drivers/input/touchscreen/lpc32xx_ts.c

   1 /*
   2  * LPC32xx built-in touchscreen driver
   3  *
   4  * Copyright (C) 2010 NXP Semiconductors
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  */
  16
  17 #include <linux/platform_device.h>
  18 #include <linux/init.h>
  19 #include <linux/input.h>
  20 #include <linux/interrupt.h>
  21 #include <linux/module.h>
  22 #include <linux/clk.h>
  23 #include <linux/io.h>
  24 #include <linux/slab.h>
  25 #include <linux/of.h>
  26
  27 /*
  28  * Touchscreen controller register offsets
  29  */
  30 #define LPC32XX_TSC_STAT                        0x00
  31 #define LPC32XX_TSC_SEL                         0x04
  32 #define LPC32XX_TSC_CON                         0x08
  33 #define LPC32XX_TSC_FIFO                        0x0C
  34 #define LPC32XX_TSC_DTR                         0x10
  35 #define LPC32XX_TSC_RTR                         0x14
  36 #define LPC32XX_TSC_UTR                         0x18
  37 #define LPC32XX_TSC_TTR                         0x1C
  38 #define LPC32XX_TSC_DXP                         0x20
  39 #define LPC32XX_TSC_MIN_X                       0x24
  40 #define LPC32XX_TSC_MAX_X                       0x28
  41 #define LPC32XX_TSC_MIN_Y                       0x2C
  42 #define LPC32XX_TSC_MAX_Y                       0x30
  43 #define LPC32XX_TSC_AUX_UTR                     0x34
  44 #define LPC32XX_TSC_AUX_MIN                     0x38
  45 #define LPC32XX_TSC_AUX_MAX                     0x3C
  46
  47 #define LPC32XX_TSC_STAT_FIFO_OVRRN             (1 << 8)
  48 #define LPC32XX_TSC_STAT_FIFO_EMPTY             (1 << 7)
  49
  50 #define LPC32XX_TSC_SEL_DEFVAL                  0x0284
  51
  52 #define LPC32XX_TSC_ADCCON_IRQ_TO_FIFO_4        (0x1 << 11)
  53 #define LPC32XX_TSC_ADCCON_X_SAMPLE_SIZE(s)     ((10 - (s)) << 7)
  54 #define LPC32XX_TSC_ADCCON_Y_SAMPLE_SIZE(s)     ((10 - (s)) << 4)
  55 #define LPC32XX_TSC_ADCCON_POWER_UP             (1 << 2)
  56 #define LPC32XX_TSC_ADCCON_AUTO_EN              (1 << 0)
  57
  58 #define LPC32XX_TSC_FIFO_TS_P_LEVEL             (1 << 31)
  59 #define LPC32XX_TSC_FIFO_NORMALIZE_X_VAL(x)     (((x) & 0x03FF0000) >> 16)
  60 #define LPC32XX_TSC_FIFO_NORMALIZE_Y_VAL(y)     ((y) & 0x000003FF)
  61
  62 #define LPC32XX_TSC_ADCDAT_VALUE_MASK           0x000003FF
  63
  64 #define LPC32XX_TSC_MIN_XY_VAL                  0x0
  65 #define LPC32XX_TSC_MAX_XY_VAL                  0x3FF
  66
  67 #define MOD_NAME "ts-lpc32xx"
  68
  69 #define tsc_readl(dev, reg) \
  70         __raw_readl((dev)->tsc_base + (reg))
  71 #define tsc_writel(dev, reg, val) \
  72         __raw_writel((val), (dev)->tsc_base + (reg))
  73
  74 struct lpc32xx_tsc {
  75         struct input_dev *dev;
  76         void __iomem *tsc_base;
  77         int irq;
  78         struct clk *clk;
  79 };
  80
  81 static void lpc32xx_fifo_clear(struct lpc32xx_tsc *tsc)
  82 {
  83         while (!(tsc_readl(tsc, LPC32XX_TSC_STAT) &
  84                         LPC32XX_TSC_STAT_FIFO_EMPTY))
  85                 tsc_readl(tsc, LPC32XX_TSC_FIFO);
  86 }
  87
  88 static irqreturn_t lpc32xx_ts_interrupt(int irq, void *dev_id)
  89 {
  90         u32 tmp, rv[4], xs[4], ys[4];
  91         int idx;
  92         struct lpc32xx_tsc *tsc = dev_id;
  93         struct input_dev *input = tsc->dev;
  94
  95         tmp = tsc_readl(tsc, LPC32XX_TSC_STAT);
  96
  97         if (tmp & LPC32XX_TSC_STAT_FIFO_OVRRN) {
  98                 /* FIFO overflow - throw away samples */
  99                 lpc32xx_fifo_clear(tsc);
 100                 return IRQ_HANDLED;
 101         }
 102
 103         /*
 104          * Gather and normalize 4 samples. Pen-up events may have less
 105          * than 4 samples, but its ok to pop 4 and let the last sample
 106          * pen status check drop the samples.
