On 5/2/25 3:17 PM, Kathiravan Thirumoorthy wrote:

When the system boots up after a watchdog reset, the EXPIRED_STATUS bit
in the WDT_STS register is cleared. To identify if the system was
restarted due to WDT expiry, XBL update the information in the IMEM region.
Update the driver to read the restart reason from IMEM and populate the
bootstatus accordingly.

With the CONFIG_WATCHDOG_SYSFS enabled, user can extract the information
as below:

cat /sys/devices/platform/soc@0/f410000.watchdog/watchdog/watchdog0/bootstatus
32

For backward compatibility, keep the EXPIRED_STATUS bit check. Add a new
function qcom_wdt_get_restart_reason() to read the restart reason from
IMEM.

Signed-off-by: Kathiravan Thirumoorthy <redacted>
---

[...]

+static int  qcom_wdt_get_restart_reason(struct qcom_wdt *wdt,
+					const struct qcom_wdt_match_data *data)
+{
+	struct regmap *imem;
+	unsigned int val;
+	int ret;
+
+	imem = syscon_regmap_lookup_by_compatible(data->imem_compatible);

Try syscon_regmap_lookup_by_phandle_args() and pass a phandle, see e.g.
drivers/phy/qualcomm/phy-qcom-qmp-pcie.c & phy@1bfc000 in x1e80100.dtsi

That way all platform specifics will live in the DT, requiring no
hardcode-y driver changes on similar platforms

Konrad