drivers/input/touchscreen/ili210x.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 #include <linux/delay.h>
   3 #include <linux/gpio/consumer.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/module.h>
  10 #include <linux/of_device.h>
  11 #include <linux/sizes.h>
  12 #include <linux/slab.h>
  13 #include <asm/unaligned.h>
  14
  15 #define ILI2XXX_POLL_PERIOD     20
  16
  17 #define ILI210X_DATA_SIZE       64
  18 #define ILI211X_DATA_SIZE       43
  19 #define ILI251X_DATA_SIZE1      31
  20 #define ILI251X_DATA_SIZE2      20
  21
  22 /* Touchscreen commands */
  23 #define REG_TOUCHDATA           0x10
  24 #define REG_PANEL_INFO          0x20
  25 #define REG_CALIBRATE           0xcc
  26
  27 struct ili2xxx_chip {
  28         int (*read_reg)(struct i2c_client *client, u8 reg,
  29                         void *buf, size_t len);
  30         int (*get_touch_data)(struct i2c_client *client, u8 *data);
  31         bool (*parse_touch_data)(const u8 *data, unsigned int finger,
  32                                  unsigned int *x, unsigned int *y);
  33         bool (*continue_polling)(const u8 *data, bool touch);
  34         unsigned int max_touches;
  35         unsigned int resolution;
  36         bool has_calibrate_reg;
  37 };
  38
  39 struct ili210x {
  40         struct i2c_client *client;
  41         struct input_dev *input;
  42         struct gpio_desc *reset_gpio;
  43         struct touchscreen_properties prop;
  44         const struct ili2xxx_chip *chip;
  45         bool stop;
  46 };
  47
  48 static int ili210x_read_reg(struct i2c_client *client,
  49                             u8 reg, void *buf, size_t len)
  50 {
  51         struct i2c_msg msg[] = {
  52                 {
  53                         .addr   = client->addr,
  54                         .flags  = 0,
  55                         .len    = 1,
  56                         .buf    = &reg,
  57                 },
  58                 {
  59                         .addr   = client->addr,
  60                         .flags  = I2C_M_RD,
  61                         .len    = len,
  62                         .buf    = buf,
  63                 }
  64         };
  65         int error, ret;
  66
  67         ret = i2c_transfer(client->adapter, msg, ARRAY_SIZE(msg));
  68         if (ret != ARRAY_SIZE(msg)) {
  69                 error = ret < 0 ? ret : -EIO;
  70                 dev_err(&client->dev, "%s failed: %d\n", __func__, error);
  71                 return error;
  72         }
  73
  74         return 0;
  75 }
  76
  77 static int ili210x_read_touch_data(struct i2c_client *client, u8 *data)
  78 {
  79         return ili210x_read_reg(client, REG_TOUCHDATA,
  80                                 data, ILI210X_DATA_SIZE);
  81 }
  82
  83 static bool ili210x_touchdata_to_coords(const u8 *touchdata,
  84                                         unsigned int finger,
  85                                         unsigned int *x, unsigned int *y)
  86 {
  87         if (touchdata[0] & BIT(finger))
  88                 return false;
  89
  90         *x = get_unaligned_be16(touchdata + 1 + (finger * 4) + 0);
  91         *y = get_unaligned_be16(touchdata + 1 + (finger * 4) + 2);
  92
  93         return true;
  94 }
  95
  96 static bool ili210x_check_continue_polling(const u8 *data, bool touch)
  97 {
  98         return data[0] & 0xf3;
  99 }
 100
 101 static const struct ili2xxx_chip ili210x_chip = {
 102         .read_reg               = ili210x_read_reg,
 103         .get_touch_data         = ili210x_read_touch_data,
 104         .parse_touch_data       = ili210x_touchdata_to_coords,
 105         .continue_polling       = ili210x_check_continue_polling,
 106         .max_touches            = 2,
 107         .has_calibrate_reg      = true,
 108 };
 109
 110 static int ili211x_read_touch_data(struct i2c_client *client, u8 *data)
 111 {
 112         s16 sum = 0;
 113         int error;
 114         int ret;
 115         int i;
 116
 117         ret = i2c_master_recv(client, data, ILI211X_DATA_SIZE);
 118         if (ret != ILI211X_DATA_SIZE) {
 119                 error = ret < 0 ? ret : -EIO;
 120                 dev_err(&client->dev, "%s failed: %d\n", __func__, error);
 121                 return error;
