[PATCH 3/3] OLPC: touchpad driver (take 2)

[PATCH 3/3] OLPC: touchpad driver (take 2)

[Andres Salomon]

This adds support for OLPC's touchpad.  It has lots of neat features,
none of which are enabled because the hardware is too buggy.  Instead,
we use it like a normal touchpad, but with a number of workarounds in
place to deal with the frequent hardware spasms.  Humidity changes,
sweat, tinfoil underwear, plugging in AC, drinks, evil felines.. All
tend to cause the touchpad to freak out.

Stuff like this keeps me from getting bored.

We make use of psmouse_set_state and psmouse_queue_work quite a bit.

(also, extension renamed from olpc.c to hgpk.c)

Signed-off-by: Andres Salomon <dilinger@debian.org>
---
 drivers/input/mouse/Kconfig        |   10 +
 drivers/input/mouse/Makefile       |    1 +
 drivers/input/mouse/hgpk.c         |  492 ++++++++++++++++++++++++++++++++++++
 drivers/input/mouse/hgpk.h         |   48 ++++
 drivers/input/mouse/psmouse-base.c |   23 ++-
 drivers/input/mouse/psmouse.h      |    2 +-
 6 files changed, 574 insertions(+), 2 deletions(-)
 create mode 100644 drivers/input/mouse/hgpk.c
 create mode 100644 drivers/input/mouse/hgpk.h

diff --git a/drivers/input/mouse/Kconfig b/drivers/input/mouse/Kconfig
index 7bbea09..fff0253 100644
--- a/drivers/input/mouse/Kconfig
+++ b/drivers/input/mouse/Kconfig
@@ -96,6 +96,16 @@ config MOUSE_PS2_TOUCHKIT
 
 	  If unsure, say N.
 
+config MOUSE_PS2_OLPC
+	bool "OLPC PS/2 mouse protocol extension"
+	depends on MOUSE_PS2 && OLPC
+	help
+	  Say Y here if you have an OLPC XO-1 laptop (with built-in
+	  PS/2 touchpad/tablet device).  The manufacturer calls the
+	  touchpad an HGPK.
+
+	  If unsure, say N.
+
 config MOUSE_SERIAL
 	tristate "Serial mouse"
 	select SERIO
diff --git a/drivers/input/mouse/Makefile b/drivers/input/mouse/Makefile
index 9e6e363..799aa3f 100644
--- a/drivers/input/mouse/Makefile
+++ b/drivers/input/mouse/Makefile
@@ -24,3 +24,4 @@ psmouse-$(CONFIG_MOUSE_PS2_LOGIPS2PP)	+= logips2pp.o
 psmouse-$(CONFIG_MOUSE_PS2_LIFEBOOK)	+= lifebook.o
 psmouse-$(CONFIG_MOUSE_PS2_TRACKPOINT)	+= trackpoint.o
 psmouse-$(CONFIG_MOUSE_PS2_TOUCHKIT)	+= touchkit_ps2.o
+psmouse-$(CONFIG_MOUSE_PS2_OLPC)	+= hgpk.o
diff --git a/drivers/input/mouse/hgpk.c b/drivers/input/mouse/hgpk.c
new file mode 100644
index 0000000..ac7c2a8
--- /dev/null
+++ b/drivers/input/mouse/hgpk.c
@@ -0,0 +1,492 @@
+/*
+ * 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;
+	static int count;
+	static int x_tally;
+	static int y_tally;
+
+	/* ignore button press packets; many in a row could trigger
+	 * a false-positive! */
+	if (l || r)
+		return;
+
+	count++;
+	x_tally += x;
+	y_tally += y;
+	if (count > 100) {
+		if (abs(x_tally) < 3 && abs(y_tally) < 3) {
+			hgpk_dbg(psmouse, "packet spew detected (%d,%d). :(\n",
+					x_tally, y_tally);
+			psmouse_queue_work(psmouse, &priv->recalib_wq,
+					msecs_to_jiffies(1000));
+		}
+		/* reset every 100 packets */
+		count = 0;
+		x_tally = 0;
+		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)
+{
+	if (!(packet[0] & (1<<3)) || (packet[0] & (1<<2)))
+		return -1;
+
+	return 0;
+}
+
+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);
+
+	} 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)
+{
+	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 device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	struct serio *serio = to_serio_port(dev);
+	struct psmouse *psmouse;
+	struct hgpk_data *priv;
+	int retval;
+
+	retval = serio_pin_driver(serio);
+	if (retval)
+		return retval;
+
+	psmouse = serio_get_drvdata(serio);
+	priv = psmouse->private;
+
+	retval = sprintf(buf, "%d\n", priv->powered);
+	serio_unpin_driver(serio);
+	return retval;
+}
+
+static ssize_t hgpk_set_powered(struct device *dev,
+		struct device_attribute *attr, const char *buf, size_t count)
+{
+	struct serio *serio = to_serio_port(dev);
+	struct psmouse *psmouse;
+	struct hgpk_data *priv;
+	unsigned long val;
+	int retval;
+
+	if (*buf == '1')
+		val = 1;
+	else if (*buf == '0')
+		val = 0;
+	else
+		return -EINVAL;
+
+	retval = serio_pin_driver(serio);
+	if (retval)
+		return retval;
+
+	psmouse = serio_get_drvdata(serio);
+	priv = psmouse->private;
+
+	if (val == priv->powered)
+		goto done;
+
+	/* hgpk_toggle_power will deal w/ state so we're not racing w/ irq */
+	retval = hgpk_toggle_power(psmouse, val);
+	if (!retval)
+		priv->powered = val;
+
+done:
+	serio_unpin_driver(serio);
+	return retval ? retval : count;
+}
+
+static DEVICE_ATTR(powered, S_IWUSR | S_IRUGO, hgpk_show_powered,
+		hgpk_set_powered);
+
+static void hgpk_disconnect(struct psmouse *psmouse)
+{
+	struct hgpk_data *priv = psmouse->private;
+
+	device_remove_file(&psmouse->ps2dev.serio->dev, &dev_attr_powered);
+	psmouse_reset(psmouse);
+	flush_scheduled_work();
+	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,
+			&dev_attr_powered);
+	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;
+}
diff --git a/drivers/input/mouse/hgpk.h b/drivers/input/mouse/hgpk.h
new file mode 100644
index 0000000..2b1f074
--- /dev/null
+++ b/drivers/input/mouse/hgpk.h
@@ -0,0 +1,48 @@
+/*
+ * OLPC HGPK (XO-1) touchpad PS/2 mouse driver
+ */
+
+#ifndef _HGPK_H
+#define _HGPK_H
+
+enum hgpk_model_t {
+	HGPK_MODEL_PREA = 0x0a,	/* pre-B1s */
+	HGPK_MODEL_A = 0x14,	/* found on B1s, PT disabled in hardware */
+	HGPK_MODEL_B = 0x28,	/* B2s, has capacitance issues */
+	HGPK_MODEL_C = 0x3c,
+	HGPK_MODEL_D = 0x50,	/* C1, mass production */
+};
+
+struct hgpk_data {
+	struct psmouse *psmouse;
+	int powered;
+	unsigned long recalib_window;
+	struct delayed_work recalib_wq;
+};
+
+#define hgpk_dbg(psmouse, format, arg...)		\
+	dev_dbg(&(psmouse)->ps2dev.serio->dev, format, ## arg)
+#define hgpk_err(psmouse, format, arg...)		\
+	dev_err(&(psmouse)->ps2dev.serio->dev, format, ## arg)
+#define hgpk_info(psmouse, format, arg...)		\
+	dev_info(&(psmouse)->ps2dev.serio->dev, format, ## arg)
+#define hgpk_warn(psmouse, format, arg...)		\
+	dev_warn(&(psmouse)->ps2dev.serio->dev, format, ## arg)
+#define hgpk_notice(psmouse, format, arg...)		\
+	dev_notice(&(psmouse)->ps2dev.serio->dev, format, ## arg)
+
+#ifdef CONFIG_MOUSE_PS2_OLPC
+int hgpk_detect(struct psmouse *psmouse, int set_properties);
+int hgpk_init(struct psmouse *psmouse);
+#else
+static inline int hgpk_detect(struct psmouse *psmouse, int set_properties)
+{
+	return -ENODEV;
+}
+static inline int hgpk_init(struct psmouse *psmouse)
+{
+	return -ENODEV;
+}
+#endif
+
+#endif
diff --git a/drivers/input/mouse/psmouse-base.c b/drivers/input/mouse/psmouse-base.c
index 488ba95..2864678 100644
--- a/drivers/input/mouse/psmouse-base.c
+++ b/drivers/input/mouse/psmouse-base.c
@@ -25,6 +25,7 @@
 #include "synaptics.h"
 #include "logips2pp.h"
 #include "alps.h"
+#include "hgpk.h"
 #include "lifebook.h"
 #include "trackpoint.h"
 #include "touchkit_ps2.h"
@@ -636,8 +637,20 @@ static int psmouse_extensions(struct psmouse *psmouse,
 		}
 	}
 
