i.MX: Allow GPT timer to rollover.
GPT timer need to rollover when it reaches 0xffffffff.
It also need to reset to 0 when in "restart mode" and crossing the
compare 1 register.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Jean-Christophe Dubois <jcd@tribudubois.net>
Message-id: 6e2b36117a249a78bf822dd59a390368f407136e.1456868959.git.jcd@tribudubois.net
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
diff --git a/hw/timer/imx_gpt.c b/hw/timer/imx_gpt.c
index 5cdc3b3..916577b 100644
--- a/hw/timer/imx_gpt.c
+++ b/hw/timer/imx_gpt.c
@@ -134,7 +134,7 @@
static void imx_gpt_compute_next_timeout(IMXGPTState *s, bool event)
{
uint32_t timeout = GPT_TIMER_MAX;
- uint32_t count = 0;
+ uint32_t count;
long long limit;
if (!(s->cr & GPT_CR_EN)) {
@@ -142,20 +142,23 @@
return;
}
+ /* update the count */
+ count = imx_gpt_update_count(s);
+
if (event) {
- /* This is a timer event */
-
- if ((s->cr & GPT_CR_FRR) && (s->next_timeout != GPT_TIMER_MAX)) {
- /*
- * if we are in free running mode and we have not reached
- * the GPT_TIMER_MAX limit, then update the count
+ /*
+ * This is an event (the ptimer reached 0 and stopped), and the
+ * timer counter is now equal to s->next_timeout.
+ */
+ if (!(s->cr & GPT_CR_FRR) && (count == s->ocr1)) {
+ /* We are in restart mode and we crossed the compare channel 1
+ * value. We need to reset the counter to 0.
*/
- count = imx_gpt_update_count(s);
+ count = s->cnt = s->next_timeout = 0;
+ } else if (count == GPT_TIMER_MAX) {
+ /* We reached GPT_TIMER_MAX so we need to rollover */
+ count = s->cnt = s->next_timeout = 0;
}
- } else {
- /* not a timer event, then just update the count */
-
- count = imx_gpt_update_count(s);
}
/* now, find the next timeout related to count */
