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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> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
157 lines
3.8 KiB
C
157 lines
3.8 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* CPU frequency scaling for DaVinci
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*
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* Copyright (C) 2009 Texas Instruments Incorporated - https://www.ti.com/
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*
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* Based on linux/arch/arm/plat-omap/cpu-omap.c. Original Copyright follows:
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*
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* Copyright (C) 2005 Nokia Corporation
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* Written by Tony Lindgren <tony@atomide.com>
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*
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* Based on cpu-sa1110.c, Copyright (C) 2001 Russell King
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*
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* Copyright (C) 2007-2008 Texas Instruments, Inc.
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* Updated to support OMAP3
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* Rajendra Nayak <rnayak@ti.com>
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*/
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#include <linux/types.h>
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#include <linux/cpufreq.h>
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#include <linux/init.h>
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#include <linux/err.h>
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#include <linux/clk.h>
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#include <linux/platform_data/davinci-cpufreq.h>
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#include <linux/platform_device.h>
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#include <linux/export.h>
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struct davinci_cpufreq {
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struct device *dev;
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struct clk *armclk;
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struct clk *asyncclk;
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unsigned long asyncrate;
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};
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static struct davinci_cpufreq cpufreq;
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static int davinci_target(struct cpufreq_policy *policy, unsigned int idx)
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{
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struct davinci_cpufreq_config *pdata = cpufreq.dev->platform_data;
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struct clk *armclk = cpufreq.armclk;
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unsigned int old_freq, new_freq;
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int ret = 0;
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old_freq = policy->cur;
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new_freq = pdata->freq_table[idx].frequency;
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/* if moving to higher frequency, up the voltage beforehand */
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if (pdata->set_voltage && new_freq > old_freq) {
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ret = pdata->set_voltage(idx);
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if (ret)
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return ret;
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}
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ret = clk_set_rate(armclk, new_freq * 1000);
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if (ret)
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return ret;
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if (cpufreq.asyncclk) {
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ret = clk_set_rate(cpufreq.asyncclk, cpufreq.asyncrate);
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if (ret)
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return ret;
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}
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/* if moving to lower freq, lower the voltage after lowering freq */
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if (pdata->set_voltage && new_freq < old_freq)
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pdata->set_voltage(idx);
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return 0;
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}
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static int davinci_cpu_init(struct cpufreq_policy *policy)
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{
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int result = 0;
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struct davinci_cpufreq_config *pdata = cpufreq.dev->platform_data;
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struct cpufreq_frequency_table *freq_table = pdata->freq_table;
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if (policy->cpu != 0)
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return -EINVAL;
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/* Finish platform specific initialization */
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if (pdata->init) {
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result = pdata->init();
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if (result)
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return result;
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}
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policy->clk = cpufreq.armclk;
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/*
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* Time measurement across the target() function yields ~1500-1800us
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* time taken with no drivers on notification list.
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* Setting the latency to 2000 us to accommodate addition of drivers
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* to pre/post change notification list.
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*/
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cpufreq_generic_init(policy, freq_table, 2000 * 1000);
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return 0;
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}
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static struct cpufreq_driver davinci_driver = {
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.flags = CPUFREQ_NEED_INITIAL_FREQ_CHECK,
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.verify = cpufreq_generic_frequency_table_verify,
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.target_index = davinci_target,
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.get = cpufreq_generic_get,
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.init = davinci_cpu_init,
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.name = "davinci",
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.attr = cpufreq_generic_attr,
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};
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static int __init davinci_cpufreq_probe(struct platform_device *pdev)
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{
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struct davinci_cpufreq_config *pdata = pdev->dev.platform_data;
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struct clk *asyncclk;
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if (!pdata)
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return -EINVAL;
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if (!pdata->freq_table)
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return -EINVAL;
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cpufreq.dev = &pdev->dev;
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cpufreq.armclk = clk_get(NULL, "arm");
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if (IS_ERR(cpufreq.armclk)) {
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dev_err(cpufreq.dev, "Unable to get ARM clock\n");
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return PTR_ERR(cpufreq.armclk);
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}
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asyncclk = clk_get(cpufreq.dev, "async");
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if (!IS_ERR(asyncclk)) {
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cpufreq.asyncclk = asyncclk;
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cpufreq.asyncrate = clk_get_rate(asyncclk);
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}
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return cpufreq_register_driver(&davinci_driver);
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}
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static void __exit davinci_cpufreq_remove(struct platform_device *pdev)
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{
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cpufreq_unregister_driver(&davinci_driver);
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clk_put(cpufreq.armclk);
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if (cpufreq.asyncclk)
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clk_put(cpufreq.asyncclk);
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}
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static struct platform_driver davinci_cpufreq_driver = {
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.driver = {
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.name = "cpufreq-davinci",
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},
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.remove_new = __exit_p(davinci_cpufreq_remove),
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};
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int __init davinci_cpufreq_init(void)
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{
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return platform_driver_probe(&davinci_cpufreq_driver,
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davinci_cpufreq_probe);
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}
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