git.oblomov.eu Git - linux-2.6/blob - drivers/input/touchscreen/wm9713.c

   1 /*
   2  * wm9713.c  --  Codec touch driver for Wolfson WM9713 AC97 Codec.
   3  *
   4  * Copyright 2003, 2004, 2005, 2006, 2007, 2008 Wolfson Microelectronics PLC.
   5  * Author: Liam Girdwood
   6  *         liam.girdwood@wolfsonmicro.com or linux@wolfsonmicro.com
   7  * Parts Copyright : Ian Molton <spyro@f2s.com>
   8  *                   Andrew Zabolotny <zap@homelink.ru>
   9  *                   Russell King <rmk@arm.linux.org.uk>
  10  *
  11  *  This program is free software; you can redistribute  it and/or modify it
  12  *  under  the terms of  the GNU General  Public License as published by the
  13  *  Free Software Foundation;  either version 2 of the  License, or (at your
  14  *  option) any later version.
  15  *
  16  */
  17
  18 #include <linux/module.h>
  19 #include <linux/moduleparam.h>
  20 #include <linux/version.h>
  21 #include <linux/kernel.h>
  22 #include <linux/input.h>
  23 #include <linux/delay.h>
  24 #include <linux/bitops.h>
  25 #include <linux/wm97xx.h>
  26
  27 #define TS_NAME                 "wm97xx"
  28 #define WM9713_VERSION          "1.00"
  29 #define DEFAULT_PRESSURE        0xb0c0
  30
  31 /*
  32  * Module parameters
  33  */
  34
  35 /*
  36  * Set internal pull up for pen detect.
  37  *
  38  * Pull up is in the range 1.02k (least sensitive) to 64k (most sensitive)
  39  * i.e. pull up resistance = 64k Ohms / rpu.
  40  *
  41  * Adjust this value if you are having problems with pen detect not
  42  * detecting any down event.
  43  */
  44 static int rpu = 8;
  45 module_param(rpu, int, 0);
  46 MODULE_PARM_DESC(rpu, "Set internal pull up resitor for pen detect.");
  47
  48 /*
  49  * Set current used for pressure measurement.
  50  *
  51  * Set pil = 2 to use 400uA
  52  *     pil = 1 to use 200uA and
  53  *     pil = 0 to disable pressure measurement.
  54  *
  55  * This is used to increase the range of values returned by the adc
  56  * when measureing touchpanel pressure.
  57  */
  58 static int pil;
  59 module_param(pil, int, 0);
  60 MODULE_PARM_DESC(pil, "Set current used for pressure measurement.");
  61
  62 /*
  63  * Set threshold for pressure measurement.
  64  *
  65  * Pen down pressure below threshold is ignored.
  66  */
  67 static int pressure = DEFAULT_PRESSURE & 0xfff;
  68 module_param(pressure, int, 0);
  69 MODULE_PARM_DESC(pressure, "Set threshold for pressure measurement.");
  70
  71 /*
  72  * Set adc sample delay.
  73  *
  74  * For accurate touchpanel measurements, some settling time may be
  75  * required between the switch matrix applying a voltage across the
  76  * touchpanel plate and the ADC sampling the signal.
  77  *
  78  * This delay can be set by setting delay = n, where n is the array
  79  * position of the delay in the array delay_table below.
  80  * Long delays > 1ms are supported for completeness, but are not
  81  * recommended.
  82  */
  83 static int delay = 4;
  84 module_param(delay, int, 0);
  85 MODULE_PARM_DESC(delay, "Set adc sample delay.");
  86
  87 /*
  88  * Set five_wire = 1 to use a 5 wire touchscreen.
  89  *
  90  * NOTE: Five wire mode does not allow for readback of pressure.
  91  */
  92 static int five_wire;
  93 module_param(five_wire, int, 0);
  94 MODULE_PARM_DESC(five_wire, "Set to '1' to use 5-wire touchscreen.");
  95
  96 /*
  97  * Set adc mask function.
