drivers/staging/mrst-touchscreen/intel-mid-touch.c

   1 /*
   2  * intel_mid_touch.c - Intel MID Resistive Touch Screen Driver
   3  *
   4  * Copyright (C) 2008 Intel Corp
   5  *
   6  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   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 as published by
  10  * the Free Software Foundation; version 2 of the License.
  11  *
  12  * This program is distributed in the hope that it will be useful, but
  13  * WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  15  * General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License along
  18  * with this program; ifnot, write to the Free Software Foundation, Inc.,
  19  * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
  20  *
  21  * Questions/Comments/Bug fixes to Sreedhara (sreedhara.ds@intel.com)
  22  *                          Ramesh Agarwal (ramesh.agarwal@intel.com)
  23  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  24  *
  25  * TODO:
  26  *      kill off mrstouch_debug eventually
  27  *      review conversion of r/m/w sequences
  28  *      Replace interrupt mutex abuse
  29  *      Kill of mrstouchdevp pointer
  30  *
  31  */
  32
  33 #include <linux/module.h>
  34 #include <linux/init.h>
  35 #include <linux/input.h>
  36 #include <linux/interrupt.h>
  37 #include <linux/err.h>
  38 #include <linux/param.h>
  39 #include <linux/spi/spi.h>
  40 #include <linux/irq.h>
  41 #include <linux/delay.h>
  42 #include <linux/kthread.h>
  43 #include <asm/intel_scu_ipc.h>
  44
  45
  46 #if defined(MRSTOUCH_DEBUG)
  47 #define mrstouch_debug(fmt, args...)\
  48         do { \
  49                 printk(KERN_DEBUG "\n[MRSTOUCH(%d)] - ", __LINE__); \
  50                 printk(KERN_DEBUG fmt, ##args); \
  51         } while (0);
  52 #else
  53 #define mrstouch_debug(fmt, args...)
  54 #endif
  55
  56 /* PMIC Interrupt registers */
  57 #define PMIC_REG_ID1   0x00 /*PMIC ID1 register */
  58
  59 /* PMIC Interrupt registers */
  60 #define PMIC_REG_INT   0x04 /*PMIC interrupt register */
  61 #define PMIC_REG_MINT  0x05 /*PMIC interrupt mask register */
  62
  63 /* ADC Interrupt registers */
  64 #define PMIC_REG_ADCINT   0x5F /*ADC interrupt register */
  65 #define PMIC_REG_MADCINT  0x60 /*ADC interrupt mask register */
  66
  67 /* ADC Control registers */
  68 #define PMIC_REG_ADCCNTL1    0x61 /*ADC control register */
  69
  70 /* ADC Channel Selection registers */
  71 #define PMICADDR0     0xA4
  72 #define END_OF_CHANNEL 0x1F
  73
  74 /* ADC Result register */
  75 #define PMIC_REG_ADCSNS0H   0x64
  76
  77 /* ADC channels for touch screen */
  78 #define MRST_TS_CHAN10   0xA /* Touch screen X+ connection */
  79 #define MRST_TS_CHAN11   0xB /* Touch screen X- connection */
  80 #define MRST_TS_CHAN12   0xC /* Touch screen Y+ connection */
  81 #define MRST_TS_CHAN13   0xD /* Touch screen Y- connection */
  82
  83 /* Touch screen coordinate constants */
  84 #define TOUCH_PRESSURE          50
  85 #define TOUCH_PRESSURE_FS       100
  86
  87 #define XMOVE_LIMIT     5
  88 #define YMOVE_LIMIT     5
  89 #define XYMOVE_CNT      3
  90
  91 #define MAX_10BIT       ((1<<10)-1)
  92
  93 /* Touch screen channel BIAS constants */
  94 #define XBIAS           0x20
  95 #define YBIAS           0x40
  96 #define ZBIAS           0x80
  97
  98 /* Touch screen coordinates */
  99 #define MIN_X           10
 100 #define MAX_X           1024
 101 #define MIN_Y           10
 102 #define MAX_Y           1024
 103 #define WAIT_ADC_COMPLETION 10
 104
 105 /* PMIC ADC round robin delays */
 106 #define ADC_LOOP_DELAY0 0x0 /* Continuous loop */
 107 #define ADC_LOOP_DELAY1 0x1 /* 4.5  ms approximate */
 108
 109 /* PMIC Vendor Identifiers */
 110 #define PMIC_VENDOR_FS  0 /* PMIC vendor FreeScale */
 111 #define PMIC_VENDOR_MAXIM 1 /* PMIC vendor MAXIM */
 112 #define PMIC_VENDOR_NEC 2 /* PMIC vendor NEC */
 113 #define MRSTOUCH_MAX_CHANNELS 32 /* Maximum ADC channels */
 114
