From: Mark Brown <broonie@opensource.wolfsonmicro.com>
To: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Cc: linux-mmc@vger.kernel.org, linux-sh@vger.kernel.org
Subject: Re: [PATCH 07/29] mmc: add a function to get a regulator, supplying card's Vdd
Date: Fri, 18 May 2012 15:18:38 +0000 [thread overview]
Message-ID: <20120518151837.GD4039@opensource.wolfsonmicro.com> (raw)
In-Reply-To: <Pine.LNX.4.64.1205181059560.23140@axis700.grange>
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On Fri, May 18, 2012 at 11:28:31AM +0200, Guennadi Liakhovetski wrote:
> 1. A regulator that can (in principle) change state, i.e., switch on and
> off. Such a regulator is good to keep for the runtime to power up and down
> the card.
> 2. A regulator, that cannot switch, but at least can tell its supplied
> voltage is used ones to read out supported voltages and released again.
This doesn't make sense, you can only change the voltages if you hold a
reference to the regulator.
> 3. A regulator that can do none of the above is defined as "useless"
> > You may also run into trouble on boards that use the ability to disable
> > unused regulators at the end of boot - they'll power things off even
> > without the ability to change status at runtime.
> Aha, you mean, I shouldn't put() the regulator, even if it cannot change
> status itself?
Yes, you ought to to be safe and like I say if you want to manage the
voltage then you need to keep a reference to the regulator.
> Can this also happen with a dummy regulator?
Obviously not, though if you've got explicit code in to handle dummy
regulators you're rather missing the point. Their entire purpose is to
provide a crutch to keep the system going if bits are missing from the
bindings, they're not intended to be used in production.
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next prev parent reply other threads:[~2012-05-18 15:18 UTC|newest]
Thread overview: 61+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-05-03 15:05 [PATCH 00/29] mmc: mmcif and tmio regulator and OF support Guennadi Liakhovetski
2012-05-03 15:05 ` [PATCH 01/29] mmc: sh_mmcif: remove redundant .down_pwr() callback Guennadi Liakhovetski
2012-05-03 15:05 ` [PATCH 02/29] sh: ecovec: remove unused .down_pwr() MMCIF callback Guennadi Liakhovetski
2012-05-03 15:05 ` [PATCH 03/29] mmc: sh_mmcif: remove unused .down_pwr() callback Guennadi Liakhovetski
2012-05-03 15:05 ` [PATCH 04/29] regulator: fix devm_regulator_put() to call regulator_put() explicitly Guennadi Liakhovetski
2012-05-03 16:56 ` Mark Brown
2012-05-18 8:54 ` Guennadi Liakhovetski
2012-05-18 15:10 ` Mark Brown
2012-05-03 15:05 ` [PATCH 05/29] regulator: use IS_ERR_OR_NULL() instead of open-coding Guennadi Liakhovetski
2012-05-03 15:32 ` Mark Brown
2012-05-18 8:44 ` Guennadi Liakhovetski
2012-05-18 8:57 ` Paul Mundt
2012-05-18 9:18 ` Guennadi Liakhovetski
2012-05-18 9:19 ` Paul Mundt
2012-05-18 15:04 ` Mark Brown
2012-06-11 11:38 ` Guennadi Liakhovetski
2012-06-11 11:51 ` Mark Brown
2012-06-11 12:06 ` Guennadi Liakhovetski
2012-06-11 12:15 ` Mark Brown
2012-05-03 15:05 ` [PATCH 06/29] regulator: export a function to check if regulator can change status Guennadi Liakhovetski
