LXR linux/drivers/input/touchscreen/ucb1400

   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 *  Philips UCB1400 touchscreen driver
   4 *
   5 *  Author:     Nicolas Pitre
   6 *  Created:    September 25, 2006
   7 *  Copyright:  MontaVista Software, Inc.
   8 *
   9 * Spliting done by: Marek Vasut <marek.vasut@gmail.com>
  10 * If something doesn't work and it worked before spliting, e-mail me,
  11 * dont bother Nicolas please ;-)
  12 *
  13 * This code is heavily based on ucb1x00-*.c copyrighted by Russell King
  14 * covering the UCB1100, UCB1200 and UCB1300..  Support for the UCB1400 has
  15 * been made separate from ucb1x00-core/ucb1x00-ts on Russell's request.
  16 */
  17
  18#include <linux/module.h>
  19#include <linux/delay.h>
  20#include <linux/sched.h>
  21#include <linux/wait.h>
  22#include <linux/input.h>
  23#include <linux/device.h>
  24#include <linux/interrupt.h>
  25#include <linux/ucb1400.h>
  26
  27#define UCB1400_TS_POLL_PERIOD  10 /* ms */
  28
  29static bool adcsync;
  30static int ts_delay = 55; /* us */
  31static int ts_delay_pressure;   /* us */
  32
  33/* Switch to interrupt mode. */
  34static void ucb1400_ts_mode_int(struct ucb1400_ts *ucb)
  35{
  36        ucb1400_reg_write(ucb->ac97, UCB_TS_CR,
  37                        UCB_TS_CR_TSMX_POW | UCB_TS_CR_TSPX_POW |
  38                        UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_GND |
  39                        UCB_TS_CR_MODE_INT);
  40}
  41
  42/*
  43 * Switch to pressure mode, and read pressure.  We don't need to wait
  44 * here, since both plates are being driven.
  45 */
  46static unsigned int ucb1400_ts_read_pressure(struct ucb1400_ts *ucb)
  47{
  48        ucb1400_reg_write(ucb->ac97, UCB_TS_CR,
  49                        UCB_TS_CR_TSMX_POW | UCB_TS_CR_TSPX_POW |
  50                        UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_GND |
  51                        UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA);
  52
  53        udelay(ts_delay_pressure);
  54
  55        return ucb1400_adc_read(ucb->ac97, UCB_ADC_INP_TSPY, adcsync);
  56}
  57
  58/*
  59 * Switch to X position mode and measure Y plate.  We switch the plate
  60 * configuration in pressure mode, then switch to position mode.  This
  61 * gives a faster response time.  Even so, we need to wait about 55us
  62 * for things to stabilise.
  63 */
  64static unsigned int ucb1400_ts_read_xpos(struct ucb1400_ts *ucb)
  65{
  66        ucb1400_reg_write(ucb->ac97, UCB_TS_CR,
  67                        UCB_TS_CR_TSMX_GND | UCB_TS_CR_TSPX_POW |
  68                        UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA);
  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_POS | UCB_TS_CR_BIAS_ENA);
  75
  76        udelay(ts_delay);
  77
  78        return ucb1400_adc_read(ucb->ac97, UCB_ADC_INP_TSPY, adcsync);
  79}
  80
  81/*
  82 * Switch to Y position mode and measure X plate.  We switch the plate
  83 * configuration in pressure mode, then switch to position mode.  This
  84 * gives a faster response time.  Even so, we need to wait about 55us
  85 * for things to stabilise.
  86 */
  87static int ucb1400_ts_read_ypos(struct ucb1400_ts *ucb)
  88{
  89        ucb1400_reg_write(ucb->ac97, UCB_TS_CR,
  90                        UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_POW |
  91                        UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA);
  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_POS | UCB_TS_CR_BIAS_ENA);
  98
  99        udelay(ts_delay);
 100
 101        return ucb1400_adc_read(ucb->ac97, UCB_ADC_INP_TSPX, adcsync);
 102}
 103
 104/*
 105 * Switch to X plate resistance mode.  Set MX to ground, PX to
 106 * supply.  Measure current.
 107 */
 108static unsigned int ucb1400_ts_read_xres(struct ucb1400_ts *ucb)
 109{
 110        ucb1400_reg_write(ucb->ac97, UCB_TS_CR,
 111                        UCB_TS_CR_TSMX_GND | UCB_TS_CR_TSPX_POW |
 112                        UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA);
 113        return ucb1400_adc_read(ucb->ac97, 0, adcsync);
 114}
 115
 116/*
 117 * Switch to Y plate resistance mode.  Set MY to ground, PY to
 118 * supply.  Measure current.
