Re: sata AHCI controller over non-PCI bus

[Sergei Shtylyov <sshtylyov@ru.mvista.com>]

Hello.

Subbrathnam, Swaminathan wrote:
> Hi,
>
>             I would like to post support for OMAPL138 SATA controller that is AHCI 1.1 compliant.  OMAPL138 is an ARM926 based platform.
>
> Current "ahci.c" assumes that AHCI is getting supported over PCI by default, whereas the SATA AHCI controller on OMAPL138 is connected to a non-PCI bus.  Since I am in the process of posting the support I would like to get the  opinion from the community on how to proceed on this front.

   Well, you're not the first with this problem, Marvell already had it.

>   I see the following 2 options today
>
> 1.       #ifdef the PCI specific code in ahci.c and implement the platform_device based implementation to support non-PCI AHCI controllers.
>   

   I don't think this is a community-acceptable option at all.

> 2.       Re-organize the ahci.c to abstract the AHCI functionalities from PCI, non-PCI bus dependencies.
>
> Currently we have implemented Option 1 in our internal tree to support SATA on OMAPL138 platform and it works well.  Ideally I would want to proceed with Option 2 but would like get feedback from the community before proceeding in this direction.

   See 
http://git.kernel.org/?p=linux/kernel/git/jgarzik/libata-dev.git;a=shortlog;h=libahci 
for Jeff Garzik's work on separating AHCI support from PCI.

MBR, Sergei