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  * Spliting done by: Marek Vasut <marek.vasut@gmail.com>
   9  * If something doesn't work and it worked before spliting, e-mail me,
  10  * dont bother Nicolas please ;-)
  11  *
  12  * This program is free software; you can redistribute it and/or modify
  13  * it under the terms of the GNU General Public License version 2 as
  14  * published by the Free Software Foundation.
  15  *
  16  * This code is heavily based on ucb1x00-*.c copyrighted by Russell King
  17  * covering the UCB1100, UCB1200 and UCB1300..  Support for the UCB1400 has
  18  * been made separate from ucb1x00-core/ucb1x00-ts on Russell's request.
  19  */
  20
  21 #include <linux/module.h>
  22 #include <linux/init.h>
  23 #include <linux/completion.h>
  24 #include <linux/delay.h>
  25 #include <linux/input.h>
  26 #include <linux/device.h>
  27 #include <linux/interrupt.h>
  28 #include <linux/suspend.h>
  29 #include <linux/kthread.h>
  30 #include <linux/freezer.h>
  31 #include <linux/ucb1400.h>
  32
  33 static int adcsync;
  34 static int ts_delay = 55; /* us */
  35 static int ts_delay_pressure;   /* us */
  36
  37 /* Switch to interrupt mode. */
  38 static inline void ucb1400_ts_mode_int(struct snd_ac97 *ac97)
  39 {
  40         ucb1400_reg_write(ac97, UCB_TS_CR,
  41                         UCB_TS_CR_TSMX_POW | UCB_TS_CR_TSPX_POW |
  42                         UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_GND |
  43                         UCB_TS_CR_MODE_INT);
  44 }
  45
  46 /*
  47  * Switch to pressure mode, and read pressure.  We don't need to wait
  48  * here, since both plates are being driven.
  49  */
  50 static inline unsigned int ucb1400_ts_read_pressure(struct ucb1400_ts *ucb)
  51 {
  52         ucb1400_reg_write(ucb->ac97, UCB_TS_CR,
  53                         UCB_TS_CR_TSMX_POW | UCB_TS_CR_TSPX_POW |
  54                         UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_GND |
  55                         UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA);
  56         udelay(ts_delay_pressure);
  57         return ucb1400_adc_read(ucb->ac97, UCB_ADC_INP_TSPY, adcsync);
  58 }
  59
  60 /*
  61  * Switch to X position mode and measure Y plate.  We switch the plate
  62  * configuration in pressure mode, then switch to position mode.  This
  63  * gives a faster response time.  Even so, we need to wait about 55us
  64  * for things to stabilise.
  65  */
  66 static inline unsigned int ucb1400_ts_read_xpos(struct ucb1400_ts *ucb)
  67 {
  68         ucb1400_reg_write(ucb->ac97, UCB_TS_CR,
  69                         UCB_TS_CR_TSMX_GND | UCB_TS_CR_TSPX_POW |
  70                         UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA);
  71         ucb1400_reg_write(ucb->ac97, UCB_TS_CR,
  72                         UCB_TS_CR_TSMX_GND | UCB_TS_CR_TSPX_POW |
  73                         UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA);
  74         ucb1400_reg_write(ucb->ac97, UCB_TS_CR,
  75                         UCB_TS_CR_TSMX_GND | UCB_TS_CR_TSPX_POW |
  76                         UCB_TS_CR_MODE_POS | UCB_TS_CR_BIAS_ENA);
  77
  78         udelay(ts_delay);
  79
  80         return ucb1400_adc_read(ucb->ac97, UCB_ADC_INP_TSPY, adcsync);
  81 }
  82
  83 /*
  84  * Switch to Y position mode and measure X plate.  We switch the plate
  85  * configuration in pressure mode, then switch to position mode.  This
  86  * gives a faster response time.  Even so, we need to wait about 55us
  87  * for things to stabilise.
