[PATCH v2 0/2] Add cofficients to the TH1520 PVT

[PATCH v2 0/2] Add cofficients to the TH1520 PVT

[Icenowy Zheng]

This patchset tries to add PVT cofficients from the T-Head TH1520 user
manual to the corresponding DTSI file.

The v1 revision of this patchset is called "Initial thermal management
for Lichee Pi 4A board", however the thermal zone and cooling related
parts are already added to the DT as part of the TH1520 PWM patchset.

Icenowy Zheng (2):
  dt-bindings: hwmon: moortec,mr75203: adapt multipleOf for T-Head
    TH1520
  riscv: dts: thead: th1520: add coefficients to the PVT node

 Documentation/devicetree/bindings/hwmon/moortec,mr75203.yaml | 4 ++--
 arch/riscv/boot/dts/thead/th1520.dtsi                        | 4 ++++
 2 files changed, 6 insertions(+), 2 deletions(-)

-- 
2.52.0

[PATCH v2 1/2] dt-bindings: hwmon: moortec,mr75203: adapt multipleOf for T-Head TH1520

[Icenowy Zheng]

The G and J coefficients provided by T-Head TH1520 manual (which calls
them A and C coefficients and calls H coefficient in the binding as B)
has the 1/100 degree Celsius bit (the values are 42.74 and -0.16
correspondingly), however the binding currently only allows cofficients
as precise as 100 milli-Celsius (1/10 degree Celsius).

Change the multipleOf value of these two cofficients to 10 (in the unit
of milli-Celsius) to satisfy the need of TH1520.

Signed-off-by: Icenowy Zheng <zhengxingda@iscas.ac.cn>
---
New patch in v2.

 Documentation/devicetree/bindings/hwmon/moortec,mr75203.yaml | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/Documentation/devicetree/bindings/hwmon/moortec,mr75203.yaml b/Documentation/devicetree/bindings/hwmon/moortec,mr75203.yaml
index 56db2292f062d..7d57c2934a8a1 100644
--- a/Documentation/devicetree/bindings/hwmon/moortec,mr75203.yaml
+++ b/Documentation/devicetree/bindings/hwmon/moortec,mr75203.yaml
@@ -105,7 +105,7 @@ properties:
       G coefficient for temperature equation.
       Default for series 5 = 60000
       Default for series 6 = 57400
-    multipleOf: 100
+    multipleOf: 10
     minimum: 1000
     $ref: /schemas/types.yaml#/definitions/uint32
 
@@ -131,7 +131,7 @@ properties:
       J coefficient for temperature equation.
       Default for series 5 = -100
       Default for series 6 = 0
-    multipleOf: 100
+    multipleOf: 10
     maximum: 0
     $ref: /schemas/types.yaml#/definitions/int32
 
-- 
2.52.0

Re: [PATCH v2 1/2] dt-bindings: hwmon: moortec,mr75203: adapt multipleOf for T-Head TH1520

[Drew Fustini]

On Thu, Mar 05, 2026 at 10:40:43PM +0800, Icenowy Zheng wrote:
> The G and J coefficients provided by T-Head TH1520 manual (which calls
> them A and C coefficients and calls H coefficient in the binding as B)
> has the 1/100 degree Celsius bit (the values are 42.74 and -0.16
> correspondingly), however the binding currently only allows cofficients
> as precise as 100 milli-Celsius (1/10 degree Celsius).
> 
> Change the multipleOf value of these two cofficients to 10 (in the unit
> of milli-Celsius) to satisfy the need of TH1520.
> 
> Signed-off-by: Icenowy Zheng <zhengxingda@iscas.ac.cn>
> ---
> New patch in v2.
> 
>  Documentation/devicetree/bindings/hwmon/moortec,mr75203.yaml | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/Documentation/devicetree/bindings/hwmon/moortec,mr75203.yaml b/Documentation/devicetree/bindings/hwmon/moortec,mr75203.yaml
> index 56db2292f062d..7d57c2934a8a1 100644
> --- a/Documentation/devicetree/bindings/hwmon/moortec,mr75203.yaml
> +++ b/Documentation/devicetree/bindings/hwmon/moortec,mr75203.yaml
> @@ -105,7 +105,7 @@ properties:
>        G coefficient for temperature equation.
>        Default for series 5 = 60000
>        Default for series 6 = 57400
> -    multipleOf: 100
> +    multipleOf: 10
>      minimum: 1000
>      $ref: /schemas/types.yaml#/definitions/uint32
>  
> @@ -131,7 +131,7 @@ properties:
>        J coefficient for temperature equation.
>        Default for series 5 = -100
>        Default for series 6 = 0
> -    multipleOf: 100
> +    multipleOf: 10
>      maximum: 0
>      $ref: /schemas/types.yaml#/definitions/int32
>  
> -- 
> 2.52.0
> 

I am wondering if there is any backwards compatibility issue but there
are no other users of this compatible in mainline other than th1520.
There is also the precendent 030d2a0ce5dc ("dt-bindings: hwmon:
moortec,mr75203: fix multipleOf for coefficients") having change the
property. I suppose it is a not a problem unless other people on the
list raise an objection.

