[linux-2.6-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 <linux/syscore_ops.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. */
	ct_irq_enter_irqson();
	if (s2idle)
		dev_pm_genpd_suspend(pd_dev);
	else
		pm_runtime_put_sync_suspend(pd_dev);
	ct_irq_exit_irqson();

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

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

	ct_irq_enter_irqson();
	if (s2idle)
		dev_pm_genpd_resume(pd_dev);
	else
		pm_runtime_get_sync(pd_dev);
	ct_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_syscore_switch(bool suspend)
{
	bool cleared = false;
	struct device *dev;
	int cpu;

	for_each_possible_cpu(cpu) {
		dev = per_cpu_ptr(&psci_cpuidle_data, cpu)->dev;

		if (dev && suspend) {
			dev_pm_genpd_suspend(dev);
		} else if (dev) {
			dev_pm_genpd_resume(dev);

			/* Account for userspace having offlined a CPU. */
			if (pm_runtime_status_suspended(dev))
				pm_runtime_set_active(dev);

			/* Clear domain state to re-start fresh. */
			if (!cleared) {
				psci_set_domain_state(0);
				cleared = true;
			}
		}
	}
}

static int psci_idle_syscore_suspend(void)
{
	psci_idle_syscore_switch(true);
	return 0;
}

static void psci_idle_syscore_resume(void)
{
	psci_idle_syscore_switch(false);
}

static struct syscore_ops psci_idle_syscore_ops = {
	.suspend = psci_idle_syscore_suspend,
	.resume = psci_idle_syscore_resume,
};

static void psci_idle_init_cpuhp(void)
{
	int err;

	if (!psci_cpuidle_use_cpuhp)
		return;

	register_syscore_ops(&psci_idle_syscore_ops);

