mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-11-18 17:54:13 +08:00
70d23b29e4
This patch changes the driver to avoid the usage of IS_ERR_OR_NULL() macro. This macro can lead to dangerous results, like returning success (0) during a failure scenario (NULL pointer handling). The case present in this driver can be translated to a simple check for IS_ERR(), as the cpufreq_cooling_register() returns either a valid pointer or an ERR_PTR(). Cc: Zhang Rui <rui.zhang@intel.com> Cc: Russell King <rmk@arm.linux.org.uk> Cc: Grant Likely <grant.likely@secretlab.ca> Cc: Rob Herring <rob.herring@calxeda.com> Cc: Hongbo Zhang <hongbo.zhang@stericsson.com> Cc: linux-pm@vger.kernel.org Cc: linux-kernel@vger.kernel.org Cc: devicetree-discuss@lists.ozlabs.org Signed-off-by: Eduardo Valentin <eduardo.valentin@ti.com> Acked-by: Fabio Baltieri <fabio.baltieri@linaro.org> Signed-off-by: Zhang Rui <rui.zhang@intel.com>
108 lines
2.8 KiB
C
108 lines
2.8 KiB
C
/*
|
|
* db8500_cpufreq_cooling.c - DB8500 cpufreq works as cooling device.
|
|
*
|
|
* Copyright (C) 2012 ST-Ericsson
|
|
* Copyright (C) 2012 Linaro Ltd.
|
|
*
|
|
* Author: Hongbo Zhang <hongbo.zhang@linaro.com>
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License as published by
|
|
* the Free Software Foundation; either version 2 of the License, or
|
|
* (at your option) any later version.
|
|
*
|
|
* This program is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
* GNU General Public License for more details.
|
|
*/
|
|
|
|
#include <linux/cpu_cooling.h>
|
|
#include <linux/cpufreq.h>
|
|
#include <linux/err.h>
|
|
#include <linux/module.h>
|
|
#include <linux/of.h>
|
|
#include <linux/platform_device.h>
|
|
#include <linux/slab.h>
|
|
|
|
static int db8500_cpufreq_cooling_probe(struct platform_device *pdev)
|
|
{
|
|
struct thermal_cooling_device *cdev;
|
|
struct cpumask mask_val;
|
|
|
|
/* make sure cpufreq driver has been initialized */
|
|
if (!cpufreq_frequency_get_table(0))
|
|
return -EPROBE_DEFER;
|
|
|
|
cpumask_set_cpu(0, &mask_val);
|
|
cdev = cpufreq_cooling_register(&mask_val);
|
|
|
|
if (IS_ERR(cdev)) {
|
|
dev_err(&pdev->dev, "Failed to register cooling device\n");
|
|
return PTR_ERR(cdev);
|
|
}
|
|
|
|
platform_set_drvdata(pdev, cdev);
|
|
|
|
dev_info(&pdev->dev, "Cooling device registered: %s\n", cdev->type);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int db8500_cpufreq_cooling_remove(struct platform_device *pdev)
|
|
{
|
|
struct thermal_cooling_device *cdev = platform_get_drvdata(pdev);
|
|
|
|
cpufreq_cooling_unregister(cdev);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int db8500_cpufreq_cooling_suspend(struct platform_device *pdev,
|
|
pm_message_t state)
|
|
{
|
|
return -ENOSYS;
|
|
}
|
|
|
|
static int db8500_cpufreq_cooling_resume(struct platform_device *pdev)
|
|
{
|
|
return -ENOSYS;
|
|
}
|
|
|
|
#ifdef CONFIG_OF
|
|
static const struct of_device_id db8500_cpufreq_cooling_match[] = {
|
|
{ .compatible = "stericsson,db8500-cpufreq-cooling" },
|
|
{},
|
|
};
|
|
#endif
|
|
|
|
static struct platform_driver db8500_cpufreq_cooling_driver = {
|
|
.driver = {
|
|
.owner = THIS_MODULE,
|
|
.name = "db8500-cpufreq-cooling",
|
|
.of_match_table = of_match_ptr(db8500_cpufreq_cooling_match),
|
|
},
|
|
.probe = db8500_cpufreq_cooling_probe,
|
|
.suspend = db8500_cpufreq_cooling_suspend,
|
|
.resume = db8500_cpufreq_cooling_resume,
|
|
.remove = db8500_cpufreq_cooling_remove,
|
|
};
|
|
|
|
static int __init db8500_cpufreq_cooling_init(void)
|
|
{
|
|
return platform_driver_register(&db8500_cpufreq_cooling_driver);
|
|
}
|
|
|
|
static void __exit db8500_cpufreq_cooling_exit(void)
|
|
{
|
|
platform_driver_unregister(&db8500_cpufreq_cooling_driver);
|
|
}
|
|
|
|
/* Should be later than db8500_cpufreq_register */
|
|
late_initcall(db8500_cpufreq_cooling_init);
|
|
module_exit(db8500_cpufreq_cooling_exit);
|
|
|
|
MODULE_AUTHOR("Hongbo Zhang <hongbo.zhang@stericsson.com>");
|
|
MODULE_DESCRIPTION("DB8500 cpufreq cooling driver");
|
|
MODULE_LICENSE("GPL");
|