From: Todd Poynor <toddpoynor@xxxxxxxxxx>
usb: phy: Hold wakeupsource when USB is enumerated in peripheral mode
Purpose of this is to prevent the system to enter into suspend state from USB
peripheral traffic by hodling a wakeupsource when USB is connected and
enumerated in peripheral mode(say adb).
Disabled by default, can enable with:
echo Y > /sys/module/otg_wakeupsource/parameters/enabled
Cc: Felipe Balbi <balbi@xxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Cc: linux-kernel@xxxxxxxxxxxxxxx
Cc: linux-usb@xxxxxxxxxxxxxxx
Cc: Android Kernel Team <kernel-team@xxxxxxxxxxx>
Cc: John Stultz <john.stultz@xxxxxxxxxx>
Cc: Sumit Semwal <sumit.semwal@xxxxxxxxxx>
Cc: Arve Hj��<arve@xxxxxxxxxxx>
Cc: Benoit Goby <benoit@xxxxxxxxxxx>
Signed-off-by: Todd Poynor <toddpoynor@xxxxxxxxxx>
[kiran: Added context to commit message, squished build fixes
from Benoit Goby and Arve Hj�� changed wakelocks usage
to wakeupsource, merged Todd's refactoring logic and simplified
the structures and code and addressed community feedback]
Signed-off-by: Kiran Raparthy <kiran.kumar@xxxxxxxxxx>
---
v3:
* As per the feedback,no global phy pointer used.
* called the one-liner wakeupsource handling calls
directly instead of indirect functions implemented in v2.
* Removed indirect function get_phy_hook and used usb_get_phy
to get the phy handle..
v2:
* wakeupsource handling implemeted per-PHY
* Implemented wakeupsource handling calls in phy
* included Todd's refactoring logic.
v1:
* changed to "disabled by default" from "enable by default".
* Kconfig help text modified
* Included better commit text
* otgws_nb moved to otg_wakeupsource_init function
* Introduced get_phy_hook to handle otgws_xceiv per-PHY
RFC:
* Included build fix from Benoit Goby and Arve Hj��* Removed lock->held field in driver as this mechanism is
provided in wakeupsource driver.
* wakelock(wl) terminology replaced with wakeup_source(ws).
drivers/usb/phy/Kconfig | 8 +++
drivers/usb/phy/Makefile | 1 +
drivers/usb/phy/otg-wakeupsource.c | 136 +++++++++++++++++++++++++++++++++++++
include/linux/usb/phy.h | 4 ++
4 files changed, 149 insertions(+)
create mode 100644 drivers/usb/phy/otg-wakeupsource.c
diff --git a/drivers/usb/phy/Kconfig b/drivers/usb/phy/Kconfig
index e253fa0..d9ddd85 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 wakeupsource when USB is enumerated in peripheral mode"
+ depends on PM_SLEEP
+ select USB_PHY
+ help
+ Prevent the system going into automatic suspend while
+ it is attached as a USB peripheral by holding a wakeupsource.
+
#
# 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..d9a1720
--- /dev/null
+++ b/drivers/usb/phy/otg-wakeupsource.c
@@ -0,0 +1,136 @@
+/*
+ * 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>
+
+bool enabled = false;
+
+static DEFINE_SPINLOCK(otgws_spinlock);
+
+static void otgws_handle_event(struct usb_phy *otgws_xceiv, unsigned long event)
+{
+ unsigned long irqflags;
+
+ spin_lock_irqsave(&otgws_spinlock, irqflags);
+
+ if (!enabled) {
+ __pm_relax(&otgws_xceiv->wsource);
+ spin_unlock_irqrestore(&otgws_spinlock, irqflags);
+ return;
+ }
+
+ switch (event) {
+ case USB_EVENT_VBUS:
+ case USB_EVENT_ENUMERATED:
+ __pm_stay_awake(&otgws_xceiv->wsource);
+ break;
+
+ case USB_EVENT_NONE:
+ case USB_EVENT_ID:
+ case USB_EVENT_CHARGER:
+ __pm_relax(&otgws_xceiv->wsource);
+ break;
+
+ default:
+ break;
+ }
+
+ spin_unlock_irqrestore(&otgws_spinlock, irqflags);
+}
+
+static int otgws_otg_notifications(struct notifier_block *nb,
+ unsigned long event, void *unused)
+{
+ static struct usb_phy *otgws_xceiv;
+
+ otgws_xceiv = usb_get_phy(USB_PHY_TYPE_USB2);
+
+ if (IS_ERR(otgws_xceiv)) {
+ pr_err("%s: No OTG transceiver found\n", __func__);
+ return PTR_ERR(otgws_xceiv);
+ }
+
+ otgws_handle_event(otgws_xceiv, event);
+
+ return NOTIFY_OK;
+}
+
+static int set_enabled(const char *val, const struct kernel_param *kp)
+{
+ int rv = param_set_bool(val, kp);
+ static struct usb_phy *otgws_xceiv;
+
+ if (rv)
+ return rv;
+
+ otgws_xceiv = usb_get_phy(USB_PHY_TYPE_USB2);
+
+ if (IS_ERR(otgws_xceiv)) {
+ pr_err("%s: No OTG transceiver found\n", __func__);
+ return PTR_ERR(otgws_xceiv);
+ }
+
+ otgws_handle_event(otgws_xceiv, otgws_xceiv->last_event);
+
+ 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)
+{
+ int ret;
+ char wsource_name[40];
+ static struct usb_phy *otgws_xceiv;
+
+ otgws_xceiv = usb_get_phy(USB_PHY_TYPE_USB2);
+
+ if (IS_ERR(otgws_xceiv)) {
+ pr_err("%s: No OTG transceiver found\n", __func__);
+ return PTR_ERR(otgws_xceiv);
+ }
+
+ snprintf(wsource_name, sizeof(wsource_name), "vbus-%s",
+ dev_name(otgws_xceiv->dev));
+ wakeup_source_init(&otgws_xceiv->wsource, wsource_name);
+
+ otgws_xceiv->otgws_nb.notifier_call = otgws_otg_notifications;
+ ret = usb_register_notifier(otgws_xceiv, &otgws_xceiv->otgws_nb);
+
+ if (ret) {
+ pr_err("%s: usb_register_notifier on transceiver %s failed\n",
+ __func__, dev_name(otgws_xceiv->dev));
+ wakeup_source_trash(&otgws_xceiv->wsource);
+ otgws_xceiv = NULL;
+ return ret;
+ }
+
+ return 0;
+}
+
+late_initcall(otg_wakeupsource_init);
diff --git a/include/linux/usb/phy.h b/include/linux/usb/phy.h
index 353053a..c71cf15 100644
--- a/include/linux/usb/phy.h
+++ b/include/linux/usb/phy.h
@@ -88,6 +88,10 @@ struct usb_phy {
/* for notification of usb_phy_events */
struct atomic_notifier_head notifier;
+ struct notifier_block otgws_nb;
+
+ /* wakeup source */
+ struct wakeup_source wsource;
/* to pass extra port status to the root hub */
u16 port_status;
--
1.8.2.1
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