On 26/06/12 15:10, Andrew Lunn wrote:

On Tue, Jun 26, 2012 at 03:03:56PM +0100, Ben Dooks wrote:

quoted

On 10/06/12 11:31, Andrew Lunn wrote:

quoted

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@lunn.ch>
---
  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