-	if (max_proto > PSMOUSE_IMEX) {
+/*
+ * Try OLPC HGPK touchpad.
+ */
+	if (max_proto > PSMOUSE_IMEX &&
+			hgpk_detect(psmouse, set_properties) == 0) {
+		if (!set_properties || hgpk_init(psmouse) == 0)
+			return PSMOUSE_HGPK;
+/*
+ * Init failed, try basic relative protocols
+ */
+		max_proto = PSMOUSE_IMEX;
+	}
 
+	if (max_proto > PSMOUSE_IMEX) {
 		if (genius_detect(psmouse, set_properties) == 0)
 			return PSMOUSE_GENPS;
 
@@ -768,6 +781,14 @@ static const struct psmouse_protocol psmouse_protocols[] = {
 		.detect		= touchkit_ps2_detect,
 	},
 #endif
+#ifdef CONFIG_MOUSE_PS2_OLPC
+	{
+		.type		= PSMOUSE_HGPK,
+		.name		= "OLPC HGPK",
+		.alias		= "hgpk",
+		.detect		= hgpk_detect,
+	},
+#endif
 	{
 		.type		= PSMOUSE_CORTRON,
 		.name		= "CortronPS/2",
diff --git a/drivers/input/mouse/psmouse.h b/drivers/input/mouse/psmouse.h
index 48e0112..dfdc89d 100644
--- a/drivers/input/mouse/psmouse.h
+++ b/drivers/input/mouse/psmouse.h
@@ -89,6 +89,7 @@ enum psmouse_type {
 	PSMOUSE_TRACKPOINT,
 	PSMOUSE_TOUCHKIT_PS2,
 	PSMOUSE_CORTRON,
+	PSMOUSE_HGPK,
 	PSMOUSE_AUTO		/* This one should always be last */
 };
 
@@ -99,7 +100,6 @@ int psmouse_reset(struct psmouse *psmouse);
 void psmouse_set_state(struct psmouse *psmouse, enum psmouse_state new_state);
 void psmouse_set_resolution(struct psmouse *psmouse, unsigned int resolution);
 
-
 struct psmouse_attribute {
 	struct device_attribute dattr;
 	void *data;
-- 
1.5.6.3

Re: [PATCH 3/3] OLPC: touchpad driver (take 2)

[Dmitry Torokhov]

Hi Andres,

On Wed, Aug 13, 2008 at 03:24:59PM -0400, Andres Salomon wrote:
> 
> This adds support for OLPC's touchpad.  It has lots of neat features,
> none of which are enabled because the hardware is too buggy.  Instead,
> we use it like a normal touchpad, but with a number of workarounds in
> place to deal with the frequent hardware spasms.  Humidity changes,
> sweat, tinfoil underwear, plugging in AC, drinks, evil felines.. All
> tend to cause the touchpad to freak out.
> 
> Stuff like this keeps me from getting bored.
> 
> We make use of psmouse_set_state and psmouse_queue_work quite a bit.
> 
> (also, extension renamed from olpc.c to hgpk.c)
> 

Whoo-hoo, thanks!

> Signed-off-by: Andres Salomon <dilinger@debian.org>
> ---
>  drivers/input/mouse/Kconfig        |   10 +
>  drivers/input/mouse/Makefile       |    1 +
>  drivers/input/mouse/hgpk.c         |  492 ++++++++++++++++++++++++++++++++++++
>  drivers/input/mouse/hgpk.h         |   48 ++++
>  drivers/input/mouse/psmouse-base.c |   23 ++-
>  drivers/input/mouse/psmouse.h      |    2 +-
>  6 files changed, 574 insertions(+), 2 deletions(-)
>  create mode 100644 drivers/input/mouse/hgpk.c
>  create mode 100644 drivers/input/mouse/hgpk.h
> 
> diff --git a/drivers/input/mouse/Kconfig b/drivers/input/mouse/Kconfig
> index 7bbea09..fff0253 100644
> --- a/drivers/input/mouse/Kconfig
> +++ b/drivers/input/mouse/Kconfig
> @@ -96,6 +96,16 @@ config MOUSE_PS2_TOUCHKIT
>  
>  	  If unsure, say N.
>  
> +config MOUSE_PS2_OLPC
> +	bool "OLPC PS/2 mouse protocol extension"
> +	depends on MOUSE_PS2 && OLPC
> +	help
> +	  Say Y here if you have an OLPC XO-1 laptop (with built-in
> +	  PS/2 touchpad/tablet device).  The manufacturer calls the
> +	  touchpad an HGPK.
> +
> +	  If unsure, say N.
> +
>  config MOUSE_SERIAL
>  	tristate "Serial mouse"
>  	select SERIO
> diff --git a/drivers/input/mouse/Makefile b/drivers/input/mouse/Makefile
> index 9e6e363..799aa3f 100644
> --- a/drivers/input/mouse/Makefile
> +++ b/drivers/input/mouse/Makefile
> @@ -24,3 +24,4 @@ psmouse-$(CONFIG_MOUSE_PS2_LOGIPS2PP)	+= logips2pp.o
>  psmouse-$(CONFIG_MOUSE_PS2_LIFEBOOK)	+= lifebook.o
>  psmouse-$(CONFIG_MOUSE_PS2_TRACKPOINT)	+= trackpoint.o
>  psmouse-$(CONFIG_MOUSE_PS2_TOUCHKIT)	+= touchkit_ps2.o
> +psmouse-$(CONFIG_MOUSE_PS2_OLPC)	+= hgpk.o
> diff --git a/drivers/input/mouse/hgpk.c b/drivers/input/mouse/hgpk.c
> new file mode 100644
> index 0000000..ac7c2a8
> --- /dev/null
> +++ b/drivers/input/mouse/hgpk.c
> @@ -0,0 +1,492 @@
> +/*
> + * 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;
> +	static int count;
> +	static int x_tally;
> +	static int y_tally;

Hmm, I guess we'll never see 2 such devices in one box, but still moving
it to psmouse->private woudl be a good practice.

> +
> +static int hgpk_reconnect(struct psmouse *psmouse)
> +{
> +	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;

We should not return success if we can't detect the same hardware. I
think if olpc_board_at_least(olpc_board(0xb2) fails we need to return
-1;

> +}
> +
> +static ssize_t hgpk_show_powered(struct device *dev,
> +		struct device_attribute *attr, char *buf)
> +{
> +	struct serio *serio = to_serio_port(dev);
> +	struct psmouse *psmouse;
> +	struct hgpk_data *priv;
> +	int retval;
> +
> +	retval = serio_pin_driver(serio);
> +	if (retval)
> +		return retval;
> +
> +	psmouse = serio_get_drvdata(serio);
> +	priv = psmouse->private;
> +
> +	retval = sprintf(buf, "%d\n", priv->powered);
> +	serio_unpin_driver(serio);
> +	return retval;
> +}
> +
> +static ssize_t hgpk_set_powered(struct device *dev,
> +		struct device_attribute *attr, const char *buf, size_t count)
> +{
> +	struct serio *serio = to_serio_port(dev);
> +	struct psmouse *psmouse;
> +	struct hgpk_data *priv;
> +	unsigned long val;
> +	int retval;
> +
> +	if (*buf == '1')
> +		val = 1;
> +	else if (*buf == '0')
> +		val = 0;
> +	else
> +		return -EINVAL;

I'd use strict_strtoul() and checked for val <= 1.

