Adding upstream version 5.10.209.upstream/5.10.209upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1063 insertions, 0 deletions

diff --git a/drivers/input/mouse/hgpk.c b/drivers/input/mouse/hgpk.c
new file mode 100644
index 000000000..4dc441309
--- /dev/null
+++ b/drivers/input/mouse/hgpk.c
@@ -0,0 +1,1063 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * 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>
+ */
+
+/*
+ * 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/slab.h>
+#include <linux/input.h>
+#include <linux/module.h>
+#include <linux/serio.h>
+#include <linux/libps2.h>
+#include <linux/delay.h>
+#include <asm/olpc.h>
+
+#include "psmouse.h"
+#include "hgpk.h"
+
+#define ILLEGAL_XY 999999
+
+static bool tpdebug;
+module_param(tpdebug, bool, 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 be discarded, and a "
+	"recalibration may be scheduled.");
+
+static int jumpy_delay = 20;
+module_param(jumpy_delay, int, 0644);
+MODULE_PARM_DESC(jumpy_delay,
+	"delay (ms) before recal after jumpiness detected");
+
+static int spew_delay = 1;
+module_param(spew_delay, int, 0644);
+MODULE_PARM_DESC(spew_delay,
+	"delay (ms) before recal after packet spew detected");
+
+static int recal_guard_time;
+module_param(recal_guard_time, int, 0644);
+MODULE_PARM_DESC(recal_guard_time,
+	"interval (ms) during which recal will be restarted if packet received");
+
+static int post_interrupt_delay = 40;
+module_param(post_interrupt_delay, int, 0644);
+MODULE_PARM_DESC(post_interrupt_delay,
+	"delay (ms) before recal after recal interrupt detected");
+
+static bool autorecal = true;
+module_param(autorecal, bool, 0644);
+MODULE_PARM_DESC(autorecal, "enable recalibration in the driver");
+
+static char hgpk_mode_name[16];
+module_param_string(hgpk_mode, hgpk_mode_name, sizeof(hgpk_mode_name), 0644);
+MODULE_PARM_DESC(hgpk_mode,
+	"default hgpk mode: mouse, glidesensor or pentablet");
+
+static int hgpk_default_mode = HGPK_MODE_MOUSE;
+
+static const char * const hgpk_mode_names[] = {
+	[HGPK_MODE_MOUSE] = "Mouse",
+	[HGPK_MODE_GLIDESENSOR] = "GlideSensor",
+	[HGPK_MODE_PENTABLET] = "PenTablet",
+};
+
+static int hgpk_mode_from_name(const char *buf, int len)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(hgpk_mode_names); i++) {
+		const char *name = hgpk_mode_names[i];
+		if (strlen(name) == len && !strncasecmp(name, buf, len))
+			return i;
+	}
+
+	return HGPK_MODE_INVALID;
+}
+
+/*
+ * see if new value is within 20% of half of old value
+ */
+static int approx_half(int curr, int prev)
+{
+	int belowhalf, abovehalf;
+
+	if (curr < 5 || prev < 5)
+		return 0;
+
+	belowhalf = (prev * 8) / 20;
+	abovehalf = (prev * 12) / 20;
+
+	return belowhalf < curr && curr <= abovehalf;
+}
+
+/*
+ * Throw out oddly large delta packets, and any that immediately follow whose
+ * values are each approximately half of the previous.  It seems that the ALPS
+ * firmware emits errant packets, and they get averaged out slowly.
