Hi Tim, > 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@xxxxxxxxx> > Cc: Lucas Stach <l.stach@xxxxxxxxxxxxxx> > Cc: Stefan Roese <sr@xxxxxxx> > Cc: Iain Paton <ipaton0@xxxxxxxxx> > Cc: Sascha Hauer <s.hauer@xxxxxxxxxxxxxx> > Cc: Akshay Bhat <akshay.bhat@xxxxxxxxxxx> > Cc: Guenter Roeck <linux@xxxxxxxxxxxx> > Signed-off-by: Tim Harvey <tharvey@xxxxxxxxxxxxx> > Reviewed-by: Lucas Stach <l.stach@xxxxxxxxxxxxxx> > Acked-by: Shawn Guo <shawn.guo@xxxxxxxxxx> > --- > v5: > - rename property to 'fsl,ext-reset-output' > v4: > - change Property to Properties in documentation > v3: > - mandate use of 'either' internal or external reset but not both > simultaneously > v2: > - rename property to 'ext-reset-output' based on ML feedback > - simplify setting SRS bit if external-reset > - update comments and commit msg > > Signed-off-by: Tim Harvey <tharvey@xxxxxxxxxxxxx> > --- > .../devicetree/bindings/watchdog/fsl-imx-wdt.txt | 4 +++- > drivers/watchdog/imx2_wdt.c | 19 +++++++++++++++++-- > 2 files changed, 20 insertions(+), 3 deletions(-) > This patch has been added to linux-watchdog-next. Kind regards, Wim. -- To unsubscribe from this list: send the line "unsubscribe linux-watchdog" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
