From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mark Brown Subject: Re: Arndale power management Date: Wed, 17 Jul 2013 12:33:52 +0100 Message-ID: <20130717113352.GQ22506@sirena.org.uk> References: <611CFE9D6FBBDC4B97935A5287A11345014441@XSERVER21B.campus.tue.nl> <20130716092345.28c8d655@amdc308.digital.local> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="+9uAEI//NVSmpZEF" Return-path: Content-Disposition: inline In-Reply-To: <20130716092345.28c8d655@amdc308.digital.local> Sender: cpufreq-owner@vger.kernel.org List-ID: To: Lukasz Majewski Cc: "Comaschi, F." , Lists linaro-kernel , Viresh Kumar , "cpufreq@vger.kernel.org" , Chander Kashyap , Linux PM List --+9uAEI//NVSmpZEF Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Tue, Jul 16, 2013 at 09:23:45AM +0200, Lukasz Majewski wrote: > > > Maybe it is > > > possible to communicate with the on-board PMIC?=20 > You can look into the PMIC spec if some detailed informations are > exposed. Moreover each battery shall be described by a model, which > PMIC uses e.g. for accurate charging. > PMICs at Exynos4 are communicating via I2C and provide information > about battery state of charge (SoC). You can monitor this value over > time and on this basis get (very coarse) estimation of power > consumption. =20 There are enormous difficulties in getting useful information from batteries and chargers - due to things like the battery chemistry changing over time and thermal dependencies what you get back is so coarse grained it's of very little use for power metering. There's also the fact that on the Arndale the charger isn't wired up accessibly. Power monitoring is generally done with test equipment rather than on board features - Versatile Express is very unusual here. The usual strategy at system level is to put an ammeter or power meter in line with the main power supply; otherwise you need the board to have test access to allow you to hook into individual supplies (typically done with jumpers in line with the supplies). > I can only give you a hint there (since I didn't worked with Arndale ... > yet) - measure current and voltage provided for SoC core Vdd plane. I've not checked the schematics but there's nothing visible on the board that I'd associate with current monitoring except the wall supply. --+9uAEI//NVSmpZEF Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.20 (GNU/Linux) iQIcBAEBAgAGBQJR5oEdAAoJELSic+t+oim9quMP/ApuAllYjkYABVamSltyGThr HX2McmdGwqi48nJNjFH3H+v048j9l7aJclQhNemWCSFVleMG4C6VPEdW7/NXBNqW D2ZNnx5rMyRuyQ+d3eyHj1nAc5USWRu6p1NVhEMQuqKQ7yADeuKXnYxgNML2OpEA COrz8gpkcNUrrzdy/hhXpY+L+Mg0Quqngb51f6djmfyhPOQ63dSqsSqREGAWg8Cd zCqWwTDU1JkzAAVuaZUkOrHFh5fsQH6Y2n2YTkX6GVsrfj+2U1Ec830kYzQUJ5ua 3xDvtcYhvIUfRYuf8+jShB96exU6ABC2xdgwGKv+aSsFIQQydqwzMa8JGNt9Tw39 BMlq67DdoIMK1RsWUKifCB8OQ+WsTRhiOf+ARP+0x1rfqOj9IiVYRBp5RL6Cn+Jl L+2o2Z3Py+PGexSjtJB+Y3xfYLYlMpg3TJ81ymEeQFyVLfkHo1qUWZ8xJUAA1NV1 kGY3ddwy2DzFFJvUlN/w/yhHLEDICmfJqFdR6rjHCKBIHch9txVIZWeR/92qE18K n1Oi1Bp8rbHUUTWJSzb6PO6xrJDyWx/XsTAnM0xw1l+p10AXc8b/tjAgdH3IcEOL JO1DJq8RVfijNMdzbu15jgqpJ9ujmQy3FHMnzbfiQ2Ib+0IlOShUKpQLWNfcft6D 9BBvY6M/3+EJOLCQsJuc =Jgmp -----END PGP SIGNATURE----- --+9uAEI//NVSmpZEF--