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/platform_device.h>
  25 #include <linux/slab.h>
  26
  27 static int db8500_cpufreq_cooling_probe(struct platform_device *pdev)
  28 {
  29         struct thermal_cooling_device *cdev;
  30         struct cpumask mask_val;
  31
  32         /* make sure cpufreq driver has been initialized */
  33         if (!cpufreq_frequency_get_table(0))
  34                 return -EPROBE_DEFER;
  35
  36         cpumask_set_cpu(0, &mask_val);
  37         cdev = cpufreq_cooling_register(&mask_val);
  38
  39         if (IS_ERR_OR_NULL(cdev)) {
  40                 dev_err(&pdev->dev, "Failed to register cooling device\n");
  41                 return PTR_ERR(cdev);
  42         }
  43
  44         platform_set_drvdata(pdev, cdev);
  45
  46         dev_info(&pdev->dev, "Cooling device registered: %s\n", cdev->type);
  47
  48         return 0;
  49 }
  50
  51 static int db8500_cpufreq_cooling_remove(struct platform_device *pdev)
  52 {
  53         struct thermal_cooling_device *cdev = platform_get_drvdata(pdev);
  54
  55         cpufreq_cooling_unregister(cdev);
  56
  57         return 0;
  58 }
  59
  60 static int db8500_cpufreq_cooling_suspend(struct platform_device *pdev,
  61                 pm_message_t state)
  62 {
  63         return -ENOSYS;
  64 }
  65
  66 static int db8500_cpufreq_cooling_resume(struct platform_device *pdev)
  67 {
  68         return -ENOSYS;
  69 }
  70
  71 #ifdef CONFIG_OF
  72 static const struct of_device_id db8500_cpufreq_cooling_match[] = {
  73         { .compatible = "stericsson,db8500-cpufreq-cooling" },
  74         {},
  75 };
  76 #else
  77 #define db8500_cpufreq_cooling_match NULL
  78 #endif
  79
  80 static struct platform_driver db8500_cpufreq_cooling_driver = {
  81         .driver = {
  82                 .owner = THIS_MODULE,
  83                 .name = "db8500-cpufreq-cooling",
  84                 .of_match_table = db8500_cpufreq_cooling_match,
  85         },
  86         .probe = db8500_cpufreq_cooling_probe,
  87         .suspend = db8500_cpufreq_cooling_suspend,
  88         .resume = db8500_cpufreq_cooling_resume,
  89         .remove = db8500_cpufreq_cooling_remove,
  90 };
  91
  92 static int __init db8500_cpufreq_cooling_init(void)
  93 {
  94         return platform_driver_register(&db8500_cpufreq_cooling_driver);
  95 }
  96
  97 static void __exit db8500_cpufreq_cooling_exit(void)
  98 {
  99         platform_driver_unregister(&db8500_cpufreq_cooling_driver);
 100 }
 101
 102 /* Should be later than db8500_cpufreq_register */
 103 late_initcall(db8500_cpufreq_cooling_init);
 104 module_exit(db8500_cpufreq_cooling_exit);
 105
 106 MODULE_AUTHOR("Hongbo Zhang <hongbo.zhang@stericsson.com>");
 107 MODULE_DESCRIPTION("DB8500 cpufreq cooling driver");
 108 MODULE_LICENSE("GPL");