1 // SPDX-License-Identifier: GPL-2.0-only
3  * PSCI CPU idle driver.
28 #include "cpuidle-psci.h"
59 	u32 *states = data->psci_states;  in psci_enter_domain_idle_state()  local
60 	struct device *pd_dev = data->dev;  in psci_enter_domain_idle_state()
66 		return -1;  in psci_enter_domain_idle_state()
68 	/* Do runtime PM to manage a hierarchical CPU toplogy. */  in psci_enter_domain_idle_state()
73 		state = states[idx];  in psci_enter_domain_idle_state()
75 	ret = psci_cpu_suspend_enter(state) ? -1 : idx;  in psci_enter_domain_idle_state()
81 	/* Clear the domain state to start fresh when back from idle. */  in psci_enter_domain_idle_state()
86 static int psci_idle_cpuhp_up(unsigned int cpu)  in psci_idle_cpuhp_up()  argument
96 static int psci_idle_cpuhp_down(unsigned int cpu)  in psci_idle_cpuhp_down()  argument
133 	{ .compatible = "arm,idle-state",
140 	int err = of_property_read_u32(np, "arm,psci-suspend-param", state);  in psci_dt_parse_state_node()
143 		pr_warn("%pOF missing arm,psci-suspend-param property\n", np);  in psci_dt_parse_state_node()
149 		return -EINVAL;  in psci_dt_parse_state_node()
157 				     unsigned int state_count, int cpu)  in psci_dt_cpu_init_topology()  argument
163 	data->dev = psci_dt_attach_cpu(cpu);  in psci_dt_cpu_init_topology()
164 	if (IS_ERR_OR_NULL(data->dev))  in psci_dt_cpu_init_topology()
165 		return PTR_ERR_OR_ZERO(data->dev);  in psci_dt_cpu_init_topology()
168 	 * Using the deepest state for the CPU to trigger a potential selection  in psci_dt_cpu_init_topology()
169 	 * of a shared state for the domain, assumes the domain states are all  in psci_dt_cpu_init_topology()
170 	 * deeper states.  in psci_dt_cpu_init_topology()
172 	drv->states[state_count - 1].enter = psci_enter_domain_idle_state;  in psci_dt_cpu_init_topology()
180 				 unsigned int state_count, int cpu)  in psci_dt_cpu_init_idle()  argument
185 	struct psci_cpuidle_data *data = per_cpu_ptr(&psci_cpuidle_data, cpu);  in psci_dt_cpu_init_idle()
191 		return -ENOMEM;  in psci_dt_cpu_init_idle()
194 		state_node = of_get_cpu_state_node(cpu_node, i - 1);  in psci_dt_cpu_init_idle()
204 		pr_debug("psci-power-state %#x index %d\n", psci_states[i], i);  in psci_dt_cpu_init_idle()
208 		return -ENODEV;  in psci_dt_cpu_init_idle()
211 	ret = psci_dt_cpu_init_topology(drv, data, state_count, cpu);  in psci_dt_cpu_init_idle()
215 	/* Idle states parsed correctly, store them in the per-cpu struct. */  in psci_dt_cpu_init_idle()
216 	data->psci_states = psci_states;  in psci_dt_cpu_init_idle()
221 			      unsigned int cpu, unsigned int state_count)  in psci_cpu_init_idle()  argument
228 	 * idle states must not be enabled, so bail out  in psci_cpu_init_idle()
231 		return -EOPNOTSUPP;  in psci_cpu_init_idle()
233 	cpu_node = of_cpu_device_node_get(cpu);  in psci_cpu_init_idle()
235 		return -ENODEV;  in psci_cpu_init_idle()
237 	ret = psci_dt_cpu_init_idle(dev, drv, cpu_node, state_count, cpu);  in psci_cpu_init_idle()
244 static void psci_cpu_deinit_idle(int cpu)  in psci_cpu_deinit_idle()  argument
246 	struct psci_cpuidle_data *data = per_cpu_ptr(&psci_cpuidle_data, cpu);  in psci_cpu_deinit_idle()
248 	psci_dt_detach_cpu(data->dev);  in psci_cpu_deinit_idle()
252 static int psci_idle_init_cpu(struct device *dev, int cpu)  in psci_idle_init_cpu()  argument
259 	cpu_node = of_cpu_device_node_get(cpu);  in psci_idle_init_cpu()
261 		return -ENODEV;  in psci_idle_init_cpu()
264 	 * Check whether the enable-method for the cpu is PSCI, fail  in psci_idle_init_cpu()
267 	enable_method = of_get_property(cpu_node, "enable-method", NULL);  in psci_idle_init_cpu()
269 		ret = -ENODEV;  in psci_idle_init_cpu()
277 		return -ENOMEM;  in psci_idle_init_cpu()
279 	drv->name = "psci_idle";  in psci_idle_init_cpu()
280 	drv->owner = THIS_MODULE;  in psci_idle_init_cpu()
281 	drv->cpumask = (struct cpumask *)cpumask_of(cpu);  in psci_idle_init_cpu()
284 	 * PSCI idle states relies on architectural WFI to be represented as  in psci_idle_init_cpu()
287 	drv->states[0].enter = psci_enter_idle_state;  in psci_idle_init_cpu()
288 	drv->states[0].exit_latency = 1;  in psci_idle_init_cpu()
289 	drv->states[0].target_residency = 1;  in psci_idle_init_cpu()
290 	drv->states[0].power_usage = UINT_MAX;  in psci_idle_init_cpu()
291 	strcpy(drv->states[0].name, "WFI");  in psci_idle_init_cpu()
292 	strcpy(drv->states[0].desc, "ARM WFI");  in psci_idle_init_cpu()
295 	 * If no DT idle states are detected (ret == 0) let the driver  in psci_idle_init_cpu()
297 	 * initialize the idle driver if only wfi is supported, the  in psci_idle_init_cpu()
298 	 * default archictectural back-end already executes wfi  in psci_idle_init_cpu()
299 	 * on idle entry.  in psci_idle_init_cpu()
303 		return ret ? : -ENODEV;  in psci_idle_init_cpu()
306 	 * Initialize PSCI idle states.  in psci_idle_init_cpu()
308 	ret = psci_cpu_init_idle(dev, drv, cpu, ret);  in psci_idle_init_cpu()
310 		pr_err("CPU %d failed to PSCI idle\n", cpu);  in psci_idle_init_cpu()
322 	psci_cpu_deinit_idle(cpu);  in psci_idle_init_cpu()
327  * psci_idle_probe - Initializes PSCI cpuidle driver
329  * Initializes PSCI cpuidle driver for all CPUs, if any CPU fails
335 	int cpu, ret;  in psci_cpuidle_probe()  local
339 	for_each_possible_cpu(cpu) {  in psci_cpuidle_probe()
340 		ret = psci_idle_init_cpu(&pdev->dev, cpu);  in psci_cpuidle_probe()
349 	while (--cpu >= 0) {  in psci_cpuidle_probe()
350 		dev = per_cpu(cpuidle_devices, cpu);  in psci_cpuidle_probe()
353 		psci_cpu_deinit_idle(cpu);  in psci_cpuidle_probe()
362 		.name = "psci-cpuidle",
375 	pdev = platform_device_register_simple("psci-cpuidle", -1, NULL, 0);  in psci_idle_init()