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/delay.h>
   8 #include <linux/workqueue.h>
   9 #include <linux/input/ili210x.h>
  10
  11 #define MAX_TOUCHES             2
  12 #define DEFAULT_POLL_PERIOD     20
  13
  14 /* Touchscreen commands */
  15 #define REG_TOUCHDATA           0x10
  16 #define REG_PANEL_INFO          0x20
  17 #define REG_FIRMWARE_VERSION    0x40
  18 #define REG_CALIBRATE           0xcc
  19
  20 struct finger {
  21         u8 x_low;
  22         u8 x_high;
  23         u8 y_low;
  24         u8 y_high;
  25 } __packed;
  26
  27 struct touchdata {
  28         u8 status;
  29         struct finger finger[MAX_TOUCHES];
  30 } __packed;
  31
  32 struct panel_info {
  33         struct finger finger_max;
  34         u8 xchannel_num;
  35         u8 ychannel_num;
  36 } __packed;
  37
  38 struct firmware_version {
  39         u8 id;
  40         u8 major;
  41         u8 minor;
  42 } __packed;
  43
  44 struct ili210x {
  45         struct i2c_client *client;
  46         struct input_dev *input;
  47         bool (*get_pendown_state)(void);
  48         unsigned int poll_period;
  49         struct delayed_work dwork;
  50 };
  51
  52 static int ili210x_read_reg(struct i2c_client *client, u8 reg, void *buf,
  53                             size_t len)
  54 {
  55         struct i2c_msg msg[2] = {
  56                 {
  57                         .addr   = client->addr,
  58                         .flags  = 0,
  59                         .len    = 1,
  60                         .buf    = &reg,
  61                 },
  62                 {
  63                         .addr   = client->addr,
  64                         .flags  = I2C_M_RD,
  65                         .len    = len,
  66                         .buf    = buf,
  67                 }
  68         };
  69
  70         if (i2c_transfer(client->adapter, msg, 2) != 2) {
  71                 dev_err(&client->dev, "i2c transfer failed\n");
  72                 return -EIO;
  73         }
  74
  75         return 0;
  76 }
  77
  78 static void ili210x_report_events(struct input_dev *input,
  79                                   const struct touchdata *touchdata)
  80 {
  81         int i;
  82         bool touch;
  83         unsigned int x, y;
  84         const struct finger *finger;
  85
  86         for (i = 0; i < MAX_TOUCHES; i++) {
  87                 input_mt_slot(input, i);
  88
  89                 finger = &touchdata->finger[i];
  90
  91                 touch = touchdata->status & (1 << i);
  92                 input_mt_report_slot_state(input, MT_TOOL_FINGER, touch);
  93                 if (touch) {
  94                         x = finger->x_low | (finger->x_high << 8);
  95                         y = finger->y_low | (finger->y_high << 8);
  96
  97                         input_report_abs(input, ABS_MT_POSITION_X, x);
  98                         input_report_abs(input, ABS_MT_POSITION_Y, y);
  99                 }
 100         }
 101
 102         input_mt_report_pointer_emulation(input, false);
 103         input_sync(input);
 104 }
 105
 106 static bool get_pendown_state(const struct ili210x *priv)
 107 {
 108         bool state = false;
 109
 110         if (priv->get_pendown_state)
 111                 state = priv->get_pendown_state();
 112
 113         return state;
 114 }
 115
 116 static void ili210x_work(struct work_struct *work)
 117 {
 118         struct ili210x *priv = container_of(work, struct ili210x,
 119                                             dwork.work);
 120         struct i2c_client *client = priv->client;
 121         struct touchdata touchdata;
 122         int error;
 123
 124         error = ili210x_read_reg(client, REG_TOUCHDATA,
 125                                  &touchdata, sizeof(touchdata));
 126         if (error) {
 127                 dev_err(&client->dev,
 128                         "Unable to get touchdata, err = %d\n", error);
 129                 return;
