drivers/input/touchscreen/hycon-hy46xx.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (C) 2021
   4  * Author(s): Giulio Benetti <giulio.benetti@benettiengineering.com>
   5  */
   6
   7 #include <linux/delay.h>
   8 #include <linux/gpio/consumer.h>
   9 #include <linux/i2c.h>
  10 #include <linux/interrupt.h>
  11 #include <linux/input.h>
  12 #include <linux/input/mt.h>
  13 #include <linux/input/touchscreen.h>
  14 #include <linux/irq.h>
  15 #include <linux/regulator/consumer.h>
  16 #include <linux/regmap.h>
  17
  18 #include <linux/unaligned.h>
  19
  20 #define HY46XX_CHKSUM_CODE              0x1
  21 #define HY46XX_FINGER_NUM               0x2
  22 #define HY46XX_CHKSUM_LEN               0x7
  23 #define HY46XX_THRESHOLD                0x80
  24 #define HY46XX_GLOVE_EN                 0x84
  25 #define HY46XX_REPORT_SPEED             0x88
  26 #define HY46XX_PWR_NOISE_EN             0x89
  27 #define HY46XX_FILTER_DATA              0x8A
  28 #define HY46XX_GAIN                     0x92
  29 #define HY46XX_EDGE_OFFSET              0x93
  30 #define HY46XX_RX_NR_USED               0x94
  31 #define HY46XX_TX_NR_USED               0x95
  32 #define HY46XX_PWR_MODE                 0xA5
  33 #define HY46XX_FW_VERSION               0xA6
  34 #define HY46XX_LIB_VERSION              0xA7
  35 #define HY46XX_TP_INFO                  0xA8
  36 #define HY46XX_TP_CHIP_ID               0xA9
  37 #define HY46XX_BOOT_VER                 0xB0
  38
  39 #define HY46XX_TPLEN                    0x6
  40 #define HY46XX_REPORT_PKT_LEN           0x44
  41
  42 #define HY46XX_MAX_SUPPORTED_POINTS     11
  43
  44 #define TOUCH_EVENT_DOWN                0x00
  45 #define TOUCH_EVENT_UP                  0x01
  46 #define TOUCH_EVENT_CONTACT             0x02
  47 #define TOUCH_EVENT_RESERVED            0x03
  48
  49 struct hycon_hy46xx_data {
  50         struct i2c_client *client;
  51         struct input_dev *input;
  52         struct touchscreen_properties prop;
  53         struct regulator *vcc;
  54
  55         struct gpio_desc *reset_gpio;
  56
  57         struct mutex mutex;
  58         struct regmap *regmap;
  59
  60         int threshold;
  61         bool glove_enable;
  62         int report_speed;
  63         bool noise_filter_enable;
  64         int filter_data;
  65         int gain;
  66         int edge_offset;
  67         int rx_number_used;
  68         int tx_number_used;
  69         int power_mode;
  70         int fw_version;
  71         int lib_version;
  72         int tp_information;
  73         int tp_chip_id;
  74         int bootloader_version;
  75 };
  76
  77 static const struct regmap_config hycon_hy46xx_i2c_regmap_config = {
  78         .reg_bits = 8,
  79         .val_bits = 8,
  80 };
  81
  82 static bool hycon_hy46xx_check_checksum(struct hycon_hy46xx_data *tsdata, u8 *buf)
  83 {
  84         u8 chksum = 0;
  85         int i;
  86
  87         for (i = 2; i < buf[HY46XX_CHKSUM_LEN]; i++)
  88                 chksum += buf[i];
  89
  90         if (chksum == buf[HY46XX_CHKSUM_CODE])
  91                 return true;
  92
  93         dev_err_ratelimited(&tsdata->client->dev,
  94                             "checksum error: 0x%02x expected, got 0x%02x\n",
  95                             chksum, buf[HY46XX_CHKSUM_CODE]);
  96
  97         return false;
  98 }
  99
 100 static irqreturn_t hycon_hy46xx_isr(int irq, void *dev_id)
 101 {
 102         struct hycon_hy46xx_data *tsdata = dev_id;
 103         struct device *dev = &tsdata->client->dev;
 104         u8 rdbuf[HY46XX_REPORT_PKT_LEN];
 105         int i, x, y, id;
 106         int error;
 107
 108         memset(rdbuf, 0, sizeof(rdbuf));
 109
 110         error = regmap_bulk_read(tsdata->regmap, 0, rdbuf, sizeof(rdbuf));
