Re: [PATCH v3 1/3] dt-bindings: watchdog: sunxi: Add compatibles for R329
From: Rob Herring
Date: Fri Sep 03 2021 - 12:07:51 EST
On Thu, 02 Sep 2021 17:57:48 -0500, Samuel Holland wrote:
> On existing SoCs, the watchdog has a single clock input: HOSC (OSC24M)
> divided by 750. However, starting with R329, LOSC (OSC32k) is added as
> an alternative clock source, with a bit to switch between them.
>
> Since 24 MHz / 750 == 32 kHz, not 32.768 kHz, the hardware adjusts the
> cycle counts to keep the timeouts independent of the clock source. This
> keeps the programming interface backward-compatible.
>
> Furthermore, the R329 has two watchdogs: one for use by the ARM CPUs
> at 0x20000a0, and a second one for use by the DSPs at 0x7020400. The
> first of these adds two more new registers, to allow software to
> immediately assert the SoC reset signal. Add an additional "-reset"
> suffix to signify the presence of this feature.
>
> Signed-off-by: Samuel Holland <samuel@xxxxxxxxxxxx>
> ---
> Changes v2 to v3:
> - Add else case
> - Add additional allwinner,sun50i-r329-wdt-reset compatible
> Changes v1 to v2:
> - Switch clock-names from enum to const
> - Add descriptions to "clocks" items
>
> .../watchdog/allwinner,sun4i-a10-wdt.yaml | 42 ++++++++++++++++++-
> 1 file changed, 41 insertions(+), 1 deletion(-)
>
Reviewed-by: Rob Herring <robh@xxxxxxxxxx>