From mboxrd@z Thu Jan 1 00:00:00 1970 From: Heikki Krogerus Subject: Re: [PATCH v4 08/12] usb: roles: Add usb role switch notifier. Date: Tue, 19 Mar 2019 13:56:51 +0200 Message-ID: <20190319115651.GT7752@kuha.fi.intel.com> References: <20190316035342.77998-1-chenyu56@huawei.com> <20190316035342.77998-9-chenyu56@huawei.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20190316035342.77998-9-chenyu56@huawei.com> Sender: linux-kernel-owner@vger.kernel.org To: Yu Chen Cc: linux-usb@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, 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, Greg Kroah-Hartman , Hans de Goede , Andy Shevchenko List-Id: devicetree@vger.kernel.org On Sat, Mar 16, 2019 at 11:53:38AM +0800, Yu Chen wrote: > 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 c05ffa6abda9..99d8b8e4fe61 100644 > --- a/include/linux/usb/role.h > +++ b/include/linux/usb/role.h > @@ -42,6 +42,8 @@ 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); > @@ -51,5 +53,49 @@ 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 */ Sorry for the late response, but since you are providing a stub for all the functions, not just the new ones, could you please introduce them in a separate patch. Add a patch where you introduce stubs for the exiting functions, and this patch can then add the stubs for just the new notifier functions. thanks, -- heikki