Re: [PATCH v4 3/8] dt-bindings: i2c: iproc: make 'interrupts' optional

From: Rob Herring
Date: Wed Feb 13 2019 - 16:16:57 EST


On Mon, Feb 04, 2019 at 03:15:49PM -0800, Ray Jui wrote:
> In prep for the introduction of polling mode into the driver, update the
> binding document to make the 'interrupts' property optional
>
> Signed-off-by: Ray Jui <ray.jui@xxxxxxxxxxxx>
> Signed-off-by: Rayagonda Kokatanur <rayagonda.kokatanur@xxxxxxxxxxxx>
> ---
> .../devicetree/bindings/i2c/brcm,iproc-i2c.txt | 10 +++++++---
> 1 file changed, 7 insertions(+), 3 deletions(-)
>
> diff --git a/Documentation/devicetree/bindings/i2c/brcm,iproc-i2c.txt b/Documentation/devicetree/bindings/i2c/brcm,iproc-i2c.txt
> index 81f982ccca31..d3a3620b1f06 100644
> --- a/Documentation/devicetree/bindings/i2c/brcm,iproc-i2c.txt
> +++ b/Documentation/devicetree/bindings/i2c/brcm,iproc-i2c.txt
> @@ -9,9 +9,6 @@ Required properties:
> Define the base and range of the I/O address space that contain the iProc
> I2C controller registers
>
> -- interrupts:
> - Should contain the I2C interrupt
> -
> - clock-frequency:
> This is the I2C bus clock. Need to be either 100000 or 400000
>
> @@ -21,6 +18,13 @@ Required properties:
> - #size-cells:
> Always 0
>
> +Optional properties:
> +
> +- interrupts:
> + Should contain the I2C interrupt. If unspecified, driver will fall back to
> + polling mode

What determines when you want to use polling mode? I'm not sure DT
is the best way to control this unless it's really a property of
the h/w. Driver behavior is really outside the scope of the DT. u-boot
would use polling even if an interrupt is specified, for example.

Rob