 119 */
 120static unsigned int ucb1400_ts_read_yres(struct ucb1400_ts *ucb)
 121{
 122        ucb1400_reg_write(ucb->ac97, UCB_TS_CR,
 123                        UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_POW |
 124                        UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA);
 125        return ucb1400_adc_read(ucb->ac97, 0, adcsync);
 126}
 127
 128static int ucb1400_ts_pen_up(struct ucb1400_ts *ucb)
 129{
 130        unsigned short val = ucb1400_reg_read(ucb->ac97, UCB_TS_CR);
 131
 132        return val & (UCB_TS_CR_TSPX_LOW | UCB_TS_CR_TSMX_LOW);
 133}
 134
 135static void ucb1400_ts_irq_enable(struct ucb1400_ts *ucb)
 136{
 137        ucb1400_reg_write(ucb->ac97, UCB_IE_CLEAR, UCB_IE_TSPX);
 138        ucb1400_reg_write(ucb->ac97, UCB_IE_CLEAR, 0);
 139        ucb1400_reg_write(ucb->ac97, UCB_IE_FAL, UCB_IE_TSPX);
 140}
 141
 142static void ucb1400_ts_irq_disable(struct ucb1400_ts *ucb)
 143{
 144        ucb1400_reg_write(ucb->ac97, UCB_IE_FAL, 0);
 145}
 146
 147static void ucb1400_ts_report_event(struct input_dev *idev, u16 pressure, u16 x, u16 y)
 148{
 149        input_report_abs(idev, ABS_X, x);
 150        input_report_abs(idev, ABS_Y, y);
 151        input_report_abs(idev, ABS_PRESSURE, pressure);
 152        input_report_key(idev, BTN_TOUCH, 1);
 153        input_sync(idev);
 154}
 155
 156static void ucb1400_ts_event_release(struct input_dev *idev)
 157{
 158        input_report_abs(idev, ABS_PRESSURE, 0);
 159        input_report_key(idev, BTN_TOUCH, 0);
 160        input_sync(idev);
 161}
 162
 163static void ucb1400_clear_pending_irq(struct ucb1400_ts *ucb)
 164{
 165        unsigned int isr;
 166
 167        isr = ucb1400_reg_read(ucb->ac97, UCB_IE_STATUS);
 168        ucb1400_reg_write(ucb->ac97, UCB_IE_CLEAR, isr);
 169        ucb1400_reg_write(ucb->ac97, UCB_IE_CLEAR, 0);
 170
 171        if (isr & UCB_IE_TSPX)
 172                ucb1400_ts_irq_disable(ucb);
 173        else
 174                dev_dbg(&ucb->ts_idev->dev,
 175                        "ucb1400: unexpected IE_STATUS = %#x\n", isr);
 176}
 177
 178/*
 179 * A restriction with interrupts exists when using the ucb1400, as
 180 * the codec read/write routines may sleep while waiting for codec
 181 * access completion and uses semaphores for access control to the
 182 * AC97 bus. Therefore the driver is forced to use threaded interrupt
 183 * handler.
 184 */
 185static irqreturn_t ucb1400_irq(int irqnr, void *devid)
 186{
 187        struct ucb1400_ts *ucb = devid;
 188        unsigned int x, y, p;
 189        bool penup;
 190
 191        if (unlikely(irqnr != ucb->irq))
 192                return IRQ_NONE;
 193
 194        ucb1400_clear_pending_irq(ucb);
 195
 196        /* Start with a small delay before checking pendown state */
 197        msleep(UCB1400_TS_POLL_PERIOD);
 198
 199        while (!ucb->stopped && !(penup = ucb1400_ts_pen_up(ucb))) {
 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                ucb1400_ts_report_event(ucb->ts_idev, p, x, y);
 208
 209                wait_event_timeout(ucb->ts_wait, ucb->stopped,
 210                                   msecs_to_jiffies(UCB1400_TS_POLL_PERIOD));
 211        }
 212
 213        ucb1400_ts_event_release(ucb->ts_idev);
 214
 215        if (!ucb->stopped) {
 216                /* Switch back to interrupt mode. */
 217                ucb1400_ts_mode_int(ucb);
 218                ucb1400_ts_irq_enable(ucb);
 219        }
 220
 221        return IRQ_HANDLED;
 222}
 223
 224static void ucb1400_ts_stop(struct ucb1400_ts *ucb)
 225{
 226        /* Signal IRQ thread to stop polling and disable the handler. */
 227        ucb->stopped = true;
 228        mb();
 229        wake_up(&ucb->ts_wait);
 230        disable_irq(ucb->irq);
 231
 232        ucb1400_ts_irq_disable(ucb);
 233        ucb1400_reg_write(ucb->ac97, UCB_TS_CR, 0);
 234}
 235
 236/* Must be called with ts->lock held */
 237static void ucb1400_ts_start(struct ucb1400_ts *ucb)
 238{
 239        /* Tell IRQ thread that it may poll the device. */
 240        ucb->stopped = false;
 241        mb();
 242
 243        ucb1400_ts_mode_int(ucb);
 244        ucb1400_ts_irq_enable(ucb);
 245
 246        enable_irq(ucb->irq);
 247}
 248
 249static int ucb1400_ts_open(struct input_dev *idev)
 250{
 251        struct ucb1400_ts *ucb = input_get_drvdata(idev);
 252
 253        ucb1400_ts_start(ucb);
 254
 255        return 0;
 256}
 257
 258static void ucb1400_ts_close(struct input_dev *idev)
 259{
 260        struct ucb1400_ts *ucb = input_get_drvdata(idev);
 261
 262        ucb1400_ts_stop(ucb);
 263}
 264
 265#ifndef NO_IRQ
 266#define NO_IRQ  0
 267#endif
 268
 269/*
 270 * Try to probe our interrupt, rather than relying on lots of
 271 * hard-coded machine dependencies.
