[PATCH v2] Input: trackpoint - Optimize trackpoint init to use power-on reset

From: Shawn Nematbakhsh
Date: Tue Apr 09 2013 - 17:53:14 EST


From: Shawn Nematbakhsh <shawnn@xxxxxxxxxxxx>

The trackpoint driver sets various parameter default values, all of
which happen to be power-on defaults (Source: IBM TrackPoint Engineering
Specification, Version 4.0. Also confirmed by empirical data).

By sending the power-on reset command to reset all parameters to
power-on state, we can skip the lengthy process of programming all
parameters. In testing, ~2.5 secs of time writing parameters was reduced
to .35 seconds waiting for power-on reset to complete.

Signed-off-by: Shawn Nematbakhsh <shawnn@xxxxxxxxxxxx>
---
Changes since v1:
- Changed handling of 0xfc00 reply to POR.
---
drivers/input/mouse/trackpoint.c | 224 +++++++++++++++++++++++++--------------
drivers/input/mouse/trackpoint.h | 7 +-
2 files changed, 150 insertions(+), 81 deletions(-)

diff --git a/drivers/input/mouse/trackpoint.c b/drivers/input/mouse/trackpoint.c
index f310249..42964d4 100644
--- a/drivers/input/mouse/trackpoint.c
+++ b/drivers/input/mouse/trackpoint.c
@@ -20,6 +20,30 @@
#include "trackpoint.h"

/*
+ * Power-on Reset: Resets all trackpoint parameters, including RAM values,
+ * to defaults.
+ * Returns zero on success, non-zero on failure.
+ */
+static int trackpoint_power_on_reset(struct ps2dev *ps2dev)
+{
+ unsigned char results[2];
+ int tries = 0;
+
+ /* Issue POR command, and repeat up to once if 0xFC00 received */
+ do {
+ if (ps2_command(ps2dev, NULL, MAKE_PS2_CMD(0, 0, TP_COMMAND)) ||
+ ps2_command(ps2dev, results, MAKE_PS2_CMD(0, 2, TP_POR)))
+ return -1;
+ } while (results[0] == 0xFC && results[1] == 0x00 && ++tries < 2);
+
+ /* Check for success response -- 0xAA00 */
+ if (results[0] != 0xAA || results[1] != 0x00)
+ return -1;
+
+ return 0;
+}
+
+/*
* Device IO: read, write and toggle bit
*/
static int trackpoint_read(struct ps2dev *ps2dev, unsigned char loc, unsigned char *results)
@@ -69,6 +93,7 @@ struct trackpoint_attr_data {
unsigned char command;
unsigned char mask;
unsigned char inverted;
+ unsigned char power_on_default;
};

static ssize_t trackpoint_show_int_attr(struct psmouse *psmouse, void *data, char *buf)
@@ -102,10 +127,11 @@ static ssize_t trackpoint_set_int_attr(struct psmouse *psmouse, void *data,
return count;
}

-#define TRACKPOINT_INT_ATTR(_name, _command) \
+#define TRACKPOINT_INT_ATTR(_name, _command, _default) \
static struct trackpoint_attr_data trackpoint_attr_##_name = { \
.field_offset = offsetof(struct trackpoint_data, _name), \
.command = _command, \
+ .power_on_default = _default, \
}; \
PSMOUSE_DEFINE_ATTR(_name, S_IWUSR | S_IRUGO, \
&trackpoint_attr_##_name, \
@@ -139,31 +165,68 @@ static ssize_t trackpoint_set_bit_attr(struct psmouse *psmouse, void *data,
}


-#define TRACKPOINT_BIT_ATTR(_name, _command, _mask, _inv) \
+#define TRACKPOINT_BIT_ATTR(_name, _command, _mask, _inv, _default) \
static struct trackpoint_attr_data trackpoint_attr_##_name = { \
- .field_offset = offsetof(struct trackpoint_data, _name), \
- .command = _command, \
- .mask = _mask, \
- .inverted = _inv, \
+ .field_offset = offsetof(struct trackpoint_data, \
+ _name), \
+ .command = _command, \
+ .mask = _mask, \
+ .inverted = _inv, \
+ .power_on_default = _default, \
}; \
PSMOUSE_DEFINE_ATTR(_name, S_IWUSR | S_IRUGO, \
&trackpoint_attr_##_name, \
trackpoint_show_int_attr, trackpoint_set_bit_attr)

