Re: [PATCH V3 1/2] thermal: max77620: Add DT binding doc for thermal driver

[Keerthy <a0393675@ti.com>]

On Tuesday 07 June 2016 12:08 PM, Laxman Dewangan wrote:
>
> On Tuesday 07 June 2016 09:25 AM, Keerthy wrote:
>>
>>
>> On Monday 06 June 2016 05:14 PM, Laxman Dewangan wrote:
>>> Maxim Semiconductor MAX77620 supports alarm interrupts when
>>> its die temperature crosses 120C and 140C. These threshold
>>> temperatures are not configurable.
>>>
>>> Add DT binding document to details out the DT property related
>>> to MAX77620 thermal functionality.
>>>
>>> Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
>>> ---
>>>   .../bindings/thermal/thermal-max77620.txt          | 64
>>> ++++++++++++++++++++++
>>>   1 file changed, 64 insertions(+)
>>>   create mode 100644
>>> Documentation/devicetree/bindings/thermal/thermal-max77620.txt
>>>
>>> diff --git
>>> a/Documentation/devicetree/bindings/thermal/thermal-max77620.txt
>>> b/Documentation/devicetree/bindings/thermal/thermal-max77620.txt
>>> new file mode 100644
>>> index 0000000..5a500d5
>>> --- /dev/null
>>> +++ b/Documentation/devicetree/bindings/thermal/thermal-max77620.txt
>>> @@ -0,0 +1,64 @@
>>> +Thermal driver for MAX77620 Power management IC from Maxim
>>> Semiconductor.
>>> +
>>> +Maxim Semiconductor MAX77620 supports alarm interrupts when its
>>> +die temperature crosses 120C and 140C. These threshold temperatures
>>> +are not configurable. Device does not provide the real temperature
>>> +of die other than just indicating whether temperature is above or
>>> +below threshold level.
>>> +
>>> +Required properties:
>>> +-------------------
>>> +#thermal-sensor-cells:    Please refer
>>> <devicetree/bindings/thermal/thermal.txt>
>>> +            for more details.
>>> +            The value must be 0.
>>> +
>>> +For more details, please refer generic thermal DT binding document
>>> +<devicetree/bindings/thermal/thermal.txt>.
>>> +
>>> +Please refer <devicetree/bindings/mfd/max77620.txt> for mfd DT binding
>>> +document for the MAX77620.
>>> +
>>> +Example:
>>> +--------
>>> +#include <dt-bindings/mfd/max77620.h>
>>> +#include <dt-bindings/thermal/thermal.h>
>>> +...
>>> +
>>> +i2c@7000d000 {
>>> +    spmic: max77620@3c {
>>> +        compatible = "maxim,max77620";
>>> +        :::::
>>> +        #thermal-sensor-cells = <0>;
>>> +        :::
>>> +    };
>>> +};
>>> +
>>> +cool_dev: cool-dev {
>>> +    compatible = "cooling-dev";
>>> +    #cooling-cells = <2>;
>>> +};
>>> +
>>> +thermal-zones {
>>> +    PMIC-Die {
>>> +        polling-delay = <0>;
>>> +        polling-delay-passive = <0>;
>>> +        thermal-sensors = <&spmic>;
>>> +
>>> +        trips {
>>> +            die_temp_thresh: hot-die {
>>> +                temperature = <120000>;
>>> +                type = "active";
>>> +                hysteresis = <0>;
>>> +            };
>>> +        };
>>
>> What about 140C? Isn't that a critical trip point?
>
> Yes, it is there and it can be populated/extended on the same way and
> handled.
>
> This is just an example.

Yes i understand that. My question was more w.r.t different types of 
critical points. As i can see 120C is an active trip point.

140C will be a critical trip point and system will have to be shutdown 
right? IMHO you can add that to the example as well since its pretty 
different than the above active trip point.

- Keerthy

>
>
>>
>>> +
>>> +        cooling-maps {
>>> +            map0 {
>>> +                trip = <&die_temp_thresh>;
>>> +                cooling-device = <&cool_dev THERMAL_NO_LIMIT
>>> +                          THERMAL_NO_LIMIT>;
>>> +                contribution = <100>;
>>> +            };
>>> +        };
>>> +    };
>>> +};
>>>
>