	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>
171b66e2	26	#include <linux/syscore_ops.h>
81d549e0 LP	27
	28	#include <asm/cpuidle.h>
	29
8554951a	30	#include "cpuidle-psci.h"
81d549e0 LP	31	#include "dt_idle_states.h"
81d549e0 LP	32
8554951a UH	33	struct psci_cpuidle_data {
	34	u32 *psci_states;
	35	struct device *dev;
	36	};
	37
	38	static DEFINE_PER_CPU_READ_MOSTLY(struct psci_cpuidle_data, psci_cpuidle_data);
a0cf3194	39	static DEFINE_PER_CPU(u32, domain_state);
166bf835	40	static bool psci_cpuidle_use_cpuhp;
a0cf3194	41
a65a397f	42	void psci_set_domain_state(u32 state)
a0cf3194 UH	43	{
	44	__this_cpu_write(domain_state, state);
	45	}
	46
	47	static inline u32 psci_get_domain_state(void)
	48	{
	49	return __this_cpu_read(domain_state);
	50	}
	51
	52	static inline int psci_enter_state(int idx, u32 state)
	53	{
	54	return CPU_PM_CPU_IDLE_ENTER_PARAM(psci_cpu_suspend_enter, idx, state);
	55	}
	56
670c90de UH	57	static int __psci_enter_domain_idle_state(struct cpuidle_device *dev,
	58	struct cpuidle_driver *drv, int idx,
	59	bool s2idle)
a0cf3194 UH	60	{
	61	struct psci_cpuidle_data *data = this_cpu_ptr(&psci_cpuidle_data);
	62	u32 *states = data->psci_states;
ce85aef5 UH	63	struct device *pd_dev = data->dev;
ce85aef5 UH	64	u32 state;
a0cf3194 UH	65	int ret;
a0cf3194 UH	66
8b7ce5e4 UH	67	ret = cpu_pm_enter();
	68	if (ret)
	69	return -1;
	70
ce85aef5	71	/* Do runtime PM to manage a hierarchical CPU toplogy. */
6f0e6c15	72	ct_irq_enter_irqson();
670c90de UH	73	if (s2idle)
	74	dev_pm_genpd_suspend(pd_dev);
	75	else
	76	pm_runtime_put_sync_suspend(pd_dev);
6f0e6c15	77	ct_irq_exit_irqson();
ce85aef5 UH	78
ce85aef5 UH	79	state = psci_get_domain_state();
a0cf3194 UH	80	if (!state)
	81	state = states[idx];
	82
8b7ce5e4	83	ret = psci_cpu_suspend_enter(state) ? -1 : idx;
a0cf3194	84
6f0e6c15	85	ct_irq_enter_irqson();
670c90de UH	86	if (s2idle)
	87	dev_pm_genpd_resume(pd_dev);
	88	else
	89	pm_runtime_get_sync(pd_dev);
6f0e6c15	90	ct_irq_exit_irqson();
ce85aef5	91
8b7ce5e4 UH	92	cpu_pm_exit();
8b7ce5e4 UH	93
a0cf3194 UH	94	/* Clear the domain state to start fresh when back from idle. */
	95	psci_set_domain_state(0);
	96	return ret;
	97	}
9ffeb6d0	98
670c90de UH	99	static int psci_enter_domain_idle_state(struct cpuidle_device *dev,
	100	struct cpuidle_driver *drv, int idx)
	101	{
	102	return __psci_enter_domain_idle_state(dev, drv, idx, false);
	103	}
	104
	105	static int psci_enter_s2idle_domain_idle_state(struct cpuidle_device *dev,
	106	struct cpuidle_driver *drv,
	107	int idx)
	108	{
	109	return __psci_enter_domain_idle_state(dev, drv, idx, true);
	110	}
	111
9c6ceecb UH	112	static int psci_idle_cpuhp_up(unsigned int cpu)
	113	{
	114	struct device *pd_dev = __this_cpu_read(psci_cpuidle_data.dev);
	115
	116	if (pd_dev)
	117	pm_runtime_get_sync(pd_dev);
	118
	119	return 0;
	120	}
	121
	122	static int psci_idle_cpuhp_down(unsigned int cpu)
	123	{
	124	struct device *pd_dev = __this_cpu_read(psci_cpuidle_data.dev);
	125
	126	if (pd_dev) {
	127	pm_runtime_put_sync(pd_dev);
	128	/* Clear domain state to start fresh at next online. */
	129	psci_set_domain_state(0);
	130	}
	131
	132	return 0;
	133	}
	134
171b66e2 UH	135	static void psci_idle_syscore_switch(bool suspend)
	136	{
	137	bool cleared = false;
	138	struct device *dev;
	139	int cpu;
	140
	141	for_each_possible_cpu(cpu) {
	142	dev = per_cpu_ptr(&psci_cpuidle_data, cpu)->dev;
	143
	144	if (dev && suspend) {
	145	dev_pm_genpd_suspend(dev);
	146	} else if (dev) {
	147	dev_pm_genpd_resume(dev);
	148
	149	/* Account for userspace having offlined a CPU. */
	150	if (pm_runtime_status_suspended(dev))
	151	pm_runtime_set_active(dev);
	152
	153	/* Clear domain state to re-start fresh. */
	154	if (!cleared) {
	155	psci_set_domain_state(0);
	156	cleared = true;
	157	}
	158	}
	159	}
	160	}
	161
	162	static int psci_idle_syscore_suspend(void)
	163	{
	164	psci_idle_syscore_switch(true);
	165	return 0;
	166	}
	167
	168	static void psci_idle_syscore_resume(void)
	169	{
	170	psci_idle_syscore_switch(false);
	171	}
	172
	173	static struct syscore_ops psci_idle_syscore_ops = {
	174	.suspend = psci_idle_syscore_suspend,
	175	.resume = psci_idle_syscore_resume,
	176	};
	177
166bf835	178	static void psci_idle_init_cpuhp(void)
