[ECOS] SD/MMC Bus Driver

[ECOS] SD/MMC Bus Driver

[Slide]

I'm going to try my hand at writing an SD/MMC bus driver for eCos and
contribute it. This will be the first real driver I've written for
eCos and I'd like some pointers. I've looked at a few drivers in Linux
and just code flows for the card initialization sequence and so forth.
For a single SD/MMC controller on a chip, there can be multiple cards
attached to the bus, and for a single chip, there can be multiple
SD/MMC controllers. I am not quite sure how to represent this in the
CDL and then the corresponding driver. I was thinking of defining a
host driver and then having a CDL integer number for the number of
SD/MMC controllers supported by the chip. Then, I was trying to figure
out a way to tell the disk bus driver which of those controllers to
check for cards.

My other thought is to start out more simple and support a single
controller on the chip and a single card attached to that controller,
then it could be expanded from there. Any thoughts from the community?

Thanks,

slide

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Re: [ECOS] SD/MMC Bus Driver

[Stefan Sommerfeld]

Hi Slice

> I'm going to try my hand at writing an SD/MMC bus driver for eCos and
> contribute it. This will be the first real driver I've written for
> eCos and I'd like some pointers. I've looked at a few drivers in Linux
> and just code flows for the card initialization sequence and so forth.
> For a single SD/MMC controller on a chip, there can be multiple cards
> attached to the bus, and for a single chip, there can be multiple
> SD/MMC controllers. I am not quite sure how to represent this in the
> CDL and then the corresponding driver. I was thinking of defining a
> host driver and then having a CDL integer number for the number of
> SD/MMC controllers supported by the chip. Then, I was trying to figure
> out a way to tell the disk bus driver which of those controllers to
> check for cards.
> 
> My other thought is to start out more simple and support a single
> controller on the chip and a single card attached to that controller,
> then it could be expanded from there. Any thoughts from the community?
> 

Did you make any progress on this? I need a SD card driver for a i.MX51 (which
has a sd simplified interface) and I'm willing to write one.

Maybe you or anyone else already has something as starting point.

Bye...

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