  88  */
  89 static inline unsigned int ucb1400_ts_read_ypos(struct ucb1400_ts *ucb)
  90 {
  91         ucb1400_reg_write(ucb->ac97, UCB_TS_CR,
  92                         UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_POW |
  93                         UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA);
  94         ucb1400_reg_write(ucb->ac97, UCB_TS_CR,
  95                         UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_POW |
  96                         UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA);
  97         ucb1400_reg_write(ucb->ac97, UCB_TS_CR,
  98                         UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_POW |
  99                         UCB_TS_CR_MODE_POS | UCB_TS_CR_BIAS_ENA);
 100
 101         udelay(ts_delay);
 102
 103         return ucb1400_adc_read(ucb->ac97, UCB_ADC_INP_TSPX, adcsync);
 104 }
 105
 106 /*
 107  * Switch to X plate resistance mode.  Set MX to ground, PX to
 108  * supply.  Measure current.
 109  */
 110 static inline unsigned int ucb1400_ts_read_xres(struct ucb1400_ts *ucb)
 111 {
 112         ucb1400_reg_write(ucb->ac97, UCB_TS_CR,
 113                         UCB_TS_CR_TSMX_GND | UCB_TS_CR_TSPX_POW |
 114                         UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA);
 115         return ucb1400_adc_read(ucb->ac97, 0, adcsync);
 116 }
 117
 118 /*
 119  * Switch to Y plate resistance mode.  Set MY to ground, PY to
 120  * supply.  Measure current.
 121  */
 122 static inline unsigned int ucb1400_ts_read_yres(struct ucb1400_ts *ucb)
 123 {
 124         ucb1400_reg_write(ucb->ac97, UCB_TS_CR,
 125                         UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_POW |
 126                         UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA);
 127         return ucb1400_adc_read(ucb->ac97, 0, adcsync);
 128 }
 129
 130 static inline int ucb1400_ts_pen_up(struct snd_ac97 *ac97)
 131 {
 132         unsigned short val = ucb1400_reg_read(ac97, UCB_TS_CR);
 133
 134         return val & (UCB_TS_CR_TSPX_LOW | UCB_TS_CR_TSMX_LOW);
 135 }
 136
 137 static inline void ucb1400_ts_irq_enable(struct snd_ac97 *ac97)
 138 {
 139         ucb1400_reg_write(ac97, UCB_IE_CLEAR, UCB_IE_TSPX);
 140         ucb1400_reg_write(ac97, UCB_IE_CLEAR, 0);
 141         ucb1400_reg_write(ac97, UCB_IE_FAL, UCB_IE_TSPX);
 142 }
 143
 144 static inline void ucb1400_ts_irq_disable(struct snd_ac97 *ac97)
 145 {
 146         ucb1400_reg_write(ac97, UCB_IE_FAL, 0);
 147 }
 148
 149 static void ucb1400_ts_evt_add(struct input_dev *idev, u16 pressure, u16 x, u16 y)
 150 {
 151         input_report_abs(idev, ABS_X, x);
 152         input_report_abs(idev, ABS_Y, y);
 153         input_report_abs(idev, ABS_PRESSURE, pressure);
 154         input_report_key(idev, BTN_TOUCH, 1);
 155         input_sync(idev);
 156 }
 157
 158 static void ucb1400_ts_event_release(struct input_dev *idev)
 159 {
 160         input_report_abs(idev, ABS_PRESSURE, 0);
 161         input_report_key(idev, BTN_TOUCH, 0);
 162         input_sync(idev);
 163 }
 164
 165 static void ucb1400_handle_pending_irq(struct ucb1400_ts *ucb)
 166 {
 167         unsigned int isr;
 168
 169         isr = ucb1400_reg_read(ucb->ac97, UCB_IE_STATUS);
 170         ucb1400_reg_write(ucb->ac97, UCB_IE_CLEAR, isr);
 171         ucb1400_reg_write(ucb->ac97, UCB_IE_CLEAR, 0);
 172
 173         if (isr & UCB_IE_TSPX)
 174                 ucb1400_ts_irq_disable(ucb->ac97);
 175         else
 176                 dev_dbg(&ucb->ts_idev->dev, "ucb1400: unexpected IE_STATUS = %#x\n", isr);
 177         enable_irq(ucb->irq);
 178 }
 179
 180 static int ucb1400_ts_thread(void *_ucb)
 181 {
 182         struct ucb1400_ts *ucb = _ucb;
 183         struct task_struct *tsk = current;
 184         int valid = 0;
 185         struct sched_param param = { .sched_priority = 1 };
 186
 187         sched_setscheduler(tsk, SCHED_FIFO, &param);
 188
 189         set_freezable();
 190         while (!kthread_should_stop()) {
 191                 unsigned int x, y, p;
 192                 long timeout;
 193
 194                 ucb->ts_restart = 0;
 195
 196                 if (ucb->irq_pending) {
 197                         ucb->irq_pending = 0;
 198                         ucb1400_handle_pending_irq(ucb);
 199                 }
 200
 201                 ucb1400_adc_enable(ucb->ac97);
 202                 x = ucb1400_ts_read_xpos(ucb);
 203                 y = ucb1400_ts_read_ypos(ucb);
 204                 p = ucb1400_ts_read_pressure(ucb);
 205                 ucb1400_adc_disable(ucb->ac97);
 206
 207                 /* Switch back to interrupt mode. */
 208                 ucb1400_ts_mode_int(ucb->ac97);
 209
 210                 msleep(10);
 211
 212                 if (ucb1400_ts_pen_up(ucb->ac97)) {
 213                         ucb1400_ts_irq_enable(ucb->ac97);
 214
 215                         /*
 216                          * If we spat out a valid sample set last time,
 217                          * spit out a "pen off" sample here.