> +
> +	retval = serio_pin_driver(serio);
> +	if (retval)
> +		return retval;
> +
> +	psmouse = serio_get_drvdata(serio);
> +	priv = psmouse->private;
> +
> +	if (val == priv->powered)
> +		goto done;
> +
> +	/* hgpk_toggle_power will deal w/ state so we're not racing w/ irq */
> +	retval = hgpk_toggle_power(psmouse, val);
> +	if (!retval)
> +		priv->powered = val;
> +
> +done:
> +	serio_unpin_driver(serio);
> +	return retval ? retval : count;
> +}
> +
> +static DEVICE_ATTR(powered, S_IWUSR | S_IRUGO, hgpk_show_powered,
> +		hgpk_set_powered);
> 

Any particular reason you didn't use PSMOUSE_DEFINE_ATTR? Then you would
not need to bother with pinning the driver and provode mutual exclusion
with other things. Btw, what do we do if device is powered down an user
tries to change some settings via generic attributes defined in
psmouse-base?

+
> +static void hgpk_disconnect(struct psmouse *psmouse)
> +{
> +	struct hgpk_data *priv = psmouse->private;
> +
> +	device_remove_file(&psmouse->ps2dev.serio->dev, &dev_attr_powered);
> +	psmouse_reset(psmouse);
> +	flush_scheduled_work();

What does this flush protect from? We are using specialized workqueue.
Plus psmouse_disconnect should take care of this, shouldn't it?

> +	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");
> +}
> +

Overall I am concerned about mutual exclusions between operations, such
as settin power state and adjusting genericmouse  properties (repeaqt
rate, resolution, etc). Psmouse-base usues psmouse_mutex for that, mayne
olps should do that too...

-- 
Dmitry

Re: [PATCH 3/3] OLPC: touchpad driver (take 2)

[Andres Salomon]

Hi Dmitry,

Sorry, just now getting the chance to look at this...

On Thu, 14 Aug 2008 23:14:35 -0400
Dmitry Torokhov <dmitry.torokhov@gmail.com> wrote:

> Hi Andres,
> 
[...]
> > +
> > +/*
> > + * 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;
> > +	static int count;
> > +	static int x_tally;
> > +	static int y_tally;
> 
> Hmm, I guess we'll never see 2 such devices in one box, but still
> moving it to psmouse->private woudl be a good practice.


Can you please clarify this comment?


> 
> > +
> > +static int hgpk_reconnect(struct psmouse *psmouse)
> > +{
> > +	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;
> 
> We should not return success if we can't detect the same hardware. I
> think if olpc_board_at_least(olpc_board(0xb2) fails we need to return
> -1;
> 

This check isn't any kind of failure; it's due to a hardware quirk with
earlier prototypes.  Basically, during suspend/resume, the touchpad
rails stay powered.  We don't want to do any sort of reset of the
psmouse device, otherwise we lose data (especially if someone is waking
up the device via touchpad usage or button press, we certainly don't
want to reset and drop the packets).

However, b1 hardware required a reset for reasons that I can't recall
anymore.  In both cases, the reconnect worked just fine; the difference
is that a psmouse_reset was issued for b2 hardware and higher.

I suppose the code should have a comment saying just that, eh? :)

> > +}
> > +
> > +static ssize_t hgpk_show_powered(struct device *dev,
> > +		struct device_attribute *attr, char *buf)
> > +{
> > +	struct serio *serio = to_serio_port(dev);
> > +	struct psmouse *psmouse;
> > +	struct hgpk_data *priv;
> > +	int retval;
> > +
> > +	retval = serio_pin_driver(serio);
> > +	if (retval)
> > +		return retval;
> > +
> > +	psmouse = serio_get_drvdata(serio);
> > +	priv = psmouse->private;
> > +
> > +	retval = sprintf(buf, "%d\n", priv->powered);
> > +	serio_unpin_driver(serio);
> > +	return retval;
> > +}
> > +
> > +static ssize_t hgpk_set_powered(struct device *dev,
> > +		struct device_attribute *attr, const char *buf,
> > size_t count) +{
> > +	struct serio *serio = to_serio_port(dev);
> > +	struct psmouse *psmouse;
> > +	struct hgpk_data *priv;
> > +	unsigned long val;
> > +	int retval;
> > +
> > +	if (*buf == '1')
> > +		val = 1;
> > +	else if (*buf == '0')
> > +		val = 0;
> > +	else
> > +		return -EINVAL;
> 
> I'd use strict_strtoul() and checked for val <= 1.
> 

*nod*

> > +
> > +	retval = serio_pin_driver(serio);
> > +	if (retval)
> > +		return retval;
> > +
> > +	psmouse = serio_get_drvdata(serio);
> > +	priv = psmouse->private;
> > +
> > +	if (val == priv->powered)
> > +		goto done;
> > +
> > +	/* hgpk_toggle_power will deal w/ state so we're not
> > racing w/ irq */
> > +	retval = hgpk_toggle_power(psmouse, val);
> > +	if (!retval)
> > +		priv->powered = val;
> > +
> > +done:
> > +	serio_unpin_driver(serio);
> > +	return retval ? retval : count;
> > +}
> > +
> > +static DEVICE_ATTR(powered, S_IWUSR | S_IRUGO, hgpk_show_powered,
> > +		hgpk_set_powered);
> > 
> 
> Any particular reason you didn't use PSMOUSE_DEFINE_ATTR? Then you

PSMOUSE_DEFINE_ATTR is fine for show_powered, but doesn't work for
set_powered because it
a) doesn't change the value if psmouse->state == PSMOUSE_IGNORE
b) does some deactivation dance/activate dance

I don't remember the specifics, but our powered stuff wasn't working as
a PSMOUSE_DEFINE_ATTR callback.  At some point soon I'll take another
look at it and see what the specific problem was.

> would not need to bother with pinning the driver and provode mutual
> exclusion with other things. Btw, what do we do if device is powered

Agreed, the mutex stuff is not ideal.

> down an user tries to change some settings via generic attributes
> defined in psmouse-base?
> 

Hm, good point; set_powered should be setting PSMOUSE_IGNORE when
powering the device off!

> +
> > +static void hgpk_disconnect(struct psmouse *psmouse)
> > +{
> > +	struct hgpk_data *priv = psmouse->private;
> > +
> > +	device_remove_file(&psmouse->ps2dev.serio->dev,
> > &dev_attr_powered);
> > +	psmouse_reset(psmouse);
> > +	flush_scheduled_work();
> 
> What does this flush protect from? We are using specialized workqueue.
> Plus psmouse_disconnect should take care of this, shouldn't it?
>

According to the commit I made some time ago, it's to protect against
a race with kpsmouse_wq that would cause an oops.  I don't actually
know if I was being paranoid there, or if there actually _was_ an oops
that was being triggered.

You're right though, psmouse_disconnect should take care of it for us..
 
> > +	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");
> > +}
> > +
> 
> Overall I am concerned about mutual exclusions between operations,
> such as settin power state and adjusting genericmouse  properties
> (repeaqt rate, resolution, etc). Psmouse-base usues psmouse_mutex for
> that, mayne olps should do that too...
> 

*nod*, I'll see what I can do about the powered thing.  Thanks!

