From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mark Brown Date: Wed, 11 Jul 2012 14:44:50 +0000 Subject: Re: Device tree binding for DVFS table Message-Id: <20120711144449.GA23654@sirena.org.uk> List-Id: References: <4FFD77FE.8050206@nvidia.com> <4FFD87BD.2030206@gmail.com> In-Reply-To: <4FFD87BD.2030206@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-arm-kernel@lists.infradead.org On Wed, Jul 11, 2012 at 09:03:41AM -0500, Rob Herring wrote: > I'd expect a single property with freq/volt pairs or 2 properties for > freq and voltage where there is a 1:1 relationship (freq N uses voltage N). I strongly agree - the current proposal is very hard to read due to the separation between the voltage and frequency values. Some devices do also need to scale multiple rails together, especially when this gets used for I/O devices. I'd also expect to see a range of voltages for each frequency rather than a specific voltage; usually things are at least characterised with a specified tolerance. From mboxrd@z Thu Jan 1 00:00:00 1970 From: broonie@opensource.wolfsonmicro.com (Mark Brown) Date: Wed, 11 Jul 2012 15:44:50 +0100 Subject: Device tree binding for DVFS table In-Reply-To: <4FFD87BD.2030206@gmail.com> References: <4FFD77FE.8050206@nvidia.com> <4FFD87BD.2030206@gmail.com> Message-ID: <20120711144449.GA23654@sirena.org.uk> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Wed, Jul 11, 2012 at 09:03:41AM -0500, Rob Herring wrote: > I'd expect a single property with freq/volt pairs or 2 properties for > freq and voltage where there is a 1:1 relationship (freq N uses voltage N). I strongly agree - the current proposal is very hard to read due to the separation between the voltage and frequency values. Some devices do also need to scale multiple rails together, especially when this gets used for I/O devices. I'd also expect to see a range of voltages for each frequency rather than a specific voltage; usually things are at least characterised with a specified tolerance.