diff --git a/drivers/ptp/ptp_idt82p33.c b/drivers/ptp/ptp_idt82p33.c
index afc76c22271a..057190b9cd3d 100644
--- a/drivers/ptp/ptp_idt82p33.c
+++ b/drivers/ptp/ptp_idt82p33.c
@@ -978,24 +978,23 @@ static int idt82p33_enable(struct ptp_clock_info *ptp,
 	return err;
 }
 
+static s32 idt82p33_getmaxphase(__always_unused struct ptp_clock_info *ptp)
+{
+	return WRITE_PHASE_OFFSET_LIMIT;
+}
+
 static int idt82p33_adjwritephase(struct ptp_clock_info *ptp, s32 offset_ns)
 {
 	struct idt82p33_channel *channel =
 		container_of(ptp, struct idt82p33_channel, caps);
 	struct idt82p33 *idt82p33 = channel->idt82p33;
-	s64 offset_regval, offset_fs;
+	s64 offset_regval;
 	u8 val[4] = {0};
 	int err;
 
-	offset_fs = (s64)(-offset_ns) * 1000000;
-
-	if (offset_fs > WRITE_PHASE_OFFSET_LIMIT)
-		offset_fs = WRITE_PHASE_OFFSET_LIMIT;
-	else if (offset_fs < -WRITE_PHASE_OFFSET_LIMIT)
-		offset_fs = -WRITE_PHASE_OFFSET_LIMIT;
-
 	/* Convert from phaseoffset_fs to register value */
-	offset_regval = div_s64(offset_fs * 1000, IDT_T0DPLL_PHASE_RESOL);
+	offset_regval = div_s64((s64)(-offset_ns) * 1000000000ll,
+				IDT_T0DPLL_PHASE_RESOL);
 
 	val[0] = offset_regval & 0xFF;
 	val[1] = (offset_regval >> 8) & 0xFF;
@@ -1175,6 +1174,7 @@ static void idt82p33_caps_init(u32 index, struct ptp_clock_info *caps,
 	caps->n_ext_ts = MAX_PHC_PLL,
 	caps->n_pins = max_pins,
 	caps->adjphase = idt82p33_adjwritephase,
+	caps->getmaxphase = idt82p33_getmaxphase,
 	caps->adjfine = idt82p33_adjfine;
 	caps->adjtime = idt82p33_adjtime;
 	caps->gettime64 = idt82p33_gettime;
diff --git a/drivers/ptp/ptp_idt82p33.h b/drivers/ptp/ptp_idt82p33.h
index 8fcb0b17d207..6a63c14b6966 100644
--- a/drivers/ptp/ptp_idt82p33.h
+++ b/drivers/ptp/ptp_idt82p33.h
@@ -43,9 +43,9 @@
 #define DEFAULT_OUTPUT_MASK_PLL1	DEFAULT_OUTPUT_MASK_PLL0
 
 /**
- * @brief Maximum absolute value for write phase offset in femtoseconds
+ * @brief Maximum absolute value for write phase offset in nanoseconds
  */
-#define WRITE_PHASE_OFFSET_LIMIT (20000052084ll)
+#define WRITE_PHASE_OFFSET_LIMIT (20000l)
 
 /** @brief Phase offset resolution
  *