 115 /* Touch screen device structure */
 116 struct mrstouch_dev {
 117         struct spi_device *spi; /* SPI device associated with touch screen */
 118         struct input_dev *input; /* input device for touchscreen*/
 119         char            phys[32]; /* Device name */
 120         struct task_struct *pendet_thrd; /* PENDET interrupt handler */
 121         struct mutex lock; /* Sync between interrupt and PENDET handler */
 122         bool            busy; /* Busy flag */
 123         u16             asr; /* Address selection register */
 124         int             irq;    /* Touch screen IRQ # */
 125         uint            vendor;  /* PMIC vendor */
 126         uint            rev;  /* PMIC revision */
 127         bool            suspended; /* Device suspended status */
 128         bool            disabled;  /* Device disabled status */
 129         u16             x;  /* X coordinate */
 130         u16             y;  /* Y coordinate */
 131         bool            pendown;  /* PEN position */
 132 } ;
 133
 134
 135 /* Global Pointer to Touch screen device */
 136 static struct mrstouch_dev *mrstouchdevp;
 137
 138 /* Utility to read PMIC ID */
 139 static int mrstouch_pmic_id(uint *vendor, uint *rev)
 140 {
 141         int err;
 142         u8 r;
 143
 144         err = intel_scu_ipc_ioread8(PMIC_REG_ID1, &r);
 145         if (err)
 146                 return err;
 147
 148         *vendor = r & 0x7;
 149         *rev = (r >> 3) & 0x7;
 150
 151         return 0;
 152 }
 153
 154 /*
 155  * Parse ADC channels to find end of the channel configured by other ADC user
 156  * NEC and MAXIM requires 4 channels and FreeScale needs 18 channels
 157  */
 158 static int mrstouch_chan_parse(struct mrstouch_dev *tsdev)
 159 {
 160         int err, i, j, found;
 161         u32 r32;
 162
 163         found = -1;
 164
 165         for (i = 0; i < MRSTOUCH_MAX_CHANNELS; i++) {
 166                 if (found >= 0)
 167                         break;
 168
 169                 err = intel_scu_ipc_ioread32(PMICADDR0, &r32);
 170                 if (err)
 171                         return err;
 172
 173                 for (j = 0; j < 32; j+= 8) {
 174                         if (((r32 >> j) & 0xFF) == END_OF_CHANNEL) {
 175                                 found = i;
 176                                 break;
 177                         }
 178                 }
 179         }
 180         if (found < 0)
 181                 return 0;
 182
 183         if (tsdev->vendor == PMIC_VENDOR_FS) {
 184                 if (found && found > (MRSTOUCH_MAX_CHANNELS - 18))
 185                         return -ENOSPC;
 186         } else {
 187                 if (found && found > (MRSTOUCH_MAX_CHANNELS - 4))
 188                         return -ENOSPC;
 189         }
 190         return found;
 191 }
 192
 193 /* Utility to enable/disable pendet.
 194  * pendet set to true enables PENDET interrupt
 195  * pendet set to false disables PENDET interrupt
 196  * Also clears RND mask bit
 197 */
 198 static int pendet_enable(struct mrstouch_dev *tsdev, bool pendet)
 199 {
 200         u16 reg;
 201         u8 r;
 202         u8 pendet_enabled = 0;
 203         int retry = 0;
 204         int err;
 205
 206         err = intel_scu_ipc_ioread16(PMIC_REG_MADCINT, &reg);
 207         if (err)
 208                 return err;
 209
 210         if (pendet) {
 211                 reg &= ~0x0005;
 212                 reg |= 0x2000; /* Enable pendet */
 213         } else
 214                 reg &= 0xDFFF; /* Disable pendet */
 215
 216         /* Set MADCINT and update ADCCNTL1 (next reg byte) */
 217         err = intel_scu_ipc_iowrite16(PMIC_REG_MADCINT, reg);
 218         if (!pendet || err)
 219                 return err;
 220
 221         /*
 222          * Sometimes even after the register write succeeds
 223          * the PMIC register value is not updated. Retry few iterations
 224          * to enable pendet.
