1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * CAIF USB handler 4 * Copyright (C) ST-Ericsson AB 2011 5 * Author: Sjur Brendeland 6 */ 7 8 #define pr_fmt(fmt) KBUILD_MODNAME ":%s(): " fmt, __func__ 9 10 #include <linux/module.h> 11 #include <linux/netdevice.h> 12 #include <linux/slab.h> 13 #include <linux/mii.h> 14 #include <linux/usb.h> 15 #include <linux/usb/usbnet.h> 16 #include <linux/etherdevice.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 too 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, const 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 return NULL; 91 92 caif_assert(offsetof(struct cfusbl, layer) == 0); 93 94 memset(&this->layer, 0, sizeof(this->layer)); 95 this->layer.receive = cfusbl_receive; 96 this->layer.transmit = cfusbl_transmit; 97 this->layer.ctrlcmd = cfusbl_ctrlcmd; 98 snprintf(this->layer.name, CAIF_LAYER_NAME_SZ, "usb%d", phyid); 99 this->layer.id = phyid; 100 101 /* 102 * Construct TX ethernet header: 103 * 0-5 destination address 104 * 5-11 source address 105 * 12-13 protocol type 106 */ 107 ether_addr_copy(&this->tx_eth_hdr[ETH_ALEN], braddr); 108 ether_addr_copy(&this->tx_eth_hdr[ETH_ALEN], ethaddr); 109 this->tx_eth_hdr[12] = cpu_to_be16(ETH_P_802_EX1) & 0xff; 110 this->tx_eth_hdr[13] = (cpu_to_be16(ETH_P_802_EX1) >> 8) & 0xff; 111 pr_debug("caif ethernet TX-header dst:%pM src:%pM type:%02x%02x\n", 112 this->tx_eth_hdr, this->tx_eth_hdr + ETH_ALEN, 113 this->tx_eth_hdr[12], this->tx_eth_hdr[13]); 114 115 return (struct cflayer *) this; 116 } 117 118 static void cfusbl_release(struct cflayer *layer) 119 { 120 kfree(layer); 121 } 122 123 static struct packet_type caif_usb_type __read_mostly = { 124 .type = cpu_to_be16(ETH_P_802_EX1), 125 }; 126 127 static int cfusbl_device_notify(struct notifier_block *me, unsigned long what, 128 void *ptr) 129 { 130 struct net_device *dev = netdev_notifier_info_to_dev(ptr); 131 struct caif_dev_common common; 132 struct cflayer *layer, *link_support; 133 struct usbnet *usbnet; 134 struct usb_device *usbdev; 135 int res; 136 137 /* Check whether we have a NCM device, and find its VID/PID. */ 138 if (!(dev->dev.parent && dev->dev.parent->driver && 139 strcmp(dev->dev.parent->driver->name, "cdc_ncm") == 0)) 140 return 0; 141 142 usbnet = netdev_priv(dev); 143 usbdev = usbnet->udev; 144 145 pr_debug("USB CDC NCM device VID:0x%4x PID:0x%4x\n", 146 le16_to_cpu(usbdev->descriptor.idVendor), 147 le16_to_cpu(usbdev->descriptor.idProduct)); 148 149 /* Check for VID/PID that supports CAIF */ 150 if (!(le16_to_cpu(usbdev->descriptor.idVendor) == STE_USB_VID && 151 le16_to_cpu(usbdev->descriptor.idProduct) == STE_USB_PID_CAIF)) 152 return 0; 153 154 if (what == NETDEV_UNREGISTER) 155 module_put(THIS_MODULE); 156 157 if (what != NETDEV_REGISTER) 158 return 0; 159 160 __module_get(THIS_MODULE); 161 162 memset(&common, 0, sizeof(common)); 163 common.use_frag = false; 164 common.use_fcs = false; 165 common.use_stx = false; 166 common.link_select = CAIF_LINK_HIGH_BANDW; 167 common.flowctrl = NULL; 168 169 link_support = cfusbl_create(dev->ifindex, dev->dev_addr, 170 dev->broadcast); 171 172 if (!link_support) 173 return -ENOMEM; 174 175 if (dev->num_tx_queues > 1) 176 pr_warn("USB device uses more than one tx queue\n"); 177 178 res = caif_enroll_dev(dev, &common, link_support, CFUSB_MAX_HEADLEN, 179 &layer, &caif_usb_type.func); 180 if (res) 181 goto err; 182 183 if (!pack_added) 184 dev_add_pack(&caif_usb_type); 185 pack_added = true; 186 187 strscpy(layer->name, dev->name, sizeof(layer->name)); 188 189 return 0; 190 err: 191 cfusbl_release(link_support); 192 return res; 193 } 194 195 static struct notifier_block caif_device_notifier = { 196 .notifier_call = cfusbl_device_notify, 197 .priority = 0, 198 }; 199 200 static int __init cfusbl_init(void) 201 { 202 return register_netdevice_notifier(&caif_device_notifier); 203 } 204 205 static void __exit cfusbl_exit(void) 206 { 207 unregister_netdevice_notifier(&caif_device_notifier); 208 dev_remove_pack(&caif_usb_type); 209 } 210 211 module_init(cfusbl_init); 212 module_exit(cfusbl_exit); 213