2012-05-03 15:25 ` Mark Brown
2012-05-18 8:33 ` Guennadi Liakhovetski
2012-05-18 15:08 ` Mark Brown
2012-05-18 15:23 ` Guennadi Liakhovetski
2012-05-03 15:05 ` [PATCH 07/29] mmc: add a function to get a regulator, supplying card's Vdd Guennadi Liakhovetski
2012-05-03 15:42 ` Mark Brown
2012-05-18 9:28 ` Guennadi Liakhovetski
2012-05-18 15:18 ` Mark Brown [this message]
2012-05-18 15:39 ` Guennadi Liakhovetski
2012-05-18 16:04 ` Mark Brown
2012-05-03 15:05 ` [PATCH 08/29] mmc: sh_mmcif: add regulator support Guennadi Liakhovetski
2012-05-03 15:45 ` Mark Brown
2012-05-18 9:35 ` Guennadi Liakhovetski
2012-05-03 15:05 ` [PATCH 09/29] mmc: tmio: stop interface clock before runtime PM suspending Guennadi Liakhovetski
2012-05-03 15:05 ` [PATCH 10/29] mmc: tmio: don't needlessly enable interrupts during probing Guennadi Liakhovetski
2012-05-03 15:05 ` [PATCH 11/29] mmc: tmio: add callbacks to enable-update and disable the interface clock Guennadi Liakhovetski
2012-05-03 15:05 ` [PATCH 12/29] mmc: sdhi: implement tmio-mmc clock enable-update and disable callbacks Guennadi Liakhovetski
2012-05-03 15:05 ` [PATCH 13/29] mmc: tmio: add regulator support Guennadi Liakhovetski
2012-05-03 15:56 ` Mark Brown
2012-05-18 9:55 ` Guennadi Liakhovetski
2012-05-18 15:34 ` Mark Brown
2012-05-03 15:05 ` [PATCH 14/29] mmc: sdhi: do not install dummy callbacks Guennadi Liakhovetski
2012-05-03 15:05 ` [PATCH 15/29] mmc: extend and rename cd-gpio helpers to handle more slot GPIO functions Guennadi Liakhovetski
2012-05-17 14:28 ` S, Venkatraman
2012-05-03 15:05 ` [PATCH 16/29] mmc: tmio: use MMC opcode defines instead of numbers Guennadi Liakhovetski
2012-05-03 15:05 ` [PATCH 17/29] mmc: use a more generic name for slot function types and fields Guennadi Liakhovetski
2012-05-03 15:05 ` [PATCH 18/29] mmc: tmio: remove a duplicated comment line Guennadi Liakhovetski
2012-05-03 15:05 ` [PATCH 19/29] mmc: add two capability flags for CD and WP signal polarity Guennadi Liakhovetski
2012-05-03 15:05 ` [PATCH 20/29] mmc: add CD GPIO polling support to slot functions Guennadi Liakhovetski
2012-05-03 15:05 ` [PATCH 21/29] mmc: convert slot functions to managed allocation Guennadi Liakhovetski
2012-05-03 15:05 ` [PATCH 22/29] mmc: add WP pin handler to slot functions Guennadi Liakhovetski
2012-05-03 15:05 ` [PATCH 23/29] mmc: tmio: use generic GPIO CD and WP handlers Guennadi Liakhovetski
2012-05-03 15:05 ` [PATCH 24/29] mmc: add a simple generic OF parser Guennadi Liakhovetski
2012-05-04 18:26 ` Olof Johansson
2012-05-18 9:58 ` Guennadi Liakhovetski
2012-05-10 7:51 ` Magnus Damm
2012-05-03 15:05 ` [PATCH 25/29] mmc: tmio: add OF support Guennadi Liakhovetski
2012-05-03 15:05 ` [PATCH 26/29] mmc: sdhi: add OF support, make platform data optional Guennadi Liakhovetski
2012-05-03 15:05 ` [PATCH 27/29] mmc: mmcif: add OF support Guennadi Liakhovetski
2012-05-03 15:05 ` [PATCH 28/29] mmc: mmcif: add support for generic GPIO CD polling Guennadi Liakhovetski
2012-05-03 15:05 ` [PATCH 29/29] sh: ecovec: switch MMC power control to regulators Guennadi Liakhovetski
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