+ */
+static int hgpk_discard_decay_hack(struct psmouse *psmouse, int x, int y)
+{
+	struct hgpk_data *priv = psmouse->private;
+	int avx, avy;
+	bool do_recal = false;
+
+	avx = abs(x);
+	avy = abs(y);
+
+	/* discard if too big, or half that but > 4 times the prev delta */
+	if (avx > recalib_delta ||
+		(avx > recalib_delta / 2 && ((avx / 4) > priv->xlast))) {
+		psmouse_warn(psmouse, "detected %dpx jump in x\n", x);
+		priv->xbigj = avx;
+	} else if (approx_half(avx, priv->xbigj)) {
+		psmouse_warn(psmouse, "detected secondary %dpx jump in x\n", x);
+		priv->xbigj = avx;
+		priv->xsaw_secondary++;
+	} else {
+		if (priv->xbigj && priv->xsaw_secondary > 1)
+			do_recal = true;
+		priv->xbigj = 0;
+		priv->xsaw_secondary = 0;
+	}
+
+	if (avy > recalib_delta ||
+		(avy > recalib_delta / 2 && ((avy / 4) > priv->ylast))) {
+		psmouse_warn(psmouse, "detected %dpx jump in y\n", y);
+		priv->ybigj = avy;
+	} else if (approx_half(avy, priv->ybigj)) {
+		psmouse_warn(psmouse, "detected secondary %dpx jump in y\n", y);
+		priv->ybigj = avy;
+		priv->ysaw_secondary++;
+	} else {
+		if (priv->ybigj && priv->ysaw_secondary > 1)
+			do_recal = true;
+		priv->ybigj = 0;
+		priv->ysaw_secondary = 0;
+	}
+
+	priv->xlast = avx;
+	priv->ylast = avy;
+
+	if (do_recal && jumpy_delay) {
+		psmouse_warn(psmouse, "scheduling recalibration\n");
+		psmouse_queue_work(psmouse, &priv->recalib_wq,
+				msecs_to_jiffies(jumpy_delay));
+	}
+
+	return priv->xbigj || priv->ybigj;
+}
+
+static void hgpk_reset_spew_detection(struct hgpk_data *priv)
+{
+	priv->spew_count = 0;
+	priv->dupe_count = 0;
+	priv->x_tally = 0;
+	priv->y_tally = 0;
+	priv->spew_flag = NO_SPEW;
+}
+
+static void hgpk_reset_hack_state(struct psmouse *psmouse)
+{
+	struct hgpk_data *priv = psmouse->private;
+
+	priv->abs_x = priv->abs_y = -1;
+	priv->xlast = priv->ylast = ILLEGAL_XY;
+	priv->xbigj = priv->ybigj = 0;
+	priv->xsaw_secondary = priv->ysaw_secondary = 0;
+	hgpk_reset_spew_detection(priv);
+}
+
+/*
+ * 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;
+
+	/* don't track spew if the workaround feature has been turned off */
+	if (!spew_delay)
+		return;
+
+	if (abs(x) > 3 || abs(y) > 3) {
+		/* no spew, or spew ended */
+		hgpk_reset_spew_detection(priv);
+		return;
+	}
+
+	/* Keep a tally of the overall delta to the cursor position caused by
+	 * the spew */
+	priv->x_tally += x;
+	priv->y_tally += y;
+
+	switch (priv->spew_flag) {
+	case NO_SPEW:
+		/* we're not spewing, but this packet might be the start */
+		priv->spew_flag = MAYBE_SPEWING;
+
+		fallthrough;
+
+	case MAYBE_SPEWING:
+		priv->spew_count++;
+
+		if (priv->spew_count < SPEW_WATCH_COUNT)
+			break;
+
+		/* excessive spew detected, request recalibration */
+		priv->spew_flag = SPEW_DETECTED;
+
+		fallthrough;
+
+	case SPEW_DETECTED:
+		/* only recalibrate when the overall delta to the cursor
+		 * is really small. if the spew is causing significant cursor
+		 * movement, it is probably a case of the user moving the
+		 * cursor very slowly across the screen. */
+		if (abs(priv->x_tally) < 3 && abs(priv->y_tally) < 3) {
+			psmouse_warn(psmouse, "packet spew detected (%d,%d)\n",
+				     priv->x_tally, priv->y_tally);
+			priv->spew_flag = RECALIBRATING;
+			psmouse_queue_work(psmouse, &priv->recalib_wq,
+					   msecs_to_jiffies(spew_delay));
+		}
+
+		break;
+	case RECALIBRATING:
+		/* we already detected a spew and requested a recalibration,
+		 * just wait for the queue to kick into action. */
+		break;
+	}
+}
+
+/*
+ * 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
+ *
+ * ---
+ *
+ * HGPK Advanced Mode - single-mode format
+ *
+ * byte 0(PT):  1    1    0    0    1    1     1     1
+ * byte 0(GS):  1    1    1    1    1    1     1     1
+ * byte 1:      0   x6   x5   x4   x3   x2    x1    x0
+ * byte 2(PT):  0    0   x9   x8   x7    ? pt-dsw    0
+ * byte 2(GS):  0  x10   x9   x8   x7    ? gs-dsw pt-dsw
+ * byte 3:      0   y9   y8   y7    1    0   swr   swl
+ * byte 4:      0   y6   y5   y4   y3   y2    y1    y0
+ * byte 5:      0   z6   z5   z4   z3   z2    z1    z0
+ *
+ * ?'s are not defined in the protocol spec, may vary between models.
