linux/drivers/input/mouse/trackpoint.c
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   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * Stephen Evanchik <evanchsa@gmail.com>
   4 *
   5 * Trademarks are the property of their respective owners.
   6 */
   7
   8#include <linux/slab.h>
   9#include <linux/delay.h>
  10#include <linux/serio.h>
  11#include <linux/module.h>
  12#include <linux/input.h>
  13#include <linux/libps2.h>
  14#include <linux/proc_fs.h>
  15#include <linux/uaccess.h>
  16#include "psmouse.h"
  17#include "trackpoint.h"
  18
  19static const char * const trackpoint_variants[] = {
  20        [TP_VARIANT_IBM]                = "IBM",
  21        [TP_VARIANT_ALPS]               = "ALPS",
  22        [TP_VARIANT_ELAN]               = "Elan",
  23        [TP_VARIANT_NXP]                = "NXP",
  24        [TP_VARIANT_JYT_SYNAPTICS]      = "JYT_Synaptics",
  25        [TP_VARIANT_SYNAPTICS]          = "Synaptics",
  26};
  27
  28/*
  29 * Power-on Reset: Resets all trackpoint parameters, including RAM values,
  30 * to defaults.
  31 * Returns zero on success, non-zero on failure.
  32 */
  33static int trackpoint_power_on_reset(struct ps2dev *ps2dev)
  34{
  35        u8 param[2] = { TP_POR };
  36        int err;
  37
  38        err = ps2_command(ps2dev, param, MAKE_PS2_CMD(1, 2, TP_COMMAND));
  39        if (err)
  40                return err;
  41
  42        /* Check for success response -- 0xAA00 */
  43        if (param[0] != 0xAA || param[1] != 0x00)
  44                return -ENODEV;
  45
  46        return 0;
  47}
  48
  49/*
  50 * Device IO: read, write and toggle bit
  51 */
  52static int trackpoint_read(struct ps2dev *ps2dev, u8 loc, u8 *results)
  53{
  54        results[0] = loc;
  55
  56        return ps2_command(ps2dev, results, MAKE_PS2_CMD(1, 1, TP_COMMAND));
  57}
  58
  59static int trackpoint_write(struct ps2dev *ps2dev, u8 loc, u8 val)
  60{
  61        u8 param[3] = { TP_WRITE_MEM, loc, val };
  62
  63        return ps2_command(ps2dev, param, MAKE_PS2_CMD(3, 0, TP_COMMAND));
  64}
  65
  66static int trackpoint_toggle_bit(struct ps2dev *ps2dev, u8 loc, u8 mask)
  67{
  68        u8 param[3] = { TP_TOGGLE, loc, mask };
  69
  70        /* Bad things will happen if the loc param isn't in this range */
  71        if (loc < 0x20 || loc >= 0x2F)
  72                return -EINVAL;
  73
  74        return ps2_command(ps2dev, param, MAKE_PS2_CMD(3, 0, TP_COMMAND));
  75}
  76
  77static int trackpoint_update_bit(struct ps2dev *ps2dev,
  78                                 u8 loc, u8 mask, u8 value)
  79{
  80        int retval;
  81        u8 data;
  82
  83        retval = trackpoint_read(ps2dev, loc, &data);
  84        if (retval)
  85                return retval;
  86
  87        if (((data & mask) == mask) != !!value)
  88                retval = trackpoint_toggle_bit(ps2dev, loc, mask);
  89
  90        return retval;
  91}
  92
  93/*
  94 * Trackpoint-specific attributes
  95 */
  96struct trackpoint_attr_data {
  97        size_t field_offset;
  98        u8 command;
  99        u8 mask;
 100        bool inverted;
 101        u8 power_on_default;
 102};
 103
 104static ssize_t trackpoint_show_int_attr(struct psmouse *psmouse,
 105                                        void *data, char *buf)
 106{
 107        struct trackpoint_data *tp = psmouse->private;
 108        struct trackpoint_attr_data *attr = data;
 109        u8 value = *(u8 *)((void *)tp + attr->field_offset);
 110
 111        if (attr->inverted)
 112                value = !value;
 113
 114        return sprintf(buf, "%u\n", value);
 115}
 116
 117static ssize_t trackpoint_set_int_attr(struct psmouse *psmouse, void *data,
 118                                        const char *buf, size_t count)
 119{
 120        struct trackpoint_data *tp = psmouse->private;
 121        struct trackpoint_attr_data *attr = data;
 122        u8 *field = (void *)tp + attr->field_offset;
 123        u8 value;
 124        int err;
