From: Luo Jie <jie.luo@oss.qualcomm.com>
Date: Tue, 06 Jan 2026 21:35:10 -0800
Subject: [PATCH v2 1/5] clk: qcom: cmnpll: Account for reference clock divider

The clk_cmn_pll_recalc_rate() function must account for the reference clock
divider programmed in CMN_PLL_REFCLK_CONFIG. Without this fix, platforms
with a reference divider other than 1 calculate incorrect CMN PLL rates.
For example, on IPQ5332 where the reference divider is 2, the computed rate
becomes twice the actual output.

Read CMN_PLL_REFCLK_DIV and divide the parent rate by this value before
applying the 2 * FACTOR scaling. This yields the correct rate calculation:
rate = (parent_rate / ref_div) * 2 * factor.

Maintain backward compatibility with earlier platforms (e.g. IPQ9574,
IPQ5424, IPQ5018) that use ref_div = 1.

Fixes: f81715a4c87c ("clk: qcom: Add CMN PLL clock controller driver for IPQ SoC")
Signed-off-by: Luo Jie <jie.luo@oss.qualcomm.com>
--- a/drivers/clk/qcom/ipq-cmn-pll.c
+++ b/drivers/clk/qcom/ipq-cmn-pll.c
@@ -186,7 +186,7 @@ static unsigned long clk_cmn_pll_recalc_
 					     unsigned long parent_rate)
 {
 	struct clk_cmn_pll *cmn_pll = to_clk_cmn_pll(hw);
-	u32 val, factor;
+	u32 val, factor, ref_div;
 
 	/*
 	 * The value of CMN_PLL_DIVIDER_CTRL_FACTOR is automatically adjusted
@@ -194,8 +194,15 @@ static unsigned long clk_cmn_pll_recalc_
 	 */
 	regmap_read(cmn_pll->regmap, CMN_PLL_DIVIDER_CTRL, &val);
 	factor = FIELD_GET(CMN_PLL_DIVIDER_CTRL_FACTOR, val);
+	if (WARN_ON(factor == 0))
+		factor = 1;
 
-	return parent_rate * 2 * factor;
+	regmap_read(cmn_pll->regmap, CMN_PLL_REFCLK_CONFIG, &val);
+	ref_div = FIELD_GET(CMN_PLL_REFCLK_DIV, val);
+	if (WARN_ON(ref_div == 0))
+		ref_div = 1;
+
+	return div_u64((u64)parent_rate * 2 * factor, ref_div);
 }
 
 static int clk_cmn_pll_determine_rate(struct clk_hw *hw,
