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c838a3ae61
Use device managed functions to simplify error handling, reduce source code size, improve readability, and reduce the likelyhood of bugs. Other improvements as listed below. The conversion was done automatically with coccinelle using the following semantic patches. The semantic patches and the scripts used to generate this commit log are available at https://github.com/groeck/coccinelle-patches - Drop assignments to otherwise unused variables - Drop unnecessary braces around conditional return statements - Drop empty remove function - Use devm_add_action_or_reset() for calls to clk_disable_unprepare - Replace stop on remove with call to watchdog_stop_on_unregister() - Use devm_watchdog_register_driver() to register watchdog device Cc: Marc Gonzalez <marc.w.gonzalez@free.fr> Cc: Mans Rullgard <mans@mansr.com> Signed-off-by: Guenter Roeck <linux@roeck-us.net> Acked-by: Mans Rullgard <mans@mansr.com> Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>
210 lines
4.8 KiB
C
210 lines
4.8 KiB
C
// SPDX-License-Identifier: GPL-2.0+
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/*
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* Copyright (C) 2015 Mans Rullgard <mans@mansr.com>
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* SMP86xx/SMP87xx Watchdog driver
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*/
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#include <linux/bitops.h>
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#include <linux/clk.h>
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#include <linux/delay.h>
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#include <linux/io.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/moduleparam.h>
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#include <linux/mod_devicetable.h>
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#include <linux/platform_device.h>
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#include <linux/watchdog.h>
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#define DEFAULT_TIMEOUT 30
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static bool nowayout = WATCHDOG_NOWAYOUT;
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module_param(nowayout, bool, 0);
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MODULE_PARM_DESC(nowayout,
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"Watchdog cannot be stopped once started (default="
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__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
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static unsigned int timeout;
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module_param(timeout, int, 0);
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MODULE_PARM_DESC(timeout, "Watchdog timeout");
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/*
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* Counter counts down from programmed value. Reset asserts when
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* the counter reaches 1.
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*/
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#define WD_COUNTER 0
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#define WD_CONFIG 4
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#define WD_CONFIG_XTAL_IN BIT(0)
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#define WD_CONFIG_DISABLE BIT(31)
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struct tangox_wdt_device {
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struct watchdog_device wdt;
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void __iomem *base;
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unsigned long clk_rate;
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struct clk *clk;
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};
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static int tangox_wdt_set_timeout(struct watchdog_device *wdt,
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unsigned int new_timeout)
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{
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wdt->timeout = new_timeout;
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return 0;
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}
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static int tangox_wdt_start(struct watchdog_device *wdt)
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{
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struct tangox_wdt_device *dev = watchdog_get_drvdata(wdt);
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u32 ticks;
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ticks = 1 + wdt->timeout * dev->clk_rate;
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writel(ticks, dev->base + WD_COUNTER);
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return 0;
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}
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static int tangox_wdt_stop(struct watchdog_device *wdt)
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{
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struct tangox_wdt_device *dev = watchdog_get_drvdata(wdt);
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writel(0, dev->base + WD_COUNTER);
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return 0;
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}
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static unsigned int tangox_wdt_get_timeleft(struct watchdog_device *wdt)
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{
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struct tangox_wdt_device *dev = watchdog_get_drvdata(wdt);
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u32 count;
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count = readl(dev->base + WD_COUNTER);
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if (!count)
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return 0;
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return (count - 1) / dev->clk_rate;
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}
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static const struct watchdog_info tangox_wdt_info = {
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.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
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.identity = "tangox watchdog",
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};
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static int tangox_wdt_restart(struct watchdog_device *wdt,
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unsigned long action, void *data)
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{
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struct tangox_wdt_device *dev = watchdog_get_drvdata(wdt);
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writel(1, dev->base + WD_COUNTER);
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return 0;
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}
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static const struct watchdog_ops tangox_wdt_ops = {
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.start = tangox_wdt_start,
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.stop = tangox_wdt_stop,
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.set_timeout = tangox_wdt_set_timeout,
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.get_timeleft = tangox_wdt_get_timeleft,
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.restart = tangox_wdt_restart,
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};
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static void tangox_clk_disable_unprepare(void *data)
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{
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clk_disable_unprepare(data);
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}
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static int tangox_wdt_probe(struct platform_device *pdev)
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{
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struct tangox_wdt_device *dev;
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u32 config;
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int err;
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dev = devm_kzalloc(&pdev->dev, sizeof(*dev), GFP_KERNEL);
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if (!dev)
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return -ENOMEM;
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dev->base = devm_platform_ioremap_resource(pdev, 0);
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if (IS_ERR(dev->base))
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return PTR_ERR(dev->base);
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dev->clk = devm_clk_get(&pdev->dev, NULL);
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if (IS_ERR(dev->clk))
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return PTR_ERR(dev->clk);
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err = clk_prepare_enable(dev->clk);
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if (err)
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return err;
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err = devm_add_action_or_reset(&pdev->dev,
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tangox_clk_disable_unprepare, dev->clk);
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if (err)
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return err;
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dev->clk_rate = clk_get_rate(dev->clk);
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if (!dev->clk_rate)
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return -EINVAL;
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dev->wdt.parent = &pdev->dev;
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dev->wdt.info = &tangox_wdt_info;
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dev->wdt.ops = &tangox_wdt_ops;
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dev->wdt.timeout = DEFAULT_TIMEOUT;
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dev->wdt.min_timeout = 1;
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dev->wdt.max_hw_heartbeat_ms = (U32_MAX - 1) / dev->clk_rate;
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watchdog_init_timeout(&dev->wdt, timeout, &pdev->dev);
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watchdog_set_nowayout(&dev->wdt, nowayout);
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watchdog_set_drvdata(&dev->wdt, dev);
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/*
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* Deactivate counter if disable bit is set to avoid
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* accidental reset.
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*/
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config = readl(dev->base + WD_CONFIG);
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if (config & WD_CONFIG_DISABLE)
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writel(0, dev->base + WD_COUNTER);
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writel(WD_CONFIG_XTAL_IN, dev->base + WD_CONFIG);
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/*
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* Mark as active and restart with configured timeout if
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* already running.
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*/
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if (readl(dev->base + WD_COUNTER)) {
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set_bit(WDOG_HW_RUNNING, &dev->wdt.status);
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tangox_wdt_start(&dev->wdt);
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}
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watchdog_set_restart_priority(&dev->wdt, 128);
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watchdog_stop_on_unregister(&dev->wdt);
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err = devm_watchdog_register_device(&pdev->dev, &dev->wdt);
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if (err)
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return err;
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platform_set_drvdata(pdev, dev);
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dev_info(&pdev->dev, "SMP86xx/SMP87xx watchdog registered\n");
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return 0;
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}
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static const struct of_device_id tangox_wdt_dt_ids[] = {
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{ .compatible = "sigma,smp8642-wdt" },
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{ .compatible = "sigma,smp8759-wdt" },
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{ }
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};
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MODULE_DEVICE_TABLE(of, tangox_wdt_dt_ids);
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static struct platform_driver tangox_wdt_driver = {
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.probe = tangox_wdt_probe,
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.driver = {
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.name = "tangox-wdt",
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.of_match_table = tangox_wdt_dt_ids,
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},
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};
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module_platform_driver(tangox_wdt_driver);
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MODULE_AUTHOR("Mans Rullgard <mans@mansr.com>");
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MODULE_DESCRIPTION("SMP86xx/SMP87xx Watchdog driver");
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MODULE_LICENSE("GPL");
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