linux/drivers/input/touchscreen/hycon-hy46xx.c
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   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 <asm/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
  49struct 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
  77static const struct regmap_config hycon_hy46xx_i2c_regmap_config = {
  78        .reg_bits = 8,
  79        .val_bits = 8,
  80};
  81
  82static 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
 100static 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
 142out:
 143        return IRQ_HANDLED;
 144}
 145
 146struct 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
 176static 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 = scnprintf(buf, PAGE_SIZE, "%d\n", val);
 206
 207out:
 208        mutex_unlock(&tsdata->mutex);
 209        return error ?: count;
 210}
 211
 212static 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
 244out:
 245        mutex_unlock(&tsdata->mutex);
 246        return error ?: count;
 247}
 248
 249static HYCON_ATTR_U8(threshold, 0644, HY46XX_THRESHOLD, 0, 255);
 250static HYCON_ATTR_BOOL(glove_enable, 0644, HY46XX_GLOVE_EN);
 251static HYCON_ATTR_U8(report_speed, 0644, HY46XX_REPORT_SPEED, 0, 255);
 252static HYCON_ATTR_BOOL(noise_filter_enable, 0644, HY46XX_PWR_NOISE_EN);
 253static HYCON_ATTR_U8(filter_data, 0644, HY46XX_FILTER_DATA, 0, 5);
 254static HYCON_ATTR_U8(gain, 0644, HY46XX_GAIN, 0, 5);
 255static HYCON_ATTR_U8(edge_offset, 0644, HY46XX_EDGE_OFFSET, 0, 5);
 256static HYCON_ATTR_U8(fw_version, 0444, HY46XX_FW_VERSION, 0, 255);
 257static HYCON_ATTR_U8(lib_version, 0444, HY46XX_LIB_VERSION, 0, 255);
 258static HYCON_ATTR_U8(tp_information, 0444, HY46XX_TP_INFO, 0, 255);
 259static HYCON_ATTR_U8(tp_chip_id, 0444, HY46XX_TP_CHIP_ID, 0, 255);
 260static HYCON_ATTR_U8(bootloader_version, 0444, HY46XX_BOOT_VER, 0, 255);
 261
 262static 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
 278static const struct attribute_group hycon_hy46xx_attr_group = {
 279        .attrs = hycon_hy46xx_attrs,
 280};
 281
 282static void hycon_hy46xx_get_defaults(struct device *dev, struct hycon_hy46xx_data *tsdata)
 283{
 284        bool val_bool;
 285        int error;
 286        u32 val;
 287
 288        error = device_property_read_u32(dev, "hycon,threshold", &val);
 289        if (!error) {
 290                error = regmap_write(tsdata->regmap, HY46XX_THRESHOLD, val);
 291                if (error < 0)
 292                        goto out;
 293
 294                tsdata->threshold = val;
 295        }
 296
 297        val_bool = device_property_read_bool(dev, "hycon,glove-enable");
 298        error = regmap_write(tsdata->regmap, HY46XX_GLOVE_EN, val_bool);
 299        if (error < 0)
 300                goto out;
 301        tsdata->glove_enable = val_bool;
 302
 303        error = device_property_read_u32(dev, "hycon,report-speed-hz", &val);
 304        if (!error) {
 305                error = regmap_write(tsdata->regmap, HY46XX_REPORT_SPEED, val);
 306                if (error < 0)
 307                        goto out;
 308
 309                tsdata->report_speed = val;
 310        }
 311
 312        val_bool = device_property_read_bool(dev, "hycon,noise-filter-enable");
 313        error = regmap_write(tsdata->regmap, HY46XX_PWR_NOISE_EN, val_bool);
 314        if (error < 0)
 315                goto out;
 316        tsdata->noise_filter_enable = val_bool;
 317
 318        error = device_property_read_u32(dev, "hycon,filter-data", &val);
 319        if (!error) {
 320                error = regmap_write(tsdata->regmap, HY46XX_FILTER_DATA, val);
 321                if (error < 0)
 322                        goto out;
 323
 324                tsdata->filter_data = val;
 325        }
 326
 327        error = device_property_read_u32(dev, "hycon,gain", &val);
 328        if (!error) {
 329                error = regmap_write(tsdata->regmap, HY46XX_GAIN, val);
 330                if (error < 0)
 331                        goto out;
 332
 333                tsdata->gain = val;
 334        }
 335
 336        error = device_property_read_u32(dev, "hycon,edge-offset", &val);
 337        if (!error) {
 338                error = regmap_write(tsdata->regmap, HY46XX_EDGE_OFFSET, val);
 339                if (error < 0)
 340                        goto out;
 341
 342                tsdata->edge_offset = val;
 343        }
 344
 345        return;
 346out:
