drivers/input/touchscreen/ucb1400_ts.c

   1 /*
   2  *  Philips UCB1400 touchscreen driver
   3  *
   4  *  Author:     Nicolas Pitre
   5  *  Created:    September 25, 2006
   6  *  Copyright:  MontaVista Software, Inc.
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License version 2 as
  10  * published by the Free Software Foundation.
  11  *
  12  * This code is heavily based on ucb1x00-*.c copyrighted by Russell King
  13  * covering the UCB1100, UCB1200 and UCB1300..  Support for the UCB1400 has
  14  * been made separate from ucb1x00-core/ucb1x00-ts on Russell's request.
  15  */
  16
  17 #include <linux/module.h>
  18 #include <linux/moduleparam.h>
  19 #include <linux/init.h>
  20 #include <linux/completion.h>
  21 #include <linux/delay.h>
  22 #include <linux/input.h>
  23 #include <linux/device.h>
  24 #include <linux/interrupt.h>
  25 #include <linux/suspend.h>
  26 #include <linux/slab.h>
  27 #include <linux/kthread.h>
  28 #include <linux/freezer.h>
  29
  30 #include <sound/driver.h>
  31 #include <sound/core.h>
  32 #include <sound/ac97_codec.h>
  33
  34
  35 /*
  36  * Interesting UCB1400 AC-link registers
  37  */
  38
  39 #define UCB_IE_RIS              0x5e
  40 #define UCB_IE_FAL              0x60
  41 #define UCB_IE_STATUS           0x62
  42 #define UCB_IE_CLEAR            0x62
  43 #define UCB_IE_ADC              (1 << 11)
  44 #define UCB_IE_TSPX             (1 << 12)
  45
  46 #define UCB_TS_CR               0x64
  47 #define UCB_TS_CR_TSMX_POW      (1 << 0)
  48 #define UCB_TS_CR_TSPX_POW      (1 << 1)
  49 #define UCB_TS_CR_TSMY_POW      (1 << 2)
  50 #define UCB_TS_CR_TSPY_POW      (1 << 3)
  51 #define UCB_TS_CR_TSMX_GND      (1 << 4)
  52 #define UCB_TS_CR_TSPX_GND      (1 << 5)
  53 #define UCB_TS_CR_TSMY_GND      (1 << 6)
  54 #define UCB_TS_CR_TSPY_GND      (1 << 7)
  55 #define UCB_TS_CR_MODE_INT      (0 << 8)
  56 #define UCB_TS_CR_MODE_PRES     (1 << 8)
  57 #define UCB_TS_CR_MODE_POS      (2 << 8)
  58 #define UCB_TS_CR_BIAS_ENA      (1 << 11)
  59 #define UCB_TS_CR_TSPX_LOW      (1 << 12)
  60 #define UCB_TS_CR_TSMX_LOW      (1 << 13)
  61
  62 #define UCB_ADC_CR              0x66
  63 #define UCB_ADC_SYNC_ENA        (1 << 0)
  64 #define UCB_ADC_VREFBYP_CON     (1 << 1)
  65 #define UCB_ADC_INP_TSPX        (0 << 2)
  66 #define UCB_ADC_INP_TSMX        (1 << 2)
  67 #define UCB_ADC_INP_TSPY        (2 << 2)
  68 #define UCB_ADC_INP_TSMY        (3 << 2)
  69 #define UCB_ADC_INP_AD0         (4 << 2)
  70 #define UCB_ADC_INP_AD1         (5 << 2)
  71 #define UCB_ADC_INP_AD2         (6 << 2)
  72 #define UCB_ADC_INP_AD3         (7 << 2)
  73 #define UCB_ADC_EXT_REF         (1 << 5)
  74 #define UCB_ADC_START           (1 << 7)
  75 #define UCB_ADC_ENA             (1 << 15)
  76
  77 #define UCB_ADC_DATA            0x68
  78 #define UCB_ADC_DAT_VALID       (1 << 15)
  79 #define UCB_ADC_DAT_VALUE(x)    ((x) & 0x3ff)
  80
  81 #define UCB_ID                  0x7e
  82 #define UCB_ID_1400             0x4304
  83
  84
  85 struct ucb1400 {
  86         struct snd_ac97         *ac97;