 125
 126        err = kstrtou8(buf, 10, &value);
 127        if (err)
 128                return err;
 129
 130        *field = value;
 131        err = trackpoint_write(&psmouse->ps2dev, attr->command, value);
 132
 133        return err ?: count;
 134}
 135
 136#define TRACKPOINT_INT_ATTR(_name, _command, _default)                          \
 137        static struct trackpoint_attr_data trackpoint_attr_##_name = {          \
 138                .field_offset = offsetof(struct trackpoint_data, _name),        \
 139                .command = _command,                                            \
 140                .power_on_default = _default,                                   \
 141        };                                                                      \
 142        PSMOUSE_DEFINE_ATTR(_name, S_IWUSR | S_IRUGO,                           \
 143                            &trackpoint_attr_##_name,                           \
 144                            trackpoint_show_int_attr, trackpoint_set_int_attr)
 145
 146static ssize_t trackpoint_set_bit_attr(struct psmouse *psmouse, void *data,
 147                                        const char *buf, size_t count)
 148{
 149        struct trackpoint_data *tp = psmouse->private;
 150        struct trackpoint_attr_data *attr = data;
 151        bool *field = (void *)tp + attr->field_offset;
 152        bool value;
 153        int err;
 154
 155        err = kstrtobool(buf, &value);
 156        if (err)
 157                return err;
 158
 159        if (attr->inverted)
 160                value = !value;
 161
 162        if (*field != value) {
 163                *field = value;
 164                err = trackpoint_toggle_bit(&psmouse->ps2dev,
 165                                            attr->command, attr->mask);
 166        }
 167
 168        return err ?: count;
 169}
 170
 171
 172#define TRACKPOINT_BIT_ATTR(_name, _command, _mask, _inv, _default)     \
 173static struct trackpoint_attr_data trackpoint_attr_##_name = {          \
 174        .field_offset           = offsetof(struct trackpoint_data,      \
 175                                           _name),                      \
 176        .command                = _command,                             \
 177        .mask                   = _mask,                                \
 178        .inverted               = _inv,                                 \
 179        .power_on_default       = _default,                             \
 180        };                                                              \
 181PSMOUSE_DEFINE_ATTR(_name, S_IWUSR | S_IRUGO,                           \
 182                    &trackpoint_attr_##_name,                           \
 183                    trackpoint_show_int_attr, trackpoint_set_bit_attr)
 184
 185TRACKPOINT_INT_ATTR(sensitivity, TP_SENS, TP_DEF_SENS);
 186TRACKPOINT_INT_ATTR(speed, TP_SPEED, TP_DEF_SPEED);
 187TRACKPOINT_INT_ATTR(inertia, TP_INERTIA, TP_DEF_INERTIA);
 188TRACKPOINT_INT_ATTR(reach, TP_REACH, TP_DEF_REACH);
 189TRACKPOINT_INT_ATTR(draghys, TP_DRAGHYS, TP_DEF_DRAGHYS);
 190TRACKPOINT_INT_ATTR(mindrag, TP_MINDRAG, TP_DEF_MINDRAG);
 191TRACKPOINT_INT_ATTR(thresh, TP_THRESH, TP_DEF_THRESH);
 192TRACKPOINT_INT_ATTR(upthresh, TP_UP_THRESH, TP_DEF_UP_THRESH);
 193TRACKPOINT_INT_ATTR(ztime, TP_Z_TIME, TP_DEF_Z_TIME);
 194TRACKPOINT_INT_ATTR(jenks, TP_JENKS_CURV, TP_DEF_JENKS_CURV);
 195TRACKPOINT_INT_ATTR(drift_time, TP_DRIFT_TIME, TP_DEF_DRIFT_TIME);
 196
 197TRACKPOINT_BIT_ATTR(press_to_select, TP_TOGGLE_PTSON, TP_MASK_PTSON, false,
 198                    TP_DEF_PTSON);
 199TRACKPOINT_BIT_ATTR(skipback, TP_TOGGLE_SKIPBACK, TP_MASK_SKIPBACK, false,
 200                    TP_DEF_SKIPBACK);
 201TRACKPOINT_BIT_ATTR(ext_dev, TP_TOGGLE_EXT_DEV, TP_MASK_EXT_DEV, true,
 202                    TP_DEF_EXT_DEV);
 203
 204static bool trackpoint_is_attr_available(struct psmouse *psmouse,
 205                                         struct attribute *attr)