 272 */
 273static int ucb1400_ts_detect_irq(struct ucb1400_ts *ucb,
 274                                           struct platform_device *pdev)
 275{
 276        unsigned long mask, timeout;
 277
 278        mask = probe_irq_on();
 279
 280        /* Enable the ADC interrupt. */
 281        ucb1400_reg_write(ucb->ac97, UCB_IE_RIS, UCB_IE_ADC);
 282        ucb1400_reg_write(ucb->ac97, UCB_IE_FAL, UCB_IE_ADC);
 283        ucb1400_reg_write(ucb->ac97, UCB_IE_CLEAR, 0xffff);
 284        ucb1400_reg_write(ucb->ac97, UCB_IE_CLEAR, 0);
 285
 286        /* Cause an ADC interrupt. */
 287        ucb1400_reg_write(ucb->ac97, UCB_ADC_CR, UCB_ADC_ENA);
 288        ucb1400_reg_write(ucb->ac97, UCB_ADC_CR, UCB_ADC_ENA | UCB_ADC_START);
 289
 290        /* Wait for the conversion to complete. */
 291        timeout = jiffies + HZ/2;
 292        while (!(ucb1400_reg_read(ucb->ac97, UCB_ADC_DATA) &
 293                                                UCB_ADC_DAT_VALID)) {
 294                cpu_relax();
 295                if (time_after(jiffies, timeout)) {
 296                        dev_err(&pdev->dev, "timed out in IRQ probe\n");
 297                        probe_irq_off(mask);
 298                        return -ENODEV;
 299                }
 300        }
 301        ucb1400_reg_write(ucb->ac97, UCB_ADC_CR, 0);
 302
 303        /* Disable and clear interrupt. */
 304        ucb1400_reg_write(ucb->ac97, UCB_IE_RIS, 0);
 305        ucb1400_reg_write(ucb->ac97, UCB_IE_FAL, 0);
 306        ucb1400_reg_write(ucb->ac97, UCB_IE_CLEAR, 0xffff);
 307        ucb1400_reg_write(ucb->ac97, UCB_IE_CLEAR, 0);
 308
 309        /* Read triggered interrupt. */
 310        ucb->irq = probe_irq_off(mask);
 311        if (ucb->irq < 0 || ucb->irq == NO_IRQ)
 312                return -ENODEV;
 313
 314        return 0;
 315}
 316
 317static int ucb1400_ts_probe(struct platform_device *pdev)
 318{
 319        struct ucb1400_ts *ucb = dev_get_platdata(&pdev->dev);
 320        int error, x_res, y_res;
 321        u16 fcsr;
 322
 323        ucb->ts_idev = input_allocate_device();
 324        if (!ucb->ts_idev) {
 325                error = -ENOMEM;
 326                goto err;
 327        }
 328
 329        /* Only in case the IRQ line wasn't supplied, try detecting it */
 330        if (ucb->irq < 0) {
 331                error = ucb1400_ts_detect_irq(ucb, pdev);
 332                if (error) {
 333                        dev_err(&pdev->dev, "IRQ probe failed\n");
 334                        goto err_free_devs;
 335                }
 336        }
 337        dev_dbg(&pdev->dev, "found IRQ %d\n", ucb->irq);
 338
 339        init_waitqueue_head(&ucb->ts_wait);
 340
 341        input_set_drvdata(ucb->ts_idev, ucb);
 342
 343        ucb->ts_idev->dev.parent        = &pdev->dev;
 344        ucb->ts_idev->name              = "UCB1400 touchscreen interface";
 345        ucb->ts_idev->id.vendor         = ucb1400_reg_read(ucb->ac97,
 346                                                AC97_VENDOR_ID1);
 347        ucb->ts_idev->id.product        = ucb->id;
 348        ucb->ts_idev->open              = ucb1400_ts_open;
 349        ucb->ts_idev->close             = ucb1400_ts_close;
 350        ucb->ts_idev->evbit[0]          = BIT_MASK(EV_ABS) | BIT_MASK(EV_KEY);
 351        ucb->ts_idev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
 352
 353        /*
 354         * Enable ADC filter to prevent horrible jitter on Colibri.
