From: Linus Torvalds Date: Sun, 20 Dec 2020 18:12:06 +0000 (-0800) Subject: Merge tag 'rtc-5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux X-Git-Tag: v5.11-rc1~51 X-Git-Url: https://repo.jachan.dev/linux.git/commitdiff_plain/f4a2f7866faaf89ea1595b136e01fcb336b46aab Merge tag 'rtc-5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux Pull RTC updates from Alexandre Belloni: "Subsystem: - Remove nvram ABI. There was no complaints about the deprecation for the last 3 years. - Improve RTC device allocation and registration - Now available for ARCH=um Drivers: - at91rm9200: correction and sam9x60 support - ds1307: improve ACPI support - mxc: now DT only - pcf2127: watchdog support now needs the reset-source property - pcf8523: set range - rx6110: i2c support" * tag 'rtc-5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux: (43 commits) rtc: pcf2127: only use watchdog when explicitly available dt-bindings: rtc: add reset-source property rtc: fix RTC removal rtc: s3c: Remove dead code related to periodic tick handling rtc: s3c: Disable all enable (RTC, tick) bits in the probe rtc: ep93xx: Fix NULL pointer dereference in ep93xx_rtc_read_time rtc: test: remove debug message rtc: mxc{,_v2}: enable COMPILE_TEST rtc: enable RTC framework on ARCH=um rtc: pcf8523: use BIT rtc: pcf8523: set range rtc: pcf8523: switch to devm_rtc_allocate_device rtc: destroy mutex when releasing the device rtc: shrink devm_rtc_allocate_device() rtc: rework rtc_register_device() resource management rtc: nvmem: emit an error message when nvmem registration fails rtc: add devm_ prefix to rtc_nvmem_register() rtc: nvmem: remove nvram ABI Documentation: list RTC devres helpers in devres.rst rtc: omap: use devm_pinctrl_register() ... --- f4a2f7866faaf89ea1595b136e01fcb336b46aab diff --cc drivers/rtc/rtc-cmos.c index c5bcd2adc9fe,83415600185c..51e80bc70d42 --- a/drivers/rtc/rtc-cmos.c +++ b/drivers/rtc/rtc-cmos.c @@@ -868,13 -867,9 +867,12 @@@ cmos_do_probe(struct device *dev, struc 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" : diff --cc include/linux/rtc.h index b829382de6c3,55e7beed066c..568909449c13 --- a/include/linux/rtc.h +++ b/include/linux/rtc.h @@@ -110,43 -110,14 +110,37 @@@ struct rtc_device /* 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; @@@ -227,8 -199,41 +221,8 @@@ static inline bool is_leap_year(unsigne 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;