  98  *
  99  * Sources of glitch noise, such as signals driving an LCD display, may feed
 100  * through to the touch screen plates and affect measurement accuracy. In
 101  * order to minimise this, a signal may be applied to the MASK pin to delay or
 102  * synchronise the sampling.
 103  *
 104  * 0 = No delay or sync
 105  * 1 = High on pin stops conversions
 106  * 2 = Edge triggered, edge on pin delays conversion by delay param (above)
 107  * 3 = Edge triggered, edge on pin starts conversion after delay param
 108  */
 109 static int mask;
 110 module_param(mask, int, 0);
 111 MODULE_PARM_DESC(mask, "Set adc mask function.");
 112
 113 /*
 114  * Coordinate Polling Enable.
 115  *
 116  * Set to 1 to enable coordinate polling. e.g. x,y[,p] is sampled together
 117  * for every poll.
 118  */
 119 static int coord;
 120 module_param(coord, int, 0);
 121 MODULE_PARM_DESC(coord, "Polling coordinate mode");
 122
 123 /*
 124  * ADC sample delay times in uS
 125  */
 126 static const int delay_table[] = {
 127         21,    /* 1 AC97 Link frames */
 128         42,    /* 2 */
 129         84,    /* 4 */
 130         167,   /* 8 */
 131         333,   /* 16 */
 132         667,   /* 32 */
 133         1000,  /* 48 */
 134         1333,  /* 64 */
 135         2000,  /* 96 */
 136         2667,  /* 128 */
 137         3333,  /* 160 */
 138         4000,  /* 192 */
 139         4667,  /* 224 */
 140         5333,  /* 256 */
 141         6000,  /* 288 */
 142         0      /* No delay, switch matrix always on */
 143 };
 144
 145 /*
 146  * Delay after issuing a POLL command.
 147  *
 148  * The delay is 3 AC97 link frames + the touchpanel settling delay
 149  */
 150 static inline void poll_delay(int d)
 151 {
 152         udelay(3 * AC97_LINK_FRAME + delay_table[d]);
 153 }
 154
 155 /*
 156  * set up the physical settings of the WM9713
 157  */
 158 static void wm9713_phy_init(struct wm97xx *wm)
 159 {
 160         u16 dig1 = 0, dig2, dig3;
 161
 162         /* default values */
 163         dig2 = WM97XX_DELAY(4) | WM97XX_SLT(5);
 164         dig3 = WM9712_RPU(1);
 165
 166         /* rpu */
 167         if (rpu) {
 168                 dig3 &= 0xffc0;
 169                 dig3 |= WM9712_RPU(rpu);
 170                 dev_info(wm->dev, "setting pen detect pull-up to %d Ohms\n",
 171                          64000 / rpu);
 172         }
 173
 174         /* Five wire panel? */
 175         if (five_wire) {
 176                 dig3 |= WM9713_45W;
 177                 dev_info(wm->dev, "setting 5-wire touchscreen mode.");
 178
 179                 if (pil) {
 180                         dev_warn(wm->dev,
 181                                  "Pressure measurement not supported in 5 "
 182                                  "wire mode, disabling\n");
 183                         pil = 0;
 184                 }
 185         }
 186
 187         /* touchpanel pressure */
 188         if (pil == 2) {
 189                 dig3 |= WM9712_PIL;
 190                 dev_info(wm->dev,
 191                          "setting pressure measurement current to 400uA.");
 192         } else if (pil)
 193                 dev_info(wm->dev,
 194                          "setting pressure measurement current to 200uA.");
 195         if (!pil)
 196                 pressure = 0;
 197
 198         /* sample settling delay */
 199         if (delay < 0 || delay > 15) {
 200                 dev_info(wm->dev, "supplied delay out of range.");
 201                 delay = 4;
 202                 dev_info(wm->dev, "setting adc sample delay to %d u Secs.",
 203                          delay_table[delay]);
 204         }
 205         dig2 &= 0xff0f;
 206         dig2 |= WM97XX_DELAY(delay);
 207
 208         /* mask */
 209         dig3 |= ((mask & 0x3) << 4);
 210         if (coord)
 211                 dig3 |= WM9713_WAIT;
 212
 213         wm->misc = wm97xx_reg_read(wm, 0x5a);
 214
 215         wm97xx_reg_write(wm, AC97_WM9713_DIG1, dig1);
 216         wm97xx_reg_write(wm, AC97_WM9713_DIG2, dig2);
 217         wm97xx_reg_write(wm, AC97_WM9713_DIG3, dig3);
