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Date: Fri, 22 Aug 2014 15:19:32 +0530
From: Kiran Kumar Raparthy <kiran.kumar@...aro.org>
To: linux-kernel@...r.kernel.org
Cc: Todd Poynor <toddpoynor@...gle.com>, Felipe Balbi <balbi@...com>,
Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
linux-usb@...r.kernel.org,
Android Kernel Team <kernel-team@...roid.com>,
John Stultz <john.stultz@...aro.org>,
Arve Hjønnevåg <arve@...roid.com>,
Benoit Goby <benoit@...roid.com>,
Kiran Raparthy <kiran.kumar@...aro.org>
Subject: [RFC 1/2] USB: OTG: Hold wakeupsource when VBUS present
From: Todd Poynor <toddpoynor@...gle.com>
USB: OTG: Hold wakeupsource when VBUS present
Enabled by default, can disable with:
echo N > /sys/module/otg_wakeupsource/parameters/enabled
This is one of the number of patches from the Android AOSP common.git tree,
which is used on almost all Android devices. so I wanted to submit it for
review to see if it should go upstream.
Cc: Felipe Balbi <balbi@...com>
Cc: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Cc: linux-kernel@...r.kernel.org
Cc: linux-usb@...r.kernel.org
Cc: Android Kernel Team <kernel-team@...roid.com>
Cc: John Stultz <john.stultz@...aro.org>
Cc: Arve Hjønnevåg <arve@...roid.com>
Cc: Benoit Goby <benoit@...roid.com>
Signed-off-by: Todd Poynor <toddpoynor@...gle.com>
Signed-off-by: Kiran Raparthy <kiran.kumar@...aro.org>
[kiran: Added context to commit message
Included build fix from Benoit Goby and Arve Arve Hjønnevåg
Removed lock->held field in driver as this mechanism is provided in wakeup.c
wakelock(wl) terminology replaced with wakeup_source(ws)
sys entry(module param) field modified to otg_wakeupsource
__pm_stay_awake and __pm_relax called directly from the main
code instead of calling them via otgws_grab,otgws_drop]
---
drivers/usb/phy/Kconfig | 8 ++
drivers/usb/phy/Makefile | 1 +
drivers/usb/phy/otg-wakeupsource.c | 171 +++++++++++++++++++++++++++++++++++++
3 files changed, 180 insertions(+)
create mode 100644 drivers/usb/phy/otg-wakeupsource.c
diff --git a/drivers/usb/phy/Kconfig b/drivers/usb/phy/Kconfig
index e253fa0..9c747b2 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_WAKEUPSOURCE
+ bool "Hold a wakeupsource when USB connected"
+ depends on PM_SLEEP
+ select USB_PHY
+ help
+ Select this to automatically hold a wakeupsource when USB is
+ connected, preventing suspend.
+
#
# USB Transceiver Drivers
#
diff --git a/drivers/usb/phy/Makefile b/drivers/usb/phy/Makefile
index 24a9133..ca2fbaf 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_WAKEUPSOURCE) += otg-wakeupsource.o
# transceiver drivers, keep the list sorted
diff --git a/drivers/usb/phy/otg-wakeupsource.c b/drivers/usb/phy/otg-wakeupsource.c
new file mode 100644
index 0000000..fa44e11
--- /dev/null
+++ b/drivers/usb/phy/otg-wakeupsource.c
@@ -0,0 +1,171 @@
+/*
+ * otg-wakeupsource.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/module.h>
+#include <linux/notifier.h>
+#include <linux/pm_wakeup.h>
+#include <linux/spinlock.h>
+#include <linux/usb/otg.h>
+
+static bool enabled = true;
+static struct usb_phy *otgws_xceiv;
+static struct notifier_block otgws_nb;
+
+
+static DEFINE_SPINLOCK(otgws_spinlock);
+
+/*
+ * Only one lock, but since these 2 fields are associated with each other...
+ */
+
+struct otgws_lock {
+ char name[40];
+ struct wakeup_source wsource;
+};
+
+/*
+ * VBUS present lock.
+ */
+
+static struct otgws_lock vbus_lock;
+
+static int otgws_otg_notifications(struct notifier_block *nb,
+ unsigned long event, void *unused)
+{
+ unsigned long irqflags;
+
+ if (!enabled)
+ return NOTIFY_OK;
+
+ spin_lock_irqsave(&otgws_spinlock, irqflags);
+
+ switch (event) {
+ case USB_EVENT_VBUS:
+ case USB_EVENT_ENUMERATED:
+ __pm_stay_awake(&vbus_lock.wsource);
+ break;
+
+ case USB_EVENT_NONE:
+ case USB_EVENT_ID:
+ case USB_EVENT_CHARGER:
+ __pm_relax(&vbus_lock.wsource);
+ break;
+
+ default:
+ break;
+ }
+
+ spin_unlock_irqrestore(&otgws_spinlock, irqflags);
+ return NOTIFY_OK;
+}
+
+static void sync_with_xceiv_state(void)
+{
+ if ((otgws_xceiv->last_event == USB_EVENT_VBUS) ||
+ (otgws_xceiv->last_event == USB_EVENT_ENUMERATED))
+ __pm_stay_awake(&vbus_lock.wsource);
+ else
+ __pm_relax(&vbus_lock.wsource);
+}
+
+static int init_for_xceiv(void)
+{
+ int rv;
+ struct usb_phy *phy;
+
+ if (!otgws_xceiv) {
+ phy = usb_get_phy(USB_PHY_TYPE_USB2);
+
+ if (IS_ERR(phy)) {
+ pr_err("%s: No USB transceiver found\n", __func__);
+ return PTR_ERR(phy);
+ }
+ otgws_xceiv = phy;
+
+ snprintf(vbus_lock.name, sizeof(vbus_lock.name), "vbus-%s",
+ dev_name(otgws_xceiv->dev));
+ wakeup_source_init(&vbus_lock.wsource, vbus_lock.name);
+
+ rv = usb_register_notifier(otgws_xceiv, &otgws_nb);
+
+ if (rv) {
+ pr_err("%s: usb_register_notifier on transceiver %s
+ failed\n", __func__,
+ dev_name(otgws_xceiv->dev));
+ otgws_xceiv = NULL;
+ wakeup_source_trash(&vbus_lock.wsource);
+ 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(&otgws_spinlock, irqflags);
+
+ if (enabled)
+ sync_with_xceiv_state();
+ else
+ __pm_relax(&vbus_lock.wsource);
+
+ spin_unlock_irqrestore(&otgws_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, "Hold wakeupsource when VBUS present");
+
+static int __init otg_wakeupsource_init(void)
+{
+ unsigned long irqflags;
+
+ otgws_nb.notifier_call = otgws_otg_notifications;
+
+ if (!init_for_xceiv()) {
+ spin_lock_irqsave(&otgws_spinlock, irqflags);
+
+ if (enabled)
+ sync_with_xceiv_state();
+
+ spin_unlock_irqrestore(&otgws_spinlock, irqflags);
+ } else {
+ enabled = false;
+ }
+
+ return 0;
+}
+
+late_initcall(otg_wakeupsource_init);
--
1.8.2.1
--
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