Root/drivers/thermal/db8500_cpufreq_cooling.c

1/*
2 * db8500_cpufreq_cooling.c - DB8500 cpufreq works as cooling device.
3 *
4 * Copyright (C) 2012 ST-Ericsson
5 * Copyright (C) 2012 Linaro Ltd.
6 *
7 * Author: Hongbo Zhang <hongbo.zhang@linaro.com>
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; either version 2 of the License, or
12 * (at your option) any later version.
13 *
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU General Public License for more details.
18 */
19
20#include <linux/cpu_cooling.h>
21#include <linux/cpufreq.h>
22#include <linux/err.h>
23#include <linux/module.h>
24#include <linux/of.h>
25#include <linux/platform_device.h>
26#include <linux/slab.h>
27
28static int db8500_cpufreq_cooling_probe(struct platform_device *pdev)
29{
30    struct thermal_cooling_device *cdev;
31    struct cpumask mask_val;
32
33    /* make sure cpufreq driver has been initialized */
34    if (!cpufreq_frequency_get_table(0))
35        return -EPROBE_DEFER;
36
37    cpumask_set_cpu(0, &mask_val);
38    cdev = cpufreq_cooling_register(&mask_val);
39
40    if (IS_ERR_OR_NULL(cdev)) {
41        dev_err(&pdev->dev, "Failed to register cooling device\n");
42        return PTR_ERR(cdev);
43    }
44
45    platform_set_drvdata(pdev, cdev);
46
47    dev_info(&pdev->dev, "Cooling device registered: %s\n", cdev->type);
48
49    return 0;
50}
51
52static int db8500_cpufreq_cooling_remove(struct platform_device *pdev)
53{
54    struct thermal_cooling_device *cdev = platform_get_drvdata(pdev);
55
56    cpufreq_cooling_unregister(cdev);
57
58    return 0;
59}
60
61static int db8500_cpufreq_cooling_suspend(struct platform_device *pdev,
62        pm_message_t state)
63{
64    return -ENOSYS;
65}
66
67static int db8500_cpufreq_cooling_resume(struct platform_device *pdev)
68{
69    return -ENOSYS;
70}
71
72#ifdef CONFIG_OF
73static const struct of_device_id db8500_cpufreq_cooling_match[] = {
74    { .compatible = "stericsson,db8500-cpufreq-cooling" },
75    {},
76};
77#endif
78
79static struct platform_driver db8500_cpufreq_cooling_driver = {
80    .driver = {
81        .owner = THIS_MODULE,
82        .name = "db8500-cpufreq-cooling",
83        .of_match_table = of_match_ptr(db8500_cpufreq_cooling_match),
84    },
85    .probe = db8500_cpufreq_cooling_probe,
86    .suspend = db8500_cpufreq_cooling_suspend,
87    .resume = db8500_cpufreq_cooling_resume,
88    .remove = db8500_cpufreq_cooling_remove,
89};
90
91static int __init db8500_cpufreq_cooling_init(void)
92{
93    return platform_driver_register(&db8500_cpufreq_cooling_driver);
94}
95
96static void __exit db8500_cpufreq_cooling_exit(void)
97{
98    platform_driver_unregister(&db8500_cpufreq_cooling_driver);
99}
100
101/* Should be later than db8500_cpufreq_register */
102late_initcall(db8500_cpufreq_cooling_init);
103module_exit(db8500_cpufreq_cooling_exit);
104
105MODULE_AUTHOR("Hongbo Zhang <hongbo.zhang@stericsson.com>");
106MODULE_DESCRIPTION("DB8500 cpufreq cooling driver");
107MODULE_LICENSE("GPL");
108

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