Re: [PATCH v3 06/13] mmc: tmio-mmc: define device-tree bindings

[Arnd Bergmann <arnd@arndb.de>]

On Thursday 07 February 2013, Simon Horman wrote:
> > Please write the binding in a way that does not refer to a specific
> > implementation in Linux: The binding should describe the hardware
> > independent of details in the driver. In particular, I think you
> > should not refer to the TMIO_MMC_BLKSZ_2BYTES etc macros but describe
> > in text what the flags are about.
> > 
> > Regarding the toshiba,mmc-wrprotect-disable property, would it be
> > enough to just check the presence of the wp-gpios property?
> > 
> > TMIO_MMC_BLKSZ_2BYTES seems to be set unconditionally in
> > sh_mobile_sdhi_probe and nowhere else, so I'd assume we don't
> > actually need to provide this here, but can keep that knowledge
> > implicit based on whether we're talking to sh_mobile_sdhi
> > or another tmio_mmc variant.
> > 
> > For the other last one, is that actually board specific, or just
> > a feature of a given chip? If we can tell by the SoC, then I'd
> > suggest using separate "compatible" properties instead, and
> > put a bitmask of features into the .data field of the of match
> > table. For all I can tell, SH7372 does not set it, while SH73A0,
> > R8A7740 and R8A7779 always do.
> 
> My understanding is that TMIO_MMC_HAS_IDLE_WAIT can be set based
> on the SoC in use.

Ok, thanks for the confirmation. Just to be clear: Either way (compatible
or separate property) works fine and can be used here. I tend to prefer
basing these things on the "compatible" string in order to keep
specific knowledge of the device internals out of the device tree
binding though.

	Arnd