[linux-block.git] / drivers / cpuidle / cpuidle-psci.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * PSCI CPU idle driver.
 *
 * Copyright (C) 2019 ARM Ltd.
 * Author: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
 */

#define pr_fmt(fmt) "CPUidle PSCI: " fmt

#include <linux/cpuhotplug.h>
#include <linux/cpu_cooling.h>
#include <linux/cpuidle.h>
#include <linux/cpumask.h>
#include <linux/cpu_pm.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/platform_device.h>
#include <linux/psci.h>
#include <linux/pm_domain.h>
#include <linux/pm_runtime.h>
#include <linux/slab.h>
#include <linux/string.h>

#include <asm/cpuidle.h>

#include "cpuidle-psci.h"
#include "dt_idle_states.h"

struct psci_cpuidle_data {
	u32 *psci_states;
	struct device *dev;
};

static DEFINE_PER_CPU_READ_MOSTLY(struct psci_cpuidle_data, psci_cpuidle_data);
static DEFINE_PER_CPU(u32, domain_state);
static bool psci_cpuidle_use_cpuhp;

void psci_set_domain_state(u32 state)
{
	__this_cpu_write(domain_state, state);
}

static inline u32 psci_get_domain_state(void)
{
	return __this_cpu_read(domain_state);
}

static inline int psci_enter_state(int idx, u32 state)
{
	return CPU_PM_CPU_IDLE_ENTER_PARAM(psci_cpu_suspend_enter, idx, state);
}

static int __psci_enter_domain_idle_state(struct cpuidle_device *dev,
					  struct cpuidle_driver *drv, int idx,
					  bool s2idle)
{
	struct psci_cpuidle_data *data = this_cpu_ptr(&psci_cpuidle_data);
	u32 *states = data->psci_states;
	struct device *pd_dev = data->dev;
	u32 state;
	int ret;

	ret = cpu_pm_enter();
	if (ret)
		return -1;

	/* Do runtime PM to manage a hierarchical CPU toplogy. */
	rcu_irq_enter_irqson();
	if (s2idle)
		dev_pm_genpd_suspend(pd_dev);
	else
		pm_runtime_put_sync_suspend(pd_dev);
	rcu_irq_exit_irqson();

	state = psci_get_domain_state();
	if (!state)
		state = states[idx];

	ret = psci_cpu_suspend_enter(state) ? -1 : idx;

	rcu_irq_enter_irqson();
	if (s2idle)
		dev_pm_genpd_resume(pd_dev);
	else
		pm_runtime_get_sync(pd_dev);
	rcu_irq_exit_irqson();

	cpu_pm_exit();

	/* Clear the domain state to start fresh when back from idle. */
	psci_set_domain_state(0);
	return ret;
}

static int psci_enter_domain_idle_state(struct cpuidle_device *dev,
					struct cpuidle_driver *drv, int idx)
{
	return __psci_enter_domain_idle_state(dev, drv, idx, false);
}

static int psci_enter_s2idle_domain_idle_state(struct cpuidle_device *dev,
					       struct cpuidle_driver *drv,
					       int idx)
{
	return __psci_enter_domain_idle_state(dev, drv, idx, true);
}

static int psci_idle_cpuhp_up(unsigned int cpu)
{
	struct device *pd_dev = __this_cpu_read(psci_cpuidle_data.dev);

	if (pd_dev)
		pm_runtime_get_sync(pd_dev);

	return 0;
}

static int psci_idle_cpuhp_down(unsigned int cpu)
{
	struct device *pd_dev = __this_cpu_read(psci_cpuidle_data.dev);

	if (pd_dev) {
		pm_runtime_put_sync(pd_dev);
		/* Clear domain state to start fresh at next online. */
		psci_set_domain_state(0);
	}

	return 0;
}

static void psci_idle_init_cpuhp(void)
{
	int err;

	if (!psci_cpuidle_use_cpuhp)
		return;

	err = cpuhp_setup_state_nocalls(CPUHP_AP_CPU_PM_STARTING,
					"cpuidle/psci:online",
					psci_idle_cpuhp_up,
					psci_idle_cpuhp_down);
	if (err)
		pr_warn("Failed %d while setup cpuhp state\n", err);
}

