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 <kong.kongxinwei@xxxxxxxxxxxxx>
> >>
> >> This adds documentation of device tree bindings for the
> >> thermal sensor controller of hi6220 SoC.
> >>
> >> Signed-off-by: Leo Yan <leo.yan@xxxxxxxxxx>
> >> Signed-off-by: kongxinwei <kong.kongxinwei@xxxxxxxxxxxxx>
> >> ---
> >> .../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
> >>
> >>
> >>
> >> _______________________________________________
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> >> linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
> >> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
> >
> > .
> >
>
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