 130         }
 131
 132         ili210x_report_events(priv->input, &touchdata);
 133
 134         if ((touchdata.status & 0xf3) || get_pendown_state(priv))
 135                 schedule_delayed_work(&priv->dwork,
 136                                       msecs_to_jiffies(priv->poll_period));
 137 }
 138
 139 static irqreturn_t ili210x_irq(int irq, void *irq_data)
 140 {
 141         struct ili210x *priv = irq_data;
 142
 143         schedule_delayed_work(&priv->dwork, 0);
 144
 145         return IRQ_HANDLED;
 146 }
 147
 148 static ssize_t ili210x_calibrate(struct device *dev,
 149                                  struct device_attribute *attr,
 150                                  const char *buf, size_t count)
 151 {
 152         struct i2c_client *client = to_i2c_client(dev);
 153         struct ili210x *priv = i2c_get_clientdata(client);
 154         unsigned long calibrate;
 155         int rc;
 156         u8 cmd = REG_CALIBRATE;
 157
 158         if (kstrtoul(buf, 10, &calibrate))
 159                 return -EINVAL;
 160
 161         if (calibrate > 1)
 162                 return -EINVAL;
 163
 164         if (calibrate) {
 165                 rc = i2c_master_send(priv->client, &cmd, sizeof(cmd));
 166                 if (rc != sizeof(cmd))
 167                         return -EIO;
 168         }
 169
 170         return count;
 171 }
 172 static DEVICE_ATTR(calibrate, S_IWUSR, NULL, ili210x_calibrate);
 173
 174 static struct attribute *ili210x_attributes[] = {
 175         &dev_attr_calibrate.attr,
 176         NULL,
 177 };
 178
 179 static const struct attribute_group ili210x_attr_group = {
 180         .attrs = ili210x_attributes,
 181 };
 182
 183 static int ili210x_i2c_probe(struct i2c_client *client,
 184                                        const struct i2c_device_id *id)
 185 {
 186         struct device *dev = &client->dev;
 187         const struct ili210x_platform_data *pdata = dev_get_platdata(dev);
 188         struct ili210x *priv;
 189         struct input_dev *input;
 190         struct panel_info panel;
 191         struct firmware_version firmware;
 192         int xmax, ymax;
 193         int error;
 194
 195         dev_dbg(dev, "Probing for ILI210X I2C Touschreen driver");
 196
 197         if (!pdata) {
 198                 dev_err(dev, "No platform data!\n");
 199                 return -EINVAL;
 200         }
 201
 202         if (client->irq <= 0) {
 203                 dev_err(dev, "No IRQ!\n");
 204                 return -EINVAL;
 205         }
 206
 207         /* Get firmware version */
 208         error = ili210x_read_reg(client, REG_FIRMWARE_VERSION,
 209                                  &firmware, sizeof(firmware));
 210         if (error) {
 211                 dev_err(dev, "Failed to get firmware version, err: %d\n",
 212                         error);
 213                 return error;
 214         }
 215
 216         /* get panel info */
 217         error = ili210x_read_reg(client, REG_PANEL_INFO, &panel, sizeof(panel));
 218         if (error) {
 219                 dev_err(dev, "Failed to get panel information, err: %d\n",
 220                         error);
 221                 return error;
 222         }
 223
 224         xmax = panel.finger_max.x_low | (panel.finger_max.x_high << 8);
 225         ymax = panel.finger_max.y_low | (panel.finger_max.y_high << 8);
 226
 227         priv = kzalloc(sizeof(*priv), GFP_KERNEL);
 228         input = input_allocate_device();
 229         if (!priv || !input) {
 230                 error = -ENOMEM;
 231                 goto err_free_mem;
 232         }
 233
 234         priv->client = client;
 235         priv->input = input;
 236         priv->get_pendown_state = pdata->get_pendown_state;
 237         priv->poll_period = pdata->poll_period ? : DEFAULT_POLL_PERIOD;
 238         INIT_DELAYED_WORK(&priv->dwork, ili210x_work);
 239
 240         /* Setup input device */
 241         input->name = "ILI210x Touchscreen";
