Re: [PATCH 1/3] dt-bindings: i2c: add optional mul-value property to binding

Uwe Kleine-König
2019-04-30T06:38:33Z

On Tue, Apr 30, 2019 at 12:32:40PM +0800, Chuanhua Han wrote:
> NXP Layerscape SoC have up to three MUL options available for all
> divider values, we choice of MUL determines the internal monitor rate
> of the I2C bus (SCL and SDA signals):
> A lower MUL value results in a higher sampling rate of the I2C signals.
> A higher MUL value results in a lower sampling rate of the I2C signals.
>
> So in Optional properties we added our custom mul-value property in the
> binding to select which mul option for the device tree i2c controller
> node.
>
> Signed-off-by: Chuanhua Han <chuanhua.han@nxp.com>
> ---
> Documentation/devicetree/bindings/i2c/i2c-imx.txt | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/Documentation/devicetree/bindings/i2c/i2c-imx.txt b/Documentation/devicetree/bindings/i2c/i2c-imx.txt
> index b967544590e8..ba8e7b7b3fa8 100644
> --- a/Documentation/devicetree/bindings/i2c/i2c-imx.txt
> +++ b/Documentation/devicetree/bindings/i2c/i2c-imx.txt
> @@ -18,6 +18,9 @@ Optional properties:
> - sda-gpios: specify the gpio related to SDA pin
> - pinctrl: add extra pinctrl to configure i2c pins to gpio function for i2c
> bus recovery, call it "gpio" state
> +- mul-value: NXP Layerscape SoC have up to three MUL options available for
> +all I2C divider values, it describes which MUL we choose to use for the driver,
> +the values should be 1,2,4.

Indention is broken.

I wonder why this needs to be configurable on a per-machine/device
level. What is the trade-off?

Best regards
Uwe

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