ANDROID: usb: otg: Temporarily grab wakelock on charger and disconnect events
Change-Id: If995d4af4adcb08e8369009483f2956ad9627267
Signed-off-by: Todd Poynor <toddpoynor@google.com>
diff --git a/drivers/usb/phy/otg-wakelock.c b/drivers/usb/phy/otg-wakelock.c
index 9931626..2f11472 100644
--- a/drivers/usb/phy/otg-wakelock.c
+++ b/drivers/usb/phy/otg-wakelock.c
@@ -21,13 +21,15 @@
#include <linux/spinlock.h>
#include <linux/usb/otg.h>
+#define TEMPORARY_HOLD_TIME 2000
+
static bool enabled = true;
static struct otg_transceiver *otgwl_xceiv;
static struct notifier_block otgwl_nb;
/*
* otgwl_spinlock is held while the VBUS lock is grabbed or dropped and the
- * locked field is updated to match.
+ * held field is updated to match.
*/
static DEFINE_SPINLOCK(otgwl_spinlock);
@@ -39,51 +41,62 @@
struct otgwl_lock {
char name[40];
struct wake_lock wakelock;
- bool locked;
+ bool held;
};
/*
- * VBUS present lock.
+ * VBUS present lock. Also used as a timed lock on charger
+ * connect/disconnect and USB host disconnect, to allow the system
+ * to react to the change in power.
*/
static struct otgwl_lock vbus_lock;
-static void otgwl_grab(struct otgwl_lock *lock)
+static void otgwl_hold(struct otgwl_lock *lock)
{
- if (!lock->locked) {
+ if (!lock->held) {
wake_lock(&lock->wakelock);
- lock->locked = true;
+ lock->held = true;
}
}
+static void otgwl_temporary_hold(struct otgwl_lock *lock)
+{
+ wake_lock_timeout(&lock->wakelock,
+ msecs_to_jiffies(TEMPORARY_HOLD_TIME));
+ lock->held = false;
+}
+
static void otgwl_drop(struct otgwl_lock *lock)
{
- if (lock->locked) {
+ if (lock->held) {
wake_unlock(&lock->wakelock);
- lock->locked = false;
+ lock->held = false;
}
}
-static int otgwl_otg_notifications(struct notifier_block *nb,
- unsigned long event, void *unused)
+static void otgwl_handle_event(unsigned long event)
{
unsigned long irqflags;
- if (!enabled)
- return NOTIFY_OK;
-
spin_lock_irqsave(&otgwl_spinlock, irqflags);
+ if (!enabled) {
+ otgwl_drop(&vbus_lock);
+ spin_unlock_irqrestore(&otgwl_spinlock, irqflags);
+ return;
+ }
+
switch (event) {
case USB_EVENT_VBUS:
case USB_EVENT_ENUMERATED:
- otgwl_grab(&vbus_lock);
+ otgwl_hold(&vbus_lock);
break;
case USB_EVENT_NONE:
case USB_EVENT_ID:
case USB_EVENT_CHARGER:
- otgwl_drop(&vbus_lock);
+ otgwl_temporary_hold(&vbus_lock);
break;
default:
@@ -91,71 +104,25 @@
}
spin_unlock_irqrestore(&otgwl_spinlock, irqflags);
+}
+
+static int otgwl_otg_notifications(struct notifier_block *nb,
+ unsigned long event, void *unused)
+{
+ otgwl_handle_event(event);
return NOTIFY_OK;
}
-static void sync_with_xceiv_state(void)
-{
- if ((otgwl_xceiv->last_event == USB_EVENT_VBUS) ||
- (otgwl_xceiv->last_event == USB_EVENT_ENUMERATED))
- otgwl_grab(&vbus_lock);
- else
- otgwl_drop(&vbus_lock);
-}
-
-static int init_for_xceiv(void)
-{
- int rv;
-
- if (!otgwl_xceiv) {
- otgwl_xceiv = otg_get_transceiver();
-
- if (!otgwl_xceiv) {
- pr_err("%s: No OTG transceiver found\n", __func__);
- return -ENODEV;
- }
-
- snprintf(vbus_lock.name, sizeof(vbus_lock.name), "vbus-%s",
- dev_name(otgwl_xceiv->dev));
- wake_lock_init(&vbus_lock.wakelock, WAKE_LOCK_SUSPEND,
- vbus_lock.name);
-
- rv = otg_register_notifier(otgwl_xceiv, &otgwl_nb);
-
- if (rv) {
- pr_err("%s: otg_register_notifier on transceiver %s"
- " failed\n", __func__,
- dev_name(otgwl_xceiv->dev));
- otgwl_xceiv = NULL;
- wake_lock_destroy(&vbus_lock.wakelock);
- return rv;
- }
- }
-
- return 0;
-}
-
static int set_enabled(const char *val, const struct kernel_param *kp)
{
- unsigned long irqflags;
int rv = param_set_bool(val, kp);
if (rv)
return rv;
- rv = init_for_xceiv();
+ if (otgwl_xceiv)
+ otgwl_handle_event(otgwl_xceiv->last_event);
- if (rv)
- return rv;
-
- spin_lock_irqsave(&otgwl_spinlock, irqflags);
-
- if (enabled)
- sync_with_xceiv_state();
- else
- otgwl_drop(&vbus_lock);
-
- spin_unlock_irqrestore(&otgwl_spinlock, irqflags);
return 0;
}
@@ -169,22 +136,34 @@
static int __init otg_wakelock_init(void)
{
- unsigned long irqflags;
+ int ret;
- otgwl_nb.notifier_call = otgwl_otg_notifications;
+ otgwl_xceiv = otg_get_transceiver();
- if (!init_for_xceiv()) {
- spin_lock_irqsave(&otgwl_spinlock, irqflags);
-
- if (enabled)
- sync_with_xceiv_state();
-
- spin_unlock_irqrestore(&otgwl_spinlock, irqflags);
- } else {
- enabled = false;
+ if (!otgwl_xceiv) {
+ pr_err("%s: No OTG transceiver found\n", __func__);
+ return -ENODEV;
}
- return 0;
+ snprintf(vbus_lock.name, sizeof(vbus_lock.name), "vbus-%s",
+ dev_name(otgwl_xceiv->dev));
+ wake_lock_init(&vbus_lock.wakelock, WAKE_LOCK_SUSPEND,
+ vbus_lock.name);
+
+ otgwl_nb.notifier_call = otgwl_otg_notifications;
+ ret = otg_register_notifier(otgwl_xceiv, &otgwl_nb);
+
+ if (ret) {
+ pr_err("%s: otg_register_notifier on transceiver %s"
+ " failed\n", __func__,
+ dev_name(otgwl_xceiv->dev));
+ otgwl_xceiv = NULL;
+ wake_lock_destroy(&vbus_lock.wakelock);
+ return ret;
+ }
+
+ otgwl_handle_event(otgwl_xceiv->last_event);
+ return ret;
}
late_initcall(otg_wakelock_init);