 218                          */
 219                         if (valid) {
 220                                 ucb1400_ts_event_release(ucb->ts_idev);
 221                                 valid = 0;
 222                         }
 223
 224                         timeout = MAX_SCHEDULE_TIMEOUT;
 225                 } else {
 226                         valid = 1;
 227                         ucb1400_ts_evt_add(ucb->ts_idev, p, x, y);
 228                         timeout = msecs_to_jiffies(10);
 229                 }
 230
 231                 wait_event_freezable_timeout(ucb->ts_wait,
 232                         ucb->irq_pending || ucb->ts_restart ||
 233                         kthread_should_stop(), timeout);
 234         }
 235
 236         /* Send the "pen off" if we are stopping with the pen still active */
 237         if (valid)
 238                 ucb1400_ts_event_release(ucb->ts_idev);
 239
 240         ucb->ts_task = NULL;
 241         return 0;
 242 }
 243
 244 /*
 245  * A restriction with interrupts exists when using the ucb1400, as
 246  * the codec read/write routines may sleep while waiting for codec
 247  * access completion and uses semaphores for access control to the
 248  * AC97 bus.  A complete codec read cycle could take  anywhere from
 249  * 60 to 100uSec so we *definitely* don't want to spin inside the
 250  * interrupt handler waiting for codec access.  So, we handle the
 251  * interrupt by scheduling a RT kernel thread to run in process
 252  * context instead of interrupt context.
 253  */
 254 static irqreturn_t ucb1400_hard_irq(int irqnr, void *devid)
 255 {
 256         struct ucb1400_ts *ucb = devid;
 257
 258         if (irqnr == ucb->irq) {
 259                 disable_irq_nosync(ucb->irq);
 260                 ucb->irq_pending = 1;
 261                 wake_up(&ucb->ts_wait);
 262                 return IRQ_HANDLED;
 263         }
 264         return IRQ_NONE;
 265 }
 266
 267 static int ucb1400_ts_open(struct input_dev *idev)
 268 {
 269         struct ucb1400_ts *ucb = input_get_drvdata(idev);
 270         int ret = 0;
 271
 272         BUG_ON(ucb->ts_task);
 273
 274         ucb->ts_task = kthread_run(ucb1400_ts_thread, ucb, "UCB1400_ts");
 275         if (IS_ERR(ucb->ts_task)) {
 276                 ret = PTR_ERR(ucb->ts_task);
 277                 ucb->ts_task = NULL;
 278         }
 279
 280         return ret;
 281 }
 282
 283 static void ucb1400_ts_close(struct input_dev *idev)
 284 {
 285         struct ucb1400_ts *ucb = input_get_drvdata(idev);
 286
 287         if (ucb->ts_task)
 288                 kthread_stop(ucb->ts_task);
 289
 290         ucb1400_ts_irq_disable(ucb->ac97);
 291         ucb1400_reg_write(ucb->ac97, UCB_TS_CR, 0);
 292 }
 293
 294 #ifndef NO_IRQ
 295 #define NO_IRQ  0
 296 #endif
 297
 298 /*
 299  * Try to probe our interrupt, rather than relying on lots of
 300  * hard-coded machine dependencies.
