[PATCH v3 1/2] watchdog: imx2_wdt: add external reset support via 'ext-reset-output' dt prop

[shawnguo@kernel.org (Shawn Guo)]

On Tue, Jul 28, 2015 at 08:27:09AM -0700, Tim Harvey wrote:
> 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 '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: Lucas Stach <l.stach@pengutronix.de>
> Signed-off-by: Tim Harvey <tharvey@gateworks.com>

Acked-by: Shawn Guo <shawnguo@kernel.org>