bcl: Add mitigation ready check

Instead of relying on vendor.thermal.link_ready property to gate write
to BCL's SYSFS node, adding mitigation ready SYSFS so that writes to
BCL's SYSFS node would not cause NULL pointer dereference.

Bug: 249130916
Test: Confirm property vendor.brownout.mitigation.ready is set
Signed-off-by: George Lee <geolee@google.com>
Change-Id: Ic643a07ddb657cfc7e22537d5d25d0d99324e31c

1 files changed, 19 insertions, 0 deletions

diff --git a/battery_mitigation/battery_mitigation.cpp b/battery_mitigation/battery_mitigation.cpp
index 5784b27..2204bd5 100644
--- a/battery_mitigation/battery_mitigation.cpp
+++ b/battery_mitigation/battery_mitigation.cpp
@@ -63,8 +63,27 @@ const struct MitigationConfig::Config cfg = {
     .LogFilePath = "/data/vendor/mitigation/thismeal.txt",
 };
 
+const char kReadyFilePath[] = "/sys/devices/virtual/pmic/mitigation/instruction/ready";
+const char kReadyProperty[] = "vendor.brownout.mitigation.ready";
+
 int main(int /*argc*/, char ** /*argv*/) {
     bmSp = new BatteryMitigation(cfg);
+    bool isBatteryMitigationReady = false;
+    std::string ready_str;
+    int val = 0;
+    while (!isBatteryMitigationReady) {
+        if (!android::base::ReadFileToString(kReadyFilePath, &ready_str)) {
+            continue;
+        }
+        ready_str = android::base::Trim(ready_str);
+        if (!android::base::ParseInt(ready_str, &val)) {
+            continue;
+        }
+        if (val == 1) {
+            isBatteryMitigationReady = true;
+        }
+    }
+    android::base::SetProperty(kReadyProperty, "1");
     while (true) {
         pause();
     }