/*
* OLPC HGPK (XO-1) touchpad PS/2 mouse driver
*
* Copyright (c) 2006-2008 One Laptop Per Child
* Authors:
* Zephaniah E. Hull
* Andres Salomon <dilinger@debian.org>
*
* This driver is partly based on the ALPS driver, which is:
*
* Copyright (c) 2003 Neil Brown <neilb@cse.unsw.edu.au>
* Copyright (c) 2003-2005 Peter Osterlund <petero2@telia.com>
* Copyright (c) 2004 Dmitry Torokhov <dtor@mail.ru>
* Copyright (c) 2005 Vojtech Pavlik <vojtech@suse.cz>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
/*
* The spec from ALPS is available from
* <http://wiki.laptop.org/go/Touch_Pad/Tablet>. It refers to this
* device as HGPK (Hybrid GS, PT, and Keymatrix).
*
* The earliest versions of the device had simultaneous reporting; that
* was removed. After that, the device used the Advanced Mode GS/PT streaming
* stuff. That turned out to be too buggy to support, so we've finally
* switched to Mouse Mode (which utilizes only the center 1/3 of the touchpad).
*/
#define DEBUG
#include <linux/input.h>
#include <linux/serio.h>
#include <linux/libps2.h>
#include <linux/delay.h>
#include <asm/olpc.h>
#include "psmouse.h"
#include "hgpk.h"
static int tpdebug;
module_param(tpdebug, int, 0644);
MODULE_PARM_DESC(tpdebug, "enable debugging, dumping packets to KERN_DEBUG.");
static int recalib_delta = 100;
module_param(recalib_delta, int, 0644);
MODULE_PARM_DESC(recalib_delta,
"packets containing a delta this large will cause a recalibration.");
/*
* When the touchpad gets ultra-sensitive, one can keep their finger 1/2"
* above the pad and still have it send packets. This causes a jump cursor
* when one places their finger on the pad. We can probably detect the
* jump as we see a large deltas (>= 100px). In mouse mode, I've been
* unable to even come close to 100px deltas during normal usage, so I think
* this threshold is safe. If a large delta occurs, trigger a recalibration.
*/
static void hgpk_jumpy_hack(struct psmouse *psmouse, int x, int y)
{
struct hgpk_data *priv = psmouse->private;
if (abs(x) > recalib_delta || abs(y) > recalib_delta) {
hgpk_err(psmouse, ">%dpx jump detected (%d,%d)\n",
recalib_delta, x, y);
/* My car gets forty rods to the hogshead and that's the
* way I likes it! */
psmouse_queue_work(psmouse, &priv->recalib_wq,
msecs_to_jiffies(1000));
}
}
/*
* We have no idea why this particular hardware bug occurs. The touchpad
* will randomly start spewing packets without anything touching the
* pad. This wouldn't necessarily be bad, but it's indicative of a
* severely miscalibrated pad; attempting to use the touchpad while it's
* spewing means the cursor will jump all over the place, and act "drunk".
*
* The packets that are spewed tend to all have deltas between -2 and 2, and
* the cursor will move around without really going very far. It will
* tend to end up in the same location; if we tally up the changes over
* 100 packets, we end up w/ a final delta of close to 0. This happens
* pretty regularly when the touchpad is spewing, and is pretty hard to
* manually trigger (at least for *my* fingers). So, it makes a perfect
* scheme for detecting spews.