 122         }
 123
 124         /* This chip uses custom checksum at the end of data */
 125         for (i = 0; i < ILI211X_DATA_SIZE - 1; i++)
 126                 sum = (sum + data[i]) & 0xff;
 127
 128         if ((-sum & 0xff) != data[ILI211X_DATA_SIZE - 1]) {
 129                 dev_err(&client->dev,
 130                         "CRC error (crc=0x%02x expected=0x%02x)\n",
 131                         sum, data[ILI211X_DATA_SIZE - 1]);
 132                 return -EIO;
 133         }
 134
 135         return 0;
 136 }
 137
 138 static bool ili211x_touchdata_to_coords(const u8 *touchdata,
 139                                         unsigned int finger,
 140                                         unsigned int *x, unsigned int *y)
 141 {
 142         u32 data;
 143
 144         data = get_unaligned_be32(touchdata + 1 + (finger * 4) + 0);
 145         if (data == 0xffffffff) /* Finger up */
 146                 return false;
 147
 148         *x = ((touchdata[1 + (finger * 4) + 0] & 0xf0) << 4) |
 149              touchdata[1 + (finger * 4) + 1];
 150         *y = ((touchdata[1 + (finger * 4) + 0] & 0x0f) << 8) |
 151              touchdata[1 + (finger * 4) + 2];
 152
 153         return true;
 154 }
 155
 156 static bool ili211x_decline_polling(const u8 *data, bool touch)
 157 {
 158         return false;
 159 }
 160
 161 static const struct ili2xxx_chip ili211x_chip = {
 162         .read_reg               = ili210x_read_reg,
 163         .get_touch_data         = ili211x_read_touch_data,
 164         .parse_touch_data       = ili211x_touchdata_to_coords,
 165         .continue_polling       = ili211x_decline_polling,
 166         .max_touches            = 10,
 167         .resolution             = 2048,
 168 };
 169
 170 static int ili251x_read_reg(struct i2c_client *client,
 171                             u8 reg, void *buf, size_t len)
 172 {
 173         int error;
 174         int ret;
 175
 176         ret = i2c_master_send(client, &reg, 1);
 177         if (ret == 1) {
 178                 usleep_range(5000, 5500);
 179
 180                 ret = i2c_master_recv(client, buf, len);
 181                 if (ret == len)
 182                         return 0;
 183         }
 184
 185         error = ret < 0 ? ret : -EIO;
 186         dev_err(&client->dev, "%s failed: %d\n", __func__, error);
 187         return ret;
 188 }
 189
 190 static int ili251x_read_touch_data(struct i2c_client *client, u8 *data)
 191 {
 192         int error;
 193
 194         error = ili251x_read_reg(client, REG_TOUCHDATA,
 195                                  data, ILI251X_DATA_SIZE1);
 196         if (!error && data[0] == 2) {
 197                 error = i2c_master_recv(client, data + ILI251X_DATA_SIZE1,
 198                                         ILI251X_DATA_SIZE2);
 199                 if (error >= 0 && error != ILI251X_DATA_SIZE2)
 200                         error = -EIO;
 201         }
 202
 203         return error;
 204 }
 205
 206 static bool ili251x_touchdata_to_coords(const u8 *touchdata,
 207                                         unsigned int finger,
 208                                         unsigned int *x, unsigned int *y)
 209 {
 210         u16 val;
 211
 212         val = get_unaligned_be16(touchdata + 1 + (finger * 5) + 0);
 213         if (!(val & BIT(15)))   /* Touch indication */
 214                 return false;
 215
 216         *x = val & 0x3fff;
 217         *y = get_unaligned_be16(touchdata + 1 + (finger * 5) + 2);
 218
 219         return true;
 220 }
 221
 222 static bool ili251x_check_continue_polling(const u8 *data, bool touch)
 223 {
 224         return touch;
 225 }
 226
 227 static const struct ili2xxx_chip ili251x_chip = {
 228         .read_reg               = ili251x_read_reg,
 229         .get_touch_data         = ili251x_read_touch_data,
 230         .parse_touch_data       = ili251x_touchdata_to_coords,
 231         .continue_polling       = ili251x_check_continue_polling,
 232         .max_touches            = 10,
 233         .has_calibrate_reg      = true,
 234 };
 235
 236 static bool ili210x_report_events(struct ili210x *priv, u8 *touchdata)
 237 {
 238         struct input_dev *input = priv->input;
 239         int i;
