From mboxrd@z Thu Jan 1 00:00:00 1970 From: Yu Chen Subject: [PATCH v2 06/10] usb: roles: Add usb role switch notifier. Date: Mon, 18 Feb 2019 19:23:06 +0800 Message-ID: <20190218112310.17860-7-chenyu56@huawei.com> References: <20190218112310.17860-1-chenyu56@huawei.com> Mime-Version: 1.0 Content-Type: text/plain Return-path: In-Reply-To: <20190218112310.17860-1-chenyu56@huawei.com> Sender: linux-kernel-owner@vger.kernel.org To: linux-usb@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org Cc: john.stultz@linaro.org, suzhuangluan@hisilicon.com, kongfei@hisilicon.com, liuyu712@hisilicon.com, wanghu17@hisilicon.com, butao@hisilicon.com, chenyao11@huawei.com, fangshengzhou@hisilicon.com, lipengcheng8@huawei.com, songxiaowei@hisilicon.com, xuyiping@hisilicon.com, xuyoujun4@huawei.com, yudongbin@hisilicon.com, zangleigang@hisilicon.com, Yu Chen , Greg Kroah-Hartman , Heikki Krogerus , Hans de Goede , Andy Shevchenko List-Id: devicetree@vger.kernel.org This patch adds notifier for drivers want to be informed of the usb role switch. Cc: Greg Kroah-Hartman Cc: Heikki Krogerus Cc: Hans de Goede Cc: Andy Shevchenko Cc: John Stultz Suggested-by: Heikki Krogerus Signed-off-by: Yu Chen --- drivers/usb/roles/class.c | 20 +++++++++++++++++++- include/linux/usb/role.h | 46 ++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 65 insertions(+), 1 deletion(-) diff --git a/drivers/usb/roles/class.c b/drivers/usb/roles/class.c index f45d8df5cfb8..e2caaa665d6e 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 +61,20 @@ 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) +{ + return blocking_notifier_chain_register(&sw->nh, nb); +} +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 @@ -271,6 +288,7 @@ 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 9684a8734757..9e1ca663387a 100644 --- a/include/linux/usb/role.h +++ b/include/linux/usb/role.h @@ -41,6 +41,8 @@ struct usb_role_switch_desc { bool allow_userspace_control; }; + +#if IS_ENABLED(CONFIG_USB_ROLE_SWITCH) int usb_role_switch_set_role(struct usb_role_switch *sw, enum usb_role role); enum usb_role usb_role_switch_get_role(struct usb_role_switch *sw); struct usb_role_switch *usb_role_switch_get(struct device *dev); @@ -50,5 +52,49 @@ 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) +{ + return 0; +} + +static inline enum usb_role usb_role_switch_get_role(struct usb_role_switch *sw) +{ + return USB_ROLE_NONE; +} + +static inline struct usb_role_switch *usb_role_switch_get(struct device *dev) +{ + return ERR_PTR(-ENODEV); +} + +static inline void usb_role_switch_put(struct usb_role_switch *sw) { } + +static inline struct usb_role_switch * +usb_role_switch_register(struct device *parent, + const struct usb_role_switch_desc *desc) +{ + return ERR_PTR(-ENODEV); +} + +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 */ -- 2.15.0-rc2