@@ -253,6 +253,7 @@ static const char * const mlxbf_rsh_log_level[] = {
static DEFINE_MUTEX(icm_ops_lock);
static DEFINE_MUTEX(os_up_lock);
static DEFINE_MUTEX(mfg_ops_lock);
+static DEFINE_MUTEX(rtc_ops_lock);
/*
* Objects are stored within the MFG partition per type.
@@ -651,6 +652,23 @@ static ssize_t large_icm_store(struct device *dev,
return res.a0 ? -EPERM : count;
}
+static ssize_t rtc_battery_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct arm_smccc_res res;
+
+ mutex_lock(&rtc_ops_lock);
+ arm_smccc_smc(MLNX_HANDLE_GET_RTC_LOW_BATT, 0, 0, 0, 0,
+ 0, 0, 0, &res);
+ mutex_unlock(&rtc_ops_lock);
+
+ if (res.a0)
+ return -EPERM;
+
+ return snprintf(buf, PAGE_SIZE, "0x%lx", res.a1);
+}
+
static ssize_t os_up_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
@@ -1253,6 +1271,7 @@ static DEVICE_ATTR_RW(sn);
static DEVICE_ATTR_RW(uuid);
static DEVICE_ATTR_RW(rev);
static DEVICE_ATTR_WO(mfg_lock);
+static DEVICE_ATTR_RO(rtc_battery);
static struct attribute *mlxbf_bootctl_attrs[] = {
&dev_attr_post_reset_wdog.attr,
@@ -1272,6 +1291,7 @@ static struct attribute *mlxbf_bootctl_attrs[] = {
&dev_attr_uuid.attr,
&dev_attr_rev.attr,
&dev_attr_mfg_lock.attr,
+ &dev_attr_rtc_battery.attr,
NULL
};
@@ -103,6 +103,11 @@
*/
#define MLNX_HANDLE_OS_UP 0x82000014
+/*
+ * SMC function ID to get and clear the RTC low voltage bit
+ */
+#define MLNX_HANDLE_GET_RTC_LOW_BATT 0x82000023
+
/* SMC function IDs for SiP Service queries */
#define MLXBF_BOOTCTL_SIP_SVC_CALL_COUNT 0x8200ff00
#define MLXBF_BOOTCTL_SIP_SVC_UID 0x8200ff01