drivers/input/touchscreen/s6sy761.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 // Samsung S6SY761 Touchscreen device driver
   3 //
   4 // Copyright (c) 2017 Samsung Electronics Co., Ltd.
   5 // Copyright (c) 2017 Andi Shyti <andi@etezian.org>
   6
   7 #include <asm/unaligned.h>
   8 #include <linux/delay.h>
   9 #include <linux/i2c.h>
  10 #include <linux/input/mt.h>
  11 #include <linux/input/touchscreen.h>
  12 #include <linux/interrupt.h>
  13 #include <linux/irq.h>
  14 #include <linux/module.h>
  15 #include <linux/pm_runtime.h>
  16 #include <linux/regulator/consumer.h>
  17
  18 /* commands */
  19 #define S6SY761_SENSE_ON                0x10
  20 #define S6SY761_SENSE_OFF               0x11
  21 #define S6SY761_TOUCH_FUNCTION          0x30 /* R/W for get/set */
  22 #define S6SY761_FIRMWARE_INTEGRITY      0x21
  23 #define S6SY761_PANEL_INFO              0x23
  24 #define S6SY761_DEVICE_ID               0x52
  25 #define S6SY761_BOOT_STATUS             0x55
  26 #define S6SY761_READ_ONE_EVENT          0x60
  27 #define S6SY761_READ_ALL_EVENT          0x61
  28 #define S6SY761_CLEAR_EVENT_STACK       0x62
  29 #define S6SY761_APPLICATION_MODE        0xe4
  30
  31 /* events */
  32 #define S6SY761_EVENT_INFO              0x02
  33 #define S6SY761_EVENT_VENDOR_INFO       0x07
  34
  35 /* info */
  36 #define S6SY761_INFO_BOOT_COMPLETE      0x00
  37
  38 /* firmware status */
  39 #define S6SY761_FW_OK                   0x80
  40
  41 /*
  42  * the functionalities are put as a reference
  43  * as in the device I am using none of them
  44  * works therefore not used in this driver yet.
  45  */
  46 /* touchscreen functionalities */
  47 #define S6SY761_MASK_TOUCH              BIT(0)
  48 #define S6SY761_MASK_HOVER              BIT(1)
  49 #define S6SY761_MASK_COVER              BIT(2)
  50 #define S6SY761_MASK_GLOVE              BIT(3)
  51 #define S6SY761_MASK_STYLUS             BIT(4)
  52 #define S6SY761_MASK_PALM               BIT(5)
  53 #define S6SY761_MASK_WET                BIT(6)
  54 #define S6SY761_MASK_PROXIMITY          BIT(7)
  55
  56 /* boot status (BS) */
  57 #define S6SY761_BS_BOOT_LOADER          0x10
  58 #define S6SY761_BS_APPLICATION          0x20
  59
  60 /* event id */
  61 #define S6SY761_EVENT_ID_COORDINATE     0x00
  62 #define S6SY761_EVENT_ID_STATUS         0x01
  63
  64 /* event register masks */
  65 #define S6SY761_MASK_TOUCH_STATE        0xc0 /* byte 0 */
  66 #define S6SY761_MASK_TID                0x3c
  67 #define S6SY761_MASK_EID                0x03
  68 #define S6SY761_MASK_X                  0xf0 /* byte 3 */
  69 #define S6SY761_MASK_Y                  0x0f
  70 #define S6SY761_MASK_Z                  0x3f /* byte 6 */
  71 #define S6SY761_MASK_LEFT_EVENTS        0x3f /* byte 7 */
  72 #define S6SY761_MASK_TOUCH_TYPE         0xc0 /* MSB in byte 6, LSB in byte 7 */
  73
  74 /* event touch state values */
  75 #define S6SY761_TS_NONE                 0x00
  76 #define S6SY761_TS_PRESS                0x01
  77 #define S6SY761_TS_MOVE                 0x02
  78 #define S6SY761_TS_RELEASE              0x03
  79
  80 /* application modes */
  81 #define S6SY761_APP_NORMAL              0x0
  82 #define S6SY761_APP_LOW_POWER           0x1
  83 #define S6SY761_APP_TEST                0x2
  84 #define S6SY761_APP_FLASH               0x3
  85 #define S6SY761_APP_SLEEP               0x4
  86
  87 #define S6SY761_EVENT_SIZE              8
  88 #define S6SY761_EVENT_COUNT             32
  89 #define S6SY761_DEVID_SIZE              3
  90 #define S6SY761_PANEL_ID_SIZE           11
  91 #define S6SY761_TS_STATUS_SIZE          5
  92 #define S6SY761_MAX_FINGERS             10
  93
  94 #define S6SY761_DEV_NAME        "s6sy761"
  95
  96 enum s6sy761_regulators {
  97         S6SY761_REGULATOR_VDD,
  98         S6SY761_REGULATOR_AVDD,
  99 };
 100
 101 struct s6sy761_data {
 102         struct i2c_client *client;
 103         struct regulator_bulk_data regulators[2];
 104         struct input_dev *input;
 105         struct touchscreen_properties prop;
 106
 107         u8 data[S6SY761_EVENT_SIZE * S6SY761_EVENT_COUNT];
 108
 109         u16 devid;
 110         u8 tx_channel;
 111 };
 112
 113 /*
 114  * We can't simply use i2c_smbus_read_i2c_block_data because we
 115  * need to read more than 255 bytes
 116  */
 117 static int s6sy761_read_events(struct s6sy761_data *sdata, u16 n_events)
 118 {
 119         u8 cmd = S6SY761_READ_ALL_EVENT;
 120         struct i2c_msg msgs[2] = {
 121                 {
 122                         .addr   = sdata->client->addr,
 123                         .len    = 1,
 124                         .buf    = &cmd,
 125                 },
 126                 {
 127                         .addr   = sdata->client->addr,
 128                         .flags  = I2C_M_RD,
 129                         .len    = (n_events * S6SY761_EVENT_SIZE),
 130                         .buf    = sdata->data + S6SY761_EVENT_SIZE,
 131                 },
 132         };
 133         int ret;
 134
 135         ret = i2c_transfer(sdata->client->adapter, msgs, ARRAY_SIZE(msgs));
 136         if (ret < 0)
 137                 return ret;
 138
 139         return ret == ARRAY_SIZE(msgs) ? 0 : -EIO;
 140 }
 141
 142 static void s6sy761_report_coordinates(struct s6sy761_data *sdata,
 143                                        u8 *event, u8 tid)
 144 {
 145         u8 major = event[4];
 146         u8 minor = event[5];
 147         u8 z = event[6] & S6SY761_MASK_Z;
 148         u16 x = (event[1] << 3) | ((event[3] & S6SY761_MASK_X) >> 4);
 149         u16 y = (event[2] << 3) | (event[3] & S6SY761_MASK_Y);
 150
 151         input_mt_slot(sdata->input, tid);
 152
 153         input_mt_report_slot_state(sdata->input, MT_TOOL_FINGER, true);
 154         input_report_abs(sdata->input, ABS_MT_POSITION_X, x);
 155         input_report_abs(sdata->input, ABS_MT_POSITION_Y, y);
 156         input_report_abs(sdata->input, ABS_MT_TOUCH_MAJOR, major);
 157         input_report_abs(sdata->input, ABS_MT_TOUCH_MINOR, minor);
 158         input_report_abs(sdata->input, ABS_MT_PRESSURE, z);
 159
 160         input_sync(sdata->input);
 161 }
 162
 163 static void s6sy761_report_release(struct s6sy761_data *sdata,
 164                                    u8 *event, u8 tid)
 165 {
 166         input_mt_slot(sdata->input, tid);
 167         input_mt_report_slot_state(sdata->input, MT_TOOL_FINGER, false);
 168
 169         input_sync(sdata->input);
 170 }
 171
 172 static void s6sy761_handle_coordinates(struct s6sy761_data *sdata, u8 *event)
 173 {
 174         u8 tid;
 175         u8 touch_state;
 176
 177         if (unlikely(!(event[0] & S6SY761_MASK_TID)))
 178                 return;
 179
 180         tid = ((event[0] & S6SY761_MASK_TID) >> 2) - 1;
 181         touch_state = (event[0] & S6SY761_MASK_TOUCH_STATE) >> 6;
 182
 183         switch (touch_state) {
 184
 185         case S6SY761_TS_NONE:
 186                 break;
 187         case S6SY761_TS_RELEASE:
 188                 s6sy761_report_release(sdata, event, tid);
 189                 break;
 190         case S6SY761_TS_PRESS:
 191         case S6SY761_TS_MOVE:
 192                 s6sy761_report_coordinates(sdata, event, tid);
 193                 break;
 194         }
 195 }
 196
 197 static void s6sy761_handle_events(struct s6sy761_data *sdata, u8 n_events)
 198 {
 199         int i;
 200
 201         for (i = 0; i < n_events; i++) {
 202                 u8 *event = &sdata->data[i * S6SY761_EVENT_SIZE];
 203                 u8 event_id = event[0] & S6SY761_MASK_EID;
 204
 205                 if (!event[0])
 206                         return;
 207
 208                 switch (event_id) {
 209
 210                 case S6SY761_EVENT_ID_COORDINATE:
 211                         s6sy761_handle_coordinates(sdata, event);
 212                         break;
 213
 214                 case S6SY761_EVENT_ID_STATUS:
 215                         break;
 216
 217                 default:
 218                         break;
 219                 }
