drivers/input/touchscreen/da9034-ts.c

   1 /*
   2  * Touchscreen driver for Dialog Semiconductor DA9034
   3  *
   4  * Copyright (C) 2006-2008 Marvell International Ltd.
   5  *      Fengwei Yin <fengwei.yin@marvell.com>
   6  *      Eric Miao <eric.miao@marvell.com>
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License version 2 as
  10  * published by the Free Software Foundation.
  11  */
  12
  13 #include <linux/module.h>
  14 #include <linux/kernel.h>
  15 #include <linux/init.h>
  16 #include <linux/delay.h>
  17 #include <linux/platform_device.h>
  18 #include <linux/input.h>
  19 #include <linux/workqueue.h>
  20 #include <linux/mfd/da903x.h>
  21
  22 #define DA9034_MANUAL_CTRL      0x50
  23 #define DA9034_LDO_ADC_EN       (1 << 4)
  24
  25 #define DA9034_AUTO_CTRL1       0x51
  26
  27 #define DA9034_AUTO_CTRL2       0x52
  28 #define DA9034_AUTO_TSI_EN      (1 << 3)
  29 #define DA9034_PEN_DETECT       (1 << 4)
  30
  31 #define DA9034_TSI_CTRL1        0x53
  32 #define DA9034_TSI_CTRL2        0x54
  33 #define DA9034_TSI_X_MSB        0x6c
  34 #define DA9034_TSI_Y_MSB        0x6d
  35 #define DA9034_TSI_XY_LSB       0x6e
  36
  37 enum {
  38         STATE_IDLE,     /* wait for pendown */
  39         STATE_BUSY,     /* TSI busy sampling */
  40         STATE_STOP,     /* sample available */
  41         STATE_WAIT,     /* Wait to start next sample */
  42 };
  43
  44 enum {
  45         EVENT_PEN_DOWN,
  46         EVENT_PEN_UP,
  47         EVENT_TSI_READY,
  48         EVENT_TIMEDOUT,
  49 };
  50
  51 struct da9034_touch {
  52         struct device           *da9034_dev;
  53         struct input_dev        *input_dev;
  54
  55         struct delayed_work     tsi_work;
  56         struct notifier_block   notifier;
  57
  58         int     state;
  59
  60         int     interval_ms;
  61         int     x_inverted;
  62         int     y_inverted;
  63
  64         int     last_x;
  65         int     last_y;
  66 };
  67
  68 static inline int is_pen_down(struct da9034_touch *touch)
  69 {
  70         return da903x_query_status(touch->da9034_dev, DA9034_STATUS_PEN_DOWN);
  71 }
  72
  73 static inline int detect_pen_down(struct da9034_touch *touch, int on)
  74 {
  75         if (on)
  76                 return da903x_set_bits(touch->da9034_dev,
  77                                 DA9034_AUTO_CTRL2, DA9034_PEN_DETECT);
  78         else
  79                 return da903x_clr_bits(touch->da9034_dev,
  80                                 DA9034_AUTO_CTRL2, DA9034_PEN_DETECT);
  81 }
  82
  83 static int read_tsi(struct da9034_touch *touch)
  84 {
  85         uint8_t _x, _y, _v;
  86         int ret;
  87
  88         ret = da903x_read(touch->da9034_dev, DA9034_TSI_X_MSB, &_x);
  89         if (ret)
  90                 return ret;
  91
  92         ret = da903x_read(touch->da9034_dev, DA9034_TSI_Y_MSB, &_y);
  93         if (ret)
  94                 return ret;
  95
  96         ret = da903x_read(touch->da9034_dev, DA9034_TSI_XY_LSB, &_v);
  97         if (ret)
  98                 return ret;
  99
 100         touch->last_x = ((_x << 2) & 0x3fc) | (_v & 0x3);
 101         touch->last_y = ((_y << 2) & 0x3fc) | ((_v & 0xc) >> 2);
 102
 103         return 0;
 104 }
 105
 106 static inline int start_tsi(struct da9034_touch *touch)
 107 {
 108         return da903x_set_bits(touch->da9034_dev,
 109                         DA9034_AUTO_CTRL2, DA9034_AUTO_TSI_EN);
 110 }
 111
 112 static inline int stop_tsi(struct da9034_touch *touch)
 113 {
 114         return da903x_clr_bits(touch->da9034_dev,
 115                         DA9034_AUTO_CTRL2, DA9034_AUTO_TSI_EN);
 116 }
 117
 118 static inline void report_pen_down(struct da9034_touch *touch)
 119 {
 120         int x = touch->last_x;
 121         int y = touch->last_y;
 122
 123         x &= 0xfff;
 124         if (touch->x_inverted)
 125                 x = 1024 - x;
 126         y &= 0xfff;
 127         if (touch->y_inverted)
 128                 y = 1024 - y;
 129
 130         input_report_abs(touch->input_dev, ABS_X, x);
 131         input_report_abs(touch->input_dev, ABS_Y, y);
 132         input_report_key(touch->input_dev, BTN_TOUCH, 1);
 133
 134         input_sync(touch->input_dev);
 135 }
 136
 137 static inline void report_pen_up(struct da9034_touch *touch)
 138 {
