drivers/input/touchscreen/ili210x.c

   1 #include <linux/module.h>
   2 #include <linux/i2c.h>
   3 #include <linux/interrupt.h>
   4 #include <linux/slab.h>
   5 #include <linux/input.h>
   6 #include <linux/input/mt.h>
   7 #include <linux/input/touchscreen.h>
   8 #include <linux/delay.h>
   9 #include <linux/workqueue.h>
  10 #include <linux/gpio/consumer.h>
  11 #include <linux/of_device.h>
  12 #include <asm/unaligned.h>
  13
  14 #define ILI210X_TOUCHES         2
  15 #define ILI251X_TOUCHES         10
  16 #define DEFAULT_POLL_PERIOD     20
  17
  18 /* Touchscreen commands */
  19 #define REG_TOUCHDATA           0x10
  20 #define REG_PANEL_INFO          0x20
  21 #define REG_FIRMWARE_VERSION    0x40
  22 #define REG_CALIBRATE           0xcc
  23
  24 struct firmware_version {
  25         u8 id;
  26         u8 major;
  27         u8 minor;
  28 } __packed;
  29
  30 enum ili2xxx_model {
  31         MODEL_ILI210X,
  32         MODEL_ILI251X,
  33 };
  34
  35 struct ili210x {
  36         struct i2c_client *client;
  37         struct input_dev *input;
  38         unsigned int poll_period;
  39         struct delayed_work dwork;
  40         struct gpio_desc *reset_gpio;
  41         struct touchscreen_properties prop;
  42         enum ili2xxx_model model;
  43         unsigned int max_touches;
  44 };
  45
  46 static int ili210x_read_reg(struct i2c_client *client, u8 reg, void *buf,
  47                             size_t len)
  48 {
  49         struct ili210x *priv = i2c_get_clientdata(client);
  50         struct i2c_msg msg[2] = {
  51                 {
  52                         .addr   = client->addr,
  53                         .flags  = 0,
  54                         .len    = 1,
  55                         .buf    = &reg,
  56                 },
  57                 {
  58                         .addr   = client->addr,
  59                         .flags  = I2C_M_RD,
  60                         .len    = len,
  61                         .buf    = buf,
  62                 }
  63         };
  64
  65         if (priv->model == MODEL_ILI251X) {
  66                 if (i2c_transfer(client->adapter, msg, 1) != 1) {
  67                         dev_err(&client->dev, "i2c transfer failed\n");
  68                         return -EIO;
  69                 }
  70
  71                 usleep_range(5000, 5500);
  72
  73                 if (i2c_transfer(client->adapter, msg + 1, 1) != 1) {
  74                         dev_err(&client->dev, "i2c transfer failed\n");
  75                         return -EIO;
  76                 }
  77         } else {
  78                 if (i2c_transfer(client->adapter, msg, 2) != 2) {
  79                         dev_err(&client->dev, "i2c transfer failed\n");
  80                         return -EIO;
  81                 }
  82         }
  83
  84         return 0;
  85 }
  86
  87 static int ili210x_read(struct i2c_client *client, void *buf, size_t len)
  88 {
  89         struct i2c_msg msg = {
  90                 .addr   = client->addr,
  91                 .flags  = I2C_M_RD,
  92                 .len    = len,
  93                 .buf    = buf,
  94         };
  95
  96         if (i2c_transfer(client->adapter, &msg, 1) != 1) {
  97                 dev_err(&client->dev, "i2c transfer failed\n");
  98                 return -EIO;
  99         }
 100
 101         return 0;
 102 }
 103
 104 static bool ili210x_touchdata_to_coords(struct ili210x *priv, u8 *touchdata,
 105                                         unsigned int finger,
 106                                         unsigned int *x, unsigned int *y)
 107 {
 108         if (finger >= ILI210X_TOUCHES)
 109                 return false;
 110
 111         if (touchdata[0] & BIT(finger))