 301  */
 302 static int ucb1400_ts_detect_irq(struct ucb1400_ts *ucb)
 303 {
 304         unsigned long mask, timeout;
 305
 306         mask = probe_irq_on();
 307
 308         /* Enable the ADC interrupt. */
 309         ucb1400_reg_write(ucb->ac97, UCB_IE_RIS, UCB_IE_ADC);
 310         ucb1400_reg_write(ucb->ac97, UCB_IE_FAL, UCB_IE_ADC);
 311         ucb1400_reg_write(ucb->ac97, UCB_IE_CLEAR, 0xffff);
 312         ucb1400_reg_write(ucb->ac97, UCB_IE_CLEAR, 0);
 313
 314         /* Cause an ADC interrupt. */
 315         ucb1400_reg_write(ucb->ac97, UCB_ADC_CR, UCB_ADC_ENA);
 316         ucb1400_reg_write(ucb->ac97, UCB_ADC_CR, UCB_ADC_ENA | UCB_ADC_START);
 317
 318         /* Wait for the conversion to complete. */
 319         timeout = jiffies + HZ/2;
 320         while (!(ucb1400_reg_read(ucb->ac97, UCB_ADC_DATA) &
 321                                                 UCB_ADC_DAT_VALID)) {
 322                 cpu_relax();
 323                 if (time_after(jiffies, timeout)) {
 324                         printk(KERN_ERR "ucb1400: timed out in IRQ probe\n");
 325                         probe_irq_off(mask);
 326                         return -ENODEV;
 327                 }
 328         }
 329         ucb1400_reg_write(ucb->ac97, UCB_ADC_CR, 0);
 330
 331         /* Disable and clear interrupt. */
 332         ucb1400_reg_write(ucb->ac97, UCB_IE_RIS, 0);
 333         ucb1400_reg_write(ucb->ac97, UCB_IE_FAL, 0);
 334         ucb1400_reg_write(ucb->ac97, UCB_IE_CLEAR, 0xffff);
 335         ucb1400_reg_write(ucb->ac97, UCB_IE_CLEAR, 0);
 336
 337         /* Read triggered interrupt. */
 338         ucb->irq = probe_irq_off(mask);
 339         if (ucb->irq < 0 || ucb->irq == NO_IRQ)
 340                 return -ENODEV;
 341
 342         return 0;
 343 }
 344
 345 static int ucb1400_ts_probe(struct platform_device *dev)
 346 {
 347         int error, x_res, y_res;
 348         u16 fcsr;
 349         struct ucb1400_ts *ucb = dev->dev.platform_data;
 350
 351         ucb->ts_idev = input_allocate_device();
 352         if (!ucb->ts_idev) {
 353                 error = -ENOMEM;
 354                 goto err;
 355         }
 356
 357         /* Only in case the IRQ line wasn't supplied, try detecting it */
 358         if (ucb->irq < 0) {
 359                 error = ucb1400_ts_detect_irq(ucb);
 360                 if (error) {
 361                         printk(KERN_ERR "UCB1400: IRQ probe failed\n");
 362                         goto err_free_devs;
 363                 }
 364         }
 365
 366         init_waitqueue_head(&ucb->ts_wait);
 367
 368         error = request_irq(ucb->irq, ucb1400_hard_irq, IRQF_TRIGGER_RISING,
 369                                 "UCB1400", ucb);
 370         if (error) {
 371                 printk(KERN_ERR "ucb1400: unable to grab irq%d: %d\n",
 372                                 ucb->irq, error);
 373                 goto err_free_devs;
 374         }
 375         printk(KERN_DEBUG "UCB1400: found IRQ %d\n", ucb->irq);
 376
 377         input_set_drvdata(ucb->ts_idev, ucb);
 378
 379         ucb->ts_idev->dev.parent        = &dev->dev;
 380         ucb->ts_idev->name              = "UCB1400 touchscreen interface";
 381         ucb->ts_idev->id.vendor         = ucb1400_reg_read(ucb->ac97,
 382                                                 AC97_VENDOR_ID1);
 383         ucb->ts_idev->id.product        = ucb->id;
 384         ucb->ts_idev->open              = ucb1400_ts_open;
 385         ucb->ts_idev->close             = ucb1400_ts_close;
 386         ucb->ts_idev->evbit[0]          = BIT_MASK(EV_ABS) | BIT_MASK(EV_KEY);
 387         ucb->ts_idev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
 388
 389         /*
 390          * Enable ADC filter to prevent horrible jitter on Colibri.
