1 /* 2 * OLPC HGPK (XO-1) touchpad PS/2 mouse driver 3 * 4 * Copyright (c) 2006-2008 One Laptop Per Child 5 * Authors: 6 * Zephaniah E. Hull 7 * Andres Salomon <dilinger@debian.org> 8 * 9 * This driver is partly based on the ALPS driver, which is: 10 * 11 * Copyright (c) 2003 Neil Brown <neilb@cse.unsw.edu.au> 12 * Copyright (c) 2003-2005 Peter Osterlund <petero2@telia.com> 13 * Copyright (c) 2004 Dmitry Torokhov <dtor@mail.ru> 14 * Copyright (c) 2005 Vojtech Pavlik <vojtech@suse.cz> 15 * 16 * This program is free software; you can redistribute it and/or modify 17 * it under the terms of the GNU General Public License version 2 as 18 * published by the Free Software Foundation. 19 */ 20 21 /* 22 * The spec from ALPS is available from 23 * <http://wiki.laptop.org/go/Touch_Pad/Tablet>. It refers to this 24 * device as HGPK (Hybrid GS, PT, and Keymatrix). 25 * 26 * The earliest versions of the device had simultaneous reporting; that 27 * was removed. After that, the device used the Advanced Mode GS/PT streaming 28 * stuff. That turned out to be too buggy to support, so we've finally 29 * switched to Mouse Mode (which utilizes only the center 1/3 of the touchpad). 30 */ 31 32 #define DEBUG 33 #include <linux/slab.h> 34 #include <linux/input.h> 35 #include <linux/serio.h> 36 #include <linux/libps2.h> 37 #include <linux/delay.h> 38 #include <asm/olpc.h> 39 40 #include "psmouse.h" 41 #include "hgpk.h" 42 43 static bool tpdebug; 44 module_param(tpdebug, bool, 0644); 45 MODULE_PARM_DESC(tpdebug, "enable debugging, dumping packets to KERN_DEBUG."); 46 47 static int recalib_delta = 100; 48 module_param(recalib_delta, int, 0644); 49 MODULE_PARM_DESC(recalib_delta, 50 "packets containing a delta this large will cause a recalibration."); 51 52 static int jumpy_delay = 1000; 53 module_param(jumpy_delay, int, 0644); 54 MODULE_PARM_DESC(jumpy_delay, 55 "delay (ms) before recal after jumpiness detected"); 56 57 static int spew_delay = 1000; 58 module_param(spew_delay, int, 0644); 59 MODULE_PARM_DESC(spew_delay, 60 "delay (ms) before recal after packet spew detected"); 61 62 static int recal_guard_time = 2000; 63 module_param(recal_guard_time, int, 0644); 64 MODULE_PARM_DESC(recal_guard_time, 65 "interval (ms) during which recal will be restarted if packet received"); 66 67 static int post_interrupt_delay = 1000; 68 module_param(post_interrupt_delay, int, 0644); 69 MODULE_PARM_DESC(post_interrupt_delay, 70 "delay (ms) before recal after recal interrupt detected"); 71 72 /* 73 * When the touchpad gets ultra-sensitive, one can keep their finger 1/2" 74 * above the pad and still have it send packets. This causes a jump cursor 75 * when one places their finger on the pad. We can probably detect the 76 * jump as we see a large deltas (>= 100px). In mouse mode, I've been 77 * unable to even come close to 100px deltas during normal usage, so I think 78 * this threshold is safe. If a large delta occurs, trigger a recalibration. 