[PATCH] input: psmouse: create an 'enabled' sysfs attribute to squelch mouse

[Andres Salomon <dilinger@queued.net>]

From: Paul Fox <pgf@laptop.org>

on OLPC XO laptops, at least one model of touchpad (sentelic)
emits continuous jittery motion reports when the laptop is
configured in "ebook" mode.  the touchpad is inaccessible in
that configuration, so we simply disable it.

these motion reports will wake the SoC when put to sleep, so simply
ignoring the events is not a possibilty; the device must be disabled.

[dilinger@queued.net: drop psmouse_resync changes, add attribute comment,
 and add psmouse_cleanup workaround]

Signed-off-by: Andres Salomon <dilinger@queued.net>
---
 drivers/input/mouse/psmouse-base.c |   20 ++++++++++++++++++--
 drivers/input/mouse/psmouse.h      |    1 +
 2 files changed, 19 insertions(+), 2 deletions(-)

diff --git a/drivers/input/mouse/psmouse-base.c b/drivers/input/mouse/psmouse-base.c
index 22fe254..a115534 100644
--- a/drivers/input/mouse/psmouse-base.c
+++ b/drivers/input/mouse/psmouse-base.c
@@ -87,6 +87,13 @@ PSMOUSE_DEFINE_ATTR(resetafter, S_IWUSR | S_IRUGO,
 PSMOUSE_DEFINE_ATTR(resync_time, S_IWUSR | S_IRUGO,
 			(void *) offsetof(struct psmouse, resync_time),
 			psmouse_show_int_attr, psmouse_set_int_attr);
+/*
+ * There's no need for a custom handler for the 'enabled' attr;
+ * psmouse_attr_set_helper will take care of disabling and enabling for us.
+ */
+PSMOUSE_DEFINE_ATTR(enabled, S_IWUSR | S_IRUGO,
+			(void *) offsetof(struct psmouse, enabled),
+			psmouse_show_int_attr, psmouse_set_int_attr);
 
 static struct attribute *psmouse_attributes[] = {
 	&psmouse_attr_protocol.dattr.attr,
@@ -94,6 +101,7 @@ static struct attribute *psmouse_attributes[] = {
 	&psmouse_attr_resolution.dattr.attr,
 	&psmouse_attr_resetafter.dattr.attr,
 	&psmouse_attr_resync_time.dattr.attr,
+	&psmouse_attr_enabled.dattr.attr,
 	NULL
 };
 
@@ -1094,6 +1102,9 @@ static void psmouse_initialize(struct psmouse *psmouse)
 
 int psmouse_activate(struct psmouse *psmouse)
 {
+	if (!psmouse->enabled)
+		return 0;
+
 	if (ps2_command(&psmouse->ps2dev, NULL, PSMOUSE_CMD_ENABLE)) {
 		psmouse_warn(psmouse, "Failed to enable mouse on %s\n",
 			     psmouse->ps2dev.serio->phys);
@@ -1256,7 +1267,8 @@ static void psmouse_cleanup(struct serio *serio)
  * Some boxes, such as HP nx7400, get terribly confused if mouse
  * is not fully enabled before suspending/shutting down.
  */
-	ps2_command(&psmouse->ps2dev, NULL, PSMOUSE_CMD_ENABLE);
+	if (psmouse->enabled)
+		ps2_command(&psmouse->ps2dev, NULL, PSMOUSE_CMD_ENABLE);
 
 	if (parent) {
 		if (parent->pt_deactivate)
@@ -1418,6 +1430,7 @@ static int psmouse_connect(struct serio *serio, struct serio_driver *drv)
 	psmouse->resolution = psmouse_resolution;
 	psmouse->resetafter = psmouse_resetafter;
 	psmouse->resync_time = parent ? 0 : psmouse_resync_time;
+	psmouse->enabled = true;
 	psmouse->smartscroll = psmouse_smartscroll;
 
 	psmouse_switch_protocol(psmouse, NULL);
@@ -1516,7 +1529,10 @@ static int psmouse_reconnect(struct serio *serio)
 	if (parent && parent->pt_activate)
 		parent->pt_activate(parent);
 
-	psmouse_activate(psmouse);
+	if (psmouse->enabled)
+		psmouse_activate(psmouse);
+	else
+		psmouse_deactivate(psmouse);
 	rc = 0;
 
 out:
diff --git a/drivers/input/mouse/psmouse.h b/drivers/input/mouse/psmouse.h
index fe1df23..aa30321 100644
--- a/drivers/input/mouse/psmouse.h
+++ b/drivers/input/mouse/psmouse.h
@@ -62,6 +62,7 @@ struct psmouse {
 	unsigned int resolution;
 	unsigned int resetafter;
 	unsigned int resync_time;
+	bool enabled;
 	bool smartscroll;	/* Logitech only */
 
 	psmouse_ret_t (*protocol_handler)(struct psmouse *psmouse);
-- 
1.7.2.5