[linux-block.git] / drivers / watchdog / loongson1_wdt.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Copyright (c) 2016 Yang Ling <gnaygnil@gmail.com>
 */

#include <linux/clk.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/watchdog.h>

/* Loongson 1 Watchdog Register Definitions */
#define WDT_EN			0x0
#define WDT_TIMER		0x4
#define WDT_SET			0x8

#define DEFAULT_HEARTBEAT	30

static bool nowayout = WATCHDOG_NOWAYOUT;
module_param(nowayout, bool, 0444);

static unsigned int heartbeat;
module_param(heartbeat, uint, 0444);

struct ls1x_wdt_drvdata {
	void __iomem *base;
	struct clk *clk;
	unsigned long clk_rate;
	struct watchdog_device wdt;
};

static int ls1x_wdt_ping(struct watchdog_device *wdt_dev)
{
	struct ls1x_wdt_drvdata *drvdata = watchdog_get_drvdata(wdt_dev);

	writel(0x1, drvdata->base + WDT_SET);

	return 0;
}

static int ls1x_wdt_set_timeout(struct watchdog_device *wdt_dev,
				unsigned int timeout)
{
	struct ls1x_wdt_drvdata *drvdata = watchdog_get_drvdata(wdt_dev);
	unsigned int max_hw_heartbeat = wdt_dev->max_hw_heartbeat_ms / 1000;
	unsigned int counts;

	wdt_dev->timeout = timeout;

	counts = drvdata->clk_rate * min(timeout, max_hw_heartbeat);
	writel(counts, drvdata->base + WDT_TIMER);

	return 0;
}

static int ls1x_wdt_start(struct watchdog_device *wdt_dev)
{
	struct ls1x_wdt_drvdata *drvdata = watchdog_get_drvdata(wdt_dev);

	writel(0x1, drvdata->base + WDT_EN);

	return 0;
}

static int ls1x_wdt_stop(struct watchdog_device *wdt_dev)
{
	struct ls1x_wdt_drvdata *drvdata = watchdog_get_drvdata(wdt_dev);

	writel(0x0, drvdata->base + WDT_EN);

	return 0;
}

static int ls1x_wdt_restart(struct watchdog_device *wdt_dev,
			    unsigned long action, void *data)
{
	struct ls1x_wdt_drvdata *drvdata = watchdog_get_drvdata(wdt_dev);

	writel(0x1, drvdata->base + WDT_EN);
	writel(0x1, drvdata->base + WDT_TIMER);
	writel(0x1, drvdata->base + WDT_SET);

	return 0;
}

static const struct watchdog_info ls1x_wdt_info = {
	.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
	.identity = "Loongson1 Watchdog",
};

static const struct watchdog_ops ls1x_wdt_ops = {
	.owner = THIS_MODULE,
	.start = ls1x_wdt_start,
	.stop = ls1x_wdt_stop,
	.ping = ls1x_wdt_ping,
	.set_timeout = ls1x_wdt_set_timeout,
	.restart = ls1x_wdt_restart,
};

static int ls1x_wdt_probe(struct platform_device *pdev)
{
	struct device *dev = &pdev->dev;
	struct ls1x_wdt_drvdata *drvdata;
	struct watchdog_device *ls1x_wdt;
	unsigned long clk_rate;
	int err;

	drvdata = devm_kzalloc(dev, sizeof(*drvdata), GFP_KERNEL);
	if (!drvdata)
		return -ENOMEM;

	drvdata->base = devm_platform_ioremap_resource(pdev, 0);
	if (IS_ERR(drvdata->base))
		return PTR_ERR(drvdata->base);

	drvdata->clk = devm_clk_get_enabled(dev, pdev->name);
	if (IS_ERR(drvdata->clk))
		return PTR_ERR(drvdata->clk);

	clk_rate = clk_get_rate(drvdata->clk);
	if (!clk_rate)
		return -EINVAL;
	drvdata->clk_rate = clk_rate;

