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