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![Uwe Kleine-König](/assets/img/avatar_default.png)
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. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
92 lines
2.7 KiB
C
92 lines
2.7 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* Intel Low Power Subsystem PWM controller driver
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*
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* Copyright (C) 2014, Intel Corporation
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*
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* Derived from the original pwm-lpss.c
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*/
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#include <linux/kernel.h>
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#include <linux/mod_devicetable.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_runtime.h>
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#include <linux/property.h>
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#include "pwm-lpss.h"
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static int pwm_lpss_probe_platform(struct platform_device *pdev)
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{
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const struct pwm_lpss_boardinfo *info;
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struct pwm_lpss_chip *lpwm;
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void __iomem *base;
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info = device_get_match_data(&pdev->dev);
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if (!info)
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return -ENODEV;
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base = devm_platform_ioremap_resource(pdev, 0);
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if (IS_ERR(base))
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return PTR_ERR(base);
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lpwm = devm_pwm_lpss_probe(&pdev->dev, base, info);
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if (IS_ERR(lpwm))
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return PTR_ERR(lpwm);
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platform_set_drvdata(pdev, lpwm);
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/*
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* On Cherry Trail devices the GFX0._PS0 AML checks if the controller
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* is on and if it is not on it turns it on and restores what it
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* believes is the correct state to the PWM controller.
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* Because of this we must disallow direct-complete, which keeps the
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* controller (runtime)suspended on resume, to avoid 2 issues:
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* 1. The controller getting turned on without the linux-pm code
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* knowing about this. On devices where the controller is unused
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* this causes it to stay on during the next suspend causing high
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* battery drain (because S0i3 is not reached)
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* 2. The state restoring code unexpectedly messing with the controller
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*
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* Leaving the controller runtime-suspended (skipping runtime-resume +
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* normal-suspend) during suspend is fine.
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*/
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if (info->other_devices_aml_touches_pwm_regs)
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dev_pm_set_driver_flags(&pdev->dev, DPM_FLAG_NO_DIRECT_COMPLETE|
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DPM_FLAG_SMART_SUSPEND);
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pm_runtime_set_active(&pdev->dev);
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pm_runtime_enable(&pdev->dev);
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return 0;
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}
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static void pwm_lpss_remove_platform(struct platform_device *pdev)
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{
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pm_runtime_disable(&pdev->dev);
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}
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static const struct acpi_device_id pwm_lpss_acpi_match[] = {
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{ "80860F09", (unsigned long)&pwm_lpss_byt_info },
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{ "80862288", (unsigned long)&pwm_lpss_bsw_info },
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{ "80862289", (unsigned long)&pwm_lpss_bsw_info },
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{ "80865AC8", (unsigned long)&pwm_lpss_bxt_info },
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{ },
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};
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MODULE_DEVICE_TABLE(acpi, pwm_lpss_acpi_match);
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static struct platform_driver pwm_lpss_driver_platform = {
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.driver = {
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.name = "pwm-lpss",
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.acpi_match_table = pwm_lpss_acpi_match,
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},
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.probe = pwm_lpss_probe_platform,
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.remove_new = pwm_lpss_remove_platform,
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};
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module_platform_driver(pwm_lpss_driver_platform);
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MODULE_DESCRIPTION("PWM platform driver for Intel LPSS");
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MODULE_LICENSE("GPL v2");
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MODULE_IMPORT_NS(PWM_LPSS);
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MODULE_ALIAS("platform:pwm-lpss");
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