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, data: &hpad, len: 1); |
44 | cfpkt_extr_head(pkt, NULL, len: 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, data: zeros, len: hpad); |
72 | cfpkt_add_head(pkt, data: &hpad, len: 1); |
73 | cfpkt_add_head(pkt, data: usbl->tx_eth_hdr, len: 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(size: 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(buf: this->layer.name, CAIF_LAYER_NAME_SZ, fmt: "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(dst: &this->tx_eth_hdr[ETH_ALEN], src: braddr); |
108 | ether_addr_copy(dst: &this->tx_eth_hdr[ETH_ALEN], src: 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(objp: 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(info: 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 | if (what == NETDEV_UNREGISTER && dev->reg_state >= NETREG_UNREGISTERED) |
138 | return 0; |
139 | |
140 | /* Check whether we have a NCM device, and find its VID/PID. */ |
141 | if (!(dev->dev.parent && dev->dev.parent->driver && |
142 | strcmp(dev->dev.parent->driver->name, "cdc_ncm" ) == 0)) |
143 | return 0; |
144 | |
145 | usbnet = netdev_priv(dev); |
146 | usbdev = usbnet->udev; |
147 | |
148 | pr_debug("USB CDC NCM device VID:0x%4x PID:0x%4x\n" , |
149 | le16_to_cpu(usbdev->descriptor.idVendor), |
150 | le16_to_cpu(usbdev->descriptor.idProduct)); |
151 | |
152 | /* Check for VID/PID that supports CAIF */ |
153 | if (!(le16_to_cpu(usbdev->descriptor.idVendor) == STE_USB_VID && |
154 | le16_to_cpu(usbdev->descriptor.idProduct) == STE_USB_PID_CAIF)) |
155 | return 0; |
156 | |
157 | if (what == NETDEV_UNREGISTER) |
158 | module_put(THIS_MODULE); |
159 | |
160 | if (what != NETDEV_REGISTER) |
161 | return 0; |
162 | |
163 | __module_get(THIS_MODULE); |
164 | |
165 | memset(&common, 0, sizeof(common)); |
166 | common.use_frag = false; |
167 | common.use_fcs = false; |
168 | common.use_stx = false; |
169 | common.link_select = CAIF_LINK_HIGH_BANDW; |
170 | common.flowctrl = NULL; |
171 | |
172 | link_support = cfusbl_create(phyid: dev->ifindex, ethaddr: dev->dev_addr, |
173 | braddr: dev->broadcast); |
174 | |
175 | if (!link_support) |
176 | return -ENOMEM; |
177 | |
178 | if (dev->num_tx_queues > 1) |
179 | pr_warn("USB device uses more than one tx queue\n" ); |
180 | |
181 | res = caif_enroll_dev(dev, caifdev: &common, link_support, CFUSB_MAX_HEADLEN, |
182 | layer: &layer, rcv_func: &caif_usb_type.func); |
183 | if (res) |
184 | goto err; |
185 | |
186 | if (!pack_added) |
187 | dev_add_pack(pt: &caif_usb_type); |
188 | pack_added = true; |
189 | |
190 | strscpy(p: layer->name, q: dev->name, size: sizeof(layer->name)); |
191 | |
192 | return 0; |
193 | err: |
194 | cfusbl_release(layer: link_support); |
195 | return res; |
196 | } |
197 | |
198 | static struct notifier_block caif_device_notifier = { |
199 | .notifier_call = cfusbl_device_notify, |
200 | .priority = 0, |
201 | }; |
202 | |
203 | static int __init cfusbl_init(void) |
204 | { |
205 | return register_netdevice_notifier(nb: &caif_device_notifier); |
206 | } |
207 | |
208 | static void __exit cfusbl_exit(void) |
209 | { |
210 | unregister_netdevice_notifier(nb: &caif_device_notifier); |
211 | dev_remove_pack(pt: &caif_usb_type); |
212 | } |
213 | |
214 | module_init(cfusbl_init); |
215 | module_exit(cfusbl_exit); |
216 | |