if (retval)
goto cleanup2;
+ /* Set the sync offset for the periodic 11min update correct */
+ cmos_rtc.rtc->set_offset_nsec = NSEC_PER_SEC / 2;
+
/* export at least the first block of NVRAM */
nvmem_cfg.size = address_space - NVRAM_OFFSET;
- if (rtc_nvmem_register(cmos_rtc.rtc, &nvmem_cfg))
- dev_err(dev, "nvmem registration failed\n");
+ devm_rtc_nvmem_register(cmos_rtc.rtc, &nvmem_cfg);
dev_info(dev, "%s%s, %d bytes nvram%s\n",
!is_valid_irq(rtc_irq) ? "no alarms" :
/* Some hardware can't support UIE mode */
int uie_unsupported;
- /* Number of nsec it takes to set the RTC clock. This influences when
- * the set ops are called. An offset:
- * - of 0.5 s will call RTC set for wall clock time 10.0 s at 9.5 s
- * - of 1.5 s will call RTC set for wall clock time 10.0 s at 8.5 s
- * - of -0.5 s will call RTC set for wall clock time 10.0 s at 10.5 s
+ /*
+ * This offset specifies the update timing of the RTC.
+ *
+ * tsched t1 write(t2.tv_sec - 1sec)) t2 RTC increments seconds
+ *
+ * The offset defines how tsched is computed so that the write to
+ * the RTC (t2.tv_sec - 1sec) is correct versus the time required
+ * for the transport of the write and the time which the RTC needs
+ * to increment seconds the first time after the write (t2).
+ *
+ * For direct accessible RTCs tsched ~= t1 because the write time
+ * is negligible. For RTCs behind slow busses the transport time is
+ * significant and has to be taken into account.
+ *
+ * The time between the write (t1) and the first increment after
+ * the write (t2) is RTC specific. For a MC146818 RTC it's 500ms,
+ * for many others it's exactly 1 second. Consult the datasheet.
+ *
+ * The value of this offset is also used to calculate the to be
+ * written value (t2.tv_sec - 1sec) at tsched.
+ *
+ * The default value for this is NSEC_PER_SEC + 10 msec default
+ * transport time. The offset can be adjusted by drivers so the
+ * calculation for the to be written value at tsched becomes
+ * correct:
+ *
+ * newval = tsched + set_offset_nsec - NSEC_PER_SEC
+ * and (tsched + set_offset_nsec) % NSEC_PER_SEC == 0
*/
- long set_offset_nsec;
+ unsigned long set_offset_nsec;
- bool registered;
-
- /* Old ABI support */
- bool nvram_old_abi;
- struct bin_attribute *nvram;
-
time64_t range_min;
timeu64_t range_max;
time64_t start_secs;
return (!(year % 4) && (year % 100)) || !(year % 400);
}
- #define rtc_register_device(device) \
- __rtc_register_device(THIS_MODULE, device)
-/* Determine if we can call to driver to set the time. Drivers can only be
- * called to set a second aligned time value, and the field set_offset_nsec
- * specifies how far away from the second aligned time to call the driver.
- *
- * This also computes 'to_set' which is the time we are trying to set, and has
- * a zero in tv_nsecs, such that:
- * to_set - set_delay_nsec == now +/- FUZZ
- *
- */
-static inline bool rtc_tv_nsec_ok(s64 set_offset_nsec,
- struct timespec64 *to_set,
- const struct timespec64 *now)
-{
- /* Allowed error in tv_nsec, arbitarily set to 5 jiffies in ns. */
- const unsigned long TIME_SET_NSEC_FUZZ = TICK_NSEC * 5;
- struct timespec64 delay = {.tv_sec = 0,
- .tv_nsec = set_offset_nsec};
-
- *to_set = timespec64_add(*now, delay);
-
- if (to_set->tv_nsec < TIME_SET_NSEC_FUZZ) {
- to_set->tv_nsec = 0;
- return true;
- }
-
- if (to_set->tv_nsec > NSEC_PER_SEC - TIME_SET_NSEC_FUZZ) {
- to_set->tv_sec++;
- to_set->tv_nsec = 0;
- return true;
- }
- return false;
-}
-
+ #define devm_rtc_register_device(device) \
+ __devm_rtc_register_device(THIS_MODULE, device)
#ifdef CONFIG_RTC_HCTOSYS_DEVICE
extern int rtc_hctosys_ret;
projects / kernel.git / commitdiff