From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ben Dooks Subject: Re: [PATCH 7/9] I2C: MV64XXX: Add Device Tree support Date: Tue, 26 Jun 2012 15:13:46 +0100 Message-ID: <4FE9C39A.2080104@codethink.co.uk> References: <1339324322-29388-8-git-send-email-andrew@lunn.ch> <4FE9C14C.2030804@codethink.co.uk> <20120626141047.GA18804@lunn.ch> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Andrew Lunn , jason-NLaQJdtUoK4Be96aLqz0jA@public.gmane.org, devicetree-discuss-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org, rob.herring-bsGFqQB8/DxBDgjK7y7TUQ@public.gmane.org, grant.likely-s3s/WqlpOiPyB63q8FvJNQ@public.gmane.org, linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, spi-devel-general-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org, machael-QKn5cuLxLXY@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org Return-path: In-Reply-To: <20120626141047.GA18804-g2DYL2Zd6BY@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: spi-devel-general-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org List-Id: linux-spi.vger.kernel.org On 26/06/12 15:10, Andrew Lunn wrote: > On Tue, Jun 26, 2012 at 03:03:56PM +0100, Ben Dooks wrote: >> On 10/06/12 11:31, Andrew Lunn wrote: >>> Extends the driver to get properties from device tree. Also extend the >>> kirkwood DT support to supply the needed properties. >>> >>> Signed-off-by: Andrew Lunn >>> --- >>> Documentation/devicetree/bindings/i2c/mrvl-i2c.txt | 35 +++++++++++++++++- >>> arch/arm/boot/dts/kirkwood.dtsi | 13 +++++++ >>> arch/arm/mach-kirkwood/board-dt.c | 2 ++ >>> drivers/i2c/busses/i2c-mv64xxx.c | 38 +++++++++++++++++--- >>> 4 files changed, 82 insertions(+), 6 deletions(-) >>> >>> diff --git a/Documentation/devicetree/bindings/i2c/mrvl-i2c.txt b/Documentation/devicetree/bindings/i2c/mrvl-i2c.txt >>> index b891ee2..89ef899 100644 >>> --- a/Documentation/devicetree/bindings/i2c/mrvl-i2c.txt >>> +++ b/Documentation/devicetree/bindings/i2c/mrvl-i2c.txt >>> @@ -1,4 +1,4 @@ >>> -* I2C >>> +* Marvell MMP I2C controller >>> >>> Required properties : >>> >>> @@ -32,3 +32,36 @@ Examples: >>> interrupts =<58>; >>> }; >>> >>> +* Marvell MV64XXX I2C controller >>> + >>> +Required properties : >>> + >>> + - reg : Offset and length of the register set for the device >>> + - compatible : should be "marvell,mv64xxx-i2c" >>> + - interrupts : the interrupt number >>> + - frequency-m : m factor in baud rate calculation >>> + >>> +Recommended properties : >>> + >>> + - frequency-n : n factor in baud rate calculation >>> + - timeout-ms : How long to wait for a transaction to complete >>> + >>> +Baud Rate: >>> + >>> +The baud rate is calculated thus: >>> + >>> +Fscl = Ftclk >>> + ------------------------------------------ >>> + (frequency-n + 1) >>> + 10 *(frequency-m + 1) * 2 >>> + >>> +Examples: >> >> I'd really rather see this calculated at run-time, given some >> systems can quite easily change their clocks. > > Hi Ben > > Well, none of the Orion systems would make use of this. They all have > fixed clocks. > > Maybe the new Armada XP systems could make use of clock scaling? A couple of the development boards here have dip-switches to change the clocks at start-time, and thus having something that does this would be useful. PS, for other people's info, this bounces to the i2c list due to the use of 'xxx' in the title :( -- Ben Dooks http://www.codethink.co.uk/ Senior Engineer Codethink - Providing Genius ------------------------------------------------------------------------------ Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/