1 | // SPDX-License-Identifier: GPL-2.0-or-later |
2 | /* |
3 | * GeneSys GL620USB-A based links |
4 | * Copyright (C) 2001 by Jiun-Jie Huang <huangjj@genesyslogic.com.tw> |
5 | * Copyright (C) 2001 by Stanislav Brabec <utx@penguin.cz> |
6 | */ |
7 | |
8 | // #define DEBUG // error path messages, extra info |
9 | // #define VERBOSE // more; success messages |
10 | |
11 | #include <linux/module.h> |
12 | #include <linux/netdevice.h> |
13 | #include <linux/etherdevice.h> |
14 | #include <linux/ethtool.h> |
15 | #include <linux/workqueue.h> |
16 | #include <linux/mii.h> |
17 | #include <linux/usb.h> |
18 | #include <linux/usb/usbnet.h> |
19 | #include <linux/gfp.h> |
20 | |
21 | |
22 | /* |
23 | * GeneSys GL620USB-A (www.genesyslogic.com.tw) |
24 | * |
25 | * ... should partially interop with the Win32 driver for this hardware. |
26 | * The GeneSys docs imply there's some NDIS issue motivating this framing. |
27 | * |
28 | * Some info from GeneSys: |
29 | * - GL620USB-A is full duplex; GL620USB is only half duplex for bulk. |
30 | * (Some cables, like the BAFO-100c, use the half duplex version.) |
31 | * - For the full duplex model, the low bit of the version code says |
32 | * which side is which ("left/right"). |
33 | * - For the half duplex type, a control/interrupt handshake settles |
34 | * the transfer direction. (That's disabled here, partially coded.) |
35 | * A control URB would block until other side writes an interrupt. |
36 | * |
37 | * Original code from Jiun-Jie Huang <huangjj@genesyslogic.com.tw> |
38 | * and merged into "usbnet" by Stanislav Brabec <utx@penguin.cz>. |
39 | */ |
40 | |
41 | // control msg write command |
42 | #define GENELINK_CONNECT_WRITE 0xF0 |
43 | // interrupt pipe index |
44 | #define GENELINK_INTERRUPT_PIPE 0x03 |
45 | // interrupt read buffer size |
46 | #define INTERRUPT_BUFSIZE 0x08 |
47 | // interrupt pipe interval value |
48 | #define GENELINK_INTERRUPT_INTERVAL 0x10 |
49 | // max transmit packet number per transmit |
50 | #define GL_MAX_TRANSMIT_PACKETS 32 |
51 | // max packet length |
52 | #define GL_MAX_PACKET_LEN 1514 |
53 | // max receive buffer size |
54 | #define GL_RCV_BUF_SIZE \ |
55 | (((GL_MAX_PACKET_LEN + 4) * GL_MAX_TRANSMIT_PACKETS) + 4) |
56 | |
57 | struct gl_packet { |
58 | __le32 packet_length; |
59 | char packet_data[]; |
60 | }; |
61 | |
62 | struct { |
63 | __le32 ; |
64 | struct gl_packet ; |
65 | }; |
66 | |
67 | static int genelink_rx_fixup(struct usbnet *dev, struct sk_buff *skb) |
68 | { |
69 | struct gl_header *; |
70 | struct gl_packet *packet; |
71 | struct sk_buff *gl_skb; |
72 | u32 size; |
73 | u32 count; |
74 | |
75 | /* This check is no longer done by usbnet */ |
76 | if (skb->len < dev->net->hard_header_len) |
77 | return 0; |
78 | |
79 | header = (struct gl_header *) skb->data; |
80 | |
81 | // get the packet count of the received skb |
82 | count = le32_to_cpu(header->packet_count); |
83 | if (count > GL_MAX_TRANSMIT_PACKETS) { |
84 | netdev_dbg(dev->net, |
85 | "genelink: invalid received packet count %u\n" , |
86 | count); |
87 | return 0; |
88 | } |
89 | |
90 | // set the current packet pointer to the first packet |
91 | packet = &header->packets; |
92 | |
93 | // decrement the length for the packet count size 4 bytes |
94 | skb_pull(skb, len: 4); |
95 | |
96 | while (count > 1) { |
97 | // get the packet length |
98 | size = le32_to_cpu(packet->packet_length); |
99 | |
100 | // this may be a broken packet |
101 | if (size > GL_MAX_PACKET_LEN) { |
102 | netdev_dbg(dev->net, "genelink: invalid rx length %d\n" , |
103 | size); |
104 | return 0; |
105 | } |
106 | |
107 | // allocate the skb for the individual packet |
108 | gl_skb = alloc_skb(size, GFP_ATOMIC); |
109 | if (gl_skb) { |
110 | |
