Subject: CF custom implementation

From: Kiran Thota <[email-masked]>
Date: Thu, 5 May 2005 15:37:56 -0700

Hello!,
  I am working on a MIPS-based processor SoC which has a custom CF implementation over Local Bus.
The CF doesnt support IO mode, interrupts,  32-bit support.
It has limited register support [no interface registers to reset the CF]. I am using 2.6.10 from linux-mips.
I have already written a PCMCIA/CF socket socket for the same.
The goal is to use the CF cards as memoy devices. Advise me on the path to take:

PCMCIA/CF ->CS/DS -> IDE [I found a patch to make IDE work in polled mode]
PCMCIA/CF -> CS/DS -> MTD [drivers/mtc/maps/pcmciamtd.c]

I am currently using Lexar and Hitachi Compact Flash cards.
The CIS can be read and when the Linux boots up and I invoke cardmgr [v3.2.8], it sees the device as 
ATA/IDE Fixed Disk [Func = 4 (Fixed Disk) ]
Is there a way to force it to come up in memory only mode? Please suggest.

Thanks,
Kiran

---

From: Ulrich Eckhardt <[email-masked]>
Date: Fri, 6 May 2005 09:13:50 +0200

Kiran Thota wrote:
> I am working on a MIPS-based processor SoC which has a custom CF
> implementation over Local Bus. The CF doesnt support IO mode, interrupts, 
> 32-bit support.
> It has limited register support [no interface registers to reset the CF]. I
> am using 2.6.10 from linux-mips. I have already written a PCMCIA/CF socket
> socket for the same.

Could you tell me where you found that patch?

> I am currently using Lexar and Hitachi Compact Flash cards.

CF is a standard, so this shouldn't matter.

> The CIS can be read and when the Linux boots up and I invoke cardmgr
> [v3.2.8], it sees the device as ATA/IDE Fixed Disk [Func = 4 (Fixed Disk) ]

I'm using a CF card attached to the PCMCIA interface of an Alchemy Au1100. 
Since my board only has a CF slot, I'm not using the whole PCMCIA stack at 
all - CONFIG_PCMCIA=no and no cardmgr. All I do is detect the card, parse the 
CIS and register the CF card with the IDE/ATA system of the kernel, just like 
Alan Cox suggested in the recent thread "ATA devices attached to arbitary 
busses". One good reason for me doing so is that I need to mount the root 
filesystem from the CF but the PCMCIA stack requires user-space helpers.

Uli