Re: [PATCHv2 2/4] arm/dts: omap5-evm: Add tmp102 sensor support

[Benoit Cousson <b-cousson@ti.com>]

Hi Felipe,

On 08/14/2012 11:59 AM, Felipe Balbi wrote:
> On Tue, Aug 14, 2012 at 11:56:45AM +0200, Benoit Cousson wrote:
>> On 08/13/2012 12:05 PM, Sourav Poddar wrote:
>>> Add tmp102 temperature sensor data in omap5 evm dts file.
>>>
>>> Tested on omap5430 evm with 3.5 custom kernel.
>>>
>>> Cc: Benoit Cousson <b-cousson@ti.com>
>>> Cc: Felipe Balbi <balbi@ti.com>
>>> Cc: Santosh Shilimkar <santosh.shilimkar@ti.com>
>>> Acked-by: Felipe Balbi <balbi@ti.com>
>>> Signed-off-by: Sourav Poddar <sourav.poddar@ti.com>
>>> ---
>>>  arch/arm/boot/dts/omap5-evm.dts |    9 +++++++++
>>>  1 files changed, 9 insertions(+), 0 deletions(-)
>>>
>>> diff --git a/arch/arm/boot/dts/omap5-evm.dts b/arch/arm/boot/dts/omap5-evm.dts
>>> index 200c39a..45a8aeb 100644
>>> --- a/arch/arm/boot/dts/omap5-evm.dts
>>> +++ b/arch/arm/boot/dts/omap5-evm.dts
>>> @@ -18,3 +18,12 @@
>>>  		reg = <0x80000000 0x40000000>; /* 1 GB */
>>>  	};
>>>  };
>>> +
>>> +&i2c4 {
>>> +	clock-frequency = <400000>;
>>
>> Have you checked if we cannot run at faster speed? Reducing the speed
>> will impact every devices on the bus.
>> It might be needed, I just wanted to be sure.
>>
>> You should maybe just add a small comment to explain what the device is
>> doing with potentially a link to the HW spec if available.
>>
>> The same comments are applicable to the bmp085 patch.
> 
> that sort of information should be placed on
> Documentation/devicetree/bindings/*/$device.txt, right ? Why should we
> replicate it on all dts files ? 

Well in that case, this is not part of the binding documentation, but
that can be a good idea to update the documentation indeed.

> Besides, there are only two such entries
> on all ARM DTS files. Do we really want to make dts files bigger with
> links to documentation which can even be moved at any time to other
> location by the manufacturer's choice ? Will anyone actually keep track
> of such links to make sure they aren't broken ? And even if someone does
> track those links, do we really want to keep sending such patches for
> the dts files ?

A little bit of comment and documentation will never hurt anybody and
will not have any impact on the DTB size. If that can save us some time
to avoid googling to know what device we are taking about, it is already
better than nothing.

Regards,
Benoit