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/delay.h>
  23 #include <linux/sched.h>
  24 #include <linux/wait.h>
  25 #include <linux/input.h>
  26 #include <linux/device.h>
  27 #include <linux/interrupt.h>
  28 #include <linux/ucb1400.h>
  29
  30 #define UCB1400_TS_POLL_PERIOD  10 /* ms */
  31
  32 static bool adcsync;
  33 static int ts_delay = 55; /* us */
  34 static int ts_delay_pressure;   /* us */
  35
  36 /* Switch to interrupt mode. */
  37 static void ucb1400_ts_mode_int(struct ucb1400_ts *ucb)
  38 {
  39         ucb1400_reg_write(ucb->ac97, UCB_TS_CR,
  40                         UCB_TS_CR_TSMX_POW | UCB_TS_CR_TSPX_POW |
  41                         UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_GND |
  42                         UCB_TS_CR_MODE_INT);
  43 }
  44
  45 /*
  46  * Switch to pressure mode, and read pressure.  We don't need to wait
  47  * here, since both plates are being driven.
  48  */
  49 static unsigned int ucb1400_ts_read_pressure(struct ucb1400_ts *ucb)
  50 {
  51         ucb1400_reg_write(ucb->ac97, UCB_TS_CR,
  52                         UCB_TS_CR_TSMX_POW | UCB_TS_CR_TSPX_POW |
  53                         UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_GND |
  54                         UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA);
  55
  56         udelay(ts_delay_pressure);
  57
  58         return ucb1400_adc_read(ucb->ac97, UCB_ADC_INP_TSPY, adcsync);
  59 }
  60
  61 /*
  62  * Switch to X position mode and measure Y plate.  We switch the plate
  63  * configuration in pressure mode, then switch to position mode.  This
  64  * gives a faster response time.  Even so, we need to wait about 55us
  65  * for things to stabilise.
  66  */
  67 static unsigned int ucb1400_ts_read_xpos(struct ucb1400_ts *ucb)
  68 {
  69         ucb1400_reg_write(ucb->ac97, UCB_TS_CR,
  70                         UCB_TS_CR_TSMX_GND | UCB_TS_CR_TSPX_POW |
  71                         UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA);
  72         ucb1400_reg_write(ucb->ac97, UCB_TS_CR,
  73                         UCB_TS_CR_TSMX_GND | UCB_TS_CR_TSPX_POW |
  74                         UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA);
  75         ucb1400_reg_write(ucb->ac97, UCB_TS_CR,
  76                         UCB_TS_CR_TSMX_GND | UCB_TS_CR_TSPX_POW |
  77                         UCB_TS_CR_MODE_POS | UCB_TS_CR_BIAS_ENA);
  78
  79         udelay(ts_delay);
  80
  81         return ucb1400_adc_read(ucb->ac97, UCB_ADC_INP_TSPY, adcsync);
  82 }
  83
  84 /*
  85  * Switch to Y position mode and measure X plate.  We switch the plate
  86  * configuration in pressure mode, then switch to position mode.  This
  87  * gives a faster response time.  Even so, we need to wait about 55us
  88  * for things to stabilise.
  89  */
  90 static int ucb1400_ts_read_ypos(struct ucb1400_ts *ucb)
  91 {
  92         ucb1400_reg_write(ucb->ac97, UCB_TS_CR,
  93                         UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_POW |
  94                         UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA);
  95         ucb1400_reg_write(ucb->ac97, UCB_TS_CR,
  96                         UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_POW |
  97                         UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA);
  98         ucb1400_reg_write(ucb->ac97, UCB_TS_CR,
  99                         UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_POW |
 100                         UCB_TS_CR_MODE_POS | UCB_TS_CR_BIAS_ENA);
 101
 102         udelay(ts_delay);
 103
 104         return ucb1400_adc_read(ucb->ac97, UCB_ADC_INP_TSPX, adcsync);
 105 }
 106
 107 /*
 108  * Switch to X plate resistance mode.  Set MX to ground, PX to
 109  * supply.  Measure current.
