[PATCH] firmware: qcom: scm: Detect Gunyah by Qualcomm's hypervisor UID too

[Stanislav Aleksandrov]

qcom_scm registers the Gunyah watchdog only when the hypervisor reports
the Gunyah UID. On the Samsung Galaxy XR (Qualcomm Halliday), Gunyah
reports Qualcomm's hypervisor UID instead, so gunyah_wdt never probes
there, and no other watchdog is available.

Accept Qualcomm's hypervisor UID too. gunyah_wdt still checks for the
watchdog: where the hypervisor reports this UID without it, the probe
returns -ENODEV.

Signed-off-by: Stanislav Aleksandrov <lightofmysoul@xxxxxxxxx>
---
This is part of the bring-up of the Qualcomm Halliday SoC (SXR2250P)
in the Samsung Galaxy XR. The DT changes follow in a separate series.

This work was made together with Claude, ChatGPT and Gemini.
Reviewed and tested on my Galaxy XR: gunyah_wdt binds, and the watchdog
resets a hung system.
---
 drivers/firmware/qcom/qcom_scm.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/firmware/qcom/qcom_scm.c b/drivers/firmware/qcom/qcom_scm.c
index 43e250faea75..559865139c46 100644
--- a/drivers/firmware/qcom/qcom_scm.c
+++ b/drivers/firmware/qcom/qcom_scm.c
@@ -2434,6 +2434,10 @@ static void qcom_scm_gunyah_wdt_init(struct qcom_scm *scm)
 	static const uuid_t gunyah_uuid = UUID_INIT(0xc1d58fcd, 0xa453, 0x5fdb,
 						    0x92, 0x65, 0xce, 0x36,
 						    0x67, 0x3d, 0x5f, 0x14);
+	/* Some Qualcomm Gunyah builds report Qualcomm's hypervisor UID */
+	static const uuid_t qc_hyp_uuid = UUID_INIT(0xbd54bd19, 0x1b57, 0x370b,
+						    0x9b, 0x60, 0x6f, 0x94,
+						    0xe6, 0x9d, 0x53, 0x54);
 	static const char * const of_wdt_compatible[] = {
 		"qcom,kpss-wdt",
 		"arm,sbsa-gwdt",
@@ -2441,7 +2445,8 @@ static void qcom_scm_gunyah_wdt_init(struct qcom_scm *scm)
 
 	/* Bail out if we are not running under Gunyah */
 	if (!IS_ENABLED(CONFIG_HAVE_ARM_SMCCC_DISCOVERY) ||
-	    !arm_smccc_hypervisor_has_uuid(&gunyah_uuid))
+	    (!arm_smccc_hypervisor_has_uuid(&gunyah_uuid) &&
+	     !arm_smccc_hypervisor_has_uuid(&qc_hyp_uuid)))
 		return;
 
 	/*

---
base-commit: 6628e7d4c6b25c8d18f1345e3a20d21829aae7e4
change-id: 20261108-qcom-scm-gunyah-uid-ba58c10dfb66

Best regards,
--  
Stanislav Aleksandrov <lightofmysoul@xxxxxxxxx>