diff options
| author | Jean-Christophe Dubois <jcd@tribudubois.net> | 2016-03-16 17:05:59 +0000 |
|---|---|---|
| committer | Peter Maydell <peter.maydell@linaro.org> | 2016-03-16 17:42:18 +0000 |
| commit | 4833e15f7487440243377250d7d76b96ba4c210c (patch) | |
| tree | 70d2c624594ec0a418dc514a0da65d44166e4b2a | |
| parent | 9c94d8e6c9a31a74f18168ca8d74c3e3f7c0e40e (diff) | |
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>
| -rw-r--r-- | hw/timer/imx_gpt.c | 27 |
1 files changed, 15 insertions, 12 deletions
diff --git a/hw/timer/imx_gpt.c b/hw/timer/imx_gpt.c index 5cdc3b3c8d..916577b463 100644 --- a/hw/timer/imx_gpt.c +++ b/hw/timer/imx_gpt.c @@ -134,7 +134,7 @@ static inline uint32_t imx_gpt_find_limit(uint32_t count, uint32_t reg, 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 @@ static void imx_gpt_compute_next_timeout(IMXGPTState *s, bool event) return; } - if (event) { - /* This is a timer event */ + /* update the count */ + count = imx_gpt_update_count(s); - 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 + if (event) { + /* + * 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 */ |