 110  */
 111 static unsigned int ucb1400_ts_read_xres(struct ucb1400_ts *ucb)
 112 {
 113         ucb1400_reg_write(ucb->ac97, UCB_TS_CR,
 114                         UCB_TS_CR_TSMX_GND | UCB_TS_CR_TSPX_POW |
 115                         UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA);
 116         return ucb1400_adc_read(ucb->ac97, 0, adcsync);
 117 }
 118
 119 /*
 120  * Switch to Y plate resistance mode.  Set MY to ground, PY to
 121  * supply.  Measure current.
 122  */
 123 static unsigned int ucb1400_ts_read_yres(struct ucb1400_ts *ucb)
 124 {
 125         ucb1400_reg_write(ucb->ac97, UCB_TS_CR,
 126                         UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_POW |
 127                         UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA);
 128         return ucb1400_adc_read(ucb->ac97, 0, adcsync);
 129 }
 130
 131 static int ucb1400_ts_pen_up(struct ucb1400_ts *ucb)
 132 {
 133         unsigned short val = ucb1400_reg_read(ucb->ac97, UCB_TS_CR);
 134
 135         return val & (UCB_TS_CR_TSPX_LOW | UCB_TS_CR_TSMX_LOW);
 136 }
 137
 138 static void ucb1400_ts_irq_enable(struct ucb1400_ts *ucb)
 139 {
 140         ucb1400_reg_write(ucb->ac97, UCB_IE_CLEAR, UCB_IE_TSPX);
 141         ucb1400_reg_write(ucb->ac97, UCB_IE_CLEAR, 0);
 142         ucb1400_reg_write(ucb->ac97, UCB_IE_FAL, UCB_IE_TSPX);
 143 }
 144
 145 static void ucb1400_ts_irq_disable(struct ucb1400_ts *ucb)
 146 {
 147         ucb1400_reg_write(ucb->ac97, UCB_IE_FAL, 0);
 148 }
 149
 150 static void ucb1400_ts_report_event(struct input_dev *idev, u16 pressure, u16 x, u16 y)
 151 {
 152         input_report_abs(idev, ABS_X, x);
 153         input_report_abs(idev, ABS_Y, y);
 154         input_report_abs(idev, ABS_PRESSURE, pressure);
 155         input_report_key(idev, BTN_TOUCH, 1);
 156         input_sync(idev);
 157 }
 158
 159 static void ucb1400_ts_event_release(struct input_dev *idev)
 160 {
 161         input_report_abs(idev, ABS_PRESSURE, 0);
 162         input_report_key(idev, BTN_TOUCH, 0);
 163         input_sync(idev);
 164 }
 165
 166 static void ucb1400_clear_pending_irq(struct ucb1400_ts *ucb)
 167 {
 168         unsigned int isr;
 169
 170         isr = ucb1400_reg_read(ucb->ac97, UCB_IE_STATUS);
 171         ucb1400_reg_write(ucb->ac97, UCB_IE_CLEAR, isr);
 172         ucb1400_reg_write(ucb->ac97, UCB_IE_CLEAR, 0);
 173
 174         if (isr & UCB_IE_TSPX)
 175                 ucb1400_ts_irq_disable(ucb);
 176         else
 177                 dev_dbg(&ucb->ts_idev->dev,
 178                         "ucb1400: unexpected IE_STATUS = %#x\n", isr);
 179 }
 180
 181 /*
 182  * A restriction with interrupts exists when using the ucb1400, as
 183  * the codec read/write routines may sleep while waiting for codec
 184  * access completion and uses semaphores for access control to the
 185  * AC97 bus. Therefore the driver is forced to use threaded interrupt
 186  * handler.
