157 lines
		
	
	
		
			3.6 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			157 lines
		
	
	
		
			3.6 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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| 
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| #include <linux/clk.h>
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| #include <linux/module.h>
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| #include <linux/platform_device.h>
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| #include <linux/watchdog.h>
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| #include <loongson1.h>
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| 
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| #define DEFAULT_HEARTBEAT	30
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| 
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| static bool nowayout = WATCHDOG_NOWAYOUT;
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| module_param(nowayout, bool, 0444);
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| 
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| static unsigned int heartbeat;
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| module_param(heartbeat, uint, 0444);
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| 
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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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| 
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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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| 
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| 	writel(0x1, drvdata->base + WDT_SET);
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| 
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| 	return 0;
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| }
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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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| 
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| 	wdt_dev->timeout = timeout;
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| 
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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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| 
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| 	return 0;
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| }
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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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| 
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| 	writel(0x1, drvdata->base + WDT_EN);
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| 
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| 	return 0;
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| }
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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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| 
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| 	writel(0x0, drvdata->base + WDT_EN);
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| 
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| 	return 0;
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| }
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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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| 
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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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| };
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| 
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| static void ls1x_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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| 
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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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| 
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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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| 
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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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| 
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| 	drvdata->clk = devm_clk_get(dev, pdev->name);
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| 	if (IS_ERR(drvdata->clk))
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| 		return PTR_ERR(drvdata->clk);
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| 
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| 	err = clk_prepare_enable(drvdata->clk);
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| 	if (err) {
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| 		dev_err(dev, "clk enable failed\n");
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| 		return err;
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| 	}
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| 	err = devm_add_action_or_reset(dev, ls1x_clk_disable_unprepare,
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| 				       drvdata->clk);
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| 	if (err)
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| 		return err;
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| 
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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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| 
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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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| 
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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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| 
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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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| 
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| 	platform_set_drvdata(pdev, drvdata);
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| 
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| 	dev_info(dev, "Loongson1 Watchdog driver registered\n");
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| 
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| 	return 0;
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| }
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| 
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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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| 	},
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| };
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| 
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| module_platform_driver(ls1x_wdt_driver);
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| 
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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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