79 */ 80 static void hgpk_jumpy_hack(struct psmouse *psmouse, int x, int y) 81 { 82 struct hgpk_data *priv = psmouse->private; 83 84 if (abs(x) > recalib_delta || abs(y) > recalib_delta) { 85 hgpk_err(psmouse, ">%dpx jump detected (%d,%d)\n", 86 recalib_delta, x, y); 87 /* My car gets forty rods to the hogshead and that's the 88 * way I likes it! */ 89 psmouse_queue_work(psmouse, &priv->recalib_wq, 90 msecs_to_jiffies(jumpy_delay)); 91 } 92 } 93 94 /* 95 * We have no idea why this particular hardware bug occurs. The touchpad 96 * will randomly start spewing packets without anything touching the 97 * pad. This wouldn't necessarily be bad, but it's indicative of a 98 * severely miscalibrated pad; attempting to use the touchpad while it's 99 * spewing means the cursor will jump all over the place, and act "drunk". 100 * 101 * The packets that are spewed tend to all have deltas between -2 and 2, and 102 * the cursor will move around without really going very far. It will 103 * tend to end up in the same location; if we tally up the changes over 104 * 100 packets, we end up w/ a final delta of close to 0. This happens 105 * pretty regularly when the touchpad is spewing, and is pretty hard to 106 * manually trigger (at least for *my* fingers). So, it makes a perfect 107 * scheme for detecting spews. 108 */ 109 static void hgpk_spewing_hack(struct psmouse *psmouse, 110 int l, int r, int x, int y) 111 { 112 struct hgpk_data *priv = psmouse->private; 113 114 /* ignore button press packets; many in a row could trigger 115 * a false-positive! */ 116 if (l || r) 117 return; 118 119 priv->x_tally += x; 120 priv->y_tally += y; 121 122 if (++priv->count > 100) { 123 if (abs(priv->x_tally) < 3 && abs(priv->y_tally) < 3) { 124 hgpk_dbg(psmouse, "packet spew detected (%d,%d)\n", 125 priv->x_tally, priv->y_tally); 126 psmouse_queue_work(psmouse, &priv->recalib_wq, 127 msecs_to_jiffies(spew_delay)); 128 } 129 /* reset every 100 packets */ 130 priv->count = 0; 131 priv->x_tally = 0; 132 priv->y_tally = 0; 133 } 134 } 135 136 /* 137 * HGPK Mouse Mode format (standard mouse format, sans middle button) 138 * 139 * byte 0: y-over x-over y-neg x-neg 1 0 swr swl 140 * byte 1: x7 x6 x5 x4 x3 x2 x1 x0 141 * byte 2: y7 y6 y5 y4 y3 y2 y1 y0 142 * 143 * swr/swl are the left/right buttons. 144 * x-neg/y-neg are the x and y delta negative bits 145 * x-over/y-over are the x and y overflow bits 146 */ 147 static int hgpk_validate_byte(unsigned char *packet) 148 { 149 return (packet[0] & 0x0C) != 0x08; 150 } 151 152 static void hgpk_process_packet(struct psmouse *psmouse) 153 { 154 struct input_dev *dev = psmouse->dev; 155 unsigned char *packet = psmouse->packet; 156 int x, y, left, right; 157 158 left = packet[0] & 1; 159 right = (packet[0] >> 1) & 1; 160 161 x = packet[1] - ((packet[0] << 4) & 0x100); 162 y = ((packet[0] << 3) & 0x100) - packet[2]; 163 164 hgpk_jumpy_hack(psmouse, x, y); 165 hgpk_spewing_hack(psmouse, left, right, x, y); 166 167 if (tpdebug) 168 hgpk_dbg(psmouse, "l=%d r=%d x=%d y=%d\n", left, right, x, y); 169 170 input_report_key(dev, BTN_LEFT, left); 171 input_report_key(dev, BTN_RIGHT, right); 172 173 input_report_rel(dev, REL_X, x); 174 input_report_rel(dev, REL_Y, y); 175 176 input_sync(dev); 177 } 178 179 static psmouse_ret_t hgpk_process_byte(struct psmouse *psmouse) 180 { 181 struct hgpk_data *priv = psmouse->private; 182 183 if (hgpk_validate_byte(psmouse->packet)) { 184 hgpk_dbg(psmouse, "%s: (%d) %02x %02x %02x\n", 185 __func__, psmouse->pktcnt, psmouse->packet[0], 186 psmouse->packet[1], psmouse->packet[2]); 187 return PSMOUSE_BAD_DATA; 188 } 189 190 if (psmouse->pktcnt >= psmouse->pktsize) { 191 hgpk_process_packet(psmouse); 192 return PSMOUSE_FULL_PACKET; 193 } 194 195 if (priv->recalib_window) { 196 if (time_before(jiffies, priv->recalib_window)) { 197 /* 198 * ugh, got a packet inside our recalibration 199 * window, schedule another recalibration. 