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Input: add zinitix touchscreen driver

Add support for the bt541 touchscreen IC from zinitix, loosely based on
downstream driver. The driver currently supports multitouch (5 touch points).
The bt541 seems to support touch keys, but the support was not added because
that functionality is not being utilized by the touchscreen used for testing.
Based on the similartities between downstream drivers, it seems likely that
other similar touchscreen ICs can be supported with this driver in the future.

Signed-off-by: Michael Srba <Michael.Srba@seznam.cz>
Link: https://lore.kernel.org/r/20201001122949.16846-1-michael.srba@seznam.cz
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

authored by

Michael Srba and committed by
Dmitry Torokhov
26822652 8f445ffa

+594
+12
drivers/input/touchscreen/Kconfig
··· 1322 1322 To compile this driver as a module, choose M here: the 1323 1323 module will be called iqs5xx. 1324 1324 1325 + config TOUCHSCREEN_ZINITIX 1326 + tristate "Zinitix touchscreen support" 1327 + depends on I2C 1328 + help 1329 + Say Y here if you have a touchscreen using Zinitix bt541, 1330 + or something similar enough. 1331 + 1332 + If unsure, say N. 1333 + 1334 + To compile this driver as a module, choose M here: the 1335 + module will be called zinitix. 1336 + 1325 1337 endif
+1
drivers/input/touchscreen/Makefile
··· 111 111 obj-$(CONFIG_TOUCHSCREEN_ROHM_BU21023) += rohm_bu21023.o 112 112 obj-$(CONFIG_TOUCHSCREEN_RASPBERRYPI_FW) += raspberrypi-ts.o 113 113 obj-$(CONFIG_TOUCHSCREEN_IQS5XX) += iqs5xx.o 114 + obj-$(CONFIG_TOUCHSCREEN_ZINITIX) += zinitix.o
+581
drivers/input/touchscreen/zinitix.c
··· 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 *)&reg_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 *)&reg_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 (bt541->input_dev->users) 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 (bt541->input_dev->users) 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");