9c6ceecb UH	179	{
	180	int err;
	181
	182	if (!psci_cpuidle_use_cpuhp)
	183	return;
	184
171b66e2 UH	185	register_syscore_ops(&psci_idle_syscore_ops);
171b66e2 UH	186
9c6ceecb UH	187	err = cpuhp_setup_state_nocalls(CPUHP_AP_CPU_PM_STARTING,
	188	"cpuidle/psci:online",
	189	psci_idle_cpuhp_up,
	190	psci_idle_cpuhp_down);
	191	if (err)
	192	pr_warn("Failed %d while setup cpuhp state\n", err);
	193	}
	194
81d549e0 LP	195	static int psci_enter_idle_state(struct cpuidle_device *dev,
	196	struct cpuidle_driver *drv, int idx)
	197	{
8554951a	198	u32 *state = __this_cpu_read(psci_cpuidle_data.psci_states);
9ffeb6d0	199
a0cf3194	200	return psci_enter_state(idx, state[idx]);
81d549e0 LP	201	}
81d549e0 LP	202
166bf835	203	static const struct of_device_id psci_idle_state_match[] = {
81d549e0 LP	204	{ .compatible = "arm,idle-state",
	205	.data = psci_enter_idle_state },
	206	{ },
	207	};
	208
166bf835	209	int psci_dt_parse_state_node(struct device_node np, u32 state)
9ffeb6d0 LP	210	{
	211	int err = of_property_read_u32(np, "arm,psci-suspend-param", state);
	212
	213	if (err) {
	214	pr_warn("%pOF missing arm,psci-suspend-param property\n", np);
	215	return err;
	216	}
	217
	218	if (!psci_power_state_is_valid(*state)) {
	219	pr_warn("Invalid PSCI power state %#x\n", *state);
	220	return -EINVAL;
	221	}
	222
	223	return 0;
	224	}
	225
166bf835 UH	226	static int psci_dt_cpu_init_topology(struct cpuidle_driver *drv,
	227	struct psci_cpuidle_data *data,
	228	unsigned int state_count, int cpu)
7fbee48e UH	229	{
	230	/* Currently limit the hierarchical topology to be used in OSI mode. */
	231	if (!psci_has_osi_support())
	232	return 0;
	233
	234	data->dev = psci_dt_attach_cpu(cpu);
	235	if (IS_ERR_OR_NULL(data->dev))
	236	return PTR_ERR_OR_ZERO(data->dev);
	237
	238	/*
	239	* Using the deepest state for the CPU to trigger a potential selection
	240	* of a shared state for the domain, assumes the domain states are all
	241	* deeper states.
	242	*/
	243	drv->states[state_count - 1].enter = psci_enter_domain_idle_state;
670c90de	244	drv->states[state_count - 1].enter_s2idle = psci_enter_s2idle_domain_idle_state;
7fbee48e UH	245	psci_cpuidle_use_cpuhp = true;
	246
	247	return 0;
	248	}
	249
166bf835 UH	250	static int psci_dt_cpu_init_idle(struct device dev, struct cpuidle_driver drv,
	251	struct device_node *cpu_node,
	252	unsigned int state_count, int cpu)
9ffeb6d0	253	{
1595e4b0	254	int i, ret = 0;
9ffeb6d0 LP	255	u32 *psci_states;
9ffeb6d0 LP	256	struct device_node *state_node;
8554951a	257	struct psci_cpuidle_data *data = per_cpu_ptr(&psci_cpuidle_data, cpu);
9ffeb6d0	258
1595e4b0	259	state_count++; /* Add WFI state too */
166bf835 UH	260	psci_states = devm_kcalloc(dev, state_count, sizeof(*psci_states),
166bf835 UH	261	GFP_KERNEL);
9ffeb6d0 LP	262	if (!psci_states)
	263	return -ENOMEM;
	264
1595e4b0	265	for (i = 1; i < state_count; i++) {
f08cfbfa	266	state_node = of_get_cpu_state_node(cpu_node, i - 1);
1595e4b0 UH	267	if (!state_node)
	268	break;
	269
9ffeb6d0 LP	270	ret = psci_dt_parse_state_node(state_node, &psci_states[i]);
	271	of_node_put(state_node);
	272
	273	if (ret)
166bf835	274	return ret;
9ffeb6d0 LP	275
	276	pr_debug("psci-power-state %#x index %d\n", psci_states[i], i);
	277	}
	278
166bf835 UH	279	if (i != state_count)
166bf835 UH	280	return -ENODEV;
1595e4b0	281
7fbee48e UH	282	/* Initialize optional data, used for the hierarchical topology. */
	283	ret = psci_dt_cpu_init_topology(drv, data, state_count, cpu);
	284	if (ret < 0)
166bf835	285	return ret;
8554951a UH	286
	287	/* Idle states parsed correctly, store them in the per-cpu struct. */
	288	data->psci_states = psci_states;
9ffeb6d0	289	return 0;
9ffeb6d0 LP	290	}
9ffeb6d0 LP	291
166bf835 UH	292	static int psci_cpu_init_idle(struct device dev, struct cpuidle_driver drv,
166bf835 UH	293	unsigned int cpu, unsigned int state_count)
9ffeb6d0 LP	294	{
	295	struct device_node *cpu_node;
	296	int ret;
	297
	298	/*
	299	* If the PSCI cpu_suspend function hook has not been initialized
	300	* idle states must not be enabled, so bail out
	301	*/
	302	if (!psci_ops.cpu_suspend)
	303	return -EOPNOTSUPP;
	304
	305	cpu_node = of_cpu_device_node_get(cpu);
	306	if (!cpu_node)