Re: [PATCH 3/3] OLPC: touchpad driver (take 2)

[Dmitry Torokhov]

On Fri, Aug 29, 2008 at 02:49:59AM -0400, Andres Salomon wrote:
> > > +static void hgpk_spewing_hack(struct psmouse *psmouse, int l, int
> > > r, int x,
> > > +		int y)
> > > +{
> > > +	struct hgpk_data *priv = psmouse->private;
> > > +	static int count;
> > > +	static int x_tally;
> > > +	static int y_tally;
> > 
> > Hmm, I guess we'll never see 2 such devices in one box, but still
> > moving it to psmouse->private woudl be a good practice.
> 
> 
> Can you please clarify this comment?
> 

If you ever have 2 such devices in the same box use of static variables
will cause the code to not work properly because they will be shared
between the devices. Proper way is to move them into per-device
structure.

-- 
Dmitry

Re: [PATCH 3/3] OLPC: touchpad driver (take 2)

[Andres Salomon]

On Thu, 14 Aug 2008 23:14:35 -0400
Dmitry Torokhov <dmitry.torokhov@gmail.com> wrote:

> Hi Andres,
> 
> On Wed, Aug 13, 2008 at 03:24:59PM -0400, Andres Salomon wrote:
[...]
> 
> > +
> > +	retval = serio_pin_driver(serio);
> > +	if (retval)
> > +		return retval;
> > +
> > +	psmouse = serio_get_drvdata(serio);
> > +	priv = psmouse->private;
> > +
> > +	if (val == priv->powered)
> > +		goto done;
> > +
> > +	/* hgpk_toggle_power will deal w/ state so we're not
> > racing w/ irq */
> > +	retval = hgpk_toggle_power(psmouse, val);
> > +	if (!retval)
> > +		priv->powered = val;
> > +
> > +done:
> > +	serio_unpin_driver(serio);
> > +	return retval ? retval : count;
> > +}
> > +
> > +static DEVICE_ATTR(powered, S_IWUSR | S_IRUGO, hgpk_show_powered,
> > +		hgpk_set_powered);
> > 
> 
> Any particular reason you didn't use PSMOUSE_DEFINE_ATTR? Then you
> would not need to bother with pinning the driver and provode mutual
> exclusion with other things. Btw, what do we do if device is powered
> down an user tries to change some settings via generic attributes
> defined in psmouse-base?
> 

Ok, the problem is this - hgpk_set_powered disables power by sending a
special command, and power is re-enabled with the following code:

                /*
                 * 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);
                }

This means that after telling the ALPS device to turn off power, we
shouldn't be sending any ps2 commands until we want to turn power
back on.  However, psmouse_attr_set_helper code has the following:

        psmouse_deactivate(psmouse);
        retval = attr->set(psmouse, attr->data, buf, count);
        if (retval != -ENODEV)
                psmouse_activate(psmouse);

If we're disabling power, psmouse_activate will proceed to turn
power back on.

There's also the following check in psmouse_attr_set_helper:

        if (psmouse->state == PSMOUSE_IGNORE) {
                retval = -ENODEV;
                goto out_unlock;
        }

That's not at all what we want; when we disable power, we also
do a psmouse_set_state(psmouse, PSMOUSE_IGNORE).  That check
means we'd never be able to turn power back on.


What do you think about either changing PSMOUSE_DEFINE_ATTR
to take an additional 'raw' argument (meaning psmouse->state is
not checked, and psmouse_deactivate/psmouse_activate are not
called), or alternatively adding new helper functions that just
handle the locking (__PSMOUSE_DEFINE_ATTR() and
__psmouse_attr_{set,show}_helper())?  I'd prefer the raw
argument.

Re: [PATCH 3/3] OLPC: touchpad driver (take 2)

[Andres Salomon]

On Wed, 10 Sep 2008 17:55:13 -0400
Andres Salomon <dilinger@queued.net> wrote:
[...]
> 
> 
> What do you think about either changing PSMOUSE_DEFINE_ATTR
> to take an additional 'raw' argument (meaning psmouse->state is
> not checked, and psmouse_deactivate/psmouse_activate are not
> called), or alternatively adding new helper functions that just
> handle the locking (__PSMOUSE_DEFINE_ATTR() and
> __psmouse_attr_{set,show}_helper())?  I'd prefer the raw
> argument.

Ie, something like this (I'll resend all patches later if you approve).


>From f009e1d3da0266ec99437c243482026c96c9103c Mon Sep 17 00:00:00 2001
From: Andres Salomon <dilinger@debian.org>
Date: Thu, 11 Sep 2008 00:38:02 -0400
Subject: [PATCH] psmouse: tweak PSMOUSE_DEFINE_ATTR to support raw set callbacks

We want to support attr->set callbacks that may need psmouse->state to
not be updated, or may want to manually deal w/ enabling and disabling
the device.  As such, add a variable to PSMOUSE_DEFINE_ATTR that
determines whether or not we protect the set callback with state
updating.

Signed-off-by: Andres Salomon <dilinger@debian.org>
---
 drivers/input/mouse/logips2pp.c    |    2 +-
 drivers/input/mouse/psmouse-base.c |   40 +++++++++++++++++++----------------
 drivers/input/mouse/psmouse.h      |    4 ++-
 drivers/input/mouse/trackpoint.c   |    4 +-
 4 files changed, 28 insertions(+), 22 deletions(-)

diff --git a/drivers/input/mouse/logips2pp.c b/drivers/input/mouse/logips2pp.c
index 0c5660d..010294f 100644
--- a/drivers/input/mouse/logips2pp.c
+++ b/drivers/input/mouse/logips2pp.c
@@ -168,7 +168,7 @@ static ssize_t ps2pp_attr_set_smartscroll(struct psmouse *psmouse, void *data, c
 	return count;
 }
 
-PSMOUSE_DEFINE_ATTR(smartscroll, S_IWUSR | S_IRUGO, NULL,
+PSMOUSE_DEFINE_ATTR(smartscroll, S_IWUSR | S_IRUGO, NULL, 1,
 			ps2pp_attr_show_smartscroll, ps2pp_attr_set_smartscroll);
 
 /*
diff --git a/drivers/input/mouse/psmouse-base.c b/drivers/input/mouse/psmouse-base.c
index 488ba95..3e13059 100644
--- a/drivers/input/mouse/psmouse-base.c
+++ b/drivers/input/mouse/psmouse-base.c
@@ -65,20 +65,20 @@ module_param_named(resync_time, psmouse_resync_time, uint, 0644);
 MODULE_PARM_DESC(resync_time, "How long can mouse stay idle before forcing resync (in seconds, 0 = never).");
 
 PSMOUSE_DEFINE_ATTR(protocol, S_IWUSR | S_IRUGO,
-			NULL,
+			NULL, 1,
 			psmouse_attr_show_protocol, psmouse_attr_set_protocol);
 PSMOUSE_DEFINE_ATTR(rate, S_IWUSR | S_IRUGO,
 			(void *) offsetof(struct psmouse, rate),
-			psmouse_show_int_attr, psmouse_attr_set_rate);
+			1, psmouse_show_int_attr, psmouse_attr_set_rate);
 PSMOUSE_DEFINE_ATTR(resolution, S_IWUSR | S_IRUGO,
 			(void *) offsetof(struct psmouse, resolution),
-			psmouse_show_int_attr, psmouse_attr_set_resolution);
+			1, psmouse_show_int_attr, psmouse_attr_set_resolution);
 PSMOUSE_DEFINE_ATTR(resetafter, S_IWUSR | S_IRUGO,
 			(void *) offsetof(struct psmouse, resetafter),
-			psmouse_show_int_attr, psmouse_set_int_attr);
+			1, psmouse_show_int_attr, psmouse_set_int_attr);
 PSMOUSE_DEFINE_ATTR(resync_time, S_IWUSR | S_IRUGO,
 			(void *) offsetof(struct psmouse, resync_time),
-			psmouse_show_int_attr, psmouse_set_int_attr);
+			1, psmouse_show_int_attr, psmouse_set_int_attr);
 
 static struct attribute *psmouse_attributes[] = {
 	&psmouse_attr_protocol.dattr.attr,
@@ -1401,25 +1401,29 @@ ssize_t psmouse_attr_set_helper(struct device *dev, struct device_attribute *dev
 
 	psmouse = serio_get_drvdata(serio);
 
