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