1 files changed, 477 insertions, 0 deletions
diff --git a/drivers/input/mouse/hgpk.c b/drivers/input/mouse/hgpk.c
new file mode 100644
index 00000000000..e82d34201e9
--- /dev/null
+++ b/drivers/input/mouse/hgpk.c
@@ -0,0 +1,477 @@
+/*
+ * OLPC HGPK (XO-1) touchpad PS/2 mouse driver
+ *
+ * Copyright (c) 2006-2008 One Laptop Per Child
+ * Authors:
+ *   Zephaniah E. Hull
+ *   Andres Salomon <dilinger@debian.org>
+ *
+ * This driver is partly based on the ALPS driver, which is:
+ *
+ * Copyright (c) 2003 Neil Brown <neilb@cse.unsw.edu.au>
+ * Copyright (c) 2003-2005 Peter Osterlund <petero2@telia.com>
+ * Copyright (c) 2004 Dmitry Torokhov <dtor@mail.ru>
+ * Copyright (c) 2005 Vojtech Pavlik <vojtech@suse.cz>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+/*
+ * The spec from ALPS is available from
+ * <http://wiki.laptop.org/go/Touch_Pad/Tablet>.  It refers to this
+ * device as HGPK (Hybrid GS, PT, and Keymatrix).
+ *
+ * The earliest versions of the device had simultaneous reporting; that
+ * was removed.  After that, the device used the Advanced Mode GS/PT streaming
+ * stuff.  That turned out to be too buggy to support, so we've finally
+ * switched to Mouse Mode (which utilizes only the center 1/3 of the touchpad).
+ */
+
+#define DEBUG
+#include <linux/input.h>
+#include <linux/serio.h>
+#include <linux/libps2.h>
+#include <linux/delay.h>
+#include <asm/olpc.h>
+
+#include "psmouse.h"
+#include "hgpk.h"
+
+static int tpdebug;
+module_param(tpdebug, int, 0644);
+MODULE_PARM_DESC(tpdebug, "enable debugging, dumping packets to KERN_DEBUG.");
+
+static int recalib_delta = 100;
+module_param(recalib_delta, int, 0644);
+MODULE_PARM_DESC(recalib_delta,
+	"packets containing a delta this large will cause a recalibration.");
+
+/*
+ * When the touchpad gets ultra-sensitive, one can keep their finger 1/2"
+ * above the pad and still have it send packets.  This causes a jump cursor
+ * when one places their finger on the pad.  We can probably detect the
+ * jump as we see a large deltas (>= 100px).  In mouse mode, I've been
+ * unable to even come close to 100px deltas during normal usage, so I think
+ * this threshold is safe.  If a large delta occurs, trigger a recalibration.
+ */
+static void hgpk_jumpy_hack(struct psmouse *psmouse, int x, int y)
+{
+	struct hgpk_data *priv = psmouse->private;
+
+	if (abs(x) > recalib_delta || abs(y) > recalib_delta) {
+		hgpk_err(psmouse, ">%dpx jump detected (%d,%d)\n",
+				recalib_delta, x, y);
+		/* My car gets forty rods to the hogshead and that's the
+		 * way I likes it! */
+		psmouse_queue_work(psmouse, &priv->recalib_wq,
+				msecs_to_jiffies(1000));
+	}
+}
+
+/*
+ * We have no idea why this particular hardware bug occurs.  The touchpad
+ * will randomly start spewing packets without anything touching the
+ * pad.  This wouldn't necessarily be bad, but it's indicative of a
+ * severely miscalibrated pad; attempting to use the touchpad while it's
+ * spewing means the cursor will jump all over the place, and act "drunk".
+ *
+ * The packets that are spewed tend to all have deltas between -2 and 2, and
+ * the cursor will move around without really going very far.  It will
+ * tend to end up in the same location; if we tally up the changes over
+ * 100 packets, we end up w/ a final delta of close to 0.  This happens
+ * pretty regularly when the touchpad is spewing, and is pretty hard to
+ * manually trigger (at least for *my* fingers).  So, it makes a perfect
+ * scheme for detecting spews.