+ *
+ * swr/swl are the left/right buttons.
+ *
+ * pt-dsw/gs-dsw indicate that the pt/gs sensor is detecting a
+ * pen/finger
+ */
+static bool hgpk_is_byte_valid(struct psmouse *psmouse, unsigned char *packet)
+{
+	struct hgpk_data *priv = psmouse->private;
+	int pktcnt = psmouse->pktcnt;
+	bool valid;
+
+	switch (priv->mode) {
+	case HGPK_MODE_MOUSE:
+		valid = (packet[0] & 0x0C) == 0x08;
+		break;
+
+	case HGPK_MODE_GLIDESENSOR:
+		valid = pktcnt == 1 ?
+			packet[0] == HGPK_GS : !(packet[pktcnt - 1] & 0x80);
+		break;
+
+	case HGPK_MODE_PENTABLET:
+		valid = pktcnt == 1 ?
+			packet[0] == HGPK_PT : !(packet[pktcnt - 1] & 0x80);
+		break;
+
+	default:
+		valid = false;
+		break;
+	}
+
+	if (!valid)
+		psmouse_dbg(psmouse,
+			    "bad data, mode %d (%d) %*ph\n",
+			    priv->mode, pktcnt, 6, psmouse->packet);
+
+	return valid;
+}
+
+static void hgpk_process_advanced_packet(struct psmouse *psmouse)
+{
+	struct hgpk_data *priv = psmouse->private;
+	struct input_dev *idev = psmouse->dev;
+	unsigned char *packet = psmouse->packet;
+	int down = !!(packet[2] & 2);
+	int left = !!(packet[3] & 1);
+	int right = !!(packet[3] & 2);
+	int x = packet[1] | ((packet[2] & 0x78) << 4);
+	int y = packet[4] | ((packet[3] & 0x70) << 3);
+
+	if (priv->mode == HGPK_MODE_GLIDESENSOR) {
+		int pt_down = !!(packet[2] & 1);
+		int finger_down = !!(packet[2] & 2);
+		int z = packet[5];
+
+		input_report_abs(idev, ABS_PRESSURE, z);
+		if (tpdebug)
+			psmouse_dbg(psmouse, "pd=%d fd=%d z=%d",
+				    pt_down, finger_down, z);
+	} else {
+		/*
+		 * PenTablet mode does not report pressure, so we don't
+		 * report it here
+		 */
+		if (tpdebug)
+			psmouse_dbg(psmouse, "pd=%d ", down);
+	}
+
+	if (tpdebug)
+		psmouse_dbg(psmouse, "l=%d r=%d x=%d y=%d\n",
+			    left, right, x, y);
+
+	input_report_key(idev, BTN_TOUCH, down);
+	input_report_key(idev, BTN_LEFT, left);
+	input_report_key(idev, BTN_RIGHT, right);
+
+	/*
+	 * If this packet says that the finger was removed, reset our position
+	 * tracking so that we don't erroneously detect a jump on next press.
