[PATCH] clk: mvebu: armada-37xx-periph: Fix initialization for cpu clocks

[Gregory CLEMENT]

The clock parenting was not setup properly when DVFS was enabled. It was
expected that the same clock source was used with and without DVFS which
was not the case.

This patch fixes this issue, allowing to make the cpufreq support work
when the CPU clocks source are not the default ones.

Fixes: 92ce45fb875d ("cpufreq: Add DVFS support for Armada 37xx")
Cc: <stable@xxxxxxxxxxxxxxx>
Reported-by: Christian Neubert <christian.neubert.86@xxxxxxxxx>
Reported-by: Ilias Apalodimas <ilias.apalodimas@xxxxxxxxxx>
Signed-off-by: Gregory CLEMENT <gregory.clement@xxxxxxxxxxx>
---
 drivers/clk/mvebu/armada-37xx-periph.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/drivers/clk/mvebu/armada-37xx-periph.c b/drivers/clk/mvebu/armada-37xx-periph.c
index 1f1cff428d78..26ed3c18a239 100644
--- a/drivers/clk/mvebu/armada-37xx-periph.c
+++ b/drivers/clk/mvebu/armada-37xx-periph.c
@@ -671,6 +671,17 @@ static int armada_3700_add_composite_clk(const struct clk_periph_data *data,
 		map = syscon_regmap_lookup_by_compatible(
 				"marvell,armada-3700-nb-pm");
 		pmcpu_clk->nb_pm_base = map;
+
+		/*
+		 * Use the same parent when DVFS is enabled that the
+		 * default parent received at boot time. When this
+		 * function is called, DVFS is not enabled yet, so we
+		 * get the default parent and we can set the parent
+		 * for DVFS.
+		 */
+		if (clk_pm_cpu_set_parent(muxrate_hw,
+					  clk_pm_cpu_get_parent(muxrate_hw)))
+			dev_warn(dev, "Failed to setup default parent clock for DVFS\n");
 	}
 
 	*hw = clk_hw_register_composite(dev, data->name, data->parent_names,
-- 
2.20.1