diff options
| author | Tim Harvey <tharvey@gateworks.com> | 2016-04-01 18:16:43 +0300 |
|---|---|---|
| committer | Wim Van Sebroeck <wim@iguana.be> | 2016-05-14 10:36:38 +0300 |
| commit | bc677ff42e81bbf78308a7b66cf7b63b0f5c26b0 (patch) | |
| tree | dcef2c5380ca309e77a7f5a35fc0b16f0ab48415 /Documentation/devicetree/bindings/watchdog | |
| parent | ebbf677a3fb54fda56c58fc985c4617c215da6a0 (diff) | |
| download | linux-bc677ff42e81bbf78308a7b66cf7b63b0f5c26b0.tar.xz | |
watchdog: imx2_wdt: add external reset support via dt prop
The IMX6 watchdog supports assertion of a signal (WDOG_B) which
can be pinmux'd to an external pin. This is typically used for boards that
have PMIC's in control of the IMX6 power rails. In fact, failure to use
such an external reset on boards with external PMIC's can result in various
hangs due to the IMX6 not being fully reset [1] as well as the board failing
to reset because its PMIC has not been reset to provide adequate voltage for
the CPU when coming out of reset at 800Mhz.
This uses a new device-tree property 'fsl,ext-reset-output' to indicate the
board has such a reset and to cause the watchdog to be configured to assert
WDOG_B instead of an internal reset both on a watchdog timeout and in
system_restart.
[1] http://lists.infradead.org/pipermail/linux-arm-kernel/2015-March/333689.html
Cc: Fabio Estevam <festevam@gmail.com>
Cc: Lucas Stach <l.stach@pengutronix.de>
Cc: Stefan Roese <sr@denx.de>
Cc: Iain Paton <ipaton0@gmail.com>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Tim Harvey <tharvey@gateworks.com>
Reviewed-by: Lucas Stach <l.stach@pengutronix.de>
Acked-by: Shawn Guo <shawn.guo@linaro.org>
Tested-by: Akshay Bhat <akshay.bhat@timesys.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
Diffstat (limited to 'Documentation/devicetree/bindings/watchdog')
| -rw-r--r-- | Documentation/devicetree/bindings/watchdog/fsl-imx-wdt.txt | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/Documentation/devicetree/bindings/watchdog/fsl-imx-wdt.txt b/Documentation/devicetree/bindings/watchdog/fsl-imx-wdt.txt index 8dab6fd024aa..107280ef0025 100644 --- a/Documentation/devicetree/bindings/watchdog/fsl-imx-wdt.txt +++ b/Documentation/devicetree/bindings/watchdog/fsl-imx-wdt.txt @@ -5,10 +5,12 @@ Required properties: - reg : Should contain WDT registers location and length - interrupts : Should contain WDT interrupt -Optional property: +Optional properties: - big-endian: If present the watchdog device's registers are implemented in big endian mode, otherwise in native mode(same with CPU), for more detail please see: Documentation/devicetree/bindings/regmap/regmap.txt. +- fsl,ext-reset-output: If present the watchdog device is configured to + assert its external reset (WDOG_B) instead of issuing a software reset. Examples: |