Re: [PATCH 7/9] I2C: MV64XXX: Add Device Tree support

[Ben Dooks <ben.dooks-4yDnlxn2s6sWdaTGBSpHTA@public.gmane.org>]

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<andrew-g2DYL2Zd6BY@public.gmane.org>
> ---
>   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.

-- 
Ben Dooks				http://www.codethink.co.uk/
Senior Engineer				Codethink - Providing Genius

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