 225          */
 226
 227         err = intel_scu_ipc_ioread8(PMIC_REG_ADCCNTL1, &r);
 228         pendet_enabled = (r >> 5) & 0x01;
 229
 230         retry = 0;
 231         while (!err && !pendet_enabled) {
 232                 retry++;
 233                 msleep(10);
 234                 err = intel_scu_ipc_iowrite8(PMIC_REG_ADCCNTL1, reg >> 8);
 235                 if (err)
 236                         break;
 237                 err = intel_scu_ipc_ioread8(PMIC_REG_ADCCNTL1, &r);
 238                 if (err == 0)
 239                         pendet_enabled = (r >> 5) & 0x01;
 240                 if (retry >= 10) {
 241                         dev_err(&tsdev->spi->dev, "Touch screen disabled.\n");
 242                         return -EIO;
 243                 }
 244         }
 245         return 0;
 246 }
 247
 248 /* To read PMIC ADC touch screen result
 249  * Reads ADC storage registers for higher 7 and lower 3 bits
 250  * converts the two readings to single value and turns off gain bit
 251  */
 252 static int mrstouch_ts_chan_read(u16 offset, u16 chan, u16 *vp, u16 *vm)
 253 {
 254         int err;
 255         u16 result;
 256         u32 res;
 257
 258         result = PMIC_REG_ADCSNS0H + offset;
 259
 260         if (chan == MRST_TS_CHAN12)
 261                 result += 4;
 262
 263         err = intel_scu_ipc_ioread32(result, &res);
 264         if (err)
 265                 return err;
 266
 267         /* Mash the bits up */
 268
 269         *vp = (res & 0xFF) << 3;        /* Highest 7 bits */
 270         *vp |= (res >> 8) & 0x07;       /* Lower 3 bits */
 271         *vp &= 0x3FF;
 272
 273         res >>= 16;
 274
 275         *vm = (res & 0xFF) << 3;        /* Highest 7 bits */
 276         *vm |= (res >> 8) & 0x07;       /* Lower 3 bits */
 277         *vm &= 0x3FF;
 278
 279         return 0;
 280 }
 281
 282 /* To configure touch screen channels
 283  * Writes touch screen channels to ADC address selection registers
 284  */
 285 static int mrstouch_ts_chan_set(uint offset)
 286 {
 287         int count;
 288         u16 chan;
 289         u16 reg[5];
 290         u8 data[5];
 291
 292         chan = PMICADDR0 + offset;
 293         for (count = 0; count <= 3; count++) {
 294                 reg[count] = chan++;
 295                 data[count] = MRST_TS_CHAN10 + count;
 296         }
 297         reg[count] = chan;
 298         data[count] = END_OF_CHANNEL;
 299
 300         return intel_scu_ipc_writev(reg, data, 5);
 301 }
 302
 303 /* Initialize ADC */
 304 static int mrstouch_adc_init(struct mrstouch_dev *tsdev)
 305 {
 306         int err, start;
 307         u8 ra, rm;
 308
 309         err = mrstouch_pmic_id(&tsdev->vendor, &tsdev->rev);
 310         if (err) {
 311                 dev_err(&tsdev->spi->dev, "Unable to read PMIC id\n");
 312                 return err;
 313         }
 314
 315         start = mrstouch_chan_parse(tsdev);
 316         if (start < 0) {
 317                 dev_err(&tsdev->spi->dev, "Unable to parse channels\n");
 318                 return start;
 319         }
 320
 321         tsdev->asr = start;
 322
 323         mrstouch_debug("Channel offset(%d): 0x%X\n", tsdev->asr, tsdev->vendor);
 324
 325         /* ADC power on, start, enable PENDET and set loop delay
 326          * ADC loop delay is set to 4.5 ms approximately
 327          * Loop delay more than this results in jitter in adc readings
 328          * Setting loop delay to 0 (continous loop) in MAXIM stops PENDET
 329          * interrupt generation sometimes.