	ls1x_wdt = &drvdata->wdt;
	ls1x_wdt->info = &ls1x_wdt_info;
	ls1x_wdt->ops = &ls1x_wdt_ops;
	ls1x_wdt->timeout = DEFAULT_HEARTBEAT;
	ls1x_wdt->min_timeout = 1;
	ls1x_wdt->max_hw_heartbeat_ms = U32_MAX / clk_rate * 1000;
	ls1x_wdt->parent = dev;

	watchdog_init_timeout(ls1x_wdt, heartbeat, dev);
	watchdog_set_nowayout(ls1x_wdt, nowayout);
	watchdog_set_drvdata(ls1x_wdt, drvdata);

	err = devm_watchdog_register_device(dev, &drvdata->wdt);
	if (err)
		return err;

	platform_set_drvdata(pdev, drvdata);

	dev_info(dev, "Loongson1 Watchdog driver registered\n");

	return 0;
}

static struct platform_driver ls1x_wdt_driver = {
	.probe = ls1x_wdt_probe,
	.driver = {
		.name = "ls1x-wdt",
	},
};

module_platform_driver(ls1x_wdt_driver);

MODULE_AUTHOR("Yang Ling <gnaygnil@gmail.com>");
MODULE_DESCRIPTION("Loongson1 Watchdog Driver");
MODULE_LICENSE("GPL");
Commit	Line	Data
2874c5fd	1	// SPDX-License-Identifier: GPL-2.0-or-later
1d8565ee YL	2	/*
1d8565ee YL	3	* Copyright (c) 2016 Yang Ling <gnaygnil@gmail.com>
1d8565ee YL	4	*/
	5
	6	#include <linux/clk.h>
	7	#include <linux/module.h>
	8	#include <linux/platform_device.h>
	9	#include <linux/watchdog.h>
2a31bf20 KZ	10
	11	/* Loongson 1 Watchdog Register Definitions */
	12	#define WDT_EN 0x0
	13	#define WDT_TIMER 0x4
	14	#define WDT_SET 0x8
1d8565ee YL	15
	16	#define DEFAULT_HEARTBEAT 30
	17
	18	static bool nowayout = WATCHDOG_NOWAYOUT;
	19	module_param(nowayout, bool, 0444);
	20
	21	static unsigned int heartbeat;
	22	module_param(heartbeat, uint, 0444);
	23
	24	struct ls1x_wdt_drvdata {
	25	void __iomem *base;
	26	struct clk *clk;
	27	unsigned long clk_rate;
	28	struct watchdog_device wdt;
	29	};
	30
	31	static int ls1x_wdt_ping(struct watchdog_device *wdt_dev)
	32	{
	33	struct ls1x_wdt_drvdata *drvdata = watchdog_get_drvdata(wdt_dev);
	34
	35	writel(0x1, drvdata->base + WDT_SET);
	36
	37	return 0;
	38	}
	39
	40	static int ls1x_wdt_set_timeout(struct watchdog_device *wdt_dev,
	41	unsigned int timeout)
	42	{
	43	struct ls1x_wdt_drvdata *drvdata = watchdog_get_drvdata(wdt_dev);
	44	unsigned int max_hw_heartbeat = wdt_dev->max_hw_heartbeat_ms / 1000;
	45	unsigned int counts;
	46
	47	wdt_dev->timeout = timeout;
	48
	49	counts = drvdata->clk_rate * min(timeout, max_hw_heartbeat);
	50	writel(counts, drvdata->base + WDT_TIMER);
	51
	52	return 0;
	53	}
	54
	55	static int ls1x_wdt_start(struct watchdog_device *wdt_dev)
	56	{
	57	struct ls1x_wdt_drvdata *drvdata = watchdog_get_drvdata(wdt_dev);
	58
	59	writel(0x1, drvdata->base + WDT_EN);
	60
	61	return 0;
	62	}
	63
	64	static int ls1x_wdt_stop(struct watchdog_device *wdt_dev)
	65	{
	66	struct ls1x_wdt_drvdata *drvdata = watchdog_get_drvdata(wdt_dev);
	67
	68	writel(0x0, drvdata->base + WDT_EN);
	69
	70	return 0;
	71	}
	72
