Messages in this thread |  | | Date | Fri, 6 Dec 2013 10:01:17 +0100 | From | Thomas Petazzoni <> | Subject | Re: [PATCH 2/3] ARM: sunxi: Add an ahci-platform compatible AHCI driver for the Allwinner SUNXi series of SoCs |
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Dear Tejun Heo,
On Wed, 4 Dec 2013 08:23:12 -0500, Tejun Heo wrote:
> > But again, point me (for dummies ;) in the right direction and I'll > > work on it with some help. > > Richard and Shawn recently worked on ahci_imx. Can you guys please > talk with each other and figure out what can be done to share as much > as possible among these new platform-specific drivers? I'd really > like to see the common things factored out as much as possible with > only the actual hardware differences described for each device.
Also, please Cc me on such discussions. I have a pending AHCI platform driver for another ARM SoC family. It is very similar to ahci_platform, but needs to do a few more things that are SoC specific (map an additional register area, and do some SoC-specific stuff with them).
For the moment, we're left with two approaches:
* Do what Oliver did, where the ahci_<foo> driver will do its own SoC-specific stuff, and then will register an additional platform_device to trigger the ->probe() of the generic ahci_platform driver. I must say I don't really like this solution, since it involves having two platform_device registered for the same piece of hardware (one platform_device to trigger the ->probe of ahci_<foo>, and another one to trigger the ->probe of ahci_platform).
* Duplicate in ahci_<foo> the (relatively small) amount of code that is present in ahci_platform.
From my point of view, ahci_platform should be turned into a small "library", that provides an API for ahci_<foo> drivers to 1/ do their own custom stuff and 2/ do the common ahci_platform stuff.
This way we avoid the registration of two platform_device for the same piece of hardware, and we avoid the duplication of code.
Want me to propose a RFC for this idea?
Best regards,
Thomas -- Thomas Petazzoni, CTO, Free Electrons Embedded Linux, Kernel and Android engineering http://free-electrons.com
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