1 files changed, 614 insertions, 81 deletions

diff --git a/drivers/input/mouse/hgpk.c b/drivers/input/mouse/hgpk.c
index 1d2205b2480..95577c15ae5 100644
--- a/drivers/input/mouse/hgpk.c
+++ b/drivers/input/mouse/hgpk.c
@@ -40,6 +40,8 @@
 #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.");
@@ -47,48 +49,150 @@ 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.");
+	"packets containing a delta this large will be discarded, and a "
+	"recalibration may be scheduled.");
 
-static int jumpy_delay = 1000;
+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 = 1000;
+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 = 2000;
+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 = 1000;
+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;
+}
+
 /*
- * 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.
+ * 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 void hgpk_jumpy_hack(struct psmouse *psmouse, int x, int y)
+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))) {
+		hgpk_err(psmouse, "detected %dpx jump in x\n", x);
+		priv->xbigj = avx;
+	} else if (approx_half(avx, priv->xbigj)) {
+		hgpk_err(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))) {
+		hgpk_err(psmouse, "detected %dpx jump in y\n", y);
+		priv->ybigj = avy;
+	} else if (approx_half(avy, priv->ybigj)) {
+		hgpk_err(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;
+	}
 
-	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! */
+	priv->xlast = avx;
+	priv->ylast = avy;
+
+	if (do_recal && jumpy_delay) {
+		hgpk_err(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);
 }
 
 /*
@@ -116,20 +220,57 @@ static void hgpk_spewing_hack(struct psmouse *psmouse,
 	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;
 
-	if (++priv->count > 100) {
+	switch (priv->spew_flag) {
+	case NO_SPEW:
+		/* we're not spewing, but this packet might be the start */
+		priv->spew_flag = MAYBE_SPEWING;
+
+		/* fall-through */
+
+	case MAYBE_SPEWING:
+		priv->spew_count++;
+
+		if (priv->spew_count < SPEW_WATCH_COUNT)
+			break;
+
+		/* excessive spew detected, request recalibration */
+		priv->spew_flag = SPEW_DETECTED;
+
+		/* fall-through */
+
+	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) {
-			hgpk_dbg(psmouse, "packet spew detected (%d,%d)\n",
+			hgpk_err(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));
 		}
-		/* reset every 100 packets */
-		priv->count = 0;
-		priv->x_tally = 0;
-		priv->y_tally = 0;
+
+		break;
+	case RECALIBRATING:
+		/* we already detected a spew and requested a recalibration,
+		 * just wait for the queue to kick into action. */
+		break;
 	}
 }
 
@@ -143,25 +284,168 @@ static void hgpk_spewing_hack(struct psmouse *psmouse,
  * 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 int hgpk_validate_byte(unsigned char *packet)
+static bool hgpk_is_byte_valid(struct psmouse *psmouse, unsigned char *packet)
 {
-	return (packet[0] & 0x0C) != 0x08;
+	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)
+		hgpk_dbg(psmouse,
+			 "bad data, mode %d (%d) %02x %02x %02x %02x %02x %02x\n",
+			 priv->mode, pktcnt,
+			 psmouse->packet[0], psmouse->packet[1],
+			 psmouse->packet[2], psmouse->packet[3],
+			 psmouse->packet[4], psmouse->packet[5]);
+
+	return valid;
 }
 
-static void hgpk_process_packet(struct psmouse *psmouse)
+static void hgpk_process_advanced_packet(struct psmouse *psmouse)
 {
-	struct input_dev *dev = psmouse->dev;
+	struct hgpk_data *priv = psmouse->private;
+	struct input_dev *idev = psmouse->dev;
 	unsigned char *packet = psmouse->packet;
-	int x, y, left, right;
+	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)
+			hgpk_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)
+			hgpk_dbg(psmouse, "pd=%d ", down);
+	}
+
+	if (tpdebug)
+		hgpk_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)
+				hgpk_dbg(psmouse, "hard spew detected\n");
+			priv->spew_flag = RECALIBRATING;
+			psmouse_queue_work(psmouse, &priv->recalib_wq,
+					   msecs_to_jiffies(spew_delay));
+		}
+		goto done;
+	}
 
-	left = packet[0] & 1;
-	right = (packet[0] >> 1) & 1;
+	/* 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)
+				hgpk_dbg(psmouse, "discarding\n");
+			goto done;
+		}
+		hgpk_spewing_hack(psmouse, left, right, x_diff, y_diff);
+	}
 
-	x = packet[1] - ((packet[0] << 4) & 0x100);
-	y = ((packet[0] << 3) & 0x100) - packet[2];
+	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)
+		hgpk_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)
+			hgpk_dbg(psmouse, "discarding\n");
+		return;
+	}
 
-	hgpk_jumpy_hack(psmouse, x, y);
 	hgpk_spewing_hack(psmouse, left, right, x, y);
 
 	if (tpdebug)
@@ -180,15 +464,14 @@ 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]);
+	if (!hgpk_is_byte_valid(psmouse, psmouse->packet))
 		return PSMOUSE_BAD_DATA;
-	}
 
 	if (psmouse->pktcnt >= psmouse->pktsize) {
-		hgpk_process_packet(psmouse);
+		if (priv->mode == HGPK_MODE_MOUSE)
+			hgpk_process_simple_packet(psmouse);
+		else
+			hgpk_process_advanced_packet(psmouse);
 		return PSMOUSE_FULL_PACKET;
 	}
 
