From: Niklas Söderlund <niklas.soderlund+renesas@xxxxxxxxxxxx> Hi all, The series adds thermal support to Renesas R-Car Gen3 SoCs. It's tested on Salvator-X H3 and M3-W SoC. Wolfram asked me to have a look at the comments for v4 and to try and rework the temperature formulas to work with only ints and if it worked out resend the series. I have reworked code in 2/5 but kept Wolfram as the author and added my SoB, hope this is OK. Reworking the formulas involved moving from s64 to int as the data type used to store coefficients used in decimal scaled fixed point calculations. By examining the largest values which could be produced in these calculations a factor of 100 is the maximum scaling which is possible and still fit inside an int, previously with s64 the scaling was 1000. Reducing the decimal scaling also reduces the accuracy of the calculations. In my tests this was hardly noticeable as the granularity of the reported temperature to user-space is 0.5C, comparing the value reported in the s64 vs int implementation only differ very slightly when it rounded the value to the next 0.5C level. However the formulas used to calculate the coefficients are not documented and none obvious (at lest not to me) so given different initial values to calculate the coefficients the error might become larger. Therefore I would like to ask Morimoto-san and/or Khiem to provide or proxy testing of this less accurate formula and feedback if it's OK, let me know if there is anything I can do to help out. Changes since v4: - Use only 32 bit ints to convert from register value to temperature. - Merge and simplify temp calculation functions. - Document what I known about the temprature conversion formulas. - Add new patch 5/5 which fixes a waring printout caused by trying to get temp before hardware is ready on r8a7795. - Fixed a few checkpatch warnings. Niklas Söderlund (1): thermal: rcar_gen3_thermal: Add delay in .thermal_init on r8a7795 Wolfram Sang (4): thermal: rcar_gen3_thermal: Document the R-Car Gen3 thermal: rcar_gen3_thermal: Add R-Car Gen3 thermal driver arm64: dts: r8a7795: Add R-Car Gen3 thermal support arm64: dts: r8a7796: Add R-Car Gen3 thermal support .../bindings/thermal/rcar-gen3-thermal.txt | 56 ++++ arch/arm64/boot/dts/renesas/r8a7795.dtsi | 58 ++++ arch/arm64/boot/dts/renesas/r8a7796.dtsi | 58 ++++ drivers/thermal/Kconfig | 9 + drivers/thermal/Makefile | 1 + drivers/thermal/rcar_gen3_thermal.c | 330 +++++++++++++++++++++ 6 files changed, 512 insertions(+) create mode 100644 Documentation/devicetree/bindings/thermal/rcar-gen3-thermal.txt create mode 100644 drivers/thermal/rcar_gen3_thermal.c -- 2.10.2
