linux/drivers/input/mouse/trackpoint.c
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   1/*
   2 * Stephen Evanchik <evanchsa@gmail.com>
   3 *
   4 * This program is free software; you can redistribute it and/or modify it
   5 * under the terms of the GNU General Public License version 2 as published by
   6 * the Free Software Foundation.
   7 *
   8 * Trademarks are the property of their respective owners.
   9 */
  10
  11#include <linux/slab.h>
  12#include <linux/delay.h>
  13#include <linux/serio.h>
  14#include <linux/module.h>
  15#include <linux/input.h>
  16#include <linux/libps2.h>
  17#include <linux/proc_fs.h>
  18#include <linux/uaccess.h>
  19#include "psmouse.h"
  20#include "trackpoint.h"
  21
  22static const char * const trackpoint_variants[] = {
  23        [TP_VARIANT_IBM]        = "IBM",
  24        [TP_VARIANT_ALPS]       = "ALPS",
  25        [TP_VARIANT_ELAN]       = "Elan",
  26        [TP_VARIANT_NXP]        = "NXP",
  27};
  28
  29/*
  30 * Power-on Reset: Resets all trackpoint parameters, including RAM values,
  31 * to defaults.
  32 * Returns zero on success, non-zero on failure.
  33 */
  34static int trackpoint_power_on_reset(struct ps2dev *ps2dev)
  35{
  36        u8 param[2] = { TP_POR };
  37        int err;
  38
  39        err = ps2_command(ps2dev, param, MAKE_PS2_CMD(1, 2, TP_COMMAND));
  40        if (err)
  41                return err;
  42
  43        /* Check for success response -- 0xAA00 */
  44        if (param[0] != 0xAA || param[1] != 0x00)
  45                return -ENODEV;
  46
  47        return 0;
  48}
  49
  50/*
  51 * Device IO: read, write and toggle bit
  52 */
  53static int trackpoint_read(struct ps2dev *ps2dev, u8 loc, u8 *results)
  54{
  55        results[0] = loc;
  56
  57        return ps2_command(ps2dev, results, MAKE_PS2_CMD(1, 1, TP_COMMAND));
  58}
  59
  60static int trackpoint_write(struct ps2dev *ps2dev, u8 loc, u8 val)
  61{
  62        u8 param[3] = { TP_WRITE_MEM, loc, val };
  63
  64        return ps2_command(ps2dev, param, MAKE_PS2_CMD(3, 0, TP_COMMAND));
  65}
  66
  67static int trackpoint_toggle_bit(struct ps2dev *ps2dev, u8 loc, u8 mask)
  68{
  69        u8 param[3] = { TP_TOGGLE, loc, mask };
  70
  71        /* Bad things will happen if the loc param isn't in this range */
  72        if (loc < 0x20 || loc >= 0x2F)
  73                return -EINVAL;
  74
  75        return ps2_command(ps2dev, param, MAKE_PS2_CMD(3, 0, TP_COMMAND));
  76}
  77
  78static int trackpoint_update_bit(struct ps2dev *ps2dev,
  79                                 u8 loc, u8 mask, u8 value)
  80{
  81        int retval;
  82        u8 data;
  83
  84        retval = trackpoint_read(ps2dev, loc, &data);
  85        if (retval)
  86                return retval;
  87
  88        if (((data & mask) == mask) != !!value)
  89                retval = trackpoint_toggle_bit(ps2dev, loc, mask);
  90
  91        return retval;
  92}
  93
  94/*
  95 * Trackpoint-specific attributes
  96 */
  97struct trackpoint_attr_data {
  98        size_t field_offset;
  99        u8 command;
 100        u8 mask;
 101        bool inverted;
 102        u8 power_on_default;
 103};
 104
 105static ssize_t trackpoint_show_int_attr(struct psmouse *psmouse,
 106                                        void *data, char *buf)
 107{
 108        struct trackpoint_data *tp = psmouse->private;
 109        struct trackpoint_attr_data *attr = data;
 110        u8 value = *(u8 *)((void *)tp + attr->field_offset);
 111
 112        if (attr->inverted)
 113                value = !value;
 114
 115        return sprintf(buf, "%u\n", value);
 116}
 117
 118static ssize_t trackpoint_set_int_attr(struct psmouse *psmouse, void *data,
 119                                        const char *buf, size_t count)
 120{
 121        struct trackpoint_data *tp = psmouse->private;
 122        struct trackpoint_attr_data *attr = data;
 123        u8 *field = (void *)tp + attr->field_offset;