 187  */
 188 static irqreturn_t ucb1400_irq(int irqnr, void *devid)
 189 {
 190         struct ucb1400_ts *ucb = devid;
 191         unsigned int x, y, p;
 192         bool penup;
 193
 194         if (unlikely(irqnr != ucb->irq))
 195                 return IRQ_NONE;
 196
 197         ucb1400_clear_pending_irq(ucb);
 198
 199         /* Start with a small delay before checking pendown state */
 200         msleep(UCB1400_TS_POLL_PERIOD);
 201
 202         while (!ucb->stopped && !(penup = ucb1400_ts_pen_up(ucb))) {
 203
 204                 ucb1400_adc_enable(ucb->ac97);
 205                 x = ucb1400_ts_read_xpos(ucb);
 206                 y = ucb1400_ts_read_ypos(ucb);
 207                 p = ucb1400_ts_read_pressure(ucb);
 208                 ucb1400_adc_disable(ucb->ac97);
 209
 210                 ucb1400_ts_report_event(ucb->ts_idev, p, x, y);
 211
 212                 wait_event_timeout(ucb->ts_wait, ucb->stopped,
 213                                    msecs_to_jiffies(UCB1400_TS_POLL_PERIOD));
 214         }
 215
 216         ucb1400_ts_event_release(ucb->ts_idev);
 217
 218         if (!ucb->stopped) {
 219                 /* Switch back to interrupt mode. */
 220                 ucb1400_ts_mode_int(ucb);
 221                 ucb1400_ts_irq_enable(ucb);
 222         }
 223
 224         return IRQ_HANDLED;
 225 }
 226
 227 static void ucb1400_ts_stop(struct ucb1400_ts *ucb)
 228 {
 229         /* Signal IRQ thread to stop polling and disable the handler. */
 230         ucb->stopped = true;
 231         mb();
 232         wake_up(&ucb->ts_wait);
 233         disable_irq(ucb->irq);
 234
 235         ucb1400_ts_irq_disable(ucb);
 236         ucb1400_reg_write(ucb->ac97, UCB_TS_CR, 0);
 237 }
 238
 239 /* Must be called with ts->lock held */
 240 static void ucb1400_ts_start(struct ucb1400_ts *ucb)
 241 {
 242         /* Tell IRQ thread that it may poll the device. */
 243         ucb->stopped = false;
 244         mb();
 245
 246         ucb1400_ts_mode_int(ucb);
 247         ucb1400_ts_irq_enable(ucb);
 248
 249         enable_irq(ucb->irq);
 250 }
 251
 252 static int ucb1400_ts_open(struct input_dev *idev)
 253 {
 254         struct ucb1400_ts *ucb = input_get_drvdata(idev);
 255
 256         ucb1400_ts_start(ucb);
 257
 258         return 0;
 259 }
 260
 261 static void ucb1400_ts_close(struct input_dev *idev)
 262 {
 263         struct ucb1400_ts *ucb = input_get_drvdata(idev);
 264
 265         ucb1400_ts_stop(ucb);
 266 }
 267
 268 #ifndef NO_IRQ
 269 #define NO_IRQ  0
 270 #endif
 271
 272 /*
 273  * Try to probe our interrupt, rather than relying on lots of
 274  * hard-coded machine dependencies.
