From mboxrd@z Thu Jan 1 00:00:00 1970 From: boris.brezillon@free-electrons.com (Boris BREZILLON) Date: Wed, 28 May 2014 21:46:54 +0200 Subject: [PATCH v3 0/6] mfd: axp20x: add AXP221 PMIC support In-Reply-To: <20140527194932.GD12304@sirena.org.uk> References: <1401183535-31003-1-git-send-email-boris.brezillon@free-electrons.com> <20140527194932.GD12304@sirena.org.uk> Message-ID: <53863D2E.7050008@free-electrons.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hello Mark, On 27/05/2014 21:49, Mark Brown wrote: > On Tue, May 27, 2014 at 11:38:49AM +0200, Boris BREZILLON wrote: > >> I'm still waiting for inputs regarding the ipsout regulator representation: > If you've got questions you need an answer to urgently it's possibly > best to highlight them outside of a series like this doing that helps > make it more obvious. Noted. I'll take care to send a separate mail next time. BTW, I don't if you've noticed, but patch 5 of this series implements helper functions to register several regulators from a regulator_desc and an of_regulator_match table (as you suggested). >> * The ipsout regulator is currently represented as a fixed regulator >> providing a 5v output, and this is not exactly the case. >> AFAIU (here's is the datasheet traduction if you want to check [1]), the >> ipsout output is a multiplexer that choose among vbus (5V), acin (12V >> which is then converted to 5V) and the battery power supply (3,5 -> 4,2 V). >> This means the output voltage of ipsout vary between 3,5V and 5V. >> How can we express this kind of muxer in the regulator framework (is there >> already something available ?) ? >> Note that the power supply selection is automatic, though we could force >> one power supply, but then we loose the ability to unplug one power supply >> without impacting the system. > This sounds like it may as well just be represented as an unregulated > supply - it's just the system root supply really. Nothing can rely on > the voltage anyway as it's going to vary randomly depending on what the > user does power wise and typically it'd only be used as a supply for > things that don't care about the specific voltage. Okay, I'm fine with that. Thanks. Boris -- Boris Brezillon, Free Electrons Embedded Linux and Kernel engineering http://free-electrons.com