diff options
-rw-r--r-- | Makefile | 22 | ||||
-rw-r--r-- | udelay.c | 56 |
2 files changed, 78 insertions, 0 deletions
@@ -1003,6 +1003,9 @@ FEATURE_CFLAGS += $(call debug_shell,grep -q "UTSNAME := yes" .features && print # We could use PULLED_IN_LIBS, but that would be ugly. FEATURE_LIBS += $(call debug_shell,grep -q "NEEDLIBZ := yes" .libdeps && printf "%s" "-lz") +FEATURE_CFLAGS += $(call debug_shell,grep -q "CLOCK_GETTIME := yes" .features && printf "%s" "-D'HAVE_CLOCK_GETTIME=1'") +FEATURE_LIBS += $(call debug_shell,grep -q "CLOCK_GETTIME := yes" .features && printf "%s" "-lrt") + LIBFLASHROM_OBJS = $(CHIP_OBJS) $(PROGRAMMER_OBJS) $(LIB_OBJS) OBJS = $(CLI_OBJS) $(LIBFLASHROM_OBJS) @@ -1299,6 +1302,18 @@ int main(int argc, char **argv) endef export LINUX_I2C_TEST +define CLOCK_GETTIME_TEST +#include <time.h> + +int main(int argc, char **argv) +{ + struct timespec res; + clock_gettime(CLOCK_REALTIME, &res); + return 0; +} +endef +export CLOCK_GETTIME_TEST + features: compiler @echo "FEATURES := yes" > .features.tmp ifneq ($(NEED_LIBFTDI), ) @@ -1341,6 +1356,13 @@ endif @ { $(CC) $(CPPFLAGS) $(CFLAGS) $(LDFLAGS) .featuretest.c -o .featuretest$(EXEC_SUFFIX) >&2 && \ ( echo "found."; echo "UTSNAME := yes" >> .features.tmp ) || \ ( echo "not found."; echo "UTSNAME := no" >> .features.tmp ) } 2>>$(BUILD_DETAILS_FILE) | tee -a $(BUILD_DETAILS_FILE) + @printf "Checking for clock_gettime support... " | tee -a $(BUILD_DETAILS_FILE) + @echo "$$CLOCK_GETTIME_TEST" >.featuretest.c + @printf "\nexec: %s\n" "$(CC) $(CPPFLAGS) $(CFLAGS) $(LDFLAGS) -lrt .featuretest.c -o .featuretest$(EXEC_SUFFIX)" >>$(BUILD_DETAILS_FILE) + @ { $(CC) $(CPPFLAGS) $(CFLAGS) $(LDFLAGS) -lrt .featuretest.c -o .featuretest$(EXEC_SUFFIX) >&2 && \ + ( echo "found."; echo "CLOCK_GETTIME := yes" >>.features.tmp ) || \ + ( echo "not found."; echo "CLOCK_GETTIME := no" >>.features.tmp ) } \ + 2>>$(BUILD_DETAILS_FILE) | tee -a $(BUILD_DETAILS_FILE) @$(DIFF) -q .features.tmp .features >/dev/null 2>&1 && rm .features.tmp || mv .features.tmp .features @rm -f .featuretest.c .featuretest$(EXEC_SUFFIX) @@ -21,13 +21,64 @@ #ifndef __LIBPAYLOAD__ +#include <stdbool.h> #include <unistd.h> +#include <errno.h> #include <time.h> #include <sys/time.h> #include <stdlib.h> #include <limits.h> #include "flash.h" +static bool use_clock_gettime = false; + +#if HAVE_CLOCK_GETTIME == 1 + +#ifdef _POSIX_MONOTONIC_CLOCK +static clockid_t clock_id = CLOCK_MONOTONIC; +#else +static clockid_t clock_id = CLOCK_REALTIME; +#endif + +static void clock_usec_delay(int usecs) +{ + struct timespec now; + clock_gettime(clock_id, &now); + + const long end_nsec = now.tv_nsec + usecs * 1000L; + const struct timespec end = { + end_nsec / (1000 * 1000 * 1000) + now.tv_sec, + end_nsec % (1000 * 1000 * 1000) + }; + do { + clock_gettime(clock_id, &now); + } while (now.tv_sec < end.tv_sec || (now.tv_sec == end.tv_sec && now.tv_nsec < end.tv_nsec)); +} + +static int clock_check_res(void) +{ + struct timespec res; + if (!clock_getres(clock_id, &res)) { + if (res.tv_sec == 0 && res.tv_nsec <= 100) { + msg_pinfo("Using clock_gettime for delay loops (clk_id: %d, resolution: %ldns).\n", + (int)clock_id, res.tv_nsec); + use_clock_gettime = true; + return 1; + } + } else if (clock_id != CLOCK_REALTIME && errno == EINVAL) { + /* Try again with CLOCK_REALTIME. */ + clock_id = CLOCK_REALTIME; + return clock_check_res(); + } + return 0; +} +#else + +static inline void clock_usec_delay(int usecs) {} +static inline int clock_check_res(void) { return 0; } + +#endif /* HAVE_CLOCK_GETTIME == 1 */ + /* loops per microsecond */ static unsigned long micro = 1; @@ -87,6 +138,9 @@ static unsigned long measure_delay(unsigned int usecs) void myusec_calibrate_delay(void) { + if (clock_check_res()) + return; + unsigned long count = 1000; unsigned long timeusec, resolution; int i, tries = 0; @@ -189,6 +243,8 @@ void internal_delay(unsigned int usecs) /* If the delay is >1 s, use internal_sleep because timing does not need to be so precise. */ if (usecs > 1000000) { internal_sleep(usecs); + } else if (use_clock_gettime) { + clock_usec_delay(usecs); } else { myusec_delay(usecs); } |