+	 */
+	if (!down) {
+		hgpk_reset_hack_state(psmouse);
+		goto done;
+	}
+
+	/*
+	 * Weed out duplicate packets (we get quite a few, and they mess up
+	 * our jump detection)
+	 */
+	if (x == priv->abs_x && y == priv->abs_y) {
+		if (++priv->dupe_count > SPEW_WATCH_COUNT) {
+			if (tpdebug)
+				psmouse_dbg(psmouse, "hard spew detected\n");
+			priv->spew_flag = RECALIBRATING;
+			psmouse_queue_work(psmouse, &priv->recalib_wq,
+					   msecs_to_jiffies(spew_delay));
+		}
+		goto done;
+	}
+
+	/* not a duplicate, continue with position reporting */
+	priv->dupe_count = 0;
+
+	/* Don't apply hacks in PT mode, it seems reliable */
+	if (priv->mode != HGPK_MODE_PENTABLET && priv->abs_x != -1) {
+		int x_diff = priv->abs_x - x;
+		int y_diff = priv->abs_y - y;
+		if (hgpk_discard_decay_hack(psmouse, x_diff, y_diff)) {
+			if (tpdebug)
+				psmouse_dbg(psmouse, "discarding\n");
+			goto done;
+		}
+		hgpk_spewing_hack(psmouse, left, right, x_diff, y_diff);
+	}
+
+	input_report_abs(idev, ABS_X, x);
+	input_report_abs(idev, ABS_Y, y);
+	priv->abs_x = x;
+	priv->abs_y = y;
+
+done:
+	input_sync(idev);
+}
+
+static void hgpk_process_simple_packet(struct psmouse *psmouse)
+{
+	struct input_dev *dev = psmouse->dev;
+	unsigned char *packet = psmouse->packet;
+	int left = packet[0] & 1;
+	int right = (packet[0] >> 1) & 1;
+	int x = packet[1] - ((packet[0] << 4) & 0x100);
+	int y = ((packet[0] << 3) & 0x100) - packet[2];
+
+	if (packet[0] & 0xc0)
+		psmouse_dbg(psmouse,
+			    "overflow -- 0x%02x 0x%02x 0x%02x\n",
+			    packet[0], packet[1], packet[2]);
+
+	if (hgpk_discard_decay_hack(psmouse, x, y)) {
+		if (tpdebug)
+			psmouse_dbg(psmouse, "discarding\n");
+		return;
+	}
+
+	hgpk_spewing_hack(psmouse, left, right, x, y);
+
+	if (tpdebug)
+		psmouse_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_is_byte_valid(psmouse, psmouse->packet))
+		return PSMOUSE_BAD_DATA;
+
+	if (psmouse->pktcnt >= psmouse->pktsize) {
+		if (priv->mode == HGPK_MODE_MOUSE)
+			hgpk_process_simple_packet(psmouse);
+		else
+			hgpk_process_advanced_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.
+			 */
+			psmouse_dbg(psmouse,
+				    "packet inside calibration window, queueing another recalibration\n");
+			psmouse_queue_work(psmouse, &priv->recalib_wq,
+					msecs_to_jiffies(post_interrupt_delay));
+		}
+		priv->recalib_window = 0;
+	}
+
+	return PSMOUSE_GOOD_DATA;
+}
+
+static int hgpk_select_mode(struct psmouse *psmouse)
+{
+	struct ps2dev *ps2dev = &psmouse->ps2dev;
+	struct hgpk_data *priv = psmouse->private;
+	int i;
+	int cmd;
+
+	/*
+	 * 4 disables to enable advanced mode
+	 * then 3 0xf2 bytes as the preamble for GS/PT selection
+	 */
+	const int advanced_init[] = {
+		PSMOUSE_CMD_DISABLE, PSMOUSE_CMD_DISABLE,
+		PSMOUSE_CMD_DISABLE, PSMOUSE_CMD_DISABLE,
+		0xf2, 0xf2, 0xf2,
+	};
+
+	switch (priv->mode) {
+	case HGPK_MODE_MOUSE:
+		psmouse->pktsize = 3;
+		break;
+
+	case HGPK_MODE_GLIDESENSOR:
+	case HGPK_MODE_PENTABLET:
+		psmouse->pktsize = 6;
+
+		/* Switch to 'Advanced mode.', four disables in a row. */
+		for (i = 0; i < ARRAY_SIZE(advanced_init); i++)
+			if (ps2_command(ps2dev, NULL, advanced_init[i]))
+				return -EIO;
+
+		/* select between GlideSensor (mouse) or PenTablet */
+		cmd = priv->mode == HGPK_MODE_GLIDESENSOR ?