+ */
+static void hgpk_spewing_hack(struct psmouse *psmouse,
+			      int l, int r, int x, int y)
+{
+	struct hgpk_data *priv = psmouse->private;
+
+	/* ignore button press packets; many in a row could trigger
+	 * a false-positive! */
+	if (l || r)
+		return;
+
+	priv->x_tally += x;
+	priv->y_tally += y;
+
+	if (++priv->count > 100) {
+		if (abs(priv->x_tally) < 3 && abs(priv->y_tally) < 3) {
+			hgpk_dbg(psmouse, "packet spew detected (%d,%d)\n",
+				 priv->x_tally, priv->y_tally);
+			psmouse_queue_work(psmouse, &priv->recalib_wq,
+					   msecs_to_jiffies(1000));
+		}
+		/* reset every 100 packets */
+		priv->count = 0;
+		priv->x_tally = 0;
+		priv->y_tally = 0;
+	}
+}
+
+/*
+ * HGPK Mouse Mode format (standard mouse format, sans middle button)
+ *
+ * byte 0:	y-over	x-over	y-neg	x-neg	1	0	swr	swl
+ * byte 1:	x7	x6	x5	x4	x3	x2	x1	x0
+ * byte 2:	y7	y6	y5	y4	y3	y2	y1	y0
+ *
+ * swr/swl are the left/right buttons.
+ * x-neg/y-neg are the x and y delta negative bits
+ * x-over/y-over are the x and y overflow bits
+ */
+static int hgpk_validate_byte(unsigned char *packet)
+{
+	return (packet[0] & 0x0C) == 0x08;
+}
+
+static void hgpk_process_packet(struct psmouse *psmouse)
+{
+	struct input_dev *dev = psmouse->dev;
+	unsigned char *packet = psmouse->packet;
+	int x, y, left, right;
+
+	left = packet[0] & 1;
+	right = (packet[0] >> 1) & 1;
+
+	x = packet[1] - ((packet[0] << 4) & 0x100);
+	y = ((packet[0] << 3) & 0x100) - packet[2];
+
+	hgpk_jumpy_hack(psmouse, x, y);
+	hgpk_spewing_hack(psmouse, left, right, x, y);
+
+	if (tpdebug)
+		hgpk_dbg(psmouse, "l=%d r=%d x=%d y=%d\n", left, right, x, y);
+
+	input_report_key(dev, BTN_LEFT, left);
+	input_report_key(dev, BTN_RIGHT, right);
+
+	input_report_rel(dev, REL_X, x);
+	input_report_rel(dev, REL_Y, y);
+
+	input_sync(dev);
+}
+
+static psmouse_ret_t hgpk_process_byte(struct psmouse *psmouse)
+{
+	struct hgpk_data *priv = psmouse->private;
+
+	if (hgpk_validate_byte(psmouse->packet)) {
+		hgpk_dbg(psmouse, "%s: (%d) %02x %02x %02x\n",
+				__func__, psmouse->pktcnt, psmouse->packet[0],
+				psmouse->packet[1], psmouse->packet[2]);
+		return PSMOUSE_BAD_DATA;
+	}
+
+	if (psmouse->pktcnt >= psmouse->pktsize) {
+		hgpk_process_packet(psmouse);
+		return PSMOUSE_FULL_PACKET;
+	}
+
+	if (priv->recalib_window) {
+		if (time_before(jiffies, priv->recalib_window)) {
+			/*
+			 * ugh, got a packet inside our recalibration
+			 * window, schedule another recalibration.
+			 */
+			hgpk_dbg(psmouse,
+				 "packet inside calibration window, "
+				 "queueing another recalibration\n");
+			psmouse_queue_work(psmouse, &priv->recalib_wq,
+					msecs_to_jiffies(1000));
+		}
+		priv->recalib_window = 0;
+	}
+
+	return PSMOUSE_GOOD_DATA;
+}
+
+static int hgpk_force_recalibrate(struct psmouse *psmouse)
+{
+	struct ps2dev *ps2dev = &psmouse->ps2dev;
+	struct hgpk_data *priv = psmouse->private;
+
+	/* C-series touchpads added the recalibrate command */
+	if (psmouse->model < HGPK_MODEL_C)
+		return 0;
+
+	/* we don't want to race with the irq handler, nor with resyncs */
+	psmouse_set_state(psmouse, PSMOUSE_INITIALIZING);
+
+	/* start by resetting the device */
+	psmouse_reset(psmouse);
+
+	/* send the recalibrate request */
+	if (ps2_command(ps2dev, NULL, 0xf5) ||
+	    ps2_command(ps2dev, NULL, 0xf5) ||
+	    ps2_command(ps2dev, NULL, 0xe6) ||
+	    ps2_command(ps2dev, NULL, 0xf5)) {
+		return -1;
+	}
+
+	/* according to ALPS, 150mS is required for recalibration */
+	msleep(150);
+
+	/* XXX: If a finger is down during this delay, recalibration will
+	 * detect capacitance incorrectly.  This is a hardware bug, and
+	 * we don't have a good way to deal with it.  The 2s window stuff
+	 * (below) is our best option for now.
