Re: [PATCH 1/2] dt-bindings: i2c: Add MediaTek i2c AC timing binding

From: Wolfram Sang
Date: Wed Jun 26 2019 - 09:39:47 EST


Hi,

On Tue, Jun 11, 2019 at 04:11:54PM +0800, Qii Wang wrote:
> Add i2c AC timing binding to binding file. It can give the AC
> timing parameters to meet I2C specification at different speed.
>
> Signed-off-by: Qii Wang <qii.wang@xxxxxxxxxxxx>

I think this is a too specific 1:1 mapping of your register set into DT
world. We already have these generic parameters:

- clock-frequency
frequency of bus clock in Hz.

- i2c-scl-falling-time-ns
Number of nanoseconds the SCL signal takes to fall; t(f) in the I2C
specification.

- i2c-scl-internal-delay-ns
Number of nanoseconds the IP core additionally needs to setup SCL.

- i2c-scl-rising-time-ns
Number of nanoseconds the SCL signal takes to rise; t(r) in the I2C
specification.

- i2c-sda-falling-time-ns
Number of nanoseconds the SDA signal takes to fall; t(f) in the I2C
specification.

(check Documentation/devicetree/bindings/i2c/i2c.txt)

Can't you use those to derive your values from that? Which ones are you missing
if not?

Regards,

Wolfram

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