200 */ 201 hgpk_dbg(psmouse, 202 "packet inside calibration window, " 203 "queueing another recalibration\n"); 204 psmouse_queue_work(psmouse, &priv->recalib_wq, 205 msecs_to_jiffies(post_interrupt_delay)); 206 } 207 priv->recalib_window = 0; 208 } 209 210 return PSMOUSE_GOOD_DATA; 211 } 212 213 static int hgpk_force_recalibrate(struct psmouse *psmouse) 214 { 215 struct ps2dev *ps2dev = &psmouse->ps2dev; 216 struct hgpk_data *priv = psmouse->private; 217 218 /* C-series touchpads added the recalibrate command */ 219 if (psmouse->model < HGPK_MODEL_C) 220 return 0; 221 222 /* we don't want to race with the irq handler, nor with resyncs */ 223 psmouse_set_state(psmouse, PSMOUSE_INITIALIZING); 224 225 /* start by resetting the device */ 226 psmouse_reset(psmouse); 227 228 /* send the recalibrate request */ 229 if (ps2_command(ps2dev, NULL, 0xf5) || 230 ps2_command(ps2dev, NULL, 0xf5) || 231 ps2_command(ps2dev, NULL, 0xe6) || 232 ps2_command(ps2dev, NULL, 0xf5)) { 233 return -1; 234 } 235 236 /* according to ALPS, 150mS is required for recalibration */ 237 msleep(150); 238 239 /* XXX: If a finger is down during this delay, recalibration will 240 * detect capacitance incorrectly. This is a hardware bug, and 241 * we don't have a good way to deal with it. The 2s window stuff 242 * (below) is our best option for now. 243 */ 244 245 if (ps2_command(ps2dev, NULL, PSMOUSE_CMD_ENABLE)) 246 return -1; 247 248 psmouse_set_state(psmouse, PSMOUSE_ACTIVATED); 249 250 /* After we recalibrate, we shouldn't get any packets for 2s. If 251 * we do, it's likely that someone's finger was on the touchpad. 252 * If someone's finger *was* on the touchpad, it's probably 253 * miscalibrated. So, we should schedule another recalibration 254 */ 255 priv->recalib_window = jiffies + msecs_to_jiffies(recal_guard_time); 256 257 return 0; 258 } 259 260 /* 261 * This kills power to the touchpad; according to ALPS, current consumption 262 * goes down to 50uA after running this. To turn power back on, we drive 263 * MS-DAT low. 264 */ 265 static int hgpk_toggle_power(struct psmouse *psmouse, int enable) 266 { 267 struct ps2dev *ps2dev = &psmouse->ps2dev; 268 int timeo; 269 270 /* Added on D-series touchpads */ 271 if (psmouse->model < HGPK_MODEL_D) 272 return 0; 273 274 if (enable) { 275 psmouse_set_state(psmouse, PSMOUSE_INITIALIZING); 276 277 /* 278 * Sending a byte will drive MS-DAT low; this will wake up 279 * the controller. Once we get an ACK back from it, it 280 * means we can continue with the touchpad re-init. ALPS 281 * tells us that 1s should be long enough, so set that as 282 * the upper bound. 