 330          */
 331
 332         if (tsdev->vendor == PMIC_VENDOR_FS) {
 333                 ra = 0xE0 | ADC_LOOP_DELAY0;
 334                 rm = 0x5;
 335         } else {
 336                 /* NEC and MAXIm not consistent with loop delay 0 */
 337                 ra = 0xE0 | ADC_LOOP_DELAY1;
 338                 rm = 0x0;
 339
 340                 /* configure touch screen channels */
 341                 err = mrstouch_ts_chan_set(tsdev->asr);
 342                 if (err)
 343                         return err;
 344         }
 345         err = intel_scu_ipc_update_register(PMIC_REG_ADCCNTL1, ra, 0xE7);
 346         if (err == 0)
 347                 err = intel_scu_ipc_update_register(PMIC_REG_MADCINT, rm, 0x03);
 348         return err;
 349 }
 350
 351 /* Reports x,y coordinates to event subsystem */
 352 static void mrstouch_report_xy(struct mrstouch_dev *tsdev, u16 x, u16 y, u16 z)
 353 {
 354         int xdiff, ydiff;
 355
 356         if (tsdev->pendown && z <= TOUCH_PRESSURE) {
 357                 /* Pen removed, report button release */
 358                 mrstouch_debug("BTN REL(%d)", z);
 359                 input_report_key(tsdev->input, BTN_TOUCH, 0);
 360                 tsdev->pendown = false;
 361         }
 362
 363         xdiff = abs(x - tsdev->x);
 364         ydiff = abs(y - tsdev->y);
 365
 366         /*
 367         if x and y values changes for XYMOVE_CNT readings it is considered
 368         as stylus is moving. This is required to differentiate between stylus
 369         movement and jitter
 370         */
 371         if (x < MIN_X || x > MAX_X || y < MIN_Y || y > MAX_Y) {
 372                 /* Spurious values, release button if touched and return */
 373                 if (tsdev->pendown) {
 374                         mrstouch_debug("BTN REL(%d)", z);
 375                         input_report_key(tsdev->input, BTN_TOUCH, 0);
 376                         tsdev->pendown = false;
 377                 }
 378                 return;
 379         } else if (xdiff >= XMOVE_LIMIT || ydiff >= YMOVE_LIMIT) {
 380                 tsdev->x = x;
 381                 tsdev->y = y;
 382
 383                 input_report_abs(tsdev->input, ABS_X, x);
 384                 input_report_abs(tsdev->input, ABS_Y, y);
 385                 input_sync(tsdev->input);
 386         }
 387
 388
 389         if (!tsdev->pendown && z > TOUCH_PRESSURE) {
 390                 /* Pen touched, report button touch */
 391                 mrstouch_debug("BTN TCH(%d, %d, %d)", x, y, z);
 392                 input_report_key(tsdev->input, BTN_TOUCH, 1);
 393                 tsdev->pendown = true;
 394         }
 395 }
 396
 397
 398 /* Utility to start ADC, used by freescale handler */
 399 static int pendet_mask(void)
 400 {
 401         return  intel_scu_ipc_update_register(PMIC_REG_MADCINT, 0x02, 0x02);
 402 }
 403
 404 /* Utility to stop ADC, used by freescale handler */
 405 static int pendet_umask(void)
 406 {
 407         return  intel_scu_ipc_update_register(PMIC_REG_MADCINT, 0x00, 0x02);
 408 }
 409
 410 /* Utility to read ADC, used by freescale handler */
 411 static int mrstouch_pmic_fs_adc_read(struct mrstouch_dev *tsdev)
 412 {
 413         int err;
 414         u16 x, y, z, result;
 415         u16 reg[4];
 416         u8 data[4];
 417
 418         result = PMIC_REG_ADCSNS0H + tsdev->asr;
 419
 420         reg[0] = result + 4;
 421         reg[1] = result + 5;
 422         reg[2] = result + 16;
 423         reg[3] = result + 17;
 424
 425         err = intel_scu_ipc_readv(reg, data, 4);
 426         if (err)
 427                 goto ipc_error;
 428
 429         x = data[0] << 3; /* Higher 7 bits */