+			PSMOUSE_CMD_SETSCALE11 : PSMOUSE_CMD_SETSCALE21;
+
+		if (ps2_command(ps2dev, NULL, cmd))
+			return -EIO;
+		break;
+
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static void hgpk_setup_input_device(struct input_dev *input,
+				    struct input_dev *old_input,
+				    enum hgpk_mode mode)
+{
+	if (old_input) {
+		input->name = old_input->name;
+		input->phys = old_input->phys;
+		input->id = old_input->id;
+		input->dev.parent = old_input->dev.parent;
+	}
+
+	memset(input->evbit, 0, sizeof(input->evbit));
+	memset(input->relbit, 0, sizeof(input->relbit));
+	memset(input->keybit, 0, sizeof(input->keybit));
+
+	/* All modes report left and right buttons */
+	__set_bit(EV_KEY, input->evbit);
+	__set_bit(BTN_LEFT, input->keybit);
+	__set_bit(BTN_RIGHT, input->keybit);
+
+	switch (mode) {
+	case HGPK_MODE_MOUSE:
+		__set_bit(EV_REL, input->evbit);
+		__set_bit(REL_X, input->relbit);
+		__set_bit(REL_Y, input->relbit);
+		break;
+
+	case HGPK_MODE_GLIDESENSOR:
+		__set_bit(BTN_TOUCH, input->keybit);
+		__set_bit(BTN_TOOL_FINGER, input->keybit);
+
+		__set_bit(EV_ABS, input->evbit);
+
+		/* GlideSensor has pressure sensor, PenTablet does not */
+		input_set_abs_params(input, ABS_PRESSURE, 0, 15, 0, 0);
+
+		/* From device specs */
+		input_set_abs_params(input, ABS_X, 0, 399, 0, 0);
+		input_set_abs_params(input, ABS_Y, 0, 290, 0, 0);
+
+		/* Calculated by hand based on usable size (52mm x 38mm) */
+		input_abs_set_res(input, ABS_X, 8);
+		input_abs_set_res(input, ABS_Y, 8);
+		break;
+
+	case HGPK_MODE_PENTABLET:
+		__set_bit(BTN_TOUCH, input->keybit);
+		__set_bit(BTN_TOOL_FINGER, input->keybit);
+
+		__set_bit(EV_ABS, input->evbit);
+
+		/* From device specs */
+		input_set_abs_params(input, ABS_X, 0, 999, 0, 0);
+		input_set_abs_params(input, ABS_Y, 5, 239, 0, 0);
+
+		/* Calculated by hand based on usable size (156mm x 38mm) */
+		input_abs_set_res(input, ABS_X, 6);
+		input_abs_set_res(input, ABS_Y, 8);
+		break;
+
+	default:
+		BUG();
+	}
+}
+
+static int hgpk_reset_device(struct psmouse *psmouse, bool recalibrate)
+{
+	int err;
+
+	psmouse_reset(psmouse);
+
+	if (recalibrate) {
+		struct ps2dev *ps2dev = &psmouse->ps2dev;
+
+		/* 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);
+	}
+
+	err = hgpk_select_mode(psmouse);
+	if (err) {
+		psmouse_err(psmouse, "failed to select mode\n");
+		return err;
+	}
+
+	hgpk_reset_hack_state(psmouse);
+
+	return 0;
+}
+
+static int hgpk_force_recalibrate(struct psmouse *psmouse)
+{
+	struct hgpk_data *priv = psmouse->private;
+	int err;
+
+	/* C-series touchpads added the recalibrate command */
+	if (psmouse->model < HGPK_MODEL_C)
