The i.MX6 watchdog can't be stopped once started. This means that
special hardware suspend needs to be configured when the device enters
low-power modes.
Usually i.MX devices have two bits which deal with this:
- WDZST bit disables the timer in "deeper" low power modes and
- WDW bit disables the timer in "WAIT" mode which corresponds with
Linux's "freeze" low-power mode.
WDZST bit support is already in place since 1a9c5efa576e ("watchdog: imx2_wdt: disable watchdog timer during low power mode").
WDW bit is not common for all imx2-wdt supported devices, therefore use
a new device-tree property "fsl,suspend-in-wait" which suspends the
watchdog in "WAIT" mode.
Andrej Picej (3):
watchdog: imx2_wdg: suspend watchdog in WAIT mode
dt-bindings: watchdog: fsl-imx: document suspend in wait mode
ARM: dts: imx6ul/ull: suspend i.MX6UL watchdog in wait mode
.../devicetree/bindings/watchdog/fsl-imx-wdt.yaml | 5 +++++
arch/arm/boot/dts/imx6ul-phytec-phycore-som.dtsi | 4 ++++
drivers/watchdog/imx2_wdt.c | 7 +++++++
3 files changed, 16 insertions(+)
--
2.25.1
