net/caif/caif_usb.c

   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
  24 MODULE_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
  32 struct cfusbl {
  33         struct cflayer layer;
  34         u8 tx_eth_hdr[ETH_HLEN];
  35 };
  36
  37 static bool pack_added;
  38
  39 static 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
  49 static 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
  78 static 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
  85 static 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
 120 static struct packet_type caif_usb_type __read_mostly = {
 121         .type = cpu_to_be16(ETH_P_802_EX1),
 122 };
 123
 124 static 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
 187 static struct notifier_block caif_device_notifier = {
 188         .notifier_call = cfusbl_device_notify,
 189         .priority = 0,
 190 };
 191
 192 static int __init cfusbl_init(void)
 193 {
 194         return register_netdevice_notifier(&caif_device_notifier);
 195 }
 196
 197 static void __exit cfusbl_exit(void)
 198 {
 199         unregister_netdevice_notifier(&caif_device_notifier);
 200         dev_remove_pack(&caif_usb_type);
 201 }
 202
 203 module_init(cfusbl_init);
 204 module_exit(cfusbl_exit);