On Tue, Apr 07, 2015 at 11:46:22AM +0800, Xinwei Kong wrote: > > > On 2015/4/6 22:03, Matt Porter wrote: > > On Tue, Mar 31, 2015 at 02:59:21PM +0800, Xinwei Kong wrote: > >> From: kongxinwei <[email protected]> > >> > >> This adds documentation of device tree bindings for the > >> thermal sensor controller of hi6220 SoC. > >> > >> Signed-off-by: Leo Yan <[email protected]> > >> Signed-off-by: kongxinwei <[email protected]> > >> --- > >> .../bindings/thermal/hisilicon-thermal.txt | 45 > >> ++++++++++++++++++++++ > >> 1 file changed, 45 insertions(+) > >> create mode 100644 > >> Documentation/devicetree/bindings/thermal/hisilicon-thermal.txt > >> > >> diff --git > >> a/Documentation/devicetree/bindings/thermal/hisilicon-thermal.txt > >> b/Documentation/devicetree/bindings/thermal/hisilicon-thermal.txt > >> new file mode 100644 > >> index 0000000..ceb6e2e > >> --- /dev/null > >> +++ b/Documentation/devicetree/bindings/thermal/hisilicon-thermal.txt > >> @@ -0,0 +1,45 @@ > >> +* Hisilicon Thermal > >> + > >> +This driver is for hi6220 SoC which contain 4 thermal sensor. > >> + > >> + 1. sensor 0: local sensor; > >> + 2. sensor 1: remote sensor for ACPU cluster 1; > >> + 3. sensor 2: remote sensor for ACPU cluster 2; > >> + 4. sensor 3: remote sensor for GPU. > >> + > >> +Every sensor use one child node to represent it, so thermal sensor include > >> +parent node and four child node. The parent node describe common feature > >> and > >> +child node describe private feature for thermal sensor; > >> + > >> +** Required properties : > >> + > >> +- compatible: "hisilicon,tsensor". > >> +- reg: physical base address of thermal sensor and length of memory mapped > >> + region. > >> +- interrupt: The interrupt number to the cpu. Defines the interrupt used > >> + by SOCTHERM. > >> +- clock-names: Input clock name, should be 'thermal_clk'. > >> +- clocks: phandles for clock specified in "clock-names" property. > >> +- #thermal-sensor-cells: Should be 1. See ./thermal.txt for a description. > >> + > >> +** Required properties for child nodes : > >> + > >> +- hisilicon,tsensor-id: the index of thermal sensor and use it to > >> distinguish > >> + thermal sensor. For example: <0> stands for local sensor; <1> stands for > >> + acpu1 sensor; > > > > Please show an example illustrating why this property is needed. The > > example below doesn't show any per sensor properties aside from the > > sensor id. Other bindings with a similar sub-sensor hardware design like > > tegra-soctherm and rockchip-thermal don't have a need for a vendor > > specific property like this. Their drivers simply iterate over an id > > index during thermal sensor registration. > > > > -Matt > > > Thermal Ip of hisilicon SoC can get four module temperature--local sensor, > ACPU0 > sensor, ACPU1 sensor and gpu sensor. In order to use these sensors, this > driver > will make use of sensor id to distinguish sensor in using process. > > These four sensors only get one sensor temperature at the same times. Because > these sensor commonly use the same register by setting diff value to enable > one > sensor. howerver, sensor id is key flag for these diff sensor modules. > > If deleting sensor id, this driver will define some value which set diff > sensor > regitser and it difficult to understand sensor register operation.
The above still do not explain why you need a specific property.
Could you please check
Documentation/devicetree/bindings/thermal/thermal.txt file?
There are several examples there on how to define DT nodes for the exact
case you describe above.
>
> Thanks
> Xinwei
>
> >> +
> >> +Example :
> >> +
> >> + tsensor: tsensor@0,f7030700 {
> >> + compatible = "hisilicon,tsensor";
> >> + reg = <0x0 0xf7030700 0x0 0x1000>;
> >> + interrupts = <0 7 0x4>;
> >> + clocks = <&clock_sys HI6220_TSENSOR_CLK>;
> >> + clock-names = "thermal_clk";
> >> + #thermal-sensor-cells = <1>;
> >> +
> >> + local_sensor {
> >> + hisilicon,tsensor-id = <0>;
> >> + }
> >> + .......
> >> + }
> >> --
> >> 1.9.1
> >>
> >>
> >>
> >> _______________________________________________
> >> linux-arm-kernel mailing list
> >> [email protected]
> >> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
> >
> > .
> >
>
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