1			  Linux ACM driver v0.16
2		 (c) 1999 Vojtech Pavlik <vojtech@suse.cz>
3			     Sponsored by SuSE
4----------------------------------------------------------------------------
5
60. Disclaimer
7~~~~~~~~~~~~~
8  This program is free software; you can redistribute it and/or modify it
9under the terms of the GNU General Public License as published by the Free
10Software Foundation; either version 2 of the License, or (at your option)
11any later version.
12
13  This program is distributed in the hope that it will be useful, but
14WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
15or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
16more details.
17
18  You should have received a copy of the GNU General Public License along
19with this program; if not, write to the Free Software Foundation, Inc., 59
20Temple Place, Suite 330, Boston, MA 02111-1307 USA
21
22  Should you need to contact me, the author, you can do so either by e-mail
23- mail your message to <vojtech@suse.cz>, or by paper mail: Vojtech Pavlik,
24Ucitelska 1576, Prague 8, 182 00 Czech Republic
25
26  For your convenience, the GNU General Public License version 2 is included
27in the package: See the file COPYING.
28
291. Usage
30~~~~~~~~
31  The drivers/usb/acm.c drivers works with USB modems and USB ISDN terminal
32adapters that conform to the Universal Serial Bus Communication Device Class
33Abstract Control Model (USB CDC ACM) specification.
34
35  Many modems do, here is a list of those I know of:
36
37	3Com OfficeConnect 56k
38	3Com Voice FaxModem Pro
39	3Com Sportster
40	MultiTech MultiModem 56k
41	Zoom 2986L FaxModem
42	Compaq 56k FaxModem
43	ELSA Microlink 56k
44
45  I know of one ISDN TA that does work with the acm driver:
46
47	3Com USR ISDN Pro TA
48
49  Unfortunately many modems and most ISDN TAs use proprietary interfaces and
50thus won't work with this drivers. Check for ACM compliance before buying.
51
52  The driver (with devfs) creates these devices in /dev/usb/acm:
53
54	crw-r--r--   1 root     root     166,   0 Apr  1 10:49 0
55	crw-r--r--   1 root     root     166,   1 Apr  1 10:49 1
56	crw-r--r--   1 root     root     166,   2 Apr  1 10:49 2
57
58  And so on, up to 31, with the limit being possible to change in acm.c to up
59to 256, so you can use up to 256 USB modems with one computer (you'll need
60three USB cards for that, though).
61
62  If you don't use devfs, then you can create device nodes with the same
63minor/major numbers anywhere you want, but either the above location or
64/dev/usb/ttyACM0 is preferred.
65
66  To use the modems you need these modules loaded:
67
68	usbcore.o
69	usb-[uo]hci.o or uhci.o
70	acm.o
71
72  After that, the modem[s] should be accessible. You should be able to use
73minicom, ppp and mgetty with them.
74
752. Verifying that it works
76~~~~~~~~~~~~~~~~~~~~~~~~~~
77  The first step would be to check /proc/bus/usb/devices, it should look
78like this:
79
80T:  Bus=01 Lev=00 Prnt=00 Port=00 Cnt=00 Dev#=  1 Spd=12  MxCh= 2
81B:  Alloc=  0/900 us ( 0%), #Int=  0, #Iso=  0
82D:  Ver= 1.00 Cls=09(hub  ) Sub=00 Prot=00 MxPS= 8 #Cfgs=  1
83P:  Vendor=0000 ProdID=0000 Rev= 0.00
84S:  Product=USB UHCI Root Hub
85S:  SerialNumber=6800
86C:* #Ifs= 1 Cfg#= 1 Atr=40 MxPwr=  0mA
87I:  If#= 0 Alt= 0 #EPs= 1 Cls=09(hub  ) Sub=00 Prot=00 Driver=hub
88E:  Ad=81(I) Atr=03(Int.) MxPS=   8 Ivl=255ms
89T:  Bus=01 Lev=01 Prnt=01 Port=01 Cnt=01 Dev#=  2 Spd=12  MxCh= 0
90D:  Ver= 1.00 Cls=02(comm.) Sub=00 Prot=00 MxPS= 8 #Cfgs=  2
91P:  Vendor=04c1 ProdID=008f Rev= 2.07
92S:  Manufacturer=3Com Inc.
93S:  Product=3Com U.S. Robotics Pro ISDN TA
94S:  SerialNumber=UFT53A49BVT7
95C:  #Ifs= 1 Cfg#= 1 Atr=60 MxPwr=  0mA
96I:  If#= 0 Alt= 0 #EPs= 3 Cls=ff(vend.) Sub=ff Prot=ff Driver=acm
97E:  Ad=85(I) Atr=02(Bulk) MxPS=  64 Ivl=  0ms
98E:  Ad=04(O) Atr=02(Bulk) MxPS=  64 Ivl=  0ms
99E:  Ad=81(I) Atr=03(Int.) MxPS=  16 Ivl=128ms
100C:* #Ifs= 2 Cfg#= 2 Atr=60 MxPwr=  0mA
101I:  If#= 0 Alt= 0 #EPs= 1 Cls=02(comm.) Sub=02 Prot=01 Driver=acm
102E:  Ad=81(I) Atr=03(Int.) MxPS=  16 Ivl=128ms
103I:  If#= 1 Alt= 0 #EPs= 2 Cls=0a(data ) Sub=00 Prot=00 Driver=acm
104E:  Ad=85(I) Atr=02(Bulk) MxPS=  64 Ivl=  0ms
105E:  Ad=04(O) Atr=02(Bulk) MxPS=  64 Ivl=  0ms
106
107The presence of these three lines (and the Cls= 'comm' and 'data' classes)
108is important, it means it's an ACM device. The Driver=acm means the acm
109driver is used for the device. If you see only Cls=ff(vend.) then you're out
110of luck, you have a device with vendor specific-interface.
111
112D:  Ver= 1.00 Cls=02(comm.) Sub=00 Prot=00 MxPS= 8 #Cfgs=  2
113I:  If#= 0 Alt= 0 #EPs= 1 Cls=02(comm.) Sub=02 Prot=01 Driver=acm
114I:  If#= 1 Alt= 0 #EPs= 2 Cls=0a(data ) Sub=00 Prot=00 Driver=acm
115
116In the system log you should see:
117
118usb.c: USB new device connect, assigned device number 2
119usb.c: kmalloc IF c7691fa0, numif 1
120usb.c: kmalloc IF c7b5f3e0, numif 2
121usb.c: skipped 4 class/vendor specific interface descriptors
122usb.c: new device strings: Mfr=1, Product=2, SerialNumber=3
123usb.c: USB device number 2 default language ID 0x409
124Manufacturer: 3Com Inc.
125Product: 3Com U.S. Robotics Pro ISDN TA
126SerialNumber: UFT53A49BVT7
127acm.c: probing config 1
128acm.c: probing config 2
129ttyACM0: USB ACM device
130acm.c: acm_control_msg: rq: 0x22 val: 0x0 len: 0x0 result: 0
131acm.c: acm_control_msg: rq: 0x20 val: 0x0 len: 0x7 result: 7
132usb.c: acm driver claimed interface c7b5f3e0
133usb.c: acm driver claimed interface c7b5f3f8
134usb.c: acm driver claimed interface c7691fa0
135
136If all this seems to be OK, fire up minicom and set it to talk to the ttyACM
137device and try typing 'at'. If it responds with 'OK', then everything is
138working.
139