From mboxrd@z Thu Jan 1 00:00:00 1970 From: Chen Yu Subject: Re: [PATCH v1 08/12] usb: roles: Add usb role switch notifier. Date: Tue, 4 Dec 2018 09:07:08 +0800 Message-ID: References: <20181203034515.91412-1-chenyu56@huawei.com> <20181203034515.91412-9-chenyu56@huawei.com> <20181203123824.GE24338@kuha.fi.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: <20181203123824.GE24338@kuha.fi.intel.com> Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org To: Heikki Krogerus Cc: wangbinghui@hisilicon.com, linux-usb@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, suzhuangluan@hisilicon.com, kongfei@hisilicon.com, Greg Kroah-Hartman , Hans de Goede , Andy Shevchenko , John Stultz List-Id: devicetree@vger.kernel.org On 2018/12/3 20:38, Heikki Krogerus wrote: > On Mon, Dec 03, 2018 at 11:45:11AM +0800, Yu Chen wrote: >> This patch adds notifier for drivers want to be informed of the usb role switch. > > I think in this case it would be good to explain a little for what we > need the notifier for. > >> Cc: Greg Kroah-Hartman >> Cc: Heikki Krogerus >> Cc: Hans de Goede >> Cc: Andy Shevchenko >> Cc: John Stultz >> Signed-off-by: Heikki Krogerus >> Signed-off-by: Yu Chen >> >> -- >> v0: >> The patch is provided by Heikki Krogerus. I modified and test it >> on Hikey960 platform. > > I don't think I actually made a "patch" for this. The "diff" I made > showing the idea does not count, so you should not sign off the patch > with my address. > > In this case I believe something like "Suggested-by" should be used > instead of SoB tag: > > Suggested-by: Heikki Krogerus > > Side note: If this was from me, then there should be "from" line with > my address as well. > OK. Thanks！ >> -- >> --- >> drivers/usb/common/roles.c | 20 +++++++++++++++++++- >> include/linux/usb/role.h | 46 ++++++++++++++++++++++++++++++++++++++++++++++ >> 2 files changed, 65 insertions(+), 1 deletion(-) >> >> diff --git a/drivers/usb/common/roles.c b/drivers/usb/common/roles.c >> index 0f48090c5c30..bfd7a988b64c 100644 >> --- a/drivers/usb/common/roles.c >> +++ b/drivers/usb/common/roles.c >> @@ -21,6 +21,7 @@ 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; >> @@ -50,8 +51,10 @@ 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); >> >> @@ -59,6 +62,20 @@ 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 >> @@ -297,6 +314,7 @@ 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 edc51be4a77c..c97d4be91ada 100644 >> --- a/include/linux/usb/role.h >> +++ b/include/linux/usb/role.h >> @@ -40,6 +40,8 @@ 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); >> @@ -49,5 +51,49 @@ 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 > > thanks, >