From: Icenowy Zheng icenowy@aosc.xyz
[ Upstream commit 790d929b540661945d1c70652ffb602c5c06ad85 ]
When adjusting PLL_CPUX on A33, the PLL is temporarily driven too high, and the system hangs.
Add a notifier to avoid this situation by temporarily switching to a known stable 24 MHz oscillator.
Signed-off-by: Icenowy Zheng icenowy@aosc.xyz Signed-off-by: Maxime Ripard maxime.ripard@free-electrons.com Signed-off-by: Sasha Levin alexander.levin@verizon.com --- drivers/clk/sunxi-ng/ccu-sun8i-a33.c | 10 ++++++++++ 1 file changed, 10 insertions(+)
diff --git a/drivers/clk/sunxi-ng/ccu-sun8i-a33.c b/drivers/clk/sunxi-ng/ccu-sun8i-a33.c index 9bd1f78a0547..e1dc4e5b34e1 100644 --- a/drivers/clk/sunxi-ng/ccu-sun8i-a33.c +++ b/drivers/clk/sunxi-ng/ccu-sun8i-a33.c @@ -752,6 +752,13 @@ static const struct sunxi_ccu_desc sun8i_a33_ccu_desc = { .num_resets = ARRAY_SIZE(sun8i_a33_ccu_resets), };
+static struct ccu_mux_nb sun8i_a33_cpu_nb = { + .common = &cpux_clk.common, + .cm = &cpux_clk.mux, + .delay_us = 1, /* > 8 clock cycles at 24 MHz */ + .bypass_index = 1, /* index of 24 MHz oscillator */ +}; + static void __init sun8i_a33_ccu_setup(struct device_node *node) { void __iomem *reg; @@ -775,6 +782,9 @@ static void __init sun8i_a33_ccu_setup(struct device_node *node) writel(val, reg + SUN8I_A33_PLL_MIPI_REG);
sunxi_ccu_probe(node, reg, &sun8i_a33_ccu_desc); + + ccu_mux_notifier_register(pll_cpux_clk.common.hw.clk, + &sun8i_a33_cpu_nb); } CLK_OF_DECLARE(sun8i_a33_ccu, "allwinner,sun8i-a33-ccu", sun8i_a33_ccu_setup);