openwrt/target/linux/ipq806x/patches-6.6/122-01-clk-qcom-krait-cc-handle-qsb-clock-defined-in-DTS.patch

From 666c1b745e93ccddde841d5057c33f97b29a316a Mon Sep 17 00:00:00 2001
From: Christian Marangi <[email protected]>
Date: Thu, 15 Sep 2022 02:19:28 +0200
Subject: [PATCH 3/9] clk: qcom: krait-cc: handle qsb clock defined in DTS

qsb fixed clk may be defined in DTS and correctly passed in the clocks
list. Add related code to handle this and modify the logic to
dynamically read qsb clock frequency.

Signed-off-by: Christian Marangi <[email protected]>
---
 drivers/clk/qcom/krait-cc.c | 14 +++++++++++---
 1 file changed, 11 insertions(+), 3 deletions(-)

--- a/drivers/clk/qcom/krait-cc.c
+++ b/drivers/clk/qcom/krait-cc.c
@@ -348,7 +348,7 @@ static int krait_cc_probe(struct platfor
 {
 	struct device *dev = &pdev->dev;
 	const struct of_device_id *id;
-	unsigned long cur_rate, aux_rate;
+	unsigned long cur_rate, aux_rate, qsb_rate;
 	int cpu;
 	struct clk_hw *mux, *l2_pri_mux;
 	struct clk *clk, **clks;
@@ -357,11 +357,19 @@ static int krait_cc_probe(struct platfor
 	if (!id)
 		return -ENODEV;
 
-	/* Rate is 1 because 0 causes problems for __clk_mux_determine_rate */
-	clk = clk_register_fixed_rate(dev, "qsb", NULL, 0, 1);
+	/*
+	 * Per Documentation qsb should be provided from DTS.
+	 * To address old implementation, register the fixed clock anyway.
+	 * Rate is 1 because 0 causes problems for __clk_mux_determine_rate
+	 */
+	clk = clk_get(dev, "qsb");
+	if (IS_ERR(clk))
+		clk = clk_register_fixed_rate(dev, "qsb", NULL, 0, 1);
 	if (IS_ERR(clk))
 		return PTR_ERR(clk);
 
+	qsb_rate = clk_get_rate(clk);
+
 	if (!id->data) {
 		clk = clk_register_fixed_factor(dev, "acpu_aux",
 						"gpll0_vote", 0, 1, 2);