linux/net/caif/caif_usb.c
<<
>>
Prefs
   1/*
   2 * CAIF USB handler
   3 * Copyright (C) ST-Ericsson AB 2011
   4 * Author:      Sjur Brendeland
   5 * License terms: GNU General Public License (GPL) version 2
   6 *
   7 */
   8
   9#define pr_fmt(fmt) KBUILD_MODNAME ":%s(): " fmt, __func__
  10
  11#include <linux/module.h>
  12#include <linux/netdevice.h>
  13#include <linux/slab.h>
  14#include <linux/mii.h>
  15#include <linux/usb.h>
  16#include <linux/usb/usbnet.h>
  17#include <linux/etherdevice.h>
  18#include <net/netns/generic.h>
  19#include <net/caif/caif_dev.h>
  20#include <net/caif/caif_layer.h>
  21#include <net/caif/cfpkt.h>
  22#include <net/caif/cfcnfg.h>
  23
  24MODULE_LICENSE("GPL");
  25
  26#define CFUSB_PAD_DESCR_SZ 1    /* Alignment descriptor length */
  27#define CFUSB_ALIGNMENT 4       /* Number of bytes to align. */
  28#define CFUSB_MAX_HEADLEN (CFUSB_PAD_DESCR_SZ + CFUSB_ALIGNMENT-1)
  29#define STE_USB_VID 0x04cc      /* USB Product ID for ST-Ericsson */
  30#define STE_USB_PID_CAIF 0x230f /* Product id for CAIF Modems */
  31
  32struct cfusbl {
  33        struct cflayer layer;
  34        u8 tx_eth_hdr[ETH_HLEN];
  35};
  36
  37static bool pack_added;
  38
  39static int cfusbl_receive(struct cflayer *layr, struct cfpkt *pkt)
  40{
  41        u8 hpad;
  42
  43        /* Remove padding. */
  44        cfpkt_extr_head(pkt, &hpad, 1);
  45        cfpkt_extr_head(pkt, NULL, hpad);
  46        return layr->up->receive(layr->up, pkt);
  47}
  48
  49static int cfusbl_transmit(struct cflayer *layr, struct cfpkt *pkt)
  50{
  51        struct caif_payload_info *info;
  52        u8 hpad;
  53        u8 zeros[CFUSB_ALIGNMENT];
  54        struct sk_buff *skb;
  55        struct cfusbl *usbl = container_of(layr, struct cfusbl, layer);
  56
  57        skb = cfpkt_tonative(pkt);
  58
  59        skb_reset_network_header(skb);
  60        skb->protocol = htons(ETH_P_IP);
  61
  62        info = cfpkt_info(pkt);
  63        hpad = (info->hdr_len + CFUSB_PAD_DESCR_SZ) & (CFUSB_ALIGNMENT - 1);
  64
  65        if (skb_headroom(skb) < ETH_HLEN + CFUSB_PAD_DESCR_SZ + hpad) {
  66                pr_warn("Headroom to small\n");
  67                kfree_skb(skb);
  68                return -EIO;
  69        }
  70        memset(zeros, 0, hpad);
  71
  72        cfpkt_add_head(pkt, zeros, hpad);
  73        cfpkt_add_head(pkt, &hpad, 1);
  74        cfpkt_add_head(pkt, usbl->tx_eth_hdr, sizeof(usbl->tx_eth_hdr));
  75        return layr->dn->transmit(layr->dn, pkt);
  76}
  77
  78static void cfusbl_ctrlcmd(struct cflayer *layr, enum caif_ctrlcmd ctrl,
  79                           int phyid)
  80{
  81        if (layr->up && layr->up->ctrlcmd)
  82                layr->up->ctrlcmd(layr->up, ctrl, layr->id);
  83}
  84
  85static struct cflayer *cfusbl_create(int phyid, u8 ethaddr[ETH_ALEN],
  86                                      u8 braddr[ETH_ALEN])
  87{
  88        struct cfusbl *this = kmalloc(sizeof(struct cfusbl), GFP_ATOMIC);
  89
  90        if (!this) {
  91                pr_warn("Out of memory\n");
  92                return NULL;
  93        }
  94        caif_assert(offsetof(struct cfusbl, layer) == 0);
  95
  96        memset(this, 0, sizeof(struct cflayer));
  97        this->layer.receive = cfusbl_receive;
  98        this->layer.transmit = cfusbl_transmit;
  99        this->layer.ctrlcmd = cfusbl_ctrlcmd;
 100        snprintf(this->layer.name, CAIF_LAYER_NAME_SZ, "usb%d", phyid);
 101        this->layer.id = phyid;
 102
 103        /*
 104         * Construct TX ethernet header:
 105         *      0-5     destination address
 106         *      5-11    source address
