On Wed, May 21, 2025 at 03:45:03PM +0900, Alexandre Courbot wrote:
> Some registers (notably scratch registers) don't have a definitive
> purpose, but need to be interpreted differently depending on context.
>
> Expand the register!() macro to support a syntax indicating that a
> register type should be at the same offset as another one, but under a
> different name, and with different fields and documentation.
>
> Signed-off-by: Alexandre Courbot <acour...@nvidia.com>
> ---
> drivers/gpu/nova-core/regs/macros.rs | 40
> ++++++++++++++++++++++++++++++++++--
> 1 file changed, 38 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/nova-core/regs/macros.rs
> b/drivers/gpu/nova-core/regs/macros.rs
> index
> 7cd013f3c90bbd8ca437d4072cae8f11d7946fcd..64dda1d4d93d3c7022ef02b6f6fb81b58e90dd44
> 100644
> --- a/drivers/gpu/nova-core/regs/macros.rs
> +++ b/drivers/gpu/nova-core/regs/macros.rs
> @@ -71,6 +71,20 @@
> /// pr_info!("CPU CTL: {:#x}", cpuctl);
> /// cpuctl.set_start(true).write(&bar, CPU_BASE);
> /// ```
> +///
> +/// It is also possible to create a alias register by using the `=> PARENT`
> syntax. This is useful
> +/// for cases where a register's interpretation depends on the context:
> +///
> +/// ```no_run
> +/// register!(SCRATCH_0 @ 0x0000100, "Scratch register 0" {
> +/// 31:0 value as u32, "Raw value";
> +///
> +/// register!(SCRATCH_0_BOOT_STATUS => SCRATCH_0, "Boot status of the
> firmware" {
NIT: I'd put the arrow the other way around, i.e. SCRATCH_0_BOOT_STATUS is
derived from SCRATCH_0, not the other way around.
