@@ -46,6 +46,8 @@ static int smcwd_call(struct watchdog_device *wdd, enum smcwd_call call,
return -ENODEV;
if (res->a0 == PSCI_RET_INVALID_PARAMS)
return -EINVAL;
+ if (res->a0 == PSCI_RET_DISABLED)
+ return -ENODATA;
if (res->a0 != PSCI_RET_SUCCESS)
return -EIO;
return 0;
@@ -131,10 +133,19 @@ static int smcwd_probe(struct platform_device *pdev)
wdd->info = &smcwd_info;
/* get_timeleft is optional */
- if (smcwd_call(wdd, SMCWD_GET_TIMELEFT, 0, NULL))
- wdd->ops = &smcwd_ops;
- else
+ err = smcwd_call(wdd, SMCWD_GET_TIMELEFT, 0, NULL);
+ switch (err) {
+ case 0:
+ set_bit(WDOG_HW_RUNNING, &wdd->status);
+ fallthrough;
+ case -ENODATA:
wdd->ops = &smcwd_timeleft_ops;
+ break;
+ default:
+ wdd->ops = &smcwd_ops;
+ break;
+ }
+
wdd->timeout = res.a2;
wdd->max_timeout = res.a2;
wdd->min_timeout = res.a1;
The optional SMCWD_GET_TIMELEFT command can be used to detect if the watchdog has already been started. See the implementation in OP-TEE secure OS [1]. At probe time, check if the watchdog is already started and then set WDOG_HW_RUNNING in the watchdog status. This will cause the watchdog framework to ping the watchdog until a userspace watchdog daemon takes over the control. Link: https://github.com/OP-TEE/optee_os/commit/a7f2d4bd8632 [1] Signed-off-by: Antonio Borneo <antonio.borneo@foss.st.com> --- drivers/watchdog/arm_smc_wdt.c | 17 ++++++++++++++--- 1 file changed, 14 insertions(+), 3 deletions(-) base-commit: a5806cd506af5a7c19bcd596e4708b5c464bfd21