LXR linux/drivers/input/touchscreen/ucb1400

   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
  32static bool adcsync;
  33static int ts_delay = 55; /* us */
  34static int ts_delay_pressure;   /* us */
  35
  36/* Switch to interrupt mode. */
  37static 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 */
  49static 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 */
  67static 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 */
  90static 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 */
 111static 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 */
 123static 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
 131static 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
 138static 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
 145static void ucb1400_ts_irq_disable(struct ucb1400_ts *ucb)
 146{
 147        ucb1400_reg_write(ucb->ac97, UCB_IE_FAL, 0);
 148}
 149
 150static 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
 159static 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
 166static 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 */
 188static 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
 227static 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 */
 240static 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
 252static 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
 261static 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 */
 276static 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
 320static 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
 391err_free_irq:
 392        free_irq(ucb->irq, ucb);
 393err_free_devs:
 394        input_free_device(ucb->ts_idev);
 395err:
 396        return error;
 397}
 398
 399static 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
 409static 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
 423static 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
 437static SIMPLE_DEV_PM_OPS(ucb1400_ts_pm_ops,
 438                         ucb1400_ts_suspend, ucb1400_ts_resume);
 439
 440static 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};
 448module_platform_driver(ucb1400_ts_driver);
 449
 450module_param(adcsync, bool, 0444);
 451MODULE_PARM_DESC(adcsync, "Synchronize touch readings with ADCSYNC pin.");
 452
 453module_param(ts_delay, int, 0444);
 454MODULE_PARM_DESC(ts_delay, "Delay between panel setup and"
 455                            " position read. Default = 55us.");
 456
 457module_param(ts_delay_pressure, int, 0444);
 458MODULE_PARM_DESC(ts_delay_pressure,
 459                "delay between panel setup and pressure read."
 460                "  Default = 0us.");
 461
 462MODULE_DESCRIPTION("Philips UCB1400 touchscreen driver");
 463MODULE_LICENSE("GPL");
 464