/*
* f_ncm.c -- USB CDC Network (NCM) link function driver
*
* Copyright (C) 2010 Nokia Corporation
* Contact: Yauheni Kaliuta <yauheni.kaliuta@nokia.com>
*
* The driver borrows from f_ecm.c which is:
*
* Copyright (C) 2003-2005,2008 David Brownell
* Copyright (C) 2008 Nokia Corporation
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*/
#include <linux/kernel.h>
#include <linux/device.h>
#include <linux/etherdevice.h>
#include <linux/crc32.h>
#include <linux/usb/cdc.h>
#include "u_ether.h"
/*
* This function is a "CDC Network Control Model" (CDC NCM) Ethernet link.
* NCM is intended to be used with high-speed network attachments.
*
* Note that NCM 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.
*/
/* to trigger crc/non-crc ndp signature */
#define NCM_NDP_HDR_CRC_MASK 0x01000000
#define NCM_NDP_HDR_CRC 0x01000000
#define NCM_NDP_HDR_NOCRC 0x00000000
enum ncm_notify_state {
NCM_NOTIFY_NONE, /* don't notify */
NCM_NOTIFY_CONNECT, /* issue CONNECT next */
NCM_NOTIFY_SPEED, /* issue SPEED_CHANGE next */
};
struct f_ncm {
struct gether port;
u8 ctrl_id, data_id;
char ethaddr[14];
struct usb_ep *notify;
struct usb_request *notify_req;
u8 notify_state;
bool is_open;
const struct ndp_parser_opts *parser_opts;
bool is_crc;
u32 ndp_sign;
/*
* for notification, it is accessed from both
* callback and ethernet open/close
*/
spinlock_t lock;
};
static inline struct f_ncm *func_to_ncm(struct usb_function *f)
{
return container_of(f, struct f_ncm, port.func);
}
/* peak (theoretical) bulk transfer rate in bits-per-second */
static inline unsigned ncm_bitrate(struct usb_gadget *g)
{
if (gadget_is_dualspeed(g) && g->speed == USB_SPEED_HIGH)
return 13 * 512 * 8 * 1000 * 8;
else
return 19 * 64 * 1 * 1000 * 8;
}
/*-------------------------------------------------------------------------*/
/*
* We cannot group frames so use just the minimal size which ok to put
* one max-size ethernet frame.
* If the host can group frames, allow it to do that, 16K is selected,
* because it's used by default by the current linux host driver
*/
#define NTB_DEFAULT_IN_SIZE USB_CDC_NCM_NTB_MIN_IN_SIZE
#define NTB_OUT_SIZE 16384
/*
* skbs of size less than that will not be aligned
* to NCM's dwNtbInMaxSize to save bus bandwidth
*/
#define MAX_TX_NONFIXED (512 * 3)
#define FORMATS_SUPPORTED (USB_CDC_NCM_NTB16_SUPPORTED | \
USB_CDC_NCM_NTB32_SUPPORTED)
static struct usb_cdc_ncm_ntb_parameters ntb_parameters = {
.wLength = cpu_to_le16(sizeof(ntb_parameters)),
.bmNtbFormatsSupported = cpu_to_le16(FORMATS_SUPPORTED),
.dwNtbInMaxSize = cpu_to_le32(NTB_DEFAULT_IN_SIZE),
.wNdpInDivisor = cpu_to_le16(4),
.wNdpInPayloadRemainder = cpu_to_le16(0),
.wNdpInAlignment = cpu_to_le16(4),
.dwNtbOutMaxSize = cpu_to_le32(NTB_OUT_SIZE),
.wNdpOutDivisor = cpu_to_le16(4),
.wNdpOutPayloadRemainder = cpu_to_le16(0),
.wNdpOutAlignment = cpu_to_le16(4),
};
/*
* 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.
*/
#define NCM_STATUS_INTERVAL_MS 32
#define NCM_STATUS_BYTECOUNT 16 /* 8 byte header + data */
static struct usb_interface_assoc_descriptor ncm_iad_desc = {
.bLength = sizeof ncm_iad_desc,
.bDescriptorType = USB_DT_INTERFACE_ASSOCIATION,
/* .bFirstInterface = DYNAMIC, */
.bInterfaceCount = 2, /* control + data */
.bFunctionClass = USB_CLASS_COMM,
.bFunctionSubClass = USB_CDC_SUBCLASS_NCM,
.bFunctionProtocol = USB_CDC_PROTO_NONE,
/* .iFunction = DYNAMIC */
};
/* interface descriptor: */
static struct usb_interface_descriptor ncm_control_intf = {
.bLength = sizeof ncm_control_intf,
.bDescriptorType = USB_DT_INTERFACE,
/* .bInterfaceNumber = DYNAMIC */
.bNumEndpoints = 1,
.bInterfaceClass = USB_CLASS_COMM,
.bInterfaceSubClass = USB_CDC_SUBCLASS_NCM,
.bInterfaceProtocol = USB_CDC_PROTO_NONE,
/* .iInterface = DYNAMIC */
};
static struct usb_cdc_header_desc ncm_header_desc = {
.bLength = sizeof ncm_header_desc,
.bDescriptorType = USB_DT_CS_INTERFACE,
.bDescriptorSubType = USB_CDC_HEADER_TYPE,
.bcdCDC = cpu_to_le16(0x0110),
};
static struct usb_cdc_union_desc ncm_union_desc = {
.bLength = sizeof(ncm_union_desc),
.bDescriptorType = USB_DT_CS_INTERFACE,
.bDescriptorSubType = USB_CDC_UNION_TYPE,
/* .bMasterInterface0 = DYNAMIC */
/* .bSlaveInterface0 = DYNAMIC */
};
static struct usb_cdc_ether_desc ecm_desc = {
.bLength = sizeof ecm_desc,
.bDescriptorType = USB_DT_CS_INTERFACE,
.bDescriptorSubType = USB_CDC_ETHERNET_TYPE,
/* this descriptor actually adds value, surprise! */
/* .iMACAddress = DYNAMIC */
.bmEthernetStatistics = cpu_to_le32(0), /* no statistics */
.wMaxSegmentSize = cpu_to_le16(ETH_FRAME_LEN),
.wNumberMCFilters = cpu_to_le16(0),
.bNumberPowerFilters = 0,
};
#define NCAPS (USB_CDC_NCM_NCAP_ETH_FILTER | USB_CDC_NCM_NCAP_CRC_MODE)
static struct usb_cdc_ncm_desc ncm_desc = {
.bLength = sizeof ncm_desc,
.bDescriptorType = USB_DT_CS_INTERFACE,
.bDescriptorSubType = USB_CDC_NCM_TYPE,
.bcdNcmVersion = cpu_to_le16(0x0100),
/* can process SetEthernetPacketFilter */
.bmNetworkCapabilities = NCAPS,
};
/* the default data interface has no endpoints ... */
static struct usb_interface_descriptor ncm_data_nop_intf = {
.bLength = sizeof ncm_data_nop_intf,
.bDescriptorType = USB_DT_INTERFACE,
.bInterfaceNumber = 1,
.bAlternateSetting = 0,
.bNumEndpoints = 0,
.bInterfaceClass = USB_CLASS_CDC_DATA,
.bInterfaceSubClass = 0,
.bInterfaceProtocol = USB_CDC_NCM_PROTO_NTB,
/* .iInterface = DYNAMIC */
};
/* ... but the "real" data interface has two bulk endpoints */