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_DESCRIPTION("ST-Ericsson CAIF modem protocol USB support"); 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 too 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, const 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 } 118 119 static void cfusbl_release(struct cflayer *layer) 120 { 121 kfree(layer); 122 } 123 124 static struct packet_type caif_usb_type __read_mostly = { 125 .type = cpu_to_be16(ETH_P_802_EX1), 126 }; 127 128 static int cfusbl_device_notify(struct notifier_block *me, unsigned long what, 129 void *ptr) 130 { 131 struct net_device *dev = netdev_notifier_info_to_dev(ptr); 132 struct caif_dev_common common; 133 struct cflayer *layer, *link_support; 134 struct usbnet *usbnet; 135 struct usb_device *usbdev; 136 int res; 137 138 if (what == NETDEV_UNREGISTER && dev->reg_state >= NETREG_UNREGISTERED) 139 return 0; 140 141 /* Check whether we have a NCM device, and find its VID/PID. */ 142 if (!(dev->dev.parent && dev->dev.parent->driver && 143 strcmp(dev->dev.parent->driver->name, "cdc_ncm") == 0)) 144 return 0; 145 146 usbnet = netdev_priv(dev); 147 usbdev = usbnet->udev; 148 149 pr_debug("USB CDC NCM device VID:0x%4x PID:0x%4x\n", 150 le16_to_cpu(usbdev->descriptor.idVendor), 151 le16_to_cpu(usbdev->descriptor.idProduct)); 152 153 /* Check for VID/PID that supports CAIF */ 154 if (!(le16_to_cpu(usbdev->descriptor.idVendor) == STE_USB_VID && 155 le16_to_cpu(usbdev->descriptor.idProduct) == STE_USB_PID_CAIF)) 156 return 0; 157 158 if (what == NETDEV_UNREGISTER) 159 module_put(THIS_MODULE); 160 161 if (what != NETDEV_REGISTER) 162 return 0; 163 164 __module_get(THIS_MODULE); 165 166 memset(&common, 0, sizeof(common)); 167 common.use_frag = false; 168 common.use_fcs = false; 169 common.use_stx = false; 170 common.link_select = CAIF_LINK_HIGH_BANDW; 171 common.flowctrl = NULL; 172 173 link_support = cfusbl_create(dev->ifindex, dev->dev_addr, 174 dev->broadcast); 175 176 if (!link_support) 177 return -ENOMEM; 178 179 if (dev->num_tx_queues > 1) 180 pr_warn("USB device uses more than one tx queue\n"); 181 182 res = caif_enroll_dev(dev, &common, link_support, CFUSB_MAX_HEADLEN, 183 &layer, &caif_usb_type.func); 184 if (res) 185 goto err; 186 187 if (!pack_added) 188 dev_add_pack(&caif_usb_type); 189 pack_added = true; 190 191 strscpy(layer->name, dev->name, sizeof(layer->name)); 192 193 return 0; 194 err: 195 cfusbl_release(link_support); 196 return res; 197 } 198 199 static struct notifier_block caif_device_notifier = { 200 .notifier_call = cfusbl_device_notify, 201 .priority = 0, 202 }; 203 204 static int __init cfusbl_init(void) 205 { 206 return register_netdevice_notifier(&caif_device_notifier); 207 } 208 209 static void __exit cfusbl_exit(void) 210 { 211 unregister_netdevice_notifier(&caif_device_notifier); 212 dev_remove_pack(&caif_usb_type); 213 } 214 215 module_init(cfusbl_init); 216 module_exit(cfusbl_exit); 217