 112                 return false;
 113
 114         *x = get_unaligned_be16(touchdata + 1 + (finger * 4) + 0);
 115         *y = get_unaligned_be16(touchdata + 1 + (finger * 4) + 2);
 116
 117         return true;
 118 }
 119
 120 static bool ili251x_touchdata_to_coords(struct ili210x *priv, u8 *touchdata,
 121                                         unsigned int finger,
 122                                         unsigned int *x, unsigned int *y)
 123 {
 124         if (finger >= ILI251X_TOUCHES)
 125                 return false;
 126
 127         *x = get_unaligned_be16(touchdata + 1 + (finger * 5) + 0);
 128         if (!(*x & BIT(15)))    /* Touch indication */
 129                 return false;
 130
 131         *x &= 0x3fff;
 132         *y = get_unaligned_be16(touchdata + 1 + (finger * 5) + 2);
 133
 134         return true;
 135 }
 136
 137 static bool ili210x_report_events(struct ili210x *priv, u8 *touchdata)
 138 {
 139         struct input_dev *input = priv->input;
 140         int i;
 141         bool contact = false, touch = false;
 142         unsigned int x = 0, y = 0;
 143
 144         for (i = 0; i < priv->max_touches; i++) {
 145                 if (priv->model == MODEL_ILI210X) {
 146                         touch = ili210x_touchdata_to_coords(priv, touchdata,
 147                                                             i, &x, &y);
 148                 } else if (priv->model == MODEL_ILI251X) {
 149                         touch = ili251x_touchdata_to_coords(priv, touchdata,
 150                                                             i, &x, &y);
 151                         if (touch)
 152                                 contact = true;
 153                 }
 154
 155                 input_mt_slot(input, i);
 156                 input_mt_report_slot_state(input, MT_TOOL_FINGER, touch);
 157                 if (!touch)
 158                         continue;
 159                 touchscreen_report_pos(input, &priv->prop, x, y,
 160                                        true);
 161         }
 162
 163         input_mt_report_pointer_emulation(input, false);
 164         input_sync(input);
 165
 166         if (priv->model == MODEL_ILI210X)
 167                 contact = touchdata[0] & 0xf3;
 168
 169         return contact;
 170 }
 171
 172 static void ili210x_work(struct work_struct *work)
 173 {
 174         struct ili210x *priv = container_of(work, struct ili210x,
 175                                             dwork.work);
 176         struct i2c_client *client = priv->client;
 177         u8 touchdata[64] = { 0 };
 178         bool touch;
 179         int error = -EINVAL;
 180
 181         if (priv->model == MODEL_ILI210X) {
 182                 error = ili210x_read_reg(client, REG_TOUCHDATA,
 183                                          touchdata, sizeof(touchdata));
 184         } else if (priv->model == MODEL_ILI251X) {
 185                 error = ili210x_read_reg(client, REG_TOUCHDATA,
 186                                          touchdata, 31);
 187                 if (!error && touchdata[0] == 2)
 188                         error = ili210x_read(client, &touchdata[31], 20);
 189         }
 190
 191         if (error) {
 192                 dev_err(&client->dev,
 193                         "Unable to get touchdata, err = %d\n", error);
 194                 return;
 195         }
 196
 197         touch = ili210x_report_events(priv, touchdata);
 198
 199         if (touch)
 200                 schedule_delayed_work(&priv->dwork,
 201                                       msecs_to_jiffies(priv->poll_period));
 202 }
 203
 204 static irqreturn_t ili210x_irq(int irq, void *irq_data)
 205 {
 206         struct ili210x *priv = irq_data;
 207