 275  */
 276 static int ucb1400_ts_detect_irq(struct ucb1400_ts *ucb,
 277                                            struct platform_device *pdev)
 278 {
 279         unsigned long mask, timeout;
 280
 281         mask = probe_irq_on();
 282
 283         /* Enable the ADC interrupt. */
 284         ucb1400_reg_write(ucb->ac97, UCB_IE_RIS, UCB_IE_ADC);
 285         ucb1400_reg_write(ucb->ac97, UCB_IE_FAL, UCB_IE_ADC);
 286         ucb1400_reg_write(ucb->ac97, UCB_IE_CLEAR, 0xffff);
 287         ucb1400_reg_write(ucb->ac97, UCB_IE_CLEAR, 0);
 288
 289         /* Cause an ADC interrupt. */
 290         ucb1400_reg_write(ucb->ac97, UCB_ADC_CR, UCB_ADC_ENA);
 291         ucb1400_reg_write(ucb->ac97, UCB_ADC_CR, UCB_ADC_ENA | UCB_ADC_START);
 292
 293         /* Wait for the conversion to complete. */
 294         timeout = jiffies + HZ/2;
 295         while (!(ucb1400_reg_read(ucb->ac97, UCB_ADC_DATA) &
 296                                                 UCB_ADC_DAT_VALID)) {
 297                 cpu_relax();
 298                 if (time_after(jiffies, timeout)) {
 299                         dev_err(&pdev->dev, "timed out in IRQ probe\n");
 300                         probe_irq_off(mask);
 301                         return -ENODEV;
 302                 }
 303         }
 304         ucb1400_reg_write(ucb->ac97, UCB_ADC_CR, 0);
 305
 306         /* Disable and clear interrupt. */
 307         ucb1400_reg_write(ucb->ac97, UCB_IE_RIS, 0);
 308         ucb1400_reg_write(ucb->ac97, UCB_IE_FAL, 0);
 309         ucb1400_reg_write(ucb->ac97, UCB_IE_CLEAR, 0xffff);
 310         ucb1400_reg_write(ucb->ac97, UCB_IE_CLEAR, 0);
 311
 312         /* Read triggered interrupt. */
 313         ucb->irq = probe_irq_off(mask);
 314         if (ucb->irq < 0 || ucb->irq == NO_IRQ)
 315                 return -ENODEV;
 316
 317         return 0;
 318 }
 319
 320 static int ucb1400_ts_probe(struct platform_device *pdev)
 321 {
 322         struct ucb1400_ts *ucb = dev_get_platdata(&pdev->dev);
 323         int error, x_res, y_res;
 324         u16 fcsr;
 325
 326         ucb->ts_idev = input_allocate_device();
 327         if (!ucb->ts_idev) {
 328                 error = -ENOMEM;
 329                 goto err;
 330         }
 331
 332         /* Only in case the IRQ line wasn't supplied, try detecting it */
 333         if (ucb->irq < 0) {
 334                 error = ucb1400_ts_detect_irq(ucb, pdev);
 335                 if (error) {
 336                         dev_err(&pdev->dev, "IRQ probe failed\n");
 337                         goto err_free_devs;
 338                 }
 339         }
 340         dev_dbg(&pdev->dev, "found IRQ %d\n", ucb->irq);
 341
 342         init_waitqueue_head(&ucb->ts_wait);
 343
 344         input_set_drvdata(ucb->ts_idev, ucb);
 345
 346         ucb->ts_idev->dev.parent        = &pdev->dev;
 347         ucb->ts_idev->name              = "UCB1400 touchscreen interface";
 348         ucb->ts_idev->id.vendor         = ucb1400_reg_read(ucb->ac97,
 349                                                 AC97_VENDOR_ID1);
 350         ucb->ts_idev->id.product        = ucb->id;
 351         ucb->ts_idev->open              = ucb1400_ts_open;
 352         ucb->ts_idev->close             = ucb1400_ts_close;
 353         ucb->ts_idev->evbit[0]          = BIT_MASK(EV_ABS) | BIT_MASK(EV_KEY);
 354         ucb->ts_idev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
 355
 356         /*
 357          * Enable ADC filter to prevent horrible jitter on Colibri.
 358          * This also further reduces jitter on boards where ADCSYNC
 359          * pin is connected.