 240         bool contact = false, touch;
 241         unsigned int x = 0, y = 0;
 242
 243         for (i = 0; i < priv->chip->max_touches; i++) {
 244                 touch = priv->chip->parse_touch_data(touchdata, i, &x, &y);
 245
 246                 input_mt_slot(input, i);
 247                 if (input_mt_report_slot_state(input, MT_TOOL_FINGER, touch)) {
 248                         touchscreen_report_pos(input, &priv->prop, x, y, true);
 249                         contact = true;
 250                 }
 251         }
 252
 253         input_mt_report_pointer_emulation(input, false);
 254         input_sync(input);
 255
 256         return contact;
 257 }
 258
 259 static irqreturn_t ili210x_irq(int irq, void *irq_data)
 260 {
 261         struct ili210x *priv = irq_data;
 262         struct i2c_client *client = priv->client;
 263         const struct ili2xxx_chip *chip = priv->chip;
 264         u8 touchdata[ILI210X_DATA_SIZE] = { 0 };
 265         bool keep_polling;
 266         bool touch;
 267         int error;
 268
 269         do {
 270                 error = chip->get_touch_data(client, touchdata);
 271                 if (error) {
 272                         dev_err(&client->dev,
 273                                 "Unable to get touch data: %d\n", error);
 274                         break;
 275                 }
 276
 277                 touch = ili210x_report_events(priv, touchdata);
 278                 keep_polling = chip->continue_polling(touchdata, touch);
 279                 if (keep_polling)
 280                         msleep(ILI2XXX_POLL_PERIOD);
 281         } while (!priv->stop && keep_polling);
 282
 283         return IRQ_HANDLED;
 284 }
 285
 286 static ssize_t ili210x_calibrate(struct device *dev,
 287                                  struct device_attribute *attr,
 288                                  const char *buf, size_t count)
 289 {
 290         struct i2c_client *client = to_i2c_client(dev);
 291         struct ili210x *priv = i2c_get_clientdata(client);
 292         unsigned long calibrate;
 293         int rc;
 294         u8 cmd = REG_CALIBRATE;
 295
 296         if (kstrtoul(buf, 10, &calibrate))
 297                 return -EINVAL;
 298
 299         if (calibrate > 1)
 300                 return -EINVAL;
 301
 302         if (calibrate) {
 303                 rc = i2c_master_send(priv->client, &cmd, sizeof(cmd));
 304                 if (rc != sizeof(cmd))
 305                         return -EIO;
 306         }
 307
 308         return count;
 309 }
 310 static DEVICE_ATTR(calibrate, S_IWUSR, NULL, ili210x_calibrate);
 311
 312 static struct attribute *ili210x_attributes[] = {
 313         &dev_attr_calibrate.attr,
 314         NULL,
 315 };
 316
 317 static umode_t ili210x_calibrate_visible(struct kobject *kobj,
 318                                           struct attribute *attr, int index)
 319 {
 320         struct device *dev = kobj_to_dev(kobj);
 321         struct i2c_client *client = to_i2c_client(dev);
 322         struct ili210x *priv = i2c_get_clientdata(client);
 323
 324         return priv->chip->has_calibrate_reg;
 325 }
 326
 327 static const struct attribute_group ili210x_attr_group = {
 328         .attrs = ili210x_attributes,
 329         .is_visible = ili210x_calibrate_visible,
 330 };
 331
 332 static void ili210x_power_down(void *data)
 333 {
 334         struct gpio_desc *reset_gpio = data;
 335
 336         gpiod_set_value_cansleep(reset_gpio, 1);
 337 }
 338
 339 static void ili210x_stop(void *data)
 340 {
 341         struct ili210x *priv = data;
 342
 343         /* Tell ISR to quit even if there is a contact. */
 344         priv->stop = true;
 345 }
 346
 347 static int ili210x_i2c_probe(struct i2c_client *client,
 348                              const struct i2c_device_id *id)
 349 {
 350         struct device *dev = &client->dev;
 351         const struct ili2xxx_chip *chip;
 352         struct ili210x *priv;
 353         struct gpio_desc *reset_gpio;
 354         struct input_dev *input;
 355         int error;
 356         unsigned int max_xy;
 357
 358         dev_dbg(dev, "Probing for ILI210X I2C Touschreen driver");
 359
 360         chip = device_get_match_data(dev);
 361         if (!chip && id)