283 */ 284 for (timeo = 20; timeo > 0; timeo--) { 285 if (!ps2_sendbyte(&psmouse->ps2dev, 286 PSMOUSE_CMD_DISABLE, 20)) 287 break; 288 msleep(50); 289 } 290 291 psmouse_reset(psmouse); 292 293 /* should be all set, enable the touchpad */ 294 ps2_command(&psmouse->ps2dev, NULL, PSMOUSE_CMD_ENABLE); 295 psmouse_set_state(psmouse, PSMOUSE_ACTIVATED); 296 297 } else { 298 hgpk_dbg(psmouse, "Powering off touchpad.\n"); 299 psmouse_set_state(psmouse, PSMOUSE_IGNORE); 300 301 if (ps2_command(ps2dev, NULL, 0xec) || 302 ps2_command(ps2dev, NULL, 0xec) || 303 ps2_command(ps2dev, NULL, 0xea)) { 304 return -1; 305 } 306 307 /* probably won't see an ACK, the touchpad will be off */ 308 ps2_sendbyte(&psmouse->ps2dev, 0xec, 20); 309 } 310 311 return 0; 312 } 313 314 static int hgpk_poll(struct psmouse *psmouse) 315 { 316 /* We can't poll, so always return failure. */ 317 return -1; 318 } 319 320 static int hgpk_reconnect(struct psmouse *psmouse) 321 { 322 /* During suspend/resume the ps2 rails remain powered. We don't want 323 * to do a reset because it's flush data out of buffers; however, 324 * earlier prototypes (B1) had some brokenness that required a reset. */ 325 if (olpc_board_at_least(olpc_board(0xb2))) 326 if (psmouse->ps2dev.serio->dev.power.power_state.event != 327 PM_EVENT_ON) 328 return 0; 329 330 psmouse_reset(psmouse); 331 332 return 0; 333 } 334 335 static ssize_t hgpk_show_powered(struct psmouse *psmouse, void *data, char *buf) 336 { 337 struct hgpk_data *priv = psmouse->private; 338 339 return sprintf(buf, "%d\n", priv->powered); 340 } 341 342 static ssize_t hgpk_set_powered(struct psmouse *psmouse, void *data, 343 const char *buf, size_t count) 344 { 345 struct hgpk_data *priv = psmouse->private; 346 unsigned long value; 347 int err; 348 349 err = strict_strtoul(buf, 10, &value); 350 if (err || value > 1) 351 return -EINVAL; 352 353 if (value != priv->powered) { 354 /* 355 * hgpk_toggle_power will deal w/ state so 356 * we're not racing w/ irq 357 */ 358 err = hgpk_toggle_power(psmouse, value); 359 if (!err) 360 priv->powered = value; 361 } 362 363 return err ? err : count; 364 } 365 366 __PSMOUSE_DEFINE_ATTR(powered, S_IWUSR | S_IRUGO, NULL, 367 hgpk_show_powered, hgpk_set_powered, false); 368 369 static ssize_t hgpk_trigger_recal_show(struct psmouse *psmouse, 370 void *data, char *buf) 371 { 372 return -EINVAL; 373 } 374 375 static ssize_t hgpk_trigger_recal(struct psmouse *psmouse, void *data, 376 const char *buf, size_t count) 377 { 378 struct hgpk_data *priv = psmouse->private; 379 unsigned long value; 380 int err; 381 382 err = strict_strtoul(buf, 10, &value); 383 if (err || value != 1) 384 return -EINVAL; 385 386 /* 387 * We queue work instead of doing recalibration right here 388 * to avoid adding locking to to hgpk_force_recalibrate() 389 * since workqueue provides serialization. 390 */ 391 psmouse_queue_work(psmouse, &priv->recalib_wq, 0); 392 return count; 393 } 394 395 __PSMOUSE_DEFINE_ATTR(recalibrate, S_IWUSR | S_IRUGO, NULL, 396 hgpk_trigger_recal_show, hgpk_trigger_recal, false); 397 398 static void hgpk_disconnect(struct psmouse *psmouse) 399 { 400 struct hgpk_data *priv = psmouse->private; 401 402 device_remove_file(&psmouse->ps2dev.serio->dev, 403 &psmouse_attr_powered.dattr); 404 405 if (psmouse->model >= HGPK_MODEL_C) 406 device_remove_file(&psmouse->ps2dev.serio->dev, 407 &psmouse_attr_recalibrate.dattr); 408 409 psmouse_reset(psmouse); 410 kfree(priv); 411 } 412 413 static void hgpk_recalib_work(struct work_struct *work) 414 { 415 struct delayed_work *w = to_delayed_work(work); 416 struct hgpk_data *priv = container_of(w, struct hgpk_data, recalib_wq); 417 struct psmouse *psmouse = priv->psmouse; 418 419 hgpk_dbg(psmouse, "recalibrating touchpad..