 218         wm97xx_reg_write(wm, AC97_GPIO_STICKY, 0x0);
 219 }
 220
 221 static void wm9713_dig_enable(struct wm97xx *wm, int enable)
 222 {
 223         u16 val;
 224
 225         if (enable) {
 226                 val = wm97xx_reg_read(wm, AC97_EXTENDED_MID);
 227                 wm97xx_reg_write(wm, AC97_EXTENDED_MID, val & 0x7fff);
 228                 wm97xx_reg_write(wm, AC97_WM9713_DIG3, wm->dig[2] |
 229                                  WM97XX_PRP_DET_DIG);
 230                 wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD); /* dummy read */
 231         } else {
 232                 wm97xx_reg_write(wm, AC97_WM9713_DIG3, wm->dig[2] &
 233                                         ~WM97XX_PRP_DET_DIG);
 234                 val = wm97xx_reg_read(wm, AC97_EXTENDED_MID);
 235                 wm97xx_reg_write(wm, AC97_EXTENDED_MID, val | 0x8000);
 236         }
 237 }
 238
 239 static void wm9713_dig_restore(struct wm97xx *wm)
 240 {
 241         wm97xx_reg_write(wm, AC97_WM9713_DIG1, wm->dig_save[0]);
 242         wm97xx_reg_write(wm, AC97_WM9713_DIG2, wm->dig_save[1]);
 243         wm97xx_reg_write(wm, AC97_WM9713_DIG3, wm->dig_save[2]);
 244 }
 245
 246 static void wm9713_aux_prepare(struct wm97xx *wm)
 247 {
 248         memcpy(wm->dig_save, wm->dig, sizeof(wm->dig));
 249         wm97xx_reg_write(wm, AC97_WM9713_DIG1, 0);
 250         wm97xx_reg_write(wm, AC97_WM9713_DIG2, 0);
 251         wm97xx_reg_write(wm, AC97_WM9713_DIG3, WM97XX_PRP_DET_DIG);
 252 }
 253
 254 static inline int is_pden(struct wm97xx *wm)
 255 {
 256         return wm->dig[2] & WM9713_PDEN;
 257 }
 258
 259 /*
 260  * Read a sample from the WM9713 adc in polling mode.
 261  */
 262 static int wm9713_poll_sample(struct wm97xx *wm, int adcsel, int *sample)
 263 {
 264         u16 dig1;
 265         int timeout = 5 * delay;
 266
 267         if (!wm->pen_probably_down) {
 268                 u16 data = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD);
 269                 if (!(data & WM97XX_PEN_DOWN))
 270                         return RC_PENUP;
 271                 wm->pen_probably_down = 1;
 272         }
 273
 274         /* set up digitiser */
 275         if (adcsel & 0x8000)
 276                 adcsel = 1 << ((adcsel & 0x7fff) + 3);
 277
 278         dig1 = wm97xx_reg_read(wm, AC97_WM9713_DIG1);
 279         dig1 &= ~WM9713_ADCSEL_MASK;
 280
 281         if (wm->mach_ops && wm->mach_ops->pre_sample)
 282                 wm->mach_ops->pre_sample(adcsel);
 283         wm97xx_reg_write(wm, AC97_WM9713_DIG1, dig1 | adcsel | WM9713_POLL);
 284
 285         /* wait 3 AC97 time slots + delay for conversion */
 286         poll_delay(delay);
 287
 288         /* wait for POLL to go low */
 289         while ((wm97xx_reg_read(wm, AC97_WM9713_DIG1) & WM9713_POLL) &&
 290                 timeout) {
 291                 udelay(AC97_LINK_FRAME);
 292                 timeout--;
 293         }
 294
 295         if (timeout <= 0) {
 296                 /* If PDEN is set, we can get a timeout when pen goes up */
 297                 if (is_pden(wm))
 298                         wm->pen_probably_down = 0;
 299                 else
 300                         dev_dbg(wm->dev, "adc sample timeout");
 301                 return RC_PENUP;
 302         }
 303
 304         *sample = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD);
 305         if (wm->mach_ops && wm->mach_ops->post_sample)
 306                 wm->mach_ops->post_sample(adcsel);
 307
 308         /* check we have correct sample */
 309         if ((*sample & WM97XX_ADCSRC_MASK) != ffs(adcsel >> 1) << 12) {
 310                 dev_dbg(wm->dev, "adc wrong sample, read %x got %x", adcsel,
 311                         *sample & WM97XX_ADCSRC_MASK);
 312                 return RC_PENUP;
 313         }
 314
 315         if (!(*sample & WM97XX_PEN_DOWN)) {
 316                 wm->pen_probably_down = 0;
 317                 return RC_PENUP;
 318         }
 319
 320         return RC_VALID;
 321 }
 322
 323 /*
 324  * Read a coordinate from the WM9713 adc in polling mode.
