Hi Guillaume,
thank you for working on this!
On Tue, Jun 4, 2019 at 4:47 PM Guillaume La Roque <glaroque@xxxxxxxxxxxx> wrote:
>
> This adds the devicetree binding documentation for the Temperature
> Sensor found in the Amlogic Meson G12 SoCs.
> Currently only the G12A SoCs are supported.
so G12B is not supported (yet)?
> Signed-off-by: Guillaume La Roque <glaroque@xxxxxxxxxxxx>
> ---
> .../iio/temperature/amlogic,meson-tsensor.txt | 31 +++++++++++++++++++
> 1 file changed, 31 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/iio/temperature/amlogic,meson-tsensor.txt
>
> diff --git a/Documentation/devicetree/bindings/iio/temperature/amlogic,meson-tsensor.txt b/Documentation/devicetree/bindings/iio/temperature/amlogic,meson-tsensor.txt
> new file mode 100644
> index 000000000000..d064db0e9cac
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/iio/temperature/amlogic,meson-tsensor.txt
> @@ -0,0 +1,31 @@
> +* Amlogic Meson Temperature Sensor
> +
> +Required properties:
> +- compatible: depending on the SoC and the position of the sensor,
> + this should be one of:
> + - "amlogic,meson-g12a-cpu-tsensor" for the CPU G12A SoC sensor
> + - "amlogic,meson-g12a-ddr-tsensor" for the DDR G12A SoC sensor
> + followed by the common :
> + - "amlogic,meson-g12a-tsensor" for G12A SoC family
> +- reg: the physical base address and length of the registers
> +- interrupts: the interrupt indicating end of sampling
> +- clocks: phandle identifier for the reference clock of temperature sensor
> +- #io-channel-cells: must be 1, see ../iio-bindings.txt
have you considered using the thermal framework [0] instead of the iio
framework (see below)?
> +- amlogic,ao-secure: phandle to the ao-secure syscon
the driver has some "u_efuse_off" access. do we need to get some
calibration values from the AO syscon or can we also fetch it from the
eFuse? you can look at arch/arm/boot/dts/meson8.dtsi where I'm passing
the temperature sensor calibration data to the SAR ADC (there's no
dedicated temperature sensor IP block prior to G12A) while reading the
data from the eFuse
> +Optional properties:
> +- amlogic,critical-temperature: temperature value in milli degrees Celsius
> + to set automatic reboot on too high temperature
as far as I can tell the thermal framework supports multiple trip
points. I'm seeing this as a benefit because the hardware can raise
interrupts at four different temperatures (defined by the driver)
> +Example:
> + cpu_temp: temperature-sensor@ff634800 {
> + compatible = "amlogic,meson-g12a-cpu-tsensor",
> + "amlogic,meson-g12a-tsensor";
> + reg = <0x0 0xff634800 0x0 0x50>;
> + interrupts = <GIC_SPI 35 IRQ_TYPE_EDGE_RISING>;
> + clocks = <&clkc CLKID_TS>;
> + status = "okay";
as far as I know the dt-bindings should not have a status property in
the examples
Martin
