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Deleted user 2017-09-01 09:29:40 +00:00 committed by GitHub
commit 65151365c3
2 changed files with 65 additions and 62 deletions

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@ -61,10 +61,9 @@ int sntp_set_servers(char *server_url[], int num_servers);
void sntp_set_update_delay(uint32_t ms); void sntp_set_update_delay(uint32_t ms);
/* /*
* Returns the time read from RTC counter, in seconds from Epoch. If * Returns the time read from RTC counter, in micro seconds from Epoch.
* us is not null, it will be filled with the microseconds.
*/ */
time_t sntp_get_rtc_time(int32_t *us); uint64_t sntp_get_rtc_time();
/* /*
* Update RTC timer. This function is called by the SNTP module each time * Update RTC timer. This function is called by the SNTP module each time

View file

@ -11,6 +11,8 @@
#include <espressif/esp_common.h> #include <espressif/esp_common.h>
#include <esp/timer.h> #include <esp/timer.h>
#include <esp/rtc_regs.h> #include <esp/rtc_regs.h>
#include "FreeRTOS.h"
#include "semphr.h"
#include "sntp.h" #include "sntp.h"
#define TIMER_COUNT RTC.COUNTER #define TIMER_COUNT RTC.COUNTER
@ -18,11 +20,14 @@
// daylight settings // daylight settings
// Base calculated with value obtained from NTP server (64 bits) // Base calculated with value obtained from NTP server (64 bits)
#define sntp_base (*((uint64_t*)RTC.SCRATCH)) #define sntp_base (*((uint64_t*)RTC.SCRATCH))
// Timer value when base was obtained // Timer value when sntp_base was obtained
#define tim_ref (RTC.SCRATCH[2]) #define tim_ref (RTC.SCRATCH[2])
// Calibration value // Calibration value
#define cal (RTC.SCRATCH[3]) #define cal (RTC.SCRATCH[3])
// To protect access to the above.
static xSemaphoreHandle sntp_sem = NULL;
// Timezone related data. // Timezone related data.
static struct timezone stz; static struct timezone stz;
@ -32,81 +37,80 @@ void sntp_init(void);
// Sets time zone. // Sets time zone.
// NOTE: Settings do not take effect until SNTP time is updated. // NOTE: Settings do not take effect until SNTP time is updated.
void sntp_set_timezone(const struct timezone *tz) { void sntp_set_timezone(const struct timezone *tz) {
if (tz) { if (tz) {
stz = *tz; stz = *tz;
} else { } else {
stz.tz_minuteswest = 0; stz.tz_minuteswest = 0;
stz.tz_dsttime = 0; stz.tz_dsttime = 0;
} }
} }
// Initialization // Initialization
void sntp_initialize(const struct timezone *tz) { void sntp_initialize(const struct timezone *tz) {
if (tz) { if (tz) {
stz = *tz; stz = *tz;
} else { } else {
stz.tz_minuteswest = 0; stz.tz_minuteswest = 0;
stz.tz_dsttime = 0; stz.tz_dsttime = 0;
} }
sntp_base = 0; sntp_base = 0;
// To avoid div by 0 exceptions if requesting time before SNTP config // To avoid div by 0 exceptions if requesting time before SNTP config
cal = 1; cal = 1;
tim_ref = TIMER_COUNT; tim_ref = TIMER_COUNT;
sntp_init(); sntp_sem = xSemaphoreCreateMutex();
if (sntp_sem == NULL)
printf("sntp: mutex creation failed\n");
sntp_init();
} }
// Check if a timer wrap has occurred. Compensate sntp_base reference // Return usecs.
// if affirmative. inline uint64_t sntp_get_rtc_time() {
// TODO: think about multitasking and race conditions xSemaphoreTake(sntp_sem, portMAX_DELAY);
static inline void sntp_check_timer_wrap(uint32_t current_value) { uint32_t tim = TIMER_COUNT;
if (current_value < tim_ref) { // Assume the difference does not overflow in which case
// Timer wrap has occurred, compensate by subtracting 2^32 to ref. // wrapping of the RTC timer still yields a good difference.
sntp_base -= 1LLU<<32; uint32_t diff = tim - tim_ref;
// DEBUG tim_ref = tim;
printf("\nTIMER WRAPPED!\n"); uint64_t diff_us = ((uint64_t)diff * cal) >> 12;
} uint64_t base = sntp_base + diff_us;
} sntp_base = base;
xSemaphoreGive(sntp_sem);
// Return secs. If us is not a null pointer, fill it with usecs return base;
inline time_t sntp_get_rtc_time(int32_t *us) {
time_t secs;
uint32_t tim;
uint64_t base;
tim = TIMER_COUNT;
// Check for timer wrap
sntp_check_timer_wrap(tim);
base = sntp_base + tim - tim_ref;
secs = base * cal / (1000000U<<12);
if (us) {
*us = base * cal % (1000000U<<12);
}
return secs;
} }
// Syscall implementation. doesn't seem to use tzp. // Syscall implementation. doesn't seem to use tzp.
int _gettimeofday_r(struct _reent *r, struct timeval *tp, void *tzp) { int _gettimeofday_r(struct _reent *r, struct timeval *tp, void *tzp) {
(void)r; (void)r;
// Syscall defined by xtensa newlib defines tzp as void* // Syscall defined by xtensa newlib defines tzp as void*
// So it looks like it is not used. Also check tp is not NULL // So it looks like it is not used. Also check tp is not NULL
if (tzp || !tp) return EINVAL; if (tzp || !tp) return EINVAL;
tp->tv_sec = sntp_get_rtc_time((int32_t*)&tp->tv_usec); uint64_t base = sntp_get_rtc_time();
return 0;
tp->tv_sec = base / 1000000U;
tp->tv_usec = base % 1000000U;
return 0;
} }
// Update RTC timer. Called by SNTP module each time it receives an update. // Update RTC timer. Called by SNTP module each time it receives an update.
void sntp_update_rtc(time_t t, uint32_t us) { void sntp_update_rtc(time_t t, uint32_t us) {
// Apply daylight and timezone correction // Apply daylight and timezone correction
t += (stz.tz_minuteswest + stz.tz_dsttime * 60) * 60; t += (stz.tz_minuteswest + stz.tz_dsttime * 60) * 60;
// DEBUG: Compute and print drift int64_t sntp_correct = (uint64_t)us + (uint64_t)t * 1000000U;
int64_t sntp_current = sntp_base + TIMER_COUNT - tim_ref;
int64_t sntp_correct = (((uint64_t)us + (uint64_t)t * 1000000U)<<12) / cal;
printf("\nRTC Adjust: drift = %ld ticks, cal = %d\n", (time_t)(sntp_correct - sntp_current), cal);
tim_ref = TIMER_COUNT; xSemaphoreTake(sntp_sem, portMAX_DELAY);
cal = sdk_system_rtc_clock_cali_proc(); uint32_t tim = TIMER_COUNT;
// Assume the difference does not overflow in which case
// wrapping of the RTC timer still yields a good difference.
uint32_t diff = tim - tim_ref;
tim_ref = tim;
uint64_t diff_us = ((uint64_t)diff * cal) >> 12;
uint64_t sntp_current = sntp_base + diff_us;
sntp_base = sntp_correct;
cal = sdk_system_rtc_clock_cali_proc();
xSemaphoreGive(sntp_sem);
sntp_base = (((uint64_t)us + (uint64_t)t * 1000000U)<<12) / cal; printf("\nRTC Adjust: drift = %d usec, cal = %d\n", (int)(sntp_correct - sntp_current), cal);
} }