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/class/cdc-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  Some cell phones also connect via USB. I know the following phones work:
 50
 51	SonyEricsson K800i
 52
 53  Unfortunately many modems and most ISDN TAs use proprietary interfaces and
 54thus won't work with this drivers. Check for ACM compliance before buying.
 55
 56  To use the modems you need these modules loaded:
 57
 58	usbcore.ko
 59	uhci-hcd.ko ohci-hcd.ko or ehci-hcd.ko
 60	cdc-acm.ko
 61
 62  After that, the modem[s] should be accessible. You should be able to use
 63minicom, ppp and mgetty with them.
 64
 652. Verifying that it works
 66~~~~~~~~~~~~~~~~~~~~~~~~~~
 67  The first step would be to check /proc/bus/usb/devices, it should look
 68like this:
 69
 70T:  Bus=01 Lev=00 Prnt=00 Port=00 Cnt=00 Dev#=  1 Spd=12  MxCh= 2
 71B:  Alloc=  0/900 us ( 0%), #Int=  0, #Iso=  0
 72D:  Ver= 1.00 Cls=09(hub  ) Sub=00 Prot=00 MxPS= 8 #Cfgs=  1
 73P:  Vendor=0000 ProdID=0000 Rev= 0.00
 74S:  Product=USB UHCI Root Hub
 75S:  SerialNumber=6800
 76C:* #Ifs= 1 Cfg#= 1 Atr=40 MxPwr=  0mA
 77I:  If#= 0 Alt= 0 #EPs= 1 Cls=09(hub  ) Sub=00 Prot=00 Driver=hub
 78E:  Ad=81(I) Atr=03(Int.) MxPS=   8 Ivl=255ms
 79T:  Bus=01 Lev=01 Prnt=01 Port=01 Cnt=01 Dev#=  2 Spd=12  MxCh= 0
 80D:  Ver= 1.00 Cls=02(comm.) Sub=00 Prot=00 MxPS= 8 #Cfgs=  2
 81P:  Vendor=04c1 ProdID=008f Rev= 2.07
 82S:  Manufacturer=3Com Inc.
 83S:  Product=3Com U.S. Robotics Pro ISDN TA
 84S:  SerialNumber=UFT53A49BVT7
 85C:  #Ifs= 1 Cfg#= 1 Atr=60 MxPwr=  0mA
 86I:  If#= 0 Alt= 0 #EPs= 3 Cls=ff(vend.) Sub=ff Prot=ff Driver=acm
 87E:  Ad=85(I) Atr=02(Bulk) MxPS=  64 Ivl=  0ms
 88E:  Ad=04(O) Atr=02(Bulk) MxPS=  64 Ivl=  0ms
 89E:  Ad=81(I) Atr=03(Int.) MxPS=  16 Ivl=128ms
 90C:* #Ifs= 2 Cfg#= 2 Atr=60 MxPwr=  0mA
 91I:  If#= 0 Alt= 0 #EPs= 1 Cls=02(comm.) Sub=02 Prot=01 Driver=acm
 92E:  Ad=81(I) Atr=03(Int.) MxPS=  16 Ivl=128ms
 93I:  If#= 1 Alt= 0 #EPs= 2 Cls=0a(data ) Sub=00 Prot=00 Driver=acm
 94E:  Ad=85(I) Atr=02(Bulk) MxPS=  64 Ivl=  0ms
 95E:  Ad=04(O) Atr=02(Bulk) MxPS=  64 Ivl=  0ms
 96
 97The presence of these three lines (and the Cls= 'comm' and 'data' classes)
 98is important, it means it's an ACM device. The Driver=acm means the acm
 99driver is used for the device. If you see only Cls=ff(vend.) then you're out
100of luck, you have a device with vendor specific-interface.
101
102D:  Ver= 1.00 Cls=02(comm.) Sub=00 Prot=00 MxPS= 8 #Cfgs=  2
103I:  If#= 0 Alt= 0 #EPs= 1 Cls=02(comm.) Sub=02 Prot=01 Driver=acm
104I:  If#= 1 Alt= 0 #EPs= 2 Cls=0a(data ) Sub=00 Prot=00 Driver=acm
105
106In the system log you should see:
107
108usb.c: USB new device connect, assigned device number 2
109usb.c: kmalloc IF c7691fa0, numif 1
110usb.c: kmalloc IF c7b5f3e0, numif 2
111usb.c: skipped 4 class/vendor specific interface descriptors
112usb.c: new device strings: Mfr=1, Product=2, SerialNumber=3
113usb.c: USB device number 2 default language ID 0x409
114Manufacturer: 3Com Inc.
115Product: 3Com U.S. Robotics Pro ISDN TA
116SerialNumber: UFT53A49BVT7
117acm.c: probing config 1
118acm.c: probing config 2
119ttyACM0: USB ACM device
120acm.c: acm_control_msg: rq: 0x22 val: 0x0 len: 0x0 result: 0
121acm.c: acm_control_msg: rq: 0x20 val: 0x0 len: 0x7 result: 7
122usb.c: acm driver claimed interface c7b5f3e0
123usb.c: acm driver claimed interface c7b5f3f8
124usb.c: acm driver claimed interface c7691fa0
125
126If all this seems to be OK, fire up minicom and set it to talk to the ttyACM
127device and try typing 'at'. If it responds with 'OK', then everything is
128working.