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