From mboxrd@z Thu Jan 1 00:00:00 1970 From: shawnguo@kernel.org (Shawn Guo) Date: Wed, 5 Aug 2015 21:01:16 +0800 Subject: [PATCH v3 1/2] watchdog: imx2_wdt: add external reset support via 'ext-reset-output' dt prop In-Reply-To: <1438097230-2653-2-git-send-email-tharvey@gateworks.com> References: <1433448960-9257-2-git-send-email-tharvey@gateworks.com> <1438097230-2653-1-git-send-email-tharvey@gateworks.com> <1438097230-2653-2-git-send-email-tharvey@gateworks.com> Message-ID: <20150805130115.GM12927@tiger> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org 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 > Signed-off-by: Tim Harvey Acked-by: Shawn Guo