 139         input_report_key(touch->input_dev, BTN_TOUCH, 0);
 140         input_sync(touch->input_dev);
 141 }
 142
 143 static void da9034_event_handler(struct da9034_touch *touch, int event)
 144 {
 145         int err;
 146
 147         switch (touch->state) {
 148         case STATE_IDLE:
 149                 if (event != EVENT_PEN_DOWN)
 150                         break;
 151
 152                 /* Enable auto measurement of the TSI, this will
 153                  * automatically disable pen down detection
 154                  */
 155                 err = start_tsi(touch);
 156                 if (err)
 157                         goto err_reset;
 158
 159                 touch->state = STATE_BUSY;
 160                 break;
 161
 162         case STATE_BUSY:
 163                 if (event != EVENT_TSI_READY)
 164                         break;
 165
 166                 err = read_tsi(touch);
 167                 if (err)
 168                         goto err_reset;
 169
 170                 /* Disable auto measurement of the TSI, so that
 171                  * pen down status will be available
 172                  */
 173                 err = stop_tsi(touch);
 174                 if (err)
 175                         goto err_reset;
 176
 177                 touch->state = STATE_STOP;
 178                 break;
 179
 180         case STATE_STOP:
 181                 if (event == EVENT_PEN_DOWN) {
 182                         report_pen_down(touch);
 183                         schedule_delayed_work(&touch->tsi_work,
 184                                 msecs_to_jiffies(touch->interval_ms));
 185                         touch->state = STATE_WAIT;
 186                 }
 187
 188                 if (event == EVENT_PEN_UP) {
 189                         report_pen_up(touch);
 190                         touch->state = STATE_IDLE;
 191                 }
 192
 193                 input_sync(touch->input_dev);
 194                 break;
 195
 196         case STATE_WAIT:
 197                 if (event != EVENT_TIMEDOUT)
 198                         break;
 199
 200                 if (is_pen_down(touch)) {
 201                         start_tsi(touch);
 202                         touch->state = STATE_BUSY;
 203                 } else
 204                         touch->state = STATE_IDLE;
 205                 break;
 206         }
 207         return;
 208
 209 err_reset:
 210         touch->state = STATE_IDLE;
 211         stop_tsi(touch);
 212         detect_pen_down(touch, 1);
 213 }
 214
 215 static void da9034_tsi_work(struct work_struct *work)
 216 {
 217         struct da9034_touch *touch =
 218                 container_of(work, struct da9034_touch, tsi_work.work);
 219
 220         da9034_event_handler(touch, EVENT_TIMEDOUT);
 221 }
 222
 223 static int da9034_touch_notifier(struct notifier_block *nb,
 224                                  unsigned long event, void *data)
 225 {
 226         struct da9034_touch *touch =
 227                 container_of(nb, struct da9034_touch, notifier);
 228
 229         if (event & DA9034_EVENT_PEN_DOWN) {
 230                 if (is_pen_down(touch))
 231                         da9034_event_handler(touch, EVENT_PEN_DOWN);
 232                 else
 233                         da9034_event_handler(touch, EVENT_PEN_UP);
 234         }
 235
 236         if (event & DA9034_EVENT_TSI_READY)
 237                 da9034_event_handler(touch, EVENT_TSI_READY);
 238
 239         return 0;
 240 }
 241
 242 static int da9034_touch_open(struct input_dev *dev)
 243 {
 244         struct da9034_touch *touch = input_get_drvdata(dev);
 245         int ret;
 246
 247         ret = da903x_register_notifier(touch->da9034_dev, &touch->notifier,
 248                         DA9034_EVENT_PEN_DOWN | DA9034_EVENT_TSI_READY);
 249         if (ret)
 250                 return -EBUSY;
 251
 252         /* Enable ADC LDO */
 253         ret = da903x_set_bits(touch->da9034_dev,
 254                         DA9034_MANUAL_CTRL, DA9034_LDO_ADC_EN);
 255         if (ret)
 256                 return ret;
 257
 258         /* TSI_DELAY: 3 slots, TSI_SKIP: 3 slots */
 259         ret = da903x_write(touch->da9034_dev, DA9034_TSI_CTRL1, 0x1b);
 260         if (ret)
 261                 return ret;
 262
 263         ret = da903x_write(touch->da9034_dev, DA9034_TSI_CTRL2, 0x00);