\n"); 420 421 if (hgpk_force_recalibrate(psmouse)) 422 hgpk_err(psmouse, "recalibration failed!\n"); 423 } 424 425 static int hgpk_register(struct psmouse *psmouse) 426 { 427 int err; 428 429 /* register handlers */ 430 psmouse->protocol_handler = hgpk_process_byte; 431 psmouse->poll = hgpk_poll; 432 psmouse->disconnect = hgpk_disconnect; 433 psmouse->reconnect = hgpk_reconnect; 434 psmouse->pktsize = 3; 435 436 /* Disable the idle resync. */ 437 psmouse->resync_time = 0; 438 /* Reset after a lot of bad bytes. */ 439 psmouse->resetafter = 1024; 440 441 err = device_create_file(&psmouse->ps2dev.serio->dev, 442 &psmouse_attr_powered.dattr); 443 if (err) { 444 hgpk_err(psmouse, "Failed creating 'powered' sysfs node\n"); 445 return err; 446 } 447 448 /* C-series touchpads added the recalibrate command */ 449 if (psmouse->model >= HGPK_MODEL_C) { 450 err = device_create_file(&psmouse->ps2dev.serio->dev, 451 &psmouse_attr_recalibrate.dattr); 452 if (err) { 453 hgpk_err(psmouse, 454 "Failed creating 'recalibrate' sysfs node\n"); 455 device_remove_file(&psmouse->ps2dev.serio->dev, 456 &psmouse_attr_powered.dattr); 457 return err; 458 } 459 } 460 461 return 0; 462 } 463 464 int hgpk_init(struct psmouse *psmouse) 465 { 466 struct hgpk_data *priv; 467 int err = -ENOMEM; 468 469 priv = kzalloc(sizeof(struct hgpk_data), GFP_KERNEL); 470 if (!priv) 471 goto alloc_fail; 472 473 psmouse->private = priv; 474 priv->psmouse = psmouse; 475 priv->powered = true; 476 INIT_DELAYED_WORK(&priv->recalib_wq, hgpk_recalib_work); 477 478 err = psmouse_reset(psmouse); 479 if (err) 480 goto init_fail; 481 482 err = hgpk_register(psmouse); 483 if (err) 484 goto init_fail; 485 486 return 0; 487 488 init_fail: 489 kfree(priv); 490 alloc_fail: 491 return err; 492 } 493 494 static enum hgpk_model_t hgpk_get_model(struct psmouse *psmouse) 495 { 496 struct ps2dev *ps2dev = &psmouse->ps2dev; 497 unsigned char param[3]; 498 499 /* E7, E7, E7, E9 gets us a 3 byte identifier */ 500 if (ps2_command(ps2dev, NULL, PSMOUSE_CMD_SETSCALE21) || 501 ps2_command(ps2dev, NULL, PSMOUSE_CMD_SETSCALE21) || 502 ps2_command(ps2dev, NULL, PSMOUSE_CMD_SETSCALE21) || 503 ps2_command(ps2dev, param, PSMOUSE_CMD_GETINFO)) { 504 return -EIO; 505 } 506 507 hgpk_dbg(psmouse, "ID: %02x %02x %02x\n", param[0], param[1], param[2]); 508 509 /* HGPK signature: 0x67, 0x00, 0x<model> */ 510 if (param[0] != 0x67 || param[1] != 0x00) 511 return -ENODEV; 512 513 hgpk_info(psmouse, "OLPC touchpad revision 0x%x\n", param[2]); 514 515 return param[2]; 516 } 517 518 int hgpk_detect(struct psmouse *psmouse, bool set_properties) 519 { 520 int version; 521 522 version = hgpk_get_model(psmouse); 523 if (version < 0) 524 return version; 525 526 if (set_properties) { 527 psmouse->vendor = "ALPS"; 528 psmouse->name = "HGPK"; 529 psmouse->model = version; 530 } 531 532 return 0; 533 } 534