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