Set WDT_CLEAR_TIMEOUT_AND_BOOT_CODE_SELECTION into WDT_CLEAR_TIMEOUT_STATUS to clear out boot code source and re-enable access to the primary SPI flash chip while booted via wdt2 from the alternate chip.
AST2400 datasheet says: "In the 2nd flash booting mode, all the address mapping to CS0# would be re-directed to CS1#. And CS0# is not accessable under this mode. To access CS0#, firmware should clear the 2nd boot mode register in the WDT2 status register WDT30.bit[1]." Signed-off-by: Ivan Mikhaylov <[email protected]> --- drivers/watchdog/aspeed_wdt.c | 30 ++++++++++++++++++++++++++++++ 1 file changed, 30 insertions(+) diff --git a/drivers/watchdog/aspeed_wdt.c b/drivers/watchdog/aspeed_wdt.c index cc71861e033a..858e62f1c7ba 100644 --- a/drivers/watchdog/aspeed_wdt.c +++ b/drivers/watchdog/aspeed_wdt.c @@ -53,6 +53,8 @@ MODULE_DEVICE_TABLE(of, aspeed_wdt_of_table); #define WDT_CTRL_ENABLE BIT(0) #define WDT_TIMEOUT_STATUS 0x10 #define WDT_TIMEOUT_STATUS_BOOT_SECONDARY BIT(1) +#define WDT_CLEAR_TIMEOUT_STATUS 0x14 +#define WDT_CLEAR_TIMEOUT_AND_BOOT_CODE_SELECTION BIT(0) /* * WDT_RESET_WIDTH controls the characteristics of the external pulse (if @@ -165,6 +167,29 @@ static int aspeed_wdt_restart(struct watchdog_device *wdd, return 0; } +static ssize_t access_cs0_store(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t size) +{ + struct aspeed_wdt *wdt = dev_get_drvdata(dev); + + if (unlikely(!wdt)) + return -ENODEV; + + writel(WDT_CLEAR_TIMEOUT_AND_BOOT_CODE_SELECTION, + wdt->base + WDT_CLEAR_TIMEOUT_STATUS); + wdt->wdd.bootstatus |= WDIOF_EXTERN1; + + return size; +} +static DEVICE_ATTR_WO(access_cs0); + +static struct attribute *bswitch_attrs[] = { + &dev_attr_access_cs0.attr, + NULL +}; +ATTRIBUTE_GROUPS(bswitch); + static const struct watchdog_ops aspeed_wdt_ops = { .start = aspeed_wdt_start, .stop = aspeed_wdt_stop, @@ -223,6 +248,9 @@ static int aspeed_wdt_probe(struct platform_device *pdev) wdt->ctrl = WDT_CTRL_1MHZ_CLK; + if (of_property_read_bool(np, "aspeed,alt-boot")) + wdt->wdd.groups = bswitch_groups; + /* * Control reset on a per-device basis to ensure the * host is not affected by a BMC reboot @@ -309,6 +337,8 @@ static int aspeed_wdt_probe(struct platform_device *pdev) if (status & WDT_TIMEOUT_STATUS_BOOT_SECONDARY) wdt->wdd.bootstatus = WDIOF_CARDRESET; + dev_set_drvdata(dev, wdt); + return devm_watchdog_register_device(dev, &wdt->wdd); } -- 2.20.1
