watchdog: aspeed: Allow configuring for alternate boot

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.

Also clear the secondary boot bit during the machine restart operation.
Otherwise, the system will switch to the alternate boot after every
reboot, which is not desired.

Signed-off-by: Milton Miller <miltonm@us.ibm.com>
Signed-off-by: Eddie James <eajames@linux.vnet.ibm.com>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
This commit is contained in:
Milton Miller 2018-03-15 11:02:06 -05:00 committed by Wim Van Sebroeck
parent 975b7f0fe6
commit 6ffa340221

View File

@ -46,6 +46,7 @@ MODULE_DEVICE_TABLE(of, aspeed_wdt_of_table);
#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)
@ -158,6 +159,7 @@ static int aspeed_wdt_restart(struct watchdog_device *wdd,
{
struct aspeed_wdt *wdt = to_aspeed_wdt(wdd);
wdt->ctrl &= ~WDT_CTRL_BOOT_SECONDARY;
aspeed_wdt_enable(wdt, 128 * WDT_RATE_1MHZ / 1000);
mdelay(1000);
@ -242,6 +244,8 @@ 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) {
/*