LXR linux/drivers/input/touchscreen/intel-mid-touch.c

   1/*
   2 * 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; if not, 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 *      review conversion of r/m/w sequences
  27 */
  28
  29#include <linux/module.h>
  30#include <linux/init.h>
  31#include <linux/input.h>
  32#include <linux/interrupt.h>
  33#include <linux/err.h>
  34#include <linux/param.h>
  35#include <linux/slab.h>
  36#include <linux/platform_device.h>
  37#include <linux/irq.h>
  38#include <linux/delay.h>
  39#include <asm/intel_scu_ipc.h>
  40
  41/* PMIC Interrupt registers */
  42#define PMIC_REG_ID1            0x00 /* PMIC ID1 register */
  43
  44/* PMIC Interrupt registers */
  45#define PMIC_REG_INT            0x04 /* PMIC interrupt register */
  46#define PMIC_REG_MINT           0x05 /* PMIC interrupt mask register */
  47
  48/* ADC Interrupt registers */
  49#define PMIC_REG_ADCINT         0x5F /* ADC interrupt register */
  50#define PMIC_REG_MADCINT        0x60 /* ADC interrupt mask register */
  51
  52/* ADC Control registers */
  53#define PMIC_REG_ADCCNTL1       0x61 /* ADC control register */
  54
  55/* ADC Channel Selection registers */
  56#define PMICADDR0               0xA4
  57#define END_OF_CHANNEL          0x1F
  58
  59/* ADC Result register */
  60#define PMIC_REG_ADCSNS0H       0x64
  61
  62/* ADC channels for touch screen */
  63#define MRST_TS_CHAN10          0xA /* Touch screen X+ connection */
  64#define MRST_TS_CHAN11          0xB /* Touch screen X- connection */
  65#define MRST_TS_CHAN12          0xC /* Touch screen Y+ connection */
  66#define MRST_TS_CHAN13          0xD /* Touch screen Y- connection */
  67
  68/* Touch screen channel BIAS constants */
  69#define MRST_XBIAS              0x20
  70#define MRST_YBIAS              0x40
  71#define MRST_ZBIAS              0x80
  72
  73/* Touch screen coordinates */
  74#define MRST_X_MIN              10
  75#define MRST_X_MAX              1024
  76#define MRST_X_FUZZ             5
  77#define MRST_Y_MIN              10
  78#define MRST_Y_MAX              1024
  79#define MRST_Y_FUZZ             5
  80#define MRST_PRESSURE_MIN       0
  81#define MRST_PRESSURE_NOMINAL   50
  82#define MRST_PRESSURE_MAX       100
  83
  84#define WAIT_ADC_COMPLETION     10 /* msec */
  85
  86/* PMIC ADC round robin delays */
  87#define ADC_LOOP_DELAY0         0x0 /* Continuous loop */
  88#define ADC_LOOP_DELAY1         0x1 /* 4.5  ms approximate */
  89
  90/* PMIC Vendor Identifiers */
  91#define PMIC_VENDOR_FS          0 /* PMIC vendor FreeScale */
  92#define PMIC_VENDOR_MAXIM       1 /* PMIC vendor MAXIM */
  93#define PMIC_VENDOR_NEC         2 /* PMIC vendor NEC */
  94#define MRSTOUCH_MAX_CHANNELS   32 /* Maximum ADC channels */
  95
  96/* Touch screen device structure */
  97struct mrstouch_dev {
  98        struct device *dev; /* device associated with touch screen */
  99        struct input_dev *input;
 100        char phys[32];
 101        u16 asr;                /* Address selection register */
 102        int irq;
 103        unsigned int vendor;    /* PMIC vendor */
 104        unsigned int rev;       /* PMIC revision */
 105
 106        int (*read_prepare)(struct mrstouch_dev *tsdev);
 107        int (*read)(struct mrstouch_dev *tsdev, u16 *x, u16 *y, u16 *z);
 108        int (*read_finish)(struct mrstouch_dev *tsdev);
 109};
 110
 111
 112/*************************** NEC and Maxim Interface ************************/
 113
 114static int mrstouch_nec_adc_read_prepare(struct mrstouch_dev *tsdev)
 115{
 116        return intel_scu_ipc_update_register(PMIC_REG_MADCINT, 0, 0x20);
 117}
 118
 119/*
 120 * Enables PENDET interrupt.