Thanks,
Drew

Re: [PATCH v2 1/2] dt-bindings: hwmon: moortec,mr75203: adapt multipleOf for T-Head TH1520

[Icenowy Zheng]

在 2026-03-05四的 10:36 -0800，Drew Fustini写道：
> On Thu, Mar 05, 2026 at 10:40:43PM +0800, Icenowy Zheng wrote:
> > The G and J coefficients provided by T-Head TH1520 manual (which
> > calls
> > them A and C coefficients and calls H coefficient in the binding as
> > B)
> > has the 1/100 degree Celsius bit (the values are 42.74 and -0.16
> > correspondingly), however the binding currently only allows
> > cofficients
> > as precise as 100 milli-Celsius (1/10 degree Celsius).
> > 
> > Change the multipleOf value of these two cofficients to 10 (in the
> > unit
> > of milli-Celsius) to satisfy the need of TH1520.
> > 
> > Signed-off-by: Icenowy Zheng <zhengxingda@iscas.ac.cn>
> > ---
> > New patch in v2.
> > 
> >  Documentation/devicetree/bindings/hwmon/moortec,mr75203.yaml | 4
> > ++--
> >  1 file changed, 2 insertions(+), 2 deletions(-)
> > 
> > diff --git
> > a/Documentation/devicetree/bindings/hwmon/moortec,mr75203.yaml
> > b/Documentation/devicetree/bindings/hwmon/moortec,mr75203.yaml
> > index 56db2292f062d..7d57c2934a8a1 100644
> > --- a/Documentation/devicetree/bindings/hwmon/moortec,mr75203.yaml
> > +++ b/Documentation/devicetree/bindings/hwmon/moortec,mr75203.yaml
> > @@ -105,7 +105,7 @@ properties:
> >        G coefficient for temperature equation.
> >        Default for series 5 = 60000
> >        Default for series 6 = 57400
> > -    multipleOf: 100
> > +    multipleOf: 10
> >      minimum: 1000
> >      $ref: /schemas/types.yaml#/definitions/uint32
> >  
> > @@ -131,7 +131,7 @@ properties:
> >        J coefficient for temperature equation.
> >        Default for series 5 = -100
> >        Default for series 6 = 0
> > -    multipleOf: 100
> > +    multipleOf: 10
> >      maximum: 0
> >      $ref: /schemas/types.yaml#/definitions/int32
> >  
> > -- 
> > 2.52.0
> > 
> 
> I am wondering if there is any backwards compatibility issue but
> there
> are no other users of this compatible in mainline other than th1520.
> There is also the precendent 030d2a0ce5dc ("dt-bindings: hwmon:
> moortec,mr75203: fix multipleOf for coefficients") having change the
> property. I suppose it is a not a problem unless other people on the
> list raise an objection.

Well mathematically any number that is a multiple of 100 is a multiple
of 10?

So theoretically there should be no compatibility issue.

Thanks
Icenowy

> 
> Thanks,
> Drew

Re: [PATCH v2 1/2] dt-bindings: hwmon: moortec,mr75203: adapt multipleOf for T-Head TH1520

[Conor Dooley]

