drivers/input/touchscreen/pixcir_i2c_ts.c

   1 /*
   2  * Driver for Pixcir I2C touchscreen controllers.
   3  *
   4  * Copyright (C) 2010-2011 Pixcir, Inc.
   5  *
   6  * This software is licensed under the terms of the GNU General Public
   7  * License version 2, as published by the Free Software Foundation, and
   8  * may be copied, distributed, and modified under those terms.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public
  16  * License along with this library; if not, write to the Free Software
  17  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
  18  */
  19
  20 #include <linux/delay.h>
  21 #include <linux/module.h>
  22 #include <linux/interrupt.h>
  23 #include <linux/slab.h>
  24 #include <linux/i2c.h>
  25 #include <linux/input.h>
  26 #include <linux/input/pixcir_ts.h>
  27 #include <linux/gpio.h>
  28
  29 struct pixcir_i2c_ts_data {
  30         struct i2c_client *client;
  31         struct input_dev *input;
  32         const struct pixcir_ts_platform_data *chip;
  33         bool running;
  34 };
  35
  36 static void pixcir_ts_poscheck(struct pixcir_i2c_ts_data *data)
  37 {
  38         struct pixcir_i2c_ts_data *tsdata = data;
  39         u8 rdbuf[10], wrbuf[1] = { 0 };
  40         u8 touch;
  41         int ret;
  42
  43         ret = i2c_master_send(tsdata->client, wrbuf, sizeof(wrbuf));
  44         if (ret != sizeof(wrbuf)) {
  45                 dev_err(&tsdata->client->dev,
  46                         "%s: i2c_master_send failed(), ret=%d\n",
  47                         __func__, ret);
  48                 return;
  49         }
  50
  51         ret = i2c_master_recv(tsdata->client, rdbuf, sizeof(rdbuf));
  52         if (ret != sizeof(rdbuf)) {
  53                 dev_err(&tsdata->client->dev,
  54                         "%s: i2c_master_recv failed(), ret=%d\n",
  55                         __func__, ret);
  56                 return;
  57         }
  58
  59         touch = rdbuf[0];
  60         if (touch) {
  61                 u16 posx1 = (rdbuf[3] << 8) | rdbuf[2];
  62                 u16 posy1 = (rdbuf[5] << 8) | rdbuf[4];
  63                 u16 posx2 = (rdbuf[7] << 8) | rdbuf[6];
  64                 u16 posy2 = (rdbuf[9] << 8) | rdbuf[8];
  65
  66                 input_report_key(tsdata->input, BTN_TOUCH, 1);
  67                 input_report_abs(tsdata->input, ABS_X, posx1);
  68                 input_report_abs(tsdata->input, ABS_Y, posy1);
  69
  70                 input_report_abs(tsdata->input, ABS_MT_POSITION_X, posx1);
  71                 input_report_abs(tsdata->input, ABS_MT_POSITION_Y, posy1);
  72                 input_mt_sync(tsdata->input);
  73
  74                 if (touch == 2) {
  75                         input_report_abs(tsdata->input,
  76                                          ABS_MT_POSITION_X, posx2);
  77                         input_report_abs(tsdata->input,
  78                                          ABS_MT_POSITION_Y, posy2);
  79                         input_mt_sync(tsdata->input);
  80                 }
  81         } else {
  82                 input_report_key(tsdata->input, BTN_TOUCH, 0);
  83         }
  84
  85         input_sync(tsdata->input);
  86 }
  87
  88 static irqreturn_t pixcir_ts_isr(int irq, void *dev_id)
  89 {
  90         struct pixcir_i2c_ts_data *tsdata = dev_id;
  91         const struct pixcir_ts_platform_data *pdata = tsdata->chip;
  92
  93         while (tsdata->running) {
  94                 pixcir_ts_poscheck(tsdata);
  95
  96                 if (gpio_get_value(pdata->gpio_attb))
  97                         break;
  98
  99                 msleep(20);
 100         }
 101
 102         return IRQ_HANDLED;
 103 }
 104
 105 static int pixcir_set_power_mode(struct pixcir_i2c_ts_data *ts,
 106                                  enum pixcir_power_mode mode)
 107 {
 108         struct device *dev = &ts->client->dev;
 109         int ret;
 110
 111         ret = i2c_smbus_read_byte_data(ts->client, PIXCIR_REG_POWER_MODE);
 112         if (ret < 0) {
 113                 dev_err(dev, "%s: can't read reg 0x%x : %d\n",
 114                         __func__, PIXCIR_REG_POWER_MODE, ret);
 115                 return ret;
 116         }
 117
 118         ret &= ~PIXCIR_POWER_MODE_MASK;
 119         ret |= mode;
 120
 121         /* Always AUTO_IDLE */
 122         ret |= PIXCIR_POWER_ALLOW_IDLE;
 123
 124         ret = i2c_smbus_write_byte_data(ts->client, PIXCIR_REG_POWER_MODE, ret);
 125         if (ret < 0) {
 126                 dev_err(dev, "%s: can't write reg 0x%x : %d\n",
 127                         __func__, PIXCIR_REG_POWER_MODE, ret);
 128                 return ret;
 129         }
 130
 131         return 0;
 132 }
 133
 134 /*
 135  * Set the interrupt mode for the device i.e. ATTB line behaviour
 136  *
 137  * @polarity : 1 for active high, 0 for active low.
