From: John Stultz <john.stultz@linaro.org>
To: lkml <linux-kernel@vger.kernel.org>
Cc: Yu Chen <chenyu56@huawei.com>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Rob Herring <robh+dt@kernel.org>,
Mark Rutland <mark.rutland@arm.com>,
Heikki Krogerus <heikki.krogerus@linux.intel.com>,
Suzuki K Poulose <suzuki.poulose@arm.com>,
Chunfeng Yun <chunfeng.yun@mediatek.com>,
Felipe Balbi <balbi@kernel.org>,
Hans de Goede <hdegoede@redhat.com>,
Andy Shevchenko <andy.shevchenko@gmail.com>,
Jun Li <lijun.kernel@gmail.com>,
Valentin Schneider <valentin.schneider@arm.com>,
linux-usb@vger.kernel.org, devicetree@vger.kernel.org,
John Stultz <john.stultz@linaro.org>
Subject: [RFC][PATCH 2/3] usb: roles: Add usb role switch notifier.
Date: Wed, 2 Oct 2019 23:16:16 +0000 [thread overview]
Message-ID: <20191002231617.3670-3-john.stultz@linaro.org> (raw)
In-Reply-To: <20191002231617.3670-1-john.stultz@linaro.org>
From: Yu Chen <chenyu56@huawei.com>
This patch adds notifier for drivers want to be informed of the usb role
switch.
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: Chunfeng Yun <chunfeng.yun@mediatek.com>
Cc: Yu Chen <chenyu56@huawei.com>
Cc: Felipe Balbi <balbi@kernel.org>
Cc: Hans de Goede <hdegoede@redhat.com>
Cc: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: Jun Li <lijun.kernel@gmail.com>
Cc: Valentin Schneider <valentin.schneider@arm.com>
Cc: linux-usb@vger.kernel.org
Cc: devicetree@vger.kernel.org
Suggested-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Yu Chen <chenyu56@huawei.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
---
drivers/usb/roles/class.c | 35 ++++++++++++++++++++++++++++++++++-
include/linux/usb/role.h | 16 ++++++++++++++++
2 files changed, 50 insertions(+), 1 deletion(-)
diff --git a/drivers/usb/roles/class.c b/drivers/usb/roles/class.c
index 94b4e7db2b94..418e762d5d72 100644
--- a/drivers/usb/roles/class.c
+++ b/drivers/usb/roles/class.c
@@ -20,6 +20,7 @@ struct usb_role_switch {
struct device dev;
struct mutex lock; /* device lock*/
enum usb_role role;
+ struct blocking_notifier_head nh;
/* From descriptor */
struct device *usb2_port;
@@ -49,8 +50,10 @@ int usb_role_switch_set_role(struct usb_role_switch *sw, enum usb_role role)
mutex_lock(&sw->lock);
ret = sw->set(sw->dev.parent, role);
- if (!ret)
+ if (!ret) {
sw->role = role;
+ blocking_notifier_call_chain(&sw->nh, role, NULL);
+ }
mutex_unlock(&sw->lock);
@@ -58,6 +61,35 @@ int usb_role_switch_set_role(struct usb_role_switch *sw, enum usb_role role)
}
EXPORT_SYMBOL_GPL(usb_role_switch_set_role);
+int usb_role_switch_register_notifier(struct usb_role_switch *sw,
+ struct notifier_block *nb)
+{
+ int ret = blocking_notifier_chain_register(&sw->nh, nb);
+ enum usb_role role;
+
+ if (ret)
+ return ret;
+
+ /* Initialize the notifier that was just registered */
+ mutex_lock(&sw->lock);
+ if (sw->get)
+ role = sw->get(sw->dev.parent);
+ else
+ role = sw->role;
+ blocking_notifier_call_chain(&sw->nh, role, NULL);
+ mutex_unlock(&sw->lock);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(usb_role_switch_register_notifier);
+
+int usb_role_switch_unregister_notifier(struct usb_role_switch *sw,