2a31bf20 KZ	73	static int ls1x_wdt_restart(struct watchdog_device *wdt_dev,
	74	unsigned long action, void *data)
	75	{
	76	struct ls1x_wdt_drvdata *drvdata = watchdog_get_drvdata(wdt_dev);
	77
	78	writel(0x1, drvdata->base + WDT_EN);
	79	writel(0x1, drvdata->base + WDT_TIMER);
	80	writel(0x1, drvdata->base + WDT_SET);
	81
	82	return 0;
	83	}
	84
1d8565ee YL	85	static const struct watchdog_info ls1x_wdt_info = {
	86	.options = WDIOF_SETTIMEOUT \| WDIOF_KEEPALIVEPING \| WDIOF_MAGICCLOSE,
	87	.identity = "Loongson1 Watchdog",
	88	};
	89
	90	static const struct watchdog_ops ls1x_wdt_ops = {
	91	.owner = THIS_MODULE,
	92	.start = ls1x_wdt_start,
	93	.stop = ls1x_wdt_stop,
	94	.ping = ls1x_wdt_ping,
	95	.set_timeout = ls1x_wdt_set_timeout,
2a31bf20	96	.restart = ls1x_wdt_restart,
1d8565ee YL	97	};
	98
	99	static int ls1x_wdt_probe(struct platform_device *pdev)
	100	{
fd56d6c9	101	struct device *dev = &pdev->dev;
1d8565ee YL	102	struct ls1x_wdt_drvdata *drvdata;
	103	struct watchdog_device *ls1x_wdt;
	104	unsigned long clk_rate;
1d8565ee YL	105	int err;
1d8565ee YL	106
fd56d6c9	107	drvdata = devm_kzalloc(dev, sizeof(*drvdata), GFP_KERNEL);
1d8565ee YL	108	if (!drvdata)
	109	return -ENOMEM;
	110
0f0a6a28	111	drvdata->base = devm_platform_ioremap_resource(pdev, 0);
1d8565ee YL	112	if (IS_ERR(drvdata->base))
	113	return PTR_ERR(drvdata->base);
	114
07d41160	115	drvdata->clk = devm_clk_get_enabled(dev, pdev->name);
1d8565ee YL	116	if (IS_ERR(drvdata->clk))
	117	return PTR_ERR(drvdata->clk);
	118
1d8565ee	119	clk_rate = clk_get_rate(drvdata->clk);
fd56d6c9 GR	120	if (!clk_rate)
fd56d6c9 GR	121	return -EINVAL;
1d8565ee YL	122	drvdata->clk_rate = clk_rate;
	123
	124	ls1x_wdt = &drvdata->wdt;
	125	ls1x_wdt->info = &ls1x_wdt_info;
	126	ls1x_wdt->ops = &ls1x_wdt_ops;
	127	ls1x_wdt->timeout = DEFAULT_HEARTBEAT;
	128	ls1x_wdt->min_timeout = 1;
	129	ls1x_wdt->max_hw_heartbeat_ms = U32_MAX / clk_rate * 1000;
fd56d6c9	130	ls1x_wdt->parent = dev;
1d8565ee	131
fd56d6c9	132	watchdog_init_timeout(ls1x_wdt, heartbeat, dev);
1d8565ee YL	133	watchdog_set_nowayout(ls1x_wdt, nowayout);
	134	watchdog_set_drvdata(ls1x_wdt, drvdata);
	135
fd56d6c9	136	err = devm_watchdog_register_device(dev, &drvdata->wdt);
7da54735	137	if (err)
fd56d6c9	138	return err;
1d8565ee YL	139
	140	platform_set_drvdata(pdev, drvdata);
	141
fd56d6c9	142	dev_info(dev, "Loongson1 Watchdog driver registered\n");
1d8565ee YL	143
	144	return 0;
	145	}
	146
	147	static struct platform_driver ls1x_wdt_driver = {
	148	.probe = ls1x_wdt_probe,
1d8565ee YL	149	.driver = {
	150	.name = "ls1x-wdt",
	151	},
	152	};
	153
	154	module_platform_driver(ls1x_wdt_driver);
	155
	156	MODULE_AUTHOR("Yang Ling <gnaygnil@gmail.com>");
	157	MODULE_DESCRIPTION("Loongson1 Watchdog Driver");
	158	MODULE_LICENSE("GPL");