+		return 0;
+
+	if (!autorecal) {
+		psmouse_dbg(psmouse, "recalibration disabled, ignoring\n");
+		return 0;
+	}
+
+	psmouse_dbg(psmouse, "recalibrating touchpad..\n");
+
+	/* we don't want to race with the irq handler, nor with resyncs */
+	psmouse_set_state(psmouse, PSMOUSE_INITIALIZING);
+
+	/* start by resetting the device */
+	err = hgpk_reset_device(psmouse, true);
+	if (err)
+		return err;
+
+	/*
+	 * 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 (psmouse_activate(psmouse))
+		return -1;
+
+	if (tpdebug)
+		psmouse_dbg(psmouse, "touchpad reactivated\n");
+
+	/*
+	 * If we get packets right away after recalibrating, it's likely
+	 * that a finger was on the touchpad.  If so, it's probably
+	 * miscalibrated, so we optionally schedule another.
+	 */
+	if (recal_guard_time)
+		priv->recalib_window = jiffies +
+			msecs_to_jiffies(recal_guard_time);
+
+	return 0;
+}
+
+/*
+ * This puts the touchpad in a power saving mode; according to ALPS, current
+ * consumption goes down to 50uA after running this.  To turn power back on,
+ * we drive MS-DAT low.  Measuring with a 1mA resolution ammeter says that
+ * the current on the SUS_3.3V rail drops from 3mA or 4mA to 0 when we do this.
+ *
+ * We have no formal spec that details this operation -- the low-power
+ * sequence came from a long-lost email trail.
+ */
+static int hgpk_toggle_powersave(struct psmouse *psmouse, int enable)
+{
+	struct ps2dev *ps2dev = &psmouse->ps2dev;
+	int timeo;
+	int err;
+
+	/* 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. (in practice, it takes about 3 loops.)
+		 */
+		for (timeo = 20; timeo > 0; timeo--) {
+			if (!ps2_sendbyte(ps2dev, PSMOUSE_CMD_DISABLE, 20))
+				break;
+			msleep(25);
+		}
+
+		err = hgpk_reset_device(psmouse, false);
+		if (err) {
+			psmouse_err(psmouse, "Failed to reset device!\n");
+			return err;
+		}
+
+		/* should be all set, enable the touchpad */
+		psmouse_activate(psmouse);
+		psmouse_dbg(psmouse, "Touchpad powered up.\n");
+	} else {
+		psmouse_dbg(psmouse, "Powering off touchpad.\n");
+
+		if (ps2_command(ps2dev, NULL, 0xec) ||
+		    ps2_command(ps2dev, NULL, 0xec) ||
+		    ps2_command(ps2dev, NULL, 0xea)) {
+			return -1;
+		}
+
+		psmouse_set_state(psmouse, PSMOUSE_IGNORE);
+
+		/* probably won't see an ACK, the touchpad will be off */
+		ps2_sendbyte(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)
+{
+	struct hgpk_data *priv = psmouse->private;
+
+	/*
+	 * 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;
+
+	priv->powered = 1;
+	return hgpk_reset_device(psmouse, false);
+}
+
+static ssize_t hgpk_show_powered(struct psmouse *psmouse, void *data, char *buf)