 430         x |= data[1] & 0x7; /* Lower 3 bits */
 431         x &= 0x3FF;
 432
 433         y = data[2] << 3; /* Higher 7 bits */
 434         y |= data[3] & 0x7; /* Lower 3 bits */
 435         y &= 0x3FF;
 436
 437         /* Read Z value */
 438         reg[0] = result + 28;
 439         reg[1] = result + 29;
 440
 441         err = intel_scu_ipc_readv(reg, data, 4);
 442         if (err)
 443                 goto ipc_error;
 444
 445         z = data[0] << 3; /* Higher 7 bits */
 446         z |= data[1] & 0x7; /* Lower 3 bits */
 447         z &= 0x3FF;
 448
 449 #if defined(MRSTOUCH_PRINT_XYZP)
 450         mrstouch_debug("X: %d, Y: %d, Z: %d", x, y, z);
 451 #endif
 452
 453         if (z >= TOUCH_PRESSURE_FS) {
 454                 mrstouch_report_xy(tsdev, x, y, TOUCH_PRESSURE - 1); /* Pen Removed */
 455                 return TOUCH_PRESSURE - 1;
 456         } else {
 457                 mrstouch_report_xy(tsdev, x, y, TOUCH_PRESSURE + 1); /* Pen Touched */
 458                 return TOUCH_PRESSURE + 1;
 459         }
 460
 461         return 0;
 462
 463 ipc_error:
 464         dev_err(&tsdev->spi->dev, "ipc error during fs_adc read\n");
 465         return err;
 466 }
 467
 468 /* To handle free scale pmic pendet interrupt */
 469 static int pmic0_pendet(void *dev_id)
 470 {
 471         int err, count;
 472         u16 chan;
 473         unsigned int touched;
 474         struct mrstouch_dev *tsdev = (struct mrstouch_dev *)dev_id;
 475         u16 reg[5];
 476         u8 data[5];
 477
 478         chan = PMICADDR0 + tsdev->asr;
 479
 480         /* Set X BIAS */
 481         for (count = 0; count <= 3; count++) {
 482                 reg[count] = chan++;
 483                 data[count] = 0x2A;
 484         }
 485         reg[count] =  chan++; /* Dummy */
 486         data[count] = 0;
 487
 488         err = intel_scu_ipc_writev(reg, data, 5);
 489         if (err)
 490                 goto ipc_error;
 491
 492         msleep(WAIT_ADC_COMPLETION);
 493
 494         /* Set Y BIAS */
 495         for (count = 0; count <= 3; count++) {
 496                 reg[count] = chan++;
 497                 data[count] = 0x4A;
 498         }
 499         reg[count] = chan++; /* Dummy */
 500         data[count] = 0;
 501
 502         err = intel_scu_ipc_writev(reg, data, 5);
 503         if (err)
 504                 goto ipc_error;
 505
 506         msleep(WAIT_ADC_COMPLETION);
 507
 508         /* Set Z BIAS */
 509         err = intel_scu_ipc_iowrite32(chan + 2, 0x8A8A8A8A);
 510         if (err)
 511                 goto ipc_error;
 512
 513         msleep(WAIT_ADC_COMPLETION);
 514
 515         /*Read touch screen channels till pen removed
 516          * Freescale reports constant value of z for all points
 517          * z is high when screen is not touched and low when touched
 518          * Map high z value to not touched and low z value to pen touched
 519          */
 520         touched = mrstouch_pmic_fs_adc_read(tsdev);
 521         while (touched > TOUCH_PRESSURE) {
 522                 touched = mrstouch_pmic_fs_adc_read(tsdev);
 523                 msleep(WAIT_ADC_COMPLETION);
 524         }
 525
 526         /* Clear all TS channels */
 527         chan = PMICADDR0 + tsdev->asr;
 528         for (count = 0; count <= 4; count++) {
 529                 reg[count] = chan++;
 530                 data[count] = 0;
 531         }
 532         err = intel_scu_ipc_writev(reg, data, 5);
 533         if (err)
 534                 goto ipc_error;
 535
 536         for (count = 0; count <= 4; count++) {
 537                 reg[count] = chan++;
 538                 data[count] = 0;
 539         }
 540         err = intel_scu_ipc_writev(reg, data, 5);