 111         if (error) {
 112                 dev_err_ratelimited(dev, "Unable to fetch data, error: %d\n",
 113                                     error);
 114                 goto out;
 115         }
 116
 117         if (!hycon_hy46xx_check_checksum(tsdata, rdbuf))
 118                 goto out;
 119
 120         for (i = 0; i < HY46XX_MAX_SUPPORTED_POINTS; i++) {
 121                 u8 *buf = &rdbuf[3 + (HY46XX_TPLEN * i)];
 122                 int type = buf[0] >> 6;
 123
 124                 if (type == TOUCH_EVENT_RESERVED)
 125                         continue;
 126
 127                 x = get_unaligned_be16(buf) & 0x0fff;
 128                 y = get_unaligned_be16(buf + 2) & 0x0fff;
 129
 130                 id = buf[2] >> 4;
 131
 132                 input_mt_slot(tsdata->input, id);
 133                 if (input_mt_report_slot_state(tsdata->input, MT_TOOL_FINGER,
 134                                                type != TOUCH_EVENT_UP))
 135                         touchscreen_report_pos(tsdata->input, &tsdata->prop,
 136                                                x, y, true);
 137         }
 138
 139         input_mt_report_pointer_emulation(tsdata->input, false);
 140         input_sync(tsdata->input);
 141
 142 out:
 143         return IRQ_HANDLED;
 144 }
 145
 146 struct hycon_hy46xx_attribute {
 147         struct device_attribute dattr;
 148         size_t field_offset;
 149         u8 address;
 150         u8 limit_low;
 151         u8 limit_high;
 152 };
 153
 154 #define HYCON_ATTR_U8(_field, _mode, _address, _limit_low, _limit_high) \
 155         struct hycon_hy46xx_attribute hycon_hy46xx_attr_##_field = {            \
 156                 .dattr = __ATTR(_field, _mode,                          \
 157                                 hycon_hy46xx_setting_show,                      \
 158                                 hycon_hy46xx_setting_store),                    \
 159                 .field_offset = offsetof(struct hycon_hy46xx_data, _field),     \
 160                 .address = _address,                                    \
 161                 .limit_low = _limit_low,                                \
 162                 .limit_high = _limit_high,                              \
 163         }
 164
 165 #define HYCON_ATTR_BOOL(_field, _mode, _address)                        \
 166         struct hycon_hy46xx_attribute hycon_hy46xx_attr_##_field = {            \
 167                 .dattr = __ATTR(_field, _mode,                          \
 168                                 hycon_hy46xx_setting_show,                      \
 169                                 hycon_hy46xx_setting_store),                    \
 170                 .field_offset = offsetof(struct hycon_hy46xx_data, _field),     \
 171                 .address = _address,                                    \
 172                 .limit_low = false,                                     \
 173                 .limit_high = true,                                     \
 174         }
 175
 176 static ssize_t hycon_hy46xx_setting_show(struct device *dev,
 177                                    struct device_attribute *dattr, char *buf)
 178 {
 179         struct i2c_client *client = to_i2c_client(dev);
 180         struct hycon_hy46xx_data *tsdata = i2c_get_clientdata(client);
 181         struct hycon_hy46xx_attribute *attr =
 182                         container_of(dattr, struct hycon_hy46xx_attribute, dattr);
 183         u8 *field = (u8 *)tsdata + attr->field_offset;
 184         size_t count = 0;
 185         int error = 0;
 186         int val;
 187
 188         mutex_lock(&tsdata->mutex);
 189
 190         error = regmap_read(tsdata->regmap, attr->address, &val);
 191         if (error < 0) {
