507 lines
14 KiB
C
507 lines
14 KiB
C
// SPDX-License-Identifier: GPL-2.0+
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/*
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* f_subset.c -- "CDC Subset" Ethernet link function driver
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*
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* Copyright (C) 2003-2005,2008 David Brownell
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* Copyright (C) 2008 Nokia Corporation
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*/
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#include <linux/slab.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/device.h>
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#include <linux/etherdevice.h>
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#include "u_ether.h"
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#include "u_ether_configfs.h"
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#include "u_gether.h"
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/*
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* This function packages a simple "CDC Subset" Ethernet port with no real
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* control mechanisms; just raw data transfer over two bulk endpoints.
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* The data transfer model is exactly that of CDC Ethernet, which is
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* why we call it the "CDC Subset".
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*
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* Because it's not standardized, this has some interoperability issues.
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* They mostly relate to driver binding, since the data transfer model is
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* so simple (CDC Ethernet). The original versions of this protocol used
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* specific product/vendor IDs: byteswapped IDs for Digital Equipment's
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* SA-1100 "Itsy" board, which could run Linux 2.4 kernels and supported
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* daughtercards with USB peripheral connectors. (It was used more often
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* with other boards, using the Itsy identifiers.) Linux hosts recognized
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* this with CONFIG_USB_ARMLINUX; these devices have only one configuration
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* and one interface.
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*
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* At some point, MCCI defined a (nonconformant) CDC MDLM variant called
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* "SAFE", which happens to have a mode which is identical to the "CDC
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* Subset" in terms of data transfer and lack of control model. This was
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* adopted by later Sharp Zaurus models, and by some other software which
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* Linux hosts recognize with CONFIG_USB_NET_ZAURUS.
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*
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* Because Microsoft's RNDIS drivers are far from robust, we added a few
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* descriptors to the CDC Subset code, making this code look like a SAFE
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* implementation. This lets you use MCCI's host side MS-Windows drivers
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* if you get fed up with RNDIS. It also makes it easier for composite
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* drivers to work, since they can use class based binding instead of
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* caring about specific product and vendor IDs.
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*/
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struct f_gether {
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struct gether port;
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char ethaddr[14];
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};
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static inline struct f_gether *func_to_geth(struct usb_function *f)
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{
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return container_of(f, struct f_gether, port.func);
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}
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/*-------------------------------------------------------------------------*/
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/*
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* "Simple" CDC-subset option is a simple vendor-neutral model that most
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* full speed controllers can handle: one interface, two bulk endpoints.
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* To assist host side drivers, we fancy it up a bit, and add descriptors so
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* some host side drivers will understand it as a "SAFE" variant.
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*
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* "SAFE" loosely follows CDC WMC MDLM, violating the spec in various ways.
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* Data endpoints live in the control interface, there's no data interface.
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* And it's not used to talk to a cell phone radio.
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*/
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/* interface descriptor: */
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static struct usb_interface_descriptor subset_data_intf = {
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.bLength = sizeof subset_data_intf,
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.bDescriptorType = USB_DT_INTERFACE,
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/* .bInterfaceNumber = DYNAMIC */
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.bAlternateSetting = 0,
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.bNumEndpoints = 2,
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.bInterfaceClass = USB_CLASS_COMM,
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.bInterfaceSubClass = USB_CDC_SUBCLASS_MDLM,
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.bInterfaceProtocol = 0,
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/* .iInterface = DYNAMIC */
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};
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static struct usb_cdc_header_desc mdlm_header_desc = {
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.bLength = sizeof mdlm_header_desc,
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.bDescriptorType = USB_DT_CS_INTERFACE,
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.bDescriptorSubType = USB_CDC_HEADER_TYPE,
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.bcdCDC = cpu_to_le16(0x0110),
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};
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static struct usb_cdc_mdlm_desc mdlm_desc = {
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.bLength = sizeof mdlm_desc,
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.bDescriptorType = USB_DT_CS_INTERFACE,
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.bDescriptorSubType = USB_CDC_MDLM_TYPE,
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.bcdVersion = cpu_to_le16(0x0100),
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.bGUID = {
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0x5d, 0x34, 0xcf, 0x66, 0x11, 0x18, 0x11, 0xd6,
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0xa2, 0x1a, 0x00, 0x01, 0x02, 0xca, 0x9a, 0x7f,
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},
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};
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/* since "usb_cdc_mdlm_detail_desc" is a variable length structure, we
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* can't really use its struct. All we do here is say that we're using
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* the submode of "SAFE" which directly matches the CDC Subset.