 220         }
 221 }
 222
 223 static irqreturn_t s6sy761_irq_handler(int irq, void *dev)
 224 {
 225         struct s6sy761_data *sdata = dev;
 226         int ret;
 227         u8 n_events;
 228
 229         ret = i2c_smbus_read_i2c_block_data(sdata->client,
 230                                             S6SY761_READ_ONE_EVENT,
 231                                             S6SY761_EVENT_SIZE,
 232                                             sdata->data);
 233         if (ret < 0) {
 234                 dev_err(&sdata->client->dev, "failed to read events\n");
 235                 return IRQ_HANDLED;
 236         }
 237
 238         if (!sdata->data[0])
 239                 return IRQ_HANDLED;
 240
 241         n_events = sdata->data[7] & S6SY761_MASK_LEFT_EVENTS;
 242         if (unlikely(n_events > S6SY761_EVENT_COUNT - 1))
 243                 return IRQ_HANDLED;
 244
 245         if (n_events) {
 246                 ret = s6sy761_read_events(sdata, n_events);
 247                 if (ret < 0) {
 248                         dev_err(&sdata->client->dev, "failed to read events\n");
 249                         return IRQ_HANDLED;
 250                 }
 251         }
 252
 253         s6sy761_handle_events(sdata, n_events +  1);
 254
 255         return IRQ_HANDLED;
 256 }
 257
 258 static int s6sy761_input_open(struct input_dev *dev)
 259 {
 260         struct s6sy761_data *sdata = input_get_drvdata(dev);
 261
 262         return i2c_smbus_write_byte(sdata->client, S6SY761_SENSE_ON);
 263 }
 264
 265 static void s6sy761_input_close(struct input_dev *dev)
 266 {
 267         struct s6sy761_data *sdata = input_get_drvdata(dev);
 268         int ret;
 269
 270         ret = i2c_smbus_write_byte(sdata->client, S6SY761_SENSE_OFF);
 271         if (ret)
 272                 dev_err(&sdata->client->dev, "failed to turn off sensing\n");
 273 }
 274
 275 static ssize_t s6sy761_sysfs_devid(struct device *dev,
 276                                 struct device_attribute *attr, char *buf)
 277 {
 278         struct s6sy761_data *sdata = dev_get_drvdata(dev);
 279
 280         return sprintf(buf, "%#x\n", sdata->devid);
 281 }
 282
 283 static DEVICE_ATTR(devid, 0444, s6sy761_sysfs_devid, NULL);
 284
 285 static struct attribute *s6sy761_sysfs_attrs[] = {
 286         &dev_attr_devid.attr,
 287         NULL
 288 };
 289
 290 static struct attribute_group s6sy761_attribute_group = {
 291         .attrs = s6sy761_sysfs_attrs
 292 };
 293
 294 static int s6sy761_power_on(struct s6sy761_data *sdata)
 295 {
 296         u8 buffer[S6SY761_EVENT_SIZE];
 297         u8 event;
 298         int ret;
 299
 300         ret = regulator_bulk_enable(ARRAY_SIZE(sdata->regulators),
 301                                     sdata->regulators);
 302         if (ret)
 303                 return ret;
 304
 305         msleep(140);
 306
 307         /* double check whether the touch is functional */
 308         ret = i2c_smbus_read_i2c_block_data(sdata->client,
 309                                             S6SY761_READ_ONE_EVENT,
 310                                             S6SY761_EVENT_SIZE,
 311                                             buffer);
 312         if (ret < 0)
 313                 return ret;
 314
 315         event = (buffer[0] >> 2) & 0xf;
 316
 317         if ((event != S6SY761_EVENT_INFO &&
 318              event != S6SY761_EVENT_VENDOR_INFO) ||
 319             buffer[1] != S6SY761_INFO_BOOT_COMPLETE) {
 320                 return -ENODEV;
 321         }
 322
 323         ret = i2c_smbus_read_byte_data(sdata->client, S6SY761_BOOT_STATUS);
 324         if (ret < 0)
 325                 return ret;
 326
 327         /* for some reasons the device might be stuck in the bootloader */
 328         if (ret != S6SY761_BS_APPLICATION)
 329                 return -ENODEV;
 330
 331         /* enable touch functionality */
 332         ret = i2c_smbus_write_word_data(sdata->client,
 333                                         S6SY761_TOUCH_FUNCTION,
