Introducing usb_for_each_port(). It works the same way as usb_for_each_dev(), but instead of going through every USB device in the system, it walks through the USB ports in the system.
Signed-off-by: Heikki Krogerus <heikki.kroge...@linux.intel.com> Acked-by: Alan Stern <st...@rowland.harvard.edu> --- drivers/usb/core/usb.c | 46 ++++++++++++++++++++++++++++++++++++++++++ include/linux/usb.h | 9 +++++++++ 2 files changed, 55 insertions(+) diff --git a/drivers/usb/core/usb.c b/drivers/usb/core/usb.c index 2ce3667ec6fae..62368c4ed37af 100644 --- a/drivers/usb/core/usb.c +++ b/drivers/usb/core/usb.c @@ -398,6 +398,52 @@ int usb_for_each_dev(void *data, int (*fn)(struct usb_device *, void *)) } EXPORT_SYMBOL_GPL(usb_for_each_dev); +struct each_hub_arg { + void *data; + int (*fn)(struct device *, void *); +}; + +static int __each_hub(struct usb_device *hdev, void *data) +{ + struct each_hub_arg *arg = (struct each_hub_arg *)data; + struct usb_hub *hub; + int ret = 0; + int i; + + hub = usb_hub_to_struct_hub(hdev); + if (!hub) + return 0; + + mutex_lock(&usb_port_peer_mutex); + + for (i = 0; i < hdev->maxchild; i++) { + ret = arg->fn(&hub->ports[i]->dev, arg->data); + if (ret) + break; + } + + mutex_unlock(&usb_port_peer_mutex); + + return ret; +} + +/** + * usb_for_each_port - interate over all USB ports in the system + * @data: data pointer that will be handed to the callback function + * @fn: callback function to be called for each USB port + * + * Iterate over all USB ports and call @fn for each, passing it @data. If it + * returns anything other than 0, we break the iteration prematurely and return + * that value. + */ +int usb_for_each_port(void *data, int (*fn)(struct device *, void *)) +{ + struct each_hub_arg arg = {data, fn}; + + return usb_for_each_dev(&arg, __each_hub); +} +EXPORT_SYMBOL_GPL(usb_for_each_port); + /** * usb_release_dev - free a usb device structure when all users of it are finished. * @dev: device that's been disconnected diff --git a/include/linux/usb.h b/include/linux/usb.h index ddd2f5b2a2827..ebcd03d835d04 100644 --- a/include/linux/usb.h +++ b/include/linux/usb.h @@ -882,6 +882,15 @@ extern struct usb_host_interface *usb_find_alt_setting( unsigned int iface_num, unsigned int alt_num); +#ifdef CONFIG_USB +int usb_for_each_port(void *data, int (*fn)(struct device *, void *)); +#else +static inline int usb_for_each_port(void *data, int (*fn)(struct device *, void *)) +{ + return 0; +} +#endif + /* port claiming functions */ int usb_hub_claim_port(struct usb_device *hdev, unsigned port1, struct usb_dev_state *owner); -- 2.30.2