summaryrefslogtreecommitdiffstats
path: root/drivers/net/usb/gl620a.c
blob: 38266bdae26b9ced95c79c19742b3458a55414f2 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
/*
 * GeneSys GL620USB-A based links
 * Copyright (C) 2001 by Jiun-Jie Huang <huangjj@genesyslogic.com.tw>
 * Copyright (C) 2001 by Stanislav Brabec <utx@penguin.cz>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

// #define	DEBUG			// error path messages, extra info
// #define	VERBOSE			// more; success messages

#include <linux/module.h>
#include <linux/init.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/ethtool.h>
#include <linux/workqueue.h>
#include <linux/mii.h>
#include <linux/usb.h>
#include <linux/usb/usbnet.h>
#include <linux/gfp.h>


/*
 * GeneSys GL620USB-A (www.genesyslogic.com.tw)
 *
 * ... should partially interop with the Win32 driver for this hardware.
 * The GeneSys docs imply there's some NDIS issue motivating this framing.
 *
 * Some info from GeneSys:
 *  - GL620USB-A is full duplex; GL620USB is only half duplex for bulk.
 *    (Some cables, like the BAFO-100c, use the half duplex version.)
 *  - For the full duplex model, the low bit of the version code says
 *    which side is which ("left/right").
 *  - For the half duplex type, a control/interrupt handshake settles
 *    the transfer direction.  (That's disabled here, partially coded.)
 *    A control URB would block until other side writes an interrupt.
 *
 * Original code from Jiun-Jie Huang <huangjj@genesyslogic.com.tw>
 * and merged into "usbnet" by Stanislav Brabec <utx@penguin.cz>.
 */

// control msg write command
#define GENELINK_CONNECT_WRITE			0xF0
// interrupt pipe index
#define GENELINK_INTERRUPT_PIPE			0x03
// interrupt read buffer size
#define INTERRUPT_BUFSIZE			0x08
// interrupt pipe interval value
#define GENELINK_INTERRUPT_INTERVAL		0x10
// max transmit packet number per transmit
#define GL_MAX_TRANSMIT_PACKETS			32
// max packet length
#define GL_MAX_PACKET_LEN			1514
// max receive buffer size
#define GL_RCV_BUF_SIZE		\
	(((GL_MAX_PACKET_LEN + 4) * GL_MAX_TRANSMIT_PACKETS) + 4)

struct gl_packet {
	__le32		packet_length;
	char		packet_data [1];
};

struct gl_header {
	__le32			packet_count;
	struct gl_packet	packets;
};

static int genelink_rx_fixup(struct usbnet *dev, struct sk_buff *skb)
{
	struct gl_header	*header;
	struct gl_packet	*packet;
	struct sk_buff		*gl_skb;
	u32			size;
	u32			count;

	header = (struct gl_header *) skb->data;

	// get the packet count of the received skb
	count = le32_to_cpu(header->packet_count);
	if (count > GL_MAX_TRANSMIT_PACKETS) {
		dbg("genelink: invalid received packet count %u", count);
		return 0;
	}

	// set the current packet pointer to the first packet
	packet = &header->packets;

	// decrement the length for the packet count size 4 bytes
	skb_pull(skb, 4);

	while (count > 1) {
		// get the packet length
		size = le32_to_cpu(packet->packet_length);

		// this may be a broken packet
		if (size > GL_MAX_PACKET_LEN) {
			dbg("genelink: invalid rx length %d", size);
			return 0;
		}

		// allocate the skb for the individual packet
		gl_skb = alloc_skb(size, GFP_ATOMIC);
		if (gl_skb) {

			// copy the packet data to the new skb
			memcpy(skb_put(gl_skb, size),
					packet->packet_data, size);
			usbnet_skb_return(dev, gl_skb);
		}

		// advance to the next packet
		packet = (struct gl_packet *)&packet->packet_data[size];
		count--;

		// shift the data pointer to the next gl_packet
		skb_pull(skb, size + 4);
	}

	// skip the packet length field 4 bytes
	skb_pull(skb, 4);

	if (skb->len > GL_MAX_PACKET_LEN) {
		dbg("genelink: invalid rx length %d", skb->len);
		return 0;
	}
	return 1;
}

static struct sk_buff *
genelink_tx_fixup(struct usbnet *dev, struct sk_buff *skb, gfp_t flags)
{
	int 	padlen;
	int	length = skb->len;
	int	headroom = skb_headroom(skb);
	int	tailroom = skb_tailroom(skb);
	__le32	*packet_count;
	__le32	*packet_len;

	// FIXME:  magic numbers, bleech
	padlen = ((skb->len + (4 + 4*1)) % 64) ? 0 : 1;

	if ((!skb_cloned(skb))
			&& ((headroom + tailroom) >= (padlen + (4 + 4*1)))) {
		if ((headroom < (4 + 4*1)) || (tailroom < padlen)) {
			skb->data = memmove(skb->head + (4 + 4*1),
					     skb->data, skb->len);
			skb_set_tail_pointer(skb, skb->len);
		}
	} else {
		struct sk_buff	*skb2;
		skb2 = skb_copy_expand(skb, (4 + 4*1) , padlen, flags);
		dev_kfree_skb_any(skb);
		skb = skb2;
		if (!skb)
			return NULL;
	}

	// attach the packet count to the header
	packet_count = (__le32 *) skb_push(skb, (4 + 4*1));
	packet_len = packet_count + 1;

	*packet_count = cpu_to_le32(1);
	*packet_len = cpu_to_le32(length);

	// add padding byte
	if ((skb->len % dev->maxpacket) == 0)
		skb_put(skb, 1);

	return skb;
}

static int genelink_bind(struct usbnet *dev, struct usb_interface *intf)
{
	dev->hard_mtu = GL_RCV_BUF_SIZE;
	dev->net->hard_header_len += 4;
	dev->in = usb_rcvbulkpipe(dev->udev, dev->driver_info->in);
	dev->out = usb_sndbulkpipe(dev->udev, dev->driver_info->out);
	return 0;
}

static const struct driver_info	genelink_info = {
	.description =	"Genesys GeneLink",
	.flags =	FLAG_POINTTOPOINT | FLAG_FRAMING_GL | FLAG_NO_SETINT,
	.bind =		genelink_bind,
	.rx_fixup =	genelink_rx_fixup,
	.tx_fixup =	genelink_tx_fixup,

	.in = 1, .out = 2,

#ifdef	GENELINK_ACK
	.check_connect =genelink_check_connect,
#endif
};

static const struct usb_device_id	products [] = {

{
	USB_DEVICE(0x05e3, 0x0502),	// GL620USB-A
	.driver_info =	(unsigned long) &genelink_info,
},
	/* NOT: USB_DEVICE(0x05e3, 0x0501),	// GL620USB
	 * that's half duplex, not currently supported
	 */
	{ },		// END
};
MODULE_DEVICE_TABLE(usb, products);

static struct usb_driver gl620a_driver = {
	.name =		"gl620a",
	.id_table =	products,
	.probe =	usbnet_probe,
	.disconnect =	usbnet_disconnect,
	.suspend =	usbnet_suspend,
	.resume =	usbnet_resume,
};

module_usb_driver(gl620a_driver);

MODULE_AUTHOR("Jiun-Jie Huang");
MODULE_DESCRIPTION("GL620-USB-A Host-to-Host Link cables");
MODULE_LICENSE("GPL");

OpenPOWER on IntegriCloud