 192                 dev_err(&tsdata->client->dev,
 193                         "Failed to fetch attribute %s, error %d\n",
 194                         dattr->attr.name, error);
 195                 goto out;
 196         }
 197
 198         if (val != *field) {
 199                 dev_warn(&tsdata->client->dev,
 200                          "%s: read (%d) and stored value (%d) differ\n",
 201                          dattr->attr.name, val, *field);
 202                 *field = val;
 203         }
 204
 205         count = sysfs_emit(buf, "%d\n", val);
 206
 207 out:
 208         mutex_unlock(&tsdata->mutex);
 209         return error ?: count;
 210 }
 211
 212 static ssize_t hycon_hy46xx_setting_store(struct device *dev,
 213                                         struct device_attribute *dattr,
 214                                         const char *buf, size_t count)
 215 {
 216         struct i2c_client *client = to_i2c_client(dev);
 217         struct hycon_hy46xx_data *tsdata = i2c_get_clientdata(client);
 218         struct hycon_hy46xx_attribute *attr =
 219                         container_of(dattr, struct hycon_hy46xx_attribute, dattr);
 220         u8 *field = (u8 *)tsdata + attr->field_offset;
 221         unsigned int val;
 222         int error;
 223
 224         mutex_lock(&tsdata->mutex);
 225
 226         error = kstrtouint(buf, 0, &val);
 227         if (error)
 228                 goto out;
 229
 230         if (val < attr->limit_low || val > attr->limit_high) {
 231                 error = -ERANGE;
 232                 goto out;
 233         }
 234
 235         error = regmap_write(tsdata->regmap, attr->address, val);
 236         if (error < 0) {
 237                 dev_err(&tsdata->client->dev,
 238                         "Failed to update attribute %s, error: %d\n",
 239                         dattr->attr.name, error);
 240                 goto out;
 241         }
 242         *field = val;
 243
 244 out:
 245         mutex_unlock(&tsdata->mutex);
 246         return error ?: count;
 247 }
 248
 249 static HYCON_ATTR_U8(threshold, 0644, HY46XX_THRESHOLD, 0, 255);
 250 static HYCON_ATTR_BOOL(glove_enable, 0644, HY46XX_GLOVE_EN);
 251 static HYCON_ATTR_U8(report_speed, 0644, HY46XX_REPORT_SPEED, 0, 255);
 252 static HYCON_ATTR_BOOL(noise_filter_enable, 0644, HY46XX_PWR_NOISE_EN);
 253 static HYCON_ATTR_U8(filter_data, 0644, HY46XX_FILTER_DATA, 0, 5);
 254 static HYCON_ATTR_U8(gain, 0644, HY46XX_GAIN, 0, 5);
 255 static HYCON_ATTR_U8(edge_offset, 0644, HY46XX_EDGE_OFFSET, 0, 5);
 256 static HYCON_ATTR_U8(fw_version, 0444, HY46XX_FW_VERSION, 0, 255);
 257 static HYCON_ATTR_U8(lib_version, 0444, HY46XX_LIB_VERSION, 0, 255);
 258 static HYCON_ATTR_U8(tp_information, 0444, HY46XX_TP_INFO, 0, 255);
 259 static HYCON_ATTR_U8(tp_chip_id, 0444, HY46XX_TP_CHIP_ID, 0, 255);
 260 static HYCON_ATTR_U8(bootloader_version, 0444, HY46XX_BOOT_VER, 0, 255);
 261
 262 static struct attribute *hycon_hy46xx_attrs[] = {
 263         &hycon_hy46xx_attr_threshold.dattr.attr,
 264         &hycon_hy46xx_attr_glove_enable.dattr.attr,
 265         &hycon_hy46xx_attr_report_speed.dattr.attr,
 266         &hycon_hy46xx_attr_noise_filter_enable.dattr.attr,
 267         &hycon_hy46xx_attr_filter_data.dattr.attr,
 268         &hycon_hy46xx_attr_gain.dattr.attr,
 269         &hycon_hy46xx_attr_edge_offset.dattr.attr,
 270         &hycon_hy46xx_attr_fw_version.dattr.attr,
 271         &hycon_hy46xx_attr_lib_version.dattr.attr,
 272         &hycon_hy46xx_attr_tp_information.dattr.attr,
 273         &hycon_hy46xx_attr_tp_chip_id.dattr.attr,
 274         &hycon_hy46xx_attr_bootloader_version.dattr.attr,
 275         NULL
 276 };
 277 ATTRIBUTE_GROUPS(hycon_hy46xx);
 278
 279 static void hycon_hy46xx_get_defaults(struct device *dev, struct hycon_hy46xx_data *tsdata)
