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
   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                return NULL;
  92
  93        caif_assert(offsetof(struct cfusbl, layer) == 0);
  94
  95        memset(&this->layer, 0, sizeof(this->layer));
  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        ether_addr_copy(&this->tx_eth_hdr[ETH_ALEN], braddr);
 109        ether_addr_copy(&this->tx_eth_hdr[ETH_ALEN], ethaddr);
 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 *ptr)
 125{
 126        struct net_device *dev = netdev_notifier_info_to_dev(ptr);
 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        strlcpy(layer->name, dev->name, sizeof(layer->name));
 180
 181        return 0;
 182}
 183
 184static struct notifier_block caif_device_notifier = {
 185        .notifier_call = cfusbl_device_notify,
 186        .priority = 0,
 187};
 188
 189static int __init cfusbl_init(void)
 190{
 191        return register_netdevice_notifier(&caif_device_notifier);
 192}
 193
 194static void __exit cfusbl_exit(void)
 195{
 196        unregister_netdevice_notifier(&caif_device_notifier);
 197        dev_remove_pack(&caif_usb_type);
 198}
 199
 200module_init(cfusbl_init);
 201module_exit(cfusbl_exit);
 202