static int psci_enter_idle_state(struct cpuidle_device *dev,
				struct cpuidle_driver *drv, int idx)
{
	u32 *state = __this_cpu_read(psci_cpuidle_data.psci_states);

	return psci_enter_state(idx, state[idx]);
}

static const struct of_device_id psci_idle_state_match[] = {
	{ .compatible = "arm,idle-state",
	  .data = psci_enter_idle_state },
	{ },
};

int psci_dt_parse_state_node(struct device_node *np, u32 *state)
{
	int err = of_property_read_u32(np, "arm,psci-suspend-param", state);

	if (err) {
		pr_warn("%pOF missing arm,psci-suspend-param property\n", np);
		return err;
	}

	if (!psci_power_state_is_valid(*state)) {
		pr_warn("Invalid PSCI power state %#x\n", *state);
		return -EINVAL;
	}

	return 0;
}

static int psci_dt_cpu_init_topology(struct cpuidle_driver *drv,
				     struct psci_cpuidle_data *data,
				     unsigned int state_count, int cpu)
{
	/* Currently limit the hierarchical topology to be used in OSI mode. */
	if (!psci_has_osi_support())
		return 0;

	data->dev = psci_dt_attach_cpu(cpu);
	if (IS_ERR_OR_NULL(data->dev))
		return PTR_ERR_OR_ZERO(data->dev);

	/*
	 * Using the deepest state for the CPU to trigger a potential selection
	 * of a shared state for the domain, assumes the domain states are all
	 * deeper states.
	 */
	drv->states[state_count - 1].enter = psci_enter_domain_idle_state;
	drv->states[state_count - 1].enter_s2idle = psci_enter_s2idle_domain_idle_state;
	psci_cpuidle_use_cpuhp = true;

	return 0;
}

static int psci_dt_cpu_init_idle(struct device *dev, struct cpuidle_driver *drv,
				 struct device_node *cpu_node,
				 unsigned int state_count, int cpu)
{
	int i, ret = 0;
	u32 *psci_states;
	struct device_node *state_node;
	struct psci_cpuidle_data *data = per_cpu_ptr(&psci_cpuidle_data, cpu);

	state_count++; /* Add WFI state too */
	psci_states = devm_kcalloc(dev, state_count, sizeof(*psci_states),
				   GFP_KERNEL);
	if (!psci_states)
		return -ENOMEM;

	for (i = 1; i < state_count; i++) {
		state_node = of_get_cpu_state_node(cpu_node, i - 1);
		if (!state_node)
			break;

		ret = psci_dt_parse_state_node(state_node, &psci_states[i]);
		of_node_put(state_node);

		if (ret)
			return ret;

		pr_debug("psci-power-state %#x index %d\n", psci_states[i], i);
	}

	if (i != state_count)
		return -ENODEV;

	/* Initialize optional data, used for the hierarchical topology. */
	ret = psci_dt_cpu_init_topology(drv, data, state_count, cpu);
	if (ret < 0)
		return ret;

	/* Idle states parsed correctly, store them in the per-cpu struct. */
	data->psci_states = psci_states;
	return 0;
}

static int psci_cpu_init_idle(struct device *dev, struct cpuidle_driver *drv,
			      unsigned int cpu, unsigned int state_count)
{
	struct device_node *cpu_node;
	int ret;

	/*
	 * If the PSCI cpu_suspend function hook has not been initialized
	 * idle states must not be enabled, so bail out
	 */
	if (!psci_ops.cpu_suspend)
		return -EOPNOTSUPP;

	cpu_node = of_cpu_device_node_get(cpu);
	if (!cpu_node)
		return -ENODEV;

	ret = psci_dt_cpu_init_idle(dev, drv, cpu_node, state_count, cpu);

	of_node_put(cpu_node);

	return ret;
}

static void psci_cpu_deinit_idle(int cpu)
{
	struct psci_cpuidle_data *data = per_cpu_ptr(&psci_cpuidle_data, cpu);

	psci_dt_detach_cpu(data->dev);
	psci_cpuidle_use_cpuhp = false;
}

static int psci_idle_init_cpu(struct device *dev, int cpu)
{
	struct cpuidle_driver *drv;
	struct device_node *cpu_node;
	const char *enable_method;
	int ret = 0;

	cpu_node = of_cpu_device_node_get(cpu);
	if (!cpu_node)
		return -ENODEV;