 124        u8 value;
 125        int err;
 126
 127        err = kstrtou8(buf, 10, &value);
 128        if (err)
 129                return err;
 130
 131        *field = value;
 132        err = trackpoint_write(&psmouse->ps2dev, attr->command, value);
 133
 134        return err ?: count;
 135}
 136
 137#define TRACKPOINT_INT_ATTR(_name, _command, _default)                          \
 138        static struct trackpoint_attr_data trackpoint_attr_##_name = {          \
 139                .field_offset = offsetof(struct trackpoint_data, _name),        \
 140                .command = _command,                                            \
 141                .power_on_default = _default,                                   \
 142        };                                                                      \
 143        PSMOUSE_DEFINE_ATTR(_name, S_IWUSR | S_IRUGO,                           \
 144                            &trackpoint_attr_##_name,                           \
 145                            trackpoint_show_int_attr, trackpoint_set_int_attr)
 146
 147static ssize_t trackpoint_set_bit_attr(struct psmouse *psmouse, void *data,
 148                                        const char *buf, size_t count)
 149{
 150        struct trackpoint_data *tp = psmouse->private;
 151        struct trackpoint_attr_data *attr = data;
 152        bool *field = (void *)tp + attr->field_offset;
 153        bool value;
 154        int err;
 155
 156        err = kstrtobool(buf, &value);
 157        if (err)
 158                return err;
 159
 160        if (attr->inverted)
 161                value = !value;
 162
 163        if (*field != value) {
 164                *field = value;
 165                err = trackpoint_toggle_bit(&psmouse->ps2dev,
 166                                            attr->command, attr->mask);
 167        }
 168
 169        return err ?: count;
 170}
 171
 172
 173#define TRACKPOINT_BIT_ATTR(_name, _command, _mask, _inv, _default)     \
 174static struct trackpoint_attr_data trackpoint_attr_##_name = {          \
 175        .field_offset           = offsetof(struct trackpoint_data,      \
 176                                           _name),                      \
 177        .command                = _command,                             \
 178        .mask                   = _mask,                                \
 179        .inverted               = _inv,                                 \
 180        .power_on_default       = _default,                             \
 181        };                                                              \
 182PSMOUSE_DEFINE_ATTR(_name, S_IWUSR | S_IRUGO,                           \
 183                    &trackpoint_attr_##_name,                           \
 184                    trackpoint_show_int_attr, trackpoint_set_bit_attr)
 185
 186TRACKPOINT_INT_ATTR(sensitivity, TP_SENS, TP_DEF_SENS);
 187TRACKPOINT_INT_ATTR(speed, TP_SPEED, TP_DEF_SPEED);
 188TRACKPOINT_INT_ATTR(inertia, TP_INERTIA, TP_DEF_INERTIA);
 189TRACKPOINT_INT_ATTR(reach, TP_REACH, TP_DEF_REACH);
 190TRACKPOINT_INT_ATTR(draghys, TP_DRAGHYS, TP_DEF_DRAGHYS);
 191TRACKPOINT_INT_ATTR(mindrag, TP_MINDRAG, TP_DEF_MINDRAG);
 192TRACKPOINT_INT_ATTR(thresh, TP_THRESH, TP_DEF_THRESH);
 193TRACKPOINT_INT_ATTR(upthresh, TP_UP_THRESH, TP_DEF_UP_THRESH);
 194TRACKPOINT_INT_ATTR(ztime, TP_Z_TIME, TP_DEF_Z_TIME);
 195TRACKPOINT_INT_ATTR(jenks, TP_JENKS_CURV, TP_DEF_JENKS_CURV);
 196TRACKPOINT_INT_ATTR(drift_time, TP_DRIFT_TIME, TP_DEF_DRIFT_TIME);
 197
 198TRACKPOINT_BIT_ATTR(press_to_select, TP_TOGGLE_PTSON, TP_MASK_PTSON, false,
 199                    TP_DEF_PTSON);
 200TRACKPOINT_BIT_ATTR(skipback, TP_TOGGLE_SKIPBACK, TP_MASK_SKIPBACK, false,
 201                    TP_DEF_SKIPBACK);
 202TRACKPOINT_BIT_ATTR(ext_dev, TP_TOGGLE_EXT_DEV, TP_MASK_EXT_DEV, true,
 203                    TP_DEF_EXT_DEV);
 204
 205static bool trackpoint_is_attr_available(struct psmouse *psmouse,