 280 {
 281         bool val_bool;
 282         int error;
 283         u32 val;
 284
 285         error = device_property_read_u32(dev, "hycon,threshold", &val);
 286         if (!error) {
 287                 error = regmap_write(tsdata->regmap, HY46XX_THRESHOLD, val);
 288                 if (error < 0)
 289                         goto out;
 290
 291                 tsdata->threshold = val;
 292         }
 293
 294         val_bool = device_property_read_bool(dev, "hycon,glove-enable");
 295         error = regmap_write(tsdata->regmap, HY46XX_GLOVE_EN, val_bool);
 296         if (error < 0)
 297                 goto out;
 298         tsdata->glove_enable = val_bool;
 299
 300         error = device_property_read_u32(dev, "hycon,report-speed-hz", &val);
 301         if (!error) {
 302                 error = regmap_write(tsdata->regmap, HY46XX_REPORT_SPEED, val);
 303                 if (error < 0)
 304                         goto out;
 305
 306                 tsdata->report_speed = val;
 307         }
 308
 309         val_bool = device_property_read_bool(dev, "hycon,noise-filter-enable");
 310         error = regmap_write(tsdata->regmap, HY46XX_PWR_NOISE_EN, val_bool);
 311         if (error < 0)
 312                 goto out;
 313         tsdata->noise_filter_enable = val_bool;
 314
 315         error = device_property_read_u32(dev, "hycon,filter-data", &val);
 316         if (!error) {
 317                 error = regmap_write(tsdata->regmap, HY46XX_FILTER_DATA, val);
 318                 if (error < 0)
 319                         goto out;
 320
 321                 tsdata->filter_data = val;
 322         }
 323
 324         error = device_property_read_u32(dev, "hycon,gain", &val);
 325         if (!error) {
 326                 error = regmap_write(tsdata->regmap, HY46XX_GAIN, val);
 327                 if (error < 0)
 328                         goto out;
 329
 330                 tsdata->gain = val;
 331         }
 332
 333         error = device_property_read_u32(dev, "hycon,edge-offset", &val);
 334         if (!error) {
 335                 error = regmap_write(tsdata->regmap, HY46XX_EDGE_OFFSET, val);
 336                 if (error < 0)
 337                         goto out;
 338
 339                 tsdata->edge_offset = val;
 340         }
 341
 342         return;
 343 out:
 344         dev_err(&tsdata->client->dev, "Failed to set default settings");
 345 }
 346
 347 static void hycon_hy46xx_get_parameters(struct hycon_hy46xx_data *tsdata)
 348 {
 349         int error;
 350         u32 val;
 351
 352         error = regmap_read(tsdata->regmap, HY46XX_THRESHOLD, &val);
 353         if (error < 0)
 354                 goto out;
 355         tsdata->threshold = val;
 356
 357         error = regmap_read(tsdata->regmap, HY46XX_GLOVE_EN, &val);
 358         if (error < 0)
 359                 goto out;
 360         tsdata->glove_enable = val;
 361
 362         error = regmap_read(tsdata->regmap, HY46XX_REPORT_SPEED, &val);
 363         if (error < 0)
 364                 goto out;
 365         tsdata->report_speed = val;
 366
 367         error = regmap_read(tsdata->regmap, HY46XX_PWR_NOISE_EN, &val);
 368         if (error < 0)
 369                 goto out;
 370         tsdata->noise_filter_enable = val;
 371
 372         error = regmap_read(tsdata->regmap, HY46XX_FILTER_DATA, &val);
 373         if (error < 0)
 374                 goto out;
 375         tsdata->filter_data = val;
 376
 377         error = regmap_read(tsdata->regmap, HY46XX_GAIN, &val);
 378         if (error < 0)
 379                 goto out;
 380         tsdata->gain = val;
 381
 382         error = regmap_read(tsdata->regmap, HY46XX_EDGE_OFFSET, &val);
 383         if (error < 0)
 384                 goto out;