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*/
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static u8 mdlm_detail_desc[] = {
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6,
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USB_DT_CS_INTERFACE,
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USB_CDC_MDLM_DETAIL_TYPE,
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0, /* "SAFE" */
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0, /* network control capabilities (none) */
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0, /* network data capabilities ("raw" encapsulation) */
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};
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static struct usb_cdc_ether_desc ether_desc = {
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.bLength = sizeof ether_desc,
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.bDescriptorType = USB_DT_CS_INTERFACE,
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.bDescriptorSubType = USB_CDC_ETHERNET_TYPE,
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/* this descriptor actually adds value, surprise! */
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/* .iMACAddress = DYNAMIC */
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.bmEthernetStatistics = cpu_to_le32(0), /* no statistics */
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.wMaxSegmentSize = cpu_to_le16(ETH_FRAME_LEN),
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.wNumberMCFilters = cpu_to_le16(0),
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.bNumberPowerFilters = 0,
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};
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/* full speed support: */
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static struct usb_endpoint_descriptor fs_subset_in_desc = {
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.bLength = USB_DT_ENDPOINT_SIZE,
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.bDescriptorType = USB_DT_ENDPOINT,
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.bEndpointAddress = USB_DIR_IN,
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.bmAttributes = USB_ENDPOINT_XFER_BULK,
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};
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static struct usb_endpoint_descriptor fs_subset_out_desc = {
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.bLength = USB_DT_ENDPOINT_SIZE,
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.bDescriptorType = USB_DT_ENDPOINT,
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.bEndpointAddress = USB_DIR_OUT,
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.bmAttributes = USB_ENDPOINT_XFER_BULK,
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};
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static struct usb_descriptor_header *fs_eth_function[] = {
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(struct usb_descriptor_header *) &subset_data_intf,
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(struct usb_descriptor_header *) &mdlm_header_desc,
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(struct usb_descriptor_header *) &mdlm_desc,
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(struct usb_descriptor_header *) &mdlm_detail_desc,
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(struct usb_descriptor_header *) ðer_desc,
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(struct usb_descriptor_header *) &fs_subset_in_desc,
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(struct usb_descriptor_header *) &fs_subset_out_desc,
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NULL,
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};
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/* high speed support: */
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static struct usb_endpoint_descriptor hs_subset_in_desc = {
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.bLength = USB_DT_ENDPOINT_SIZE,
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.bDescriptorType = USB_DT_ENDPOINT,
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.bmAttributes = USB_ENDPOINT_XFER_BULK,
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.wMaxPacketSize = cpu_to_le16(512),
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};
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static struct usb_endpoint_descriptor hs_subset_out_desc = {
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.bLength = USB_DT_ENDPOINT_SIZE,
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.bDescriptorType = USB_DT_ENDPOINT,
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.bmAttributes = USB_ENDPOINT_XFER_BULK,
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.wMaxPacketSize = cpu_to_le16(512),
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};
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static struct usb_descriptor_header *hs_eth_function[] = {
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(struct usb_descriptor_header *) &subset_data_intf,
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(struct usb_descriptor_header *) &mdlm_header_desc,
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(struct usb_descriptor_header *) &mdlm_desc,
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(struct usb_descriptor_header *) &mdlm_detail_desc,
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(struct usb_descriptor_header *) ðer_desc,
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(struct usb_descriptor_header *) &hs_subset_in_desc,
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(struct usb_descriptor_header *) &hs_subset_out_desc,
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NULL,
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};
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/* super speed support: */
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static struct usb_endpoint_descriptor ss_subset_in_desc = {
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.bLength = USB_DT_ENDPOINT_SIZE,
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.bDescriptorType = USB_DT_ENDPOINT,
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.bmAttributes = USB_ENDPOINT_XFER_BULK,
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.wMaxPacketSize = cpu_to_le16(1024),
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};
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static struct usb_endpoint_descriptor ss_subset_out_desc = {
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.bLength = USB_DT_ENDPOINT_SIZE,
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.bDescriptorType = USB_DT_ENDPOINT,
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.bmAttributes = USB_ENDPOINT_XFER_BULK,
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.wMaxPacketSize = cpu_to_le16(1024),
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};
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static struct usb_ss_ep_comp_descriptor ss_subset_bulk_comp_desc = {
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.bLength = sizeof ss_subset_bulk_comp_desc,
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.bDescriptorType = USB_DT_SS_ENDPOINT_COMP,
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/* the following 2 values can be tweaked if necessary */
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/* .bMaxBurst = 0, */
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/* .bmAttributes = 0, */
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};
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static struct usb_descriptor_header *ss_eth_function[] = {
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(struct usb_descriptor_header *) &subset_data_intf,
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(struct usb_descriptor_header *) &mdlm_header_desc,
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(struct usb_descriptor_header *) &mdlm_desc,
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(struct usb_descriptor_header *) &mdlm_detail_desc,
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(struct usb_descriptor_header *) ðer_desc,
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(struct usb_descriptor_header *) &ss_subset_in_desc,
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(struct usb_descriptor_header *) &ss_subset_bulk_comp_desc,
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(struct usb_descriptor_header *) &ss_subset_out_desc,
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(struct usb_descriptor_header *) &ss_subset_bulk_comp_desc,
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NULL,
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};
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/* string descriptors: */
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static struct usb_string geth_string_defs[] = {
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[0].s = "CDC Ethernet Subset/SAFE",