-TRACKPOINT_INT_ATTR(sensitivity, TP_SENS);
-TRACKPOINT_INT_ATTR(speed, TP_SPEED);
-TRACKPOINT_INT_ATTR(inertia, TP_INERTIA);
-TRACKPOINT_INT_ATTR(reach, TP_REACH);
-TRACKPOINT_INT_ATTR(draghys, TP_DRAGHYS);
-TRACKPOINT_INT_ATTR(mindrag, TP_MINDRAG);
-TRACKPOINT_INT_ATTR(thresh, TP_THRESH);
-TRACKPOINT_INT_ATTR(upthresh, TP_UP_THRESH);
-TRACKPOINT_INT_ATTR(ztime, TP_Z_TIME);
-TRACKPOINT_INT_ATTR(jenks, TP_JENKS_CURV);
-
-TRACKPOINT_BIT_ATTR(press_to_select, TP_TOGGLE_PTSON, TP_MASK_PTSON, 0);
-TRACKPOINT_BIT_ATTR(skipback, TP_TOGGLE_SKIPBACK, TP_MASK_SKIPBACK, 0);
-TRACKPOINT_BIT_ATTR(ext_dev, TP_TOGGLE_EXT_DEV, TP_MASK_EXT_DEV, 1);
+#define TRACKPOINT_UPDATE_BIT(_psmouse, _tp, _name) \
+ { \
+ unsigned char _toggle; \
+ struct trackpoint_attr_data *_attr = &trackpoint_attr_##_name; \
+ trackpoint_read(&_psmouse->ps2dev, _attr->command, &_toggle); \
+ if (((_toggle & _attr->mask) == _attr->mask) != \
+ _tp->_name) \
+ trackpoint_toggle_bit(&_psmouse->ps2dev, \
+ _attr->command, \
+ _attr->mask); \
+ }
+
+#define TRACKPOINT_UPDATE(_power_on, _psmouse, _tp, _name) \
+ if (!_power_on || \
+ _tp->_name != trackpoint_attr_##_name.power_on_default) { \
+ if (!trackpoint_attr_##_name.mask) \
+ trackpoint_write(&_psmouse->ps2dev, \
+ trackpoint_attr_##_name.command, \
+ _tp->_name); \
+ else \
+ TRACKPOINT_UPDATE_BIT(_psmouse, _tp, _name); \
+ }
+
+#define TRACKPOINT_SET_POWER_ON_DEFAULT(_tp, _name) \
+ (_tp->_name = trackpoint_attr_##_name.power_on_default)
+
+TRACKPOINT_INT_ATTR(sensitivity, TP_SENS, TP_DEF_SENS);
+TRACKPOINT_INT_ATTR(speed, TP_SPEED, TP_DEF_SPEED);
+TRACKPOINT_INT_ATTR(inertia, TP_INERTIA, TP_DEF_INERTIA);
+TRACKPOINT_INT_ATTR(reach, TP_REACH, TP_DEF_REACH);
+TRACKPOINT_INT_ATTR(draghys, TP_DRAGHYS, TP_DEF_DRAGHYS);
+TRACKPOINT_INT_ATTR(mindrag, TP_MINDRAG, TP_DEF_MINDRAG);
+TRACKPOINT_INT_ATTR(thresh, TP_THRESH, TP_DEF_THRESH);
+TRACKPOINT_INT_ATTR(upthresh, TP_UP_THRESH, TP_DEF_UP_THRESH);
+TRACKPOINT_INT_ATTR(ztime, TP_Z_TIME, TP_DEF_Z_TIME);
+TRACKPOINT_INT_ATTR(jenks, TP_JENKS_CURV, TP_DEF_JENKS_CURV);
+
+TRACKPOINT_BIT_ATTR(press_to_select, TP_TOGGLE_PTSON, TP_MASK_PTSON, 0,
+ TP_DEF_PTSON);
+TRACKPOINT_BIT_ATTR(skipback, TP_TOGGLE_SKIPBACK, TP_MASK_SKIPBACK, 0,
+ TP_DEF_SKIPBACK);
+TRACKPOINT_BIT_ATTR(ext_dev, TP_TOGGLE_EXT_DEV, TP_MASK_EXT_DEV, 1,
+ TP_DEF_EXT_DEV);
+TRACKPOINT_BIT_ATTR(twohand, TP_TOGGLE_TWOHAND, TP_MASK_TWOHAND, 0,
+ TP_DEF_TWOHAND);
+TRACKPOINT_BIT_ATTR(source_tag, TP_TOGGLE_SOURCE_TAG, TP_MASK_SOURCE_TAG, 0,
+ TP_DEF_SOURCE_TAG);
+TRACKPOINT_BIT_ATTR(mb, TP_TOGGLE_MB, TP_MASK_MB, 0,
+ TP_DEF_MB);

static struct attribute *trackpoint_attrs[] = {
&psmouse_attr_sensitivity.dattr.attr,
@@ -179,6 +242,9 @@ static struct attribute *trackpoint_attrs[] = {
&psmouse_attr_press_to_select.dattr.attr,
&psmouse_attr_skipback.dattr.attr,
&psmouse_attr_ext_dev.dattr.attr,
+ &psmouse_attr_twohand.dattr.attr,
+ &psmouse_attr_source_tag.dattr.attr,
+ &psmouse_attr_mb.dattr.attr,
NULL
};

