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

Andres Salomon
2008-09-11T05:32:26Z

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;