 206                                         struct attribute *attr)
 207{
 208        struct trackpoint_data *tp = psmouse->private;
 209
 210        return tp->variant_id == TP_VARIANT_IBM ||
 211                attr == &psmouse_attr_sensitivity.dattr.attr ||
 212                attr == &psmouse_attr_press_to_select.dattr.attr;
 213}
 214
 215static umode_t trackpoint_is_attr_visible(struct kobject *kobj,
 216                                          struct attribute *attr, int n)
 217{
 218        struct device *dev = container_of(kobj, struct device, kobj);
 219        struct serio *serio = to_serio_port(dev);
 220        struct psmouse *psmouse = serio_get_drvdata(serio);
 221
 222        return trackpoint_is_attr_available(psmouse, attr) ? attr->mode : 0;
 223}
 224
 225static struct attribute *trackpoint_attrs[] = {
 226        &psmouse_attr_sensitivity.dattr.attr,
 227        &psmouse_attr_speed.dattr.attr,
 228        &psmouse_attr_inertia.dattr.attr,
 229        &psmouse_attr_reach.dattr.attr,
 230        &psmouse_attr_draghys.dattr.attr,
 231        &psmouse_attr_mindrag.dattr.attr,
 232        &psmouse_attr_thresh.dattr.attr,
 233        &psmouse_attr_upthresh.dattr.attr,
 234        &psmouse_attr_ztime.dattr.attr,
 235        &psmouse_attr_jenks.dattr.attr,
 236        &psmouse_attr_drift_time.dattr.attr,
 237        &psmouse_attr_press_to_select.dattr.attr,
 238        &psmouse_attr_skipback.dattr.attr,
 239        &psmouse_attr_ext_dev.dattr.attr,
 240        NULL
 241};
 242
 243static struct attribute_group trackpoint_attr_group = {
 244        .is_visible     = trackpoint_is_attr_visible,
 245        .attrs          = trackpoint_attrs,
 246};
 247
 248#define TRACKPOINT_UPDATE(_power_on, _psmouse, _tp, _name)              \
 249do {                                                                    \
 250        struct trackpoint_attr_data *_attr = &trackpoint_attr_##_name;  \
 251                                                                        \
 252        if ((!_power_on || _tp->_name != _attr->power_on_default) &&    \
 253            trackpoint_is_attr_available(_psmouse,                      \
 254                                &psmouse_attr_##_name.dattr.attr)) {    \
 255                if (!_attr->mask)                                       \
 256                        trackpoint_write(&_psmouse->ps2dev,             \
 257                                         _attr->command, _tp->_name);   \
 258                else                                                    \
 259                        trackpoint_update_bit(&_psmouse->ps2dev,        \
 260                                        _attr->command, _attr->mask,    \
 261                                        _tp->_name);                    \
 262        }                                                               \
 263} while (0)
 264
 265#define TRACKPOINT_SET_POWER_ON_DEFAULT(_tp, _name)                     \
 266do {                                                                    \
 267        _tp->_name = trackpoint_attr_##_name.power_on_default;          \
 268} while (0)
 269
 270static int trackpoint_start_protocol(struct psmouse *psmouse,
 271                                     u8 *variant_id, u8 *firmware_id)
 272{
 273        u8 param[2] = { 0 };
 274        int error;
 275
 276        error = ps2_command(&psmouse->ps2dev,
 277                            param, MAKE_PS2_CMD(0, 2, TP_READ_ID));
 278        if (error)
 279                return error;
 280
 281        switch (param[0]) {
 282        case TP_VARIANT_IBM:
 283        case TP_VARIANT_ALPS:
 284        case TP_VARIANT_ELAN:
 285        case TP_VARIANT_NXP:
 286                if (variant_id)
 287                        *variant_id = param[0];
 288                if (firmware_id)
 289                        *firmware_id = param[1];
 290                return 0;
 291        }
 292
 293        return -ENODEV;
 294}
 295
 296/*
 297 * Write parameters to trackpad.
