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
cfusbl_receive(struct cflayer * layr,struct cfpkt * pkt)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
cfusbl_transmit(struct cflayer * layr,struct cfpkt * pkt)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
cfusbl_ctrlcmd(struct cflayer * layr,enum caif_ctrlcmd ctrl,int phyid)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
cfusbl_create(int phyid,u8 ethaddr[ETH_ALEN],u8 braddr[ETH_ALEN])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 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
cfusbl_release(struct cflayer * layer)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
cfusbl_device_notify(struct notifier_block * me,unsigned long what,void * ptr)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 strlcpy(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
cfusbl_init(void)200 static int __init cfusbl_init(void)
201 {
202 return register_netdevice_notifier(&caif_device_notifier);
203 }
204
cfusbl_exit(void)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
