1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (c) 2011-2014, The Linux Foundation. All rights reserved.
4 * Copyright (c) 2014,2015, Linaro Ltd.
5 *
6 * SAW power controller driver
7 */
8
9#include <linux/kernel.h>
10#include <linux/init.h>
11#include <linux/io.h>
12#include <linux/slab.h>
13#include <linux/of.h>
14#include <linux/of_platform.h>
15#include <linux/err.h>
16#include <linux/platform_device.h>
17#include <linux/cpuidle.h>
18#include <linux/cpu_pm.h>
19#include <linux/firmware/qcom/qcom_scm.h>
20#include <soc/qcom/spm.h>
21
22#include <asm/proc-fns.h>
23#include <asm/suspend.h>
24
25#include "dt_idle_states.h"
26
27struct cpuidle_qcom_spm_data {
28	struct cpuidle_driver cpuidle_driver;
29	struct spm_driver_data *spm;
30};
31
32static int qcom_pm_collapse(unsigned long int unused)
33{
34	qcom_scm_cpu_power_down(QCOM_SCM_CPU_PWR_DOWN_L2_ON);
35
36	/*
37	 * Returns here only if there was a pending interrupt and we did not
38	 * power down as a result.
39	 */
40	return -1;
41}
42
43static int qcom_cpu_spc(struct spm_driver_data *drv)
44{
45	int ret;
46
47	spm_set_low_power_mode(drv, PM_SLEEP_MODE_SPC);
48	ret = cpu_suspend(0, qcom_pm_collapse);
49	/*
50	 * ARM common code executes WFI without calling into our driver and
51	 * if the SPM mode is not reset, then we may accidently power down the
52	 * cpu when we intended only to gate the cpu clock.
53	 * Ensure the state is set to standby before returning.
54	 */
55	spm_set_low_power_mode(drv, PM_SLEEP_MODE_STBY);
56
57	return ret;
58}
59
60static __cpuidle int spm_enter_idle_state(struct cpuidle_device *dev,
61					  struct cpuidle_driver *drv, int idx)
62{
63	struct cpuidle_qcom_spm_data *data = container_of(drv, struct cpuidle_qcom_spm_data,
64							  cpuidle_driver);
65
66	return CPU_PM_CPU_IDLE_ENTER_PARAM(qcom_cpu_spc, idx, data->spm);
67}
68
69static struct cpuidle_driver qcom_spm_idle_driver = {
70	.name = "qcom_spm",
71	.owner = THIS_MODULE,
72	.states[0] = {
73		.enter			= spm_enter_idle_state,
74		.exit_latency		= 1,
75		.target_residency	= 1,
76		.power_usage		= UINT_MAX,
77		.name			= "WFI",
78		.desc			= "ARM WFI",
79	}
80};
81
82static const struct of_device_id qcom_idle_state_match[] = {
83	{ .compatible = "qcom,idle-state-spc", .data = spm_enter_idle_state },
84	{ },
85};
86
87static int spm_cpuidle_register(struct device *cpuidle_dev, int cpu)
88{
89	struct platform_device *pdev = NULL;
90	struct device_node *cpu_node, *saw_node;
91	struct cpuidle_qcom_spm_data *data = NULL;
92	int ret;
93
94	cpu_node = of_cpu_device_node_get(cpu);
95	if (!cpu_node)
96		return -ENODEV;
97
98	saw_node = of_parse_phandle(cpu_node, "qcom,saw", 0);
99	if (!saw_node)
100		return -ENODEV;
101
102	pdev = of_find_device_by_node(saw_node);
103	of_node_put(saw_node);
104	of_node_put(cpu_node);
105	if (!pdev)
106		return -ENODEV;
107
108	data = devm_kzalloc(cpuidle_dev, sizeof(*data), GFP_KERNEL);
109	if (!data)
110		return -ENOMEM;
111
112	data->spm = dev_get_drvdata(&pdev->dev);
113	if (!data->spm)
114		return -EINVAL;
115
116	data->cpuidle_driver = qcom_spm_idle_driver;
117	data->cpuidle_driver.cpumask = (struct cpumask *)cpumask_of(cpu);
118
119	ret = dt_init_idle_driver(&data->cpuidle_driver,
120				  qcom_idle_state_match, 1);
121	if (ret <= 0)
122		return ret ? : -ENODEV;
123
124	return cpuidle_register(&data->cpuidle_driver, NULL);
125}
126
127static int spm_cpuidle_drv_probe(struct platform_device *pdev)
128{
129	int cpu, ret;
130
131	if (!qcom_scm_is_available())
132		return -EPROBE_DEFER;
133
134	ret = qcom_scm_set_warm_boot_addr(cpu_resume_arm);
135	if (ret)
136		return dev_err_probe(&pdev->dev, ret, "set warm boot addr failed");
137
138	for_each_possible_cpu(cpu) {
139		ret = spm_cpuidle_register(&pdev->dev, cpu);
140		if (ret && ret != -ENODEV) {
141			dev_err(&pdev->dev,
142				"Cannot register for CPU%d: %d\n", cpu, ret);
143		}
144	}
145
146	return 0;
147}
148
149static struct platform_driver spm_cpuidle_driver = {
150	.probe = spm_cpuidle_drv_probe,
151	.driver = {
152		.name = "qcom-spm-cpuidle",
153		.suppress_bind_attrs = true,
154	},
155};
156
157static bool __init qcom_spm_find_any_cpu(void)
158{
159	struct device_node *cpu_node, *saw_node;
160
161	for_each_of_cpu_node(cpu_node) {
162		saw_node = of_parse_phandle(cpu_node, "qcom,saw", 0);
163		if (of_device_is_available(saw_node)) {
164			of_node_put(saw_node);
165			of_node_put(cpu_node);
166			return true;
167		}
168		of_node_put(saw_node);
169	}
170	return false;
171}
172
173static int __init qcom_spm_cpuidle_init(void)
174{
175	struct platform_device *pdev;
176	int ret;
177
178	ret = platform_driver_register(&spm_cpuidle_driver);
179	if (ret)
180		return ret;
181
182	/* Make sure there is actually any CPU managed by the SPM */
183	if (!qcom_spm_find_any_cpu())
184		return 0;
185
186	pdev = platform_device_register_simple("qcom-spm-cpuidle",
187					       -1, NULL, 0);
188	if (IS_ERR(pdev)) {
189		platform_driver_unregister(&spm_cpuidle_driver);
190		return PTR_ERR(pdev);
191	}
192
193	return 0;
194}
195device_initcall(qcom_spm_cpuidle_init);
196