	/*
	 * Check whether the enable-method for the cpu is PSCI, fail
	 * if it is not.
	 */
	enable_method = of_get_property(cpu_node, "enable-method", NULL);
	if (!enable_method || (strcmp(enable_method, "psci")))
		ret = -ENODEV;

	of_node_put(cpu_node);
	if (ret)
		return ret;

	drv = devm_kzalloc(dev, sizeof(*drv), GFP_KERNEL);
	if (!drv)
		return -ENOMEM;

	drv->name = "psci_idle";
	drv->owner = THIS_MODULE;
	drv->cpumask = (struct cpumask *)cpumask_of(cpu);

	/*
	 * PSCI idle states relies on architectural WFI to be represented as
	 * state index 0.
	 */
	drv->states[0].enter = psci_enter_idle_state;
	drv->states[0].exit_latency = 1;
	drv->states[0].target_residency = 1;
	drv->states[0].power_usage = UINT_MAX;
	strcpy(drv->states[0].name, "WFI");
	strcpy(drv->states[0].desc, "ARM WFI");

	/*
	 * If no DT idle states are detected (ret == 0) let the driver
	 * initialization fail accordingly since there is no reason to
	 * initialize the idle driver if only wfi is supported, the
	 * default archictectural back-end already executes wfi
	 * on idle entry.
	 */
	ret = dt_init_idle_driver(drv, psci_idle_state_match, 1);
	if (ret <= 0)
		return ret ? : -ENODEV;

	/*
	 * Initialize PSCI idle states.
	 */
	ret = psci_cpu_init_idle(dev, drv, cpu, ret);
	if (ret) {
		pr_err("CPU %d failed to PSCI idle\n", cpu);
		return ret;
	}

	ret = cpuidle_register(drv, NULL);
	if (ret)
		goto deinit;

	cpuidle_cooling_register(drv);

	return 0;
deinit:
	psci_cpu_deinit_idle(cpu);
	return ret;
}

/*
 * psci_idle_probe - Initializes PSCI cpuidle driver
 *
 * Initializes PSCI cpuidle driver for all CPUs, if any CPU fails
 * to register cpuidle driver then rollback to cancel all CPUs
 * registration.
 */
static int psci_cpuidle_probe(struct platform_device *pdev)
{
	int cpu, ret;
	struct cpuidle_driver *drv;
	struct cpuidle_device *dev;

	for_each_possible_cpu(cpu) {
		ret = psci_idle_init_cpu(&pdev->dev, cpu);
		if (ret)
			goto out_fail;
	}

	psci_idle_init_cpuhp();
	return 0;

out_fail:
	while (--cpu >= 0) {
		dev = per_cpu(cpuidle_devices, cpu);
		drv = cpuidle_get_cpu_driver(dev);
		cpuidle_unregister(drv);
		psci_cpu_deinit_idle(cpu);
	}

	return ret;
}

static struct platform_driver psci_cpuidle_driver = {
	.probe = psci_cpuidle_probe,
	.driver = {
		.name = "psci-cpuidle",
	},
};

static int __init psci_idle_init(void)
{
	struct platform_device *pdev;
	int ret;

	ret = platform_driver_register(&psci_cpuidle_driver);
	if (ret)
		return ret;

	pdev = platform_device_register_simple("psci-cpuidle", -1, NULL, 0);
	if (IS_ERR(pdev)) {
		platform_driver_unregister(&psci_cpuidle_driver);
		return PTR_ERR(pdev);
	}

