Charger: Remove old alarm interface and update timerfd interface

Oreo doesn't allow usage of the old alarm interface anymore, so
simply remove it and switch to timerfd. Also update the timerfd
interface from CAF O release

Change-Id: I22fc00630072cbf18976239dc039bf2135946045

charger/healthd_board_lineage.cpp

@@ -33,9 +33,10 @@
 #include <cutils/properties.h>
 
 #include <pthread.h>
-#include <linux/android_alarm.h>
-#include <sys/timerfd.h>
 #include <linux/rtc.h>
+#include <linux/time.h>
+#include <sys/epoll.h>
+#include <sys/timerfd.h>
 
 #include "healthd/healthd.h"
 #include "minui/minui.h"
@@ -106,12 +107,6 @@ enum alarm_time_type {
     RTC_TIME,
 };
 
-/*
- * shouldn't be changed after
- * reading from alarm register
- */
-static time_t alm_secs;
-
 static int alarm_get_time(enum alarm_time_type time_type,
                           time_t *secs)
 {
@@ -160,104 +155,88 @@ err:
     return -1;
 }
 
-#define ERR_SECS 2
-static int alarm_is_alm_expired()
+static void alarm_reboot(void)
 {
-    int rc;
-    time_t rtc_secs;
-
-    rc = alarm_get_time(RTC_TIME, &rtc_secs);
-    if (rc < 0)
-        return 0;
-
-    return (alm_secs >= rtc_secs - ERR_SECS &&
-            alm_secs <= rtc_secs + ERR_SECS) ? 1 : 0;
-}
-
-static int timerfd_set_reboot_time_and_wait(time_t secs)
-{
-    int fd;
-    int ret = -1;
-    fd = timerfd_create(CLOCK_REALTIME_ALARM, 0);
-    if (fd < 0) {
-        LOGE("Can't open timerfd alarm node\n");
-        goto err_return;
-    }
-
-    struct itimerspec spec;
-    memset(&spec, 0, sizeof(spec));
-    spec.it_value.tv_sec = secs;
-
-    if (timerfd_settime(fd, 0 /* relative */, &spec, NULL)) {
-        LOGE("Can't set timerfd alarm\n");
-        goto err_close;
-    }
-
-    uint64_t unused;
-    if (read(fd, &unused, sizeof(unused)) < 0) {
-       LOGE("Wait alarm error\n");
-       goto err_close;
-    }
-
-    ret = 0;
-err_close:
-    close(fd);
-err_return:
-    return ret;
+    LOGI("alarm time is up, reboot the phone!\n");
+    syscall(__NR_reboot, LINUX_REBOOT_MAGIC1, LINUX_REBOOT_MAGIC2,
+            LINUX_REBOOT_CMD_RESTART2, "rtc");
 }
 
 static int alarm_set_reboot_time_and_wait(time_t secs)
 {
-    int rc, fd;
+    int rc, epollfd, nevents;
+    int fd = 0;
     struct timespec ts;
+    epoll_event event, events[1];
+    struct itimerspec itval;
+
+    epollfd = epoll_create(1);
+    if (epollfd < 0) {
+        LOGE("epoll_create failed\n");
+        goto err;
+    }
 
-    fd = open("/dev/alarm", O_RDWR);
+    fd = timerfd_create(CLOCK_REALTIME_ALARM, 0);
     if (fd < 0) {
-        LOGE("Can't open alarm devfs node, trying timerfd\n");
-        return timerfd_set_reboot_time_and_wait(secs);
+        LOGE("timerfd_create failed\n");
+        goto err;
     }
 
-    /* get the elapsed realtime from boot time to now */
-    rc = ioctl(fd, ANDROID_ALARM_GET_TIME(
-                      ANDROID_ALARM_ELAPSED_REALTIME_WAKEUP), &ts);
+    event.events = EPOLLIN | EPOLLWAKEUP;
+    event.data.ptr = (void *)alarm_reboot;
+    rc = epoll_ctl(epollfd, EPOLL_CTL_ADD, fd, &event);
     if (rc < 0) {
-        LOGE("Unable to get elapsed realtime\n");
+        LOGE("epoll_ctl(EPOLL_CTL_ADD) failed \n");
         goto err;
     }
 
-    /* calculate the elapsed time from boot time to reboot time */
-    ts.tv_sec += secs;
-    ts.tv_nsec = 0;
+    itval.it_value.tv_sec = secs;
+    itval.it_value.tv_nsec = 0;
+
+    itval.it_interval.tv_sec = 0;
+    itval.it_interval.tv_nsec = 0;
 
-    rc = ioctl(fd, ANDROID_ALARM_SET(
-                      ANDROID_ALARM_ELAPSED_REALTIME_WAKEUP), &ts);
+    rc = timerfd_settime(fd, TFD_TIMER_ABSTIME, &itval, NULL);
     if (rc < 0) {
-        LOGE("Unable to set reboot time to %ld\n", secs);
+        LOGE("timerfd_settime failed %d\n",rc);
         goto err;
     }
 
-    do {
-        rc = ioctl(fd, ANDROID_ALARM_WAIT);
-    } while ((rc < 0 && errno == EINTR) || !alarm_is_alm_expired());
+    nevents = epoll_wait(epollfd, events, 1, -1);
 
-    if (rc <= 0) {
+    if (nevents <= 0) {
         LOGE("Unable to wait on alarm\n");
         goto err;
+    } else {
+        (*(void (*)())events[0].data.ptr)();
     }
 
+    close(epollfd);
     close(fd);
     return 0;
 
 err:
+    if (epollfd > 0)
+        close(epollfd);
+
     if (fd >= 0)
         close(fd);
     return -1;
 }
 
+/*
+ * 10s the estimated time from timestamp of alarm thread start
+ * to timestamp of android boot completed.
+ */
+#define TIME_DELTA 10
+
+/* seconds of 1 minute*/
+#define ONE_MINUTE 60
 static void *alarm_thread(void *)
 {
-    time_t rtc_secs, rb_secs;
+    time_t rtc_secs, alarm_secs;
     int rc;
+    timespec ts;
 
     /*
      * to support power off alarm, the time
@@ -266,31 +245,39 @@ static void *alarm_thread(void *)
      * earlier than the actual alarm time
      * set by user
      */
-    rc = alarm_get_time(ALARM_TIME, &alm_secs);
-    LOGI("RTC Alarm %ld\n", alm_secs);
-    if (rc < 0 || !alm_secs)
+    rc = alarm_get_time(ALARM_TIME, &alarm_secs);
+    if (rc < 0 || !alarm_secs)
         goto err;
 
     rc = alarm_get_time(RTC_TIME, &rtc_secs);
-    LOGI("RTC Clock %ld\n", rtc_secs);
-    if (rc < 0)
+    if (rc < 0 || !rtc_secs)
         goto err;
+    LOGI("alarm time in rtc is %ld, rtc time is %ld\n", alarm_secs, rtc_secs);
+
+    if (alarm_secs <= rtc_secs) {
+        clock_gettime(CLOCK_BOOTTIME, &ts);
+
+        /*
+         * It is possible that last power off alarm time is up at this point.
+         * (alarm_secs + ONE_MINUTE) is the final alarm time to fire.
+         * (rtc_secs + ts.tv_sec + TIME_DELTA) is the estimated time of next
+         * boot completed to fire alarm.
+         * If the final alarm time is less than the estimated time of next boot
+         * completed to fire, that means it is not able to fire the last power
+         * off alarm at the right time, so just miss it.
+         */
+        if (alarm_secs + ONE_MINUTE < rtc_secs + ts.tv_sec + TIME_DELTA) {
+            LOGE("alarm is missed\n");
+            goto err;
+        }
 
-    /*
-     * calculate the reboot time after which
-     * the phone will reboot
-     */
-    rb_secs = alm_secs - rtc_secs;
-    if (rb_secs <= 0)
-        goto err;
+        alarm_reboot();
+    }
 
-    rc = alarm_set_reboot_time_and_wait(rb_secs);
+    rc = alarm_set_reboot_time_and_wait(alarm_secs);
     if (rc < 0)
         goto err;
 
-    LOGI("Exit from power off charging, reboot the phone!\n");
-    android_reboot(ANDROID_RB_RESTART, 0, 0);
-
 err:
     LOGE("Exit from alarm thread\n");
     return NULL;