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https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
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46ebd4d865
The .remove() callback for a platform driver returns an int which makes many driver authors wrongly assume it's possible to do error handling by returning an error code. However the value returned is (mostly) ignored and this typically results in resource leaks. To improve here there is a quest to make the remove callback return void. In the first step of this quest all drivers are converted to .remove_new() which already returns void. Trivially convert this driver from always returning zero in the remove callback to the void returning variant. Cc: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Yangtao Li <frank.li@vivo.com> Reviewed-by: Florian Fainelli <florian.fainelli@broadcom.com> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
95 lines
2.3 KiB
C
95 lines
2.3 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Raspberry Pi cpufreq driver
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*
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* Copyright (C) 2019, Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
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*/
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#include <linux/clk.h>
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#include <linux/cpu.h>
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#include <linux/cpufreq.h>
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#include <linux/module.h>
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#include <linux/platform_device.h>
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#include <linux/pm_opp.h>
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#define RASPBERRYPI_FREQ_INTERVAL 100000000
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static struct platform_device *cpufreq_dt;
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static int raspberrypi_cpufreq_probe(struct platform_device *pdev)
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{
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struct device *cpu_dev;
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unsigned long min, max;
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unsigned long rate;
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struct clk *clk;
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int ret;
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cpu_dev = get_cpu_device(0);
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if (!cpu_dev) {
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pr_err("Cannot get CPU for cpufreq driver\n");
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return -ENODEV;
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}
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clk = clk_get(cpu_dev, NULL);
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if (IS_ERR(clk)) {
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dev_err(cpu_dev, "Cannot get clock for CPU0\n");
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return PTR_ERR(clk);
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}
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/*
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* The max and min frequencies are configurable in the Raspberry Pi
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* firmware, so we query them at runtime.
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*/
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min = roundup(clk_round_rate(clk, 0), RASPBERRYPI_FREQ_INTERVAL);
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max = roundup(clk_round_rate(clk, ULONG_MAX), RASPBERRYPI_FREQ_INTERVAL);
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clk_put(clk);
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for (rate = min; rate <= max; rate += RASPBERRYPI_FREQ_INTERVAL) {
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ret = dev_pm_opp_add(cpu_dev, rate, 0);
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if (ret)
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goto remove_opp;
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}
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cpufreq_dt = platform_device_register_simple("cpufreq-dt", -1, NULL, 0);
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ret = PTR_ERR_OR_ZERO(cpufreq_dt);
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if (ret) {
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dev_err(cpu_dev, "Failed to create platform device, %d\n", ret);
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goto remove_opp;
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}
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return 0;
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remove_opp:
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dev_pm_opp_remove_all_dynamic(cpu_dev);
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return ret;
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}
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static void raspberrypi_cpufreq_remove(struct platform_device *pdev)
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{
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struct device *cpu_dev;
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cpu_dev = get_cpu_device(0);
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if (cpu_dev)
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dev_pm_opp_remove_all_dynamic(cpu_dev);
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platform_device_unregister(cpufreq_dt);
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}
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/*
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* Since the driver depends on clk-raspberrypi, which may return EPROBE_DEFER,
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* all the activity is performed in the probe, which may be defered as well.
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*/
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static struct platform_driver raspberrypi_cpufreq_driver = {
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.driver = {
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.name = "raspberrypi-cpufreq",
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},
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.probe = raspberrypi_cpufreq_probe,
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.remove_new = raspberrypi_cpufreq_remove,
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};
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module_platform_driver(raspberrypi_cpufreq_driver);
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MODULE_AUTHOR("Nicolas Saenz Julienne <nsaenzjulienne@suse.de");
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MODULE_DESCRIPTION("Raspberry Pi cpufreq driver");
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MODULE_LICENSE("GPL");
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MODULE_ALIAS("platform:raspberrypi-cpufreq");
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