1======================
  2Linux ACM driver v0.16
  3======================
  4
  5Copyright (c) 1999 Vojtech Pavlik <vojtech@suse.cz>
  6
  7Sponsored by SuSE
  8
  90. Disclaimer
 10~~~~~~~~~~~~~
 11This program is free software; you can redistribute it and/or modify it
 12under the terms of the GNU General Public License as published by the Free
 13Software Foundation; either version 2 of the License, or (at your option)
 14any later version.
 15
 16This program is distributed in the hope that it will be useful, but
 17WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
 18or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 19more details.
 20
 21You should have received a copy of the GNU General Public License along
 22with this program; if not, write to the Free Software Foundation, Inc., 59
 23Temple Place, Suite 330, Boston, MA 02111-1307 USA
 24
 25Should you need to contact me, the author, you can do so either by e-mail -
 26mail your message to <vojtech@suse.cz>, or by paper mail: Vojtech Pavlik,
 27Ucitelska 1576, Prague 8, 182 00 Czech Republic
 28
 29For your convenience, the GNU General Public License version 2 is included
 30in the package: See the file COPYING.
 31
 321. Usage
 33~~~~~~~~
 34The drivers/usb/class/cdc-acm.c drivers works with USB modems and USB ISDN terminal
 35adapters that conform to the Universal Serial Bus Communication Device Class
 36Abstract Control Model (USB CDC ACM) specification.
 37
 38Many modems do, here is a list of those I know of:
 39
 40	- 3Com OfficeConnect 56k
 41	- 3Com Voice FaxModem Pro
 42	- 3Com Sportster
 43	- MultiTech MultiModem 56k
 44	- Zoom 2986L FaxModem
 45	- Compaq 56k FaxModem
 46	- ELSA Microlink 56k
 47
 48I know of one ISDN TA that does work with the acm driver:
 49
 50	- 3Com USR ISDN Pro TA
 51
 52Some cell phones also connect via USB. I know the following phones work:
 53
 54	- SonyEricsson K800i
 55
 56Unfortunately many modems and most ISDN TAs use proprietary interfaces and
 57thus won't work with this drivers. Check for ACM compliance before buying.
 58
 59To use the modems you need these modules loaded::
 60
 61	usbcore.ko
 62	uhci-hcd.ko ohci-hcd.ko or ehci-hcd.ko
 63	cdc-acm.ko
 64
 65After that, the modem[s] should be accessible. You should be able to use
 66minicom, ppp and mgetty with them.
 67
 682. Verifying that it works
 69~~~~~~~~~~~~~~~~~~~~~~~~~~
 70
 71The first step would be to check /sys/kernel/debug/usb/devices, it should look
 72like this::
 73
 74  T:  Bus=01 Lev=00 Prnt=00 Port=00 Cnt=00 Dev#=  1 Spd=12  MxCh= 2
 75  B:  Alloc=  0/900 us ( 0%), #Int=  0, #Iso=  0
 76  D:  Ver= 1.00 Cls=09(hub  ) Sub=00 Prot=00 MxPS= 8 #Cfgs=  1
 77  P:  Vendor=0000 ProdID=0000 Rev= 0.00
 78  S:  Product=USB UHCI Root Hub
 79  S:  SerialNumber=6800
 80  C:* #Ifs= 1 Cfg#= 1 Atr=40 MxPwr=  0mA
 81  I:  If#= 0 Alt= 0 #EPs= 1 Cls=09(hub  ) Sub=00 Prot=00 Driver=hub
 82  E:  Ad=81(I) Atr=03(Int.) MxPS=   8 Ivl=255ms
 83  T:  Bus=01 Lev=01 Prnt=01 Port=01 Cnt=01 Dev#=  2 Spd=12  MxCh= 0
 84  D:  Ver= 1.00 Cls=02(comm.) Sub=00 Prot=00 MxPS= 8 #Cfgs=  2
 85  P:  Vendor=04c1 ProdID=008f Rev= 2.07
 86  S:  Manufacturer=3Com Inc.
 87  S:  Product=3Com U.S. Robotics Pro ISDN TA
 88  S:  SerialNumber=UFT53A49BVT7
 89  C:  #Ifs= 1 Cfg#= 1 Atr=60 MxPwr=  0mA
 90  I:  If#= 0 Alt= 0 #EPs= 3 Cls=ff(vend.) Sub=ff Prot=ff Driver=acm
 91  E:  Ad=85(I) Atr=02(Bulk) MxPS=  64 Ivl=  0ms
 92  E:  Ad=04(O) Atr=02(Bulk) MxPS=  64 Ivl=  0ms
 93  E:  Ad=81(I) Atr=03(Int.) MxPS=  16 Ivl=128ms
 94  C:* #Ifs= 2 Cfg#= 2 Atr=60 MxPwr=  0mA
 95  I:  If#= 0 Alt= 0 #EPs= 1 Cls=02(comm.) Sub=02 Prot=01 Driver=acm
 96  E:  Ad=81(I) Atr=03(Int.) MxPS=  16 Ivl=128ms
 97  I:  If#= 1 Alt= 0 #EPs= 2 Cls=0a(data ) Sub=00 Prot=00 Driver=acm
 98  E:  Ad=85(I) Atr=02(Bulk) MxPS=  64 Ivl=  0ms
 99  E:  Ad=04(O) Atr=02(Bulk) MxPS=  64 Ivl=  0ms
100
101The presence of these three lines (and the Cls= 'comm' and 'data' classes)
102is important, it means it's an ACM device. The Driver=acm means the acm
103driver is used for the device. If you see only Cls=ff(vend.) then you're out
104of luck, you have a device with vendor specific-interface::
105
106  D:  Ver= 1.00 Cls=02(comm.) Sub=00 Prot=00 MxPS= 8 #Cfgs=  2
107  I:  If#= 0 Alt= 0 #EPs= 1 Cls=02(comm.) Sub=02 Prot=01 Driver=acm
108  I:  If#= 1 Alt= 0 #EPs= 2 Cls=0a(data ) Sub=00 Prot=00 Driver=acm
109
110In the system log you should see::
111
112  usb.c: USB new device connect, assigned device number 2
113  usb.c: kmalloc IF c7691fa0, numif 1
114  usb.c: kmalloc IF c7b5f3e0, numif 2
115  usb.c: skipped 4 class/vendor specific interface descriptors
116  usb.c: new device strings: Mfr=1, Product=2, SerialNumber=3
117  usb.c: USB device number 2 default language ID 0x409
118  Manufacturer: 3Com Inc.
119  Product: 3Com U.S. Robotics Pro ISDN TA
120  SerialNumber: UFT53A49BVT7
121  acm.c: probing config 1
122  acm.c: probing config 2
123  ttyACM0: USB ACM device
124  acm.c: acm_control_msg: rq: 0x22 val: 0x0 len: 0x0 result: 0
125  acm.c: acm_control_msg: rq: 0x20 val: 0x0 len: 0x7 result: 7
126  usb.c: acm driver claimed interface c7b5f3e0
127  usb.c: acm driver claimed interface c7b5f3f8
128  usb.c: acm driver claimed interface c7691fa0
129
130If all this seems to be OK, fire up minicom and set it to talk to the ttyACM
131device and try typing 'at'. If it responds with 'OK', then everything is
132working.