  87         struct input_dev        *ts_idev;
  88
  89         int                     irq;
  90
  91         wait_queue_head_t       ts_wait;
  92         struct task_struct      *ts_task;
  93
  94         unsigned int            irq_pending;    /* not bit field shared */
  95         unsigned int            ts_restart:1;
  96         unsigned int            adcsync:1;
  97 };
  98
  99 static int adcsync;
 100
 101 static inline u16 ucb1400_reg_read(struct ucb1400 *ucb, u16 reg)
 102 {
 103         return ucb->ac97->bus->ops->read(ucb->ac97, reg);
 104 }
 105
 106 static inline void ucb1400_reg_write(struct ucb1400 *ucb, u16 reg, u16 val)
 107 {
 108         ucb->ac97->bus->ops->write(ucb->ac97, reg, val);
 109 }
 110
 111 static inline void ucb1400_adc_enable(struct ucb1400 *ucb)
 112 {
 113         ucb1400_reg_write(ucb, UCB_ADC_CR, UCB_ADC_ENA);
 114 }
 115
 116 static unsigned int ucb1400_adc_read(struct ucb1400 *ucb, u16 adc_channel)
 117 {
 118         unsigned int val;
 119
 120         if (ucb->adcsync)
 121                 adc_channel |= UCB_ADC_SYNC_ENA;
 122
 123         ucb1400_reg_write(ucb, UCB_ADC_CR, UCB_ADC_ENA | adc_channel);
 124         ucb1400_reg_write(ucb, UCB_ADC_CR, UCB_ADC_ENA | adc_channel | UCB_ADC_START);
 125
 126         for (;;) {
 127                 val = ucb1400_reg_read(ucb, UCB_ADC_DATA);
 128                 if (val & UCB_ADC_DAT_VALID)
 129                         break;
 130                 /* yield to other processes */
 131                 set_current_state(TASK_INTERRUPTIBLE);
 132                 schedule_timeout(1);
 133         }
 134
 135         return UCB_ADC_DAT_VALUE(val);
 136 }
 137
 138 static inline void ucb1400_adc_disable(struct ucb1400 *ucb)
 139 {
 140         ucb1400_reg_write(ucb, UCB_ADC_CR, 0);
 141 }
 142
 143 /* Switch to interrupt mode. */
 144 static inline void ucb1400_ts_mode_int(struct ucb1400 *ucb)
 145 {
 146         ucb1400_reg_write(ucb, UCB_TS_CR,
 147                         UCB_TS_CR_TSMX_POW | UCB_TS_CR_TSPX_POW |
 148                         UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_GND |
 149                         UCB_TS_CR_MODE_INT);
 150 }
 151
 152 /*
 153  * Switch to pressure mode, and read pressure.  We don't need to wait
 154  * here, since both plates are being driven.
 155  */
 156 static inline unsigned int ucb1400_ts_read_pressure(struct ucb1400 *ucb)
 157 {
 158         ucb1400_reg_write(ucb, UCB_TS_CR,
 159                         UCB_TS_CR_TSMX_POW | UCB_TS_CR_TSPX_POW |
 160                         UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_GND |
 161                         UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA);
 162         return ucb1400_adc_read(ucb, UCB_ADC_INP_TSPY);
 163 }
 164
 165 /*
 166  * Switch to X position mode and measure Y plate.  We switch the plate
 167  * configuration in pressure mode, then switch to position mode.  This
 168  * gives a faster response time.  Even so, we need to wait about 55us
 169  * for things to stabilise.