 355         * This also further reduces jitter on boards where ADCSYNC
 356         * pin is connected.
 357         */
 358        fcsr = ucb1400_reg_read(ucb->ac97, UCB_FCSR);
 359        ucb1400_reg_write(ucb->ac97, UCB_FCSR, fcsr | UCB_FCSR_AVE);
 360
 361        ucb1400_adc_enable(ucb->ac97);
 362        x_res = ucb1400_ts_read_xres(ucb);
 363        y_res = ucb1400_ts_read_yres(ucb);
 364        ucb1400_adc_disable(ucb->ac97);
 365        dev_dbg(&pdev->dev, "x/y = %d/%d\n", x_res, y_res);
 366
 367        input_set_abs_params(ucb->ts_idev, ABS_X, 0, x_res, 0, 0);
 368        input_set_abs_params(ucb->ts_idev, ABS_Y, 0, y_res, 0, 0);
 369        input_set_abs_params(ucb->ts_idev, ABS_PRESSURE, 0, 0, 0, 0);
 370
 371        ucb1400_ts_stop(ucb);
 372
 373        error = request_threaded_irq(ucb->irq, NULL, ucb1400_irq,
 374                                     IRQF_TRIGGER_RISING | IRQF_ONESHOT,
 375                                     "UCB1400", ucb);
 376        if (error) {
 377                dev_err(&pdev->dev,
 378                        "unable to grab irq%d: %d\n", ucb->irq, error);
 379                goto err_free_devs;
 380        }
 381
 382        error = input_register_device(ucb->ts_idev);
 383        if (error)
 384                goto err_free_irq;
 385
 386        return 0;
 387
 388err_free_irq:
 389        free_irq(ucb->irq, ucb);
 390err_free_devs:
 391        input_free_device(ucb->ts_idev);
 392err:
 393        return error;
 394}
 395
 396static int ucb1400_ts_remove(struct platform_device *pdev)
 397{
 398        struct ucb1400_ts *ucb = dev_get_platdata(&pdev->dev);
 399
 400        free_irq(ucb->irq, ucb);
 401        input_unregister_device(ucb->ts_idev);
 402
 403        return 0;
 404}
 405
 406static int __maybe_unused ucb1400_ts_suspend(struct device *dev)
 407{
 408        struct ucb1400_ts *ucb = dev_get_platdata(dev);
 409        struct input_dev *idev = ucb->ts_idev;
 410
 411        mutex_lock(&idev->mutex);
 412
 413        if (idev->users)
 414                ucb1400_ts_stop(ucb);
 415
 416        mutex_unlock(&idev->mutex);
 417        return 0;
 418}
 419
 420static int __maybe_unused ucb1400_ts_resume(struct device *dev)
 421{
 422        struct ucb1400_ts *ucb = dev_get_platdata(dev);
 423        struct input_dev *idev = ucb->ts_idev;
 424
 425        mutex_lock(&idev->mutex);
 426
 427        if (idev->users)
 428                ucb1400_ts_start(ucb);
 429
 430        mutex_unlock(&idev->mutex);
 431        return 0;
 432}
 433
 434static SIMPLE_DEV_PM_OPS(ucb1400_ts_pm_ops,
 435                         ucb1400_ts_suspend, ucb1400_ts_resume);
 436
 437static struct platform_driver ucb1400_ts_driver = {
 438        .probe  = ucb1400_ts_probe,
 439        .remove = ucb1400_ts_remove,
 440        .driver = {
 441                .name   = "ucb1400_ts",
 442                .pm     = &ucb1400_ts_pm_ops,
 443        },
 444};
 445module_platform_driver(ucb1400_ts_driver);
 446
 447module_param(adcsync, bool, 0444);
 448MODULE_PARM_DESC(adcsync, "Synchronize touch readings with ADCSYNC pin.");
 449
 450module_param(ts_delay, int, 0444);
 451MODULE_PARM_DESC(ts_delay, "Delay between panel setup and"
 452                            " position read. Default = 55us.");
 453
 454module_param(ts_delay_pressure, int, 0444);
 455MODULE_PARM_DESC(ts_delay_pressure,
 456                "delay between panel setup and pressure read."
 457                "  Default = 0us.");
 458
 459MODULE_DESCRIPTION("Philips UCB1400 touchscreen driver");
 460MODULE_LICENSE("GPL");
 461