	return 0;
}
device_initcall(psci_idle_init);
Commit	Line	Data
81d549e0 LP	1	// SPDX-License-Identifier: GPL-2.0-only
	2	/*
	3	* PSCI CPU idle driver.
	4	*
	5	* Copyright (C) 2019 ARM Ltd.
	6	* Author: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
	7	*/
	8
	9	#define pr_fmt(fmt) "CPUidle PSCI: " fmt
	10
9c6ceecb	11	#include <linux/cpuhotplug.h>
fc7a3d9e	12	#include <linux/cpu_cooling.h>
81d549e0 LP	13	#include <linux/cpuidle.h>
	14	#include <linux/cpumask.h>
	15	#include <linux/cpu_pm.h>
	16	#include <linux/kernel.h>
	17	#include <linux/module.h>
	18	#include <linux/of.h>
	19	#include <linux/of_device.h>
166bf835	20	#include <linux/platform_device.h>
81d549e0	21	#include <linux/psci.h>
670c90de	22	#include <linux/pm_domain.h>
ce85aef5	23	#include <linux/pm_runtime.h>
81d549e0	24	#include <linux/slab.h>
166bf835	25	#include <linux/string.h>
81d549e0 LP	26
	27	#include <asm/cpuidle.h>
	28
8554951a	29	#include "cpuidle-psci.h"
81d549e0 LP	30	#include "dt_idle_states.h"
81d549e0 LP	31
8554951a UH	32	struct psci_cpuidle_data {
	33	u32 *psci_states;
	34	struct device *dev;
	35	};
	36
	37	static DEFINE_PER_CPU_READ_MOSTLY(struct psci_cpuidle_data, psci_cpuidle_data);
a0cf3194	38	static DEFINE_PER_CPU(u32, domain_state);
166bf835	39	static bool psci_cpuidle_use_cpuhp;
a0cf3194	40
a65a397f	41	void psci_set_domain_state(u32 state)
a0cf3194 UH	42	{
	43	__this_cpu_write(domain_state, state);
	44	}
	45
	46	static inline u32 psci_get_domain_state(void)
	47	{
	48	return __this_cpu_read(domain_state);
	49	}
	50
	51	static inline int psci_enter_state(int idx, u32 state)
	52	{
	53	return CPU_PM_CPU_IDLE_ENTER_PARAM(psci_cpu_suspend_enter, idx, state);
	54	}
	55
670c90de UH	56	static int __psci_enter_domain_idle_state(struct cpuidle_device *dev,
	57	struct cpuidle_driver *drv, int idx,
	58	bool s2idle)
a0cf3194 UH	59	{
	60	struct psci_cpuidle_data *data = this_cpu_ptr(&psci_cpuidle_data);
	61	u32 *states = data->psci_states;
ce85aef5 UH	62	struct device *pd_dev = data->dev;
ce85aef5 UH	63	u32 state;
a0cf3194 UH	64	int ret;
a0cf3194 UH	65
8b7ce5e4 UH	66	ret = cpu_pm_enter();
	67	if (ret)
	68	return -1;
	69
ce85aef5	70	/* Do runtime PM to manage a hierarchical CPU toplogy. */
670c90de UH	71	rcu_irq_enter_irqson();
	72	if (s2idle)
	73	dev_pm_genpd_suspend(pd_dev);
	74	else
	75	pm_runtime_put_sync_suspend(pd_dev);
	76	rcu_irq_exit_irqson();
ce85aef5 UH	77
ce85aef5 UH	78	state = psci_get_domain_state();
a0cf3194 UH	79	if (!state)
	80	state = states[idx];
	81
8b7ce5e4	82	ret = psci_cpu_suspend_enter(state) ? -1 : idx;
a0cf3194	83
670c90de UH	84	rcu_irq_enter_irqson();
	85	if (s2idle)
	86	dev_pm_genpd_resume(pd_dev);
	87	else
	88	pm_runtime_get_sync(pd_dev);
	89	rcu_irq_exit_irqson();
ce85aef5	90
8b7ce5e4 UH	91	cpu_pm_exit();
8b7ce5e4 UH	92
a0cf3194 UH	93	/* Clear the domain state to start fresh when back from idle. */
	94	psci_set_domain_state(0);
	95	return ret;
	96	}
9ffeb6d0	97
670c90de UH	98	static int psci_enter_domain_idle_state(struct cpuidle_device *dev,
	99	struct cpuidle_driver *drv, int idx)
	100	{