 170  */
 171 static inline unsigned int ucb1400_ts_read_xpos(struct ucb1400 *ucb)
 172 {
 173         ucb1400_reg_write(ucb, UCB_TS_CR,
 174                         UCB_TS_CR_TSMX_GND | UCB_TS_CR_TSPX_POW |
 175                         UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA);
 176         ucb1400_reg_write(ucb, UCB_TS_CR,
 177                         UCB_TS_CR_TSMX_GND | UCB_TS_CR_TSPX_POW |
 178                         UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA);
 179         ucb1400_reg_write(ucb, UCB_TS_CR,
 180                         UCB_TS_CR_TSMX_GND | UCB_TS_CR_TSPX_POW |
 181                         UCB_TS_CR_MODE_POS | UCB_TS_CR_BIAS_ENA);
 182
 183         udelay(55);
 184
 185         return ucb1400_adc_read(ucb, UCB_ADC_INP_TSPY);
 186 }
 187
 188 /*
 189  * Switch to Y position mode and measure X plate.  We switch the plate
 190  * configuration in pressure mode, then switch to position mode.  This
 191  * gives a faster response time.  Even so, we need to wait about 55us
 192  * for things to stabilise.
 193  */
 194 static inline unsigned int ucb1400_ts_read_ypos(struct ucb1400 *ucb)
 195 {
 196         ucb1400_reg_write(ucb, UCB_TS_CR,
 197                         UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_POW |
 198                         UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA);
 199         ucb1400_reg_write(ucb, UCB_TS_CR,
 200                         UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_POW |
 201                         UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA);
 202         ucb1400_reg_write(ucb, UCB_TS_CR,
 203                         UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_POW |
 204                         UCB_TS_CR_MODE_POS | UCB_TS_CR_BIAS_ENA);
 205
 206         udelay(55);
 207
 208         return ucb1400_adc_read(ucb, UCB_ADC_INP_TSPX);
 209 }
 210
 211 /*
 212  * Switch to X plate resistance mode.  Set MX to ground, PX to
 213  * supply.  Measure current.
 214  */
 215 static inline unsigned int ucb1400_ts_read_xres(struct ucb1400 *ucb)
 216 {
 217         ucb1400_reg_write(ucb, UCB_TS_CR,
 218                         UCB_TS_CR_TSMX_GND | UCB_TS_CR_TSPX_POW |
 219                         UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA);
 220         return ucb1400_adc_read(ucb, 0);
 221 }
 222
 223 /*
 224  * Switch to Y plate resistance mode.  Set MY to ground, PY to
 225  * supply.  Measure current.
 226  */
 227 static inline unsigned int ucb1400_ts_read_yres(struct ucb1400 *ucb)
 228 {
 229         ucb1400_reg_write(ucb, UCB_TS_CR,
 230                         UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_POW |
 231                         UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA);
 232         return ucb1400_adc_read(ucb, 0);
 233 }
 234
 235 static inline int ucb1400_ts_pen_down(struct ucb1400 *ucb)
 236 {
 237         unsigned short val = ucb1400_reg_read(ucb, UCB_TS_CR);
 238         return (val & (UCB_TS_CR_TSPX_LOW | UCB_TS_CR_TSMX_LOW));
 239 }
 240
 241 static inline void ucb1400_ts_irq_enable(struct ucb1400 *ucb)
 242 {
 243         ucb1400_reg_write(ucb, UCB_IE_CLEAR, UCB_IE_TSPX);
 244         ucb1400_reg_write(ucb, UCB_IE_CLEAR, 0);
 245         ucb1400_reg_write(ucb, UCB_IE_FAL, UCB_IE_TSPX);
 246 }
 247
 248 static inline void ucb1400_ts_irq_disable(struct ucb1400 *ucb)
 249 {
 250         ucb1400_reg_write(ucb, UCB_IE_FAL, 0);
 251 }
 252
 253 static void ucb1400_ts_evt_add(struct input_dev *idev, u16 pressure, u16 x, u16 y)
 254 {
 255         input_report_abs(idev, ABS_X, x);
 256         input_report_abs(idev, ABS_Y, y);