 298 * in_power_on_state: Set to true if TP is in default / power-on state (ex. if
 299 *                    power-on reset was run). If so, values will only be
 300 *                    written to TP if they differ from power-on default.
 301 */
 302static int trackpoint_sync(struct psmouse *psmouse, bool in_power_on_state)
 303{
 304        struct trackpoint_data *tp = psmouse->private;
 305
 306        if (!in_power_on_state && tp->variant_id == TP_VARIANT_IBM) {
 307                /*
 308                 * Disable features that may make device unusable
 309                 * with this driver.
 310                 */
 311                trackpoint_update_bit(&psmouse->ps2dev, TP_TOGGLE_TWOHAND,
 312                                      TP_MASK_TWOHAND, TP_DEF_TWOHAND);
 313
 314                trackpoint_update_bit(&psmouse->ps2dev, TP_TOGGLE_SOURCE_TAG,
 315                                      TP_MASK_SOURCE_TAG, TP_DEF_SOURCE_TAG);
 316
 317                trackpoint_update_bit(&psmouse->ps2dev, TP_TOGGLE_MB,
 318                                      TP_MASK_MB, TP_DEF_MB);
 319        }
 320
 321        /*
 322         * These properties can be changed in this driver. Only
 323         * configure them if the values are non-default or if the TP is in
 324         * an unknown state.
 325         */
 326        TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, sensitivity);
 327        TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, inertia);
 328        TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, speed);
 329        TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, reach);
 330        TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, draghys);
 331        TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, mindrag);
 332        TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, thresh);
 333        TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, upthresh);
 334        TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, ztime);
 335        TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, jenks);
 336        TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, drift_time);
 337
 338        /* toggles */
 339        TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, press_to_select);
 340        TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, skipback);
 341        TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, ext_dev);
 342
 343        return 0;
 344}
 345
 346static void trackpoint_defaults(struct trackpoint_data *tp)
 347{
 348        TRACKPOINT_SET_POWER_ON_DEFAULT(tp, sensitivity);
 349        TRACKPOINT_SET_POWER_ON_DEFAULT(tp, speed);
 350        TRACKPOINT_SET_POWER_ON_DEFAULT(tp, reach);
 351        TRACKPOINT_SET_POWER_ON_DEFAULT(tp, draghys);
 352        TRACKPOINT_SET_POWER_ON_DEFAULT(tp, mindrag);
 353        TRACKPOINT_SET_POWER_ON_DEFAULT(tp, thresh);
 354        TRACKPOINT_SET_POWER_ON_DEFAULT(tp, upthresh);
 355        TRACKPOINT_SET_POWER_ON_DEFAULT(tp, ztime);
 356        TRACKPOINT_SET_POWER_ON_DEFAULT(tp, jenks);
 357        TRACKPOINT_SET_POWER_ON_DEFAULT(tp, drift_time);
 358        TRACKPOINT_SET_POWER_ON_DEFAULT(tp, inertia);
 359
 360        /* toggles */
 361        TRACKPOINT_SET_POWER_ON_DEFAULT(tp, press_to_select);
 362        TRACKPOINT_SET_POWER_ON_DEFAULT(tp, skipback);
 363        TRACKPOINT_SET_POWER_ON_DEFAULT(tp, ext_dev);
 364}
 365
 366static void trackpoint_disconnect(struct psmouse *psmouse)
 367{
 368        device_remove_group(&psmouse->ps2dev.serio->dev,
 369                            &trackpoint_attr_group);
 370
 371        kfree(psmouse->private);
 372        psmouse->private = NULL;
