drivers: stm32_iwdg: add get_timeleft watchdog handler

Implement .get_timeleft() watchdog operation handler for non-secure world to query the watchdog device state. System time is logged a each watchdog refresh to estimate time remaining before the watchdog elapses. This change declare arm_cntpct_time_source and unpaged for stm32mp15 platform compliance. Change-Id: I15e283fa0fa8904b8a22da15283a9ca94639599e Signed-off-by: Antonio Borneo <[email protected]> Signed-off-by: Etienne Carriere <[email protected]>
etienne-lms · Dec 20, 2023 · db73e79 · db73e79
1 parent 661a146
commit db73e79
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diff --git a/core/arch/arm/kernel/tee_time_arm_cntpct.c b/core/arch/arm/kernel/tee_time_arm_cntpct.c
@@ -5,6 +5,7 @@
 
 #include <arm.h>
 #include <crypto/crypto.h>
+#include <keep.h>
 #include <kernel/misc.h>
 #include <kernel/tee_time.h>
 #include <kernel/time_source.h>
@@ -32,6 +33,7 @@ static const struct time_source arm_cntpct_time_source = {
 };
 
 REGISTER_TIME_SOURCE(arm_cntpct_time_source)
+DECLARE_KEEP_PAGER(arm_cntpct_time_source);
 
 /*
  * We collect jitter using cntpct in 32- or 64-bit mode that is typically

diff --git a/core/drivers/stm32_iwdg.c b/core/drivers/stm32_iwdg.c
@@ -18,6 +18,7 @@
 #include <kernel/panic.h>
 #include <kernel/pm.h>
 #include <kernel/spinlock.h>
+#include <kernel/tee_time.h>
 #include <libfdt.h>
 #include <mm/core_memprot.h>
 #include <sm/sm.h>
@@ -89,6 +90,7 @@
  * @flags - Property flags for the IWDG instance
  * @timeout - Watchdog elaspure timeout
  * @hw_version - Watchdog HW version
+ * @last_refresh - Time of last watchdog refresh
  * @wdt_chip - Wathcdog chip instance
  * @link - Link in registered watchdog instance list
  */
@@ -102,6 +104,7 @@ struct stm32_iwdg_device {
 	uint32_t flags;
 	unsigned long timeout;
 	unsigned int hw_version;
+	TEE_Time last_refresh;
 	struct wdt_chip wdt_chip;
 	SLIST_ENTRY(stm32_iwdg_device) link;
 };
@@ -234,13 +237,19 @@ static TEE_Result configure_timeout(struct stm32_iwdg_device *iwdg)
 
 static void iwdg_start(struct stm32_iwdg_device *iwdg)
 {
+	if (tee_time_get_sys_time(&iwdg->last_refresh))
+		panic();
+
 	io_write32(get_base(iwdg) + IWDG_KR_OFFSET, IWDG_KR_START_KEY);
 
 	iwdg_wdt_set_enabled(iwdg);
 }
 
 static void iwdg_refresh(struct stm32_iwdg_device *iwdg)
 {
+	if (tee_time_get_sys_time(&iwdg->last_refresh))
+		panic();
+
 	io_write32(get_base(iwdg) + IWDG_KR_OFFSET, IWDG_KR_RELOAD_KEY);
 }
 
@@ -305,11 +314,43 @@ static TEE_Result iwdg_wdt_set_timeout(struct wdt_chip *chip,
 	return TEE_SUCCESS;
 }
 
+static TEE_Result iwdg_wdt_get_timeleft(struct wdt_chip *chip, bool *is_enabled,
+					unsigned long *timeleft)
+{
+	struct stm32_iwdg_device *iwdg = wdt_chip_to_iwdg(chip);
+	TEE_Result res = TEE_ERROR_GENERIC;
+	TEE_Time time = { };
+	TEE_Time now = { };
+
+	*is_enabled = iwdg_wdt_is_enabled(iwdg);
+
+	if (!*is_enabled) {
+		*timeleft = 0;
+		return TEE_SUCCESS;
+	}
+
+	res = tee_time_get_sys_time(&now);
+	if (res)
+		panic();
+
+	time.seconds = iwdg->timeout;
+	TEE_TIME_ADD(iwdg->last_refresh, time, time);
+	if (TEE_TIME_LE(time, now)) {
+		*timeleft = 0;
+	} else {
+		TEE_TIME_SUB(time, now, time);
+		*timeleft = time.seconds;
+	}
+
+	return TEE_SUCCESS;
+}
+
 static const struct wdt_ops stm32_iwdg_ops = {
 	.init = iwdg_wdt_init,
 	.start = iwdg_wdt_start,
 	.ping = iwdg_wdt_refresh,
 	.set_timeout = iwdg_wdt_set_timeout,
+	.get_timeleft = iwdg_wdt_get_timeleft,
 };
 DECLARE_KEEP_PAGER(stm32_iwdg_ops);