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
  28 static 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(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
  52 static 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
  61 static int db8500_cpufreq_cooling_suspend(struct platform_device *pdev,
  62                 pm_message_t state)
  63 {
  64         return -ENOSYS;
  65 }
  66
  67 static int db8500_cpufreq_cooling_resume(struct platform_device *pdev)
  68 {
  69         return -ENOSYS;
  70 }
  71
  72 #ifdef CONFIG_OF
  73 static const struct of_device_id db8500_cpufreq_cooling_match[] = {
  74         { .compatible = "stericsson,db8500-cpufreq-cooling" },
  75         {},
  76 };
  77 #endif
  78
  79 static 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
  91 static int __init db8500_cpufreq_cooling_init(void)
  92 {
  93         return platform_driver_register(&db8500_cpufreq_cooling_driver);
  94 }
  95
  96 static 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 */
 102 late_initcall(db8500_cpufreq_cooling_init);
 103 module_exit(db8500_cpufreq_cooling_exit);
 104
 105 MODULE_AUTHOR("Hongbo Zhang <hongbo.zhang@stericsson.com>");
 106 MODULE_DESCRIPTION("DB8500 cpufreq cooling driver");
 107 MODULE_LICENSE("GPL");