test: periph_timer: check if argument is passed.

tests/periph_timer/main.c

@@ -34,15 +34,17 @@
 #define MAX_CHANNELS        (10U)
 #define TIM_SPEED           (1000000ul) /* try to run with 1MHz */
 #define CHAN_OFFSET         (5000U)     /* fire every 5ms */
+#define COOKIE              (100U)      /* for checking if arg is passed */
 
 static volatile int fired;
 static volatile uint32_t sw_count;
 static volatile uint32_t timeouts[MAX_CHANNELS];
+static volatile unsigned args[MAX_CHANNELS];
 
 static void cb(void *arg, int chan)
 {
-    (void)arg;
     timeouts[chan] = sw_count;
+    args[chan] = (unsigned)arg + chan;
     fired++;
 }
 
@@ -55,10 +57,11 @@ static int test_timer(unsigned num)
     fired = 0;
     for (unsigned i = 0; i < MAX_CHANNELS; i++) {
         timeouts[i] = 0;
+        args[i] = UINT_MAX;
     }
 
     /* initialize and halt timer */
-    if (timer_init(TIMER_DEV(num), TIM_SPEED, cb, NULL) < 0) {
+    if (timer_init(TIMER_DEV(num), TIM_SPEED, cb, (void *)(COOKIE * num)) < 0) {
         printf("TIMER_%u: ERROR on initialization - skipping\n\n", num);
         return 0;
     }
@@ -91,6 +94,10 @@ static int test_timer(unsigned num)
     } while (fired != set);
     /* collect results */
     for (int i = 0; i < fired; i++) {
+        if (args[i] != ((COOKIE * num) + i)) {
+            printf("TIMER_%u: ERROR callback argument mismatch\n\n", num);
+            return 0;
+        }
         printf("TIMER_%u: channel %i fired at SW count %8u",
                num, i, (unsigned)timeouts[i]);
         if (i == 0) {