 138  */
 139 static int pixcir_set_int_mode(struct pixcir_i2c_ts_data *ts,
 140                                enum pixcir_int_mode mode, bool polarity)
 141 {
 142         struct device *dev = &ts->client->dev;
 143         int ret;
 144
 145         ret = i2c_smbus_read_byte_data(ts->client, PIXCIR_REG_INT_MODE);
 146         if (ret < 0) {
 147                 dev_err(dev, "%s: can't read reg 0x%x : %d\n",
 148                         __func__, PIXCIR_REG_INT_MODE, ret);
 149                 return ret;
 150         }
 151
 152         ret &= ~PIXCIR_INT_MODE_MASK;
 153         ret |= mode;
 154
 155         if (polarity)
 156                 ret |= PIXCIR_INT_POL_HIGH;
 157         else
 158                 ret &= ~PIXCIR_INT_POL_HIGH;
 159
 160         ret = i2c_smbus_write_byte_data(ts->client, PIXCIR_REG_INT_MODE, ret);
 161         if (ret < 0) {
 162                 dev_err(dev, "%s: can't write reg 0x%x : %d\n",
 163                         __func__, PIXCIR_REG_INT_MODE, ret);
 164                 return ret;
 165         }
 166
 167         return 0;
 168 }
 169
 170 /*
 171  * Enable/disable interrupt generation
 172  */
 173 static int pixcir_int_enable(struct pixcir_i2c_ts_data *ts, bool enable)
 174 {
 175         struct device *dev = &ts->client->dev;
 176         int ret;
 177
 178         ret = i2c_smbus_read_byte_data(ts->client, PIXCIR_REG_INT_MODE);
 179         if (ret < 0) {
 180                 dev_err(dev, "%s: can't read reg 0x%x : %d\n",
 181                         __func__, PIXCIR_REG_INT_MODE, ret);
 182                 return ret;
 183         }
 184
 185         if (enable)
 186                 ret |= PIXCIR_INT_ENABLE;
 187         else
 188                 ret &= ~PIXCIR_INT_ENABLE;
 189
 190         ret = i2c_smbus_write_byte_data(ts->client, PIXCIR_REG_INT_MODE, ret);
 191         if (ret < 0) {
 192                 dev_err(dev, "%s: can't write reg 0x%x : %d\n",
 193                         __func__, PIXCIR_REG_INT_MODE, ret);
 194                 return ret;
 195         }
 196
 197         return 0;
 198 }
 199
 200 static int pixcir_start(struct pixcir_i2c_ts_data *ts)
 201 {
 202         struct device *dev = &ts->client->dev;
 203         int error;
 204
 205         /* LEVEL_TOUCH interrupt with active low polarity */
 206         error = pixcir_set_int_mode(ts, PIXCIR_INT_LEVEL_TOUCH, 0);
 207         if (error) {
 208                 dev_err(dev, "Failed to set interrupt mode: %d\n", error);
 209                 return error;
 210         }
 211
 212         ts->running = true;
 213         mb();   /* Update status before IRQ can fire */
 214
 215         /* enable interrupt generation */
 216         error = pixcir_int_enable(ts, true);
 217         if (error) {
 218                 dev_err(dev, "Failed to enable interrupt generation: %d\n",
 219                         error);
 220                 return error;
 221         }
 222
 223         return 0;
 224 }
 225
 226 static int pixcir_stop(struct pixcir_i2c_ts_data *ts)
 227 {
 228         int error;
 229
 230         /* Disable interrupt generation */
 231         error = pixcir_int_enable(ts, false);
 232         if (error) {
 233                 dev_err(&ts->client->dev,
 234                         "Failed to disable interrupt generation: %d\n",
 235                         error);
 236                 return error;
 237         }
 238
 239         /* Exit ISR if running, no more report parsing */
 240         ts->running = false;
