Re: [PATCH v4 2/9] dt-bindings: i2c: add bindings for i2c analog and digital filter
From: Peter Rosin
Date: Mon Sep 02 2019 - 06:49:15 EST
On 2019-09-02 12:12, Eugen.Hristev@xxxxxxxxxxxxx wrote:
> From: Eugen Hristev <eugen.hristev@xxxxxxxxxxxxx>
> Some i2c controllers have a built-in digital or analog filter.
> This is specifically required depending on the hardware PCB/board.
> Some controllers also allow specifying the maximum width of the
> spikes that can be filtered. The width length can be specified in nanoseconds.
> Signed-off-by: Eugen Hristev <eugen.hristev@xxxxxxxxxxxxx>
> Documentation/devicetree/bindings/i2c/i2c.txt | 11 +++++++++++
> 1 file changed, 11 insertions(+)
> diff --git a/Documentation/devicetree/bindings/i2c/i2c.txt b/Documentation/devicetree/bindings/i2c/i2c.txt
> index 44efafd..8dbff67 100644
> --- a/Documentation/devicetree/bindings/i2c/i2c.txt
> +++ b/Documentation/devicetree/bindings/i2c/i2c.txt
> @@ -55,6 +55,17 @@ wants to support one of the below features, it should adapt the bindings below.
> Number of nanoseconds the SDA signal takes to fall; t(f) in the I2C
> +- i2c-analog-filter
> + Enable analog filter for i2c lines.
> +- i2c-digital-filter
> + Enable digital filter for i2c lines.
> +- i2c-filter-width-ns
> + Width of spikes which can be filtered by either digital or analog
> + filters (i2c-analog-filtr or i2c-digital-filtr). This width is specified
filtr -> filter (two instances)
What if you want/need to have different bandwidth for the digital and analog
filters? After all, this is a generic binding...
> + in nanoseconds.
> - interrupts
> interrupts used by the device.