From: Paul Cercueil paul@crapouillou.net
[ Upstream commit 71f8817c28e2e1e5549138e2aef68c2fd784e162 ]
Make sure that the PLL that feeds the CPU won't be stopped while the kernel is running.
This fixes a problem on JZ4760 (and probably others) where under very specific conditions, the main PLL would be turned OFF when the kernel was shutting down, causing the shutdown process to fail.
Signed-off-by: Paul Cercueil paul@crapouillou.net Signed-off-by: Thomas Bogendoerfer tsbogend@alpha.franken.de Signed-off-by: Sasha Levin sashal@kernel.org --- arch/mips/generic/board-ingenic.c | 28 ++++++++++++++++++++++++++++ 1 file changed, 28 insertions(+)
diff --git a/arch/mips/generic/board-ingenic.c b/arch/mips/generic/board-ingenic.c index 0cec0bea13d6..11387a93867b 100644 --- a/arch/mips/generic/board-ingenic.c +++ b/arch/mips/generic/board-ingenic.c @@ -7,6 +7,8 @@ * Copyright (C) 2020 Paul Cercueil paul@crapouillou.net */
+#include <linux/clk.h> +#include <linux/of.h> #include <linux/of_address.h> #include <linux/of_fdt.h> #include <linux/pm.h> @@ -108,10 +110,36 @@ static const struct platform_suspend_ops ingenic_pm_ops __maybe_unused = {
static int __init ingenic_pm_init(void) { + struct device_node *cpu_node; + struct clk *cpu0_clk; + int ret; + if (boot_cpu_type() == CPU_XBURST) { if (IS_ENABLED(CONFIG_PM_SLEEP)) suspend_set_ops(&ingenic_pm_ops); _machine_halt = ingenic_halt; + + /* + * Unconditionally enable the clock for the first CPU. + * This makes sure that the PLL that feeds the CPU won't be + * stopped while the kernel is running. + */ + cpu_node = of_get_cpu_node(0, NULL); + if (!cpu_node) { + pr_err("Unable to get CPU node\n"); + } else { + cpu0_clk = of_clk_get(cpu_node, 0); + if (IS_ERR(cpu0_clk)) { + pr_err("Unable to get CPU0 clock\n"); + return PTR_ERR(cpu0_clk); + } + + ret = clk_prepare_enable(cpu0_clk); + if (ret) { + pr_err("Unable to enable CPU0 clock\n"); + return ret; + } + } }
return 0;