[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>
#include <loongson1.h>

#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 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,
};

static void ls1x_clk_disable_unprepare(void *data)
{
	clk_disable_unprepare(data);
}

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

	err = clk_prepare_enable(drvdata->clk);
	if (err) {
		dev_err(dev, "clk enable failed\n");
		return err;
	}
	err = devm_add_action_or_reset(dev, ls1x_clk_disable_unprepare,
				       drvdata->clk);
	if (err)
		return err;

	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) {
		dev_err(dev, "failed to register watchdog device\n");
		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>
	10	#include <loongson1.h>
	11
	12	#define DEFAULT_HEARTBEAT 30
	13
	14	static bool nowayout = WATCHDOG_NOWAYOUT;
	15	module_param(nowayout, bool, 0444);
	16
	17	static unsigned int heartbeat;
	18	module_param(heartbeat, uint, 0444);
	19
	20	struct ls1x_wdt_drvdata {
	21	void __iomem *base;
	22	struct clk *clk;
	23	unsigned long clk_rate;
	24	struct watchdog_device wdt;
	25	};
	26
	27	static int ls1x_wdt_ping(struct watchdog_device *wdt_dev)
	28	{
	29	struct ls1x_wdt_drvdata *drvdata = watchdog_get_drvdata(wdt_dev);
	30
	31	writel(0x1, drvdata->base + WDT_SET);
	32
	33	return 0;
	34	}
	35
	36	static int ls1x_wdt_set_timeout(struct watchdog_device *wdt_dev,
	37	unsigned int timeout)
	38	{
	39	struct ls1x_wdt_drvdata *drvdata = watchdog_get_drvdata(wdt_dev);
	40	unsigned int max_hw_heartbeat = wdt_dev->max_hw_heartbeat_ms / 1000;
	41	unsigned int counts;
	42
	43	wdt_dev->timeout = timeout;
	44
	45	counts = drvdata->clk_rate * min(timeout, max_hw_heartbeat);
	46	writel(counts, drvdata->base + WDT_TIMER);
	47
	48	return 0;
	49	}
	50
	51	static int ls1x_wdt_start(struct watchdog_device *wdt_dev)
	52	{
	53	struct ls1x_wdt_drvdata *drvdata = watchdog_get_drvdata(wdt_dev);
	54
	55	writel(0x1, drvdata->base + WDT_EN);
	56
	57	return 0;
	58	}
	59
	60	static int ls1x_wdt_stop(struct watchdog_device *wdt_dev)
	61	{
	62	struct ls1x_wdt_drvdata *drvdata = watchdog_get_drvdata(wdt_dev);
	63
	64	writel(0x0, drvdata->base + WDT_EN);
	65
	66	return 0;
	67	}
68
69	static const struct watchdog_info ls1x_wdt_info = {
70	.options = WDIOF_SETTIMEOUT \| WDIOF_KEEPALIVEPING \| WDIOF_MAGICCLOSE,
71	.identity = "Loongson1 Watchdog",
72	};
73
74	static const struct watchdog_ops ls1x_wdt_ops = {
75	.owner = THIS_MODULE,
76	.start = ls1x_wdt_start,
77	.stop = ls1x_wdt_stop,
78	.ping = ls1x_wdt_ping,
79	.set_timeout = ls1x_wdt_set_timeout,
80	};
81
fd56d6c9 GR	82	static void ls1x_clk_disable_unprepare(void *data)
	83	{
	84	clk_disable_unprepare(data);
	85	}
	86
1d8565ee YL	87	static int ls1x_wdt_probe(struct platform_device *pdev)
1d8565ee YL	88	{
fd56d6c9	89	struct device *dev = &pdev->dev;
1d8565ee YL	90	struct ls1x_wdt_drvdata *drvdata;
	91	struct watchdog_device *ls1x_wdt;
	92	unsigned long clk_rate;
1d8565ee YL	93	int err;
1d8565ee YL	94
fd56d6c9	95	drvdata = devm_kzalloc(dev, sizeof(*drvdata), GFP_KERNEL);
1d8565ee YL	96	if (!drvdata)
	97	return -ENOMEM;
	98
0f0a6a28	99	drvdata->base = devm_platform_ioremap_resource(pdev, 0);
1d8565ee YL	100	if (IS_ERR(drvdata->base))
	101	return PTR_ERR(drvdata->base);
	102
fd56d6c9	103	drvdata->clk = devm_clk_get(dev, pdev->name);
1d8565ee YL	104	if (IS_ERR(drvdata->clk))
	105	return PTR_ERR(drvdata->clk);
	106
	107	err = clk_prepare_enable(drvdata->clk);
	108	if (err) {
fd56d6c9	109	dev_err(dev, "clk enable failed\n");
1d8565ee YL	110	return err;
1d8565ee YL	111	}
fd56d6c9 GR	112	err = devm_add_action_or_reset(dev, ls1x_clk_disable_unprepare,
	113	drvdata->clk);
	114	if (err)
	115	return err;
1d8565ee YL	116
1d8565ee YL	117	clk_rate = clk_get_rate(drvdata->clk);
fd56d6c9 GR	118	if (!clk_rate)
fd56d6c9 GR	119	return -EINVAL;
1d8565ee YL	120	drvdata->clk_rate = clk_rate;
	121
	122	ls1x_wdt = &drvdata->wdt;
	123	ls1x_wdt->info = &ls1x_wdt_info;
	124	ls1x_wdt->ops = &ls1x_wdt_ops;
	125	ls1x_wdt->timeout = DEFAULT_HEARTBEAT;
	126	ls1x_wdt->min_timeout = 1;
	127	ls1x_wdt->max_hw_heartbeat_ms = U32_MAX / clk_rate * 1000;
fd56d6c9	128	ls1x_wdt->parent = dev;
1d8565ee	129
fd56d6c9	130	watchdog_init_timeout(ls1x_wdt, heartbeat, dev);
1d8565ee YL	131	watchdog_set_nowayout(ls1x_wdt, nowayout);
	132	watchdog_set_drvdata(ls1x_wdt, drvdata);
	133
fd56d6c9	134	err = devm_watchdog_register_device(dev, &drvdata->wdt);
1d8565ee	135	if (err) {
fd56d6c9 GR	136	dev_err(dev, "failed to register watchdog device\n");
fd56d6c9 GR	137	return err;
1d8565ee YL	138	}
	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");