Re: [PATCH v2 4/4] arm64: dts: amlogic: Add S7D Reset Controller

[Martin Blumenstingl]

On Tue, Dec 23, 2025 at 6:37 AM Xianwei Zhao via B4 Relay
<devnull+xianwei.zhao.amlogic.com@xxxxxxxxxx> wrote:
[...]
> +#define RESET_BRG_A55_PIPE0            166
For S7 (without D suffix) this is called RESET_BRG_A53_PIPE0 - which
one is correct (looking at amlogic-s7.dtsi and amlogic-s7d.dtsi
possibly A55 is correct)?
unrelated side-note while I was checking amlogic-s7.dtsi and
amlogic-s7d.dtsi: why do we have D/I and L2 caches defined for one but
not the other?

[...]
> +#define RESET_BRG_NIC_EMMC             183
> +/*                                     164     */
this needs to state 184

On a related side-note: while reviewing this patch I'm wondering how
S7 differs from S7D.
Is S7 a cut-down version of the S7D SoC (e.g. some - possibly faulty -
IP blocks fused off), is S7D a slightly updated version (like rev 2.0)
of S7, ...?
What I'm missing is a "big picture" (for older SoCs we typically had
some SBC vendor publish a datasheet - for these newer SoCs there's no
public datasheets).

That said, I think the approach chosen for the reset controller (copy
& paste, except 13 reset lines) is fine because there seem to be
actual differences in the reset lines. For other
drivers/implementations this approach would likely get very hard to
review/maintain (e.g. if we end up with a 3000 line driver and there's
only 250 lines difference between the two SoCs).


Best regards,
Martin