From 2254383176fc9f15ce54eabc849b36c874efd3aa Mon Sep 17 00:00:00 2001 From: Tomas Melin Date: Thu, 22 Jan 2026 13:53:49 +0000 Subject: [PATCH] rtc: zynqmp: use dynamic max and min offset ranges Maximum and minimum offsets in ppb that can be handled are dependent on the rtc clock frequency and what can fit in the 16-bit register field. Reviewed-by: Harini T Tested-by: Harini T Signed-off-by: Tomas Melin Acked-by: Michal Simek Link: https://patch.msgid.link/20260122-zynqmp-rtc-updates-v4-5-d4edb966b499@vaisala.com Signed-off-by: Alexandre Belloni --- drivers/rtc/rtc-zynqmp.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) diff --git a/drivers/rtc/rtc-zynqmp.c b/drivers/rtc/rtc-zynqmp.c index f0f5dc63e254..2ae54804b87a 100644 --- a/drivers/rtc/rtc-zynqmp.c +++ b/drivers/rtc/rtc-zynqmp.c @@ -44,8 +44,6 @@ #define RTC_FR_MASK 0xF0000 #define RTC_FR_MAX_TICKS 16 #define RTC_PPB 1000000000 -#define RTC_MIN_OFFSET -32768000 -#define RTC_MAX_OFFSET 32767000 struct xlnx_rtc_dev { struct rtc_device *rtc; @@ -215,12 +213,13 @@ static int xlnx_rtc_set_offset(struct device *dev, long offset) /* Tick to offset multiplier */ tick_mult = DIV_ROUND_CLOSEST(RTC_PPB, freq); - if (offset < RTC_MIN_OFFSET || offset > RTC_MAX_OFFSET) - return -ERANGE; /* Number ticks for given offset */ max_tick = div_s64_rem(offset, tick_mult, &fract_offset); + if (freq + max_tick > RTC_TICK_MASK || (freq + max_tick < 1)) + return -ERANGE; + /* Number fractional ticks for given offset */ if (fract_offset) { fract_part = DIV_ROUND_UP(tick_mult, RTC_FR_MAX_TICKS); -- 2.47.3