From mboxrd@z Thu Jan 1 00:00:00 1970 From: Chunfeng Yun Subject: Re: [v3 PATCH 4/6] usb: roles: add API to get usb_role_switch by node Date: Thu, 11 Apr 2019 11:11:09 +0800 Message-ID: <1554952269.10179.185.camel@mhfsdcap03> References: <1554257354-7440-1-git-send-email-chunfeng.yun@mediatek.com> <1554257354-7440-5-git-send-email-chunfeng.yun@mediatek.com> <20190410102239.GG20058@kuha.fi.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20190410102239.GG20058@kuha.fi.intel.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=m.gmane.org@lists.infradead.org To: Heikki Krogerus Cc: Mark Rutland , devicetree@vger.kernel.org, Hans de Goede , Greg Kroah-Hartman , linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, Badhri Jagan Sridharan , Andy Shevchenko , Rob Herring , Alan Stern , Min Guo , Matthias Brugger , linux-mediatek@lists.infradead.org, Adam Thomson , linux-arm-kernel@lists.infradead.org, Li Jun List-Id: devicetree@vger.kernel.org On Wed, 2019-04-10 at 13:22 +0300, Heikki Krogerus wrote: > On Wed, Apr 03, 2019 at 10:09:12AM +0800, Chunfeng Yun wrote: > > Add fwnode_usb_role_switch_get() to make easier to get > > usb_role_switch by fwnode which register it. > > It's useful when there is not device_connection registered > > between two drivers and only knows the fwnode which register > > usb_role_switch. > > > > Signed-off-by: Chunfeng Yun > > --- > > v3 changes: > > 1. use fwnodes instead of node suggested by Andy > > 2. rebuild the API suggested by Heikki > > > > v2 no changes > > --- > > drivers/usb/roles/class.c | 31 +++++++++++++++++++++++++++++++ > > include/linux/usb/role.h | 2 ++ > > 2 files changed, 33 insertions(+) > > > > diff --git a/drivers/usb/roles/class.c b/drivers/usb/roles/class.c > > index f45d8df5cfb8..5ecb57f8960b 100644 > > --- a/drivers/usb/roles/class.c > > +++ b/drivers/usb/roles/class.c > > @@ -12,6 +12,7 @@ > > #include > > #include > > #include > > +#include > > #include > > > > static struct class *role_class; > > @@ -135,6 +136,36 @@ struct usb_role_switch *usb_role_switch_get(struct device *dev) > > } > > EXPORT_SYMBOL_GPL(usb_role_switch_get); > > > > +static int __switch_match_fwnode(struct device *dev, const void *fwnode) > > +{ > > + return dev_fwnode(dev->parent) == (const struct fwnode_handle *)fwnode; > > +} > > I don't think this is actually needed. Yes, you are right > Why not just assign the > parent's fwnode for the mux as well? will do it in next version > > I'll add an example to the patch 6/6 in this series. > > > +/** > > + * fwnode_usb_role_switch_get - Find USB role switch by it's parent fwnode > > + * @fwnode: The fwnode that register USB role switch > > + * > > + * Finds and returns role switch registered by @fwnode. The reference count > > + * for the found switch is incremented. > > + */ > > +struct usb_role_switch * > > +fwnode_usb_role_switch_get(struct fwnode_handle *fwnode) > > +{ > > + struct usb_role_switch *sw; > > + struct device *dev; > > + > > + dev = class_find_device(role_class, NULL, fwnode, > > + __switch_match_fwnode); > > So here you can then reuse switch_fwnode_match(): > > dev = class_find_device(role_class, NULL, fwnode, switch_fwnode_match); I make a fast test, it works, thanks a lot Heikki > > > + if (!dev) > > + return ERR_PTR(-EPROBE_DEFER); > > + > > + sw = to_role_switch(dev); > > + WARN_ON(!try_module_get(sw->dev.parent->driver->owner)); > > + > > + return sw; > > +} > > +EXPORT_SYMBOL_GPL(fwnode_usb_role_switch_get); > > + > > /** > > * usb_role_switch_put - Release handle to a switch > > * @sw: USB Role Switch > > diff --git a/include/linux/usb/role.h b/include/linux/usb/role.h > > index c05ffa6abda9..d21cd55d9e45 100644 > > --- a/include/linux/usb/role.h > > +++ b/include/linux/usb/role.h > > @@ -46,6 +46,8 @@ 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); > > void usb_role_switch_put(struct usb_role_switch *sw); > > +struct usb_role_switch * > > +fwnode_usb_role_switch_get(struct fwnode_handle *fwnode); > > > > struct usb_role_switch * > > usb_role_switch_register(struct device *parent, > > -- > > 2.20.1 > > thanks, >