 242         input->id.bustype = BUS_I2C;
 243         input->dev.parent = dev;
 244
 245         __set_bit(EV_SYN, input->evbit);
 246         __set_bit(EV_KEY, input->evbit);
 247         __set_bit(EV_ABS, input->evbit);
 248         __set_bit(BTN_TOUCH, input->keybit);
 249
 250         /* Single touch */
 251         input_set_abs_params(input, ABS_X, 0, xmax, 0, 0);
 252         input_set_abs_params(input, ABS_Y, 0, ymax, 0, 0);
 253
 254         /* Multi touch */
 255         input_mt_init_slots(input, MAX_TOUCHES, 0);
 256         input_set_abs_params(input, ABS_MT_POSITION_X, 0, xmax, 0, 0);
 257         input_set_abs_params(input, ABS_MT_POSITION_Y, 0, ymax, 0, 0);
 258
 259         input_set_drvdata(input, priv);
 260         i2c_set_clientdata(client, priv);
 261
 262         error = request_irq(client->irq, ili210x_irq, pdata->irq_flags,
 263                             client->name, priv);
 264         if (error) {
 265                 dev_err(dev, "Unable to request touchscreen IRQ, err: %d\n",
 266                         error);
 267                 goto err_free_mem;
 268         }
 269
 270         error = sysfs_create_group(&dev->kobj, &ili210x_attr_group);
 271         if (error) {
 272                 dev_err(dev, "Unable to create sysfs attributes, err: %d\n",
 273                         error);
 274                 goto err_free_irq;
 275         }
 276
 277         error = input_register_device(priv->input);
 278         if (error) {
 279                 dev_err(dev, "Cannot register input device, err: %d\n", error);
 280                 goto err_remove_sysfs;
 281         }
 282
 283         device_init_wakeup(&client->dev, 1);
 284
 285         dev_dbg(dev,
 286                 "ILI210x initialized (IRQ: %d), firmware version %d.%d.%d",
 287                 client->irq, firmware.id, firmware.major, firmware.minor);
 288
 289         return 0;
 290
 291 err_remove_sysfs:
 292         sysfs_remove_group(&dev->kobj, &ili210x_attr_group);
 293 err_free_irq:
 294         free_irq(client->irq, priv);
 295 err_free_mem:
 296         input_free_device(input);
 297         kfree(priv);
 298         return error;
 299 }
 300
 301 static int ili210x_i2c_remove(struct i2c_client *client)
 302 {
 303         struct ili210x *priv = i2c_get_clientdata(client);
 304
 305         sysfs_remove_group(&client->dev.kobj, &ili210x_attr_group);
 306         free_irq(priv->client->irq, priv);
 307         cancel_delayed_work_sync(&priv->dwork);
 308         input_unregister_device(priv->input);
 309         kfree(priv);
 310
 311         return 0;
 312 }
 313
 314 static int __maybe_unused ili210x_i2c_suspend(struct device *dev)
 315 {
 316         struct i2c_client *client = to_i2c_client(dev);
 317
 318         if (device_may_wakeup(&client->dev))
 319                 enable_irq_wake(client->irq);
 320
 321         return 0;
 322 }
 323
 324 static int __maybe_unused ili210x_i2c_resume(struct device *dev)
 325 {
 326         struct i2c_client *client = to_i2c_client(dev);
 327
 328         if (device_may_wakeup(&client->dev))
 329                 disable_irq_wake(client->irq);
 330
 331         return 0;
 332 }
 333
 334 static SIMPLE_DEV_PM_OPS(ili210x_i2c_pm,
 335                          ili210x_i2c_suspend, ili210x_i2c_resume);
 336
 337 static const struct i2c_device_id ili210x_i2c_id[] = {
 338         { "ili210x", 0 },
 339         { }
 340 };
 341 MODULE_DEVICE_TABLE(i2c, ili210x_i2c_id);
 342
 343 static struct i2c_driver ili210x_ts_driver = {
 344         .driver = {
 345                 .name = "ili210x_i2c",
 346                 .pm = &ili210x_i2c_pm,
 347         },
 348         .id_table = ili210x_i2c_id,
 349         .probe = ili210x_i2c_probe,
 350         .remove = ili210x_i2c_remove,
 351 };
 352
 353 module_i2c_driver(ili210x_ts_driver);
 354
 355 MODULE_AUTHOR("Olivier Sobrie <olivier@sobrie.be>");
 356 MODULE_DESCRIPTION("ILI210X I2C Touchscreen Driver");
 357 MODULE_LICENSE("GPL");