 362                 chip = (const struct ili2xxx_chip *)id->driver_data;
 363         if (!chip) {
 364                 dev_err(&client->dev, "unknown device model\n");
 365                 return -ENODEV;
 366         }
 367
 368         if (client->irq <= 0) {
 369                 dev_err(dev, "No IRQ!\n");
 370                 return -EINVAL;
 371         }
 372
 373         reset_gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH);
 374         if (IS_ERR(reset_gpio))
 375                 return PTR_ERR(reset_gpio);
 376
 377         if (reset_gpio) {
 378                 error = devm_add_action_or_reset(dev, ili210x_power_down,
 379                                                  reset_gpio);
 380                 if (error)
 381                         return error;
 382
 383                 usleep_range(50, 100);
 384                 gpiod_set_value_cansleep(reset_gpio, 0);
 385                 msleep(100);
 386         }
 387
 388         priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
 389         if (!priv)
 390                 return -ENOMEM;
 391
 392         input = devm_input_allocate_device(dev);
 393         if (!input)
 394                 return -ENOMEM;
 395
 396         priv->client = client;
 397         priv->input = input;
 398         priv->reset_gpio = reset_gpio;
 399         priv->chip = chip;
 400         i2c_set_clientdata(client, priv);
 401
 402         /* Setup input device */
 403         input->name = "ILI210x Touchscreen";
 404         input->id.bustype = BUS_I2C;
 405
 406         /* Multi touch */
 407         max_xy = (chip->resolution ?: SZ_64K) - 1;
 408         input_set_abs_params(input, ABS_MT_POSITION_X, 0, max_xy, 0, 0);
 409         input_set_abs_params(input, ABS_MT_POSITION_Y, 0, max_xy, 0, 0);
 410         touchscreen_parse_properties(input, true, &priv->prop);
 411
 412         error = input_mt_init_slots(input, priv->chip->max_touches,
 413                                     INPUT_MT_DIRECT);
 414         if (error) {
 415                 dev_err(dev, "Unable to set up slots, err: %d\n", error);
 416                 return error;
 417         }
 418
 419         error = devm_request_threaded_irq(dev, client->irq, NULL, ili210x_irq,
 420                                           IRQF_ONESHOT, client->name, priv);
 421         if (error) {
 422                 dev_err(dev, "Unable to request touchscreen IRQ, err: %d\n",
 423                         error);
 424                 return error;
 425         }
 426
 427         error = devm_add_action_or_reset(dev, ili210x_stop, priv);
 428         if (error)
 429                 return error;
 430
 431         error = devm_device_add_group(dev, &ili210x_attr_group);
 432         if (error) {
 433                 dev_err(dev, "Unable to create sysfs attributes, err: %d\n",
 434                         error);
 435                 return error;
 436         }
 437
 438         error = input_register_device(priv->input);
 439         if (error) {
 440                 dev_err(dev, "Cannot register input device, err: %d\n", error);
 441                 return error;
 442         }
 443
 444         return 0;
 445 }
 446
 447 static const struct i2c_device_id ili210x_i2c_id[] = {
 448         { "ili210x", (long)&ili210x_chip },
 449         { "ili2117", (long)&ili211x_chip },
 450         { "ili251x", (long)&ili251x_chip },
 451         { }
 452 };
 453 MODULE_DEVICE_TABLE(i2c, ili210x_i2c_id);
 454
 455 static const struct of_device_id ili210x_dt_ids[] = {
 456         { .compatible = "ilitek,ili210x", .data = &ili210x_chip },
 457         { .compatible = "ilitek,ili2117", .data = &ili211x_chip },
 458         { .compatible = "ilitek,ili251x", .data = &ili251x_chip },
 459         { }
 460 };
 461 MODULE_DEVICE_TABLE(of, ili210x_dt_ids);
 462
 463 static struct i2c_driver ili210x_ts_driver = {
 464         .driver = {
 465                 .name = "ili210x_i2c",
 466                 .of_match_table = ili210x_dt_ids,
 467         },
 468         .id_table = ili210x_i2c_id,
 469         .probe = ili210x_i2c_probe,
 470 };
 471
 472 module_i2c_driver(ili210x_ts_driver);
 473
 474 MODULE_AUTHOR("Olivier Sobrie <olivier@sobrie.be>");
 475 MODULE_DESCRIPTION("ILI210X I2C Touchscreen Driver");
 476 MODULE_LICENSE("GPL");