+{
+	struct hgpk_data *priv = psmouse->private;
+
+	return sprintf(buf, "%d\n", priv->powered);
+}
+
+static ssize_t hgpk_set_powered(struct psmouse *psmouse, void *data,
+				const char *buf, size_t count)
+{
+	struct hgpk_data *priv = psmouse->private;
+	unsigned int value;
+	int err;
+
+	err = kstrtouint(buf, 10, &value);
+	if (err)
+		return err;
+
+	if (value > 1)
+		return -EINVAL;
+
+	if (value != priv->powered) {
+		/*
+		 * hgpk_toggle_power will deal w/ state so
+		 * we're not racing w/ irq
+		 */
+		err = hgpk_toggle_powersave(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, false);
+
+static ssize_t attr_show_mode(struct psmouse *psmouse, void *data, char *buf)
+{
+	struct hgpk_data *priv = psmouse->private;
+
+	return sprintf(buf, "%s\n", hgpk_mode_names[priv->mode]);
+}
+
+static ssize_t attr_set_mode(struct psmouse *psmouse, void *data,
+			     const char *buf, size_t len)
+{
+	struct hgpk_data *priv = psmouse->private;
+	enum hgpk_mode old_mode = priv->mode;
+	enum hgpk_mode new_mode = hgpk_mode_from_name(buf, len);
+	struct input_dev *old_dev = psmouse->dev;
+	struct input_dev *new_dev;
+	int err;
+
+	if (new_mode == HGPK_MODE_INVALID)
+		return -EINVAL;
+
+	if (old_mode == new_mode)
+		return len;
+
+	new_dev = input_allocate_device();
+	if (!new_dev)
+		return -ENOMEM;
+
+	psmouse_set_state(psmouse, PSMOUSE_INITIALIZING);
+
+	/* Switch device into the new mode */
+	priv->mode = new_mode;
+	err = hgpk_reset_device(psmouse, false);
+	if (err)
+		goto err_try_restore;
+
+	hgpk_setup_input_device(new_dev, old_dev, new_mode);
+
+	psmouse_set_state(psmouse, PSMOUSE_CMD_MODE);
+
+	err = input_register_device(new_dev);
+	if (err)
+		goto err_try_restore;
+
+	psmouse->dev = new_dev;
+	input_unregister_device(old_dev);
+
+	return len;
+
+err_try_restore:
+	input_free_device(new_dev);
+	priv->mode = old_mode;
+	hgpk_reset_device(psmouse, false);
+
+	return err;
+}
+
+PSMOUSE_DEFINE_ATTR(hgpk_mode, S_IWUSR | S_IRUGO, NULL,
+		    attr_show_mode, attr_set_mode);
+
+static ssize_t hgpk_trigger_recal_show(struct psmouse *psmouse,
+		void *data, char *buf)
+{
+	return -EINVAL;
+}
+
+static ssize_t hgpk_trigger_recal(struct psmouse *psmouse, void *data,
+				const char *buf, size_t count)
+{
+	struct hgpk_data *priv = psmouse->private;
+	unsigned int value;
+	int err;
+
+	err = kstrtouint(buf, 10, &value);
+	if (err)
+		return err;
+
+	if (value != 1)
+		return -EINVAL;
+
+	/*
+	 * We queue work instead of doing recalibration right here
+	 * to avoid adding locking to to hgpk_force_recalibrate()
+	 * since workqueue provides serialization.