 121 */
 122static int mrstouch_nec_adc_read_finish(struct mrstouch_dev *tsdev)
 123{
 124        int err;
 125
 126        err = intel_scu_ipc_update_register(PMIC_REG_MADCINT, 0x20, 0x20);
 127        if (!err)
 128                err = intel_scu_ipc_update_register(PMIC_REG_ADCCNTL1, 0, 0x05);
 129
 130        return err;
 131}
 132
 133/*
 134 * Reads PMIC ADC touch screen result
 135 * Reads ADC storage registers for higher 7 and lower 3 bits and
 136 * converts the two readings into a single value and turns off gain bit
 137 */
 138static int mrstouch_ts_chan_read(u16 offset, u16 chan, u16 *vp, u16 *vm)
 139{
 140        int err;
 141        u16 result;
 142        u32 res;
 143
 144        result = PMIC_REG_ADCSNS0H + offset;
 145
 146        if (chan == MRST_TS_CHAN12)
 147                result += 4;
 148
 149        err = intel_scu_ipc_ioread32(result, &res);
 150        if (err)
 151                return err;
 152
 153        /* Mash the bits up */
 154
 155        *vp = (res & 0xFF) << 3;        /* Highest 7 bits */
 156        *vp |= (res >> 8) & 0x07;       /* Lower 3 bits */
 157        *vp &= 0x3FF;
 158
 159        res >>= 16;
 160
 161        *vm = (res & 0xFF) << 3;        /* Highest 7 bits */
 162        *vm |= (res >> 8) & 0x07;       /* Lower 3 bits */
 163        *vm &= 0x3FF;
 164
 165        return 0;
 166}
 167
 168/*
 169 * Enables X, Y and Z bias values
 170 * Enables YPYM for X channels and XPXM for Y channels
 171 */
 172static int mrstouch_ts_bias_set(uint offset, uint bias)
 173{
 174        int count;
 175        u16 chan, start;
 176        u16 reg[4];
 177        u8 data[4];
 178
 179        chan = PMICADDR0 + offset;
 180        start = MRST_TS_CHAN10;
 181
 182        for (count = 0; count <= 3; count++) {
 183                reg[count] = chan++;
 184                data[count] = bias | (start + count);
 185        }
 186
 187        return intel_scu_ipc_writev(reg, data, 4);
 188}
 189
 190/* To read touch screen channel values */
 191static int mrstouch_nec_adc_read(struct mrstouch_dev *tsdev,
 192                                 u16 *x, u16 *y, u16 *z)
 193{
 194        int err;
 195        u16 xm, ym, zm;
 196
 197        /* configure Y bias for X channels */
 198        err = mrstouch_ts_bias_set(tsdev->asr, MRST_YBIAS);
 199        if (err)
 200                goto ipc_error;
 201
 202        msleep(WAIT_ADC_COMPLETION);
 203
 204        /* read x+ and x- channels */
 205        err = mrstouch_ts_chan_read(tsdev->asr, MRST_TS_CHAN10, x, &xm);
 206        if (err)
 207                goto ipc_error;
 208
 209        /* configure x bias for y channels */
 210        err = mrstouch_ts_bias_set(tsdev->asr, MRST_XBIAS);
 211        if (err)
 212                goto ipc_error;
 213
 214        msleep(WAIT_ADC_COMPLETION);
 215
 216        /* read y+ and y- channels */
 217        err = mrstouch_ts_chan_read(tsdev->asr, MRST_TS_CHAN12, y, &ym);
 218        if (err)
 219                goto ipc_error;
 220
 221        /* configure z bias for x and y channels */
 222        err = mrstouch_ts_bias_set(tsdev->asr, MRST_ZBIAS);
 223        if (err)
 224                goto ipc_error;
 225
