170 lines
4.0 KiB
C
170 lines
4.0 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* Copyright (c) 2016 Yang Ling <gnaygnil@gmail.com>
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*/
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#include <linux/clk.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/watchdog.h>
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/* Loongson 1 Watchdog Register Definitions */
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#define WDT_EN 0x0
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#define WDT_TIMER 0x4
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#define WDT_SET 0x8
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#define DEFAULT_HEARTBEAT 30
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static bool nowayout = WATCHDOG_NOWAYOUT;
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module_param(nowayout, bool, 0444);
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static unsigned int heartbeat;
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module_param(heartbeat, uint, 0444);
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struct ls1x_wdt_drvdata {
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void __iomem *base;
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struct clk *clk;
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unsigned long clk_rate;
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struct watchdog_device wdt;
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};
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static int ls1x_wdt_ping(struct watchdog_device *wdt_dev)
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{
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struct ls1x_wdt_drvdata *drvdata = watchdog_get_drvdata(wdt_dev);
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writel(0x1, drvdata->base + WDT_SET);
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return 0;
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}
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static int ls1x_wdt_set_timeout(struct watchdog_device *wdt_dev,
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unsigned int timeout)
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{
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struct ls1x_wdt_drvdata *drvdata = watchdog_get_drvdata(wdt_dev);
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unsigned int max_hw_heartbeat = wdt_dev->max_hw_heartbeat_ms / 1000;
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unsigned int counts;
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wdt_dev->timeout = timeout;
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counts = drvdata->clk_rate * min(timeout, max_hw_heartbeat);
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writel(counts, drvdata->base + WDT_TIMER);
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return 0;
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}
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static int ls1x_wdt_start(struct watchdog_device *wdt_dev)
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{
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struct ls1x_wdt_drvdata *drvdata = watchdog_get_drvdata(wdt_dev);
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writel(0x1, drvdata->base + WDT_EN);
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return 0;
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}
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static int ls1x_wdt_stop(struct watchdog_device *wdt_dev)
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{
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struct ls1x_wdt_drvdata *drvdata = watchdog_get_drvdata(wdt_dev);
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writel(0x0, drvdata->base + WDT_EN);
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return 0;
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}
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static int ls1x_wdt_restart(struct watchdog_device *wdt_dev,
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unsigned long action, void *data)
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{
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struct ls1x_wdt_drvdata *drvdata = watchdog_get_drvdata(wdt_dev);
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writel(0x1, drvdata->base + WDT_EN);
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writel(0x1, drvdata->base + WDT_TIMER);
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writel(0x1, drvdata->base + WDT_SET);
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return 0;
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}
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static const struct watchdog_info ls1x_wdt_info = {
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.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
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.identity = "Loongson1 Watchdog",
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};
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static const struct watchdog_ops ls1x_wdt_ops = {
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.owner = THIS_MODULE,
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.start = ls1x_wdt_start,
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.stop = ls1x_wdt_stop,
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.ping = ls1x_wdt_ping,
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.set_timeout = ls1x_wdt_set_timeout,
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.restart = ls1x_wdt_restart,
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};
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static int ls1x_wdt_probe(struct platform_device *pdev)
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{
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struct device *dev = &pdev->dev;
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struct ls1x_wdt_drvdata *drvdata;
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struct watchdog_device *ls1x_wdt;
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unsigned long clk_rate;
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int err;
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drvdata = devm_kzalloc(dev, sizeof(*drvdata), GFP_KERNEL);
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if (!drvdata)
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return -ENOMEM;
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drvdata->base = devm_platform_ioremap_resource(pdev, 0);
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if (IS_ERR(drvdata->base))
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return PTR_ERR(drvdata->base);
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drvdata->clk = devm_clk_get_enabled(dev, NULL);
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if (IS_ERR(drvdata->clk))
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return PTR_ERR(drvdata->clk);
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clk_rate = clk_get_rate(drvdata->clk);
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if (!clk_rate)
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return -EINVAL;
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drvdata->clk_rate = clk_rate;
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ls1x_wdt = &drvdata->wdt;
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ls1x_wdt->info = &ls1x_wdt_info;
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ls1x_wdt->ops = &ls1x_wdt_ops;
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ls1x_wdt->timeout = DEFAULT_HEARTBEAT;
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ls1x_wdt->min_timeout = 1;
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ls1x_wdt->max_hw_heartbeat_ms = U32_MAX / clk_rate * 1000;
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ls1x_wdt->parent = dev;
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watchdog_init_timeout(ls1x_wdt, heartbeat, dev);
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watchdog_set_nowayout(ls1x_wdt, nowayout);
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watchdog_set_drvdata(ls1x_wdt, drvdata);
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err = devm_watchdog_register_device(dev, &drvdata->wdt);
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if (err)
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return err;
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platform_set_drvdata(pdev, drvdata);
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dev_info(dev, "Loongson1 Watchdog driver registered\n");
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return 0;
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}
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#ifdef CONFIG_OF
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static const struct of_device_id ls1x_wdt_dt_ids[] = {
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{ .compatible = "loongson,ls1b-wdt", },
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{ .compatible = "loongson,ls1c-wdt", },
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{ /* sentinel */ }
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};
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MODULE_DEVICE_TABLE(of, ls1x_wdt_dt_ids);
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#endif
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static struct platform_driver ls1x_wdt_driver = {
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.probe = ls1x_wdt_probe,
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.driver = {
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.name = "ls1x-wdt",
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.of_match_table = of_match_ptr(ls1x_wdt_dt_ids),
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},
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};
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module_platform_driver(ls1x_wdt_driver);
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MODULE_AUTHOR("Yang Ling <gnaygnil@gmail.com>");
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MODULE_DESCRIPTION("Loongson1 Watchdog Driver");
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MODULE_LICENSE("GPL");
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