-	if (psmouse->state == PSMOUSE_IGNORE) {
-		retval = -ENODEV;
-		goto out_unlock;
-	}
+	if (attr->protected_set) {
+		if (psmouse->state == PSMOUSE_IGNORE) {
+			retval = -ENODEV;
+			goto out_unlock;
+		}
 
-	if (serio->parent && serio->id.type == SERIO_PS_PSTHRU) {
-		parent = serio_get_drvdata(serio->parent);
-		psmouse_deactivate(parent);
-	}
+		if (serio->parent && serio->id.type == SERIO_PS_PSTHRU) {
+			parent = serio_get_drvdata(serio->parent);
+			psmouse_deactivate(parent);
+		}
 
-	psmouse_deactivate(psmouse);
+		psmouse_deactivate(psmouse);
+	}
 
 	retval = attr->set(psmouse, attr->data, buf, count);
 
-	if (retval != -ENODEV)
-		psmouse_activate(psmouse);
+	if (attr->protected_set) {
+		if (retval != -ENODEV)
+			psmouse_activate(psmouse);
 
-	if (parent)
-		psmouse_activate(parent);
+		if (parent)
+			psmouse_activate(parent);
+	}
 
  out_unlock:
 	mutex_unlock(&psmouse_mutex);
diff --git a/drivers/input/mouse/psmouse.h b/drivers/input/mouse/psmouse.h
index 48e0112..184ba43 100644
--- a/drivers/input/mouse/psmouse.h
+++ b/drivers/input/mouse/psmouse.h
@@ -106,6 +106,7 @@ struct psmouse_attribute {
 	ssize_t (*show)(struct psmouse *psmouse, void *data, char *buf);
 	ssize_t (*set)(struct psmouse *psmouse, void *data,
 			const char *buf, size_t count);
+	int protected_set;
 };
 #define to_psmouse_attr(a)	container_of((a), struct psmouse_attribute, dattr)
 
@@ -114,7 +115,7 @@ ssize_t psmouse_attr_show_helper(struct device *dev, struct device_attribute *at
 ssize_t psmouse_attr_set_helper(struct device *dev, struct device_attribute *attr,
 				const char *buf, size_t count);
 
-#define PSMOUSE_DEFINE_ATTR(_name, _mode, _data, _show, _set)			\
+#define PSMOUSE_DEFINE_ATTR(_name, _mode, _data, _protected_set, _show, _set)	\
 static ssize_t _show(struct psmouse *, void *data, char *);			\
 static ssize_t _set(struct psmouse *, void *data, const char *, size_t);	\
 static struct psmouse_attribute psmouse_attr_##_name = {			\
@@ -129,6 +130,7 @@ static struct psmouse_attribute psmouse_attr_##_name = {			\
 	.data	= _data,							\
 	.show	= _show,							\
 	.set	= _set,								\
+	.protected_set = _protected_set,					\
 }
 
 #endif /* _PSMOUSE_H */
diff --git a/drivers/input/mouse/trackpoint.c b/drivers/input/mouse/trackpoint.c
index 26b845f..156d2f6 100644
--- a/drivers/input/mouse/trackpoint.c
+++ b/drivers/input/mouse/trackpoint.c
@@ -107,7 +107,7 @@ static ssize_t trackpoint_set_int_attr(struct psmouse *psmouse, void *data,
 		.command = _command,						\
 	};									\
 	PSMOUSE_DEFINE_ATTR(_name, S_IWUSR | S_IRUGO,				\
-			    &trackpoint_attr_##_name,				\
+			    &trackpoint_attr_##_name, 1,			\
 			    trackpoint_show_int_attr, trackpoint_set_int_attr)
 
 static ssize_t trackpoint_set_bit_attr(struct psmouse *psmouse, void *data,
@@ -143,7 +143,7 @@ static ssize_t trackpoint_set_bit_attr(struct psmouse *psmouse, void *data,
 		.inverted	= _inv,						\
 	};									\
 	PSMOUSE_DEFINE_ATTR(_name, S_IWUSR | S_IRUGO,				\
-			    &trackpoint_attr_##_name,				\
+			    &trackpoint_attr_##_name, 1,			\
 			    trackpoint_show_int_attr, trackpoint_set_bit_attr)
 
 TRACKPOINT_INT_ATTR(sensitivity, TP_SENS);
-- 
1.5.6.5

Re: [PATCH 3/3] OLPC: touchpad driver (take 2)

[Andres Salomon]

On Thu, 11 Sep 2008 01:01:24 -0400
Andres Salomon <dilinger@queued.net> wrote:

> On Wed, 10 Sep 2008 17:55:13 -0400
> Andres Salomon <dilinger@queued.net> wrote:
> [...]
> > 
> > 
> > What do you think about either changing PSMOUSE_DEFINE_ATTR
> > to take an additional 'raw' argument (meaning psmouse->state is
> > not checked, and psmouse_deactivate/psmouse_activate are not
> > called), or alternatively adding new helper functions that just
> > handle the locking (__PSMOUSE_DEFINE_ATTR() and
> > __psmouse_attr_{set,show}_helper())?  I'd prefer the raw
> > argument.
> 
> Ie, something like this (I'll resend all patches later if you
> approve).
> 

And here's the current touchpad driver after updating based upon your
comments.

diff --git a/drivers/input/mouse/Kconfig b/drivers/input/mouse/Kconfig
index 7bbea09..fff0253 100644
--- a/drivers/input/mouse/Kconfig
+++ b/drivers/input/mouse/Kconfig
@@ -96,6 +96,16 @@ config MOUSE_PS2_TOUCHKIT
 
 	  If unsure, say N.
 