+	 */
+
+	if (ps2_command(ps2dev, NULL, PSMOUSE_CMD_ENABLE))
+		return -1;
+
+	psmouse_set_state(psmouse, PSMOUSE_ACTIVATED);
+
+	/* After we recalibrate, we shouldn't get any packets for 2s.  If
+	 * we do, it's likely that someone's finger was on the touchpad.
+	 * If someone's finger *was* on the touchpad, it's probably
+	 * miscalibrated.  So, we should schedule another recalibration
+	 */
+	priv->recalib_window = jiffies +  msecs_to_jiffies(2000);
+
+	return 0;
+}
+
+/*
+ * This kills power to the touchpad; according to ALPS, current consumption
+ * goes down to 50uA after running this.  To turn power back on, we drive
+ * MS-DAT low.
+ */
+static int hgpk_toggle_power(struct psmouse *psmouse, int enable)
+{
+	struct ps2dev *ps2dev = &psmouse->ps2dev;
+	int timeo;
+
+	/* Added on D-series touchpads */
+	if (psmouse->model < HGPK_MODEL_D)
+		return 0;
+
+	if (enable) {
+		psmouse_set_state(psmouse, PSMOUSE_INITIALIZING);
+
+		/*
+		 * Sending a byte will drive MS-DAT low; this will wake up
+		 * the controller.  Once we get an ACK back from it, it
+		 * means we can continue with the touchpad re-init.  ALPS
+		 * tells us that 1s should be long enough, so set that as
+		 * the upper bound.
+		 */
+		for (timeo = 20; timeo > 0; timeo--) {
+			if (!ps2_sendbyte(&psmouse->ps2dev,
+					PSMOUSE_CMD_DISABLE, 20))
+				break;
+			msleep(50);
+		}
+
+		psmouse_reset(psmouse);
+
+		/* should be all set, enable the touchpad */
+		ps2_command(&psmouse->ps2dev, NULL, PSMOUSE_CMD_ENABLE);
+		psmouse_set_state(psmouse, PSMOUSE_ACTIVATED);
+
+	} else {
+		hgpk_dbg(psmouse, "Powering off touchpad.\n");
+		psmouse_set_state(psmouse, PSMOUSE_IGNORE);
+
+		if (ps2_command(ps2dev, NULL, 0xec) ||
+		    ps2_command(ps2dev, NULL, 0xec) ||
+		    ps2_command(ps2dev, NULL, 0xea)) {
+			return -1;
+		}
+
+		/* probably won't see an ACK, the touchpad will be off */
+		ps2_sendbyte(&psmouse->ps2dev, 0xec, 20);
+	}
+
+	return 0;
+}
+
+static int hgpk_poll(struct psmouse *psmouse)
+{
+	/* We can't poll, so always return failure. */
+	return -1;
+}
+
+static int hgpk_reconnect(struct psmouse *psmouse)
+{
+	/* During suspend/resume the ps2 rails remain powered.  We don't want
+	 * to do a reset because it's flush data out of buffers; however,
+	 * earlier prototypes (B1) had some brokenness that required a reset. */
+	if (olpc_board_at_least(olpc_board(0xb2)))
+		if (psmouse->ps2dev.serio->dev.power.power_state.event !=
+				PM_EVENT_ON)
+			return 0;
+
+	psmouse_reset(psmouse);
+
+	return 0;
+}
+
+static ssize_t hgpk_show_powered(struct psmouse *psmouse, void *data, char *buf)
+{
+	struct hgpk_data *priv = psmouse->private;
+
+	return sprintf(buf, "%d\n", priv->powered);
+}
+
+static ssize_t hgpk_set_powered(struct psmouse *psmouse, void *data,
+				const char *buf, size_t count)
+{
+	struct hgpk_data *priv = psmouse->private;
+	unsigned long value;
+	int err;
+
+	err = strict_strtoul(buf, 10, &value);
+	if (err || value > 1)
+		return -EINVAL;
+
+	if (value != priv->powered) {
+		/*
+		 * hgpk_toggle_power will deal w/ state so
+		 * we're not racing w/ irq
+		 */
+		err = hgpk_toggle_power(psmouse, value);
+		if (!err)
+			priv->powered = value;
+	}
+
+	return err ? err : count;
+}
+