	101	return __psci_enter_domain_idle_state(dev, drv, idx, false);
	102	}
	103
	104	static int psci_enter_s2idle_domain_idle_state(struct cpuidle_device *dev,
	105	struct cpuidle_driver *drv,
	106	int idx)
	107	{
	108	return __psci_enter_domain_idle_state(dev, drv, idx, true);
	109	}
	110
9c6ceecb UH	111	static int psci_idle_cpuhp_up(unsigned int cpu)
	112	{
	113	struct device *pd_dev = __this_cpu_read(psci_cpuidle_data.dev);
	114
	115	if (pd_dev)
	116	pm_runtime_get_sync(pd_dev);
	117
	118	return 0;
	119	}
	120
	121	static int psci_idle_cpuhp_down(unsigned int cpu)
	122	{
	123	struct device *pd_dev = __this_cpu_read(psci_cpuidle_data.dev);
	124
	125	if (pd_dev) {
	126	pm_runtime_put_sync(pd_dev);
	127	/* Clear domain state to start fresh at next online. */
	128	psci_set_domain_state(0);
	129	}
	130
	131	return 0;
	132	}
	133
166bf835	134	static void psci_idle_init_cpuhp(void)
9c6ceecb UH	135	{
	136	int err;
	137
	138	if (!psci_cpuidle_use_cpuhp)
	139	return;
	140
	141	err = cpuhp_setup_state_nocalls(CPUHP_AP_CPU_PM_STARTING,
	142	"cpuidle/psci:online",
	143	psci_idle_cpuhp_up,
	144	psci_idle_cpuhp_down);
	145	if (err)
	146	pr_warn("Failed %d while setup cpuhp state\n", err);
	147	}
	148
81d549e0 LP	149	static int psci_enter_idle_state(struct cpuidle_device *dev,
	150	struct cpuidle_driver *drv, int idx)
	151	{
8554951a	152	u32 *state = __this_cpu_read(psci_cpuidle_data.psci_states);
9ffeb6d0	153
a0cf3194	154	return psci_enter_state(idx, state[idx]);
81d549e0 LP	155	}
81d549e0 LP	156
166bf835	157	static const struct of_device_id psci_idle_state_match[] = {
81d549e0 LP	158	{ .compatible = "arm,idle-state",
	159	.data = psci_enter_idle_state },
	160	{ },
	161	};
	162
166bf835	163	int psci_dt_parse_state_node(struct device_node np, u32 state)
9ffeb6d0 LP	164	{
	165	int err = of_property_read_u32(np, "arm,psci-suspend-param", state);
	166
	167	if (err) {
	168	pr_warn("%pOF missing arm,psci-suspend-param property\n", np);
	169	return err;
	170	}
	171
	172	if (!psci_power_state_is_valid(*state)) {
	173	pr_warn("Invalid PSCI power state %#x\n", *state);
	174	return -EINVAL;
	175	}
	176
	177	return 0;
	178	}
	179
166bf835 UH	180	static int psci_dt_cpu_init_topology(struct cpuidle_driver *drv,
	181	struct psci_cpuidle_data *data,
	182	unsigned int state_count, int cpu)
7fbee48e UH	183	{
	184	/* Currently limit the hierarchical topology to be used in OSI mode. */
	185	if (!psci_has_osi_support())
	186	return 0;
	187
	188	data->dev = psci_dt_attach_cpu(cpu);
	189	if (IS_ERR_OR_NULL(data->dev))
	190	return PTR_ERR_OR_ZERO(data->dev);
	191
	192	/*
	193	* Using the deepest state for the CPU to trigger a potential selection
	194	* of a shared state for the domain, assumes the domain states are all
	195	* deeper states.
	196	*/
	197	drv->states[state_count - 1].enter = psci_enter_domain_idle_state;
670c90de	198	drv->states[state_count - 1].enter_s2idle = psci_enter_s2idle_domain_idle_state;
7fbee48e UH	199	psci_cpuidle_use_cpuhp = true;
	200
	201	return 0;
	202	}
	203
166bf835 UH	204	static int psci_dt_cpu_init_idle(struct device dev, struct cpuidle_driver drv,