 107          */
 108         idx = 0;
 109         while (idx < 4 &&
 110                !(tsc_readl(tsc, LPC32XX_TSC_STAT) &
 111                         LPC32XX_TSC_STAT_FIFO_EMPTY)) {
 112                 tmp = tsc_readl(tsc, LPC32XX_TSC_FIFO);
 113                 xs[idx] = LPC32XX_TSC_ADCDAT_VALUE_MASK -
 114                         LPC32XX_TSC_FIFO_NORMALIZE_X_VAL(tmp);
 115                 ys[idx] = LPC32XX_TSC_ADCDAT_VALUE_MASK -
 116                         LPC32XX_TSC_FIFO_NORMALIZE_Y_VAL(tmp);
 117                 rv[idx] = tmp;
 118                 idx++;
 119         }
 120
 121         /* Data is only valid if pen is still down in last sample */
 122         if (!(rv[3] & LPC32XX_TSC_FIFO_TS_P_LEVEL) && idx == 4) {
 123                 /* Use average of 2nd and 3rd sample for position */
 124                 input_report_abs(input, ABS_X, (xs[1] + xs[2]) / 2);
 125                 input_report_abs(input, ABS_Y, (ys[1] + ys[2]) / 2);
 126                 input_report_key(input, BTN_TOUCH, 1);
 127         } else {
 128                 input_report_key(input, BTN_TOUCH, 0);
 129         }
 130
 131         input_sync(input);
 132
 133         return IRQ_HANDLED;
 134 }
 135
 136 static void lpc32xx_stop_tsc(struct lpc32xx_tsc *tsc)
 137 {
 138         /* Disable auto mode */
 139         tsc_writel(tsc, LPC32XX_TSC_CON,
 140                    tsc_readl(tsc, LPC32XX_TSC_CON) &
 141                              ~LPC32XX_TSC_ADCCON_AUTO_EN);
 142
 143         clk_disable(tsc->clk);
 144 }
 145
 146 static void lpc32xx_setup_tsc(struct lpc32xx_tsc *tsc)
 147 {
 148         u32 tmp;
 149
 150         clk_enable(tsc->clk);
 151
 152         tmp = tsc_readl(tsc, LPC32XX_TSC_CON) & ~LPC32XX_TSC_ADCCON_POWER_UP;
 153
 154         /* Set the TSC FIFO depth to 4 samples @ 10-bits per sample (max) */
 155         tmp = LPC32XX_TSC_ADCCON_IRQ_TO_FIFO_4 |
 156               LPC32XX_TSC_ADCCON_X_SAMPLE_SIZE(10) |
 157               LPC32XX_TSC_ADCCON_Y_SAMPLE_SIZE(10);
 158         tsc_writel(tsc, LPC32XX_TSC_CON, tmp);
 159
 160         /* These values are all preset */
 161         tsc_writel(tsc, LPC32XX_TSC_SEL, LPC32XX_TSC_SEL_DEFVAL);
 162         tsc_writel(tsc, LPC32XX_TSC_MIN_X, LPC32XX_TSC_MIN_XY_VAL);
 163         tsc_writel(tsc, LPC32XX_TSC_MAX_X, LPC32XX_TSC_MAX_XY_VAL);
 164         tsc_writel(tsc, LPC32XX_TSC_MIN_Y, LPC32XX_TSC_MIN_XY_VAL);
 165         tsc_writel(tsc, LPC32XX_TSC_MAX_Y, LPC32XX_TSC_MAX_XY_VAL);
 166
 167         /* Aux support is not used */
 168         tsc_writel(tsc, LPC32XX_TSC_AUX_UTR, 0);
 169         tsc_writel(tsc, LPC32XX_TSC_AUX_MIN, 0);
 170         tsc_writel(tsc, LPC32XX_TSC_AUX_MAX, 0);
 171
 172         /*
 173          * Set sample rate to about 240Hz per X/Y pair. A single measurement
 174          * consists of 4 pairs which gives about a 60Hz sample rate based on
 175          * a stable 32768Hz clock source. Values are in clocks.