	307	return -ENODEV;
	308
166bf835	309	ret = psci_dt_cpu_init_idle(dev, drv, cpu_node, state_count, cpu);
9ffeb6d0 LP	310
	311	of_node_put(cpu_node);
	312
	313	return ret;
	314	}
	315
166bf835 UH	316	static void psci_cpu_deinit_idle(int cpu)
	317	{
	318	struct psci_cpuidle_data *data = per_cpu_ptr(&psci_cpuidle_data, cpu);
	319
	320	psci_dt_detach_cpu(data->dev);
	321	psci_cpuidle_use_cpuhp = false;
	322	}
	323
	324	static int psci_idle_init_cpu(struct device *dev, int cpu)
81d549e0 LP	325	{
	326	struct cpuidle_driver *drv;
	327	struct device_node *cpu_node;
	328	const char *enable_method;
	329	int ret = 0;
	330
	331	cpu_node = of_cpu_device_node_get(cpu);
	332	if (!cpu_node)
	333	return -ENODEV;
	334
	335	/*
	336	* Check whether the enable-method for the cpu is PSCI, fail
	337	* if it is not.
	338	*/
	339	enable_method = of_get_property(cpu_node, "enable-method", NULL);
	340	if (!enable_method \|\| (strcmp(enable_method, "psci")))
	341	ret = -ENODEV;
	342
	343	of_node_put(cpu_node);
	344	if (ret)
	345	return ret;
	346
166bf835	347	drv = devm_kzalloc(dev, sizeof(*drv), GFP_KERNEL);
81d549e0 LP	348	if (!drv)
	349	return -ENOMEM;
	350
166bf835 UH	351	drv->name = "psci_idle";
166bf835 UH	352	drv->owner = THIS_MODULE;
81d549e0 LP	353	drv->cpumask = (struct cpumask *)cpumask_of(cpu);
	354
	355	/*
166bf835 UH	356	* PSCI idle states relies on architectural WFI to be represented as
	357	* state index 0.
	358	*/
	359	drv->states[0].enter = psci_enter_idle_state;
	360	drv->states[0].exit_latency = 1;
	361	drv->states[0].target_residency = 1;
	362	drv->states[0].power_usage = UINT_MAX;
	363	strcpy(drv->states[0].name, "WFI");
	364	strcpy(drv->states[0].desc, "ARM WFI");
	365
	366	/*
81d549e0 LP	367	* If no DT idle states are detected (ret == 0) let the driver
	368	* initialization fail accordingly since there is no reason to
	369	* initialize the idle driver if only wfi is supported, the
	370	* default archictectural back-end already executes wfi
	371	* on idle entry.
	372	*/
	373	ret = dt_init_idle_driver(drv, psci_idle_state_match, 1);
166bf835 UH	374	if (ret <= 0)
166bf835 UH	375	return ret ? : -ENODEV;
81d549e0 LP	376
	377	/*
	378	* Initialize PSCI idle states.
	379	*/
166bf835	380	ret = psci_cpu_init_idle(dev, drv, cpu, ret);
81d549e0 LP	381	if (ret) {
81d549e0 LP	382	pr_err("CPU %d failed to PSCI idle\n", cpu);
166bf835	383	return ret;
81d549e0 LP	384	}
	385
	386	ret = cpuidle_register(drv, NULL);
	387	if (ret)
166bf835	388	goto deinit;
81d549e0	389
fc7a3d9e DL	390	cpuidle_cooling_register(drv);
fc7a3d9e DL	391
81d549e0	392	return 0;
166bf835 UH	393	deinit:
166bf835 UH	394	psci_cpu_deinit_idle(cpu);
81d549e0 LP	395	return ret;
	396	}
	397
	398	/*
166bf835	399	* psci_idle_probe - Initializes PSCI cpuidle driver
81d549e0 LP	400	*
	401	* Initializes PSCI cpuidle driver for all CPUs, if any CPU fails
	402	* to register cpuidle driver then rollback to cancel all CPUs
	403	* registration.
	404	*/
166bf835	405	static int psci_cpuidle_probe(struct platform_device *pdev)
81d549e0 LP	406	{
	407	int cpu, ret;
	408	struct cpuidle_driver *drv;
	409	struct cpuidle_device *dev;
	410
	411	for_each_possible_cpu(cpu) {
166bf835	412	ret = psci_idle_init_cpu(&pdev->dev, cpu);
81d549e0 LP	413	if (ret)
	414	goto out_fail;
	415	}
	416
9c6ceecb	417	psci_idle_init_cpuhp();
81d549e0 LP	418	return 0;
	419
	420	out_fail:
	421	while (--cpu >= 0) {
	422	dev = per_cpu(cpuidle_devices, cpu);
	423	drv = cpuidle_get_cpu_driver(dev);
	424	cpuidle_unregister(drv);
166bf835	425	psci_cpu_deinit_idle(cpu);
81d549e0 LP	426	}
	427
	428	return ret;
	429	}
166bf835 UH	430
	431	static struct platform_driver psci_cpuidle_driver = {
	432	.probe = psci_cpuidle_probe,
	433	.driver = {
	434	.name = "psci-cpuidle",
	435	},
	436	};
	437
	438	static int __init psci_idle_init(void)
	439	{
	440	struct platform_device *pdev;
	441	int ret;
	442
	443	ret = platform_driver_register(&psci_cpuidle_driver);
	444	if (ret)
	445	return ret;
	446
	447	pdev = platform_device_register_simple("psci-cpuidle", -1, NULL, 0);
	448	if (IS_ERR(pdev)) {
	449	platform_driver_unregister(&psci_cpuidle_driver);
	450	return PTR_ERR(pdev);
	451	}
	452
	453	return 0;
	454	}
81d549e0	455	device_initcall(psci_idle_init);