 226        msleep(WAIT_ADC_COMPLETION);
 227
 228        /* read z+ and z- channels */
 229        err = mrstouch_ts_chan_read(tsdev->asr, MRST_TS_CHAN10, z, &zm);
 230        if (err)
 231                goto ipc_error;
 232
 233        return 0;
 234
 235ipc_error:
 236        dev_err(tsdev->dev, "ipc error during adc read\n");
 237        return err;
 238}
 239
 240
 241/*************************** Freescale Interface ************************/
 242
 243static int mrstouch_fs_adc_read_prepare(struct mrstouch_dev *tsdev)
 244{
 245        int err, count;
 246        u16 chan;
 247        u16 reg[5];
 248        u8 data[5];
 249
 250        /* Stop the ADC */
 251        err = intel_scu_ipc_update_register(PMIC_REG_MADCINT, 0x00, 0x02);
 252        if (err)
 253                goto ipc_error;
 254
 255        chan = PMICADDR0 + tsdev->asr;
 256
 257        /* Set X BIAS */
 258        for (count = 0; count <= 3; count++) {
 259                reg[count] = chan++;
 260                data[count] = 0x2A;
 261        }
 262        reg[count] =  chan++; /* Dummy */
 263        data[count] = 0;
 264
 265        err = intel_scu_ipc_writev(reg, data, 5);
 266        if (err)
 267                goto ipc_error;
 268
 269        msleep(WAIT_ADC_COMPLETION);
 270
 271        /* Set Y BIAS */
 272        for (count = 0; count <= 3; count++) {
 273                reg[count] = chan++;
 274                data[count] = 0x4A;
 275        }
 276        reg[count] = chan++; /* Dummy */
 277        data[count] = 0;
 278
 279        err = intel_scu_ipc_writev(reg, data, 5);
 280        if (err)
 281                goto ipc_error;
 282
 283        msleep(WAIT_ADC_COMPLETION);
 284
 285        /* Set Z BIAS */
 286        err = intel_scu_ipc_iowrite32(chan + 2, 0x8A8A8A8A);
 287        if (err)
 288                goto ipc_error;
 289
 290        msleep(WAIT_ADC_COMPLETION);
 291
 292        return 0;
 293
 294ipc_error:
 295        dev_err(tsdev->dev, "ipc error during %s\n", __func__);
 296        return err;
 297}
 298
 299static int mrstouch_fs_adc_read(struct mrstouch_dev *tsdev,
 300                                u16 *x, u16 *y, u16 *z)
 301{
 302        int err;
 303        u16 result;
 304        u16 reg[4];
 305        u8 data[4];
 306
 307        result = PMIC_REG_ADCSNS0H + tsdev->asr;
 308
 309        reg[0] = result + 4;
 310        reg[1] = result + 5;
 311        reg[2] = result + 16;
 312        reg[3] = result + 17;
 313
 314        err = intel_scu_ipc_readv(reg, data, 4);
 315        if (err)
 316                goto ipc_error;
 317
 318        *x = data[0] << 3; /* Higher 7 bits */
 319        *x |= data[1] & 0x7; /* Lower 3 bits */
 320        *x &= 0x3FF;
 321
 322        *y = data[2] << 3; /* Higher 7 bits */
 323        *y |= data[3] & 0x7; /* Lower 3 bits */
 324        *y &= 0x3FF;
 325
 326        /* Read Z value */
 327        reg[0] = result + 28;
 328        reg[1] = result + 29;
 329
 330        err = intel_scu_ipc_readv(reg, data, 4);
 331        if (err)
 332                goto ipc_error;
 333
 334        *z = data[0] << 3; /* Higher 7 bits */
 335        *z |= data[1] & 0x7; /* Lower 3 bits */
 336        *z &= 0x3FF;
 337
 338        return 0;
