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/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
  33static int adcsync;
  34static int ts_delay = 55; /* us */
  35static int ts_delay_pressure;   /* us */
  36
  37/* Switch to interrupt mode. */
  38static 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 */
  50static 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 */
  66static 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 */
  89static 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 */
 110static 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 */
 122static 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
 130static 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
 137static 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
 144static inline void ucb1400_ts_irq_disable(struct snd_ac97 *ac97)
 145{
 146        ucb1400_reg_write(ac97, UCB_IE_FAL, 0);
 147}
 148
 149static 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
 158static 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
 165static 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
 180static 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 */
 254static 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
 267static 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
 283static 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 */
 302static 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
 345static 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
 413err_free_irq:
 414        free_irq(ucb->irq, ucb);
 415err_free_devs:
 416        input_free_device(ucb->ts_idev);
 417err:
 418        return error;
 419
 420}
 421
 422static 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
 432static 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
 451static 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
 460static int __init ucb1400_ts_init(void)
 461{
 462        return platform_driver_register(&ucb1400_ts_driver);
 463}
 464
 465static void __exit ucb1400_ts_exit(void)
 466{
 467        platform_driver_unregister(&ucb1400_ts_driver);
 468}
 469
 470module_param(adcsync, bool, 0444);
 471MODULE_PARM_DESC(adcsync, "Synchronize touch readings with ADCSYNC pin.");
 472
 473module_param(ts_delay, int, 0444);
 474MODULE_PARM_DESC(ts_delay, "Delay between panel setup and"
 475                            " position read. Default = 55us.");
 476
 477module_param(ts_delay_pressure, int, 0444);
 478MODULE_PARM_DESC(ts_delay_pressure,
 479                "delay between panel setup and pressure read."
 480                "  Default = 0us.");
 481
 482module_init(ucb1400_ts_init);
 483module_exit(ucb1400_ts_exit);
 484
 485MODULE_DESCRIPTION("Philips UCB1400 touchscreen driver");
 486MODULE_LICENSE("GPL");
 487