 541         if (err)
 542                 goto ipc_error;
 543
 544         err = intel_scu_ipc_iowrite32(chan + 2, 0x00000000);
 545         if (err)
 546                 goto ipc_error;
 547
 548         return 0;
 549
 550 ipc_error:
 551         dev_err(&tsdev->spi->dev, "ipc error during pendet\n");
 552         return err;
 553 }
 554
 555
 556 /* To enable X, Y and Z bias values
 557  * Enables YPYM for X channels and XPXM for Y channels
 558  */
 559 static int mrstouch_ts_bias_set(uint offset, uint bias)
 560 {
 561         int count;
 562         u16 chan, start;
 563         u16 reg[4];
 564         u8 data[4];
 565
 566         chan = PMICADDR0 + offset;
 567         start = MRST_TS_CHAN10;
 568
 569         for (count = 0; count <= 3; count++) {
 570                 reg[count] = chan++;
 571                 data[count] = bias | (start + count);
 572         }
 573         return intel_scu_ipc_writev(reg, data, 4);
 574 }
 575
 576 /* To read touch screen channel values */
 577 static int mrstouch_adc_read(struct mrstouch_dev *tsdev)
 578 {
 579         int err;
 580         u16 xp, xm, yp, ym, zp, zm;
 581
 582         /* configure Y bias for X channels */
 583         err = mrstouch_ts_bias_set(tsdev->asr, YBIAS);
 584         if (err)
 585                 goto ipc_error;
 586
 587         msleep(WAIT_ADC_COMPLETION);
 588
 589         /* read x+ and x- channels */
 590         err = mrstouch_ts_chan_read(tsdev->asr, MRST_TS_CHAN10, &xp, &xm);
 591         if (err)
 592                 goto ipc_error;
 593
 594         /* configure x bias for y channels */
 595         err = mrstouch_ts_bias_set(tsdev->asr, XBIAS);
 596         if (err)
 597                 goto ipc_error;
 598
 599         msleep(WAIT_ADC_COMPLETION);
 600
 601         /* read y+ and y- channels */
 602         err = mrstouch_ts_chan_read(tsdev->asr, MRST_TS_CHAN12, &yp, &ym);
 603         if (err)
 604                 goto ipc_error;
 605
 606         /* configure z bias for x and y channels */
 607         err = mrstouch_ts_bias_set(tsdev->asr, ZBIAS);
 608         if (err)
 609                 goto ipc_error;
 610
 611         msleep(WAIT_ADC_COMPLETION);
 612
 613         /* read z+ and z- channels */
 614         err = mrstouch_ts_chan_read(tsdev->asr, MRST_TS_CHAN10, &zp, &zm);
 615         if (err)
 616                 goto ipc_error;
 617
 618 #if defined(MRSTOUCH_PRINT_XYZP)
 619         printk(KERN_INFO "X+: %d, Y+: %d, Z+: %d\n", xp, yp, zp);
 620 #endif
 621
 622 #if defined(MRSTOUCH_PRINT_XYZM)
 623         printk(KERN_INFO "X-: %d, Y-: %d, Z-: %d\n", xm, ym, zm);
 624 #endif
 625
 626         mrstouch_report_xy(tsdev, xp, yp, zp); /* report x and y to eventX */
 627
 628         return zp;
 629
 630 ipc_error:
 631         dev_err(&tsdev->spi->dev, "ipc error during adc read\n");
 632         return err;
 633 }
 634
 635 /* PENDET interrupt handler function for NEC and MAXIM */
 636 static void pmic12_pendet(void *data)
 637 {
 638         unsigned int touched;
 639         struct mrstouch_dev *tsdev = (struct mrstouch_dev *)data;
 640
 641         /* read touch screen channels till pen removed */
 642         do {
 643                 touched = mrstouch_adc_read(tsdev);
 644         } while (touched > TOUCH_PRESSURE);
 645 }
 646
 647 /* Handler to process PENDET interrupt */
 648 int mrstouch_pendet(void *data)
 649 {
 650         struct mrstouch_dev *tsdev = (struct mrstouch_dev *)data;
 651         while (1) {
 652                 /* Wait for PENDET interrupt */
 653                 if (mutex_lock_interruptible(&tsdev->lock)) {
 654                         msleep(WAIT_ADC_COMPLETION);
