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