 176          * Rate is (32768 / (RTR + XCONV + RTR + YCONV + DXP + TTR + UTR) / 4
 177          */
 178         tsc_writel(tsc, LPC32XX_TSC_RTR, 0x2);
 179         tsc_writel(tsc, LPC32XX_TSC_DTR, 0x2);
 180         tsc_writel(tsc, LPC32XX_TSC_TTR, 0x10);
 181         tsc_writel(tsc, LPC32XX_TSC_DXP, 0x4);
 182         tsc_writel(tsc, LPC32XX_TSC_UTR, 88);
 183
 184         lpc32xx_fifo_clear(tsc);
 185
 186         /* Enable automatic ts event capture */
 187         tsc_writel(tsc, LPC32XX_TSC_CON, tmp | LPC32XX_TSC_ADCCON_AUTO_EN);
 188 }
 189
 190 static int lpc32xx_ts_open(struct input_dev *dev)
 191 {
 192         struct lpc32xx_tsc *tsc = input_get_drvdata(dev);
 193
 194         lpc32xx_setup_tsc(tsc);
 195
 196         return 0;
 197 }
 198
 199 static void lpc32xx_ts_close(struct input_dev *dev)
 200 {
 201         struct lpc32xx_tsc *tsc = input_get_drvdata(dev);
 202
 203         lpc32xx_stop_tsc(tsc);
 204 }
 205
 206 static int lpc32xx_ts_probe(struct platform_device *pdev)
 207 {
 208         struct lpc32xx_tsc *tsc;
 209         struct input_dev *input;
 210         struct resource *res;
 211         resource_size_t size;
 212         int irq;
 213         int error;
 214
 215         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 216         if (!res) {
 217                 dev_err(&pdev->dev, "Can't get memory resource\n");
 218                 return -ENOENT;
 219         }
 220
 221         irq = platform_get_irq(pdev, 0);
 222         if (irq < 0) {
 223                 dev_err(&pdev->dev, "Can't get interrupt resource\n");
 224                 return irq;
 225         }
 226
 227         tsc = kzalloc(sizeof(*tsc), GFP_KERNEL);
 228         input = input_allocate_device();
 229         if (!tsc || !input) {
 230                 dev_err(&pdev->dev, "failed allocating memory\n");
 231                 error = -ENOMEM;
 232                 goto err_free_mem;
 233         }
 234
 235         tsc->dev = input;
 236         tsc->irq = irq;
 237
 238         size = resource_size(res);
 239
 240         if (!request_mem_region(res->start, size, pdev->name)) {
 241                 dev_err(&pdev->dev, "TSC registers are not free\n");
 242                 error = -EBUSY;
 243                 goto err_free_mem;
 244         }
 245
 246         tsc->tsc_base = ioremap(res->start, size);
 247         if (!tsc->tsc_base) {
 248                 dev_err(&pdev->dev, "Can't map memory\n");
 249                 error = -ENOMEM;
 250                 goto err_release_mem;
 251         }
 252
 253         tsc->clk = clk_get(&pdev->dev, NULL);
 254         if (IS_ERR(tsc->clk)) {
 255                 dev_err(&pdev->dev, "failed getting clock\n");
 256                 error = PTR_ERR(tsc->clk);
 257                 goto err_unmap;
 258         }
 259
 260         input->name = MOD_NAME;
 261         input->phys = "lpc32xx/input0";
 262         input->id.bustype = BUS_HOST;
 263         input->id.vendor = 0x0001;
 264         input->id.product = 0x0002;
 265         input->id.version = 0x0100;
 266         input->dev.parent = &pdev->dev;
 267         input->open = lpc32xx_ts_open;
 268         input->close = lpc32xx_ts_close;
 269
 270         input->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
 271         input->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
 272         input_set_abs_params(input, ABS_X, LPC32XX_TSC_MIN_XY_VAL,
 273                              LPC32XX_TSC_MAX_XY_VAL, 0, 0);
 274         input_set_abs_params(input, ABS_Y, LPC32XX_TSC_MIN_XY_VAL,
 275                              LPC32XX_TSC_MAX_XY_VAL, 0, 0);
 276
 277         input_set_drvdata(input, tsc);
 278
 279         error = request_irq(tsc->irq, lpc32xx_ts_interrupt,
 280                             0, pdev->name, tsc);
 281         if (error) {
 282                 dev_err(&pdev->dev, "failed requesting interrupt\n");