+config MOUSE_PS2_OLPC
+	bool "OLPC PS/2 mouse protocol extension"
+	depends on MOUSE_PS2 && OLPC
+	help
+	  Say Y here if you have an OLPC XO-1 laptop (with built-in
+	  PS/2 touchpad/tablet device).  The manufacturer calls the
+	  touchpad an HGPK.
+
+	  If unsure, say N.
+
 config MOUSE_SERIAL
 	tristate "Serial mouse"
 	select SERIO
diff --git a/drivers/input/mouse/Makefile b/drivers/input/mouse/Makefile
index 9e6e363..799aa3f 100644
--- a/drivers/input/mouse/Makefile
+++ b/drivers/input/mouse/Makefile
@@ -24,3 +24,4 @@ psmouse-$(CONFIG_MOUSE_PS2_LOGIPS2PP)	+= logips2pp.o
 psmouse-$(CONFIG_MOUSE_PS2_LIFEBOOK)	+= lifebook.o
 psmouse-$(CONFIG_MOUSE_PS2_TRACKPOINT)	+= trackpoint.o
 psmouse-$(CONFIG_MOUSE_PS2_TOUCHKIT)	+= touchkit_ps2.o
+psmouse-$(CONFIG_MOUSE_PS2_OLPC)	+= hgpk.o
diff --git a/drivers/input/mouse/hgpk.c b/drivers/input/mouse/hgpk.c
new file mode 100644
index 0000000..c8cba1b
--- /dev/null
+++ b/drivers/input/mouse/hgpk.c
@@ -0,0 +1,470 @@
+/*
+ * 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->count++;
+	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)
+{
+	if (!(packet[0] & (1<<3)) || (packet[0] & (1<<2)))
+		return -1;
+
+	return 0;
+}
+
+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;
+
+	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;
+	unsigned long value;
+	int err;
+
+	err = strict_strtoul(buf, 10, &value);
+	if (err || value > 1)
+		return -EINVAL;
+
+	priv = psmouse->private;
+	if (value == priv->powered)
+		return 0;
+
+	/* 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, 0, hgpk_show_powered,
+		hgpk_set_powered);
+
+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;
+}
diff --git a/drivers/input/mouse/hgpk.h b/drivers/input/mouse/hgpk.h
new file mode 100644
index 0000000..a4b2a96
--- /dev/null
+++ b/drivers/input/mouse/hgpk.h
@@ -0,0 +1,49 @@
+/*
+ * OLPC HGPK (XO-1) touchpad PS/2 mouse driver
+ */
+
+#ifndef _HGPK_H
+#define _HGPK_H
+
+enum hgpk_model_t {
+	HGPK_MODEL_PREA = 0x0a,	/* pre-B1s */
+	HGPK_MODEL_A = 0x14,	/* found on B1s, PT disabled in hardware */
+	HGPK_MODEL_B = 0x28,	/* B2s, has capacitance issues */
+	HGPK_MODEL_C = 0x3c,
+	HGPK_MODEL_D = 0x50,	/* C1, mass production */
+};
+
+struct hgpk_data {
+	struct psmouse *psmouse;
+	int powered;
+	int count, x_tally, y_tally;	/* hardware workaround stuff */
+	unsigned long recalib_window;
+	struct delayed_work recalib_wq;
+};
+
+#define hgpk_dbg(psmouse, format, arg...)		\
+	dev_dbg(&(psmouse)->ps2dev.serio->dev, format, ## arg)
+#define hgpk_err(psmouse, format, arg...)		\
+	dev_err(&(psmouse)->ps2dev.serio->dev, format, ## arg)
+#define hgpk_info(psmouse, format, arg...)		\
+	dev_info(&(psmouse)->ps2dev.serio->dev, format, ## arg)
+#define hgpk_warn(psmouse, format, arg...)		\
+	dev_warn(&(psmouse)->ps2dev.serio->dev, format, ## arg)
+#define hgpk_notice(psmouse, format, arg...)		\
+	dev_notice(&(psmouse)->ps2dev.serio->dev, format, ## arg)
+
+#ifdef CONFIG_MOUSE_PS2_OLPC
+int hgpk_detect(struct psmouse *psmouse, int set_properties);
+int hgpk_init(struct psmouse *psmouse);
+#else
+static inline int hgpk_detect(struct psmouse *psmouse, int set_properties)
+{
+	return -ENODEV;
+}
+static inline int hgpk_init(struct psmouse *psmouse)
+{
+	return -ENODEV;
+}
+#endif
+
+#endif
diff --git a/drivers/input/mouse/psmouse-base.c b/drivers/input/mouse/psmouse-base.c
index 3e13059..793cae9 100644
--- a/drivers/input/mouse/psmouse-base.c
+++ b/drivers/input/mouse/psmouse-base.c
@@ -25,6 +25,7 @@
 #include "synaptics.h"
 #include "logips2pp.h"
 #include "alps.h"
+#include "hgpk.h"
 #include "lifebook.h"
 #include "trackpoint.h"
 #include "touchkit_ps2.h"
@@ -636,8 +637,20 @@ static int psmouse_extensions(struct psmouse *psmouse,
 		}
 	}
 
-	if (max_proto > PSMOUSE_IMEX) {
+/*
+ * Try OLPC HGPK touchpad.
+ */
+	if (max_proto > PSMOUSE_IMEX &&
+			hgpk_detect(psmouse, set_properties) == 0) {
+		if (!set_properties || hgpk_init(psmouse) == 0)
+			return PSMOUSE_HGPK;
+/*
+ * Init failed, try basic relative protocols
+ */
+		max_proto = PSMOUSE_IMEX;
+	}
 
+	if (max_proto > PSMOUSE_IMEX) {
 		if (genius_detect(psmouse, set_properties) == 0)
 			return PSMOUSE_GENPS;
 
@@ -768,6 +781,14 @@ static const struct psmouse_protocol psmouse_protocols[] = {
 		.detect		= touchkit_ps2_detect,
 	},
 #endif
+#ifdef CONFIG_MOUSE_PS2_OLPC
+	{
+		.type		= PSMOUSE_HGPK,
+		.name		= "OLPC HGPK",
+		.alias		= "hgpk",
+		.detect		= hgpk_detect,
+	},
+#endif
 	{
 		.type		= PSMOUSE_CORTRON,
 		.name		= "CortronPS/2",
diff --git a/drivers/input/mouse/psmouse.h b/drivers/input/mouse/psmouse.h
index 184ba43..1d73fee 100644
--- a/drivers/input/mouse/psmouse.h
+++ b/drivers/input/mouse/psmouse.h
@@ -89,6 +89,7 @@ enum psmouse_type {
 	PSMOUSE_TRACKPOINT,
 	PSMOUSE_TOUCHKIT_PS2,
 	PSMOUSE_CORTRON,
+	PSMOUSE_HGPK,
 	PSMOUSE_AUTO		/* This one should always be last */
 };
 
@@ -99,7 +100,6 @@ int psmouse_reset(struct psmouse *psmouse);
 void psmouse_set_state(struct psmouse *psmouse, enum psmouse_state new_state);
 void psmouse_set_resolution(struct psmouse *psmouse, unsigned int resolution);
 
-
 struct psmouse_attribute {
 	struct device_attribute dattr;
 	void *data;

Re: [PATCH 3/3] OLPC: touchpad driver (take 2)

[Dmitry Torokhov]

Hi Andres,

On Thu, Sep 11, 2008 at 01:01:24AM -0400, Andres Salomon wrote:
> @@ -114,7 +115,7 @@ ssize_t psmouse_attr_show_helper(struct device *dev, struct device_attribute *at
>  ssize_t psmouse_attr_set_helper(struct device *dev, struct device_attribute *attr,
>  				const char *buf, size_t count);
>  
> -#define PSMOUSE_DEFINE_ATTR(_name, _mode, _data, _show, _set)			\
> +#define PSMOUSE_DEFINE_ATTR(_name, _mode, _data, _protected_set, _show, _set)	\
>  static ssize_t _show(struct psmouse *, void *data, char *);			\
>  static ssize_t _set(struct psmouse *, void *data, const char *, size_t);	\
>  static struct psmouse_attribute psmouse_attr_##_name = {			\
> @@ -129,6 +130,7 @@ static struct psmouse_attribute psmouse_attr_##_name = {			\
>  	.data	= _data,							\
>  	.show	= _show,							\
>  	.set	= _set,								\
> +	.protected_set = _protected_set,					\
>  }
>  

I would rather you defined __PSMOUSE_DEFINE_ATTR() with 'protected'
argument and then defined PSMOUSE_DEFINE_ATTR() through underscored
version so that nothing else need to be changed.

-- 
Dmitry

Re: [PATCH 3/3] OLPC: touchpad driver (take 2)

[Dmitry Torokhov]

On Thu, Sep 11, 2008 at 01:32:09AM -0400, Andres Salomon wrote:
> 
> And here's the current touchpad driver after updating based upon your
> comments.
> 

Looks good. Care to respin it all thogether based on the attribute
change I requested so I can be sure I'm applying the latest version of
everything? Ummm....

> diff --git a/drivers/input/mouse/Kconfig b/drivers/input/mouse/Kconfig
> index 7bbea09..fff0253 100644
> --- a/drivers/input/mouse/Kconfig
> +++ b/drivers/input/mouse/Kconfig
> @@ -96,6 +96,16 @@ config MOUSE_PS2_TOUCHKIT
>  
>  	  If unsure, say N.
>  
> +config MOUSE_PS2_OLPC
> +	bool "OLPC PS/2 mouse protocol extension"
> +	depends on MOUSE_PS2 && OLPC

Are you sure it shoudl depend on OLPC? It looks like driver should
work on any box with PS/2 port. I understand that only OLPC has the
hardware installed but can this change?

Thanks!

-- 
Dmitry

Re: [PATCH 3/3] OLPC: touchpad driver (take 2)

[Andres Salomon]

On Thu, 11 Sep 2008 09:05:22 -0400
Dmitry Torokhov <dmitry.torokhov@gmail.com> wrote:

> On Thu, Sep 11, 2008 at 01:32:09AM -0400, Andres Salomon wrote:
> > 
> > And here's the current touchpad driver after updating based upon
> > your comments.
> > 
> 
> Looks good. Care to respin it all thogether based on the attribute
> change I requested so I can be sure I'm applying the latest version of
> everything? Ummm....
> 

Thanks, will do.