 373}
 374
 375static int trackpoint_reconnect(struct psmouse *psmouse)
 376{
 377        struct trackpoint_data *tp = psmouse->private;
 378        int error;
 379        bool was_reset;
 380
 381        error = trackpoint_start_protocol(psmouse, NULL, NULL);
 382        if (error)
 383                return error;
 384
 385        was_reset = tp->variant_id == TP_VARIANT_IBM &&
 386                    trackpoint_power_on_reset(&psmouse->ps2dev) == 0;
 387
 388        error = trackpoint_sync(psmouse, was_reset);
 389        if (error)
 390                return error;
 391
 392        return 0;
 393}
 394
 395int trackpoint_detect(struct psmouse *psmouse, bool set_properties)
 396{
 397        struct ps2dev *ps2dev = &psmouse->ps2dev;
 398        struct trackpoint_data *tp;
 399        u8 variant_id;
 400        u8 firmware_id;
 401        u8 button_info;
 402        int error;
 403
 404        error = trackpoint_start_protocol(psmouse, &variant_id, &firmware_id);
 405        if (error)
 406                return error;
 407
 408        if (!set_properties)
 409                return 0;
 410
 411        tp = kzalloc(sizeof(*tp), GFP_KERNEL);
 412        if (!tp)
 413                return -ENOMEM;
 414
 415        trackpoint_defaults(tp);
 416        tp->variant_id = variant_id;
 417        tp->firmware_id = firmware_id;
 418
 419        psmouse->private = tp;
 420
 421        psmouse->vendor = trackpoint_variants[variant_id];
 422        psmouse->name = "TrackPoint";
 423
 424        psmouse->reconnect = trackpoint_reconnect;
 425        psmouse->disconnect = trackpoint_disconnect;
 426
 427        if (variant_id != TP_VARIANT_IBM) {
 428                /* Newer variants do not support extended button query. */
 429                button_info = 0x33;
 430        } else {
 431                error = trackpoint_read(ps2dev, TP_EXT_BTN, &button_info);
 432                if (error) {
 433                        psmouse_warn(psmouse,
 434                                     "failed to get extended button data, assuming 3 buttons\n");
 435                        button_info = 0x33;
 436                } else if (!button_info) {
 437                        psmouse_warn(psmouse,
 438                                     "got 0 in extended button data, assuming 3 buttons\n");
 439                        button_info = 0x33;
 440                }
 441        }
 442
 443        if ((button_info & 0x0f) >= 3)
 444                input_set_capability(psmouse->dev, EV_KEY, BTN_MIDDLE);
 445
 446        __set_bit(INPUT_PROP_POINTER, psmouse->dev->propbit);
 447        __set_bit(INPUT_PROP_POINTING_STICK, psmouse->dev->propbit);
 448
 449        if (variant_id != TP_VARIANT_IBM ||
 450            trackpoint_power_on_reset(ps2dev) != 0) {
 451                /*
 452                 * Write defaults to TP if we did not reset the trackpoint.
 453                 */
 454                trackpoint_sync(psmouse, false);
 455        }
 456
 457        error = device_add_group(&ps2dev->serio->dev, &trackpoint_attr_group);
 458        if (error) {
 459                psmouse_err(psmouse,
 460                            "failed to create sysfs attributes, error: %d\n",
 461                            error);
 462                kfree(psmouse->private);
 463                psmouse->private = NULL;
 464                return -1;
 465        }
 466
 467        psmouse_info(psmouse,
 468                     "%s TrackPoint firmware: 0x%02x, buttons: %d/%d\n",
 469                     psmouse->vendor, firmware_id,
 470                     (button_info & 0xf0) >> 4, button_info & 0x0f);
 471
 472        return 0;
 473}
 474
 475