Date: Fri, 9 Jul 1999 18:38:43 -0400 (EDT) From: Bill Paul <wpaul@skynet.ctr.columbia.edu> To: hackers@freebsd.org Subject: PCCARD and Vpp voltage Message-ID: <199907092238.SAA07224@skynet.ctr.columbia.edu>
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Today I started experimenting with the Aironet 4800 series 11Mbps
wireless networking cards. Aironet makes PCMCIA, ISA and PCI adapters.
I happen to have the PCMCIA and ISA ones. Like the Lucent WaveLAN/IEEE
cards, the ISA and PCI cards are really PCMCIA cards fitted into a
bridge adapter. Unlike the WaveLAN/IEEE cards, the bridge adapters
look like real ISA or PCI devices to the host, so you don't need
PCCARD support to use them. (The Lucent WaveLAN/IEEE ISA card requires
PCCARD support in order to work.)
Anyway, that's not why I'm here. My problem is the PCMCIA adapter.
I'm testing it on a Dell Latitude Cpi D300XT, which has both LoseNT 4.0
and FreeBSD 3.2 installed. I decided to install the PCMCIA card in the
laptop using the LoseNT drivers so that I could have a known working
machine with which to generate traffic so that I could properly test
the ISA card. However much to my surprise (well, not really), LoseNT
failed to detect the card. The 'PC Card (PCMCIA)' icon in the control
shows the PCMCIA modem in slot 1, but shows slot 0 as empty. Naturally,
the drivers from Aironet fail to attach the card.
So I decided to boot FreeBSD instead. Unfortunately, it didn't detect
the card either. After reading the Aironet manual (which I don't really
have -- shhhh), I found in the section on starting the card that you
have to "Enable power (VCC) to the socket and also set VPP1, VPP2 = 5V."
Looking in /sys/pccard/pccard.c:insert(), I found the following code:
/*
* Enable 5V to the card so that the CIS can be read.
*/
slt->pwr.vcc = 50;
slt->pwr.vpp = 0;
So, I changed this to
slt->pwr.vcc = 50;
slt->pwr.vpp = 50;
And now pccardc dumpcis shows all of the proper CIS information, pccardd
finds the card and life is good. (Frankly, I was stunned that I figured
this out; I'm not really that bright, you know.) Apparently, the Aironet
card wants VPP turned on before it will let you read the CIS table.
So, here are my questions:
- Why is the vpp voltage alwats left at 0?
- Is it safe for me to change the code so that it's set to 5 volts?
Obviously I'm going to need this change in order to make the Aironet
PCMCIA cards work.
- If it's not safe to default vpp to 5 volts, is there a safe way to
detect when it needs to be turned on and do it only for those cards
that need it?
-Bill
--
=============================================================================
-Bill Paul (212) 854-6020 | System Manager, Master of Unix-Fu
Work: wpaul@ctr.columbia.edu | Center for Telecommunications Research
Home: wpaul@skynet.ctr.columbia.edu | Columbia University, New York City
=============================================================================
"It is not I who am crazy; it is I who am mad!" - Ren Hoek, "Space Madness"
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