diff options
Diffstat (limited to 'drivers/usb/phy')
| -rw-r--r-- | drivers/usb/phy/Kconfig | 8 | ||||
| -rw-r--r-- | drivers/usb/phy/Makefile | 1 | ||||
| -rw-r--r-- | drivers/usb/phy/otg-wakelock.c | 190 |
3 files changed, 199 insertions, 0 deletions
diff --git a/drivers/usb/phy/Kconfig b/drivers/usb/phy/Kconfig index d5589f9..d5376bc 100644 --- a/drivers/usb/phy/Kconfig +++ b/drivers/usb/phy/Kconfig @@ -6,6 +6,14 @@ menu "USB Physical Layer drivers" config USB_PHY def_bool n +config USB_OTG_WAKELOCK + bool "Hold a wakelock when USB connected" + depends on WAKELOCK + select USB_OTG_UTILS + help + Select this to automatically hold a wakelock when USB is + connected, preventing suspend. + # # USB Transceiver Drivers # diff --git a/drivers/usb/phy/Makefile b/drivers/usb/phy/Makefile index 2135e85..3dff349 100644 --- a/drivers/usb/phy/Makefile +++ b/drivers/usb/phy/Makefile @@ -3,6 +3,7 @@ # obj-$(CONFIG_USB_PHY) += phy.o obj-$(CONFIG_OF) += of.o +obj-$(CONFIG_USB_OTG_WAKELOCK) += otg-wakelock.o # transceiver drivers, keep the list sorted diff --git a/drivers/usb/phy/otg-wakelock.c b/drivers/usb/phy/otg-wakelock.c new file mode 100644 index 0000000..9931626 --- /dev/null +++ b/drivers/usb/phy/otg-wakelock.c @@ -0,0 +1,190 @@ +/* + * otg-wakelock.c + * + * Copyright (C) 2011 Google, Inc. + * + * This software is licensed under the terms of the GNU General Public + * License version 2, as published by the Free Software Foundation, and + * may be copied, distributed, and modified under those terms. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + */ + +#include <linux/kernel.h> +#include <linux/device.h> +#include <linux/notifier.h> +#include <linux/wakelock.h> +#include <linux/spinlock.h> +#include <linux/usb/otg.h> + +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. + */ + +static DEFINE_SPINLOCK(otgwl_spinlock); + +/* + * Only one lock, but since these 3 fields are associated with each other... + */ + +struct otgwl_lock { + char name[40]; + struct wake_lock wakelock; + bool locked; +}; + +/* + * VBUS present lock. + */ + +static struct otgwl_lock vbus_lock; + +static void otgwl_grab(struct otgwl_lock *lock) +{ + if (!lock->locked) { + wake_lock(&lock->wakelock); + lock->locked = true; + } +} + +static void otgwl_drop(struct otgwl_lock *lock) +{ + if (lock->locked) { + wake_unlock(&lock->wakelock); + lock->locked = false; + } +} + +static int otgwl_otg_notifications(struct notifier_block *nb, + unsigned long event, void *unused) +{ + unsigned long irqflags; + + if (!enabled) + return NOTIFY_OK; + + spin_lock_irqsave(&otgwl_spinlock, irqflags); + + switch (event) { + case USB_EVENT_VBUS: + case USB_EVENT_ENUMERATED: + otgwl_grab(&vbus_lock); + break; + + case USB_EVENT_NONE: + case USB_EVENT_ID: + case USB_EVENT_CHARGER: + otgwl_drop(&vbus_lock); + break; + + default: + break; + } + + spin_unlock_irqrestore(&otgwl_spinlock, irqflags); + 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 (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; +} + +static struct kernel_param_ops enabled_param_ops = { + .set = set_enabled, + .get = param_get_bool, +}; + +module_param_cb(enabled, &enabled_param_ops, &enabled, 0644); +MODULE_PARM_DESC(enabled, "enable wakelock when VBUS present"); + +static int __init otg_wakelock_init(void) +{ + unsigned long irqflags; + + otgwl_nb.notifier_call = otgwl_otg_notifications; + + 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; + } + + return 0; +} + +late_initcall(otg_wakelock_init); |