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On Fri, Mar 06, 2026 at 02:39:40AM +0800, Icenowy Zheng wrote:
> 在 2026-03-05四的 10:36 -0800，Drew Fustini写道：
> > On Thu, Mar 05, 2026 at 10:40:43PM +0800, Icenowy Zheng wrote:
> > > The G and J coefficients provided by T-Head TH1520 manual (which
> > > calls
> > > them A and C coefficients and calls H coefficient in the binding as
> > > B)
> > > has the 1/100 degree Celsius bit (the values are 42.74 and -0.16
> > > correspondingly), however the binding currently only allows
> > > cofficients
> > > as precise as 100 milli-Celsius (1/10 degree Celsius).
> > > 
> > > Change the multipleOf value of these two cofficients to 10 (in the
> > > unit
> > > of milli-Celsius) to satisfy the need of TH1520.
> > > 
> > > Signed-off-by: Icenowy Zheng <zhengxingda@iscas.ac.cn>
> > > ---
> > > New patch in v2.
> > > 
> > >  Documentation/devicetree/bindings/hwmon/moortec,mr75203.yaml | 4
> > > ++--
> > >  1 file changed, 2 insertions(+), 2 deletions(-)
> > > 
> > > diff --git
> > > a/Documentation/devicetree/bindings/hwmon/moortec,mr75203.yaml
> > > b/Documentation/devicetree/bindings/hwmon/moortec,mr75203.yaml
> > > index 56db2292f062d..7d57c2934a8a1 100644
> > > --- a/Documentation/devicetree/bindings/hwmon/moortec,mr75203.yaml
> > > +++ b/Documentation/devicetree/bindings/hwmon/moortec,mr75203.yaml
> > > @@ -105,7 +105,7 @@ properties:
> > >        G coefficient for temperature equation.
> > >        Default for series 5 = 60000
> > >        Default for series 6 = 57400
> > > -    multipleOf: 100
> > > +    multipleOf: 10
> > >      minimum: 1000
> > >      $ref: /schemas/types.yaml#/definitions/uint32
> > >  
> > > @@ -131,7 +131,7 @@ properties:
> > >        J coefficient for temperature equation.
> > >        Default for series 5 = -100
> > >        Default for series 6 = 0
> > > -    multipleOf: 100
> > > +    multipleOf: 10
> > >      maximum: 0
> > >      $ref: /schemas/types.yaml#/definitions/int32
> > >  
> > > -- 
> > > 2.52.0
> > > 
> > 
> > I am wondering if there is any backwards compatibility issue but
> > there
> > are no other users of this compatible in mainline other than th1520.
> > There is also the precendent 030d2a0ce5dc ("dt-bindings: hwmon:
> > moortec,mr75203: fix multipleOf for coefficients") having change the
> > property. I suppose it is a not a problem unless other people on the
> > list raise an objection.
> 
> Well mathematically any number that is a multiple of 100 is a multiple
> of 10?
> 
> So theoretically there should be no compatibility issue.

Ye I don't think this is likely worth worrying about. The restrictions
exist in these kinds of cases to tell users they're doing the wrong
thing and using a value the hardware doesn't support, the driver almost
certainly will never care and just "blindly" use the number without
doing any validation, so as long as the multipleOf matches the
capability of the hardware you're okay.

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Re: [PATCH v2 1/2] dt-bindings: hwmon: moortec,mr75203: adapt multipleOf for T-Head TH1520

[Guenter Roeck]

On Thu, Mar 05, 2026 at 10:40:43PM +0800, Icenowy Zheng wrote:
> The G and J coefficients provided by T-Head TH1520 manual (which calls
> them A and C coefficients and calls H coefficient in the binding as B)
> has the 1/100 degree Celsius bit (the values are 42.74 and -0.16
> correspondingly), however the binding currently only allows cofficients
> as precise as 100 milli-Celsius (1/10 degree Celsius).
> 
> Change the multipleOf value of these two cofficients to 10 (in the unit
> of milli-Celsius) to satisfy the need of TH1520.
> 
AI feedback:

This isn't a bug, but there are a few typos in the commit message:
- "cofficients" should be "coefficients"
- "correspondingly" should be "respectively"
- "has" should be "have" (referring to "The G and J coefficients")
Additionally, "has the 1/100 degree Celsius bit" is slightly confusing and
might be clearer as "have 1/100 degree Celsius precision".

Please fix.

Thanks,
Guenter

Re: [PATCH v2 1/2] dt-bindings: hwmon: moortec,mr75203: adapt multipleOf for T-Head TH1520

[Drew Fustini]