 347        dev_err(&tsdata->client->dev, "Failed to set default settings");
 348}
 349
 350static void hycon_hy46xx_get_parameters(struct hycon_hy46xx_data *tsdata)
 351{
 352        int error;
 353        u32 val;
 354
 355        error = regmap_read(tsdata->regmap, HY46XX_THRESHOLD, &val);
 356        if (error < 0)
 357                goto out;
 358        tsdata->threshold = val;
 359
 360        error = regmap_read(tsdata->regmap, HY46XX_GLOVE_EN, &val);
 361        if (error < 0)
 362                goto out;
 363        tsdata->glove_enable = val;
 364
 365        error = regmap_read(tsdata->regmap, HY46XX_REPORT_SPEED, &val);
 366        if (error < 0)
 367                goto out;
 368        tsdata->report_speed = val;
 369
 370        error = regmap_read(tsdata->regmap, HY46XX_PWR_NOISE_EN, &val);
 371        if (error < 0)
 372                goto out;
 373        tsdata->noise_filter_enable = val;
 374
 375        error = regmap_read(tsdata->regmap, HY46XX_FILTER_DATA, &val);
 376        if (error < 0)
 377                goto out;
 378        tsdata->filter_data = val;
 379
 380        error = regmap_read(tsdata->regmap, HY46XX_GAIN, &val);
 381        if (error < 0)
 382                goto out;
 383        tsdata->gain = val;
 384
 385        error = regmap_read(tsdata->regmap, HY46XX_EDGE_OFFSET, &val);
 386        if (error < 0)
 387                goto out;
 388        tsdata->edge_offset = val;
 389
 390        error = regmap_read(tsdata->regmap, HY46XX_RX_NR_USED, &val);
 391        if (error < 0)
 392                goto out;
 393        tsdata->rx_number_used = val;
 394
 395        error = regmap_read(tsdata->regmap, HY46XX_TX_NR_USED, &val);
 396        if (error < 0)
 397                goto out;
 398        tsdata->tx_number_used = val;
 399
 400        error = regmap_read(tsdata->regmap, HY46XX_PWR_MODE, &val);
 401        if (error < 0)
 402                goto out;
 403        tsdata->power_mode = val;
 404
 405        error = regmap_read(tsdata->regmap, HY46XX_FW_VERSION, &val);
 406        if (error < 0)
 407                goto out;
 408        tsdata->fw_version = val;
 409
 410        error = regmap_read(tsdata->regmap, HY46XX_LIB_VERSION, &val);
 411        if (error < 0)
 412                goto out;
 413        tsdata->lib_version = val;
 414
 415        error = regmap_read(tsdata->regmap, HY46XX_TP_INFO, &val);
 416        if (error < 0)
 417                goto out;
 418        tsdata->tp_information = val;
 419
 420        error = regmap_read(tsdata->regmap, HY46XX_TP_CHIP_ID, &val);
 421        if (error < 0)
 422                goto out;
 423        tsdata->tp_chip_id = val;
 424
 425        error = regmap_read(tsdata->regmap, HY46XX_BOOT_VER, &val);
 426        if (error < 0)
 427                goto out;
 428        tsdata->bootloader_version = val;
 429
 430        return;
 431out:
 432        dev_err(&tsdata->client->dev, "Failed to read default settings");
 433}
 434
 435static void hycon_hy46xx_disable_regulator(void *arg)
 436{
 437        struct hycon_hy46xx_data *data = arg;
 438
 439        regulator_disable(data->vcc);
 440}
 441
 442static int hycon_hy46xx_probe(struct i2c_client *client,
 443                                         const struct i2c_device_id *id)
 444{
 445        struct hycon_hy46xx_data *tsdata;
 446        struct input_dev *input;
 447        int error;
 448
 449        dev_dbg(&client->dev, "probing for HYCON HY46XX I2C\n");
 450
 451        tsdata = devm_kzalloc(&client->dev, sizeof(*tsdata), GFP_KERNEL);
 452        if (!tsdata)
 453                return -ENOMEM;
 454
 455        tsdata->vcc = devm_regulator_get(&client->dev, "vcc");
 456        if (IS_ERR(tsdata->vcc)) {
 457                error = PTR_ERR(tsdata->vcc);
 458                if (error != -EPROBE_DEFER)
 459                        dev_err(&client->dev,
 460                                "failed to request regulator: %d\n", error);
 461                return error;
 462        }
 463
 464        error = regulator_enable(tsdata->vcc);
 465        if (error < 0) {
 466                dev_err(&client->dev, "failed to enable vcc: %d\n", error);
 467                return error;
 468        }
 469
 470        error = devm_add_action_or_reset(&client->dev,
 471                                         hycon_hy46xx_disable_regulator,
 472                                         tsdata);
 473        if (error)
 474                return error;
 475
 476        tsdata->reset_gpio = devm_gpiod_get_optional(&client->dev,