+__PSMOUSE_DEFINE_ATTR(powered, S_IWUSR | S_IRUGO, NULL,
+		      hgpk_show_powered, hgpk_set_powered, 0);
+
+static void hgpk_disconnect(struct psmouse *psmouse)
+{
+	struct hgpk_data *priv = psmouse->private;
+
+	device_remove_file(&psmouse->ps2dev.serio->dev,
+			   &psmouse_attr_powered.dattr);
+	psmouse_reset(psmouse);
+	kfree(priv);
+}
+
+static void hgpk_recalib_work(struct work_struct *work)
+{
+	struct delayed_work *w = container_of(work, struct delayed_work, work);
+	struct hgpk_data *priv = container_of(w, struct hgpk_data, recalib_wq);
+	struct psmouse *psmouse = priv->psmouse;
+
+	hgpk_dbg(psmouse, "recalibrating touchpad..\n");
+
+	if (hgpk_force_recalibrate(psmouse))
+		hgpk_err(psmouse, "recalibration failed!\n");
+}
+
+static int hgpk_register(struct psmouse *psmouse)
+{
+	struct input_dev *dev = psmouse->dev;
+	int err;
+
+	/* unset the things that psmouse-base sets which we don't have */
+	__clear_bit(BTN_MIDDLE, dev->keybit);
+
+	/* set the things we do have */
+	__set_bit(EV_KEY, dev->evbit);
+	__set_bit(EV_REL, dev->evbit);
+
+	__set_bit(REL_X, dev->relbit);
+	__set_bit(REL_Y, dev->relbit);
+
+	__set_bit(BTN_LEFT, dev->keybit);
+	__set_bit(BTN_RIGHT, dev->keybit);
+
+	/* register handlers */
+	psmouse->protocol_handler = hgpk_process_byte;
+	psmouse->poll = hgpk_poll;
+	psmouse->disconnect = hgpk_disconnect;
+	psmouse->reconnect = hgpk_reconnect;
+	psmouse->pktsize = 3;
+
+	/* Disable the idle resync. */
+	psmouse->resync_time = 0;
+	/* Reset after a lot of bad bytes. */
+	psmouse->resetafter = 1024;
+
+	err = device_create_file(&psmouse->ps2dev.serio->dev,
+				 &psmouse_attr_powered.dattr);
+	if (err)
+		hgpk_err(psmouse, "Failed to create sysfs attribute\n");
+
+	return err;
+}
+
+int hgpk_init(struct psmouse *psmouse)
+{
+	struct hgpk_data *priv;
+	int err = -ENOMEM;
+
+	priv = kzalloc(sizeof(struct hgpk_data), GFP_KERNEL);
+	if (!priv)
+		goto alloc_fail;
+
+	psmouse->private = priv;
+	priv->psmouse = psmouse;
+	priv->powered = 1;
+	INIT_DELAYED_WORK(&priv->recalib_wq, hgpk_recalib_work);
+
+	err = psmouse_reset(psmouse);
+	if (err)
+		goto init_fail;
+
+	err = hgpk_register(psmouse);
+	if (err)
+		goto init_fail;
+
+	return 0;
+
+init_fail:
+	kfree(priv);
+alloc_fail:
+	return err;
+}
+
+static enum hgpk_model_t hgpk_get_model(struct psmouse *psmouse)
+{
+	struct ps2dev *ps2dev = &psmouse->ps2dev;
+	unsigned char param[3];
+
+	/* E7, E7, E7, E9 gets us a 3 byte identifier */
+	if (ps2_command(ps2dev,  NULL, PSMOUSE_CMD_SETSCALE21) ||
+	    ps2_command(ps2dev,  NULL, PSMOUSE_CMD_SETSCALE21) ||
+	    ps2_command(ps2dev,  NULL, PSMOUSE_CMD_SETSCALE21) ||
+	    ps2_command(ps2dev, param, PSMOUSE_CMD_GETINFO)) {
+		return -EIO;
+	}
+
+	hgpk_dbg(psmouse, "ID: %02x %02x %02x", param[0], param[1], param[2]);
+
+	/* HGPK signature: 0x67, 0x00, 0x<model> */
+	if (param[0] != 0x67 || param[1] != 0x00)
+		return -ENODEV;
+
+	hgpk_info(psmouse, "OLPC touchpad revision 0x%x\n", param[2]);
+
+	return param[2];
+}
+
+int hgpk_detect(struct psmouse *psmouse, int set_properties)
+{
+	int version;
+
+	version = hgpk_get_model(psmouse);
+	if (version < 0)
+		return version;
+
+	if (set_properties) {
+		psmouse->vendor = "ALPS";
+		psmouse->name = "HGPK";
+		psmouse->model = version;
+	}
+
+	return 0;
+}