 325  */
 326 static int wm9713_poll_coord(struct wm97xx *wm, struct wm97xx_data *data)
 327 {
 328         u16 dig1;
 329         int timeout = 5 * delay;
 330
 331         if (!wm->pen_probably_down) {
 332                 u16 val = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD);
 333                 if (!(val & WM97XX_PEN_DOWN))
 334                         return RC_PENUP;
 335                 wm->pen_probably_down = 1;
 336         }
 337
 338         /* set up digitiser */
 339         dig1 = wm97xx_reg_read(wm, AC97_WM9713_DIG1);
 340         dig1 &= ~WM9713_ADCSEL_MASK;
 341         if (pil)
 342                 dig1 |= WM9713_ADCSEL_PRES;
 343
 344         if (wm->mach_ops && wm->mach_ops->pre_sample)
 345                 wm->mach_ops->pre_sample(WM97XX_ADCSEL_X | WM97XX_ADCSEL_Y);
 346         wm97xx_reg_write(wm, AC97_WM9713_DIG1,
 347                          dig1 | WM9713_POLL | WM9713_COO);
 348
 349         /* wait 3 AC97 time slots + delay for conversion */
 350         poll_delay(delay);
 351         data->x = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD);
 352         /* wait for POLL to go low */
 353         while ((wm97xx_reg_read(wm, AC97_WM9713_DIG1) & WM9713_POLL)
 354                && timeout) {
 355                 udelay(AC97_LINK_FRAME);
 356                 timeout--;
 357         }
 358
 359         if (timeout <= 0) {
 360                 /* If PDEN is set, we can get a timeout when pen goes up */
 361                 if (is_pden(wm))
 362                         wm->pen_probably_down = 0;
 363                 else
 364                         dev_dbg(wm->dev, "adc sample timeout");
 365                 return RC_PENUP;
 366         }
 367
 368         /* read back data */
 369         data->y = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD);
 370         if (pil)
 371                 data->p = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD);
 372         else
 373                 data->p = DEFAULT_PRESSURE;
 374
 375         if (wm->mach_ops && wm->mach_ops->post_sample)
 376                 wm->mach_ops->post_sample(WM97XX_ADCSEL_X | WM97XX_ADCSEL_Y);
 377
 378         /* check we have correct sample */
 379         if (!(data->x & WM97XX_ADCSEL_X) || !(data->y & WM97XX_ADCSEL_Y))
 380                 goto err;
 381         if (pil && !(data->p & WM97XX_ADCSEL_PRES))
 382                 goto err;
 383
 384         if (!(data->x & WM97XX_PEN_DOWN) || !(data->y & WM97XX_PEN_DOWN)) {
 385                 wm->pen_probably_down = 0;
 386                 return RC_PENUP;
 387         }
 388         return RC_VALID;
 389 err:
 390         return 0;
 391 }
 392
 393 /*
 394  * Sample the WM9713 touchscreen in polling mode
 395  */
 396 static int wm9713_poll_touch(struct wm97xx *wm, struct wm97xx_data *data)
 397 {
 398         int rc;
 399
 400         if (coord) {
 401                 rc = wm9713_poll_coord(wm, data);
 402                 if (rc != RC_VALID)
 403                         return rc;
 404         } else {
