From b433c4c789d612cf58739a772bbddbd949bafd20 Mon Sep 17 00:00:00 2001 From: Heikki Krogerus Date: Wed, 7 Apr 2021 09:55:54 +0300 Subject: [PATCH] usb: Iterator for ports 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. Acked-by: Alan Stern Signed-off-by: Heikki Krogerus Link: https://lore.kernel.org/r/20210407065555.88110-4-heikki.krogerus@linux.intel.com Signed-off-by: Greg Kroah-Hartman --- 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 2ce3667..62368c4 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 ddd2f5b..eaae242 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); +#if IS_REACHABLE(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); -- 2.7.4