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

Ray Jui
2019-02-14T17:36:53Z

On 2/14/2019 6:16 AM, Rob Herring wrote:
> On Wed, Feb 13, 2019 at 4:06 PM Ray Jui <ray.jui@broadcom.com> wrote:
>>
>> Hi Rob,
>>
>> On 2/13/2019 1:16 PM, Rob Herring wrote:
>>> 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@broadcom.com>
>>>> Signed-off-by: Rayagonda Kokatanur <rayagonda.kokatanur@broadcom.com>
>>>> ---
>>>> .../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.
>>>
>> It's tied to the particular revision of the I2C controller, i.e., the
>> iProc NIC i2c controller does not have interrupt line wired. In this
>> case, the behavior is determined by the DT compatible string of the
>> iProc I2C device. I thought that it makes sense to now move the
>> 'interrupts' property to be under "Optional" than "Required" which is
>> basically what this change is.
>
> Okay, please put this detail into the commit msg.

Will do! Thanks.

>
> Rob
>