 334                                         S6SY761_MASK_TOUCH);
 335         if (ret)
 336                 return ret;
 337
 338         return 0;
 339 }
 340
 341 static int s6sy761_hw_init(struct s6sy761_data *sdata,
 342                            unsigned int *max_x, unsigned int *max_y)
 343 {
 344         u8 buffer[S6SY761_PANEL_ID_SIZE]; /* larger read size */
 345         int ret;
 346
 347         ret = s6sy761_power_on(sdata);
 348         if (ret)
 349                 return ret;
 350
 351         ret = i2c_smbus_read_i2c_block_data(sdata->client,
 352                                             S6SY761_DEVICE_ID,
 353                                             S6SY761_DEVID_SIZE,
 354                                             buffer);
 355         if (ret < 0)
 356                 return ret;
 357
 358         sdata->devid = get_unaligned_be16(buffer + 1);
 359
 360         ret = i2c_smbus_read_i2c_block_data(sdata->client,
 361                                             S6SY761_PANEL_INFO,
 362                                             S6SY761_PANEL_ID_SIZE,
 363                                             buffer);
 364         if (ret < 0)
 365                 return ret;
 366
 367         *max_x = get_unaligned_be16(buffer);
 368         *max_y = get_unaligned_be16(buffer + 2);
 369
 370         /* if no tx channels defined, at least keep one */
 371         sdata->tx_channel = max_t(u8, buffer[8], 1);
 372
 373         ret = i2c_smbus_read_byte_data(sdata->client,
 374                                        S6SY761_FIRMWARE_INTEGRITY);
 375         if (ret < 0)
 376                 return ret;
 377         else if (ret != S6SY761_FW_OK)
 378                 return -ENODEV;
 379
 380         return 0;
 381 }
 382
 383 static void s6sy761_power_off(void *data)
 384 {
 385         struct s6sy761_data *sdata = data;
 386
 387         disable_irq(sdata->client->irq);
 388         regulator_bulk_disable(ARRAY_SIZE(sdata->regulators),
 389                                                 sdata->regulators);
 390 }
 391
 392 static int s6sy761_probe(struct i2c_client *client,
 393                          const struct i2c_device_id *id)
 394 {
 395         struct s6sy761_data *sdata;
 396         unsigned int max_x, max_y;
 397         int err;
 398
 399         if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C |
 400                                                 I2C_FUNC_SMBUS_BYTE_DATA |
 401                                                 I2C_FUNC_SMBUS_I2C_BLOCK))
 402                 return -ENODEV;
 403
 404         sdata = devm_kzalloc(&client->dev, sizeof(*sdata), GFP_KERNEL);
 405         if (!sdata)
 406                 return -ENOMEM;
 407
 408         i2c_set_clientdata(client, sdata);
 409         sdata->client = client;
 410
 411         sdata->regulators[S6SY761_REGULATOR_VDD].supply = "vdd";
 412         sdata->regulators[S6SY761_REGULATOR_AVDD].supply = "avdd";
 413         err = devm_regulator_bulk_get(&client->dev,
 414                                       ARRAY_SIZE(sdata->regulators),
 415                                       sdata->regulators);
 416         if (err)
 417                 return err;
 418
 419         err = devm_add_action_or_reset(&client->dev, s6sy761_power_off, sdata);
 420         if (err)
 421                 return err;
 422
 423         err = s6sy761_hw_init(sdata, &max_x, &max_y);
 424         if (err)
 425                 return err;
 426
 427         sdata->input = devm_input_allocate_device(&client->dev);
 428         if (!sdata->input)
 429                 return -ENOMEM;
 430
 431         sdata->input->name = S6SY761_DEV_NAME;
 432         sdata->input->id.bustype = BUS_I2C;
 433         sdata->input->open = s6sy761_input_open;
 434         sdata->input->close = s6sy761_input_close;
 435
 436         input_set_abs_params(sdata->input, ABS_MT_POSITION_X, 0, max_x, 0, 0);
 437         input_set_abs_params(sdata->input, ABS_MT_POSITION_Y, 0, max_y, 0, 0);
 438         input_set_abs_params(sdata->input, ABS_MT_TOUCH_MAJOR, 0, 255, 0, 0);
