![Guenter Roeck](/assets/img/avatar_default.png)
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 empty remove function - Use devm_add_action_or_reset() for calls to clk_disable_unprepare - Use local variable 'struct device *dev' consistently - Use devm_watchdog_register_driver() to register watchdog device - Replace shutdown function with call to watchdog_stop_on_reboot() Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>
219 lines
5 KiB
C
219 lines
5 KiB
C
// SPDX-License-Identifier: GPL-2.0+
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/*
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* Copyright (C) 2015 Broadcom Corporation
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*
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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/io.h>
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#include <linux/module.h>
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#include <linux/of.h>
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#include <linux/platform_device.h>
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#include <linux/pm.h>
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#include <linux/watchdog.h>
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#define WDT_START_1 0xff00
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#define WDT_START_2 0x00ff
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#define WDT_STOP_1 0xee00
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#define WDT_STOP_2 0x00ee
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#define WDT_TIMEOUT_REG 0x0
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#define WDT_CMD_REG 0x4
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#define WDT_MIN_TIMEOUT 1 /* seconds */
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#define WDT_DEFAULT_TIMEOUT 30 /* seconds */
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#define WDT_DEFAULT_RATE 27000000
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struct bcm7038_watchdog {
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void __iomem *base;
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struct watchdog_device wdd;
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u32 rate;
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struct clk *clk;
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};
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static bool nowayout = WATCHDOG_NOWAYOUT;
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static void bcm7038_wdt_set_timeout_reg(struct watchdog_device *wdog)
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{
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struct bcm7038_watchdog *wdt = watchdog_get_drvdata(wdog);
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u32 timeout;
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timeout = wdt->rate * wdog->timeout;
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writel(timeout, wdt->base + WDT_TIMEOUT_REG);
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}
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static int bcm7038_wdt_ping(struct watchdog_device *wdog)
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{
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struct bcm7038_watchdog *wdt = watchdog_get_drvdata(wdog);
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writel(WDT_START_1, wdt->base + WDT_CMD_REG);
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writel(WDT_START_2, wdt->base + WDT_CMD_REG);
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return 0;
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}
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static int bcm7038_wdt_start(struct watchdog_device *wdog)
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{
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bcm7038_wdt_set_timeout_reg(wdog);
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bcm7038_wdt_ping(wdog);
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return 0;
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}
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static int bcm7038_wdt_stop(struct watchdog_device *wdog)
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{
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struct bcm7038_watchdog *wdt = watchdog_get_drvdata(wdog);
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writel(WDT_STOP_1, wdt->base + WDT_CMD_REG);
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writel(WDT_STOP_2, wdt->base + WDT_CMD_REG);
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return 0;
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}
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static int bcm7038_wdt_set_timeout(struct watchdog_device *wdog,
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unsigned int t)
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{
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/* Can't modify timeout value if watchdog timer is running */
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bcm7038_wdt_stop(wdog);
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wdog->timeout = t;
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bcm7038_wdt_start(wdog);
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return 0;
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}
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static unsigned int bcm7038_wdt_get_timeleft(struct watchdog_device *wdog)
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{
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struct bcm7038_watchdog *wdt = watchdog_get_drvdata(wdog);
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u32 time_left;
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time_left = readl(wdt->base + WDT_CMD_REG);
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return time_left / wdt->rate;
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}
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static const struct watchdog_info bcm7038_wdt_info = {
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.identity = "Broadcom BCM7038 Watchdog Timer",
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.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING |
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WDIOF_MAGICCLOSE
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};
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static const struct watchdog_ops bcm7038_wdt_ops = {
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.owner = THIS_MODULE,
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.start = bcm7038_wdt_start,
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.stop = bcm7038_wdt_stop,
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.set_timeout = bcm7038_wdt_set_timeout,
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.get_timeleft = bcm7038_wdt_get_timeleft,
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};
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static void bcm7038_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 bcm7038_wdt_probe(struct platform_device *pdev)
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{
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struct device *dev = &pdev->dev;
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struct bcm7038_watchdog *wdt;
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int err;
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wdt = devm_kzalloc(dev, sizeof(*wdt), GFP_KERNEL);
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if (!wdt)
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return -ENOMEM;
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platform_set_drvdata(pdev, wdt);
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wdt->base = devm_platform_ioremap_resource(pdev, 0);
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if (IS_ERR(wdt->base))
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return PTR_ERR(wdt->base);
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wdt->clk = devm_clk_get(dev, NULL);
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/* If unable to get clock, use default frequency */
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if (!IS_ERR(wdt->clk)) {
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err = clk_prepare_enable(wdt->clk);
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if (err)
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return err;
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err = devm_add_action_or_reset(dev,
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bcm7038_clk_disable_unprepare,
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wdt->clk);
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if (err)
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return err;
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wdt->rate = clk_get_rate(wdt->clk);
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/* Prevent divide-by-zero exception */
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if (!wdt->rate)
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wdt->rate = WDT_DEFAULT_RATE;
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} else {
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wdt->rate = WDT_DEFAULT_RATE;
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wdt->clk = NULL;
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}
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wdt->wdd.info = &bcm7038_wdt_info;
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wdt->wdd.ops = &bcm7038_wdt_ops;
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wdt->wdd.min_timeout = WDT_MIN_TIMEOUT;
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wdt->wdd.timeout = WDT_DEFAULT_TIMEOUT;
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wdt->wdd.max_timeout = 0xffffffff / wdt->rate;
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wdt->wdd.parent = dev;
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watchdog_set_drvdata(&wdt->wdd, wdt);
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watchdog_stop_on_reboot(&wdt->wdd);
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watchdog_stop_on_unregister(&wdt->wdd);
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err = devm_watchdog_register_device(dev, &wdt->wdd);
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if (err) {
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dev_err(dev, "Failed to register watchdog device\n");
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return err;
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}
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dev_info(dev, "Registered BCM7038 Watchdog\n");
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return 0;
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}
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#ifdef CONFIG_PM_SLEEP
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static int bcm7038_wdt_suspend(struct device *dev)
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{
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struct bcm7038_watchdog *wdt = dev_get_drvdata(dev);
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if (watchdog_active(&wdt->wdd))
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return bcm7038_wdt_stop(&wdt->wdd);
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return 0;
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}
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static int bcm7038_wdt_resume(struct device *dev)
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{
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struct bcm7038_watchdog *wdt = dev_get_drvdata(dev);
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if (watchdog_active(&wdt->wdd))
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return bcm7038_wdt_start(&wdt->wdd);
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return 0;
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}
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#endif
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static SIMPLE_DEV_PM_OPS(bcm7038_wdt_pm_ops, bcm7038_wdt_suspend,
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bcm7038_wdt_resume);
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static const struct of_device_id bcm7038_wdt_match[] = {
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{ .compatible = "brcm,bcm7038-wdt" },
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{},
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};
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MODULE_DEVICE_TABLE(of, bcm7038_wdt_match);
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static struct platform_driver bcm7038_wdt_driver = {
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.probe = bcm7038_wdt_probe,
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.driver = {
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.name = "bcm7038-wdt",
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.of_match_table = bcm7038_wdt_match,
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.pm = &bcm7038_wdt_pm_ops,
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}
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};
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module_platform_driver(bcm7038_wdt_driver);
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module_param(nowayout, bool, 0);
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MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
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__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
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MODULE_LICENSE("GPL");
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MODULE_DESCRIPTION("Driver for Broadcom 7038 SoCs Watchdog");
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MODULE_AUTHOR("Justin Chen");
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