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