt541->input_dev)) 552 ret = zinitix_start(bt541); 553 554 mutex_unlock(&bt541->input_dev->mutex); 555 556 return ret; 557 } 558 559 static SIMPLE_DEV_PM_OPS(zinitix_pm_ops, zinitix_suspend, zinitix_resume); 560 561 #ifdef CONFIG_OF 562 static const struct of_device_id zinitix_of_match[] = { 563 { .compatible = "zinitix,bt541" }, 564 { } 565 }; 566 MODULE_DEVICE_TABLE(of, zinitix_of_match); 567 #endif 568 569 static struct i2c_driver zinitix_ts_driver = { 570 .probe_new = zinitix_ts_probe, 571 .driver = { 572 .name = "Zinitix-TS", 573 .pm = &zinitix_pm_ops, 574 .of_match_table = of_match_ptr(zinitix_of_match), 575 }, 576 }; 577 module_i2c_driver(zinitix_ts_driver); 578 579 MODULE_AUTHOR("Michael Srba <Michael.Srba@seznam.cz>"); 580 MODULE_DESCRIPTION("Zinitix touchscreen driver"); 581 MODULE_LICENSE("GPL v2"); 582