 257         input_report_abs(idev, ABS_PRESSURE, pressure);
 258         input_sync(idev);
 259 }
 260
 261 static void ucb1400_ts_event_release(struct input_dev *idev)
 262 {
 263         input_report_abs(idev, ABS_PRESSURE, 0);
 264         input_sync(idev);
 265 }
 266
 267 static void ucb1400_handle_pending_irq(struct ucb1400 *ucb)
 268 {
 269         unsigned int isr;
 270
 271         isr = ucb1400_reg_read(ucb, UCB_IE_STATUS);
 272         ucb1400_reg_write(ucb, UCB_IE_CLEAR, isr);
 273         ucb1400_reg_write(ucb, UCB_IE_CLEAR, 0);
 274
 275         if (isr & UCB_IE_TSPX)
 276                 ucb1400_ts_irq_disable(ucb);
 277         else
 278                 printk(KERN_ERR "ucb1400: unexpected IE_STATUS = %#x\n", isr);
 279
 280         enable_irq(ucb->irq);
 281 }
 282
 283 static int ucb1400_ts_thread(void *_ucb)
 284 {
 285         struct ucb1400 *ucb = _ucb;
 286         struct task_struct *tsk = current;
 287         int valid = 0;
 288
 289         tsk->policy = SCHED_FIFO;
 290         tsk->rt_priority = 1;
 291
 292         while (!kthread_should_stop()) {
 293                 unsigned int x, y, p;
 294                 long timeout;
 295
 296                 ucb->ts_restart = 0;
 297
 298                 if (ucb->irq_pending) {
 299                         ucb->irq_pending = 0;
 300                         ucb1400_handle_pending_irq(ucb);
 301                 }
 302
 303                 ucb1400_adc_enable(ucb);
 304                 x = ucb1400_ts_read_xpos(ucb);
 305                 y = ucb1400_ts_read_ypos(ucb);
 306                 p = ucb1400_ts_read_pressure(ucb);
 307                 ucb1400_adc_disable(ucb);
 308
 309                 /* Switch back to interrupt mode. */
 310                 ucb1400_ts_mode_int(ucb);
 311
 312                 msleep(10);
 313
 314                 if (ucb1400_ts_pen_down(ucb)) {
 315                         ucb1400_ts_irq_enable(ucb);
 316
 317                         /*
 318                          * If we spat out a valid sample set last time,
 319                          * spit out a "pen off" sample here.
 320                          */
 321                         if (valid) {
 322                                 ucb1400_ts_event_release(ucb->ts_idev);
 323                                 valid = 0;
 324                         }
 325
 326                         timeout = MAX_SCHEDULE_TIMEOUT;
 327                 } else {
 328                         valid = 1;
 329                         ucb1400_ts_evt_add(ucb->ts_idev, p, x, y);
 330                         timeout = msecs_to_jiffies(10);
 331                 }
 332
 333                 wait_event_interruptible_timeout(ucb->ts_wait,
 334                         ucb->irq_pending || ucb->ts_restart || kthread_should_stop(),
 335                         timeout);
 336                 try_to_freeze();
 337         }
 338
 339         /* Send the "pen off" if we are stopping with the pen still active */
 340         if (valid)
 341                 ucb1400_ts_event_release(ucb->ts_idev);
 342
 343         ucb->ts_task = NULL;
 344         return 0;
 345 }
 346
 347 /*
 348  * A restriction with interrupts exists when using the ucb1400, as
 349  * the codec read/write routines may sleep while waiting for codec
 350  * access completion and uses semaphores for access control to the
 351  * AC97 bus.  A complete codec read cycle could take  anywhere from
 352  * 60 to 100uSec so we *definitely* don't want to spin inside the
 353  * interrupt handler waiting for codec access.  So, we handle the
 354  * interrupt by scheduling a RT kernel thread to run in process
 355  * context instead of interrupt context.
