// SPDX-License-Identifier: GPL-2.0+ /* * f_ecm.c -- USB CDC Ethernet (ECM) link function driver * * Copyright (C) 2003-2005,2008 David Brownell * Copyright (C) 2008 Nokia Corporation */ /* #define VERBOSE_DEBUG */ #include <linux/slab.h> #include <linux/kernel.h> #include <linux/module.h> #include <linux/device.h> #include <linux/etherdevice.h> #include "u_ether.h" #include "u_ether_configfs.h" #include "u_ecm.h" /* * This function is a "CDC Ethernet Networking Control Model" (CDC ECM) * Ethernet link. The data transfer model is simple (packets sent and * received over bulk endpoints using normal short packet termination), * and the control model exposes various data and optional notifications. * * ECM is well standardized and (except for Microsoft) supported by most * operating systems with USB host support. It's the preferred interop * solution for Ethernet over USB, at least for firmware based solutions. * (Hardware solutions tend to be more minimalist.) A newer and simpler * "Ethernet Emulation Model" (CDC EEM) hasn't yet caught on. * * Note that ECM requires the use of "alternate settings" for its data * interface. This means that the set_alt() method has real work to do, * and also means that a get_alt() method is required. */ enum ecm_notify_state { … }; struct f_ecm { … }; static inline struct f_ecm *func_to_ecm(struct usb_function *f) { … } /*-------------------------------------------------------------------------*/ /* * Include the status endpoint if we can, even though it's optional. * * Use wMaxPacketSize big enough to fit CDC_NOTIFY_SPEED_CHANGE in one * packet, to simplify cancellation; and a big transfer interval, to * waste less bandwidth. * * Some drivers (like Linux 2.4 cdc-ether!) "need" it to exist even * if they ignore the connect/disconnect notifications that real aether * can provide. More advanced cdc configurations might want to support * encapsulated commands (vendor-specific, using control-OUT). */ #define ECM_STATUS_INTERVAL_MS … #define ECM_STATUS_BYTECOUNT … /* interface descriptor: */ static struct usb_interface_assoc_descriptor ecm_iad_descriptor = …; static struct usb_interface_descriptor ecm_control_intf = …; static struct usb_cdc_header_desc ecm_header_desc = …; static struct usb_cdc_union_desc ecm_union_desc = …; static struct usb_cdc_ether_desc ecm_desc = …; /* the default data interface has no endpoints ... */ static struct usb_interface_descriptor ecm_data_nop_intf = …; /* ... but the "real" data interface has two bulk endpoints */ static struct usb_interface_descriptor ecm_data_intf = …; /* full speed support: */ static struct usb_endpoint_descriptor fs_ecm_notify_desc = …; static struct usb_endpoint_descriptor fs_ecm_in_desc = …; static struct usb_endpoint_descriptor fs_ecm_out_desc = …; static struct usb_descriptor_header *ecm_fs_function[] = …; /* high speed support: */ static struct usb_endpoint_descriptor hs_ecm_notify_desc = …; static struct usb_endpoint_descriptor hs_ecm_in_desc = …; static struct usb_endpoint_descriptor hs_ecm_out_desc = …; static struct usb_descriptor_header *ecm_hs_function[] = …; /* super speed support: */ static struct usb_endpoint_descriptor ss_ecm_notify_desc = …; static struct usb_ss_ep_comp_descriptor ss_ecm_intr_comp_desc = …; static struct usb_endpoint_descriptor ss_ecm_in_desc = …; static struct usb_endpoint_descriptor ss_ecm_out_desc = …; static struct usb_ss_ep_comp_descriptor ss_ecm_bulk_comp_desc = …; static struct usb_descriptor_header *ecm_ss_function[] = …; /* string descriptors: */ static struct usb_string ecm_string_defs[] = …; static struct usb_gadget_strings ecm_string_table = …; static struct usb_gadget_strings *ecm_strings[] = …; /*-------------------------------------------------------------------------*/ static void ecm_do_notify(struct f_ecm *ecm) { … } static void ecm_notify(struct f_ecm *ecm) { … } static void ecm_notify_complete(struct usb_ep *ep, struct usb_request *req) { … } static int ecm_setup(struct usb_function *f, const struct usb_ctrlrequest *ctrl) { … } static int ecm_set_alt(struct usb_function *f, unsigned intf, unsigned alt) { … } /* Because the data interface supports multiple altsettings, * this ECM function *MUST* implement a get_alt() method. */ static int ecm_get_alt(struct usb_function *f, unsigned intf) { … } static void ecm_disable(struct usb_function *f) { … } /*-------------------------------------------------------------------------*/ /* * Callbacks let us notify the host about connect/disconnect when the * net device is opened or closed. * * For testing, note that link states on this side include both opened * and closed variants of: * * - disconnected/unconfigured * - configured but inactive (data alt 0) * - configured and active (data alt 1) * * Each needs to be tested with unplug, rmmod, SET_CONFIGURATION, and * SET_INTERFACE (altsetting). Remember also that "configured" doesn't * imply the host is actually polling the notification endpoint, and * likewise that "active" doesn't imply it's actually using the data * endpoints for traffic. */ static void ecm_open(struct gether *geth) { … } static void ecm_close(struct gether *geth) { … } /*-------------------------------------------------------------------------*/ /* ethernet function driver setup/binding */ static int ecm_bind(struct usb_configuration *c, struct usb_function *f) { … } static inline struct f_ecm_opts *to_f_ecm_opts(struct config_item *item) { … } /* f_ecm_item_ops */ USB_ETHERNET_CONFIGFS_ITEM(…); /* f_ecm_opts_dev_addr */ USB_ETHERNET_CONFIGFS_ITEM_ATTR_DEV_ADDR(…); /* f_ecm_opts_host_addr */ USB_ETHERNET_CONFIGFS_ITEM_ATTR_HOST_ADDR(…); /* f_ecm_opts_qmult */ USB_ETHERNET_CONFIGFS_ITEM_ATTR_QMULT(…); /* f_ecm_opts_ifname */ USB_ETHERNET_CONFIGFS_ITEM_ATTR_IFNAME(…); static struct configfs_attribute *ecm_attrs[] = …; static const struct config_item_type ecm_func_type = …; static void ecm_free_inst(struct usb_function_instance *f) { … } static struct usb_function_instance *ecm_alloc_inst(void) { … } static void ecm_suspend(struct usb_function *f) { … } static void ecm_resume(struct usb_function *f) { … } static void ecm_free(struct usb_function *f) { … } static void ecm_unbind(struct usb_configuration *c, struct usb_function *f) { … } static struct usb_function *ecm_alloc(struct usb_function_instance *fi) { … } DECLARE_USB_FUNCTION_INIT(ecm, ecm_alloc_inst, ecm_alloc); MODULE_DESCRIPTION(…) …; MODULE_LICENSE(…) …; MODULE_AUTHOR(…) …;
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