drivers/input/touchscreen/exc3000.c

   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");