111 | // copy the packet data to the new skb |
112 | skb_put_data(skb: gl_skb, data: packet->packet_data, len: size); |
113 | usbnet_skb_return(dev, gl_skb); |
114 | } |
115 | |
116 | // advance to the next packet |
117 | packet = (struct gl_packet *)&packet->packet_data[size]; |
118 | count--; |
119 | |
120 | // shift the data pointer to the next gl_packet |
121 | skb_pull(skb, len: size + 4); |
122 | } |
123 | |
124 | // skip the packet length field 4 bytes |
125 | skb_pull(skb, len: 4); |
126 | |
127 | if (skb->len > GL_MAX_PACKET_LEN) { |
128 | netdev_dbg(dev->net, "genelink: invalid rx length %d\n" , |
129 | skb->len); |
130 | return 0; |
131 | } |
132 | return 1; |
133 | } |
134 | |
135 | static struct sk_buff * |
136 | genelink_tx_fixup(struct usbnet *dev, struct sk_buff *skb, gfp_t flags) |
137 | { |
138 | int padlen; |
139 | int length = skb->len; |
140 | int headroom = skb_headroom(skb); |
141 | int tailroom = skb_tailroom(skb); |
142 | __le32 *packet_count; |
143 | __le32 *packet_len; |
144 | |
145 | // FIXME: magic numbers, bleech |
146 | padlen = ((skb->len + (4 + 4*1)) % 64) ? 0 : 1; |
147 | |
148 | if ((!skb_cloned(skb)) |
149 | && ((headroom + tailroom) >= (padlen + (4 + 4*1)))) { |
150 | if ((headroom < (4 + 4*1)) || (tailroom < padlen)) { |
151 | skb->data = memmove(skb->head + (4 + 4*1), |
152 | skb->data, skb->len); |
153 | skb_set_tail_pointer(skb, offset: skb->len); |
154 | } |
155 | } else { |
156 | struct sk_buff *skb2; |
157 | skb2 = skb_copy_expand(skb, newheadroom: (4 + 4*1) , newtailroom: padlen, priority: flags); |
158 | dev_kfree_skb_any(skb); |
159 | skb = skb2; |
160 | if (!skb) |
161 | return NULL; |
162 | } |
163 | |
164 | // attach the packet count to the header |
165 | packet_count = skb_push(skb, len: (4 + 4 * 1)); |
166 | packet_len = packet_count + 1; |
167 | |
168 | *packet_count = cpu_to_le32(1); |
169 | *packet_len = cpu_to_le32(length); |
170 | |
171 | // add padding byte |
172 | if ((skb->len % dev->maxpacket) == 0) |
173 | skb_put(skb, len: 1); |
174 | |
175 | return skb; |
176 | } |
177 | |
178 | static int genelink_bind(struct usbnet *dev, struct usb_interface *intf) |
179 | { |
180 | dev->hard_mtu = GL_RCV_BUF_SIZE; |
181 | dev->net->hard_header_len += 4; |
182 | dev->in = usb_rcvbulkpipe(dev->udev, dev->driver_info->in); |
183 | dev->out = usb_sndbulkpipe(dev->udev, dev->driver_info->out); |
184 | return 0; |
185 | } |
186 | |
187 | static const struct driver_info genelink_info = { |
188 | .description = "Genesys GeneLink" , |
189 | .flags = FLAG_POINTTOPOINT | FLAG_FRAMING_GL | FLAG_NO_SETINT, |
190 | .bind = genelink_bind, |
191 | .rx_fixup = genelink_rx_fixup, |
192 | .tx_fixup = genelink_tx_fixup, |
193 | |
194 | .in = 1, .out = 2, |
195 | |
196 | #ifdef GENELINK_ACK |
197 | .check_connect =genelink_check_connect, |
198 | #endif |
199 | }; |
200 | |
201 | static const struct usb_device_id products [] = { |
202 | |
203 | { |
204 | USB_DEVICE(0x05e3, 0x0502), // GL620USB-A |
205 | .driver_info = (unsigned long) &genelink_info, |
206 | }, |
207 | /* NOT: USB_DEVICE(0x05e3, 0x0501), // GL620USB |
208 | * that's half duplex, not currently supported |
209 | */ |
210 | { }, // END |
211 | }; |
212 | MODULE_DEVICE_TABLE(usb, products); |
213 | |
214 | static struct usb_driver gl620a_driver = { |
215 | .name = "gl620a" , |
216 | .id_table = products, |
217 | .probe = usbnet_probe, |
218 | .disconnect = usbnet_disconnect, |
219 | .suspend = usbnet_suspend, |
220 | .resume = usbnet_resume, |
221 | .disable_hub_initiated_lpm = 1, |
222 | }; |
223 | |
224 | module_usb_driver(gl620a_driver); |
225 | |
226 | MODULE_AUTHOR("Jiun-Jie Huang" ); |
227 | MODULE_DESCRIPTION("GL620-USB-A Host-to-Host Link cables" ); |
228 | MODULE_LICENSE("GPL" ); |
229 | |
230 | |