summaryrefslogtreecommitdiff
path: root/payloads/libpayload
diff options
context:
space:
mode:
authorGabe Black <gabeblack@google.com>2013-12-06 23:30:10 -0800
committerIsaac Christensen <isaac.christensen@se-eng.com>2014-09-15 19:01:03 +0200
commit125a6a22f81b3cf11732ce2a0e77652661fa0764 (patch)
tree6ecf832074b545afe304ae06ad9ff7b66a04f68f /payloads/libpayload
parent5f43184349e75415126937c60b0fbb9dc6bd2a35 (diff)
downloadcoreboot-125a6a22f81b3cf11732ce2a0e77652661fa0764.tar.xz
libpayload: Add a timer_us() function.
This function returns the number of microseconds scaled from the number of raw timer ticks. It accepts a base parameter which is subtracted from the current time, which makes it easy to keep track of relative times. Change-Id: I55f2f9e90c0e12cda430bbe88b044f12b0b563c8 Signed-off-by: Gabe Black <gabeblack@google.com> Reviewed-on: https://chromium-review.googlesource.com/179600 Reviewed-by: Ronald Minnich <rminnich@chromium.org> Commit-Queue: Gabe Black <gabeblack@chromium.org> Tested-by: Gabe Black <gabeblack@chromium.org> (cherry picked from commit 4dd549e18d170dbf918c5b4b11bbe1f4e99b6695) Signed-off-by: Isaac Christensen <isaac.christensen@se-eng.com> Reviewed-on: http://review.coreboot.org/6897 Tested-by: build bot (Jenkins) Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>
Diffstat (limited to 'payloads/libpayload')
-rw-r--r--payloads/libpayload/include/libpayload.h1
-rw-r--r--payloads/libpayload/libc/time.c17
2 files changed, 18 insertions, 0 deletions
diff --git a/payloads/libpayload/include/libpayload.h b/payloads/libpayload/include/libpayload.h
index 3e48650ec1..b36b40cb7d 100644
--- a/payloads/libpayload/include/libpayload.h
+++ b/payloads/libpayload/include/libpayload.h
@@ -423,6 +423,7 @@ int lib_get_sysinfo(void);
unsigned int get_cpu_speed(void);
uint64_t timer_hz(void);
uint64_t timer_raw_value(void);
+uint64_t timer_us(uint64_t base);
/* Generic. */
void ndelay(unsigned int n);
void udelay(unsigned int n);
diff --git a/payloads/libpayload/libc/time.c b/payloads/libpayload/libc/time.c
index ec1c85ce8c..0d8163495b 100644
--- a/payloads/libpayload/libc/time.c
+++ b/payloads/libpayload/libc/time.c
@@ -189,3 +189,20 @@ void delay(unsigned int s)
{
_delay((uint64_t)s * timer_hz());
}
+
+u64 timer_us(u64 base)
+{
+ static u64 hz;
+
+ // Only check timer_hz once. Assume it doesn't change.
+ if (hz == 0) {
+ hz = timer_hz();
+ if (hz < 1000000) {
+ printf("Timer frequency %lld is too low, "
+ "must be at least 1MHz.\n", hz);
+ halt();
+ }
+ }
+
+ return timer_raw_value() / (hz / 1000000) - base;
+}