On Thu, Mar 05, 2026 at 10:40:43PM +0800, Icenowy Zheng wrote:
> The G and J coefficients provided by T-Head TH1520 manual (which calls
> them A and C coefficients and calls H coefficient in the binding as B)
> has the 1/100 degree Celsius bit (the values are 42.74 and -0.16
> correspondingly), however the binding currently only allows cofficients
> as precise as 100 milli-Celsius (1/10 degree Celsius).
> 
> Change the multipleOf value of these two cofficients to 10 (in the unit
> of milli-Celsius) to satisfy the need of TH1520.
> 
> Signed-off-by: Icenowy Zheng <zhengxingda@iscas.ac.cn>
> ---
> New patch in v2.
> 
>  Documentation/devicetree/bindings/hwmon/moortec,mr75203.yaml | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/Documentation/devicetree/bindings/hwmon/moortec,mr75203.yaml b/Documentation/devicetree/bindings/hwmon/moortec,mr75203.yaml
> index 56db2292f062d..7d57c2934a8a1 100644
> --- a/Documentation/devicetree/bindings/hwmon/moortec,mr75203.yaml
> +++ b/Documentation/devicetree/bindings/hwmon/moortec,mr75203.yaml
> @@ -105,7 +105,7 @@ properties:
>        G coefficient for temperature equation.
>        Default for series 5 = 60000
>        Default for series 6 = 57400
> -    multipleOf: 100
> +    multipleOf: 10
>      minimum: 1000
>      $ref: /schemas/types.yaml#/definitions/uint32
>  
> @@ -131,7 +131,7 @@ properties:
>        J coefficient for temperature equation.
>        Default for series 5 = -100
>        Default for series 6 = 0
> -    multipleOf: 100
> +    multipleOf: 10
>      maximum: 0
>      $ref: /schemas/types.yaml#/definitions/int32
>  
> -- 
> 2.52.0
> 

Reviewed-by: Drew Fustini <fustini@kernel.org>

[PATCH v2 2/2] riscv: dts: thead: th1520: add coefficients to the PVT node

[Icenowy Zheng]

The manual of TH1520 contains a set of coefficients a little different
to the driver default ones.

Add them to the device tree node of PVT.

Signed-off-by: Icenowy Zheng <uwu@icenowy.me>
Signed-off-by: Icenowy Zheng <zhengxingda@iscas.ac.cn>
---
No changes in v2.

 arch/riscv/boot/dts/thead/th1520.dtsi | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/arch/riscv/boot/dts/thead/th1520.dtsi b/arch/riscv/boot/dts/thead/th1520.dtsi
index bd5d33840884e..2160c8b6c2261 100644
--- a/arch/riscv/boot/dts/thead/th1520.dtsi
+++ b/arch/riscv/boot/dts/thead/th1520.dtsi
@@ -753,6 +753,10 @@ pvt: pvt@fffff4e000 {
 			reg-names = "common", "ts", "pd", "vm";
 			clocks = <&aonsys_clk>;
 			#thermal-sensor-cells = <1>;
+			moortec,ts-coeff-g = <42740>;
+			moortec,ts-coeff-h = <220500>;
+			moortec,ts-coeff-j = <(-160)>;
+			moortec,ts-coeff-cal5 = <4094>;
 		};
 
 		gpio@fffff52000 {
-- 
2.52.0

Re: [PATCH v2 2/2] riscv: dts: thead: th1520: add coefficients to the PVT node

[Drew Fustini]

On Thu, Mar 05, 2026 at 10:40:44PM +0800, Icenowy Zheng wrote:
> The manual of TH1520 contains a set of coefficients a little different
> to the driver default ones.
> 
> Add them to the device tree node of PVT.
> 
> Signed-off-by: Icenowy Zheng <uwu@icenowy.me>
> Signed-off-by: Icenowy Zheng <zhengxingda@iscas.ac.cn>
> ---
> No changes in v2.
> 
>  arch/riscv/boot/dts/thead/th1520.dtsi | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/arch/riscv/boot/dts/thead/th1520.dtsi b/arch/riscv/boot/dts/thead/th1520.dtsi
> index bd5d33840884e..2160c8b6c2261 100644
> --- a/arch/riscv/boot/dts/thead/th1520.dtsi
> +++ b/arch/riscv/boot/dts/thead/th1520.dtsi
> @@ -753,6 +753,10 @@ pvt: pvt@fffff4e000 {
>  			reg-names = "common", "ts", "pd", "vm";
>  			clocks = <&aonsys_clk>;
>  			#thermal-sensor-cells = <1>;
> +			moortec,ts-coeff-g = <42740>;
> +			moortec,ts-coeff-h = <220500>;
> +			moortec,ts-coeff-j = <(-160)>;
> +			moortec,ts-coeff-cal5 = <4094>;
>  		};
>  
>  		gpio@fffff52000 {
> -- 
> 2.52.0
> 

Thanks for the patch. This matches the information in "Section 15.3.4
Temperature Sensor" on page 866 in the TH1520 System User Manul.

Reviewed-by: Drew Fustini <fustini@kernel.org>