 439         input_set_abs_params(sdata->input, ABS_MT_TOUCH_MINOR, 0, 255, 0, 0);
 440         input_set_abs_params(sdata->input, ABS_MT_TOUCH_MAJOR, 0, 255, 0, 0);
 441         input_set_abs_params(sdata->input, ABS_MT_TOUCH_MINOR, 0, 255, 0, 0);
 442         input_set_abs_params(sdata->input, ABS_MT_PRESSURE, 0, 255, 0, 0);
 443
 444         touchscreen_parse_properties(sdata->input, true, &sdata->prop);
 445
 446         if (!input_abs_get_max(sdata->input, ABS_X) ||
 447             !input_abs_get_max(sdata->input, ABS_Y)) {
 448                 dev_warn(&client->dev, "the axis have not been set\n");
 449         }
 450
 451         err = input_mt_init_slots(sdata->input, sdata->tx_channel,
 452                                   INPUT_MT_DIRECT);
 453         if (err)
 454                 return err;
 455
 456         input_set_drvdata(sdata->input, sdata);
 457
 458         err = input_register_device(sdata->input);
 459         if (err)
 460                 return err;
 461
 462         err = devm_request_threaded_irq(&client->dev, client->irq, NULL,
 463                                         s6sy761_irq_handler,
 464                                         IRQF_TRIGGER_LOW | IRQF_ONESHOT,
 465                                         "s6sy761_irq", sdata);
 466         if (err)
 467                 return err;
 468
 469         err = devm_device_add_group(&client->dev, &s6sy761_attribute_group);
 470         if (err)
 471                 return err;
 472
 473         pm_runtime_enable(&client->dev);
 474
 475         return 0;
 476 }
 477
 478 static int s6sy761_remove(struct i2c_client *client)
 479 {
 480         pm_runtime_disable(&client->dev);
 481
 482         return 0;
 483 }
 484
 485 static int __maybe_unused s6sy761_runtime_suspend(struct device *dev)
 486 {
 487         struct s6sy761_data *sdata = dev_get_drvdata(dev);
 488
 489         return i2c_smbus_write_byte_data(sdata->client,
 490                                 S6SY761_APPLICATION_MODE, S6SY761_APP_SLEEP);
 491 }
 492
 493 static int __maybe_unused s6sy761_runtime_resume(struct device *dev)
 494 {
 495         struct s6sy761_data *sdata = dev_get_drvdata(dev);
 496
 497         return i2c_smbus_write_byte_data(sdata->client,
 498                                 S6SY761_APPLICATION_MODE, S6SY761_APP_NORMAL);
 499 }
 500
 501 static int __maybe_unused s6sy761_suspend(struct device *dev)
 502 {
 503         struct s6sy761_data *sdata = dev_get_drvdata(dev);
 504
 505         s6sy761_power_off(sdata);
 506
 507         return 0;
 508 }
 509
 510 static int __maybe_unused s6sy761_resume(struct device *dev)
 511 {
 512         struct s6sy761_data *sdata = dev_get_drvdata(dev);
 513
 514         enable_irq(sdata->client->irq);
 515
 516         return s6sy761_power_on(sdata);
 517 }
 518
 519 static const struct dev_pm_ops s6sy761_pm_ops = {
 520         SET_SYSTEM_SLEEP_PM_OPS(s6sy761_suspend, s6sy761_resume)
 521         SET_RUNTIME_PM_OPS(s6sy761_runtime_suspend,
 522                                 s6sy761_runtime_resume, NULL)
 523 };
 524
 525 #ifdef CONFIG_OF
 526 static const struct of_device_id s6sy761_of_match[] = {
 527         { .compatible = "samsung,s6sy761", },
 528         { },
 529 };
 530 MODULE_DEVICE_TABLE(of, s6sy761_of_match);
 531 #endif
 532
 533 static const struct i2c_device_id s6sy761_id[] = {
 534         { "s6sy761", 0 },
 535         { },
 536 };
 537 MODULE_DEVICE_TABLE(i2c, s6sy761_id);
 538
 539 static struct i2c_driver s6sy761_driver = {
 540         .driver = {
 541                 .name = S6SY761_DEV_NAME,
 542                 .of_match_table = of_match_ptr(s6sy761_of_match),
 543                 .pm = &s6sy761_pm_ops,
 544         },
 545         .probe = s6sy761_probe,
 546         .remove = s6sy761_remove,
 547         .id_table = s6sy761_id,
 548 };
 549
 550 module_i2c_driver(s6sy761_driver);
 551
 552 MODULE_AUTHOR("Andi Shyti <andi.shyti@samsung.com>");
 553 MODULE_DESCRIPTION("Samsung S6SY761 Touch Screen");
 554 MODULE_LICENSE("GPL v2");