 391          * This also further reduces jitter on boards where ADCSYNC
 392          * pin is connected.
 393          */
 394         fcsr = ucb1400_reg_read(ucb->ac97, UCB_FCSR);
 395         ucb1400_reg_write(ucb->ac97, UCB_FCSR, fcsr | UCB_FCSR_AVE);
 396
 397         ucb1400_adc_enable(ucb->ac97);
 398         x_res = ucb1400_ts_read_xres(ucb);
 399         y_res = ucb1400_ts_read_yres(ucb);
 400         ucb1400_adc_disable(ucb->ac97);
 401         printk(KERN_DEBUG "UCB1400: x/y = %d/%d\n", x_res, y_res);
 402
 403         input_set_abs_params(ucb->ts_idev, ABS_X, 0, x_res, 0, 0);
 404         input_set_abs_params(ucb->ts_idev, ABS_Y, 0, y_res, 0, 0);
 405         input_set_abs_params(ucb->ts_idev, ABS_PRESSURE, 0, 0, 0, 0);
 406
 407         error = input_register_device(ucb->ts_idev);
 408         if (error)
 409                 goto err_free_irq;
 410
 411         return 0;
 412
 413 err_free_irq:
 414         free_irq(ucb->irq, ucb);
 415 err_free_devs:
 416         input_free_device(ucb->ts_idev);
 417 err:
 418         return error;
 419
 420 }
 421
 422 static int ucb1400_ts_remove(struct platform_device *dev)
 423 {
 424         struct ucb1400_ts *ucb = dev->dev.platform_data;
 425
 426         free_irq(ucb->irq, ucb);
 427         input_unregister_device(ucb->ts_idev);
 428         return 0;
 429 }
 430
 431 #ifdef CONFIG_PM
 432 static int ucb1400_ts_resume(struct platform_device *dev)
 433 {
 434         struct ucb1400_ts *ucb = dev->dev.platform_data;
 435
 436         if (ucb->ts_task) {
 437                 /*
 438                  * Restart the TS thread to ensure the
 439                  * TS interrupt mode is set up again
 440                  * after sleep.
 441                  */
 442                 ucb->ts_restart = 1;
 443                 wake_up(&ucb->ts_wait);
 444         }
 445         return 0;
 446 }
 447 #else
 448 #define ucb1400_ts_resume NULL
 449 #endif
 450
 451 static struct platform_driver ucb1400_ts_driver = {
 452         .probe  = ucb1400_ts_probe,
 453         .remove = ucb1400_ts_remove,
 454         .resume = ucb1400_ts_resume,
 455         .driver = {
 456                 .name   = "ucb1400_ts",
 457         },
 458 };
 459
 460 static int __init ucb1400_ts_init(void)
 461 {
 462         return platform_driver_register(&ucb1400_ts_driver);
 463 }
 464
 465 static void __exit ucb1400_ts_exit(void)
 466 {
 467         platform_driver_unregister(&ucb1400_ts_driver);
 468 }
 469
 470 module_param(adcsync, bool, 0444);
 471 MODULE_PARM_DESC(adcsync, "Synchronize touch readings with ADCSYNC pin.");
 472
 473 module_param(ts_delay, int, 0444);
 474 MODULE_PARM_DESC(ts_delay, "Delay between panel setup and"
 475                             " position read. Default = 55us.");
 476
 477 module_param(ts_delay_pressure, int, 0444);
 478 MODULE_PARM_DESC(ts_delay_pressure,
 479                 "delay between panel setup and pressure read."
 480                 "  Default = 0us.");
 481
 482 module_init(ucb1400_ts_init);
 483 module_exit(ucb1400_ts_exit);
 484
 485 MODULE_DESCRIPTION("Philips UCB1400 touchscreen driver");
 486 MODULE_LICENSE("GPL");