xref: /linux/net/caif/caif_usb.c (revision 90ab5ee94171b3e28de6bb42ee30b527014e0be7)
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/netdevice.h>
15 #include <linux/mii.h>
16 #include <linux/usb.h>
17 #include <linux/usb/usbnet.h>
18 #include <net/netns/generic.h>
19 #include <net/caif/caif_dev.h>
20 #include <net/caif/caif_layer.h>
21 #include <net/caif/cfpkt.h>
22 #include <net/caif/cfcnfg.h>
23 
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 0x2306	/* 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 to 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 struct cflayer *cfusbl_create(int phyid, 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 		pr_warn("Out of memory\n");
92 		return NULL;
93 	}
94 	caif_assert(offsetof(struct cfusbl, layer) == 0);
95 
96 	memset(this, 0, sizeof(struct cflayer));
97 	this->layer.receive = cfusbl_receive;
98 	this->layer.transmit = cfusbl_transmit;
99 	this->layer.ctrlcmd = cfusbl_ctrlcmd;
100 	snprintf(this->layer.name, CAIF_LAYER_NAME_SZ, "usb%d", phyid);
101 	this->layer.id = phyid;
102 
103 	/*
104 	 * Construct TX ethernet header:
105 	 *	0-5	destination address
106 	 *	5-11	source address
107 	 *	12-13	protocol type
108 	 */
109 	memcpy(&this->tx_eth_hdr[ETH_ALEN], braddr, ETH_ALEN);
110 	memcpy(&this->tx_eth_hdr[ETH_ALEN], ethaddr, ETH_ALEN);
111 	this->tx_eth_hdr[12] = cpu_to_be16(ETH_P_802_EX1) & 0xff;
112 	this->tx_eth_hdr[13] = (cpu_to_be16(ETH_P_802_EX1) >> 8) & 0xff;
113 	pr_debug("caif ethernet TX-header dst:%pM src:%pM type:%02x%02x\n",
114 			this->tx_eth_hdr, this->tx_eth_hdr + ETH_ALEN,
115 			this->tx_eth_hdr[12], this->tx_eth_hdr[13]);
116 
117 	return (struct cflayer *) this;
118 }
119 
120 static struct packet_type caif_usb_type __read_mostly = {
121 	.type = cpu_to_be16(ETH_P_802_EX1),
122 };
123 
124 static int cfusbl_device_notify(struct notifier_block *me, unsigned long what,
125 			      void *arg)
126 {
127 	struct net_device *dev = arg;
128 	struct caif_dev_common common;
129 	struct cflayer *layer, *link_support;
130 	struct usbnet	*usbnet = netdev_priv(dev);
131 	struct usb_device	*usbdev = usbnet->udev;
132 	struct ethtool_drvinfo drvinfo;
133 
134 	/*
135 	 * Quirks: High-jack ethtool to find if we have a NCM device,
136 	 * and find it's VID/PID.
137 	 */
138 	if (dev->ethtool_ops == NULL || dev->ethtool_ops->get_drvinfo == NULL)
139 		return 0;
140 
141 	dev->ethtool_ops->get_drvinfo(dev, &drvinfo);
142 	if (strncmp(drvinfo.driver, "cdc_ncm", 7) != 0)
143 		return 0;
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 	caif_enroll_dev(dev, &common, link_support, CFUSB_MAX_HEADLEN,
179 			&layer, &caif_usb_type.func);
180 	if (!pack_added)
181 		dev_add_pack(&caif_usb_type);
182 	pack_added = true;
183 
184 	strncpy(layer->name, dev->name,
185 			sizeof(layer->name) - 1);
186 	layer->name[sizeof(layer->name) - 1] = 0;
187 
188 	return 0;
189 }
190 
191 static struct notifier_block caif_device_notifier = {
192 	.notifier_call = cfusbl_device_notify,
193 	.priority = 0,
194 };
195 
196 static int __init cfusbl_init(void)
197 {
198 	return register_netdevice_notifier(&caif_device_notifier);
199 }
200 
201 static void __exit cfusbl_exit(void)
202 {
203 	unregister_netdevice_notifier(&caif_device_notifier);
204 	dev_remove_pack(&caif_usb_type);
205 }
206 
207 module_init(cfusbl_init);
208 module_exit(cfusbl_exit);
209