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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
/*
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* db8500_cpufreq_cooling.c - DB8500 cpufreq works as cooling device.
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*
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* Copyright (C) 2012 ST-Ericsson
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* Copyright (C) 2012 Linaro Ltd.
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*
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* Author: Hongbo Zhang <hongbo.zhang@linaro.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*/
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#include <linux/cpu_cooling.h>
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#include <linux/cpufreq.h>
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#include <linux/err.h>
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#include <linux/module.h>
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#include <linux/of.h>
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#include <linux/platform_device.h>
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#include <linux/slab.h>
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static int db8500_cpufreq_cooling_probe(struct platform_device *pdev)
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{
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struct thermal_cooling_device *cdev;
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struct cpumask mask_val;
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/* make sure cpufreq driver has been initialized */
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if (!cpufreq_frequency_get_table(0))
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return -EPROBE_DEFER;
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cpumask_set_cpu(0, &mask_val);
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cdev = cpufreq_cooling_register(&mask_val);
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if (IS_ERR(cdev)) {
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dev_err(&pdev->dev, "Failed to register cooling device\n");
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return PTR_ERR(cdev);
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}
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platform_set_drvdata(pdev, cdev);
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dev_info(&pdev->dev, "Cooling device registered: %s\n", cdev->type);
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return 0;
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}
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static int db8500_cpufreq_cooling_remove(struct platform_device *pdev)
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{
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struct thermal_cooling_device *cdev = platform_get_drvdata(pdev);
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cpufreq_cooling_unregister(cdev);
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return 0;
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}
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static int db8500_cpufreq_cooling_suspend(struct platform_device *pdev,
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pm_message_t state)
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{
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return -ENOSYS;
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}
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static int db8500_cpufreq_cooling_resume(struct platform_device *pdev)
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{
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return -ENOSYS;
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}
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#ifdef CONFIG_OF
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static const struct of_device_id db8500_cpufreq_cooling_match[] = {
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{ .compatible = "stericsson,db8500-cpufreq-cooling" },
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{},
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};
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#endif
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static struct platform_driver db8500_cpufreq_cooling_driver = {
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.driver = {
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.owner = THIS_MODULE,
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.name = "db8500-cpufreq-cooling",
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.of_match_table = of_match_ptr(db8500_cpufreq_cooling_match),
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},
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.probe = db8500_cpufreq_cooling_probe,
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.suspend = db8500_cpufreq_cooling_suspend,
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.resume = db8500_cpufreq_cooling_resume,
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.remove = db8500_cpufreq_cooling_remove,
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};
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static int __init db8500_cpufreq_cooling_init(void)
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{
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return platform_driver_register(&db8500_cpufreq_cooling_driver);
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}
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static void __exit db8500_cpufreq_cooling_exit(void)
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{
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platform_driver_unregister(&db8500_cpufreq_cooling_driver);
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}
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/* Should be later than db8500_cpufreq_register */
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late_initcall(db8500_cpufreq_cooling_init);
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module_exit(db8500_cpufreq_cooling_exit);
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MODULE_AUTHOR("Hongbo Zhang <hongbo.zhang@stericsson.com>");
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MODULE_DESCRIPTION("DB8500 cpufreq cooling driver");
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MODULE_LICENSE("GPL");
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