Hi Thomas,

On 8/22/2012 2:04 AM, Thomas Abraham wrote:

On 22 August 2012 16:38, Chris Ball [off-list ref] wrote:

quoted

Hi Thomas,

On Wed, Aug 22 2012, Thomas Abraham wrote:

quoted

quoted

This matches Mitch's last suggestion exactly -- I think we're all agreed
on these properties now.  The only remaining question is how to handle
the pinctrl for CD in Thomas's case.

Hi Chris,

For sdhci-s3c driver, the 'broken-cd' and 'cd-gpios' bindings are
sufficient. But, are drivers free to use implementation specific
behavior when using these bindings. Or do we strictly adhere to the
table which Shawn has listed. For sdhci-s3c driver, I would like to
deviate from the "implication" column listed above.

I'd rather you use the implications described above for the names
described above; there's not much point in defining named behaviors
across the subsystem if they're actually different in each driver.

Ok.

quoted

But I think you can still use driver-internal properties that change the
interpretation of those names in a documented way.  If the meaning of
cd-gpios is modified when coupled with your "samsung,sdhci-cd-external",
that's okay with me.  That should cover all the cases you need until you
migrate to using pinctrl, right?  So, you could immediately support:

none          -> currently "samsung,sdhci-cd-internal"
broken-cd     -> currently "samsung,sdhci-cd-none"
cd-gpios      -> currently "samsung,sdhci-cd-gpios"
non-removable -> currently "samsung,sdhci-cd-permanent"
cd-gpios + samsung,sdhci-cd-external -> currently "samsung,sdhci-cd-external"

How does that sound?

Not quite there yet. It is not possible to leave out cd-gpios for
"samsung,sdhci-cd-internal" since the current Samsung pinmux
configuration piggybacks on gpio dt binding.

Sorry to interject on a topic that seems to have already been decided,
but I'm confused by one thing and would like clarification.  I
understand that you need to use a GPIO-style specifier as a surrogate
for a pinmux specification - that much is clear.  What is not clear is
why it's necessary to (ab)use the name "cd-gpios" for it.

Why not use a different property name, e.g. "samsung,cd-pinmux-gpio =
<gpio-specifier>" for the "cd-gpios + samsung,sdhci-cd-internal" case?
Then both "samsung,sdhci-cdi-internal" and "samsung,sdhci-cd-external"
could go away.  There would only be one system-dependent property
"samsung,cd-pinmux-gpio" whose name would make it clear that it's
conflating pinmuxing and gpios.

I think the scheme I propose would be clearer, less likely to confuse
other people who try to use the driver as a model, require less
hand-waving in the documentation, and easier to change to a proper
pinmuxing scheme should that become available later.


 Can we use the following

instead.

none               -> currently "samsung,sdhci-cd-none"
broken-cd        -> currently "samsung,sdhci-cd-none"
cd-gpios          -> currently "samsung,sdhci-cd-gpios"
non-removable -> currently "samsung,sdhci-cd-permanent"
cd-gpios + samsung,sdhci-cd-internal -> currently "samsung,sdhci-cd-internal"

Thanks Chris.

Regards,
Thomas.
_______________________________________________
devicetree-discuss mailing list
devicetree-discuss-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org
https://lists.ozlabs.org/listinfo/devicetree-discuss