On Fri Jan 16, 2026 at 9:26 PM JST, Daniel Almeida wrote:
> +cc Alex,
>
>
>>>> + 31:0 l2_pwractive_hi as u32, "Bitmap of L2 caches active (higher
>>>> 32 bits)";
>>>> +});
>>>> +
>>>> pub(crate) const MCU_CONTROL_ENABLE: u32 = 1;
>>>> pub(crate) const MCU_CONTROL_AUTO: u32 = 2;
>>>> pub(crate) const MCU_CONTROL_DISABLE: u32 = 0;
>>>> -pub(crate) const MCU_STATUS: Register<0x704> = Register;
>>>> +register!(McuControl @ 0x700, "Controls the execution state of the MCU
>>>> subsystem" {
>>>> + 1:0 req as u32, "Request state change";
>>>> +});
>>> Any reason why req is a u32 and not a u8? Same for some other places.
>>> And would it be an option to move the const MCU_CONTROL* to an ìmpl
>>> McuControl Same for STATUS below.
>>
>> Just fyi something like [1] builds for me.
>>
>> This is inspired by
>>
>> https://lore.kernel.org/rust-for-linux/[email protected]/
>>
>> Best regards
>>
>> Dirk
>>
>> [1]
>>
>> #[repr(u32)]
>> #[derive(Debug, Default, Clone, Copy, PartialEq)]
>> enum McuControl {
>> #[default]
>> Disable = 0,
>> Enable = 1,
>> Auto = 2,
>> }
>>
>> impl From<McuControl> for u8 {
>> fn from(ctrl: McuControl) -> Self {
>> ctrl as u8
>> }
>> }
>>
>> impl From<u8> for McuControl {
>> fn from(req: u8) -> Self {
>> match req & 0x3 {
>> 0 => McuControl::Disable,
>> 1 => McuControl::Enable,
>> 2 => McuControl::Auto,
>> _ => McuControl::Disable,
>> }
>> }
>> }
>>
>> register!(MCUCONTROL @ 0x700, "Controls the execution state of the MCU
>> subsystem" {
>> 1:0 req as u8 => McuControl, "Request state change";
>> });
>
> Alex, looking at the above, I wonder if a “as Foo” would be a good
> addition to the macro? That would then invoke a TryFrom implementation, i.e.:
>
>
> register!(MCUCONTROL @ 0x700, "Controls the execution state of the MCU
> subsystem" {
> 1:0 req as McuControl => McuControl, "Request state change";
> });
So the register macro that I will submit for the kernel crate will be
significantly different from the one in Nova. Expect something closer to
[1].
This means that fields won't need to have an explicit integer type
anymore (they will automatically use the corresponding `BoundedInt`
instead).
IIUC this will them behave as you expect.
[1]
https://lore.kernel.org/rust-for-linux/[email protected]/