@@ -210,33 +493,176 @@ static psmouse_ret_t hgpk_process_byte(struct psmouse *psmouse)
 	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) {
+		hgpk_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 ps2dev *ps2dev = &psmouse->ps2dev;
 	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) {
+		hgpk_dbg(psmouse, "recalibrations disabled, ignoring\n");
+		return 0;
+	}
+
+	hgpk_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 */
-	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);
+	err = hgpk_reset_device(psmouse, true);
+	if (err)
+		return err;
 
-	/* XXX: If a finger is down during this delay, recalibration will
+	/*
+	 * 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.
@@ -247,25 +673,35 @@ static int hgpk_force_recalibrate(struct psmouse *psmouse)
 
 	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
+	if (tpdebug)
+		hgpk_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.
 	 */
-	priv->recalib_window = jiffies +  msecs_to_jiffies(recal_guard_time);
+	if (recal_guard_time)
+		priv->recalib_window = jiffies +
+			msecs_to_jiffies(recal_guard_time);
 
 	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.
+ * 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_power(struct psmouse *psmouse, int enable)
+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)
@@ -279,24 +715,27 @@ static int hgpk_toggle_power(struct psmouse *psmouse, int enable)
 		 * 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.
+		 * the upper bound. (in practice, it takes about 3 loops.)
 		 */
 		for (timeo = 20; timeo > 0; timeo--) {
 			if (!ps2_sendbyte(&psmouse->ps2dev,
 					PSMOUSE_CMD_DISABLE, 20))
 				break;
-			msleep(50);
+			msleep(25);
 		}
 
-		psmouse_reset(psmouse);
+		err = hgpk_reset_device(psmouse, false);
+		if (err) {
+			hgpk_err(psmouse, "Failed to reset device!\n");
+			return err;
+		}
 
 		/* should be all set, enable the touchpad */
 		ps2_command(&psmouse->ps2dev, NULL, PSMOUSE_CMD_ENABLE);
 		psmouse_set_state(psmouse, PSMOUSE_ACTIVATED);
-
+		hgpk_dbg(psmouse, "Touchpad powered up.\n");
 	} 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) ||
@@ -304,6 +743,8 @@ static int hgpk_toggle_power(struct psmouse *psmouse, int enable)
 			return -1;
 		}
 
+		psmouse_set_state(psmouse, PSMOUSE_IGNORE);
+
 		/* probably won't see an ACK, the touchpad will be off */
 		ps2_sendbyte(&psmouse->ps2dev, 0xec, 20);
 	}
@@ -319,17 +760,20 @@ static int hgpk_poll(struct psmouse *psmouse)
 
 static int hgpk_reconnect(struct psmouse *psmouse)
 {
-	/* During suspend/resume the ps2 rails remain powered.  We don't want
+	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. */
+	 * 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;
+	priv->powered = 1;
+	return hgpk_reset_device(psmouse, false);
 }
 
 static ssize_t hgpk_show_powered(struct psmouse *psmouse, void *data, char *buf)
@@ -355,7 +799,7 @@ static ssize_t hgpk_set_powered(struct psmouse *psmouse, void *data,
 		 * hgpk_toggle_power will deal w/ state so
 		 * we're not racing w/ irq
 		 */
-		err = hgpk_toggle_power(psmouse, value);
+		err = hgpk_toggle_powersave(psmouse, value);
 		if (!err)
 			priv->powered = value;
 	}
@@ -366,6 +810,65 @@ static ssize_t hgpk_set_powered(struct psmouse *psmouse, void *data,
 __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)
 {
@@ -401,6 +904,8 @@ static void hgpk_disconnect(struct psmouse *psmouse)
 
 	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,
@@ -416,14 +921,13 @@ static void hgpk_recalib_work(struct work_struct *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 hgpk_data *priv = psmouse->private;
 	int err;
 
 	/* register handlers */
@@ -431,13 +935,14 @@ static int hgpk_register(struct psmouse *psmouse)
 	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;
 
+	hgpk_setup_input_device(psmouse->dev, NULL, priv->mode);
+
 	err = device_create_file(&psmouse->ps2dev.serio->dev,
 				 &psmouse_attr_powered.dattr);
 	if (err) {
@@ -445,6 +950,13 @@ static int hgpk_register(struct psmouse *psmouse)
 		return err;
 	}
 
+	err = device_create_file(&psmouse->ps2dev.serio->dev,
+				 &psmouse_attr_hgpk_mode.dattr);
+	if (err) {
+		hgpk_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,
@@ -452,30 +964,40 @@ static int hgpk_register(struct psmouse *psmouse)
 		if (err) {
 			hgpk_err(psmouse,
 				"Failed creating 'recalibrate' sysfs node\n");
-			device_remove_file(&psmouse->ps2dev.serio->dev,
-					&psmouse_attr_powered.dattr);
-			return err;
+			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 = -ENOMEM;
+	int err;
 
 	priv = kzalloc(sizeof(struct hgpk_data), GFP_KERNEL);
-	if (!priv)
+	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 = psmouse_reset(psmouse);
+	err = hgpk_reset_device(psmouse, false);
 	if (err)
 		goto init_fail;
 
@@ -531,3 +1053,14 @@ int hgpk_detect(struct psmouse *psmouse, bool set_properties)
 
 	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));
+	}
+}