diff options
| author | Adnan Rahman Chowdhury <[email protected]> | 2022-06-30 10:46:35 +0100 |
|---|---|---|
| committer | Anup Patel <[email protected]> | 2022-07-08 14:51:24 +0530 |
| commit | 994c8cfb29d0b53bbcc774a728cad778aeece6ac (patch) | |
| tree | 78169571385306969a1b507d6fa045879e3a30a2 /lib | |
| parent | 4489876e933d8ba0d8bc6c64bae71e295d45faac (diff) | |
lib: sbi_timer: Added a conditional wait function which can timeout
Motivation: Suppose a peripheral needs to be configured to transmit
data. There is an SFR bit which indicates that the peripheral is ready
to transmit. The firmware should check the bit and will only transmit
data when the peripheral is ready. When the firmware starts polling the
SFR, the peripheral could be busy transmitting/receiving other data so
the firmware must wait till that completes. Assuming that there is no
other way, the firmware shouldn't wait indefinitely.
The function sbi_timer_waitms_until() will constantly check whether a
certain condition is satisfied, or timeout occurs. It can be used for
the cases when a timeout is required.
Signed-off-by: Adnan Rahman Chowdhury <[email protected]>
Reviewed-by: Xiang W <[email protected]>
Reviewed-by: Anup Patel <[email protected]>
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/sbi/sbi_timer.c | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/lib/sbi/sbi_timer.c b/lib/sbi/sbi_timer.c index b0a6e63f..4b24cbeb 100644 --- a/lib/sbi/sbi_timer.c +++ b/lib/sbi/sbi_timer.c @@ -76,6 +76,19 @@ void sbi_timer_delay_loop(ulong units, u64 unit_freq, delay_fn(opaque); } +bool sbi_timer_waitms_until(bool (*predicate)(void *), void *arg, + uint64_t timeout_ms) +{ + uint64_t start_time = sbi_timer_value(); + uint64_t ticks = + (sbi_timer_get_device()->timer_freq / 1000) * + timeout_ms; + while(!predicate(arg)) + if (sbi_timer_value() - start_time >= ticks) + return false; + return true; +} + u64 sbi_timer_value(void) { if (get_time_val) |