2 * OLPC HGPK (XO-1) touchpad PS/2 mouse driver
4 * Copyright (c) 2006-2008 One Laptop Per Child
7 * Andres Salomon <dilinger@debian.org>
9 * This driver is partly based on the ALPS driver, which is:
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>
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.
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).
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).
33 #include <linux/input.h>
34 #include <linux/serio.h>
35 #include <linux/libps2.h>
36 #include <linux/delay.h>
43 module_param(tpdebug
, int, 0644);
44 MODULE_PARM_DESC(tpdebug
, "enable debugging, dumping packets to KERN_DEBUG.");
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.");
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");
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");
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");
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");
71 static int autorecal
= 1;
72 module_param(autorecal
, int, 0644);
73 MODULE_PARM_DESC(autorecal
, "enable recalibration in the driver");
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.
83 static void hgpk_jumpy_hack(struct psmouse
*psmouse
, int x
, int y
)
85 struct hgpk_data
*priv
= psmouse
->private;
87 if (abs(x
) > recalib_delta
|| abs(y
) > recalib_delta
) {
88 hgpk_err(psmouse
, ">%dpx jump detected (%d,%d)\n",
90 /* My car gets forty rods to the hogshead and that's the
92 psmouse_queue_work(psmouse
, &priv
->recalib_wq
,
93 msecs_to_jiffies(jumpy_delay
));
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".
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.
112 static void hgpk_spewing_hack(struct psmouse
*psmouse
,
113 int l
, int r
, int x
, int y
)
115 struct hgpk_data
*priv
= psmouse
->private;
117 /* ignore button press packets; many in a row could trigger
118 * a false-positive! */
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
));
132 /* reset every 100 packets */
140 * HGPK Mouse Mode format (standard mouse format, sans middle button)
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
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
150 static int hgpk_validate_byte(unsigned char *packet
)
152 return (packet
[0] & 0x0C) != 0x08;
155 static void hgpk_process_packet(struct psmouse
*psmouse
)
157 struct input_dev
*dev
= psmouse
->dev
;
158 unsigned char *packet
= psmouse
->packet
;
159 int x
, y
, left
, right
;
161 left
= packet
[0] & 1;
162 right
= (packet
[0] >> 1) & 1;
164 x
= packet
[1] - ((packet
[0] << 4) & 0x100);
165 y
= ((packet
[0] << 3) & 0x100) - packet
[2];
167 hgpk_jumpy_hack(psmouse
, x
, y
);
168 hgpk_spewing_hack(psmouse
, left
, right
, x
, y
);
171 hgpk_dbg(psmouse
, "l=%d r=%d x=%d y=%d\n", left
, right
, x
, y
);
173 input_report_key(dev
, BTN_LEFT
, left
);
174 input_report_key(dev
, BTN_RIGHT
, right
);
176 input_report_rel(dev
, REL_X
, x
);
177 input_report_rel(dev
, REL_Y
, y
);
182 static psmouse_ret_t
hgpk_process_byte(struct psmouse
*psmouse
)
184 struct hgpk_data
*priv
= psmouse
->private;
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
;
193 if (psmouse
->pktcnt
>= psmouse
->pktsize
) {
194 hgpk_process_packet(psmouse
);
195 return PSMOUSE_FULL_PACKET
;
198 if (priv
->recalib_window
) {
199 if (time_before(jiffies
, priv
->recalib_window
)) {
201 * ugh, got a packet inside our recalibration
202 * window, schedule another recalibration.
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
));
210 priv
->recalib_window
= 0;
213 return PSMOUSE_GOOD_DATA
;
216 static int hgpk_force_recalibrate(struct psmouse
*psmouse
)
218 struct ps2dev
*ps2dev
= &psmouse
->ps2dev
;
219 struct hgpk_data
*priv
= psmouse
->private;
221 /* C-series touchpads added the recalibrate command */
222 if (psmouse
->model
< HGPK_MODEL_C
)
225 /* we don't want to race with the irq handler, nor with resyncs */
226 psmouse_set_state(psmouse
, PSMOUSE_INITIALIZING
);
228 /* start by resetting the device */
229 psmouse_reset(psmouse
);
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)) {
239 /* according to ALPS, 150mS is required for recalibration */
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.