 385         tsdata->edge_offset = val;
 386
 387         error = regmap_read(tsdata->regmap, HY46XX_RX_NR_USED, &val);
 388         if (error < 0)
 389                 goto out;
 390         tsdata->rx_number_used = val;
 391
 392         error = regmap_read(tsdata->regmap, HY46XX_TX_NR_USED, &val);
 393         if (error < 0)
 394                 goto out;
 395         tsdata->tx_number_used = val;
 396
 397         error = regmap_read(tsdata->regmap, HY46XX_PWR_MODE, &val);
 398         if (error < 0)
 399                 goto out;
 400         tsdata->power_mode = val;
 401
 402         error = regmap_read(tsdata->regmap, HY46XX_FW_VERSION, &val);
 403         if (error < 0)
 404                 goto out;
 405         tsdata->fw_version = val;
 406
 407         error = regmap_read(tsdata->regmap, HY46XX_LIB_VERSION, &val);
 408         if (error < 0)
 409                 goto out;
 410         tsdata->lib_version = val;
 411
 412         error = regmap_read(tsdata->regmap, HY46XX_TP_INFO, &val);
 413         if (error < 0)
 414                 goto out;
 415         tsdata->tp_information = val;
 416
 417         error = regmap_read(tsdata->regmap, HY46XX_TP_CHIP_ID, &val);
 418         if (error < 0)
 419                 goto out;
 420         tsdata->tp_chip_id = val;
 421
 422         error = regmap_read(tsdata->regmap, HY46XX_BOOT_VER, &val);
 423         if (error < 0)
 424                 goto out;
 425         tsdata->bootloader_version = val;
 426
 427         return;
 428 out:
 429         dev_err(&tsdata->client->dev, "Failed to read default settings");
 430 }
 431
 432 static void hycon_hy46xx_disable_regulator(void *arg)
 433 {
 434         struct hycon_hy46xx_data *data = arg;
 435
 436         regulator_disable(data->vcc);
 437 }
 438
 439 static int hycon_hy46xx_probe(struct i2c_client *client)
 440 {
 441         struct hycon_hy46xx_data *tsdata;
 442         struct input_dev *input;
 443         int error;
 444
 445         dev_dbg(&client->dev, "probing for HYCON HY46XX I2C\n");
 446
 447         tsdata = devm_kzalloc(&client->dev, sizeof(*tsdata), GFP_KERNEL);
 448         if (!tsdata)
 449                 return -ENOMEM;
 450
 451         tsdata->vcc = devm_regulator_get(&client->dev, "vcc");
 452         if (IS_ERR(tsdata->vcc)) {
 453                 error = PTR_ERR(tsdata->vcc);
 454                 if (error != -EPROBE_DEFER)
 455                         dev_err(&client->dev,
 456                                 "failed to request regulator: %d\n", error);
 457                 return error;
 458         }
 459
 460         error = regulator_enable(tsdata->vcc);
 461         if (error < 0) {
 462                 dev_err(&client->dev, "failed to enable vcc: %d\n", error);
 463                 return error;
 464         }
 465
 466         error = devm_add_action_or_reset(&client->dev,
 467                                          hycon_hy46xx_disable_regulator,
 468                                          tsdata);
 469         if (error)
 470                 return error;
 471
 472         tsdata->reset_gpio = devm_gpiod_get_optional(&client->dev,
 473                                                      "reset", GPIOD_OUT_LOW);
 474         if (IS_ERR(tsdata->reset_gpio)) {
 475                 error = PTR_ERR(tsdata->reset_gpio);
 476                 dev_err(&client->dev,
 477                         "Failed to request GPIO reset pin, error %d\n", error);
 478                 return error;
 479         }
 480
 481         if (tsdata->reset_gpio) {
 482                 usleep_range(5000, 6000);
 483                 gpiod_set_value_cansleep(tsdata->reset_gpio, 1);
 484                 usleep_range(5000, 6000);
 485                 gpiod_set_value_cansleep(tsdata->reset_gpio, 0);
