Re: [PATCH] mmc: omap_hsmmc: Update driver to support without regulators

From	Ulf Hansson <ulf.hansson@linaro.org>
Newsgroups	linux.kernel
Subject	Re: [PATCH] mmc: omap_hsmmc: Update driver to support without regulators
Date	2015-07-22 14:10 +0200
Message-ID	<pP10u-6mP-25@gated-at.bofh.it> (permalink)
References	<pMedz-1pd-7@gated-at.bofh.it> <pOEdA-7g6-1@gated-at.bofh.it> <pOLI5-16f-1@gated-at.bofh.it> <pP0H7-5KL-3@gated-at.bofh.it>
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[...]

> Hi Ulf,
>
> Just to clarify do you have an issue with this patch or in general
> you rather nothave !CONFIG_REGULATOR supported? If its the latter
> then wouldit be better to remove the !CONFIG_REGULATOR portion from
> this driver all together.

I don't like this patch as is, as it seems like you are replacing the
VMMC regulator that actually exist in HW by parsing a DT property.

I think mmc_of_parse_voltage() shall *only* be used when the OCR mask
(->ocr_avail) can't be fetched by using a regulator. Typically that's
when the VMMC voltage levels are managed within the mmc controller
itself.

I don't have a strong opinion on how you solve that, but I guess you
have two options.

1.
Make sure the driver can be build and used both for CONFIG_REGULATOR
and !CONFIG_REGULATOR. What you need to take care of then, is to
assign the ->ocr_avail mask to a default value in the case when it
can't be fetched from a regulator. Most mmc drivers has some kind of
fall-back mechanism like this.

For those SoC where you need/can control the VMMC regulator, make sure
those enables CONFIG_REGULATOR to get the proper behaviour by
omap_hsmmc.

2.
Force omap_hsmmc to be build with CONFIG_REGULATOR.

Kind regards
Uffe
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Thread

[PATCH] mmc: omap_hsmmc: Update driver to support without regulators Franklin S Cooper Jr <fcooper@ti.com> - 2015-07-14 21:40 +0200
  Re: [PATCH] mmc: omap_hsmmc: Update driver to support without regulators "Franklin S Cooper Jr." <fcooper@ti.com> - 2015-07-22 13:50 +0200
    Re: [PATCH] mmc: omap_hsmmc: Update driver to support without regulators Ulf Hansson <ulf.hansson@linaro.org> - 2015-07-22 14:10 +0200
      Re: [PATCH] mmc: omap_hsmmc: Update driver to support without regulators Kishon Vijay Abraham I <kishon@ti.com> - 2015-07-22 14:20 +0200

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