linux-kernel - [PATCH v6 11/18] clk: qcom: krait-cc: force sec

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Date:   Tue, 22 Mar 2022 00:15:41 +0100
From:   Ansuel Smith <ansuelsmth@...il.com>
To:     Rob Herring <robh+dt@...nel.org>,
        Bjorn Andersson <bjorn.andersson@...aro.org>,
        Andy Gross <agross@...nel.org>,
        Michael Turquette <mturquette@...libre.com>,
        Stephen Boyd <sboyd@...nel.org>,
        Ansuel Smith <ansuelsmth@...il.com>,
        devicetree@...r.kernel.org, linux-kernel@...r.kernel.org,
        linux-arm-msm@...r.kernel.org, linux-clk@...r.kernel.org
Subject: [PATCH v6 11/18] clk: qcom: krait-cc: force sec_mux to QSB

Now that we have converted every driver to parent_data, it was
notice that the bootloader can't really leave the system in a
strange state where l2 or the cpu0/1 can be sourced in a number of ways
for example cpu1 sourcing out of qsb, l2 sourcing out of pxo.
To correctly reset the mux and the HFPLL force the sec_mux to QSB.

Signed-off-by: Ansuel Smith <ansuelsmth@...il.com>
---
 drivers/clk/qcom/krait-cc.c | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/drivers/clk/qcom/krait-cc.c b/drivers/clk/qcom/krait-cc.c
index 5f98ee1c3681..299eb4c81d96 100644
--- a/drivers/clk/qcom/krait-cc.c
+++ b/drivers/clk/qcom/krait-cc.c
@@ -15,6 +15,8 @@
 
 #include "clk-krait.h"
 
+#define QSB_RATE	1
+
 static unsigned int sec_mux_map[] = {
 	2,
 	0,
@@ -181,6 +183,13 @@ krait_add_sec_mux(struct device *dev, struct clk *qsb, int id,
 	if (ret)
 		clk = ERR_PTR(ret);
 
+	/*
+	 * Force the sec_mux to be set to QSB rate.
+	 * This is needed to correctly set the parents and
+	 * to later reset mux and HFPLL to a known freq.
+	 */
+	clk_set_rate(clk, QSB_RATE);
+
 err_clk:
 	if (unique_aux)
 		kfree(parent_name);
@@ -378,7 +387,7 @@ static int krait_cc_probe(struct platform_device *pdev)
 	 */
 	cur_rate = clk_get_rate(l2_pri_mux_clk);
 	aux_rate = 384000000;
-	if (cur_rate == 1) {
+	if (cur_rate == QSB_RATE) {
 		dev_info(dev, "L2 @ QSB rate. Forcing new rate.\n");
 		cur_rate = aux_rate;
 	}
@@ -389,7 +398,7 @@ static int krait_cc_probe(struct platform_device *pdev)
 	for_each_possible_cpu(cpu) {
 		clk = clks[cpu];
 		cur_rate = clk_get_rate(clk);
-		if (cur_rate == 1) {
+		if (cur_rate == QSB_RATE) {
 			dev_info(dev, "CPU%d @ QSB rate. Forcing new rate.\n", cpu);
 			cur_rate = aux_rate;
 		}
-- 
2.34.1