+ struct notifier_block *nb)
+{
+ return blocking_notifier_chain_unregister(&sw->nh, nb);
+}
+EXPORT_SYMBOL_GPL(usb_role_switch_unregister_notifier);
+
/**
* usb_role_switch_get_role - Get the USB role for a switch
* @sw: USB role switch
@@ -296,6 +328,7 @@ usb_role_switch_register(struct device *parent,
return ERR_PTR(-ENOMEM);
mutex_init(&sw->lock);
+ BLOCKING_INIT_NOTIFIER_HEAD(&sw->nh);
sw->allow_userspace_control = desc->allow_userspace_control;
sw->usb2_port = desc->usb2_port;
diff --git a/include/linux/usb/role.h b/include/linux/usb/role.h
index 2d77f97df72d..8dbf7940b7da 100644
--- a/include/linux/usb/role.h
+++ b/include/linux/usb/role.h
@@ -54,6 +54,10 @@ struct usb_role_switch *
usb_role_switch_register(struct device *parent,
const struct usb_role_switch_desc *desc);
void usb_role_switch_unregister(struct usb_role_switch *sw);
+int usb_role_switch_register_notifier(struct usb_role_switch *sw,
+ struct notifier_block *nb);
+int usb_role_switch_unregister_notifier(struct usb_role_switch *sw,
+ struct notifier_block *nb);
#else
static inline int usb_role_switch_set_role(struct usb_role_switch *sw,
enum usb_role role)
@@ -87,6 +91,18 @@ usb_role_switch_register(struct device *parent,
}
static inline void usb_role_switch_unregister(struct usb_role_switch *sw) { }
+
+static int usb_role_switch_register_notifier(struct usb_role_switch *sw,
+ struct notifier_block *nb)
+{
+ return -ENODEV;
+}
+
+static int usb_role_switch_unregister_notifier(struct usb_role_switch *sw,
+ struct notifier_block *nb)
+{
+ return -ENODEV;
+}
#endif
#endif /* __LINUX_USB_ROLE_H */
--
2.17.1
next prev parent reply other threads:[~2019-10-02 23:16 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-02 23:16 [RFC][PATCH 0/3] dwc3 role-switch handling for HiKey960 John Stultz
2019-10-02 23:16 ` [RFC][PATCH 1/3] dt-bindings: usb: generic: Add role-switch-default-host binding John Stultz
2019-10-02 23:16 ` John Stultz [this message]
2019-10-03 9:25 ` [RFC][PATCH 2/3] usb: roles: Add usb role switch notifier Hans de Goede
2019-10-03 20:37 ` John Stultz
2019-10-03 20:51 ` Hans de Goede
2019-10-04 8:12 ` Heikki Krogerus
2019-10-15 5:39 ` John Stultz
2019-10-16 7:27 ` Hans de Goede
2019-10-18 5:55 ` John Stultz
2019-10-18 8:06 ` Hans de Goede
2019-10-18 18:39 ` John Stultz
2019-10-18 19:30 ` Hans de Goede
2019-10-18 19:53 ` John Stultz
2019-10-18 19:59 ` Hans de Goede
2019-10-18 20:12 ` John Stultz
2019-10-18 20:21 ` Hans de Goede
2019-10-18 20:37 ` John Stultz
2019-10-18 21:05 ` Hans de Goede
2019-10-22 5:58 ` John Stultz
2019-11-14 10:11 ` Hans de Goede
2019-11-15 0:23 ` John Stultz
2019-10-16 9:10 ` Hans de Goede
2019-10-03 11:26 ` Greg Kroah-Hartman
2019-10-03 20:45 ` John Stultz
2019-10-03 20:56 ` Hans de Goede
2019-10-03 21:33 ` John Stultz
2019-10-06 15:22 ` Hans de Goede
2019-10-15 7:03 ` John Stultz
2019-10-04 8:00 ` Heikki Krogerus
2019-10-02 23:16 ` [RFC][PATCH 3/3] usb: dwc3: Registering a role switch in the DRD code John Stultz
2019-10-15 8:25 ` Roger Quadros
2019-10-15 19:10 ` John Stultz
2019-10-16 9:24 ` Roger Quadros
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