> > diff --git a/drivers/input/mouse/Kconfig
> > b/drivers/input/mouse/Kconfig index 7bbea09..fff0253 100644
> > --- a/drivers/input/mouse/Kconfig
> > +++ b/drivers/input/mouse/Kconfig
> > @@ -96,6 +96,16 @@ config MOUSE_PS2_TOUCHKIT
> >  
> >  	  If unsure, say N.
> >  
> > +config MOUSE_PS2_OLPC
> > +	bool "OLPC PS/2 mouse protocol extension"
> > +	depends on MOUSE_PS2 && OLPC
> 
> Are you sure it shoudl depend on OLPC? It looks like driver should
> work on any box with PS/2 port. I understand that only OLPC has the
> hardware installed but can this change?
> 
> Thanks!
> 

Positive; the majority of this driver is just workarounds for bugs in
the hardware that are specific to OLPC.  If we didn't have to
deal with flaky hardware and recalibrations, we could just
use standard psmouse without extensions.  :/

Re: [PATCH 3/3] OLPC: touchpad driver (take 2)

[Andres Salomon]

On Thu, 11 Sep 2008 09:05:22 -0400
Dmitry Torokhov <dmitry.torokhov@gmail.com> wrote:

> On Thu, Sep 11, 2008 at 01:32:09AM -0400, Andres Salomon wrote:
> > 
> > And here's the current touchpad driver after updating based upon
> > your comments.
> > 
> 
> Looks good. Care to respin it all thogether based on the attribute
> change I requested so I can be sure I'm applying the latest version of
> everything? Ummm....
> 

Here's the patch.  This is on top of the other 2 psmouse patches that
were previously sent.




From: Andres Salomon <dilinger@debian.org>
Subject: [PATCH] psmouse: tweak PSMOUSE_DEFINE_ATTR to support raw set callbacks

We want to support attr->set callbacks that may need psmouse->state to
not be updated, or may want to manually deal w/ enabling and disabling
the device.  To do that, we create __PSMOUSE_DEFINE_ATTR which enables
us to set a 'protect' argument specifying whether or not the set
callback should be protected with psmouse_disable and state setting.

Signed-off-by: Andres Salomon <dilinger@debian.org>
---
 drivers/input/mouse/psmouse-base.c |   30 +++++++++++++++++-------------
 drivers/input/mouse/psmouse.h      |    7 ++++++-
 2 files changed, 23 insertions(+), 14 deletions(-)

diff --git a/drivers/input/mouse/psmouse-base.c b/drivers/input/mouse/psmouse-base.c
index 488ba95..f7278e6 100644
--- a/drivers/input/mouse/psmouse-base.c
+++ b/drivers/input/mouse/psmouse-base.c
@@ -1401,25 +1401,29 @@ ssize_t psmouse_attr_set_helper(struct device *dev, struct device_attribute *dev
 
 	psmouse = serio_get_drvdata(serio);
 
-	if (psmouse->state == PSMOUSE_IGNORE) {
-		retval = -ENODEV;
-		goto out_unlock;
-	}
+	if (attr->protect) {
+		if (psmouse->state == PSMOUSE_IGNORE) {
+			retval = -ENODEV;
+			goto out_unlock;
+		}
 
-	if (serio->parent && serio->id.type == SERIO_PS_PSTHRU) {
-		parent = serio_get_drvdata(serio->parent);
-		psmouse_deactivate(parent);
-	}
+		if (serio->parent && serio->id.type == SERIO_PS_PSTHRU) {
+			parent = serio_get_drvdata(serio->parent);
+			psmouse_deactivate(parent);
+		}
 
-	psmouse_deactivate(psmouse);
+		psmouse_deactivate(psmouse);
+	}
 
 	retval = attr->set(psmouse, attr->data, buf, count);
 
-	if (retval != -ENODEV)
-		psmouse_activate(psmouse);
+	if (attr->protect) {
+		if (retval != -ENODEV)
+			psmouse_activate(psmouse);
 
-	if (parent)
-		psmouse_activate(parent);
+		if (parent)
+			psmouse_activate(parent);
+	}
 
  out_unlock:
 	mutex_unlock(&psmouse_mutex);
diff --git a/drivers/input/mouse/psmouse.h b/drivers/input/mouse/psmouse.h
index 48e0112..0f13c1b 100644
--- a/drivers/input/mouse/psmouse.h
+++ b/drivers/input/mouse/psmouse.h
@@ -106,6 +106,7 @@ struct psmouse_attribute {
 	ssize_t (*show)(struct psmouse *psmouse, void *data, char *buf);
 	ssize_t (*set)(struct psmouse *psmouse, void *data,
 			const char *buf, size_t count);
+	int protect;
 };
 #define to_psmouse_attr(a)	container_of((a), struct psmouse_attribute, dattr)
 
@@ -114,7 +115,7 @@ ssize_t psmouse_attr_show_helper(struct device *dev, struct device_attribute *at
 ssize_t psmouse_attr_set_helper(struct device *dev, struct device_attribute *attr,
 				const char *buf, size_t count);
 
-#define PSMOUSE_DEFINE_ATTR(_name, _mode, _data, _show, _set)			\
+#define __PSMOUSE_DEFINE_ATTR(_name, _mode, _data, _show, _set, _protect)	\
 static ssize_t _show(struct psmouse *, void *data, char *);			\
 static ssize_t _set(struct psmouse *, void *data, const char *, size_t);	\
 static struct psmouse_attribute psmouse_attr_##_name = {			\
@@ -129,6 +130,10 @@ static struct psmouse_attribute psmouse_attr_##_name = {			\
 	.data	= _data,							\
 	.show	= _show,							\
 	.set	= _set,								\
+	.protect = _protect,							\
 }
 
+#define PSMOUSE_DEFINE_ATTR(_name, _mode, _data, _show, _set)	\
+		__PSMOUSE_DEFINE_ATTR(_name, _mode, _data, _show, _set, 1)
+
 #endif /* _PSMOUSE_H */
-- 
1.5.6.5

Re: [PATCH 3/3] OLPC: touchpad driver (take 2)

[Andres Salomon]

On Thu, 11 Sep 2008 14:32:16 -0400
Andres Salomon <dilinger@queued.net> wrote:

> On Thu, 11 Sep 2008 09:05:22 -0400
> Dmitry Torokhov <dmitry.torokhov@gmail.com> wrote:
> 
> > On Thu, Sep 11, 2008 at 01:32:09AM -0400, Andres Salomon wrote:
> > > 
> > > And here's the current touchpad driver after updating based upon
> > > your comments.
> > > 
> > 
> > Looks good. Care to respin it all thogether based on the attribute
> > change I requested so I can be sure I'm applying the latest version
> > of everything? Ummm....
> > 
> 
> Here's the patch.  This is on top of the other 2 psmouse patches that
> were previously sent.
> 

And finally, here's the updated OLPC patch.



From: Andres Salomon <dilinger@debian.org>
Subject: [PATCH] OLPC: touchpad driver

This adds support for OLPC's touchpad.  It has lots of neat features,
none of which are enabled because the hardware is too buggy.  Instead,
we use it like a normal touchpad, but with a number of workarounds in
place to deal with the frequent hardware spasms.  Humidity changes,
sweat, tinfoil underwear, plugging in AC, drinks, evil felines.. All
tend to cause the touchpad to freak out.

Stuff like this keeps me from getting bored.

We make use of psmouse_set_state and psmouse_queue_work quite a bit.