 283                 goto err_put_clock;
 284         }
 285
 286         error = input_register_device(input);
 287         if (error) {
 288                 dev_err(&pdev->dev, "failed registering input device\n");
 289                 goto err_free_irq;
 290         }
 291
 292         platform_set_drvdata(pdev, tsc);
 293         device_init_wakeup(&pdev->dev, 1);
 294
 295         return 0;
 296
 297 err_free_irq:
 298         free_irq(tsc->irq, tsc);
 299 err_put_clock:
 300         clk_put(tsc->clk);
 301 err_unmap:
 302         iounmap(tsc->tsc_base);
 303 err_release_mem:
 304         release_mem_region(res->start, size);
 305 err_free_mem:
 306         input_free_device(input);
 307         kfree(tsc);
 308
 309         return error;
 310 }
 311
 312 static int lpc32xx_ts_remove(struct platform_device *pdev)
 313 {
 314         struct lpc32xx_tsc *tsc = platform_get_drvdata(pdev);
 315         struct resource *res;
 316
 317         device_init_wakeup(&pdev->dev, 0);
 318         free_irq(tsc->irq, tsc);
 319
 320         input_unregister_device(tsc->dev);
 321
 322         clk_put(tsc->clk);
 323
 324         iounmap(tsc->tsc_base);
 325         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 326         release_mem_region(res->start, resource_size(res));
 327
 328         kfree(tsc);
 329
 330         return 0;
 331 }
 332
 333 #ifdef CONFIG_PM
 334 static int lpc32xx_ts_suspend(struct device *dev)
 335 {
 336         struct lpc32xx_tsc *tsc = dev_get_drvdata(dev);
 337         struct input_dev *input = tsc->dev;
 338
 339         /*
 340          * Suspend and resume can be called when the device hasn't been
 341          * enabled. If there are no users that have the device open, then
 342          * avoid calling the TSC stop and start functions as the TSC
 343          * isn't yet clocked.
 344          */
 345         mutex_lock(&input->mutex);
 346
 347         if (input->users) {
 348                 if (device_may_wakeup(dev))
 349                         enable_irq_wake(tsc->irq);
 350                 else
 351                         lpc32xx_stop_tsc(tsc);
 352         }
 353
 354         mutex_unlock(&input->mutex);
 355
 356         return 0;
 357 }
 358
 359 static int lpc32xx_ts_resume(struct device *dev)
 360 {
 361         struct lpc32xx_tsc *tsc = dev_get_drvdata(dev);
 362         struct input_dev *input = tsc->dev;
 363
 364         mutex_lock(&input->mutex);
 365
 366         if (input->users) {
 367                 if (device_may_wakeup(dev))
 368                         disable_irq_wake(tsc->irq);
 369                 else
 370                         lpc32xx_setup_tsc(tsc);
 371         }
 372
 373         mutex_unlock(&input->mutex);
 374
 375         return 0;
 376 }
 377
 378 static const struct dev_pm_ops lpc32xx_ts_pm_ops = {
 379         .suspend        = lpc32xx_ts_suspend,
 380         .resume         = lpc32xx_ts_resume,
 381 };
 382 #define LPC32XX_TS_PM_OPS (&lpc32xx_ts_pm_ops)
 383 #else
 384 #define LPC32XX_TS_PM_OPS NULL
 385 #endif
 386
 387 #ifdef CONFIG_OF
 388 static struct of_device_id lpc32xx_tsc_of_match[] = {
 389         { .compatible = "nxp,lpc3220-tsc", },
 390         { },
 391 };
 392 MODULE_DEVICE_TABLE(of, lpc32xx_tsc_of_match);
 393 #endif
 394
 395 static struct platform_driver lpc32xx_ts_driver = {
 396         .probe          = lpc32xx_ts_probe,
 397         .remove         = lpc32xx_ts_remove,
 398         .driver         = {
 399                 .name   = MOD_NAME,
 400                 .owner  = THIS_MODULE,
 401                 .pm     = LPC32XX_TS_PM_OPS,
 402                 .of_match_table = of_match_ptr(lpc32xx_tsc_of_match),
 403         },
 404 };
 405 module_platform_driver(lpc32xx_ts_driver);
 406
 407 MODULE_AUTHOR("Kevin Wells <kevin.wells@nxp.com");
 408 MODULE_DESCRIPTION("LPC32XX TSC Driver");
 409 MODULE_LICENSE("GPL");
 410 MODULE_ALIAS("platform:lpc32xx_ts");