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[1].s = "",
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{ } /* end of list */
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};
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static struct usb_gadget_strings geth_string_table = {
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.language = 0x0409, /* en-us */
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.strings = geth_string_defs,
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};
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static struct usb_gadget_strings *geth_strings[] = {
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&geth_string_table,
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NULL,
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};
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/*-------------------------------------------------------------------------*/
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static int geth_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
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{
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struct f_gether *geth = func_to_geth(f);
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struct usb_composite_dev *cdev = f->config->cdev;
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struct net_device *net;
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/* we know alt == 0, so this is an activation or a reset */
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if (geth->port.in_ep->enabled) {
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DBG(cdev, "reset cdc subset\n");
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gether_disconnect(&geth->port);
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}
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DBG(cdev, "init + activate cdc subset\n");
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if (config_ep_by_speed(cdev->gadget, f, geth->port.in_ep) ||
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config_ep_by_speed(cdev->gadget, f, geth->port.out_ep)) {
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geth->port.in_ep->desc = NULL;
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geth->port.out_ep->desc = NULL;
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return -EINVAL;
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}
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net = gether_connect(&geth->port);
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return PTR_ERR_OR_ZERO(net);
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}
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static void geth_disable(struct usb_function *f)
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{
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struct f_gether *geth = func_to_geth(f);
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struct usb_composite_dev *cdev = f->config->cdev;
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DBG(cdev, "net deactivated\n");
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gether_disconnect(&geth->port);
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}
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/*-------------------------------------------------------------------------*/
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/* serial function driver setup/binding */
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static int
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geth_bind(struct usb_configuration *c, struct usb_function *f)
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{
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struct usb_composite_dev *cdev = c->cdev;
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struct f_gether *geth = func_to_geth(f);
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struct usb_string *us;
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int status;
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struct usb_ep *ep;
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struct f_gether_opts *gether_opts;
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gether_opts = container_of(f->fi, struct f_gether_opts, func_inst);
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/*
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* in drivers/usb/gadget/configfs.c:configfs_composite_bind()
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* configurations are bound in sequence with list_for_each_entry,
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* in each configuration its functions are bound in sequence
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* with list_for_each_entry, so we assume no race condition
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* with regard to gether_opts->bound access
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*/
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if (!gether_opts->bound) {
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mutex_lock(&gether_opts->lock);
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gether_set_gadget(gether_opts->net, cdev->gadget);
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status = gether_register_netdev(gether_opts->net);
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mutex_unlock(&gether_opts->lock);
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if (status)
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return status;
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gether_opts->bound = true;
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}
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us = usb_gstrings_attach(cdev, geth_strings,
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ARRAY_SIZE(geth_string_defs));
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if (IS_ERR(us))
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return PTR_ERR(us);
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subset_data_intf.iInterface = us[0].id;
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ether_desc.iMACAddress = us[1].id;
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/* allocate instance-specific interface IDs */
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status = usb_interface_id(c, f);
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if (status < 0)
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goto fail;
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subset_data_intf.bInterfaceNumber = status;
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status = -ENODEV;
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/* allocate instance-specific endpoints */
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ep = usb_ep_autoconfig(cdev->gadget, &fs_subset_in_desc);
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if (!ep)
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goto fail;
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geth->port.in_ep = ep;
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ep = usb_ep_autoconfig(cdev->gadget, &fs_subset_out_desc);
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if (!ep)
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goto fail;
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geth->port.out_ep = ep;
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/* support all relevant hardware speeds... we expect that when
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* hardware is dual speed, all bulk-capable endpoints work at
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* both speeds
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*/
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hs_subset_in_desc.bEndpointAddress = fs_subset_in_desc.bEndpointAddress;
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hs_subset_out_desc.bEndpointAddress =
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fs_subset_out_desc.bEndpointAddress;
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ss_subset_in_desc.bEndpointAddress = fs_subset_in_desc.bEndpointAddress;
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ss_subset_out_desc.bEndpointAddress =
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fs_subset_out_desc.bEndpointAddress;
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status = usb_assign_descriptors(f, fs_eth_function, hs_eth_function,
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ss_eth_function, ss_eth_function);
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if (status)
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goto fail;
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/* NOTE: all that is done without knowing or caring about
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* the network link ... which is unavailable to this code
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* until we're activated via set_alt().
