STM32n6: driver: Clock - enabling MSI clock

[brendena]

Summary

Currently there's no way from the device tree to enable the MSI clock.

List of clocks can be found here.

zephyr/dts/arm/st/n6/stm32n6.dtsi

Lines 65 to 249 in e4f97dd

	clocks {
	clk_hse: clk-hse {
	#clock-cells = <0>;
	compatible = "st,stm32n6-hse-clock";
	status = "disabled";
	};
	clk_hsi: clk-hsi {
	#clock-cells = <0>;
	compatible = "st,stm32h7-hsi-clock";
	clock-frequency = <DT_FREQ_M(64)>;
	status = "disabled";
	};
	clk_lse: clk-lse {
	#clock-cells = <0>;
	compatible = "st,stm32-lse-clock";
	clock-frequency = <32768>;
	driving-capability = <2>;
	status = "disabled";
	};
	clk_lsi: clk-lsi {
	#clock-cells = <0>;
	compatible = "fixed-clock";
	clock-frequency = <DT_FREQ_K(32)>;
	status = "disabled";
	};
	pll1: pll: pll {
	#clock-cells = <0>;
	compatible = "st,stm32n6-pll-clock";
	status = "disabled";
	};
	pll2: pll2 {
	#clock-cells = <0>;
	compatible = "st,stm32n6-pll-clock";
	status = "disabled";
	};
	pll3: pll3 {
	#clock-cells = <0>;
	compatible = "st,stm32n6-pll-clock";
	status = "disabled";
	};
	pll4: pll4 {
	#clock-cells = <0>;
	compatible = "st,stm32n6-pll-clock";
	status = "disabled";
	};
	cpusw: cpusw {
	#clock-cells = <0>;
	compatible = "st,stm32n6-cpu-clock-mux", "st,stm32-clock-mux";
	status = "disabled";
	};
	perck: perck {
	#clock-cells = <0>;
	compatible = "st,stm32-clock-mux";
	status = "disabled";
	};
	ic1: ic1 {
	#clock-cells = <0>;
	compatible = "st,stm32n6-ic-clock-mux";
	status = "disabled";
	};
	ic2: ic2 {
	#clock-cells = <0>;
	compatible = "st,stm32n6-ic-clock-mux";
	status = "disabled";
	};
	ic3: ic3 {
	#clock-cells = <0>;
	compatible = "st,stm32n6-ic-clock-mux";
	status = "disabled";
	};
	ic4: ic4 {
	#clock-cells = <0>;
	compatible = "st,stm32n6-ic-clock-mux";
	status = "disabled";
	};
	ic5: ic5 {
	#clock-cells = <0>;
	compatible = "st,stm32n6-ic-clock-mux";
	status = "disabled";
	};
	ic6: ic6 {
	#clock-cells = <0>;
	compatible = "st,stm32n6-ic-clock-mux";
	status = "disabled";
	};
	ic7: ic7 {
	#clock-cells = <0>;
	compatible = "st,stm32n6-ic-clock-mux";
	status = "disabled";
	};
	ic8: ic8 {
	#clock-cells = <0>;
	compatible = "st,stm32n6-ic-clock-mux";
	status = "disabled";
	};
	ic9: ic9 {
	#clock-cells = <0>;
	compatible = "st,stm32n6-ic-clock-mux";
	status = "disabled";
	};
	ic10: ic10 {
	#clock-cells = <0>;
	compatible = "st,stm32n6-ic-clock-mux";
	status = "disabled";
	};
	ic11: ic11 {
	#clock-cells = <0>;
	compatible = "st,stm32n6-ic-clock-mux";
	status = "disabled";
	};
	ic12: ic12 {
	#clock-cells = <0>;
	compatible = "st,stm32n6-ic-clock-mux";
	status = "disabled";
	};
	ic13: ic13 {
	#clock-cells = <0>;
	compatible = "st,stm32n6-ic-clock-mux";
	status = "disabled";
	};
	ic14: ic14 {
	#clock-cells = <0>;
	compatible = "st,stm32n6-ic-clock-mux";
	status = "disabled";
	};
	ic15: ic15 {
	#clock-cells = <0>;
	compatible = "st,stm32n6-ic-clock-mux";
	status = "disabled";
	};
	ic16: ic16 {
	#clock-cells = <0>;
	compatible = "st,stm32n6-ic-clock-mux";
	status = "disabled";
	};
	ic17: ic17 {
	#clock-cells = <0>;
	compatible = "st,stm32n6-ic-clock-mux";
	status = "disabled";
	};
	ic18: ic18 {
	#clock-cells = <0>;
	compatible = "st,stm32n6-ic-clock-mux";
	status = "disabled";
	};
	ic19: ic19 {
	#clock-cells = <0>;
	compatible = "st,stm32n6-ic-clock-mux";
	status = "disabled";
	};
	ic20: ic20 {
	#clock-cells = <0>;
	compatible = "st,stm32n6-ic-clock-mux";
	status = "disabled";
	};
	};

Describe the solution you'd like

I looked at stm32U5 and the stm32L1 for reference on how they added support for MSI clock enabling.

So it's like the u5 because it has a custom clock configuration, but it's also like the L1 in that it only has one MSI clock not MSIK and MSIS clock.

So a mix of both approaches would work.

• Custom stm32n6-msi driver
• The configuration in the clock_stm32_ll_n6.c file

Alternatives

No response

Additional Context

No response

[brendena]

Pull request for this.

#108575