 339
 340ipc_error:
 341        dev_err(tsdev->dev, "ipc error during %s\n", __func__);
 342        return err;
 343}
 344
 345static int mrstouch_fs_adc_read_finish(struct mrstouch_dev *tsdev)
 346{
 347        int err, count;
 348        u16 chan;
 349        u16 reg[5];
 350        u8 data[5];
 351
 352        /* Clear all TS channels */
 353        chan = PMICADDR0 + tsdev->asr;
 354        for (count = 0; count <= 4; count++) {
 355                reg[count] = chan++;
 356                data[count] = 0;
 357        }
 358        err = intel_scu_ipc_writev(reg, data, 5);
 359        if (err)
 360                goto ipc_error;
 361
 362        for (count = 0; count <= 4; count++) {
 363                reg[count] = chan++;
 364                data[count] = 0;
 365        }
 366        err = intel_scu_ipc_writev(reg, data, 5);
 367        if (err)
 368                goto ipc_error;
 369
 370        err = intel_scu_ipc_iowrite32(chan + 2, 0x00000000);
 371        if (err)
 372                goto ipc_error;
 373
 374        /* Start ADC */
 375        err = intel_scu_ipc_update_register(PMIC_REG_MADCINT, 0x02, 0x02);
 376        if (err)
 377                goto ipc_error;
 378
 379        return 0;
 380
 381ipc_error:
 382        dev_err(tsdev->dev, "ipc error during %s\n", __func__);
 383        return err;
 384}
 385
 386static void mrstouch_report_event(struct input_dev *input,
 387                        unsigned int x, unsigned int y, unsigned int z)
 388{
 389        if (z > MRST_PRESSURE_NOMINAL) {
 390                /* Pen touched, report button touch and coordinates */
 391                input_report_key(input, BTN_TOUCH, 1);
 392                input_report_abs(input, ABS_X, x);
 393                input_report_abs(input, ABS_Y, y);
 394        } else {
 395                input_report_key(input, BTN_TOUCH, 0);
 396        }
 397
 398        input_report_abs(input, ABS_PRESSURE, z);
 399        input_sync(input);
 400}
 401
 402/* PENDET interrupt handler */
 403static irqreturn_t mrstouch_pendet_irq(int irq, void *dev_id)
 404{
 405        struct mrstouch_dev *tsdev = dev_id;
 406        u16 x, y, z;
 407
 408        /*
 409         * Should we lower thread priority? Probably not, since we are
 410         * not spinning but sleeping...
 411         */
 412
 413        if (tsdev->read_prepare(tsdev))
 414                goto out;
 415
 416        do {
 417                if (tsdev->read(tsdev, &x, &y, &z))
 418                        break;
 419
 420                mrstouch_report_event(tsdev->input, x, y, z);
 421        } while (z > MRST_PRESSURE_NOMINAL);
 422
 423        tsdev->read_finish(tsdev);
 424
 425out:
 426        return IRQ_HANDLED;
 427}
 428
 429/* Utility to read PMIC ID */
 430static int mrstouch_read_pmic_id(uint *vendor, uint *rev)
 431{
 432        int err;
 433        u8 r;
 434
 435        err = intel_scu_ipc_ioread8(PMIC_REG_ID1, &r);
 436        if (err)
 437                return err;
 438
 439        *vendor = r & 0x7;
 440        *rev = (r >> 3) & 0x7;
 441
 442        return 0;
 443}
 444
 445/*
 446 * Parse ADC channels to find end of the channel configured by other ADC user