 655                         continue;
 656                 }
 657
 658                 if (tsdev->busy)
 659                         return 0;
 660
 661                 tsdev->busy = true;
 662
 663                 if (tsdev->vendor == PMIC_VENDOR_NEC ||
 664                         tsdev->vendor == PMIC_VENDOR_MAXIM) {
 665                         /* PENDET must be disabled in NEC before reading ADC */
 666                         pendet_enable(tsdev,false); /* Disbale PENDET */
 667                         pmic12_pendet(tsdev);
 668                         pendet_enable(tsdev, true); /*Enable PENDET */
 669                 } else if (tsdev->vendor == PMIC_VENDOR_FS) {
 670                         pendet_umask(); /* Stop ADC */
 671                         pmic0_pendet(tsdev);
 672                         pendet_mask(); /* Stop ADC */
 673                 } else
 674                 dev_err(&tsdev->spi->dev, "Unsupported touchscreen: %d\n",
 675                                 tsdev->vendor);
 676
 677                 tsdev->busy = false;
 678
 679         }
 680         return 0;
 681 }
 682
 683 /* PENDET interrupt handler */
 684 static irqreturn_t pendet_intr_handler(int irq, void *handle)
 685 {
 686         struct mrstouch_dev *tsdev = (struct mrstouch_dev *)handle;
 687
 688         mutex_unlock(&tsdev->lock);
 689         return IRQ_HANDLED;
 690 }
 691
 692 /* Intializes input device and registers with input subsystem */
 693 static int ts_input_dev_init(struct mrstouch_dev *tsdev, struct spi_device *spi)
 694 {
 695         int err = 0;
 696
 697         mrstouch_debug("%s", __func__);
 698
 699         tsdev->input = input_allocate_device();
 700         if (!tsdev->input) {
 701                 dev_err(&tsdev->spi->dev, "Unable to allocate input device.\n");
 702                 return -EINVAL;
 703         }
 704
 705         tsdev->input->name = "mrst_touchscreen";
 706         snprintf(tsdev->phys, sizeof(tsdev->phys),
 707                         "%s/input0", dev_name(&spi->dev));
 708         tsdev->input->phys = tsdev->phys;
 709         tsdev->input->dev.parent = &spi->dev;
 710
 711         tsdev->input->id.vendor = tsdev->vendor;
 712         tsdev->input->id.version = tsdev->rev;
 713
 714         tsdev->input->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
 715         tsdev->input->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
 716
 717         input_set_abs_params(tsdev->input, ABS_X, MIN_X, MIN_Y, 0, 0);
 718         input_set_abs_params(tsdev->input, ABS_Y, MIN_X, MIN_Y, 0, 0);
 719
 720         err = input_register_device(tsdev->input);
 721         if (err) {
 722                 dev_err(&tsdev->spi->dev, "unable to register input device\n");
 723                 input_free_device(tsdev->input);
 724                 return err;
 725         }
 726
 727         mrstouch_debug("%s", "mrstouch initialized");
 728
 729         return 0;
 730
 731 }
 732
 733 /* Probe function for touch screen driver */
 734 static int __devinit mrstouch_probe(struct spi_device *mrstouch_spi)
 735 {
 736         int err;
 737         unsigned int myirq;
 738         struct mrstouch_dev *tsdev;
 739
 740         mrstouch_debug("%s(%p)", __func__, mrstouch_spi);
 741
 742         mrstouchdevp = NULL;
 743         myirq = mrstouch_spi->irq;
 744
 745         if (!mrstouch_spi->irq) {
 746                 dev_err(&mrstouch_spi->dev, "no interrupt assigned\n");
 747                 return -EINVAL;
 748         }
 749
 750         tsdev = kzalloc(sizeof(struct mrstouch_dev), GFP_KERNEL);
 751         if (!tsdev) {
 752                 dev_err(&mrstouch_spi->dev, "unable to allocate memory\n");
 753                 return -ENOMEM;