 208         schedule_delayed_work(&priv->dwork, 0);
 209
 210         return IRQ_HANDLED;
 211 }
 212
 213 static ssize_t ili210x_calibrate(struct device *dev,
 214                                  struct device_attribute *attr,
 215                                  const char *buf, size_t count)
 216 {
 217         struct i2c_client *client = to_i2c_client(dev);
 218         struct ili210x *priv = i2c_get_clientdata(client);
 219         unsigned long calibrate;
 220         int rc;
 221         u8 cmd = REG_CALIBRATE;
 222
 223         if (kstrtoul(buf, 10, &calibrate))
 224                 return -EINVAL;
 225
 226         if (calibrate > 1)
 227                 return -EINVAL;
 228
 229         if (calibrate) {
 230                 rc = i2c_master_send(priv->client, &cmd, sizeof(cmd));
 231                 if (rc != sizeof(cmd))
 232                         return -EIO;
 233         }
 234
 235         return count;
 236 }
 237 static DEVICE_ATTR(calibrate, S_IWUSR, NULL, ili210x_calibrate);
 238
 239 static struct attribute *ili210x_attributes[] = {
 240         &dev_attr_calibrate.attr,
 241         NULL,
 242 };
 243
 244 static const struct attribute_group ili210x_attr_group = {
 245         .attrs = ili210x_attributes,
 246 };
 247
 248 static void ili210x_power_down(void *data)
 249 {
 250         struct gpio_desc *reset_gpio = data;
 251
 252         gpiod_set_value_cansleep(reset_gpio, 1);
 253 }
 254
 255 static void ili210x_cancel_work(void *data)
 256 {
 257         struct ili210x *priv = data;
 258
 259         cancel_delayed_work_sync(&priv->dwork);
 260 }
 261
 262 static int ili210x_i2c_probe(struct i2c_client *client,
 263                                        const struct i2c_device_id *id)
 264 {
 265         struct device *dev = &client->dev;
 266         struct ili210x *priv;
 267         struct gpio_desc *reset_gpio;
 268         struct input_dev *input;
 269         struct firmware_version firmware;
 270         enum ili2xxx_model model;
 271         int error;
 272
 273         model = (enum ili2xxx_model)id->driver_data;
 274
 275         dev_dbg(dev, "Probing for ILI210X I2C Touschreen driver");
 276
 277         if (client->irq <= 0) {
 278                 dev_err(dev, "No IRQ!\n");
 279                 return -EINVAL;
 280         }
 281
 282         reset_gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH);
 283         if (IS_ERR(reset_gpio))
 284                 return PTR_ERR(reset_gpio);
 285
 286         if (reset_gpio) {
 287                 error = devm_add_action_or_reset(dev, ili210x_power_down,
 288                                                  reset_gpio);
 289                 if (error)
 290                         return error;
 291
 292                 usleep_range(50, 100);
 293                 gpiod_set_value_cansleep(reset_gpio, 0);
 294                 msleep(100);
 295         }
 296
 297         priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
 298         if (!priv)
 299                 return -ENOMEM;
 300
 301         input = devm_input_allocate_device(dev);
 302         if (!input)
 303                 return -ENOMEM;
 304
 305         priv->client = client;
 306         priv->input = input;
 307         priv->poll_period = DEFAULT_POLL_PERIOD;
 308         INIT_DELAYED_WORK(&priv->dwork, ili210x_work);
 309         priv->reset_gpio = reset_gpio;
 310         priv->model = model;
 311         if (model == MODEL_ILI210X)
 312                 priv->max_touches = ILI210X_TOUCHES;
 313         if (model == MODEL_ILI251X)
 314                 priv->max_touches = ILI251X_TOUCHES;
 315
 316         i2c_set_clientdata(client, priv);
 317
 318         /* Get firmware version */
 319         error = ili210x_read_reg(client, REG_FIRMWARE_VERSION,