 447 * NEC and MAXIM requires 4 channels and FreeScale needs 18 channels
 448 */
 449static int mrstouch_chan_parse(struct mrstouch_dev *tsdev)
 450{
 451        int found = 0;
 452        int err, i;
 453        u8 r8;
 454
 455        for (i = 0; i < MRSTOUCH_MAX_CHANNELS; i++) {
 456                err = intel_scu_ipc_ioread8(PMICADDR0 + i, &r8);
 457                if (err)
 458                        return err;
 459
 460                if (r8 == END_OF_CHANNEL) {
 461                        found = i;
 462                        break;
 463                }
 464        }
 465
 466        if (tsdev->vendor == PMIC_VENDOR_FS) {
 467                if (found > MRSTOUCH_MAX_CHANNELS - 18)
 468                        return -ENOSPC;
 469        } else {
 470                if (found > MRSTOUCH_MAX_CHANNELS - 4)
 471                        return -ENOSPC;
 472        }
 473
 474        return found;
 475}
 476
 477
 478/*
 479 * Writes touch screen channels to ADC address selection registers
 480 */
 481static int mrstouch_ts_chan_set(uint offset)
 482{
 483        u16 chan;
 484
 485        int ret, count;
 486
 487        chan = PMICADDR0 + offset;
 488        for (count = 0; count <= 3; count++) {
 489                ret = intel_scu_ipc_iowrite8(chan++, MRST_TS_CHAN10 + count);
 490                if (ret)
 491                        return ret;
 492        }
 493        return intel_scu_ipc_iowrite8(chan++, END_OF_CHANNEL);
 494}
 495
 496/* Initialize ADC */
 497static int mrstouch_adc_init(struct mrstouch_dev *tsdev)
 498{
 499        int err, start;
 500        u8 ra, rm;
 501
 502        err = mrstouch_read_pmic_id(&tsdev->vendor, &tsdev->rev);
 503        if (err) {
 504                dev_err(tsdev->dev, "Unable to read PMIC id\n");
 505                return err;
 506        }
 507
 508        switch (tsdev->vendor) {
 509        case PMIC_VENDOR_NEC:
 510        case PMIC_VENDOR_MAXIM:
 511                tsdev->read_prepare = mrstouch_nec_adc_read_prepare;
 512                tsdev->read = mrstouch_nec_adc_read;
 513                tsdev->read_finish = mrstouch_nec_adc_read_finish;
 514                break;
 515
 516        case PMIC_VENDOR_FS:
 517                tsdev->read_prepare = mrstouch_fs_adc_read_prepare;
 518                tsdev->read = mrstouch_fs_adc_read;
 519                tsdev->read_finish = mrstouch_fs_adc_read_finish;
 520                break;
 521
 522        default:
 523                dev_err(tsdev->dev,
 524                        "Unsupported touchscreen: %d\n", tsdev->vendor);
 525                return -ENXIO;
 526        }
 527
 528        start = mrstouch_chan_parse(tsdev);
 529        if (start < 0) {
 530                dev_err(tsdev->dev, "Unable to parse channels\n");
 531                return start;
 532        }
 533
 534        tsdev->asr = start;
 535
 536        /*
 537         * ADC power on, start, enable PENDET and set loop delay
 538         * ADC loop delay is set to 4.5 ms approximately
 539         * Loop delay more than this results in jitter in adc readings
 540         * Setting loop delay to 0 (continuous loop) in MAXIM stops PENDET
 541         * interrupt generation sometimes.