	205	struct device_node *cpu_node,
	206	unsigned int state_count, int cpu)
9ffeb6d0	207	{
1595e4b0	208	int i, ret = 0;
9ffeb6d0 LP	209	u32 *psci_states;
9ffeb6d0 LP	210	struct device_node *state_node;
8554951a	211	struct psci_cpuidle_data *data = per_cpu_ptr(&psci_cpuidle_data, cpu);
9ffeb6d0	212
1595e4b0	213	state_count++; /* Add WFI state too */
166bf835 UH	214	psci_states = devm_kcalloc(dev, state_count, sizeof(*psci_states),
166bf835 UH	215	GFP_KERNEL);
9ffeb6d0 LP	216	if (!psci_states)
	217	return -ENOMEM;
	218
1595e4b0	219	for (i = 1; i < state_count; i++) {
f08cfbfa	220	state_node = of_get_cpu_state_node(cpu_node, i - 1);
1595e4b0 UH	221	if (!state_node)
	222	break;
	223
9ffeb6d0 LP	224	ret = psci_dt_parse_state_node(state_node, &psci_states[i]);
	225	of_node_put(state_node);
	226
	227	if (ret)
166bf835	228	return ret;
9ffeb6d0 LP	229
	230	pr_debug("psci-power-state %#x index %d\n", psci_states[i], i);
	231	}
	232
166bf835 UH	233	if (i != state_count)
166bf835 UH	234	return -ENODEV;
1595e4b0	235
7fbee48e UH	236	/* Initialize optional data, used for the hierarchical topology. */
	237	ret = psci_dt_cpu_init_topology(drv, data, state_count, cpu);
	238	if (ret < 0)
166bf835	239	return ret;
8554951a UH	240
	241	/* Idle states parsed correctly, store them in the per-cpu struct. */
	242	data->psci_states = psci_states;
9ffeb6d0	243	return 0;
9ffeb6d0 LP	244	}
9ffeb6d0 LP	245
166bf835 UH	246	static int psci_cpu_init_idle(struct device dev, struct cpuidle_driver drv,
166bf835 UH	247	unsigned int cpu, unsigned int state_count)
9ffeb6d0 LP	248	{
	249	struct device_node *cpu_node;
	250	int ret;
	251
	252	/*
	253	* If the PSCI cpu_suspend function hook has not been initialized
	254	* idle states must not be enabled, so bail out
	255	*/
	256	if (!psci_ops.cpu_suspend)
	257	return -EOPNOTSUPP;
	258
	259	cpu_node = of_cpu_device_node_get(cpu);
	260	if (!cpu_node)
	261	return -ENODEV;
	262
166bf835	263	ret = psci_dt_cpu_init_idle(dev, drv, cpu_node, state_count, cpu);
9ffeb6d0 LP	264
	265	of_node_put(cpu_node);
	266
	267	return ret;
	268	}
	269
166bf835 UH	270	static void psci_cpu_deinit_idle(int cpu)
	271	{
	272	struct psci_cpuidle_data *data = per_cpu_ptr(&psci_cpuidle_data, cpu);
	273
	274	psci_dt_detach_cpu(data->dev);
	275	psci_cpuidle_use_cpuhp = false;
	276	}
	277
	278	static int psci_idle_init_cpu(struct device *dev, int cpu)
81d549e0 LP	279	{
	280	struct cpuidle_driver *drv;
	281	struct device_node *cpu_node;
	282	const char *enable_method;
	283	int ret = 0;
	284
	285	cpu_node = of_cpu_device_node_get(cpu);
	286	if (!cpu_node)
	287	return -ENODEV;
	288
	289	/*
	290	* Check whether the enable-method for the cpu is PSCI, fail
	291	* if it is not.
	292	*/
	293	enable_method = of_get_property(cpu_node, "enable-method", NULL);
	294	if (!enable_method \|\| (strcmp(enable_method, "psci")))
	295	ret = -ENODEV;
	296
	297	of_node_put(cpu_node);
	298	if (ret)
	299	return ret;
	300
166bf835	301	drv = devm_kzalloc(dev, sizeof(*drv), GFP_KERNEL);
81d549e0 LP	302	if (!drv)
	303	return -ENOMEM;
	304
