On Mon, Apr 12, 2021 at 6:03 PM Johan Jonker <jbx6244@xxxxxxxxx> wrote: > > On 4/12/21 5:15 AM, Chen-Yu Tsai wrote: > > On Sun, Apr 11, 2021 at 9:11 PM Johan Jonker <jbx6244@xxxxxxxxx> wrote: > >> > >> A test with the command below gives this error: > >> > >> /arch/arm/boot/dts/rv1108-evb.dt.yaml: > >> pwm@10280000: 'interrupts' does not match any of the regexes: > >> 'pinctrl-[0-9]+' > >> > >> "interrupts" is an undocumented property, so remove them > >> from pwm nodes in rv1108.dtsi. > >> > >> make ARCH=arm dtbs_check > >> DT_SCHEMA_FILES=Documentation/devicetree/bindings/pwm/pwm-rockchip.yaml > >> > >> Signed-off-by: Johan Jonker <jbx6244@xxxxxxxxx> > > > > Given that the interrupts were specified, meaning they are wired up in hardware, > > shouldn't the solution be to add the interrupts property to the binding instead? > > > > After all, the device tree describes the actual hardware, not just what the > > implementations need. > > > > ChenYu > > > > Hi, > > The question of what to do with it was asked in version 1, but no answer > was given, so I made a proposal. > The device tree description should be complete, but also as lean as > possible. If someone manages to sneak in undocumented properties without > reason then the ultimate consequence should be removal I think. > > Not sure about the (missing?) rv1108 TRM, but for rk3328 the interrupt > is used for: > > PWM_INTSTS 0x0040 W 0x00000000 Interrupt Status Register > Channel Interrupt Polarity Flag > This bit is used in capture mode in order to identify the > transition of the input waveform when interrupt is generated. > Channel Interrupt Status > Interrupt generated > > PWM_INT_EN 0x0044 W 0x00000000 Interrupt Enable Register > Channel Interrupt Enable > > Is there any current realistic use/setup for it to convince rob+dt this > should be added to pwm-rockchip.yaml? Well, the PWM core has capture support, and pwm-sti implements it with interrupt support, so I guess there's at least a legitimate case for adding that to the binding. Whether someone has an actual use case for it and adds code to implement it is another story. > The rk3328 interrupt rkpwm_int seems shared between channels, but only > included to pwm3. What is the proper way for that? I guess the bigger question is why was the PWM controller split into four device nodes, instead of just one encompassing the whole block. Now we'd have to introduce a new binding to support capture mode and interrupts. In that case I agree with dropping the interrupts for now, as it just won't fit. But I would add this additional information to the commit message. Regards ChenYu
