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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/20230727070051.17778-53-frank.li@vivo.com Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
162 lines
4.2 KiB
C
162 lines
4.2 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* Copyright (C) 2014 Linaro Ltd
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*
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* Author: Ulf Hansson <ulf.hansson@linaro.org>
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*
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* Simple MMC power sequence management
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*/
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#include <linux/clk.h>
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#include <linux/init.h>
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#include <linux/kernel.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/delay.h>
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#include <linux/property.h>
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#include <linux/mmc/host.h>
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#include "pwrseq.h"
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struct mmc_pwrseq_simple {
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struct mmc_pwrseq pwrseq;
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bool clk_enabled;
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u32 post_power_on_delay_ms;
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u32 power_off_delay_us;
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struct clk *ext_clk;
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struct gpio_descs *reset_gpios;
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};
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#define to_pwrseq_simple(p) container_of(p, struct mmc_pwrseq_simple, pwrseq)
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static void mmc_pwrseq_simple_set_gpios_value(struct mmc_pwrseq_simple *pwrseq,
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int value)
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{
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struct gpio_descs *reset_gpios = pwrseq->reset_gpios;
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if (!IS_ERR(reset_gpios)) {
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unsigned long *values;
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int nvalues = reset_gpios->ndescs;
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values = bitmap_alloc(nvalues, GFP_KERNEL);
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if (!values)
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return;
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if (value)
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bitmap_fill(values, nvalues);
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else
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bitmap_zero(values, nvalues);
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gpiod_set_array_value_cansleep(nvalues, reset_gpios->desc,
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reset_gpios->info, values);
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bitmap_free(values);
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}
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}
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static void mmc_pwrseq_simple_pre_power_on(struct mmc_host *host)
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{
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struct mmc_pwrseq_simple *pwrseq = to_pwrseq_simple(host->pwrseq);
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if (!IS_ERR(pwrseq->ext_clk) && !pwrseq->clk_enabled) {
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clk_prepare_enable(pwrseq->ext_clk);
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pwrseq->clk_enabled = true;
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}
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mmc_pwrseq_simple_set_gpios_value(pwrseq, 1);
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}
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static void mmc_pwrseq_simple_post_power_on(struct mmc_host *host)
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{
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struct mmc_pwrseq_simple *pwrseq = to_pwrseq_simple(host->pwrseq);
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mmc_pwrseq_simple_set_gpios_value(pwrseq, 0);
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if (pwrseq->post_power_on_delay_ms)
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msleep(pwrseq->post_power_on_delay_ms);
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}
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static void mmc_pwrseq_simple_power_off(struct mmc_host *host)
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{
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struct mmc_pwrseq_simple *pwrseq = to_pwrseq_simple(host->pwrseq);
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mmc_pwrseq_simple_set_gpios_value(pwrseq, 1);
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if (pwrseq->power_off_delay_us)
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usleep_range(pwrseq->power_off_delay_us,
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2 * pwrseq->power_off_delay_us);
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if (!IS_ERR(pwrseq->ext_clk) && pwrseq->clk_enabled) {
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clk_disable_unprepare(pwrseq->ext_clk);
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pwrseq->clk_enabled = false;
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}
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}
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static const struct mmc_pwrseq_ops mmc_pwrseq_simple_ops = {
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.pre_power_on = mmc_pwrseq_simple_pre_power_on,
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.post_power_on = mmc_pwrseq_simple_post_power_on,
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.power_off = mmc_pwrseq_simple_power_off,
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};
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static const struct of_device_id mmc_pwrseq_simple_of_match[] = {
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{ .compatible = "mmc-pwrseq-simple",},
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{/* sentinel */},
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};
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MODULE_DEVICE_TABLE(of, mmc_pwrseq_simple_of_match);
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static int mmc_pwrseq_simple_probe(struct platform_device *pdev)
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{
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struct mmc_pwrseq_simple *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->ext_clk = devm_clk_get(dev, "ext_clock");
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if (IS_ERR(pwrseq->ext_clk) && PTR_ERR(pwrseq->ext_clk) != -ENOENT)
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return dev_err_probe(dev, PTR_ERR(pwrseq->ext_clk), "external clock not ready\n");
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pwrseq->reset_gpios = devm_gpiod_get_array(dev, "reset",
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GPIOD_OUT_HIGH);
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if (IS_ERR(pwrseq->reset_gpios) &&
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PTR_ERR(pwrseq->reset_gpios) != -ENOENT &&
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PTR_ERR(pwrseq->reset_gpios) != -ENOSYS) {
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return dev_err_probe(dev, PTR_ERR(pwrseq->reset_gpios), "reset GPIOs not ready\n");
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}
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device_property_read_u32(dev, "post-power-on-delay-ms",
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&pwrseq->post_power_on_delay_ms);
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device_property_read_u32(dev, "power-off-delay-us",
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&pwrseq->power_off_delay_us);
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pwrseq->pwrseq.dev = dev;
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pwrseq->pwrseq.ops = &mmc_pwrseq_simple_ops;
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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_simple_remove(struct platform_device *pdev)
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{
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struct mmc_pwrseq_simple *pwrseq = platform_get_drvdata(pdev);
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mmc_pwrseq_unregister(&pwrseq->pwrseq);
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}
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static struct platform_driver mmc_pwrseq_simple_driver = {
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.probe = mmc_pwrseq_simple_probe,
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.remove_new = mmc_pwrseq_simple_remove,
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.driver = {
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.name = "pwrseq_simple",
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.of_match_table = mmc_pwrseq_simple_of_match,
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},
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};
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module_platform_driver(mmc_pwrseq_simple_driver);
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MODULE_LICENSE("GPL v2");
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