 206{
 207        struct trackpoint_data *tp = psmouse->private;
 208
 209        return tp->variant_id == TP_VARIANT_IBM ||
 210                attr == &psmouse_attr_sensitivity.dattr.attr ||
 211                attr == &psmouse_attr_press_to_select.dattr.attr;
 212}
 213
 214static umode_t trackpoint_is_attr_visible(struct kobject *kobj,
 215                                          struct attribute *attr, int n)
 216{
 217        struct device *dev = kobj_to_dev(kobj);
 218        struct serio *serio = to_serio_port(dev);
 219        struct psmouse *psmouse = serio_get_drvdata(serio);
 220
 221        return trackpoint_is_attr_available(psmouse, attr) ? attr->mode : 0;
 222}
 223
 224static struct attribute *trackpoint_attrs[] = {
 225        &psmouse_attr_sensitivity.dattr.attr,
 226        &psmouse_attr_speed.dattr.attr,
 227        &psmouse_attr_inertia.dattr.attr,
 228        &psmouse_attr_reach.dattr.attr,
 229        &psmouse_attr_draghys.dattr.attr,
 230        &psmouse_attr_mindrag.dattr.attr,
 231        &psmouse_attr_thresh.dattr.attr,
 232        &psmouse_attr_upthresh.dattr.attr,
 233        &psmouse_attr_ztime.dattr.attr,
 234        &psmouse_attr_jenks.dattr.attr,
 235        &psmouse_attr_drift_time.dattr.attr,
 236        &psmouse_attr_press_to_select.dattr.attr,
 237        &psmouse_attr_skipback.dattr.attr,
 238        &psmouse_attr_ext_dev.dattr.attr,
 239        NULL
 240};
 241
 242static struct attribute_group trackpoint_attr_group = {
 243        .is_visible     = trackpoint_is_attr_visible,
 244        .attrs          = trackpoint_attrs,
 245};
 246
 247#define TRACKPOINT_UPDATE(_power_on, _psmouse, _tp, _name)              \
 248do {                                                                    \
 249        struct trackpoint_attr_data *_attr = &trackpoint_attr_##_name;  \
 250                                                                        \
 251        if ((!_power_on || _tp->_name != _attr->power_on_default) &&    \
 252            trackpoint_is_attr_available(_psmouse,                      \
 253                                &psmouse_attr_##_name.dattr.attr)) {    \
 254                if (!_attr->mask)                                       \
 255                        trackpoint_write(&_psmouse->ps2dev,             \
 256                                         _attr->command, _tp->_name);   \
 257                else                                                    \
 258                        trackpoint_update_bit(&_psmouse->ps2dev,        \
 259                                        _attr->command, _attr->mask,    \
 260                                        _tp->_name);                    \
 261        }                                                               \
 262} while (0)
 263
 264#define TRACKPOINT_SET_POWER_ON_DEFAULT(_tp, _name)                     \
 265do {                                                                    \
 266        _tp->_name = trackpoint_attr_##_name.power_on_default;          \
 267} while (0)
 268
 269static int trackpoint_start_protocol(struct psmouse *psmouse,
 270                                     u8 *variant_id, u8 *firmware_id)
 271{
 272        u8 param[2] = { 0 };
 273        int error;
 274
 275        error = ps2_command(&psmouse->ps2dev,
 276                            param, MAKE_PS2_CMD(0, 2, TP_READ_ID));
 277        if (error)
 278                return error;
 279
 280        switch (param[0]) {
 281        case TP_VARIANT_IBM:
 282        case TP_VARIANT_ALPS:
 283        case TP_VARIANT_ELAN:
 284        case TP_VARIANT_NXP:
 285        case TP_VARIANT_JYT_SYNAPTICS:
 286        case TP_VARIANT_SYNAPTICS:
 287                if (variant_id)
 288                        *variant_id = param[0];
 289                if (firmware_id)
 290                        *firmware_id = param[1];
 291                return 0;
 292        }
 293
 294        return -ENODEV;
 295}
 296
 297/*
 298 * Write parameters to trackpad.
