drivers/input/touchscreen/ucb1400_ts.c

   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
  29 static bool adcsync;
  30 static int ts_delay = 55; /* us */
  31 static int ts_delay_pressure;   /* us */
  32
  33 /* Switch to interrupt mode. */
  34 static 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  */
  46 static 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  */
  64 static 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  */
  87 static 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  */
 108 static 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  */
 120 static 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
 128 static 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
 135 static 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
 142 static void ucb1400_ts_irq_disable(struct ucb1400_ts *ucb)
 143 {
 144         ucb1400_reg_write(ucb->ac97, UCB_IE_FAL, 0);
 145 }
 146
 147 static 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
 156 static 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
 163 static 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  */
 185 static 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
 224 static 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 */
 237 static 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
 249 static 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
 258 static 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  */
 273 static 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
 317 static 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
 388 err_free_irq:
 389         free_irq(ucb->irq, ucb);
 390 err_free_devs:
 391         input_free_device(ucb->ts_idev);
 392 err:
 393         return error;
 394 }
 395
 396 static 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
 406 static 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
 420 static 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
 434 static SIMPLE_DEV_PM_OPS(ucb1400_ts_pm_ops,
 435                          ucb1400_ts_suspend, ucb1400_ts_resume);
 436
 437 static 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 };
 445 module_platform_driver(ucb1400_ts_driver);
 446
 447 module_param(adcsync, bool, 0444);
 448 MODULE_PARM_DESC(adcsync, "Synchronize touch readings with ADCSYNC pin.");
 449
 450 module_param(ts_delay, int, 0444);
 451 MODULE_PARM_DESC(ts_delay, "Delay between panel setup and"
 452                             " position read. Default = 55us.");
 453
 454 module_param(ts_delay_pressure, int, 0444);
 455 MODULE_PARM_DESC(ts_delay_pressure,
 456                 "delay between panel setup and pressure read."
 457                 "  Default = 0us.");
 458
 459 MODULE_DESCRIPTION("Philips UCB1400 touchscreen driver");
 460 MODULE_LICENSE("GPL");