248 if (ps2_command(ps2dev
, NULL
, PSMOUSE_CMD_ENABLE
))
251 psmouse_set_state(psmouse
, PSMOUSE_ACTIVATED
);
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
258 priv
->recalib_window
= jiffies
+ msecs_to_jiffies(recal_guard_time
);
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
268 static int hgpk_toggle_power(struct psmouse
*psmouse
, int enable
)
270 struct ps2dev
*ps2dev
= &psmouse
->ps2dev
;
273 /* Added on D-series touchpads */
274 if (psmouse
->model
< HGPK_MODEL_D
)
278 psmouse_set_state(psmouse
, PSMOUSE_INITIALIZING
);
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
287 for (timeo
= 20; timeo
> 0; timeo
--) {
288 if (!ps2_sendbyte(&psmouse
->ps2dev
,
289 PSMOUSE_CMD_DISABLE
, 20))
294 psmouse_reset(psmouse
);
296 /* should be all set, enable the touchpad */
297 ps2_command(&psmouse
->ps2dev
, NULL
, PSMOUSE_CMD_ENABLE
);
298 psmouse_set_state(psmouse
, PSMOUSE_ACTIVATED
);
301 hgpk_dbg(psmouse
, "Powering off touchpad.\n");
302 psmouse_set_state(psmouse
, PSMOUSE_IGNORE
);
304 if (ps2_command(ps2dev
, NULL
, 0xec) ||
305 ps2_command(ps2dev
, NULL
, 0xec) ||
306 ps2_command(ps2dev
, NULL
, 0xea)) {
310 /* probably won't see an ACK, the touchpad will be off */
311 ps2_sendbyte(&psmouse
->ps2dev
, 0xec, 20);
317 static int hgpk_poll(struct psmouse
*psmouse
)
319 /* We can't poll, so always return failure. */
323 static int hgpk_reconnect(struct psmouse
*psmouse
)
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
!=
333 psmouse_reset(psmouse
);
338 static ssize_t
hgpk_show_powered(struct psmouse
*psmouse
, void *data
, char *buf
)
340 struct hgpk_data
*priv
= psmouse
->private;
342 return sprintf(buf
, "%d\n", priv
->powered
);
345 static ssize_t
hgpk_set_powered(struct psmouse
*psmouse
, void *data
,
346 const char *buf
, size_t count
)
348 struct hgpk_data
*priv
= psmouse
->private;
352 err
= strict_strtoul(buf
, 10, &value
);
353 if (err
|| value
> 1)
356 if (value
!= priv
->powered
) {
358 * hgpk_toggle_power will deal w/ state so
359 * we're not racing w/ irq
361 err
= hgpk_toggle_power(psmouse
, value
);
363 priv
->powered
= value
;
366 return err
? err
: count
;
369 __PSMOUSE_DEFINE_ATTR(powered
, S_IWUSR
| S_IRUGO
, NULL
,
370 hgpk_show_powered
, hgpk_set_powered
, 0);
372 static void hgpk_disconnect(struct psmouse
*psmouse
)
374 struct hgpk_data
*priv
= psmouse
->private;
376 device_remove_file(&psmouse
->ps2dev
.serio
->dev
,
377 &psmouse_attr_powered
.dattr
);
378 psmouse_reset(psmouse
);
382 static void hgpk_recalib_work(struct work_struct
*work
)
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
;
388 hgpk_dbg(psmouse
, "recalibrating touchpad..\n");
390 if (hgpk_force_recalibrate(psmouse
))
391 hgpk_err(psmouse
, "recalibration failed!\n");
394 static int hgpk_register(struct psmouse
*psmouse
)
396 struct input_dev
*dev
= psmouse
->dev
;
399 /* unset the things that psmouse-base sets which we don't have */
400 __clear_bit(BTN_MIDDLE
, dev
->keybit
);
402 /* set the things we do have */
403 __set_bit(EV_KEY
, dev
->evbit
);
404 __set_bit(EV_REL
, dev
->evbit
);
406 __set_bit(REL_X
, dev
->relbit
);
407 __set_bit(REL_Y
, dev
->relbit
);
409 __set_bit(BTN_LEFT
, dev
->keybit
);
410 __set_bit(BTN_RIGHT
, dev
->keybit
);
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;
419 /* Disable the idle resync. */
420 psmouse
->resync_time
= 0;
421 /* Reset after a lot of bad bytes. */
422 psmouse
->resetafter
= 1024;
424 err
= device_create_file(&psmouse
->ps2dev
.serio
->dev
,
425 &psmouse_attr_powered
.dattr
);
427 hgpk_err(psmouse
, "Failed to create sysfs attribute\n");
432 int hgpk_init(struct psmouse
*psmouse
)
434 struct hgpk_data
*priv
;
437 priv
= kzalloc(sizeof(struct hgpk_data
), GFP_KERNEL
);
441 psmouse
->private = priv
;
442 priv
->psmouse
= psmouse
;
444 INIT_DELAYED_WORK(&priv
->recalib_wq
, hgpk_recalib_work
);
446 err
= psmouse_reset(psmouse
);
450 err
= hgpk_register(psmouse
);
462 static enum hgpk_model_t
hgpk_get_model(struct psmouse
*psmouse
)
464 struct ps2dev
*ps2dev
= &psmouse
->ps2dev
;
465 unsigned char param
[3];
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
)) {
475 hgpk_dbg(psmouse
, "ID: %02x %02x %02x\n", param
[0], param
[1], param
[2]);
477 /* HGPK signature: 0x67, 0x00, 0x<model> */
478 if (param
[0] != 0x67 || param
[1] != 0x00)
481 hgpk_info(psmouse
, "OLPC touchpad revision 0x%x\n", param
[2]);
486 int hgpk_detect(struct psmouse
*psmouse
, int set_properties
)
490 version
= hgpk_get_model(psmouse
);
494 if (set_properties
) {
495 psmouse
->vendor
= "ALPS";
496 psmouse
->name
= "HGPK";
497 psmouse
->model
= version
;