 542         */
 543
 544        if (tsdev->vendor == PMIC_VENDOR_FS) {
 545                ra = 0xE0 | ADC_LOOP_DELAY0;
 546                rm = 0x5;
 547        } else {
 548                /* NEC and MAXIm not consistent with loop delay 0 */
 549                ra = 0xE0 | ADC_LOOP_DELAY1;
 550                rm = 0x0;
 551
 552                /* configure touch screen channels */
 553                err = mrstouch_ts_chan_set(tsdev->asr);
 554                if (err)
 555                        return err;
 556        }
 557
 558        err = intel_scu_ipc_update_register(PMIC_REG_ADCCNTL1, ra, 0xE7);
 559        if (err)
 560                return err;
 561
 562        err = intel_scu_ipc_update_register(PMIC_REG_MADCINT, rm, 0x03);
 563        if (err)
 564                return err;
 565
 566        return 0;
 567}
 568
 569
 570/* Probe function for touch screen driver */
 571static int mrstouch_probe(struct platform_device *pdev)
 572{
 573        struct mrstouch_dev *tsdev;
 574        struct input_dev *input;
 575        int err;
 576        int irq;
 577
 578        irq = platform_get_irq(pdev, 0);
 579        if (irq < 0) {
 580                dev_err(&pdev->dev, "no interrupt assigned\n");
 581                return -EINVAL;
 582        }
 583
 584        tsdev = kzalloc(sizeof(struct mrstouch_dev), GFP_KERNEL);
 585        input = input_allocate_device();
 586        if (!tsdev || !input) {
 587                dev_err(&pdev->dev, "unable to allocate memory\n");
 588                err = -ENOMEM;
 589                goto err_free_mem;
 590        }
 591
 592        tsdev->dev = &pdev->dev;
 593        tsdev->input = input;
 594        tsdev->irq = irq;
 595
 596        snprintf(tsdev->phys, sizeof(tsdev->phys),
 597                 "%s/input0", dev_name(tsdev->dev));
 598
 599        err = mrstouch_adc_init(tsdev);
 600        if (err) {
 601                dev_err(&pdev->dev, "ADC initialization failed\n");
 602                goto err_free_mem;
 603        }
 604
 605        input->name = "mrst_touchscreen";
 606        input->phys = tsdev->phys;
 607        input->dev.parent = tsdev->dev;
 608
 609        input->id.vendor = tsdev->vendor;
 610        input->id.version = tsdev->rev;
 611
 612        input->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
 613        input->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
 614
 615        input_set_abs_params(tsdev->input, ABS_X,
 616                             MRST_X_MIN, MRST_X_MAX, MRST_X_FUZZ, 0);
 617        input_set_abs_params(tsdev->input, ABS_Y,
 618                             MRST_Y_MIN, MRST_Y_MAX, MRST_Y_FUZZ, 0);
 619        input_set_abs_params(tsdev->input, ABS_PRESSURE,
 620                             MRST_PRESSURE_MIN, MRST_PRESSURE_MAX, 0, 0);
 621
 622        err = request_threaded_irq(tsdev->irq, NULL, mrstouch_pendet_irq,
 623                                   IRQF_ONESHOT, "mrstouch", tsdev);
 624        if (err) {
 625                dev_err(tsdev->dev, "unable to allocate irq\n");
 626                goto err_free_mem;
 627        }
 628
 629        err = input_register_device(tsdev->input);
 630        if (err) {
 631                dev_err(tsdev->dev, "unable to register input device\n");
 632                goto err_free_irq;
 633        }
 634
 635        platform_set_drvdata(pdev, tsdev);
 636        return 0;
 637
 638err_free_irq:
 639        free_irq(tsdev->irq, tsdev);
 640err_free_mem:
 641        input_free_device(input);
 642        kfree(tsdev);
 643        return err;
 644}
 645
 646static int mrstouch_remove(struct platform_device *pdev)
 647{
 648        struct mrstouch_dev *tsdev = platform_get_drvdata(pdev);
 649
 650        free_irq(tsdev->irq, tsdev);
 651        input_unregister_device(tsdev->input);
 652        kfree(tsdev);
 653
 654        return 0;
 655}
 656
 657static struct platform_driver mrstouch_driver = {
 658        .driver = {
 659                .name   = "pmic_touch",
 660                .owner  = THIS_MODULE,
 661        },
 662        .probe          = mrstouch_probe,
 663        .remove         = mrstouch_remove,
 664};
 665module_platform_driver(mrstouch_driver);
 666
 667MODULE_AUTHOR("Sreedhara Murthy. D.S, sreedhara.ds@intel.com");
 668MODULE_DESCRIPTION("Intel Moorestown Resistive Touch Screen Driver");
 669MODULE_LICENSE("GPL");
 670