 320                                  &firmware, sizeof(firmware));
 321         if (error) {
 322                 dev_err(dev, "Failed to get firmware version, err: %d\n",
 323                         error);
 324                 return error;
 325         }
 326
 327         /* Setup input device */
 328         input->name = "ILI210x Touchscreen";
 329         input->id.bustype = BUS_I2C;
 330         input->dev.parent = dev;
 331
 332         /* Multi touch */
 333         input_set_abs_params(input, ABS_MT_POSITION_X, 0, 0xffff, 0, 0);
 334         input_set_abs_params(input, ABS_MT_POSITION_Y, 0, 0xffff, 0, 0);
 335         touchscreen_parse_properties(input, true, &priv->prop);
 336         input_mt_init_slots(input, priv->max_touches, INPUT_MT_DIRECT);
 337
 338         error = devm_add_action(dev, ili210x_cancel_work, priv);
 339         if (error)
 340                 return error;
 341
 342         error = devm_request_irq(dev, client->irq, ili210x_irq, 0,
 343                                  client->name, priv);
 344         if (error) {
 345                 dev_err(dev, "Unable to request touchscreen IRQ, err: %d\n",
 346                         error);
 347                 return error;
 348         }
 349
 350         error = devm_device_add_group(dev, &ili210x_attr_group);
 351         if (error) {
 352                 dev_err(dev, "Unable to create sysfs attributes, err: %d\n",
 353                         error);
 354                 return error;
 355         }
 356
 357         error = input_register_device(priv->input);
 358         if (error) {
 359                 dev_err(dev, "Cannot register input device, err: %d\n", error);
 360                 return error;
 361         }
 362
 363         device_init_wakeup(dev, 1);
 364
 365         dev_dbg(dev,
 366                 "ILI210x initialized (IRQ: %d), firmware version %d.%d.%d",
 367                 client->irq, firmware.id, firmware.major, firmware.minor);
 368
 369         return 0;
 370 }
 371
 372 static int __maybe_unused ili210x_i2c_suspend(struct device *dev)
 373 {
 374         struct i2c_client *client = to_i2c_client(dev);
 375
 376         if (device_may_wakeup(&client->dev))
 377                 enable_irq_wake(client->irq);
 378
 379         return 0;
 380 }
 381
 382 static int __maybe_unused ili210x_i2c_resume(struct device *dev)
 383 {
 384         struct i2c_client *client = to_i2c_client(dev);
 385
 386         if (device_may_wakeup(&client->dev))
 387                 disable_irq_wake(client->irq);
 388
 389         return 0;
 390 }
 391
 392 static SIMPLE_DEV_PM_OPS(ili210x_i2c_pm,
 393                          ili210x_i2c_suspend, ili210x_i2c_resume);
 394
 395 static const struct i2c_device_id ili210x_i2c_id[] = {
 396         { "ili210x", MODEL_ILI210X },
 397         { "ili251x", MODEL_ILI251X },
 398         { }
 399 };
 400 MODULE_DEVICE_TABLE(i2c, ili210x_i2c_id);
 401
 402 static const struct of_device_id ili210x_dt_ids[] = {
 403         { .compatible = "ilitek,ili210x", .data = (void *)MODEL_ILI210X },
 404         { .compatible = "ilitek,ili251x", .data = (void *)MODEL_ILI251X },
 405         { },
 406 };
 407 MODULE_DEVICE_TABLE(of, ili210x_dt_ids);
 408
 409 static struct i2c_driver ili210x_ts_driver = {
 410         .driver = {
 411                 .name = "ili210x_i2c",
 412                 .pm = &ili210x_i2c_pm,
 413                 .of_match_table = ili210x_dt_ids,
 414         },
 415         .id_table = ili210x_i2c_id,
 416         .probe = ili210x_i2c_probe,
 417 };
 418
 419 module_i2c_driver(ili210x_ts_driver);
 420
 421 MODULE_AUTHOR("Olivier Sobrie <olivier@sobrie.be>");
 422 MODULE_DESCRIPTION("ILI210X I2C Touchscreen Driver");
 423 MODULE_LICENSE("GPL");