 356  */
 357 static irqreturn_t ucb1400_hard_irq(int irqnr, void *devid)
 358 {
 359         struct ucb1400 *ucb = devid;
 360
 361         if (irqnr == ucb->irq) {
 362                 disable_irq(ucb->irq);
 363                 ucb->irq_pending = 1;
 364                 wake_up(&ucb->ts_wait);
 365                 return IRQ_HANDLED;
 366         }
 367         return IRQ_NONE;
 368 }
 369
 370 static int ucb1400_ts_open(struct input_dev *idev)
 371 {
 372         struct ucb1400 *ucb = idev->private;
 373         int ret = 0;
 374
 375         BUG_ON(ucb->ts_task);
 376
 377         ucb->ts_task = kthread_run(ucb1400_ts_thread, ucb, "UCB1400_ts");
 378         if (IS_ERR(ucb->ts_task)) {
 379                 ret = PTR_ERR(ucb->ts_task);
 380                 ucb->ts_task = NULL;
 381         }
 382
 383         return ret;
 384 }
 385
 386 static void ucb1400_ts_close(struct input_dev *idev)
 387 {
 388         struct ucb1400 *ucb = idev->private;
 389
 390         if (ucb->ts_task)
 391                 kthread_stop(ucb->ts_task);
 392
 393         ucb1400_ts_irq_disable(ucb);
 394         ucb1400_reg_write(ucb, UCB_TS_CR, 0);
 395 }
 396
 397 #ifdef CONFIG_PM
 398 static int ucb1400_ts_resume(struct device *dev)
 399 {
 400         struct ucb1400 *ucb = dev_get_drvdata(dev);
 401
 402         if (ucb->ts_task) {
 403                 /*
 404                  * Restart the TS thread to ensure the
 405                  * TS interrupt mode is set up again
 406                  * after sleep.
 407                  */
 408                 ucb->ts_restart = 1;
 409                 wake_up(&ucb->ts_wait);
 410         }
 411         return 0;
 412 }
 413 #else
 414 #define ucb1400_ts_resume NULL
 415 #endif
 416
 417 #ifndef NO_IRQ
 418 #define NO_IRQ  0
 419 #endif
 420
 421 /*
 422  * Try to probe our interrupt, rather than relying on lots of
 423  * hard-coded machine dependencies.
 424  */
 425 static int ucb1400_detect_irq(struct ucb1400 *ucb)
 426 {
 427         unsigned long mask, timeout;
 428
 429         mask = probe_irq_on();
 430         if (!mask) {
 431                 probe_irq_off(mask);
 432                 return -EBUSY;
 433         }
 434
 435         /* Enable the ADC interrupt. */
 436         ucb1400_reg_write(ucb, UCB_IE_RIS, UCB_IE_ADC);
 437         ucb1400_reg_write(ucb, UCB_IE_FAL, UCB_IE_ADC);
 438         ucb1400_reg_write(ucb, UCB_IE_CLEAR, 0xffff);
 439         ucb1400_reg_write(ucb, UCB_IE_CLEAR, 0);
 440
 441         /* Cause an ADC interrupt. */
 442         ucb1400_reg_write(ucb, UCB_ADC_CR, UCB_ADC_ENA);
 443         ucb1400_reg_write(ucb, UCB_ADC_CR, UCB_ADC_ENA | UCB_ADC_START);
 444
 445         /* Wait for the conversion to complete. */
 446         timeout = jiffies + HZ/2;
 447         while (!(ucb1400_reg_read(ucb, UCB_ADC_DATA) & UCB_ADC_DAT_VALID)) {
 448                 cpu_relax();
 449                 if (time_after(jiffies, timeout)) {
 450                         printk(KERN_ERR "ucb1400: timed out in IRQ probe\n");
 451                         probe_irq_off(mask);
 452                         return -ENODEV;
 453                 }
 454         }
 455         ucb1400_reg_write(ucb, UCB_ADC_CR, 0);
 456
 457         /* Disable and clear interrupt. */
 458         ucb1400_reg_write(ucb, UCB_IE_RIS, 0);
 459         ucb1400_reg_write(ucb, UCB_IE_FAL, 0);
 460         ucb1400_reg_write(ucb, UCB_IE_CLEAR, 0xffff);
 461         ucb1400_reg_write(ucb, UCB_IE_CLEAR, 0);
 462
 463         /* Read triggered interrupt. */
 464         ucb->irq = probe_irq_off(mask);
 465         if (ucb->irq < 0 || ucb->irq == NO_IRQ)
 466                 return -ENODEV;
 467
 468         return 0;
 469 }
 470