 241         mb();   /* update status before we synchronize irq */
 242
 243         /* Wait till running ISR is complete */
 244         synchronize_irq(ts->client->irq);
 245
 246         return 0;
 247 }
 248
 249 static int pixcir_input_open(struct input_dev *dev)
 250 {
 251         struct pixcir_i2c_ts_data *ts = input_get_drvdata(dev);
 252
 253         return pixcir_start(ts);
 254 }
 255
 256 static void pixcir_input_close(struct input_dev *dev)
 257 {
 258         struct pixcir_i2c_ts_data *ts = input_get_drvdata(dev);
 259
 260         pixcir_stop(ts);
 261 }
 262
 263 #ifdef CONFIG_PM_SLEEP
 264 static int pixcir_i2c_ts_suspend(struct device *dev)
 265 {
 266         struct i2c_client *client = to_i2c_client(dev);
 267         struct pixcir_i2c_ts_data *ts = i2c_get_clientdata(client);
 268         struct input_dev *input = ts->input;
 269         int ret = 0;
 270
 271         mutex_lock(&input->mutex);
 272
 273         if (device_may_wakeup(&client->dev)) {
 274                 if (!input->users) {
 275                         ret = pixcir_start(ts);
 276                         if (ret) {
 277                                 dev_err(dev, "Failed to start\n");
 278                                 goto unlock;
 279                         }
 280                 }
 281
 282                 enable_irq_wake(client->irq);
 283         } else if (input->users) {
 284                 ret = pixcir_stop(ts);
 285         }
 286
 287 unlock:
 288         mutex_unlock(&input->mutex);
 289
 290         return ret;
 291 }
 292
 293 static int pixcir_i2c_ts_resume(struct device *dev)
 294 {
 295         struct i2c_client *client = to_i2c_client(dev);
 296         struct pixcir_i2c_ts_data *ts = i2c_get_clientdata(client);
 297         struct input_dev *input = ts->input;
 298         int ret = 0;
 299
 300         mutex_lock(&input->mutex);
 301
 302         if (device_may_wakeup(&client->dev)) {
 303                 disable_irq_wake(client->irq);
 304
 305                 if (!input->users) {
 306                         ret = pixcir_stop(ts);
 307                         if (ret) {
 308                                 dev_err(dev, "Failed to stop\n");
 309                                 goto unlock;
 310                         }
 311                 }
 312         } else if (input->users) {
 313                 ret = pixcir_start(ts);
 314         }
 315
 316 unlock:
 317         mutex_unlock(&input->mutex);
 318
 319         return ret;
 320 }
 321 #endif
 322
 323 static SIMPLE_DEV_PM_OPS(pixcir_dev_pm_ops,
 324                          pixcir_i2c_ts_suspend, pixcir_i2c_ts_resume);
 325
 326 static int pixcir_i2c_ts_probe(struct i2c_client *client,
 327                                          const struct i2c_device_id *id)
 328 {
 329         const struct pixcir_ts_platform_data *pdata =
 330                         dev_get_platdata(&client->dev);
 331         struct device *dev = &client->dev;
 332         struct pixcir_i2c_ts_data *tsdata;
 333         struct input_dev *input;
 334         int error;
 335
 336         if (!pdata) {
 337                 dev_err(&client->dev, "platform data not defined\n");
 338                 return -EINVAL;
 339         }
 340
 341         if (!gpio_is_valid(pdata->gpio_attb)) {
 342                 dev_err(dev, "Invalid gpio_attb in pdata\n");
 343                 return -EINVAL;
 344         }
 345
 346         tsdata = devm_kzalloc(dev, sizeof(*tsdata), GFP_KERNEL);
 347         if (!tsdata)
