[PATCH v3 6/6] rtc: zynqmp: use dynamic max and min offset ranges
From: Tomas Melin <hidden>
Date: 2026-01-19 09:52:13
Also in:
linux-rtc, lkml
Subsystem:
real time clock (rtc) subsystem, the rest · Maintainers:
Alexandre Belloni, Linus Torvalds
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 <redacted> Tested-by: Harini T <redacted> Signed-off-by: Tomas Melin <redacted> --- drivers/rtc/rtc-zynqmp.c | 8 +++----- 1 file changed, 3 insertions(+), 5 deletions(-)
diff --git a/drivers/rtc/rtc-zynqmp.c b/drivers/rtc/rtc-zynqmp.c
index 1bc957b3a9058aa1d809696c13662ecef0437a92..8fc2f838707c32297e812ef1b8a195ff55f849e3 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 1000000000LL -#define RTC_MIN_OFFSET -32768000 -#define RTC_MAX_OFFSET 32767000 struct xlnx_rtc_dev { struct rtc_device *rtc;
@@ -215,12 +213,12 @@ static int xlnx_rtc_set_offset(struct device *dev, long offset) /* Tick to offset multiplier */ tick_mult = DIV_ROUND_CLOSEST(RTC_PPB, xrtcdev->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