166bf835 UH	305	drv->name = "psci_idle";
166bf835 UH	306	drv->owner = THIS_MODULE;
81d549e0 LP	307	drv->cpumask = (struct cpumask *)cpumask_of(cpu);
	308
	309	/*
166bf835 UH	310	* PSCI idle states relies on architectural WFI to be represented as
	311	* state index 0.
	312	*/
	313	drv->states[0].enter = psci_enter_idle_state;
	314	drv->states[0].exit_latency = 1;
	315	drv->states[0].target_residency = 1;
	316	drv->states[0].power_usage = UINT_MAX;
	317	strcpy(drv->states[0].name, "WFI");
	318	strcpy(drv->states[0].desc, "ARM WFI");
	319
	320	/*
81d549e0 LP	321	* If no DT idle states are detected (ret == 0) let the driver
	322	* initialization fail accordingly since there is no reason to
	323	* initialize the idle driver if only wfi is supported, the
	324	* default archictectural back-end already executes wfi
	325	* on idle entry.
	326	*/
	327	ret = dt_init_idle_driver(drv, psci_idle_state_match, 1);
166bf835 UH	328	if (ret <= 0)
166bf835 UH	329	return ret ? : -ENODEV;
81d549e0 LP	330
	331	/*
	332	* Initialize PSCI idle states.
	333	*/
166bf835	334	ret = psci_cpu_init_idle(dev, drv, cpu, ret);
81d549e0 LP	335	if (ret) {
81d549e0 LP	336	pr_err("CPU %d failed to PSCI idle\n", cpu);
166bf835	337	return ret;
81d549e0 LP	338	}
	339
	340	ret = cpuidle_register(drv, NULL);
	341	if (ret)
166bf835	342	goto deinit;
81d549e0	343
fc7a3d9e DL	344	cpuidle_cooling_register(drv);
fc7a3d9e DL	345
81d549e0	346	return 0;
166bf835 UH	347	deinit:
166bf835 UH	348	psci_cpu_deinit_idle(cpu);
81d549e0 LP	349	return ret;
	350	}
	351
	352	/*
166bf835	353	* psci_idle_probe - Initializes PSCI cpuidle driver
81d549e0 LP	354	*
	355	* Initializes PSCI cpuidle driver for all CPUs, if any CPU fails
	356	* to register cpuidle driver then rollback to cancel all CPUs
	357	* registration.
	358	*/
166bf835	359	static int psci_cpuidle_probe(struct platform_device *pdev)
81d549e0 LP	360	{
	361	int cpu, ret;
	362	struct cpuidle_driver *drv;
	363	struct cpuidle_device *dev;
	364
	365	for_each_possible_cpu(cpu) {
166bf835	366	ret = psci_idle_init_cpu(&pdev->dev, cpu);
81d549e0 LP	367	if (ret)
	368	goto out_fail;
	369	}
	370
9c6ceecb	371	psci_idle_init_cpuhp();
81d549e0 LP	372	return 0;
	373
	374	out_fail:
	375	while (--cpu >= 0) {
	376	dev = per_cpu(cpuidle_devices, cpu);
	377	drv = cpuidle_get_cpu_driver(dev);
	378	cpuidle_unregister(drv);
166bf835	379	psci_cpu_deinit_idle(cpu);
81d549e0 LP	380	}
	381
	382	return ret;
	383	}
166bf835 UH	384
	385	static struct platform_driver psci_cpuidle_driver = {
	386	.probe = psci_cpuidle_probe,
	387	.driver = {
	388	.name = "psci-cpuidle",
	389	},
	390	};
	391
	392	static int __init psci_idle_init(void)
	393	{
	394	struct platform_device *pdev;
	395	int ret;
	396
	397	ret = platform_driver_register(&psci_cpuidle_driver);
	398	if (ret)
	399	return ret;
	400
	401	pdev = platform_device_register_simple("psci-cpuidle", -1, NULL, 0);
	402	if (IS_ERR(pdev)) {
	403	platform_driver_unregister(&psci_cpuidle_driver);
	404	return PTR_ERR(pdev);
	405	}
	406
	407	return 0;
	408	}
81d549e0	409	device_initcall(psci_idle_init);