*/
static void hgpk_spewing_hack(struct psmouse *psmouse,
int l, int r, int x, int y)
{
struct hgpk_data *priv = psmouse->private;
/* ignore button press packets; many in a row could trigger
* a false-positive! */
if (l || r)
return;
priv->x_tally += x;
priv->y_tally += y;
if (++priv->count > 100) {
if (abs(priv->x_tally) < 3 && abs(priv->y_tally) < 3) {
hgpk_dbg(psmouse, "packet spew detected (%d,%d)\n",
priv->x_tally, priv->y_tally);
psmouse_queue_work(psmouse, &priv->recalib_wq,
msecs_to_jiffies(1000));
}
/* reset every 100 packets */
priv->count = 0;
priv->x_tally = 0;
priv->y_tally = 0;
}
}
/*
* HGPK Mouse Mode format (standard mouse format, sans middle button)
*
* byte 0: y-over x-over y-neg x-neg 1 0 swr swl
* byte 1: x7 x6 x5 x4 x3 x2 x1 x0
* byte 2: y7 y6 y5 y4 y3 y2 y1 y0
*
* swr/swl are the left/right buttons.
* x-neg/y-neg are the x and y delta negative bits
* x-over/y-over are the x and y overflow bits
*/
static int hgpk_validate_byte(unsigned char *packet)
{
return (packet[0] & 0x0C) != 0x08;
}
static void hgpk_process_packet(struct psmouse *psmouse)
{
struct input_dev *dev = psmouse->dev;
unsigned char *packet = psmouse->packet;
int x, y, left, right;
left = packet[0] & 1;
right = (packet[0] >> 1) & 1;
x = packet[1] - ((packet[0] << 4) & 0x100);
y = ((packet[0] << 3) & 0x100) - packet[2];
hgpk_jumpy_hack(psmouse, x, y);
hgpk_spewing_hack(psmouse, left, right, x, y);
if (tpdebug)
hgpk_dbg(psmouse, "l=%d r=%d x=%d y=%d\n", left, right, x, y);
input_report_key(dev, BTN_LEFT, left);
input_report_key(dev, BTN_RIGHT, right);
input_report_rel(dev, REL_X, x);
input_report_rel(dev, REL_Y, y);
input_sync(dev);
}
static psmouse_ret_t hgpk_process_byte(struct psmouse *psmouse)
{
struct hgpk_data *priv = psmouse->private;
if (hgpk_validate_byte(psmouse->packet)) {
hgpk_dbg(psmouse, "%s: (%d) %02x %02x %02x\n",
__func__, psmouse->pktcnt, psmouse->packet[0],
psmouse->packet[1], psmouse->packet[2]);
return PSMOUSE_BAD_DATA;
}
if (psmouse->pktcnt >= psmouse->pktsize) {
hgpk_process_packet(psmouse);
return PSMOUSE_FULL_PACKET;
}
if (priv->recalib_window) {
if (time_before(jiffies, priv->recalib_window)) {
/*
* ugh, got a packet inside our recalibration
* window, schedule another recalibration.
*/
hgpk_dbg(psmouse,
"packet inside calibration window, "
"queueing another recalibration\n");
psmouse_queue_work(psmouse, &priv->recalib_wq,
msecs_to_jiffies(1000));
}
priv->recalib_window = 0;
}
return PSMOUSE_GOOD_DATA;
}
static int hgpk_force_recalibrate(struct psmouse *psmouse)
{
struct ps2dev *ps2dev = &psmouse->ps2dev;
struct hgpk_data *priv = psmouse->private;
/* C-series touchpads added the recalibrate command */
if (psmouse->model < HGPK_MODEL_C)
return 0;
/* we don't want to race with the irq handler, nor with resyncs */
psmouse_set_state(psmouse, PSMOUSE_INITIALIZING);
/* start by resetting the device */
psmouse_reset(psmouse);
/* send the recalibrate request */
if (ps2_command(ps2dev, NULL, 0xf5) ||
ps2_command(ps2dev, NULL, 0xf5) ||
ps2_command(ps2dev, NULL, 0xe6) ||
ps2_command(ps2dev, NULL, 0xf5)) {
return -1;
}
/* according to ALPS, 150mS is required for recalibration */
msleep(150);
/* XXX: If a finger is down during this delay, recalibration will
* detect capacitance incorrectly. This is a hardware bug, and
* we don't have a good way to deal with it. The 2s window stuff
* (below) is our best option for now.