 471 static int ucb1400_ts_probe(struct device *dev)
 472 {
 473         struct ucb1400 *ucb;
 474         struct input_dev *idev;
 475         int error, id, x_res, y_res;
 476
 477         ucb = kzalloc(sizeof(struct ucb1400), GFP_KERNEL);
 478         idev = input_allocate_device();
 479         if (!ucb || !idev) {
 480                 error = -ENOMEM;
 481                 goto err_free_devs;
 482         }
 483
 484         ucb->ts_idev = idev;
 485         ucb->adcsync = adcsync;
 486         ucb->ac97 = to_ac97_t(dev);
 487         init_waitqueue_head(&ucb->ts_wait);
 488
 489         id = ucb1400_reg_read(ucb, UCB_ID);
 490         if (id != UCB_ID_1400) {
 491                 error = -ENODEV;
 492                 goto err_free_devs;
 493         }
 494
 495         error = ucb1400_detect_irq(ucb);
 496         if (error) {
 497                 printk(KERN_ERR "UCB1400: IRQ probe failed\n");
 498                 goto err_free_devs;
 499         }
 500
 501         error = request_irq(ucb->irq, ucb1400_hard_irq, IRQF_TRIGGER_RISING,
 502                                 "UCB1400", ucb);
 503         if (error) {
 504                 printk(KERN_ERR "ucb1400: unable to grab irq%d: %d\n",
 505                                 ucb->irq, error);
 506                 goto err_free_devs;
 507         }
 508         printk(KERN_DEBUG "UCB1400: found IRQ %d\n", ucb->irq);
 509
 510         idev->private           = ucb;
 511         idev->cdev.dev          = dev;
 512         idev->name              = "UCB1400 touchscreen interface";
 513         idev->id.vendor         = ucb1400_reg_read(ucb, AC97_VENDOR_ID1);
 514         idev->id.product        = id;
 515         idev->open              = ucb1400_ts_open;
 516         idev->close             = ucb1400_ts_close;
 517         idev->evbit[0]          = BIT(EV_ABS);
 518
 519         ucb1400_adc_enable(ucb);
 520         x_res = ucb1400_ts_read_xres(ucb);
 521         y_res = ucb1400_ts_read_yres(ucb);
 522         ucb1400_adc_disable(ucb);
 523         printk(KERN_DEBUG "UCB1400: x/y = %d/%d\n", x_res, y_res);
 524
 525         input_set_abs_params(idev, ABS_X, 0, x_res, 0, 0);
 526         input_set_abs_params(idev, ABS_Y, 0, y_res, 0, 0);
 527         input_set_abs_params(idev, ABS_PRESSURE, 0, 0, 0, 0);
 528
 529         error = input_register_device(idev);
 530         if (error)
 531                 goto err_free_irq;
 532
 533         dev_set_drvdata(dev, ucb);
 534         return 0;
 535
 536  err_free_irq:
 537         free_irq(ucb->irq, ucb);
 538  err_free_devs:
 539         input_free_device(idev);
 540         kfree(ucb);
 541         return error;
 542 }
 543
 544 static int ucb1400_ts_remove(struct device *dev)
 545 {
 546         struct ucb1400 *ucb = dev_get_drvdata(dev);
 547
 548         free_irq(ucb->irq, ucb);
 549         input_unregister_device(ucb->ts_idev);
 550         dev_set_drvdata(dev, NULL);
 551         kfree(ucb);
 552         return 0;
 553 }
 554
 555 static struct device_driver ucb1400_ts_driver = {
 556         .owner          = THIS_MODULE,
 557         .bus            = &ac97_bus_type,
 558         .probe          = ucb1400_ts_probe,
 559         .remove         = ucb1400_ts_remove,
 560         .resume         = ucb1400_ts_resume,
 561 };
 562
 563 static int __init ucb1400_ts_init(void)
 564 {
 565         return driver_register(&ucb1400_ts_driver);
 566 }
 567
 568 static void __exit ucb1400_ts_exit(void)
 569 {
 570         driver_unregister(&ucb1400_ts_driver);
 571 }
 572
 573 module_param(adcsync, int, 0444);
 574
 575 module_init(ucb1400_ts_init);
 576 module_exit(ucb1400_ts_exit);
 577
 578 MODULE_DESCRIPTION("Philips UCB1400 touchscreen driver");
 579 MODULE_LICENSE("GPL");