From mboxrd@z Thu Jan 1 00:00:00 1970 From: Chunfeng Yun Subject: [PATCH 3/5] usb: roles: add API to get usb_role_switch by node Date: Fri, 8 Mar 2019 14:13:40 +0800 Message-ID: <1552025622-15582-4-git-send-email-chunfeng.yun@mediatek.com> References: <1552025622-15582-1-git-send-email-chunfeng.yun@mediatek.com> Mime-Version: 1.0 Content-Type: text/plain Return-path: In-Reply-To: <1552025622-15582-1-git-send-email-chunfeng.yun@mediatek.com> Sender: linux-kernel-owner@vger.kernel.org To: Rob Herring , Greg Kroah-Hartman , Heikki Krogerus Cc: Mark Rutland , Chunfeng Yun , Matthias Brugger , Adam Thomson , Li Jun , Badhri Jagan Sridharan , Hans de Goede , Andy Shevchenko , Min Guo , devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mediatek@lists.infradead.org List-Id: linux-mediatek@lists.infradead.org Add usb_role_switch_get_by_node() to make easier to get usb_role_switch by node which register it. It's useful when there is not device_connection registered between two drivers and only knows the node which register usb_role_switch. Signed-off-by: Chunfeng Yun --- drivers/usb/roles/class.c | 30 ++++++++++++++++++++++++++++++ include/linux/usb/role.h | 1 + 2 files changed, 31 insertions(+) diff --git a/drivers/usb/roles/class.c b/drivers/usb/roles/class.c index 99116af07f1d..284b19856dc4 100644 --- a/drivers/usb/roles/class.c +++ b/drivers/usb/roles/class.c @@ -11,6 +11,7 @@ #include #include #include +#include #include static struct class *role_class; @@ -121,6 +122,35 @@ struct usb_role_switch *usb_role_switch_get(struct device *dev) } EXPORT_SYMBOL_GPL(usb_role_switch_get); +static int __switch_match_node(struct device *dev, const void *node) +{ + return dev->parent->of_node == (const struct device_node *)node; +} + +/** + * usb_role_switch_get_by_node - Find USB role switch by it's parent node + * @node: The node that register USB role switch + * + * Finds and returns role switch registered by @node. The reference count + * for the found switch is incremented. + */ +struct usb_role_switch *usb_role_switch_get_by_node(struct device_node *node) +{ + struct usb_role_switch *sw; + struct device *dev; + + dev = class_find_device(role_class, NULL, node, + __switch_match_node); + 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(usb_role_switch_get_by_node); + /** * 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 edc51be4a77c..056498b83dee 100644 --- a/include/linux/usb/role.h +++ b/include/linux/usb/role.h @@ -42,6 +42,7 @@ struct usb_role_switch_desc { 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_by_node(struct device_node *node); struct usb_role_switch *usb_role_switch_get(struct device *dev); void usb_role_switch_put(struct usb_role_switch *sw); -- 2.20.1