drivers/cpuidle/cpuidle-arm.c

1 // SPDX-License-Identifier: GPL-2.0-only
3  * ARM/ARM64 generic CPU idle driver.
25  * arm_enter_idle_state - Programs CPU to enter the specified state
31  * Called from the CPUidle framework to program the device to the
38 	 * Pass idle state index to arm_cpuidle_suspend which in turn  in arm_enter_idle_state()
39 	 * will call the CPU ops suspend protocol with idle index as a  in arm_enter_idle_state()
52 	 * to work around this issue and allow installing a special
53 	 * handler for idle state index 0.
66 	{ .compatible = "arm,idle-state",
75  * framework. It relies on core code to parse the idle states
85 		return -ENOMEM;  in arm_idle_init_cpu()
87 	drv->cpumask = (struct cpumask *)cpumask_of(cpu);  in arm_idle_init_cpu()
90 	 * Initialize idle states data, starting at index 1.  This  in arm_idle_init_cpu()
91 	 * driver is DT only, if no DT idle states are detected (ret  in arm_idle_init_cpu()
93 	 * there is no reason to initialize the idle driver if only  in arm_idle_init_cpu()
98 		ret = ret ? : -ENODEV;  in arm_idle_init_cpu()
103 	 * Call arch CPU operations in order to initialize  in arm_idle_init_cpu()
104 	 * idle states suspend back-end specific data  in arm_idle_init_cpu()
109 	 * Allow the initialization to continue for other CPUs, if the  in arm_idle_init_cpu()
110 	 * reported failure is a HW misconfiguration/breakage (-ENXIO).  in arm_idle_init_cpu()
112 	 * Some platforms do not support idle operations  in arm_idle_init_cpu()
113 	 * (arm_cpuidle_init() returning -EOPNOTSUPP), we should  in arm_idle_init_cpu()
118 		if (ret != -EOPNOTSUPP)  in arm_idle_init_cpu()
119 			pr_err("CPU %d failed to init idle CPU ops\n", cpu);  in arm_idle_init_cpu()
120 		ret = ret == -ENXIO ? 0 : ret;  in arm_idle_init_cpu()
138  * arm_idle_init - Initializes arm cpuidle driver
141  * to register cpuidle driver then rollback to cancel all CPUs
159 	while (--cpu >= 0) {  in arm_idle_init()