 299 * in_power_on_state: Set to true if TP is in default / power-on state (ex. if
 300 *                    power-on reset was run). If so, values will only be
 301 *                    written to TP if they differ from power-on default.
 302 */
 303static int trackpoint_sync(struct psmouse *psmouse, bool in_power_on_state)
 304{
 305        struct trackpoint_data *tp = psmouse->private;
 306
 307        if (!in_power_on_state && tp->variant_id == TP_VARIANT_IBM) {
 308                /*
 309                 * Disable features that may make device unusable
 310                 * with this driver.
 311                 */
 312                trackpoint_update_bit(&psmouse->ps2dev, TP_TOGGLE_TWOHAND,
 313                                      TP_MASK_TWOHAND, TP_DEF_TWOHAND);
 314
 315                trackpoint_update_bit(&psmouse->ps2dev, TP_TOGGLE_SOURCE_TAG,
 316                                      TP_MASK_SOURCE_TAG, TP_DEF_SOURCE_TAG);
 317
 318                trackpoint_update_bit(&psmouse->ps2dev, TP_TOGGLE_MB,
 319                                      TP_MASK_MB, TP_DEF_MB);
 320        }
 321
 322        /*
 323         * These properties can be changed in this driver. Only
 324         * configure them if the values are non-default or if the TP is in
 325         * an unknown state.
 326         */
 327        TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, sensitivity);
 328        TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, inertia);
 329        TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, speed);
 330        TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, reach);
 331        TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, draghys);
 332        TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, mindrag);
 333        TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, thresh);
 334        TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, upthresh);
 335        TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, ztime);
 336        TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, jenks);
 337        TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, drift_time);
 338
 339        /* toggles */
 340        TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, press_to_select);
 341        TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, skipback);
 342        TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, ext_dev);
 343
 344        return 0;
 345}
 346
 347static void trackpoint_defaults(struct trackpoint_data *tp)
 348{
 349        TRACKPOINT_SET_POWER_ON_DEFAULT(tp, sensitivity);
 350        TRACKPOINT_SET_POWER_ON_DEFAULT(tp, speed);
 351        TRACKPOINT_SET_POWER_ON_DEFAULT(tp, reach);
 352        TRACKPOINT_SET_POWER_ON_DEFAULT(tp, draghys);
 353        TRACKPOINT_SET_POWER_ON_DEFAULT(tp, mindrag);
 354        TRACKPOINT_SET_POWER_ON_DEFAULT(tp, thresh);
 355        TRACKPOINT_SET_POWER_ON_DEFAULT(tp, upthresh);
 356        TRACKPOINT_SET_POWER_ON_DEFAULT(tp, ztime);
 357        TRACKPOINT_SET_POWER_ON_DEFAULT(tp, jenks);
 358        TRACKPOINT_SET_POWER_ON_DEFAULT(tp, drift_time);
 359        TRACKPOINT_SET_POWER_ON_DEFAULT(tp, inertia);
 360
 361        /* toggles */
 362        TRACKPOINT_SET_POWER_ON_DEFAULT(tp, press_to_select);
 363        TRACKPOINT_SET_POWER_ON_DEFAULT(tp, skipback);
 364        TRACKPOINT_SET_POWER_ON_DEFAULT(tp, ext_dev);
 365}
 366
 367static void trackpoint_disconnect(struct psmouse *psmouse)
 368{
 369        device_remove_group(&psmouse->ps2dev.serio->dev,
 370                            &trackpoint_attr_group);
 371
 372        kfree(psmouse->private);
 373        psmouse->private = NULL;
