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linux-next/drivers/thermal/db8500_cpufreq_cooling.c
Eduardo Valentin 70d23b29e4 thermal: db8500_cpufreq_cooling: remove usage of IS_ERR_OR_NULL()
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>
2013-04-27 09:28:38 +08:00

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");