 360          */
 361         fcsr = ucb1400_reg_read(ucb->ac97, UCB_FCSR);
 362         ucb1400_reg_write(ucb->ac97, UCB_FCSR, fcsr | UCB_FCSR_AVE);
 363
 364         ucb1400_adc_enable(ucb->ac97);
 365         x_res = ucb1400_ts_read_xres(ucb);
 366         y_res = ucb1400_ts_read_yres(ucb);
 367         ucb1400_adc_disable(ucb->ac97);
 368         dev_dbg(&pdev->dev, "x/y = %d/%d\n", x_res, y_res);
 369
 370         input_set_abs_params(ucb->ts_idev, ABS_X, 0, x_res, 0, 0);
 371         input_set_abs_params(ucb->ts_idev, ABS_Y, 0, y_res, 0, 0);
 372         input_set_abs_params(ucb->ts_idev, ABS_PRESSURE, 0, 0, 0, 0);
 373
 374         ucb1400_ts_stop(ucb);
 375
 376         error = request_threaded_irq(ucb->irq, NULL, ucb1400_irq,
 377                                      IRQF_TRIGGER_RISING | IRQF_ONESHOT,
 378                                      "UCB1400", ucb);
 379         if (error) {
 380                 dev_err(&pdev->dev,
 381                         "unable to grab irq%d: %d\n", ucb->irq, error);
 382                 goto err_free_devs;
 383         }
 384
 385         error = input_register_device(ucb->ts_idev);
 386         if (error)
 387                 goto err_free_irq;
 388
 389         return 0;
 390
 391 err_free_irq:
 392         free_irq(ucb->irq, ucb);
 393 err_free_devs:
 394         input_free_device(ucb->ts_idev);
 395 err:
 396         return error;
 397 }
 398
 399 static int ucb1400_ts_remove(struct platform_device *pdev)
 400 {
 401         struct ucb1400_ts *ucb = dev_get_platdata(&pdev->dev);
 402
 403         free_irq(ucb->irq, ucb);
 404         input_unregister_device(ucb->ts_idev);
 405
 406         return 0;
 407 }
 408
 409 static int __maybe_unused ucb1400_ts_suspend(struct device *dev)
 410 {
 411         struct ucb1400_ts *ucb = dev_get_platdata(dev);
 412         struct input_dev *idev = ucb->ts_idev;
 413
 414         mutex_lock(&idev->mutex);
 415
 416         if (idev->users)
 417                 ucb1400_ts_start(ucb);
 418
 419         mutex_unlock(&idev->mutex);
 420         return 0;
 421 }
 422
 423 static int __maybe_unused ucb1400_ts_resume(struct device *dev)
 424 {
 425         struct ucb1400_ts *ucb = dev_get_platdata(dev);
 426         struct input_dev *idev = ucb->ts_idev;
 427
 428         mutex_lock(&idev->mutex);
 429
 430         if (idev->users)
 431                 ucb1400_ts_stop(ucb);
 432
 433         mutex_unlock(&idev->mutex);
 434         return 0;
 435 }
 436
 437 static SIMPLE_DEV_PM_OPS(ucb1400_ts_pm_ops,
 438                          ucb1400_ts_suspend, ucb1400_ts_resume);
 439
 440 static struct platform_driver ucb1400_ts_driver = {
 441         .probe  = ucb1400_ts_probe,
 442         .remove = ucb1400_ts_remove,
 443         .driver = {
 444                 .name   = "ucb1400_ts",
 445                 .pm     = &ucb1400_ts_pm_ops,
 446         },
 447 };
 448 module_platform_driver(ucb1400_ts_driver);
 449
 450 module_param(adcsync, bool, 0444);
 451 MODULE_PARM_DESC(adcsync, "Synchronize touch readings with ADCSYNC pin.");
 452
 453 module_param(ts_delay, int, 0444);
 454 MODULE_PARM_DESC(ts_delay, "Delay between panel setup and"
 455                             " position read. Default = 55us.");
 456
 457 module_param(ts_delay_pressure, int, 0444);
 458 MODULE_PARM_DESC(ts_delay_pressure,
 459                 "delay between panel setup and pressure read."
 460                 "  Default = 0us.");
 461
 462 MODULE_DESCRIPTION("Philips UCB1400 touchscreen driver");
 463 MODULE_LICENSE("GPL");