Add interface to enable/disable all wakeup events from sysfs

As per OLPC trac #7981, we need a fastpath method to enable/disable
all events via a single EC command to decrease resume latency time.
This patch adds an "all" file to /sys/power/wakeup_events that
provides this capability. Writing 1 to this file will enable
all SCI events, writing 0 will disable them all.

Signed-off-by: Deepak Saxena <dsaxena@laptop.org>

1 files changed, 42 insertions, 0 deletions

diff --git a/arch/x86/kernel/olpc-pm.c b/arch/x86/kernel/olpc-pm.c
index acedefbba498..9532a5b16b60 100644
--- a/arch/x86/kernel/olpc-pm.c
+++ b/arch/x86/kernel/olpc-pm.c
@@ -711,6 +711,9 @@ static struct attribute_group olpc_attrs = {
 static ssize_t wackup_event_show(struct kobject *s, struct kobj_attribute *attr, char *buf);
 static ssize_t wackup_event_store(struct kobject *s, struct kobj_attribute *attr, const char *buf, size_t n);
 
+static ssize_t wackup_all_show(struct kobject *s, struct kobj_attribute *attr, char *buf);
+static ssize_t wackup_all_store(struct kobject *s, struct kobj_attribute *attr, const char *buf, size_t n);
+
 static struct kobj_attribute wackup_event_attr[] = {
 	__ATTR(ps2event, 0600, wackup_event_show, wackup_event_store),
 	__ATTR(battery_state, 0600, wackup_event_show, wackup_event_store),
@@ -719,6 +722,7 @@ static struct kobj_attribute wackup_event_attr[] = {
 	__ATTR(ebook_mode_change, 0600, wackup_event_show, wackup_event_store),
 	__ATTR(wlan, 0600, wackup_event_show, wackup_event_store),
 	__ATTR(ac_power, 0600, wackup_event_show, wackup_event_store),
+	__ATTR(all, 0600, wackup_all_show, wackup_all_store)
 };
 
 static DEFINE_RWLOCK(wackup_event_lock);
@@ -758,6 +762,43 @@ static ssize_t wackup_event_store(struct kobject *s, struct kobj_attribute *attr
 	return n;
 }
 
+static ssize_t wackup_all_show(struct kobject *s, struct kobj_attribute *attr, char *buf) 
+{
+	u8 data;
+
+	read_lock(&wackup_event_lock);
+	olpc_ec_cmd(EC_READ_SCI_MASK, NULL, 0, &data, 1);
+	read_unlock(&wackup_event_lock);
+
+	if (data == 0xff) 
+		return sprintf(buf, "1\n");
+	else
+		return sprintf(buf, "0\n");
+}
+
+static ssize_t wackup_all_store(struct kobject *s, struct kobj_attribute *attr, const char *buf, size_t n)
+{
+	unsigned enabled;
+	u8 data;
+	unsigned char shift = attr - wackup_event_attr;
+
+	if (sscanf(buf, "%d\n", &enabled) != 1)
+		return -EINVAL;
+
+	if (enabled == 1)
+		data = 0xff;
+	else if (!enabled)
+		data = 0;
+	else
+		return -EINVAL;
+
+	write_lock(&wackup_event_lock);
+	olpc_ec_cmd(EC_WRITE_SCI_MASK, &data, 1, NULL, 0);
+	write_unlock(&wackup_event_lock);
+
+	return n;
+}
+
 static struct attribute * olpc_wackup_event_attributes[] = {
 	&wackup_event_attr[0].attr,
 	&wackup_event_attr[1].attr,
@@ -766,6 +807,7 @@ static struct attribute * olpc_wackup_event_attributes[] = {
 	&wackup_event_attr[4].attr,
 	&wackup_event_attr[5].attr,
 	&wackup_event_attr[6].attr,
+	&wackup_event_attr[7].attr,
 	NULL
 };