caif_usb.c

  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 
 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);
204
This page was automatically generated by LXR 0.3.1 (source). • Linux is a registered trademark of Linus Torvalds
Linux Cross Reference

Free Electrons

Embedded Linux Experts

Linux/net/caif/caif_usb.c
