drivers/input/mouse/trackpoint.c

   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
  19 static 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  */
  33 static 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  */
  52 static 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
  59 static 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
  66 static 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
  77 static 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  */
  96 struct trackpoint_attr_data {
  97         size_t field_offset;
  98         u8 command;
  99         u8 mask;
 100         bool inverted;
 101         u8 power_on_default;
 102 };
 103
 104 static 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
 117 static 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
 146 static 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)     \
 173 static 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         };                                                              \
 181 PSMOUSE_DEFINE_ATTR(_name, S_IWUSR | S_IRUGO,                           \
 182                     &trackpoint_attr_##_name,                           \
 183                     trackpoint_show_int_attr, trackpoint_set_bit_attr)
 184
 185 TRACKPOINT_INT_ATTR(sensitivity, TP_SENS, TP_DEF_SENS);
 186 TRACKPOINT_INT_ATTR(speed, TP_SPEED, TP_DEF_SPEED);
 187 TRACKPOINT_INT_ATTR(inertia, TP_INERTIA, TP_DEF_INERTIA);
 188 TRACKPOINT_INT_ATTR(reach, TP_REACH, TP_DEF_REACH);
 189 TRACKPOINT_INT_ATTR(draghys, TP_DRAGHYS, TP_DEF_DRAGHYS);
 190 TRACKPOINT_INT_ATTR(mindrag, TP_MINDRAG, TP_DEF_MINDRAG);
 191 TRACKPOINT_INT_ATTR(thresh, TP_THRESH, TP_DEF_THRESH);
 192 TRACKPOINT_INT_ATTR(upthresh, TP_UP_THRESH, TP_DEF_UP_THRESH);
 193 TRACKPOINT_INT_ATTR(ztime, TP_Z_TIME, TP_DEF_Z_TIME);
 194 TRACKPOINT_INT_ATTR(jenks, TP_JENKS_CURV, TP_DEF_JENKS_CURV);
 195 TRACKPOINT_INT_ATTR(drift_time, TP_DRIFT_TIME, TP_DEF_DRIFT_TIME);
 196
 197 TRACKPOINT_BIT_ATTR(press_to_select, TP_TOGGLE_PTSON, TP_MASK_PTSON, false,
 198                     TP_DEF_PTSON);
 199 TRACKPOINT_BIT_ATTR(skipback, TP_TOGGLE_SKIPBACK, TP_MASK_SKIPBACK, false,
 200                     TP_DEF_SKIPBACK);
 201 TRACKPOINT_BIT_ATTR(ext_dev, TP_TOGGLE_EXT_DEV, TP_MASK_EXT_DEV, true,
 202                     TP_DEF_EXT_DEV);
 203
 204 static 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
 214 static umode_t trackpoint_is_attr_visible(struct kobject *kobj,
 215                                           struct attribute *attr, int n)
 216 {
 217         struct device *dev = container_of(kobj, struct device, 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
 224 static 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
 242 static 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)              \
 248 do {                                                                    \
 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)                     \
 265 do {                                                                    \
 266         _tp->_name = trackpoint_attr_##_name.power_on_default;          \
 267 } while (0)
 268
 269 static 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  */
 303 static 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
 347 static 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
 367 static 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
 376 static 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
 396 int 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