arm/kernel/cpuidle.c

1 // SPDX-License-Identifier: GPL-2.0-or-later
18  * arm_cpuidle_simple_enter() - a wrapper to cpu_do_idle()
23  * A trivial wrapper to allow the cpu_do_idle function to be assigned as a
37  * arm_cpuidle_suspend() - function to enter low power idle states
43  * Returns the result of the suspend callback.
49 	return cpuidle_ops[cpu].suspend(index);  in arm_cpuidle_suspend()
53  * arm_cpuidle_get_ops() - find a registered cpuidle_ops by name
65 	for (; m->method; m++)  in arm_cpuidle_get_ops()
66 		if (!strcmp(m->method, method))  in arm_cpuidle_get_ops()
67 			return m->ops;  in arm_cpuidle_get_ops()
73  * arm_cpuidle_read_ops() - Initialize the cpuidle ops with the device tree
74  * @dn: a pointer to a struct device node corresponding to a cpu node
77  * Get the method name defined in the 'enable-method' property, retrieve the
82  * Return 0 on sucess, -ENOENT if no 'enable-method' is defined, -EOPNOTSUPP if
83  * no cpuidle_ops is registered for the 'enable-method', or if either init or
84  * suspend callback isn't defined.
91 	enable_method = of_get_property(dn, "enable-method", NULL);  in arm_cpuidle_read_ops()
93 		return -ENOENT;  in arm_cpuidle_read_ops()
97 		pr_warn("%pOF: unsupported enable-method property: %s\n",  in arm_cpuidle_read_ops()
99 		return -EOPNOTSUPP;  in arm_cpuidle_read_ops()
102 	if (!ops->init || !ops->suspend) {  in arm_cpuidle_read_ops()
103 		pr_warn("cpuidle_ops '%s': no init or suspend callback\n",  in arm_cpuidle_read_ops()
105 		return -EOPNOTSUPP;  in arm_cpuidle_read_ops()
110 	pr_notice("cpuidle: enable-method property '%s'"  in arm_cpuidle_read_ops()
117  * arm_cpuidle_init() - Initialize cpuidle_ops for a specific cpu
118  * @cpu: the cpu to be initialized
121  * the cpu's idle initialization callback. This may fail if the underlying HW
126  *  -ENODEV if it fails to find the cpu node in the device tree,
127  *  -EOPNOTSUPP if it does not find a registered and valid cpuidle_ops for
129  *  -ENOENT if it fails to find an 'enable-method' property,
130  *  -ENXIO if the HW reports a failure or a misconfiguration,
131  *  -ENOMEM if the HW report an memory allocation failure
139 		return -ENODEV;  in arm_cpuidle_init()