From f619355a6bc6e2ce8b2b104abfd4f2c86e22aad3 Mon Sep 17 00:00:00 2001
From: Yury Norov <ynorov@nvidia.com>
Date: Fri, 25 Sep 2026 15:38:58 -0400
Subject: [PATCH] clk: si521xx: simplify si521xx_diff_idx_to_reg_bit()

Switch the function to using fns(), and get rid of the double for-loop.

Signed-off-by: Yury Norov <ynorov@nvidia.com>
Signed-off-by: Brian Masney <bmasney@redhat.com>
---
 drivers/clk/clk-si521xx.c | 29 ++++++++++++++++++-----------
 1 file changed, 18 insertions(+), 11 deletions(-)

diff --git a/drivers/clk/clk-si521xx.c b/drivers/clk/clk-si521xx.c
index 6e3c8e6ccc8d..23d80f060f99 100644
--- a/drivers/clk/clk-si521xx.c
+++ b/drivers/clk/clk-si521xx.c
@@ -13,6 +13,7 @@
  */
 
 #include <linux/bitfield.h>
+#include <linux/bitops.h>
 #include <linux/bitrev.h>
 #include <linux/clk-provider.h>
 #include <linux/i2c.h>
@@ -255,18 +256,24 @@ static void si521xx_diff_idx_to_reg_bit(const u16 chip_info, const int idx,
 					struct si_clk *clk)
 {
 	unsigned long mask;
-	int oe, b, ctr = 0;
+	unsigned int bit;
+	int oe = 1;
 
-	for (oe = 1; oe <= 2; oe++) {
-		mask = bitrev8(SI521XX_OE_MAP_GET_OE(oe, chip_info));
-		for_each_set_bit(b, &mask, 8) {
-			if (ctr++ != idx)
-				continue;
-			clk->reg = SI521XX_REG_OE(oe);
-			clk->bit = 7 - b;
-			return;
-		}
-	}
+	mask = bitrev8(SI521XX_OE_MAP_GET_OE(1, chip_info));
+	bit = fns(mask, idx);
+	if (bit < 8)
+		goto out;
+
+	oe = 2;
+	bit = idx - hweight8(mask);
+	mask = bitrev8(SI521XX_OE_MAP_GET_OE(2, chip_info));
+	bit = fns(mask, bit);
+	if (bit >= 8)
+		return;
+
+out:
+	clk->reg = SI521XX_REG_OE(oe);
+	clk->bit = 7 - bit;
 }
 
 static struct clk_hw *