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