Messages in this thread | | | Subject | Re: [PATCH 2/2] watchdog: aspeed: Allow configuring for alternate boot | From | Eddie James <> | Date | Wed, 14 Mar 2018 14:53:13 -0500 |
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On 03/09/2018 04:06 PM, Guenter Roeck wrote: > On Fri, Mar 09, 2018 at 03:58:20PM -0600, Eddie James wrote: >> From: Milton Miller <miltonm@us.ibm.com> >> >> Allow the device tree to specify a watchdog to fallover to >> the alternate boot source. >> >> The aspeeed watchdog can set a latch directing flash chip select 0 to >> chip select 1, allowing boot from an alternate media if the watchdog >> is not reset in time. On the ast2400 bank 1 also goes to flash bank 1, >> while on the ast2500 the chip selects are swapped. >> >> Signed-off-by: Milton Miller <miltonm@us.ibm.com> >> Signed-off-by: Eddie James <eajames@linux.vnet.ibm.com> > This is already documented in the bindings document, so the property > should be ok. > > Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Thanks. On a related note, our system has need of a way to determine if it's currently booted from the alternate chip or not. It seems the only way to tell is to look at the ast2400/2500 watchdog timeout status register. We can add some debugfs to the aspeed driver I guess, but I wonder if this is a common enough situation that the watchdog core could use some debugfs or sysfs for providing that info?
Thanks, Eddie
> >> --- >> drivers/watchdog/aspeed_wdt.c | 3 +++ >> 1 file changed, 3 insertions(+) >> >> diff --git a/drivers/watchdog/aspeed_wdt.c b/drivers/watchdog/aspeed_wdt.c >> index d1987d6..f41d246 100644 >> --- a/drivers/watchdog/aspeed_wdt.c >> +++ b/drivers/watchdog/aspeed_wdt.c >> @@ -46,6 +46,7 @@ struct aspeed_wdt_config { >> #define WDT_RELOAD_VALUE 0x04 >> #define WDT_RESTART 0x08 >> #define WDT_CTRL 0x0C >> +#define WDT_CTRL_BOOT_SECONDARY BIT(7) >> #define WDT_CTRL_RESET_MODE_SOC (0x00 << 5) >> #define WDT_CTRL_RESET_MODE_FULL_CHIP (0x01 << 5) >> #define WDT_CTRL_RESET_MODE_ARM_CPU (0x10 << 5) >> @@ -245,6 +246,8 @@ static int aspeed_wdt_probe(struct platform_device *pdev) >> } >> if (of_property_read_bool(np, "aspeed,external-signal")) >> wdt->ctrl |= WDT_CTRL_WDT_EXT; >> + if (of_property_read_bool(np, "aspeed,alt-boot")) >> + wdt->ctrl |= WDT_CTRL_BOOT_SECONDARY; >> >> if (readl(wdt->base + WDT_CTRL) & WDT_CTRL_ENABLE) { >> /* >> -- >> 1.8.3.1 >>
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