dt-bindings: watchdog: sunxi: Add compatibles for R329
authorSamuel Holland <samuel@sholland.org>
Thu, 2 Sep 2021 22:57:48 +0000 (17:57 -0500)
committerWim Van Sebroeck <wim@linux-watchdog.org>
Tue, 26 Oct 2021 19:31:07 +0000 (21:31 +0200)
commit55f36df9ec4f6c53b6a06acfc4195e99bd9355fa
tree68cf67a3ce0c4f5cdac0558b512bea1f209a2aea
parentf01f0717928a7d38615c8ef5a72217bd63677e5b
dt-bindings: watchdog: sunxi: Add compatibles for R329

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@sholland.org>
Acked-by: Maxime Ripard <maxime@cerno.tech>
Reviewed-by: Rob Herring <robh@kernel.org>
Acked-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20210902225750.29313-2-samuel@sholland.org
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>
Documentation/devicetree/bindings/watchdog/allwinner,sun4i-a10-wdt.yaml