From: Biju Das <biju.das.jz@bp.renesas.com>

Some reset lines must remain deasserted at all times after boot, as
asserting them would disable critical system functionality with no
owning driver to restore them. This mirrors the existing crit_mod_clks
mechanism which protects critical module clocks from being disabled.

On RZ/G2L family SoCs, DMA reset to be deasseted for routing some
peripheral interrupts to CPU.

After a suspend/resume cycle, critical module clocks may be left
disabled as the hardware state is not automatically restored. Unlike
regular clocks which are re-enabled by their respective drivers, critical
clocks (CLK_IS_CRITICAL) have no owning driver to restore them, so the
CPG driver must take responsibility for re-enabling them on resume.

Biju Das (3):
  clk: renesas: rzg2l-cpg: Add support for critical resets
  clk: renesas: r9a07g04{3,4}/r9a08g045-cpg: Add critical reset entries
  clk: renesas: rzg2l-cpg: Re-enable critical module clocks during
    resume

 drivers/clk/renesas/r9a07g043-cpg.c |  8 +++
 drivers/clk/renesas/r9a07g044-cpg.c | 13 +++++
 drivers/clk/renesas/r9a08g045-cpg.c |  9 ++++
 drivers/clk/renesas/rzg2l-cpg.c     | 75 ++++++++++++++++++++++++++++-
 drivers/clk/renesas/rzg2l-cpg.h     |  7 +++
 5 files changed, 111 insertions(+), 1 deletion(-)

-- 
2.43.0

Hi Biju,

On Fri, 6 Mar 2026 at 14:42, Biju <biju.das.au@gmail.com> wrote:
> From: Biju Das <biju.das.jz@bp.renesas.com>
>
> Some reset lines must remain deasserted at all times after boot, as
> asserting them would disable critical system functionality with no
> owning driver to restore them. This mirrors the existing crit_mod_clks
> mechanism which protects critical module clocks from being disabled.
>
> On RZ/G2L family SoCs, DMA reset to be deasseted for routing some
> peripheral interrupts to CPU.
>
> After a suspend/resume cycle, critical module clocks may be left
> disabled as the hardware state is not automatically restored. Unlike
> regular clocks which are re-enabled by their respective drivers, critical
> clocks (CLK_IS_CRITICAL) have no owning driver to restore them, so the
> CPG driver must take responsibility for re-enabling them on resume.
>
> Biju Das (3):
>   clk: renesas: rzg2l-cpg: Add support for critical resets
>   clk: renesas: r9a07g04{3,4}/r9a08g045-cpg: Add critical reset entries
>   clk: renesas: rzg2l-cpg: Re-enable critical module clocks during
>     resume

I assume this series supersedes "[PATCH] clk: renesas: rzg2l: Drop DMA
driver dependency for system boot"[1]?

[1] https://lore.kernel.org/20260130143456.256813-1-biju.das.jz@bp.renesas.com

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds