linux: Rework timer_check_periodic() to use ticks

Avoid using a 'struct timespec' to simplify the code.

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>

src/linux/internal.h

@@ -2,7 +2,7 @@
 #define __LINUX_INTERNAL_H
 // Local definitions for micro-controllers running on linux
 
-#include <time.h> // struct timespec
+#include <stdint.h> // uint32_t
 #include "autoconf.h" // CONFIG_CLOCK_FREQ
 
 #define MAX_GPIO_LINES    256
@@ -22,7 +22,7 @@ int console_setup(char *name);
 void console_sleep(struct timespec ts);
 
 // timer.c
-int timer_check_periodic(struct timespec *ts);
+int timer_check_periodic(uint32_t *ts);
 
 // watchdog.c
 int watchdog_setup(void);

src/linux/timer.c

@@ -75,17 +75,6 @@ timespec_read(void)
     return ts;
 }
 
-// Check if a given time has past
-int
-timer_check_periodic(struct timespec *ts)
-{
-    if (timespec_is_before(TimerInfo.next_wake, *ts))
-        return 0;
-    *ts = TimerInfo.next_wake;
-    ts->tv_sec += 2;
-    return 1;
-}
-
 
 /****************************************************************
  * Timers
@@ -93,6 +82,17 @@ timer_check_periodic(struct timespec *ts)
 
 DECL_CONSTANT("CLOCK_FREQ", CONFIG_CLOCK_FREQ);
 
+// Check if a given time has past
+int
+timer_check_periodic(uint32_t *ts)
+{
+    uint32_t lrt = TimerInfo.last_read_time;
+    if (timer_is_before(lrt, *ts))
+        return 0;
+    *ts = lrt + timer_from_us(2000000);
+    return 1;
+}
+
 // Return the number of clock ticks for a given number of microseconds
 uint32_t
 timer_from_us(uint32_t us)

src/linux/watchdog.c

@@ -26,7 +26,7 @@ watchdog_setup(void)
 void
 watchdog_task(void)
 {
-    static struct timespec next_watchdog_time;
+    static uint32_t next_watchdog_time;
     if (watchdog_fd < 0 || !timer_check_periodic(&next_watchdog_time))
         return;
     int ret = write(watchdog_fd, ".", 1);