Signed-off-by: Andres Salomon <dilinger@debian.org>
---
 drivers/input/mouse/Kconfig        |   10 +
 drivers/input/mouse/Makefile       |    1 +
 drivers/input/mouse/hgpk.c         |  473 ++++++++++++++++++++++++++++++++++++
 drivers/input/mouse/hgpk.h         |   49 ++++
 drivers/input/mouse/psmouse-base.c |   23 ++-
 drivers/input/mouse/psmouse.h      |    2 +-
 6 files changed, 556 insertions(+), 2 deletions(-)
 create mode 100644 drivers/input/mouse/hgpk.c
 create mode 100644 drivers/input/mouse/hgpk.h

diff --git a/drivers/input/mouse/Kconfig b/drivers/input/mouse/Kconfig
index 7bbea09..fff0253 100644
--- a/drivers/input/mouse/Kconfig
+++ b/drivers/input/mouse/Kconfig
@@ -96,6 +96,16 @@ config MOUSE_PS2_TOUCHKIT
 
 	  If unsure, say N.
 
+config MOUSE_PS2_OLPC
+	bool "OLPC PS/2 mouse protocol extension"
+	depends on MOUSE_PS2 && OLPC
+	help
+	  Say Y here if you have an OLPC XO-1 laptop (with built-in
+	  PS/2 touchpad/tablet device).  The manufacturer calls the
+	  touchpad an HGPK.
+
+	  If unsure, say N.
+
 config MOUSE_SERIAL
 	tristate "Serial mouse"
 	select SERIO
diff --git a/drivers/input/mouse/Makefile b/drivers/input/mouse/Makefile
index 9e6e363..799aa3f 100644
--- a/drivers/input/mouse/Makefile
+++ b/drivers/input/mouse/Makefile
@@ -24,3 +24,4 @@ psmouse-$(CONFIG_MOUSE_PS2_LOGIPS2PP)	+= logips2pp.o
 psmouse-$(CONFIG_MOUSE_PS2_LIFEBOOK)	+= lifebook.o
 psmouse-$(CONFIG_MOUSE_PS2_TRACKPOINT)	+= trackpoint.o
 psmouse-$(CONFIG_MOUSE_PS2_TOUCHKIT)	+= touchkit_ps2.o
+psmouse-$(CONFIG_MOUSE_PS2_OLPC)	+= hgpk.o
diff --git a/drivers/input/mouse/hgpk.c b/drivers/input/mouse/hgpk.c
new file mode 100644
index 0000000..605afd2
--- /dev/null
+++ b/drivers/input/mouse/hgpk.c
@@ -0,0 +1,473 @@
+/*
+ * 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->count++;
+	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)
+{
+	if (!(packet[0] & (1<<3)) || (packet[0] & (1<<2)))
+		return -1;
+
+	return 0;
+}
+
+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");
+
+		if (ps2_command(&psmouse->ps2dev, NULL, PSMOUSE_CMD_DISABLE))
+			return -1;
+		psmouse_set_state(psmouse, PSMOUSE_CMD_MODE);
+
+		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;
+
+	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;
+	unsigned long value;
+	int err;
+
+	err = strict_strtoul(buf, 10, &value);
+	if (err || value > 1)
+		return -EINVAL;
+
+	priv = psmouse->private;
+	if (value == priv->powered)
+		return count;
+
+	/* 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;
+}
diff --git a/drivers/input/mouse/hgpk.h b/drivers/input/mouse/hgpk.h
new file mode 100644
index 0000000..a4b2a96
--- /dev/null
+++ b/drivers/input/mouse/hgpk.h
@@ -0,0 +1,49 @@
+/*
+ * OLPC HGPK (XO-1) touchpad PS/2 mouse driver
+ */
+
+#ifndef _HGPK_H
+#define _HGPK_H
+
+enum hgpk_model_t {
+	HGPK_MODEL_PREA = 0x0a,	/* pre-B1s */
+	HGPK_MODEL_A = 0x14,	/* found on B1s, PT disabled in hardware */
+	HGPK_MODEL_B = 0x28,	/* B2s, has capacitance issues */
+	HGPK_MODEL_C = 0x3c,
+	HGPK_MODEL_D = 0x50,	/* C1, mass production */
+};
+
+struct hgpk_data {
+	struct psmouse *psmouse;
+	int powered;
+	int count, x_tally, y_tally;	/* hardware workaround stuff */
+	unsigned long recalib_window;
+	struct delayed_work recalib_wq;
+};
+
+#define hgpk_dbg(psmouse, format, arg...)		\
+	dev_dbg(&(psmouse)->ps2dev.serio->dev, format, ## arg)
+#define hgpk_err(psmouse, format, arg...)		\
+	dev_err(&(psmouse)->ps2dev.serio->dev, format, ## arg)
+#define hgpk_info(psmouse, format, arg...)		\
+	dev_info(&(psmouse)->ps2dev.serio->dev, format, ## arg)
+#define hgpk_warn(psmouse, format, arg...)		\
+	dev_warn(&(psmouse)->ps2dev.serio->dev, format, ## arg)
+#define hgpk_notice(psmouse, format, arg...)		\
+	dev_notice(&(psmouse)->ps2dev.serio->dev, format, ## arg)
+
+#ifdef CONFIG_MOUSE_PS2_OLPC
+int hgpk_detect(struct psmouse *psmouse, int set_properties);
+int hgpk_init(struct psmouse *psmouse);
+#else
+static inline int hgpk_detect(struct psmouse *psmouse, int set_properties)
+{
+	return -ENODEV;
+}
+static inline int hgpk_init(struct psmouse *psmouse)
+{
+	return -ENODEV;
+}
+#endif
+
+#endif
diff --git a/drivers/input/mouse/psmouse-base.c b/drivers/input/mouse/psmouse-base.c
index f7278e6..57640b0 100644
--- a/drivers/input/mouse/psmouse-base.c
+++ b/drivers/input/mouse/psmouse-base.c
@@ -25,6 +25,7 @@
 #include "synaptics.h"
 #include "logips2pp.h"
 #include "alps.h"
+#include "hgpk.h"
 #include "lifebook.h"
 #include "trackpoint.h"
 #include "touchkit_ps2.h"
@@ -636,8 +637,20 @@ static int psmouse_extensions(struct psmouse *psmouse,
 		}
 	}
 
-	if (max_proto > PSMOUSE_IMEX) {
+/*
+ * Try OLPC HGPK touchpad.
+ */
+	if (max_proto > PSMOUSE_IMEX &&
+			hgpk_detect(psmouse, set_properties) == 0) {
+		if (!set_properties || hgpk_init(psmouse) == 0)
+			return PSMOUSE_HGPK;
+/*
+ * Init failed, try basic relative protocols
+ */
+		max_proto = PSMOUSE_IMEX;
+	}
 
+	if (max_proto > PSMOUSE_IMEX) {
 		if (genius_detect(psmouse, set_properties) == 0)
 			return PSMOUSE_GENPS;
 
@@ -768,6 +781,14 @@ static const struct psmouse_protocol psmouse_protocols[] = {
 		.detect		= touchkit_ps2_detect,
 	},
 #endif
+#ifdef CONFIG_MOUSE_PS2_OLPC
+	{
+		.type		= PSMOUSE_HGPK,
+		.name		= "OLPC HGPK",
+		.alias		= "hgpk",
+		.detect		= hgpk_detect,
+	},
+#endif
 	{
 		.type		= PSMOUSE_CORTRON,
 		.name		= "CortronPS/2",
diff --git a/drivers/input/mouse/psmouse.h b/drivers/input/mouse/psmouse.h
index 0f13c1b..8b608a1 100644
--- a/drivers/input/mouse/psmouse.h
+++ b/drivers/input/mouse/psmouse.h
@@ -89,6 +89,7 @@ enum psmouse_type {
 	PSMOUSE_TRACKPOINT,
 	PSMOUSE_TOUCHKIT_PS2,
 	PSMOUSE_CORTRON,
+	PSMOUSE_HGPK,
 	PSMOUSE_AUTO		/* This one should always be last */
 };
 
@@ -99,7 +100,6 @@ int psmouse_reset(struct psmouse *psmouse);
 void psmouse_set_state(struct psmouse *psmouse, enum psmouse_state new_state);
 void psmouse_set_resolution(struct psmouse *psmouse, unsigned int resolution);
 
-
 struct psmouse_attribute {
 	struct device_attribute dattr;
 	void *data;
-- 
1.5.6.5