On Thu, 26 Feb 2009 13:48:30 -0800
David Brownell <david-b@xxxxxxxxxxx> wrote:
> From: David Brownell <dbrownell@xxxxxxxxxxxxxxxxxxxxx>
>
> Add optional glue between MMC and regulator stacks, using a new
> regulator interface to learn what voltages are available.
>
> This is intended to be selected and driven by MMC host adapters.
> It only handles reusable parts of the regulator-to-MMC glue; the
> adapter drivers will have access to details that affect how this
> is used. Examples include when to use multiple voltage rails or
> configure (internal or external) level shifters.
>
> Signed-off-by: David Brownell <dbrownell@xxxxxxxxxxxxxxxxxxxxx>
> ---
> Changes from previous version: adapter must select this, and
> callers now pass in the regulator. mmc_regulator_set_ocr()
> is still not tested, mmc_regulator_get_ocrmask() passed sanity
> testing.
>
> Pierre: Mark may have a need for this soonish. The omap_hsmmc
> code will want it at some point.
>
I have no insight into the regulator stuff, so I'm going to have to
trust you on this. :)
Some nitpicking though:
> --- a/drivers/mmc/core/Kconfig
> +++ b/drivers/mmc/core/Kconfig
> @@ -14,3 +14,10 @@ config MMC_UNSAFE_RESUME
> This option is usually just for embedded systems which use
> a MMC/SD card for rootfs. Most people should say N here.
>
> +config MMC_REGULATOR
> + bool
> + depends on REGULATOR
> + help
> + Select this if your MMC host adapter driver wants helper
> + utilities for accessing power rails.
> +
Is there a need for a special Kconfig for this? Can't we just build
these two whenever REGULATOR is defined? Or always, provided the
regulator API is present even when the code isn't.
> +/**
> + * mmc_regulator_set_ocr - set regulator to match host->ios voltage
> + * @host: mmc host whose supply voltage will be changed
> + * @supply: regulator to use
> + *
> + * MMC host drivers may use this to enable or disable a regulator using
> + * a particular supply voltage. This would normally be called from the
> + * set_ios() method.
> + */
> +int mmc_regulator_set_ocr(struct mmc_host *host, struct regulator *supply)
> +{
Why not pass the vdd directly? Saves a few dereferences if nothing else.
Rgds
--
-- Pierre Ossman
Linux kernel, MMC maintainer http://www.kernel.org
rdesktop, core developer http://www.rdesktop.org
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