 107         *      12-13   protocol type
 108         */
 109        ether_addr_copy(&this->tx_eth_hdr[ETH_ALEN], braddr);
 110        ether_addr_copy(&this->tx_eth_hdr[ETH_ALEN], ethaddr);
 111        this->tx_eth_hdr[12] = cpu_to_be16(ETH_P_802_EX1) & 0xff;
 112        this->tx_eth_hdr[13] = (cpu_to_be16(ETH_P_802_EX1) >> 8) & 0xff;
 113        pr_debug("caif ethernet TX-header dst:%pM src:%pM type:%02x%02x\n",
 114                        this->tx_eth_hdr, this->tx_eth_hdr + ETH_ALEN,
 115                        this->tx_eth_hdr[12], this->tx_eth_hdr[13]);
 116
 117        return (struct cflayer *) this;
 118}
 119
 120static struct packet_type caif_usb_type __read_mostly = {
 121        .type = cpu_to_be16(ETH_P_802_EX1),
 122};
 123
 124static int cfusbl_device_notify(struct notifier_block *me, unsigned long what,
 125                                void *ptr)
 126{
 127        struct net_device *dev = netdev_notifier_info_to_dev(ptr);
 128        struct caif_dev_common common;
 129        struct cflayer *layer, *link_support;
 130        struct usbnet *usbnet;
 131        struct usb_device *usbdev;
 132
 133        /* Check whether we have a NCM device, and find its VID/PID. */
 134        if (!(dev->dev.parent && dev->dev.parent->driver &&
 135              strcmp(dev->dev.parent->driver->name, "cdc_ncm") == 0))
 136                return 0;
 137
 138        usbnet = netdev_priv(dev);
 139        usbdev = usbnet->udev;
 140
 141        pr_debug("USB CDC NCM device VID:0x%4x PID:0x%4x\n",
 142                le16_to_cpu(usbdev->descriptor.idVendor),
 143                le16_to_cpu(usbdev->descriptor.idProduct));
 144
 145        /* Check for VID/PID that supports CAIF */
 146        if (!(le16_to_cpu(usbdev->descriptor.idVendor) == STE_USB_VID &&
 147                le16_to_cpu(usbdev->descriptor.idProduct) == STE_USB_PID_CAIF))
 148                return 0;
 149
 150        if (what == NETDEV_UNREGISTER)
 151                module_put(THIS_MODULE);
 152
 153        if (what != NETDEV_REGISTER)
 154                return 0;
 155
 156        __module_get(THIS_MODULE);
 157
 158        memset(&common, 0, sizeof(common));
 159        common.use_frag = false;
 160        common.use_fcs = false;
 161        common.use_stx = false;
 162        common.link_select = CAIF_LINK_HIGH_BANDW;
 163        common.flowctrl = NULL;
 164
 165        link_support = cfusbl_create(dev->ifindex, dev->dev_addr,
 166                                        dev->broadcast);
 167
 168        if (!link_support)
 169                return -ENOMEM;
 170
 171        if (dev->num_tx_queues > 1)
 172                pr_warn("USB device uses more than one tx queue\n");
 173
 174        caif_enroll_dev(dev, &common, link_support, CFUSB_MAX_HEADLEN,
 175                        &layer, &caif_usb_type.func);
 176        if (!pack_added)
 177                dev_add_pack(&caif_usb_type);
 178        pack_added = true;
 179
 180        strncpy(layer->name, dev->name,
 181                        sizeof(layer->name) - 1);
 182        layer->name[sizeof(layer->name) - 1] = 0;
 183
 184        return 0;
 185}
 186
 187static struct notifier_block caif_device_notifier = {
 188        .notifier_call = cfusbl_device_notify,
 189        .priority = 0,
 190};
 191
 192static int __init cfusbl_init(void)
 193{
 194        return register_netdevice_notifier(&caif_device_notifier);
 195}
 196
 197static void __exit cfusbl_exit(void)
 198{
 199        unregister_netdevice_notifier(&caif_device_notifier);
 200        dev_remove_pack(&caif_usb_type);
 201}
 202
 203module_init(cfusbl_init);
 204module_exit(cfusbl_exit);
 205