*/
if (ps2_command(ps2dev, NULL, PSMOUSE_CMD_ENABLE))
return -1;
psmouse_set_state(psmouse, PSMOUSE_ACTIVATED);
/* After we recalibrate, we shouldn't get any packets for 2s. If
* we do, it's likely that someone's finger was on the touchpad.
* If someone's finger *was* on the touchpad, it's probably
* miscalibrated. So, we should schedule another recalibration
*/
priv->recalib_window = jiffies + msecs_to_jiffies(2000);
return 0;
}
/*
* This kills power to the touchpad; according to ALPS, current consumption
* goes down to 50uA after running this. To turn power back on, we drive
* MS-DAT low.
*/
static int hgpk_toggle_power(struct psmouse *psmouse, int enable)
{
struct ps2dev *ps2dev = &psmouse->ps2dev;
int timeo;
/* Added on D-series touchpads */
if (psmouse->model < HGPK_MODEL_D)
return 0;
if (enable) {
psmouse_set_state(psmouse, PSMOUSE_INITIALIZING);
/*
* Sending a byte will drive MS-DAT low; this will wake up
* the controller. Once we get an ACK back from it, it
* means we can continue with the touchpad re-init. ALPS
* tells us that 1s should be long enough, so set that as
* the upper bound.
*/
for (timeo = 20; timeo > 0; timeo--) {
if (!ps2_sendbyte(&psmouse->ps2dev,
PSMOUSE_CMD_DISABLE, 20))
break;
msleep(50);
}
psmouse_reset(psmouse);
/* should be all set, enable the touchpad */
ps2_command(&psmouse->ps2dev, NULL, PSMOUSE_CMD_ENABLE);
psmouse_set_state(psmouse, PSMOUSE_ACTIVATED);
} else {
hgpk_dbg(psmouse, "Powering off touchpad.\n");
psmouse_set_state(psmouse, PSMOUSE_IGNORE);
if (ps2_command(ps2dev, NULL, 0xec) ||
ps2_command(ps2dev, NULL, 0xec) ||
ps2_command(ps2dev, NULL, 0xea)) {
return -1;
}
/* probably won't see an ACK, the touchpad will be off */
ps2_sendbyte(&psmouse->ps2dev, 0xec, 20);
}
return 0;
}
static int hgpk_poll(struct psmouse *psmouse)
{
/* We can't poll, so always return failure. */
return -1;
}
static int hgpk_reconnect(struct psmouse *psmouse)
{
/* During suspend/resume the ps2 rails remain powered. We don't want
* to do a reset because it's flush data out of buffers; however,
* earlier prototypes (B1) had some brokenness that required a reset. */
if (olpc_board_at_least(olpc_board(0xb2)))
if (psmouse->ps2dev.serio->dev.power.power_state.event !=
PM_EVENT_ON)
return 0;
psmouse_reset(psmouse);
return 0;
}
static ssize_t hgpk_show_powered(struct psmouse *psmouse, void *data, char *buf)
{
struct hgpk_data *priv = psmouse->private;
return sprintf(buf, "%d\n", priv->powered);
}
static ssize_t hgpk_set_powered(struct psmouse *psmouse, void *data,
const char *buf, size_t count)
{
struct hgpk_data *priv = psmouse->private;
unsigned long value;
int err;
err = strict_strtoul(buf, 10, &value);
if (err || value > 1)
return -EINVAL;
if (value != priv->powered) {
/*
* hgpk_toggle_power will deal w/ state so
* we're not racing w/ irq
*/
err = hgpk_toggle_power(psmouse, value);
if (!err)
priv->powered = value;
}
return err ? err : count;
}