 405                 rc = wm9713_poll_sample(wm, WM9713_ADCSEL_X, &data->x);
 406                 if (rc != RC_VALID)
 407                         return rc;
 408                 rc = wm9713_poll_sample(wm, WM9713_ADCSEL_Y, &data->y);
 409                 if (rc != RC_VALID)
 410                         return rc;
 411                 if (pil) {
 412                         rc = wm9713_poll_sample(wm, WM9713_ADCSEL_PRES,
 413                                                 &data->p);
 414                         if (rc != RC_VALID)
 415                                 return rc;
 416                 } else
 417                         data->p = DEFAULT_PRESSURE;
 418         }
 419         return RC_VALID;
 420 }
 421
 422 /*
 423  * Enable WM9713 continuous mode, i.e. touch data is streamed across
 424  * an AC97 slot
 425  */
 426 static int wm9713_acc_enable(struct wm97xx *wm, int enable)
 427 {
 428         u16 dig1, dig2, dig3;
 429         int ret = 0;
 430
 431         dig1 = wm->dig[0];
 432         dig2 = wm->dig[1];
 433         dig3 = wm->dig[2];
 434
 435         if (enable) {
 436                 /* continous mode */
 437                 if (wm->mach_ops->acc_startup &&
 438                         (ret = wm->mach_ops->acc_startup(wm)) < 0)
 439                         return ret;
 440
 441                 dig1 &= ~WM9713_ADCSEL_MASK;
 442                 dig1 |= WM9713_CTC | WM9713_COO | WM9713_ADCSEL_X |
 443                         WM9713_ADCSEL_Y;
 444                 if (pil)
 445                         dig1 |= WM9713_ADCSEL_PRES;
 446                 dig2 &= ~(WM97XX_DELAY_MASK | WM97XX_SLT_MASK  |
 447                         WM97XX_CM_RATE_MASK);
 448                 dig2 |= WM97XX_SLEN | WM97XX_DELAY(delay) |
 449                 WM97XX_SLT(wm->acc_slot) | WM97XX_RATE(wm->acc_rate);
 450                 dig3 |= WM9713_PDEN;
 451         } else {
 452                 dig1 &= ~(WM9713_CTC | WM9713_COO);
 453                 dig2 &= ~WM97XX_SLEN;
 454                 dig3 &= ~WM9713_PDEN;
 455                 if (wm->mach_ops->acc_shutdown)
 456                         wm->mach_ops->acc_shutdown(wm);
 457         }
 458
 459         wm97xx_reg_write(wm, AC97_WM9713_DIG1, dig1);
 460         wm97xx_reg_write(wm, AC97_WM9713_DIG2, dig2);
 461         wm97xx_reg_write(wm, AC97_WM9713_DIG3, dig3);
 462
 463         return ret;
 464 }
 465
 466 struct wm97xx_codec_drv wm9713_codec = {
 467         .id = WM9713_ID2,
 468         .name = "wm9713",
 469         .poll_sample = wm9713_poll_sample,
 470         .poll_touch = wm9713_poll_touch,
 471         .acc_enable = wm9713_acc_enable,
 472         .phy_init = wm9713_phy_init,
 473         .dig_enable = wm9713_dig_enable,
 474         .dig_restore = wm9713_dig_restore,
 475         .aux_prepare = wm9713_aux_prepare,
 476 };
 477 EXPORT_SYMBOL_GPL(wm9713_codec);
 478
 479 /* Module information */
 480 MODULE_AUTHOR("Liam Girdwood <liam.girdwood@wolfsonmicro.com>");
 481 MODULE_DESCRIPTION("WM9713 Touch Screen Driver");
 482 MODULE_LICENSE("GPL");