On Monday 14 September 2015 06:11 PM, Vaibhav Hiremath wrote:

On Monday 14 September 2015 04:04 PM, Ulf Hansson wrote:

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On 14 September 2015 at 11:42, Vaibhav Hiremath
[off-list ref] wrote:

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On Monday 14 September 2015 03:00 PM, Ulf Hansson wrote:

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Could this be implemented by regulator API? From patch set 3/3, the
pxa1928
voltage_switch hook is to operate the IO pad registers, this
seems not
belong
to the SDHC IP core.

Not quite sure whether regulator would be right fit for this.

   From the patche[3/3], this can be achieved by abstracting the
IO PAD
as
regulators
then, we may not need to touch the core sdhci.c. But I'm not sure
whether
this
is the good solution or not.

Exactly...

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sdhci Maintainers and experts may have better
suggestions.

Thats is the reason I stamped it as a RFC :)

[...]

  From an mmc core perspective it would be preferred if you implement
this as a regulator (vqmmc).

Especially since we will soon have an API for how to set the I/O
voltages - and the intelligence within that API is not something we
would like to implement for each and every host driver.
https://lkml.org/lkml/2015/8/31/367

I would still consider this as a regulator specific and may not address
the IO configuration within the SoC which are module specific.
The API regulator_set_voltage_triplet() will not have intelligence to
differentiate whether the call is coming from MMC or somewhere else.

Note that, the IO pad voltage configuration which I am referring to is
MMC specific and applicable only when pad is configured in MMC mode. So
technically it is not simply common pad voltage configuration.


And I am still not sure regulator framework would be right fit for
this. Pinctrl would have been right fit, but...since I saw f_sdh30
driver is already doing this, which is easy fit; so adopted the same.

Pinctrl would work as well, or perhaps a combination of both pinctrl
and a regulator.

Not sure, how I can propagate "call coming from MMC/SD" to both
regulator and pinctrl.
Probably pinctrl would already know, but then it doesn't know the
voltage settings.

Let me spend some time, but atleast at this point I am not sure.

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On the side note,
Lets park this patch aside, till I get back with better option.

It would be nice if you could review other patches, let them notget
blocked due to this.


Thanks,
Vaibhav