__PSMOUSE_DEFINE_ATTR(powered, S_IWUSR | S_IRUGO, NULL,
hgpk_show_powered, hgpk_set_powered, 0);
static void hgpk_disconnect(struct psmouse *psmouse)
{
struct hgpk_data *priv = psmouse->private;
device_remove_file(&psmouse->ps2dev.serio->dev,
&psmouse_attr_powered.dattr);
psmouse_reset(psmouse);
kfree(priv);
}
static void hgpk_recalib_work(struct work_struct *work)
{
struct delayed_work *w = container_of(work, struct delayed_work, work);
struct hgpk_data *priv = container_of(w, struct hgpk_data, recalib_wq);
struct psmouse *psmouse = priv->psmouse;
hgpk_dbg(psmouse, "recalibrating touchpad..\n");
if (hgpk_force_recalibrate(psmouse))
hgpk_err(psmouse, "recalibration failed!\n");
}
static int hgpk_register(struct psmouse *psmouse)
{
struct input_dev *dev = psmouse->dev;
int err;
/* unset the things that psmouse-base sets which we don't have */
__clear_bit(BTN_MIDDLE, dev->keybit);
/* set the things we do have */
__set_bit(EV_KEY, dev->evbit);
__set_bit(EV_REL, dev->evbit);
__set_bit(REL_X, dev->relbit);
__set_bit(REL_Y, dev->relbit);
__set_bit(BTN_LEFT, dev->keybit);
__set_bit(BTN_RIGHT, dev->keybit);
/* register handlers */
psmouse->protocol_handler = hgpk_process_byte;
psmouse->poll = hgpk_poll;
psmouse->disconnect = hgpk_disconnect;
psmouse->reconnect = hgpk_reconnect;
psmouse->pktsize = 3;
/* Disable the idle resync. */
psmouse->resync_time = 0;
/* Reset after a lot of bad bytes. */
psmouse->resetafter = 1024;
err = device_create_file(&psmouse->ps2dev.serio->dev,
&psmouse_attr_powered.dattr);
if (err)
hgpk_err(psmouse, "Failed to create sysfs attribute\n");
return err;
}
int hgpk_init(struct psmouse *psmouse)
{
struct hgpk_data *priv;
int err = -ENOMEM;
priv = kzalloc(sizeof(struct hgpk_data), GFP_KERNEL);
if (!priv)
goto alloc_fail;
psmouse->private = priv;
priv->psmouse = psmouse;
priv->powered = 1;
INIT_DELAYED_WORK(&priv->recalib_wq, hgpk_recalib_work);
err = psmouse_reset(psmouse);
if (err)
goto init_fail;
err = hgpk_register(psmouse);
if (err)
goto init_fail;
return 0;
init_fail:
kfree(priv);
alloc_fail:
return err;
}
static enum hgpk_model_t hgpk_get_model(struct psmouse *psmouse)
{
struct ps2dev *ps2dev = &psmouse->ps2dev;
unsigned char param[3];
/* E7, E7, E7, E9 gets us a 3 byte identifier */
if (ps2_command(ps2dev, NULL, PSMOUSE_CMD_SETSCALE21) ||
ps2_command(ps2dev, NULL, PSMOUSE_CMD_SETSCALE21) ||
ps2_command(ps2dev, NULL, PSMOUSE_CMD_SETSCALE21) ||
ps2_command(ps2dev, param, PSMOUSE_CMD_GETINFO)) {
return -EIO;
}
hgpk_dbg(psmouse, "ID: %02x %02x %02x", param[0], param[1], param[2]);
/* HGPK signature: 0x67, 0x00, 0x<model> */
if (param[0] != 0x67 || param[1] != 0x00)
return -ENODEV;
hgpk_info(psmouse, "OLPC touchpad revision 0x%x\n", param[2]);
return param[2];
}
int hgpk_detect(struct psmouse *psmouse, int set_properties)
{
int version;
version = hgpk_get_model(psmouse);
if (version < 0)
return version;
if (set_properties) {
psmouse->vendor = "ALPS";
psmouse->name = "HGPK";
psmouse->model = version;
}
return 0;
}