@@ -202,73 +268,63 @@ static int trackpoint_start_protocol(struct psmouse *psmouse, unsigned char *fir
return 0;
}

-static int trackpoint_sync(struct psmouse *psmouse)
+/*
+ * Write parameters to trackpad.
+ * in_power_on_state: Set to true if TP is in default / power-on state (ex. if
+ * power-on reset was run). If so, values will only be
+ * written to TP if they differ from power-on default.
+ */
+static int trackpoint_sync(struct psmouse *psmouse, bool in_power_on_state)
{
struct trackpoint_data *tp = psmouse->private;
- unsigned char toggle;
-
- /* Disable features that may make device unusable with this driver */
- trackpoint_read(&psmouse->ps2dev, TP_TOGGLE_TWOHAND, &toggle);
- if (toggle & TP_MASK_TWOHAND)
- trackpoint_toggle_bit(&psmouse->ps2dev, TP_TOGGLE_TWOHAND, TP_MASK_TWOHAND);

- trackpoint_read(&psmouse->ps2dev, TP_TOGGLE_SOURCE_TAG, &toggle);
- if (toggle & TP_MASK_SOURCE_TAG)
- trackpoint_toggle_bit(&psmouse->ps2dev, TP_TOGGLE_SOURCE_TAG, TP_MASK_SOURCE_TAG);
-
- trackpoint_read(&psmouse->ps2dev, TP_TOGGLE_MB, &toggle);
- if (toggle & TP_MASK_MB)
- trackpoint_toggle_bit(&psmouse->ps2dev, TP_TOGGLE_MB, TP_MASK_MB);
-
- /* Push the config to the device */
- trackpoint_write(&psmouse->ps2dev, TP_SENS, tp->sensitivity);
- trackpoint_write(&psmouse->ps2dev, TP_INERTIA, tp->inertia);
- trackpoint_write(&psmouse->ps2dev, TP_SPEED, tp->speed);
-
- trackpoint_write(&psmouse->ps2dev, TP_REACH, tp->reach);
- trackpoint_write(&psmouse->ps2dev, TP_DRAGHYS, tp->draghys);
- trackpoint_write(&psmouse->ps2dev, TP_MINDRAG, tp->mindrag);
-
- trackpoint_write(&psmouse->ps2dev, TP_THRESH, tp->thresh);
- trackpoint_write(&psmouse->ps2dev, TP_UP_THRESH, tp->upthresh);
-
- trackpoint_write(&psmouse->ps2dev, TP_Z_TIME, tp->ztime);
- trackpoint_write(&psmouse->ps2dev, TP_JENKS_CURV, tp->jenks);
-
- trackpoint_read(&psmouse->ps2dev, TP_TOGGLE_PTSON, &toggle);
- if (((toggle & TP_MASK_PTSON) == TP_MASK_PTSON) != tp->press_to_select)
- trackpoint_toggle_bit(&psmouse->ps2dev, TP_TOGGLE_PTSON, TP_MASK_PTSON);
-
- trackpoint_read(&psmouse->ps2dev, TP_TOGGLE_SKIPBACK, &toggle);
- if (((toggle & TP_MASK_SKIPBACK) == TP_MASK_SKIPBACK) != tp->skipback)
- trackpoint_toggle_bit(&psmouse->ps2dev, TP_TOGGLE_SKIPBACK, TP_MASK_SKIPBACK);
-
- trackpoint_read(&psmouse->ps2dev, TP_TOGGLE_EXT_DEV, &toggle);
- if (((toggle & TP_MASK_EXT_DEV) == TP_MASK_EXT_DEV) != tp->ext_dev)
- trackpoint_toggle_bit(&psmouse->ps2dev, TP_TOGGLE_EXT_DEV, TP_MASK_EXT_DEV);
+ /*
+ * These properties can be changed in this driver. Only
+ * configure them if the values are non-default or if the TP is in
+ * an unknown state.
+ */
+ TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, sensitivity);
+ TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, inertia);
+ TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, speed);
+ TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, reach);
+ TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, draghys);
+ TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, mindrag);
+ TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, thresh);
+ TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, upthresh);
+ TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, ztime);
+ TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, jenks);
+
+ /* toggles */
+ TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, press_to_select);
+ TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, skipback);
+ TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, ext_dev);
+ TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, twohand);
+ TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, source_tag);
+ TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, mb);

