clk: sunxi-ng: a33: gate then ungate PLL CPU clk after rate change

This patch utilizes the new PLL clk notifier to gate then ungate the
PLL CPU clock after rate changes. This should mitigate the system
hangs observed after the introduction of cpufreq for the A33.

Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Tested-by: Quentin Schulz <quentin.schulz@free-electrons.com>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
diff --git a/drivers/clk/sunxi-ng/ccu-sun8i-a33.c b/drivers/clk/sunxi-ng/ccu-sun8i-a33.c
index a7b3c08..2c69b63 100644
--- a/drivers/clk/sunxi-ng/ccu-sun8i-a33.c
+++ b/drivers/clk/sunxi-ng/ccu-sun8i-a33.c
@@ -752,6 +752,13 @@
 	.num_resets	= ARRAY_SIZE(sun8i_a33_ccu_resets),
 };
 
+static struct ccu_pll_nb sun8i_a33_pll_cpu_nb = {
+	.common	= &pll_cpux_clk.common,
+	/* copy from pll_cpux_clk */
+	.enable	= BIT(31),
+	.lock	= BIT(28),
+};
+
 static struct ccu_mux_nb sun8i_a33_cpu_nb = {
 	.common		= &cpux_clk.common,
 	.cm		= &cpux_clk.mux,
@@ -783,6 +790,10 @@
 
 	sunxi_ccu_probe(node, reg, &sun8i_a33_ccu_desc);
 
+	/* Gate then ungate PLL CPU after any rate changes */
+	ccu_pll_notifier_register(&sun8i_a33_pll_cpu_nb);
+
+	/* Reparent CPU during PLL CPU rate changes */
 	ccu_mux_notifier_register(pll_cpux_clk.common.hw.clk,
 				  &sun8i_a33_cpu_nb);
 }