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