Re: [PATCH 3/3] arm64: dts: ti: k3-j7200-mcu-wakeup: Split fss node up

Kumar, Udit
2023-04-24T18:34:57Z

Hi Nishanth,

On 4/24/2023 11:06 PM, Nishanth Menon wrote:
> fss node claims to be entirely a syscon node, but it is really two
> parts of it - one a syscon that controls the hbmc mux and a simple bus
> where ospi, hbmc peripherals are located. So model it accordingly by
> splitting the node up and using ti,j721e-system-controller to describe
> the syscon
>
> Signed-off-by: Nishanth Menon <nm@ti.com>
> ---
> .../boot/dts/ti/k3-j7200-mcu-wakeup.dtsi | 21 +++++++++++++------
> 1 file changed, 15 insertions(+), 6 deletions(-)
>
> diff --git a/arch/arm64/boot/dts/ti/k3-j7200-mcu-wakeup.dtsi b/arch/arm64/boot/dts/ti/k3-j7200-mcu-wakeup.dtsi
> index b58a31371bf3..7653cb191be1 100644
> --- a/arch/arm64/boot/dts/ti/k3-j7200-mcu-wakeup.dtsi
> +++ b/arch/arm64/boot/dts/ti/k3-j7200-mcu-wakeup.dtsi
> @@ -338,18 +338,27 @@ mcu_spi2: spi@40320000 {
> status = "disabled";
> };
>
> - fss: syscon@47000000 {
> - compatible = "syscon", "simple-mfd";
> + hbmc_syscon: syscon@47000000 {
> + compatible = "ti,j721e-system-controller", "syscon", "simple-mfd";
> reg = <0x00 0x47000000 0x00 0x100>;

Description is given upto 0x78 register in TRM (Section 12.3.1.6 FSS
Registers)

Should we limit length to 0x78 ?

> - #address-cells = <2>;
> - #size-cells = <2>;
> - ranges;
> + #address-cells = <1>;
> + #size-cells = <1>;
> + ranges = <0x00 0x00 0x47000000 0x100>;
>
> - hbmc_mux: hbmc-mux {
> + hbmc_mux: mux-controller@4 {
> compatible = "mmio-mux";
> + reg = <0x4 0x2>;
> #mux-control-cells = <1>;
> mux-reg-masks = <0x4 0x2>; /* HBMC select */
> };
> + };
> +
> + fss: bus@47030000 {
> + compatible = "simple-bus";
> + reg = <0x0 0x47030000 0x0 0x100>;

Only registers upto address  0x47030008 has valid description in TRM

Section, 13.3.3.6.3 HyperBus Subsystem Registers

Please see, if we need to limit length to 8 instead of 256

> + #address-cells = <2>;
> + #size-cells = <2>;
> + ranges;
>
> hbmc: hyperbus@47034000 {
> compatible = "ti,am654-hbmc";