return 0;
}

static void trackpoint_defaults(struct trackpoint_data *tp)
{
- tp->press_to_select = TP_DEF_PTSON;
- tp->sensitivity = TP_DEF_SENS;
- tp->speed = TP_DEF_SPEED;
- tp->reach = TP_DEF_REACH;
-
- tp->draghys = TP_DEF_DRAGHYS;
- tp->mindrag = TP_DEF_MINDRAG;
-
- tp->thresh = TP_DEF_THRESH;
- tp->upthresh = TP_DEF_UP_THRESH;
-
- tp->ztime = TP_DEF_Z_TIME;
- tp->jenks = TP_DEF_JENKS_CURV;
-
- tp->inertia = TP_DEF_INERTIA;
- tp->skipback = TP_DEF_SKIPBACK;
- tp->ext_dev = TP_DEF_EXT_DEV;
+ TRACKPOINT_SET_POWER_ON_DEFAULT(tp, sensitivity);
+ TRACKPOINT_SET_POWER_ON_DEFAULT(tp, speed);
+ TRACKPOINT_SET_POWER_ON_DEFAULT(tp, reach);
+ TRACKPOINT_SET_POWER_ON_DEFAULT(tp, draghys);
+ TRACKPOINT_SET_POWER_ON_DEFAULT(tp, mindrag);
+ TRACKPOINT_SET_POWER_ON_DEFAULT(tp, thresh);
+ TRACKPOINT_SET_POWER_ON_DEFAULT(tp, upthresh);
+ TRACKPOINT_SET_POWER_ON_DEFAULT(tp, ztime);
+ TRACKPOINT_SET_POWER_ON_DEFAULT(tp, jenks);
+ TRACKPOINT_SET_POWER_ON_DEFAULT(tp, inertia);
+
+ /* toggles */
+ TRACKPOINT_SET_POWER_ON_DEFAULT(tp, press_to_select);
+ TRACKPOINT_SET_POWER_ON_DEFAULT(tp, skipback);
+ TRACKPOINT_SET_POWER_ON_DEFAULT(tp, ext_dev);
+ TRACKPOINT_SET_POWER_ON_DEFAULT(tp, twohand);
+ TRACKPOINT_SET_POWER_ON_DEFAULT(tp, source_tag);
+ TRACKPOINT_SET_POWER_ON_DEFAULT(tp, mb);
}

static void trackpoint_disconnect(struct psmouse *psmouse)
@@ -281,10 +337,13 @@ static void trackpoint_disconnect(struct psmouse *psmouse)

static int trackpoint_reconnect(struct psmouse *psmouse)
{
+ int reset_fail;
+
if (trackpoint_start_protocol(psmouse, NULL))
return -1;

- if (trackpoint_sync(psmouse))
+ reset_fail = trackpoint_power_on_reset(&psmouse->ps2dev);
+ if (trackpoint_sync(psmouse, !reset_fail))
return -1;

return 0;
@@ -322,7 +381,12 @@ int trackpoint_detect(struct psmouse *psmouse, bool set_properties)
__set_bit(BTN_MIDDLE, psmouse->dev->keybit);

trackpoint_defaults(psmouse->private);
- trackpoint_sync(psmouse);
+
+ error = trackpoint_power_on_reset(&psmouse->ps2dev);
+
+ /* Write defaults to TP only if reset fails. */
+ if (error)
+ trackpoint_sync(psmouse, false);

error = sysfs_create_group(&ps2dev->serio->dev.kobj, &trackpoint_attr_group);
if (error) {
diff --git a/drivers/input/mouse/trackpoint.h b/drivers/input/mouse/trackpoint.h
index e558a70..e0bc03b 100644
--- a/drivers/input/mouse/trackpoint.h
+++ b/drivers/input/mouse/trackpoint.h
@@ -126,6 +126,8 @@
#define TP_DEF_PTSON 0x00
#define TP_DEF_SKIPBACK 0x00
#define TP_DEF_EXT_DEV 0x00 /* 0 means enabled */
+#define TP_DEF_TWOHAND 0x00
+#define TP_DEF_SOURCE_TAG 0x00

#define MAKE_PS2_CMD(params, results, cmd) ((params<<12) | (results<<8) | (cmd))

@@ -136,10 +138,13 @@ struct trackpoint_data
unsigned char thresh, upthresh;
unsigned char ztime, jenks;

+ /* toggles */
unsigned char press_to_select;
unsigned char skipback;
-
unsigned char ext_dev;
+ unsigned char twohand;
+ unsigned char source_tag;
+ unsigned char mb;
};

#ifdef CONFIG_MOUSE_PS2_TRACKPOINT
--
1.7.12.4

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