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 <i.mikhaylov@xxxxxxxxx>
---
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