 264         if (ret)
 265                 return ret;
 266
 267         touch->state = STATE_IDLE;
 268         detect_pen_down(touch, 1);
 269
 270         return 0;
 271 }
 272
 273 static void da9034_touch_close(struct input_dev *dev)
 274 {
 275         struct da9034_touch *touch = input_get_drvdata(dev);
 276
 277         da903x_unregister_notifier(touch->da9034_dev, &touch->notifier,
 278                         DA9034_EVENT_PEN_DOWN | DA9034_EVENT_TSI_READY);
 279
 280         cancel_delayed_work_sync(&touch->tsi_work);
 281
 282         touch->state = STATE_IDLE;
 283         stop_tsi(touch);
 284         detect_pen_down(touch, 0);
 285
 286         /* Disable ADC LDO */
 287         da903x_clr_bits(touch->da9034_dev,
 288                         DA9034_MANUAL_CTRL, DA9034_LDO_ADC_EN);
 289 }
 290
 291
 292 static int __devinit da9034_touch_probe(struct platform_device *pdev)
 293 {
 294         struct da9034_touch_pdata *pdata = pdev->dev.platform_data;
 295         struct da9034_touch *touch;
 296         struct input_dev *input_dev;
 297         int ret;
 298
 299         touch = kzalloc(sizeof(struct da9034_touch), GFP_KERNEL);
 300         if (touch == NULL) {
 301                 dev_err(&pdev->dev, "failed to allocate driver data\n");
 302                 return -ENOMEM;
 303         }
 304
 305         touch->da9034_dev = pdev->dev.parent;
 306
 307         if (pdata) {
 308                 touch->interval_ms      = pdata->interval_ms;
 309                 touch->x_inverted       = pdata->x_inverted;
 310                 touch->y_inverted       = pdata->y_inverted;
 311         } else
 312                 /* fallback into default */
 313                 touch->interval_ms      = 10;
 314
 315         INIT_DELAYED_WORK(&touch->tsi_work, da9034_tsi_work);
 316         touch->notifier.notifier_call = da9034_touch_notifier;
 317
 318         input_dev = input_allocate_device();
 319         if (!input_dev) {
 320                 dev_err(&pdev->dev, "failed to allocate input device\n");
 321                 ret = -ENOMEM;
 322                 goto err_free_touch;
 323         }
 324
 325         input_dev->name         = pdev->name;
 326         input_dev->open         = da9034_touch_open;
 327         input_dev->close        = da9034_touch_close;
 328         input_dev->dev.parent   = &pdev->dev;
 329
 330         __set_bit(EV_ABS, input_dev->evbit);
 331         __set_bit(ABS_X, input_dev->absbit);
 332         __set_bit(ABS_Y, input_dev->absbit);
 333         input_set_abs_params(input_dev, ABS_X, 0, 1023, 0, 0);
 334         input_set_abs_params(input_dev, ABS_Y, 0, 1023, 0, 0);
 335
 336         __set_bit(EV_KEY, input_dev->evbit);
 337         __set_bit(BTN_TOUCH, input_dev->keybit);
 338
 339         touch->input_dev = input_dev;
 340         input_set_drvdata(input_dev, touch);
 341
 342         ret = input_register_device(input_dev);
 343         if (ret)
 344                 goto err_free_input;
 345
 346         platform_set_drvdata(pdev, touch);
 347         return 0;
 348
 349 err_free_input:
 350         input_free_device(input_dev);
 351 err_free_touch:
 352         kfree(touch);
 353         return ret;
 354 }
 355
 356 static int __devexit da9034_touch_remove(struct platform_device *pdev)
 357 {
 358         struct da9034_touch *touch = platform_get_drvdata(pdev);
 359
 360         input_unregister_device(touch->input_dev);
 361         kfree(touch);
 362
 363         return 0;
 364 }
 365
 366 static struct platform_driver da9034_touch_driver = {
 367         .driver = {
 368                 .name   = "da9034-touch",
 369                 .owner  = THIS_MODULE,
 370         },
 371         .probe          = da9034_touch_probe,
 372         .remove         = __devexit_p(da9034_touch_remove),
 373 };
 374
 375 static int __init da9034_touch_init(void)
 376 {
 377         return platform_driver_register(&da9034_touch_driver);
 378 }
 379 module_init(da9034_touch_init);
 380
 381 static void __exit da9034_touch_exit(void)
 382 {
 383         platform_driver_unregister(&da9034_touch_driver);
 384 }
 385 module_exit(da9034_touch_exit);
 386
 387 MODULE_DESCRIPTION("Touchscreen driver for Dialog Semiconductor DA9034");
 388 MODULE_AUTHOR("Eric Miao <eric.miao@marvell.com>");
 389 MODULE_LICENSE("GPL");
 390 MODULE_ALIAS("platform:da9034-touch");