 374}
 375
 376static int trackpoint_reconnect(struct psmouse *psmouse)
 377{
 378        struct trackpoint_data *tp = psmouse->private;
 379        int error;
 380        bool was_reset;
 381
 382        error = trackpoint_start_protocol(psmouse, NULL, NULL);
 383        if (error)
 384                return error;
 385
 386        was_reset = tp->variant_id == TP_VARIANT_IBM &&
 387                    trackpoint_power_on_reset(&psmouse->ps2dev) == 0;
 388
 389        error = trackpoint_sync(psmouse, was_reset);
 390        if (error)
 391                return error;
 392
 393        return 0;
 394}
 395
 396int trackpoint_detect(struct psmouse *psmouse, bool set_properties)
 397{
 398        struct ps2dev *ps2dev = &psmouse->ps2dev;
 399        struct trackpoint_data *tp;
 400        u8 variant_id;
 401        u8 firmware_id;
 402        u8 button_info;
 403        int error;
 404
 405        error = trackpoint_start_protocol(psmouse, &variant_id, &firmware_id);
 406        if (error)
 407                return error;
 408
 409        if (!set_properties)
 410                return 0;
 411
 412        tp = kzalloc(sizeof(*tp), GFP_KERNEL);
 413        if (!tp)
 414                return -ENOMEM;
 415
 416        trackpoint_defaults(tp);
 417        tp->variant_id = variant_id;
 418        tp->firmware_id = firmware_id;
 419
 420        psmouse->private = tp;
 421
 422        psmouse->vendor = trackpoint_variants[variant_id];
 423        psmouse->name = "TrackPoint";
 424
 425        psmouse->reconnect = trackpoint_reconnect;
 426        psmouse->disconnect = trackpoint_disconnect;
 427
 428        if (variant_id != TP_VARIANT_IBM) {
 429                /* Newer variants do not support extended button query. */
 430                button_info = 0x33;
 431        } else {
 432                error = trackpoint_read(ps2dev, TP_EXT_BTN, &button_info);
 433                if (error) {
 434                        psmouse_warn(psmouse,
 435                                     "failed to get extended button data, assuming 3 buttons\n");
 436                        button_info = 0x33;
 437                } else if (!button_info) {
 438                        psmouse_warn(psmouse,
 439                                     "got 0 in extended button data, assuming 3 buttons\n");
 440                        button_info = 0x33;
 441                }
 442        }
 443
 444        if ((button_info & 0x0f) >= 3)
 445                input_set_capability(psmouse->dev, EV_KEY, BTN_MIDDLE);
 446
 447        __set_bit(INPUT_PROP_POINTER, psmouse->dev->propbit);
 448        __set_bit(INPUT_PROP_POINTING_STICK, psmouse->dev->propbit);
 449
 450        if (variant_id != TP_VARIANT_IBM ||
 451            trackpoint_power_on_reset(ps2dev) != 0) {
 452                /*
 453                 * Write defaults to TP if we did not reset the trackpoint.
 454                 */
 455                trackpoint_sync(psmouse, false);
 456        }
 457
 458        error = device_add_group(&ps2dev->serio->dev, &trackpoint_attr_group);
 459        if (error) {
 460                psmouse_err(psmouse,
 461                            "failed to create sysfs attributes, error: %d\n",
 462                            error);
 463                kfree(psmouse->private);
 464                psmouse->private = NULL;
 465                return -1;
 466        }
 467
 468        psmouse_info(psmouse,
 469                     "%s TrackPoint firmware: 0x%02x, buttons: %d/%d\n",
 470                     psmouse->vendor, firmware_id,
 471                     (button_info & 0xf0) >> 4, button_info & 0x0f);
 472
 473        return 0;
 474}
 475
 476