Re: [RFC PATCH 2/4] thermal: introduce device tree parser

[Stephen Warren <swarren@wwwdotorg.org>]

On 07/10/2013 12:48 AM, Wei Ni wrote:
> On 07/09/2013 10:00 PM, Eduardo Valentin wrote:
>> In order to be able to build thermal policies
>> based on generic sensors, like I2C device, that
>> can be places in different points on different boards,
>> there is a need to have a way to feed board dependent
>> data into the thermal framework.
>>
>> This patch introduces a thermal data parser for device
>> tree. The parsed data is used to build thermal zones
>> and thermal binding parameters. The output data
>> can then be used to deploy thermal policies.
>>
>> This patch adds also documentation regarding this
>> API and how to define define tree nodes to use
>> this infrastructure.
> 
> It looks good, with this infrastructure, we can add generic sensor
> driver into the thermal fw easily.
> 
> 
>> +
>> +Below is an example:
>> +thermal_zone {
>> +            type = "CPU";
>> +            mask = <0x03>; /* trips writability */
>> +            passive_delay = <250>; /* milliseconds */
>> +            polling_delay = <1000>; /* milliseconds */
>> +            governor = "step_wise";
>> +            trips {
>> +                    alert@100000{
>> +                            temperature = <100000>; /* milliCelsius */
>> +                            hysteresis = <0>; /* milliCelsius */
>> +                            type = <1>;
> 
> how about to use the trip type name directly, such as named as
> "passive-trip;", I think it's more readable. for example:
> trip0 {
> ....
> passive-trip;
> }
> trip1 {
> ....
> active-trip;
> }

You can always use the C pre-processor in DT now to define named constants:

include/dt-bindings/..../....h

	#define THERMAL_PASSIVE_TRIP 0
	#define THERMAL_ACTIVE_TRIP 1

*.dts:

	type = <THERMAL_PASSIVE_TRIP>;

Having a single 'property = value;' rather than n different Boolean
property names seems better, irrespective of whether value is an integer
or string; parsing and error-checking will be simpler.