+	 */
+	psmouse_queue_work(psmouse, &priv->recalib_wq, 0);
+	return count;
+}
+
+__PSMOUSE_DEFINE_ATTR(recalibrate, S_IWUSR | S_IRUGO, NULL,
+		      hgpk_trigger_recal_show, hgpk_trigger_recal, false);
+
+static void hgpk_disconnect(struct psmouse *psmouse)
+{
+	struct hgpk_data *priv = psmouse->private;
+
+	device_remove_file(&psmouse->ps2dev.serio->dev,
+			   &psmouse_attr_powered.dattr);
+	device_remove_file(&psmouse->ps2dev.serio->dev,
+			   &psmouse_attr_hgpk_mode.dattr);
+
+	if (psmouse->model >= HGPK_MODEL_C)
+		device_remove_file(&psmouse->ps2dev.serio->dev,
+				   &psmouse_attr_recalibrate.dattr);
+
+	psmouse_reset(psmouse);
+	kfree(priv);
+}
+
+static void hgpk_recalib_work(struct work_struct *work)
+{
+	struct delayed_work *w = to_delayed_work(work);
+	struct hgpk_data *priv = container_of(w, struct hgpk_data, recalib_wq);
+	struct psmouse *psmouse = priv->psmouse;
+
+	if (hgpk_force_recalibrate(psmouse))
+		psmouse_err(psmouse, "recalibration failed!\n");
+}
+
+static int hgpk_register(struct psmouse *psmouse)
+{
+	struct hgpk_data *priv = psmouse->private;
+	int err;
+
+	/* register handlers */
+	psmouse->protocol_handler = hgpk_process_byte;
+	psmouse->poll = hgpk_poll;
+	psmouse->disconnect = hgpk_disconnect;
+	psmouse->reconnect = hgpk_reconnect;
+
+	/* Disable the idle resync. */
+	psmouse->resync_time = 0;
+	/* Reset after a lot of bad bytes. */
+	psmouse->resetafter = 1024;
+
+	hgpk_setup_input_device(psmouse->dev, NULL, priv->mode);
+
+	err = device_create_file(&psmouse->ps2dev.serio->dev,
+				 &psmouse_attr_powered.dattr);
+	if (err) {
+		psmouse_err(psmouse, "Failed creating 'powered' sysfs node\n");
+		return err;
+	}
+
+	err = device_create_file(&psmouse->ps2dev.serio->dev,
+				 &psmouse_attr_hgpk_mode.dattr);
+	if (err) {
+		psmouse_err(psmouse,
+			    "Failed creating 'hgpk_mode' sysfs node\n");
+		goto err_remove_powered;
+	}
+
+	/* C-series touchpads added the recalibrate command */
+	if (psmouse->model >= HGPK_MODEL_C) {
+		err = device_create_file(&psmouse->ps2dev.serio->dev,
+					 &psmouse_attr_recalibrate.dattr);
+		if (err) {
+			psmouse_err(psmouse,
+				    "Failed creating 'recalibrate' sysfs node\n");
+			goto err_remove_mode;
+		}
+	}
+
+	return 0;
+
+err_remove_mode:
+	device_remove_file(&psmouse->ps2dev.serio->dev,
+			   &psmouse_attr_hgpk_mode.dattr);
+err_remove_powered:
+	device_remove_file(&psmouse->ps2dev.serio->dev,
+			   &psmouse_attr_powered.dattr);
+	return err;
+}
+
+int hgpk_init(struct psmouse *psmouse)
+{
+	struct hgpk_data *priv;
+	int err;
+
+	priv = kzalloc(sizeof(struct hgpk_data), GFP_KERNEL);
+	if (!priv) {
+		err = -ENOMEM;
+		goto alloc_fail;
+	}
+
+	psmouse->private = priv;
+
+	priv->psmouse = psmouse;
+	priv->powered = true;
+	priv->mode = hgpk_default_mode;
+	INIT_DELAYED_WORK(&priv->recalib_wq, hgpk_recalib_work);
+
+	err = hgpk_reset_device(psmouse, false);
+	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;
+	}
+
+	psmouse_dbg(psmouse, "ID: %*ph\n", 3, param);
+
+	/* HGPK signature: 0x67, 0x00, 0x<model> */
+	if (param[0] != 0x67 || param[1] != 0x00)
+		return -ENODEV;
+
+	psmouse_info(psmouse, "OLPC touchpad revision 0x%x\n", param[2]);
+
+	return param[2];
+}
+
+int hgpk_detect(struct psmouse *psmouse, bool 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;
+}
+
+void hgpk_module_init(void)
+{
+	hgpk_default_mode = hgpk_mode_from_name(hgpk_mode_name,
+						strlen(hgpk_mode_name));
+	if (hgpk_default_mode == HGPK_MODE_INVALID) {
+		hgpk_default_mode = HGPK_MODE_MOUSE;
+		strlcpy(hgpk_mode_name, hgpk_mode_names[HGPK_MODE_MOUSE],
+			sizeof(hgpk_mode_name));
+	}
+}