lkml.org 
[lkml]   [2014]   [Aug]   [20]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH 1/2] i2c: designware: device tree bindings for i2c speed mode
On Tue, Aug 19, 2014 at 07:34:35PM +0100, atull@opensource.altera.com wrote:
> From: Alan Tull <atull@opensource.altera.com>
>
> Add "speed-mode" Device Tree property to select between
> standard and fast i2c mode. Previously, driver was hardwired
> as fast mode. Default to fast mode if property is not
> present.
>
> Signed-off-by: Alan Tull <atull@opensource.altera.com>
> ---
> .../devicetree/bindings/i2c/i2c-designware.txt | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/Documentation/devicetree/bindings/i2c/i2c-designware.txt b/Documentation/devicetree/bindings/i2c/i2c-designware.txt
> index 5199b0c..0e4cd21 100644
> --- a/Documentation/devicetree/bindings/i2c/i2c-designware.txt
> +++ b/Documentation/devicetree/bindings/i2c/i2c-designware.txt
> @@ -9,6 +9,8 @@ Required properties :
> Recommended properties :
>
> - clock-frequency : desired I2C bus clock frequency in Hz.
> + - speed-mode : 0 = standard (0 - 100Kb/s)
> + : 1 = fast (<= 400Kb/s) <== default

This is a bit opaque.

Is this a limit on the max bit-rate the device should operate at?

Why not just have an optional boolean property to limit to standard
speed?

Thanks,
Mark.

>
> Optional properties :
> - i2c-sda-hold-time-ns : should contain the SDA hold time in nanoseconds.
> @@ -29,6 +31,7 @@ Example :
> reg = <0xf0000 0x1000>;
> interrupts = <11>;
> clock-frequency = <400000>;
> + speed-mode = <0>;
> };
>
> i2c@1120000 {
> --
> 1.7.9.5
>
> --
> To unsubscribe from this list: send the line "unsubscribe devicetree" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
>


\
 
 \ /
  Last update: 2014-08-20 11:41    [W:0.057 / U:0.780 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site