 348                 return -ENOMEM;
 349
 350         input = devm_input_allocate_device(dev);
 351         if (!input) {
 352                 dev_err(dev, "Failed to allocate input device\n");
 353                 return -ENOMEM;
 354         }
 355
 356         tsdata->client = client;
 357         tsdata->input = input;
 358         tsdata->chip = pdata;
 359
 360         input->name = client->name;
 361         input->id.bustype = BUS_I2C;
 362         input->open = pixcir_input_open;
 363         input->close = pixcir_input_close;
 364         input->dev.parent = &client->dev;
 365
 366         __set_bit(EV_KEY, input->evbit);
 367         __set_bit(EV_ABS, input->evbit);
 368         __set_bit(BTN_TOUCH, input->keybit);
 369         input_set_abs_params(input, ABS_X, 0, pdata->x_max, 0, 0);
 370         input_set_abs_params(input, ABS_Y, 0, pdata->y_max, 0, 0);
 371         input_set_abs_params(input, ABS_MT_POSITION_X, 0, pdata->x_max, 0, 0);
 372         input_set_abs_params(input, ABS_MT_POSITION_Y, 0, pdata->y_max, 0, 0);
 373
 374         input_set_drvdata(input, tsdata);
 375
 376         error = devm_gpio_request_one(dev, pdata->gpio_attb,
 377                                       GPIOF_DIR_IN, "pixcir_i2c_attb");
 378         if (error) {
 379                 dev_err(dev, "Failed to request ATTB gpio\n");
 380                 return error;
 381         }
 382
 383         error = devm_request_threaded_irq(dev, client->irq, NULL, pixcir_ts_isr,
 384                                           IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
 385                                           client->name, tsdata);
 386         if (error) {
 387                 dev_err(dev, "failed to request irq %d\n", client->irq);
 388                 return error;
 389         }
 390
 391         /* Always be in IDLE mode to save power, device supports auto wake */
 392         error = pixcir_set_power_mode(tsdata, PIXCIR_POWER_IDLE);
 393         if (error) {
 394                 dev_err(dev, "Failed to set IDLE mode\n");
 395                 return error;
 396         }
 397
 398         /* Stop device till opened */
 399         error = pixcir_stop(tsdata);
 400         if (error)
 401                 return error;
 402
 403         error = input_register_device(input);
 404         if (error)
 405                 return error;
 406
 407         i2c_set_clientdata(client, tsdata);
 408         device_init_wakeup(&client->dev, 1);
 409
 410         return 0;
 411 }
 412
 413 static int pixcir_i2c_ts_remove(struct i2c_client *client)
 414 {
 415         device_init_wakeup(&client->dev, 0);
 416
 417         return 0;
 418 }
 419
 420 static const struct i2c_device_id pixcir_i2c_ts_id[] = {
 421         { "pixcir_ts", 0 },
 422         { }
 423 };
 424 MODULE_DEVICE_TABLE(i2c, pixcir_i2c_ts_id);
 425
 426 static struct i2c_driver pixcir_i2c_ts_driver = {
 427         .driver = {
 428                 .owner  = THIS_MODULE,
 429                 .name   = "pixcir_ts",
 430                 .pm     = &pixcir_dev_pm_ops,
 431         },
 432         .probe          = pixcir_i2c_ts_probe,
 433         .remove         = pixcir_i2c_ts_remove,
 434         .id_table       = pixcir_i2c_ts_id,
 435 };
 436
 437 module_i2c_driver(pixcir_i2c_ts_driver);
 438
 439 MODULE_AUTHOR("Jianchun Bian <jcbian@pixcir.com.cn>, Dequan Meng <dqmeng@pixcir.com.cn>");
 440 MODULE_DESCRIPTION("Pixcir I2C Touchscreen Driver");
 441 MODULE_LICENSE("GPL");