diff --git a/arch/arm/src/sama5/sam_freerun.c b/arch/arm/src/sama5/sam_freerun.c
index b4813c57c0a..f49bed2f534 100644
--- a/arch/arm/src/sama5/sam_freerun.c
+++ b/arch/arm/src/sama5/sam_freerun.c
@@ -88,17 +88,17 @@
  *   this interrupt will occur.  We will just increment an overflow count.
  *
  * Input Parameters:
- *   handle - The handle that represents the timer state
- *   arg    - An opaque argument provided when the interrupt was registered
- *   sr     - The value of the timer interrupt status register at the time
- *            that the interrupt occurred.
+ *   tch - The handle that represents the timer state
+ *   arg - An opaque argument provided when the interrupt was registered
+ *   sr  - The value of the timer interrupt status register at the time
+ *         that the interrupt occurred.
  *
  * Returned Value:
  *   None
  *
  ****************************************************************************/
 
-static void sam_freerun_handler(TC_HANDLE handle, void *arg, uint32_t sr)
+static void sam_freerun_handler(TC_HANDLE tch, void *arg, uint32_t sr)
 {
   struct sam_freerun_s *freerun = (struct sam_freerun_s *)arg;
   DEBUGASSERT(freerun && freerun->overflow < UINT16_MAX);
@@ -185,8 +185,8 @@ int sam_freerun_initialize(struct sam_freerun_s *freerun, int chan,
           TC_CMR_BCPB_NONE   | TC_CMR_BCPC_NONE    | TC_CMR_BEEVT_NONE  |
           TC_CMR_BSWTRG_NONE);
 
-  freerun->handle = sam_tc_allocate(chan, cmr);
-  if (!freerun->handle)
+  freerun->tch = sam_tc_allocate(chan, cmr);
+  if (!freerun->tch)
     {
       tcdbg("ERROR: Failed to allocate timer channel %d\n", chan);
       return -EBUSY;
@@ -202,12 +202,12 @@ int sam_freerun_initialize(struct sam_freerun_s *freerun, int chan,
 
   /* Set up to receive the callback when the counter overflow occurs */
 
-  (void)sam_tc_attach(freerun->handle, sam_freerun_handler, freerun,
+  (void)sam_tc_attach(freerun->tch, sam_freerun_handler, freerun,
                       TC_INT_COVFS);
 
   /* Start the counter */
 
-  sam_tc_start(freerun->handle);
+  sam_tc_start(freerun->tch);
 
   return OK;
 }
@@ -241,13 +241,15 @@ int sam_freerun_counter(struct sam_freerun_s *freerun, struct timespec *ts)
   uint32_t sec;
   irqstate_t flags;
 
+  DEBUGASSERT(freerun && freerun->tch && ts);
+
   /* Temporarily disable the overflow counter */
 
   flags    = irqsave();
   overflow = freerun->overflow;
-  counter  = sam_tc_getcounter(freerun->handle);
-  sr       = sam_tc_getpending(freerun->handle);
-  verify   = sam_tc_getcounter(freerun->handle);
+  counter  = sam_tc_getcounter(freerun->tch);
+  sr       = sam_tc_getpending(freerun->tch);
+  verify   = sam_tc_getcounter(freerun->tch);
   irqrestore(flags);
 
   tcvdbg("counter=%lu (%lu) overflow=%lu, sr=%08lx\n",
@@ -307,14 +309,17 @@ int sam_freerun_counter(struct sam_freerun_s *freerun, struct timespec *ts)
 
 int sam_freerun_uninitialize(struct sam_freerun_s *freerun)
 {
+  DEBUGASSERT(freerun && freerun->tch);
+
   /* Now we can disable the timer interrupt and disable the timer. */
 
-  sam_tc_attach(freerun->handle, NULL, NULL, 0);
-  sam_tc_stop(freerun->handle);
+  sam_tc_attach(freerun->tch, NULL, NULL, 0);
+  sam_tc_stop(freerun->tch);
 
   /* Free the timer */
 
-  sam_tc_free(freerun->handle);
+  sam_tc_free(freerun->tch);
+  freerun->tch = NULL;
   return OK;
 }
 
diff --git a/arch/arm/src/sama5/sam_freerun.h b/arch/arm/src/sama5/sam_freerun.h
index 48ce56e9aec..a68865378d4 100644
--- a/arch/arm/src/sama5/sam_freerun.h
+++ b/arch/arm/src/sama5/sam_freerun.h
@@ -69,7 +69,7 @@ struct sam_freerun_s
   bool running;              /* True: the timer is running */
   uint16_t resolution;       /* Timer resolution in microseconds */
   uint16_t overflow;         /* Timer counter overflow */
-  TC_HANDLE handle;          /* Handle returned by sam_tc_initialize() */
+  TC_HANDLE tch;             /* Handle returned by sam_tc_initialize() */
 };
 
 /****************************************************************************
diff --git a/arch/arm/src/sama5/sam_oneshot.c b/arch/arm/src/sama5/sam_oneshot.c
index d8bb22c0aed..4366194a474 100644
--- a/arch/arm/src/sama5/sam_oneshot.c
+++ b/arch/arm/src/sama5/sam_oneshot.c
@@ -80,6 +80,7 @@
 /****************************************************************************
  * Private Functions
  ****************************************************************************/
+
 /****************************************************************************
  * Name: sam_oneshot_handler
  *
@@ -121,9 +122,9 @@ static void sam_oneshot_handler(TC_HANDLE tch, void *arg, uint32_t sr)
 
   /* Forward the event, clearing out any vestiges */
 
-  oneshot_handler  = oneshot->handler;
+  oneshot_handler  = (struct sam_oneshot_s *)oneshot->handler;
   oneshot->handler = NULL;
-  oneshot_arg      = oneshot->arg;
+  oneshot_arg      = (void *)oneshot->arg;
   oneshot->arg     = NULL;
 
   oneshot_handler(oneshot_arg);
@@ -368,7 +369,7 @@ int sam_oneshot_cancel(struct sam_oneshot_s *oneshot, struct timespec *ts)
    * following logic depends on this fact.
    */
 
-  tcvdbg("Canceling...\n");
+  tcvdbg("Cancelling...\n");
 
   count = sam_tc_getcounter(oneshot->tch);
   rc    = sam_tc_getregister(oneshot->tch, TC_REGC);