On Tue, Oct 15, 2024 at 04:15:40PM -0500, Rob Herring wrote: > On Tue, Oct 15, 2024 at 01:51:30PM +0300, Ciprian Costea wrote: > > From: Ciprian Marian Costea <ciprianmarian.costea@xxxxxxxxxxx> > > > > This patch adds the dt-bindings for NXP S32G2/S32G3 SoCs RTC driver. > > > > Co-developed-by: Bogdan-Gabriel Roman <bogdan-gabriel.roman@xxxxxxx> > > Signed-off-by: Bogdan-Gabriel Roman <bogdan-gabriel.roman@xxxxxxx> > > Co-developed-by: Ghennadi Procopciuc <ghennadi.procopciuc@xxxxxxx> > > Signed-off-by: Ghennadi Procopciuc <ghennadi.procopciuc@xxxxxxx> > > Signed-off-by: Ciprian Marian Costea <ciprianmarian.costea@xxxxxxxxxxx> > > --- > > .../devicetree/bindings/rtc/nxp,s32g-rtc.yaml | 102 ++++++++++++++++++ > > 1 file changed, 102 insertions(+) > > create mode 100644 Documentation/devicetree/bindings/rtc/nxp,s32g-rtc.yaml > > > > diff --git a/Documentation/devicetree/bindings/rtc/nxp,s32g-rtc.yaml b/Documentation/devicetree/bindings/rtc/nxp,s32g-rtc.yaml > > new file mode 100644 > > index 000000000000..3a77d4dd8f3d > > --- /dev/null > > +++ b/Documentation/devicetree/bindings/rtc/nxp,s32g-rtc.yaml > > @@ -0,0 +1,102 @@ > > +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause) > > +%YAML 1.2 > > +--- > > +$id: http://devicetree.org/schemas/rtc/nxp,s32g-rtc.yaml# > > +$schema: http://devicetree.org/meta-schemas/core.yaml# > > + > > +title: NXP S32G2/S32G3 Real Time Clock (RTC) > > + > > +maintainers: > > + - Bogdan Hamciuc <bogdan.hamciuc@xxxxxxx> > > + - Ciprian Marian Costea <ciprianmarian.costea@xxxxxxx> > > + > > +properties: > > + compatible: > > + oneOf: > > + - enum: > > + - nxp,s32g2-rtc > > + - items: > > + - const: nxp,s32g3-rtc > > + - const: nxp,s32g2-rtc > > + > > + reg: > > + maxItems: 1 > > + > > + interrupts: > > + maxItems: 1 > > + > > + "#clock-cells": > > + const: 1 > > + > > + clocks: > > + items: > > + - description: ipg clock drives the access to the > > + RTC iomapped registers > > + > > + clock-names: > > + items: > > + - const: ipg > > + > > + assigned-clocks: > > + minItems: 1 > > + items: > > + - description: Runtime clock source. It must be a clock > > + source for the RTC module. It will be disabled by hardware > > + during Standby/Suspend. > > + - description: Standby/Suspend clock source. It is optional > > + and can be used in case the RTC will continue ticking during > > + platform/system suspend. RTC hardware module contains a > > + hardware mux for clock source selection. > > If the RTC h/w contains a mux, then your mux inputs should be listed in > 'clocks', not here. > > > + > > + assigned-clock-parents: > > + description: List of phandles to each parent clock. > > + > > + assigned-clock-rates: > > + description: List of frequencies for RTC clock sources. > > + RTC module contains 2 hardware divisors which can be > > + enabled or not. Hence, available frequencies are the following > > + parent_freq, parent_freq / 512, parent_freq / 32 or > > + parent_freq / (512 * 32) > > In general, assigned-clocks* do not need to be documented and should > never be required. > > > + > > +required: > > + - compatible > > + - reg > > + - interrupts > > + - "#clock-cells" > > + - clocks > > + - clock-names > > + - assigned-clocks > > + - assigned-clock-parents > > + - assigned-clock-rates > > + > > +additionalProperties: false > > + > > +examples: > > + - | > > + #include <dt-bindings/interrupt-controller/arm-gic.h> > > + #include <dt-bindings/interrupt-controller/irq.h> > > + > > + rtc0: rtc@40060000 { > > + compatible = "nxp,s32g3-rtc", > > + "nxp,s32g2-rtc"; > > + reg = <0x40060000 0x1000>; > > + interrupts = <GIC_SPI 121 IRQ_TYPE_LEVEL_HIGH>; > > + #clock-cells = <1>; > > + clocks = <&clks 54>; > > + clock-names = "ipg"; > > + /* > > + * Configuration of default parent clocks. > > + * 'assigned-clocks' 0-3 IDs are Runtime clock sources > > + * 4-7 IDs are Suspend/Standby clock sources. > > + */ > > + assigned-clocks = <&rtc0 2>, <&rtc0 4>; > > That's weird... > > > + assigned-clock-parents = <&clks 56>, <&clks 55>; > > I'd expect these should be in 'clocks'. I don't think this node should > be a clock provider unless it provides a clock to something outside the > RTC. > > Looks like you are just using assigned-clocks to configure the clock mux > in the RTC. That's way over complicated. Just define a vendor specific > property with the mux settings. I just read v1 and got told use the clock framework... I disagree completely. Tons of h/w blocks have the ability to select (internal to the block) from multiple clock sources. Making the block a clock provider to itself is completely pointless and an overkill, and we *never* do that. Any display controller or audio interface has mutiple clock sources as just 2 examples. However, I don't see why you need the divider config in DT. Can't you figure out what divider you need based on input frequency? The output frequency should be fixed, right? Rob