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*/
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DBG(cdev, "CDC Subset: %s speed IN/%s OUT/%s\n",
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gadget_is_superspeed(c->cdev->gadget) ? "super" :
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gadget_is_dualspeed(c->cdev->gadget) ? "dual" : "full",
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geth->port.in_ep->name, geth->port.out_ep->name);
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return 0;
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fail:
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ERROR(cdev, "%s: can't bind, err %d\n", f->name, status);
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return status;
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}
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static inline struct f_gether_opts *to_f_gether_opts(struct config_item *item)
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{
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return container_of(to_config_group(item), struct f_gether_opts,
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func_inst.group);
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}
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/* f_gether_item_ops */
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USB_ETHERNET_CONFIGFS_ITEM(gether);
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/* f_gether_opts_dev_addr */
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USB_ETHERNET_CONFIGFS_ITEM_ATTR_DEV_ADDR(gether);
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/* f_gether_opts_host_addr */
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USB_ETHERNET_CONFIGFS_ITEM_ATTR_HOST_ADDR(gether);
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/* f_gether_opts_qmult */
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USB_ETHERNET_CONFIGFS_ITEM_ATTR_QMULT(gether);
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/* f_gether_opts_ifname */
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USB_ETHERNET_CONFIGFS_ITEM_ATTR_IFNAME(gether);
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static struct configfs_attribute *gether_attrs[] = {
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&gether_opts_attr_dev_addr,
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&gether_opts_attr_host_addr,
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&gether_opts_attr_qmult,
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&gether_opts_attr_ifname,
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NULL,
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};
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static const struct config_item_type gether_func_type = {
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.ct_item_ops = &gether_item_ops,
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.ct_attrs = gether_attrs,
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.ct_owner = THIS_MODULE,
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};
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static void geth_free_inst(struct usb_function_instance *f)
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{
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struct f_gether_opts *opts;
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opts = container_of(f, struct f_gether_opts, func_inst);
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if (opts->bound)
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gether_cleanup(netdev_priv(opts->net));
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else
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free_netdev(opts->net);
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kfree(opts);
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}
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static struct usb_function_instance *geth_alloc_inst(void)
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{
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struct f_gether_opts *opts;
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opts = kzalloc(sizeof(*opts), GFP_KERNEL);
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if (!opts)
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return ERR_PTR(-ENOMEM);
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mutex_init(&opts->lock);
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opts->func_inst.free_func_inst = geth_free_inst;
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opts->net = gether_setup_default();
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if (IS_ERR(opts->net)) {
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struct net_device *net = opts->net;
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kfree(opts);
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return ERR_CAST(net);
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}
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config_group_init_type_name(&opts->func_inst.group, "",
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&gether_func_type);
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return &opts->func_inst;
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}
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static void geth_free(struct usb_function *f)
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{
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struct f_gether *eth;
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eth = func_to_geth(f);
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kfree(eth);
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}
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static void geth_unbind(struct usb_configuration *c, struct usb_function *f)
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{
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geth_string_defs[0].id = 0;
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usb_free_all_descriptors(f);
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}
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static struct usb_function *geth_alloc(struct usb_function_instance *fi)
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{
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struct f_gether *geth;
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struct f_gether_opts *opts;
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int status;
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/* allocate and initialize one new instance */
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geth = kzalloc(sizeof(*geth), GFP_KERNEL);
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if (!geth)
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return ERR_PTR(-ENOMEM);
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opts = container_of(fi, struct f_gether_opts, func_inst);
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mutex_lock(&opts->lock);
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opts->refcnt++;
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/* export host's Ethernet address in CDC format */
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status = gether_get_host_addr_cdc(opts->net, geth->ethaddr,
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sizeof(geth->ethaddr));
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if (status < 12) {
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kfree(geth);
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mutex_unlock(&opts->lock);
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return ERR_PTR(-EINVAL);
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}
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geth_string_defs[1].s = geth->ethaddr;
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geth->port.ioport = netdev_priv(opts->net);
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mutex_unlock(&opts->lock);
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geth->port.cdc_filter = DEFAULT_FILTER;
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geth->port.func.name = "cdc_subset";
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geth->port.func.bind = geth_bind;
|
|
geth->port.func.unbind = geth_unbind;
|
|
geth->port.func.set_alt = geth_set_alt;
|
|
geth->port.func.disable = geth_disable;
|
|
geth->port.func.free_func = geth_free;
|
|
|
|
return &geth->port.func;
|
|
}
|
|
|
|
DECLARE_USB_FUNCTION_INIT(geth, geth_alloc_inst, geth_alloc);
|
|
MODULE_LICENSE("GPL");
|
|
MODULE_AUTHOR("David Brownell");
|