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![Yangtao Li](/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. Cc: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Yangtao Li <frank.li@vivo.com> Link: https://lore.kernel.org/r/20230727070051.17778-55-frank.li@vivo.com Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
118 lines
3.1 KiB
C
118 lines
3.1 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* Copyright (C) 2015, Samsung Electronics Co., Ltd.
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*
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* Author: Marek Szyprowski <m.szyprowski@samsung.com>
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*
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* Simple eMMC hardware reset provider
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*/
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#include <linux/delay.h>
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#include <linux/kernel.h>
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#include <linux/init.h>
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#include <linux/platform_device.h>
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#include <linux/module.h>
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#include <linux/slab.h>
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#include <linux/device.h>
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#include <linux/err.h>
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#include <linux/gpio/consumer.h>
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#include <linux/reboot.h>
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#include <linux/mmc/host.h>
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#include "pwrseq.h"
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struct mmc_pwrseq_emmc {
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struct mmc_pwrseq pwrseq;
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struct notifier_block reset_nb;
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struct gpio_desc *reset_gpio;
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};
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#define to_pwrseq_emmc(p) container_of(p, struct mmc_pwrseq_emmc, pwrseq)
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static void mmc_pwrseq_emmc_reset(struct mmc_host *host)
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{
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struct mmc_pwrseq_emmc *pwrseq = to_pwrseq_emmc(host->pwrseq);
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gpiod_set_value_cansleep(pwrseq->reset_gpio, 1);
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udelay(1);
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gpiod_set_value_cansleep(pwrseq->reset_gpio, 0);
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udelay(200);
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}
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static int mmc_pwrseq_emmc_reset_nb(struct notifier_block *this,
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unsigned long mode, void *cmd)
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{
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struct mmc_pwrseq_emmc *pwrseq = container_of(this,
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struct mmc_pwrseq_emmc, reset_nb);
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gpiod_set_value(pwrseq->reset_gpio, 1);
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udelay(1);
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gpiod_set_value(pwrseq->reset_gpio, 0);
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udelay(200);
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return NOTIFY_DONE;
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}
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static const struct mmc_pwrseq_ops mmc_pwrseq_emmc_ops = {
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.reset = mmc_pwrseq_emmc_reset,
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};
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static int mmc_pwrseq_emmc_probe(struct platform_device *pdev)
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{
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struct mmc_pwrseq_emmc *pwrseq;
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struct device *dev = &pdev->dev;
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pwrseq = devm_kzalloc(dev, sizeof(*pwrseq), GFP_KERNEL);
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if (!pwrseq)
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return -ENOMEM;
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pwrseq->reset_gpio = devm_gpiod_get(dev, "reset", GPIOD_OUT_LOW);
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if (IS_ERR(pwrseq->reset_gpio))
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return PTR_ERR(pwrseq->reset_gpio);
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if (!gpiod_cansleep(pwrseq->reset_gpio)) {
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/*
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* register reset handler to ensure emmc reset also from
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* emergency_reboot(), priority 255 is the highest priority
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* so it will be executed before any system reboot handler.
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*/
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pwrseq->reset_nb.notifier_call = mmc_pwrseq_emmc_reset_nb;
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pwrseq->reset_nb.priority = 255;
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register_restart_handler(&pwrseq->reset_nb);
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} else {
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dev_notice(dev, "EMMC reset pin tied to a sleepy GPIO driver; reset on emergency-reboot disabled\n");
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}
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pwrseq->pwrseq.ops = &mmc_pwrseq_emmc_ops;
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pwrseq->pwrseq.dev = dev;
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pwrseq->pwrseq.owner = THIS_MODULE;
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platform_set_drvdata(pdev, pwrseq);
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return mmc_pwrseq_register(&pwrseq->pwrseq);
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}
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static void mmc_pwrseq_emmc_remove(struct platform_device *pdev)
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{
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struct mmc_pwrseq_emmc *pwrseq = platform_get_drvdata(pdev);
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unregister_restart_handler(&pwrseq->reset_nb);
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mmc_pwrseq_unregister(&pwrseq->pwrseq);
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}
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static const struct of_device_id mmc_pwrseq_emmc_of_match[] = {
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{ .compatible = "mmc-pwrseq-emmc",},
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{/* sentinel */},
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};
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MODULE_DEVICE_TABLE(of, mmc_pwrseq_emmc_of_match);
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static struct platform_driver mmc_pwrseq_emmc_driver = {
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.probe = mmc_pwrseq_emmc_probe,
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.remove_new = mmc_pwrseq_emmc_remove,
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.driver = {
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.name = "pwrseq_emmc",
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.of_match_table = mmc_pwrseq_emmc_of_match,
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},
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};
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module_platform_driver(mmc_pwrseq_emmc_driver);
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MODULE_LICENSE("GPL v2");
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