 477                                                     "reset", GPIOD_OUT_LOW);
 478        if (IS_ERR(tsdata->reset_gpio)) {
 479                error = PTR_ERR(tsdata->reset_gpio);
 480                dev_err(&client->dev,
 481                        "Failed to request GPIO reset pin, error %d\n", error);
 482                return error;
 483        }
 484
 485        if (tsdata->reset_gpio) {
 486                usleep_range(5000, 6000);
 487                gpiod_set_value_cansleep(tsdata->reset_gpio, 1);
 488                usleep_range(5000, 6000);
 489                gpiod_set_value_cansleep(tsdata->reset_gpio, 0);
 490                msleep(1000);
 491        }
 492
 493        input = devm_input_allocate_device(&client->dev);
 494        if (!input) {
 495                dev_err(&client->dev, "failed to allocate input device.\n");
 496                return -ENOMEM;
 497        }
 498
 499        mutex_init(&tsdata->mutex);
 500        tsdata->client = client;
 501        tsdata->input = input;
 502
 503        tsdata->regmap = devm_regmap_init_i2c(client,
 504                                              &hycon_hy46xx_i2c_regmap_config);
 505        if (IS_ERR(tsdata->regmap)) {
 506                dev_err(&client->dev, "regmap allocation failed\n");
 507                return PTR_ERR(tsdata->regmap);
 508        }
 509
 510        hycon_hy46xx_get_defaults(&client->dev, tsdata);
 511        hycon_hy46xx_get_parameters(tsdata);
 512
 513        input->name = "Hycon Capacitive Touch";
 514        input->id.bustype = BUS_I2C;
 515        input->dev.parent = &client->dev;
 516
 517        input_set_abs_params(input, ABS_MT_POSITION_X, 0, -1, 0, 0);
 518        input_set_abs_params(input, ABS_MT_POSITION_Y, 0, -1, 0, 0);
 519
 520        touchscreen_parse_properties(input, true, &tsdata->prop);
 521
 522        error = input_mt_init_slots(input, HY46XX_MAX_SUPPORTED_POINTS,
 523                                    INPUT_MT_DIRECT);
 524        if (error) {
 525                dev_err(&client->dev, "Unable to init MT slots.\n");
 526                return error;
 527        }
 528
 529        i2c_set_clientdata(client, tsdata);
 530
 531        error = devm_request_threaded_irq(&client->dev, client->irq,
 532                                          NULL, hycon_hy46xx_isr, IRQF_ONESHOT,
 533                                          client->name, tsdata);
 534        if (error) {
 535                dev_err(&client->dev, "Unable to request touchscreen IRQ.\n");
 536                return error;
 537        }
 538
 539        error = devm_device_add_group(&client->dev, &hycon_hy46xx_attr_group);
 540        if (error)
 541                return error;
 542
 543        error = input_register_device(input);
 544        if (error)
 545                return error;
 546
 547        dev_dbg(&client->dev,
 548                "HYCON HY46XX initialized: IRQ %d, Reset pin %d.\n",
 549                client->irq,
 550                tsdata->reset_gpio ? desc_to_gpio(tsdata->reset_gpio) : -1);
 551
 552        return 0;
 553}
 554
 555static const struct i2c_device_id hycon_hy46xx_id[] = {
 556        { .name = "hy4613" },
 557        { .name = "hy4614" },
 558        { .name = "hy4621" },
 559        { .name = "hy4623" },
 560        { .name = "hy4633" },
 561        { .name = "hy4635" },
 562        { /* sentinel */ }
 563};
 564MODULE_DEVICE_TABLE(i2c, hycon_hy46xx_id);
 565
 566static const struct of_device_id hycon_hy46xx_of_match[] = {
 567        { .compatible = "hycon,hy4613" },
 568        { .compatible = "hycon,hy4614" },
 569        { .compatible = "hycon,hy4621" },
 570        { .compatible = "hycon,hy4623" },
 571        { .compatible = "hycon,hy4633" },
 572        { .compatible = "hycon,hy4635" },
 573        { /* sentinel */ }
 574};
 575MODULE_DEVICE_TABLE(of, hycon_hy46xx_of_match);
 576
 577static struct i2c_driver hycon_hy46xx_driver = {
 578        .driver = {
 579                .name = "hycon_hy46xx",
 580                .of_match_table = hycon_hy46xx_of_match,
 581                .probe_type = PROBE_PREFER_ASYNCHRONOUS,
 582        },
 583        .id_table = hycon_hy46xx_id,
 584        .probe    = hycon_hy46xx_probe,
 585};
 586
 587module_i2c_driver(hycon_hy46xx_driver);
 588
 589MODULE_AUTHOR("Giulio Benetti <giulio.benetti@benettiengineering.com>");
 590MODULE_DESCRIPTION("HYCON HY46XX I2C Touchscreen Driver");
 591MODULE_LICENSE("GPL v2");
 592