 754         }
 755
 756         tsdev->irq = myirq;
 757         mrstouchdevp = tsdev;
 758
 759         err = mrstouch_adc_init(tsdev);
 760         if (err) {
 761                 dev_err(&mrstouch_spi->dev, "ADC init failed\n");
 762                 goto mrstouch_err_free_mem;
 763         }
 764
 765         dev_set_drvdata(&mrstouch_spi->dev, tsdev);
 766         tsdev->spi = mrstouch_spi;
 767
 768         err = ts_input_dev_init(tsdev, mrstouch_spi);
 769         if (err) {
 770                 dev_err(&tsdev->spi->dev, "ts_input_dev_init failed");
 771                 goto mrstouch_err_free_mem;
 772         }
 773
 774         mutex_init(&tsdev->lock);
 775         mutex_lock(&tsdev->lock)
 776
 777         mrstouch_debug("Requesting IRQ-%d", myirq);
 778         err = request_irq(myirq, pendet_intr_handler,
 779                                 0, "mrstouch", tsdev);
 780         if (err) {
 781                 dev_err(&tsdev->spi->dev, "unable to allocate irq\n");
 782                 goto mrstouch_err_free_mem;
 783         }
 784
 785         tsdev->pendet_thrd = kthread_run(mrstouch_pendet,
 786                                 (void *)tsdev, "pendet handler");
 787         if (IS_ERR(tsdev->pendet_thrd)) {
 788                 dev_err(&tsdev->spi->dev, "kthread_run failed\n");
 789                 err = PTR_ERR(tsdev->pendet_thrd);
 790                 goto mrstouch_err_free_mem;
 791         }
 792         mrstouch_debug("%s", "Driver initialized");
 793         return 0;
 794
 795 mrstouch_err_free_mem:
 796         kfree(tsdev);
 797         return err;
 798 }
 799
 800 static int mrstouch_suspend(struct spi_device *spi, pm_message_t msg)
 801 {
 802         mrstouch_debug("%s", __func__);
 803         mrstouchdevp->suspended = 1;
 804         return 0;
 805 }
 806
 807 static int mrstouch_resume(struct spi_device *spi)
 808 {
 809         mrstouch_debug("%s", __func__);
 810         mrstouchdevp->suspended = 0;
 811         return 0;
 812 }
 813
 814 static int mrstouch_remove(struct spi_device *spi)
 815 {
 816         mrstouch_debug("%s", __func__);
 817         free_irq(mrstouchdevp->irq, mrstouchdevp);
 818         input_unregister_device(mrstouchdevp->input);
 819         input_free_device(mrstouchdevp->input);
 820         kfree(mrstouchdevp);
 821         if (mrstouchdevp->pendet_thrd)
 822                 kthread_stop(mrstouchdevp->pendet_thrd);
 823         return 0;
 824 }
 825
 826 static struct spi_driver mrstouch_driver = {
 827         .driver = {
 828                 .name   = "pmic_touch",
 829                 .bus    = &spi_bus_type,
 830                 .owner  = THIS_MODULE,
 831         },
 832         .probe          = mrstouch_probe,
 833         .suspend        = mrstouch_suspend,
 834         .resume         = mrstouch_resume,
 835         .remove         = mrstouch_remove,
 836 };
 837
 838 static int __init mrstouch_module_init(void)
 839 {
 840         int err;
 841
 842         mrstouch_debug("%s", __func__);
 843         err = spi_register_driver(&mrstouch_driver);
 844         if (err) {
 845                 mrstouch_debug("%s(%d)", "SPI PENDET failed", err);
 846                 return -1;
 847         }
 848
 849         return 0;
 850 }
 851
 852 static void __exit mrstouch_module_exit(void)
 853 {
 854         mrstouch_debug("%s", __func__);
 855         spi_unregister_driver(&mrstouch_driver);
 856         return;
 857 }
 858
 859 module_init(mrstouch_module_init);
 860 module_exit(mrstouch_module_exit);
 861
 862 MODULE_AUTHOR("Sreedhara Murthy. D.S, sreedhara.ds@intel.com");
 863 MODULE_DESCRIPTION("Intel Moorestown Resistive Touch Screen Driver");
 864 MODULE_LICENSE("GPL");