Re: [PATCH] dt-bindings: clock: agilex: mark mpu_l2ram_clk deprecated

[Krzysztof Kozlowski <krzk@kernel.org>]

On Mon, Jul 27, 2026 at 05:49:26PM +0800, genevieve.chan@altera.com wrote:
> From: Genevieve Chan <genevieve.chan@altera.com>
> 
> Preliminary documentation referred to mpu_l2ram_clk, but that clock is
> now mpu_ccu_clk and is already represented by AGILEX_MPU_CCU_CLK.
> Keep AGILEX_MPU_L2RAM_CLK as a legacy ABI-preserved ID (do not use in
> new DTs) and mark clock ID 42 as reserved/unused so it is not reused,
> keeping all existing clock IDs stable for DT ABI compatibility.
> 
> Fixes: 6b3c59780ed3 ("dt-bindings: documentation: add clock bindings information for Agilex")
> Cc: stable@vger.kernel.org # 5.8+
> Signed-off-by: Genevieve Chan <genevieve.chan@altera.com>
> ---
>  include/dt-bindings/clock/agilex-clock.h | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/include/dt-bindings/clock/agilex-clock.h b/include/dt-bindings/clock/agilex-clock.h
> index 06feca07e08e..de7a58a06651 100644
> --- a/include/dt-bindings/clock/agilex-clock.h
> +++ b/include/dt-bindings/clock/agilex-clock.h
> @@ -44,6 +44,7 @@
>  
>  /* Gate clocks */
>  #define AGILEX_MPU_CLK			30
> +/* Legacy ABI ID; do not use in new DTs, use AGILEX_MPU_CCU_CLK */
>  #define AGILEX_MPU_L2RAM_CLK		31
>  #define AGILEX_MPU_PERIPH_CLK		32
>  #define AGILEX_L4_MAIN_CLK		33
> @@ -55,6 +56,7 @@
>  #define AGILEX_CS_TIMER_CLK		39
>  #define AGILEX_S2F_USER0_CLK		40
>  #define AGILEX_EMAC0_CLK		41
> +/* 42 - reserved/unused */

How IDs can be reserved? These are implemented by drivers (abstract IDs
not used by hardware), so how driver could reserve it?

Best regards,
Krzysztof