 486                 msleep(1000);
 487         }
 488
 489         input = devm_input_allocate_device(&client->dev);
 490         if (!input) {
 491                 dev_err(&client->dev, "failed to allocate input device.\n");
 492                 return -ENOMEM;
 493         }
 494
 495         mutex_init(&tsdata->mutex);
 496         tsdata->client = client;
 497         tsdata->input = input;
 498
 499         tsdata->regmap = devm_regmap_init_i2c(client,
 500                                               &hycon_hy46xx_i2c_regmap_config);
 501         if (IS_ERR(tsdata->regmap)) {
 502                 dev_err(&client->dev, "regmap allocation failed\n");
 503                 return PTR_ERR(tsdata->regmap);
 504         }
 505
 506         hycon_hy46xx_get_defaults(&client->dev, tsdata);
 507         hycon_hy46xx_get_parameters(tsdata);
 508
 509         input->name = "Hycon Capacitive Touch";
 510         input->id.bustype = BUS_I2C;
 511         input->dev.parent = &client->dev;
 512
 513         input_set_abs_params(input, ABS_MT_POSITION_X, 0, -1, 0, 0);
 514         input_set_abs_params(input, ABS_MT_POSITION_Y, 0, -1, 0, 0);
 515
 516         touchscreen_parse_properties(input, true, &tsdata->prop);
 517
 518         error = input_mt_init_slots(input, HY46XX_MAX_SUPPORTED_POINTS,
 519                                     INPUT_MT_DIRECT);
 520         if (error) {
 521                 dev_err(&client->dev, "Unable to init MT slots.\n");
 522                 return error;
 523         }
 524
 525         i2c_set_clientdata(client, tsdata);
 526
 527         error = devm_request_threaded_irq(&client->dev, client->irq,
 528                                           NULL, hycon_hy46xx_isr, IRQF_ONESHOT,
 529                                           client->name, tsdata);
 530         if (error) {
 531                 dev_err(&client->dev, "Unable to request touchscreen IRQ.\n");
 532                 return error;
 533         }
 534
 535         error = input_register_device(input);
 536         if (error)
 537                 return error;
 538
 539         dev_dbg(&client->dev,
 540                 "HYCON HY46XX initialized: IRQ %d, Reset pin %d.\n",
 541                 client->irq,
 542                 tsdata->reset_gpio ? desc_to_gpio(tsdata->reset_gpio) : -1);
 543
 544         return 0;
 545 }
 546
 547 static const struct i2c_device_id hycon_hy46xx_id[] = {
 548         { .name = "hy4613" },
 549         { .name = "hy4614" },
 550         { .name = "hy4621" },
 551         { .name = "hy4623" },
 552         { .name = "hy4633" },
 553         { .name = "hy4635" },
 554         { /* sentinel */ }
 555 };
 556 MODULE_DEVICE_TABLE(i2c, hycon_hy46xx_id);
 557
 558 static const struct of_device_id hycon_hy46xx_of_match[] = {
 559         { .compatible = "hycon,hy4613" },
 560         { .compatible = "hycon,hy4614" },
 561         { .compatible = "hycon,hy4621" },
 562         { .compatible = "hycon,hy4623" },
 563         { .compatible = "hycon,hy4633" },
 564         { .compatible = "hycon,hy4635" },
 565         { /* sentinel */ }
 566 };
 567 MODULE_DEVICE_TABLE(of, hycon_hy46xx_of_match);
 568
 569 static struct i2c_driver hycon_hy46xx_driver = {
 570         .driver = {
 571                 .name = "hycon_hy46xx",
 572                 .dev_groups = hycon_hy46xx_groups,
 573                 .of_match_table = hycon_hy46xx_of_match,
 574                 .probe_type = PROBE_PREFER_ASYNCHRONOUS,
 575         },
 576         .id_table = hycon_hy46xx_id,
 577         .probe = hycon_hy46xx_probe,
 578 };
 579
 580 module_i2c_driver(hycon_hy46xx_driver);
 581
 582 MODULE_AUTHOR("Giulio Benetti <giulio.benetti@benettiengineering.com>");
 583 MODULE_DESCRIPTION("HYCON HY46XX I2C Touchscreen Driver");
 584 MODULE_LICENSE("GPL v2");