[linux-2.6-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/io.h>
#include <linux/module.h>
#include <linux/of.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, NULL);
	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;
}

#ifdef CONFIG_OF
static const struct of_device_id ls1x_wdt_dt_ids[] = {
	{ .compatible = "loongson,ls1b-wdt", },
	{ .compatible = "loongson,ls1c-wdt", },
	{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, ls1x_wdt_dt_ids);
#endif

static struct platform_driver ls1x_wdt_driver = {
	.probe = ls1x_wdt_probe,
	.driver = {
		.name = "ls1x-wdt",
		.of_match_table = of_match_ptr(ls1x_wdt_dt_ids),
	},
};

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>
f1a43aad	7	#include <linux/io.h>
1d8565ee	8	#include <linux/module.h>
20fbe629	9	#include <linux/of.h>
1d8565ee YL	10	#include <linux/platform_device.h>
1d8565ee YL	11	#include <linux/watchdog.h>
2a31bf20 KZ	12
	13	/* Loongson 1 Watchdog Register Definitions */
	14	#define WDT_EN 0x0
	15	#define WDT_TIMER 0x4
	16	#define WDT_SET 0x8
1d8565ee YL	17
	18	#define DEFAULT_HEARTBEAT 30
	19
	20	static bool nowayout = WATCHDOG_NOWAYOUT;
	21	module_param(nowayout, bool, 0444);
	22
	23	static unsigned int heartbeat;
	24	module_param(heartbeat, uint, 0444);
	25
	26	struct ls1x_wdt_drvdata {
	27	void __iomem *base;
	28	struct clk *clk;
	29	unsigned long clk_rate;
	30	struct watchdog_device wdt;
	31	};
	32
	33	static int ls1x_wdt_ping(struct watchdog_device *wdt_dev)
	34	{
	35	struct ls1x_wdt_drvdata *drvdata = watchdog_get_drvdata(wdt_dev);
	36
	37	writel(0x1, drvdata->base + WDT_SET);
	38
	39	return 0;
	40	}
	41
	42	static int ls1x_wdt_set_timeout(struct watchdog_device *wdt_dev,
	43	unsigned int timeout)
	44	{
	45	struct ls1x_wdt_drvdata *drvdata = watchdog_get_drvdata(wdt_dev);
	46	unsigned int max_hw_heartbeat = wdt_dev->max_hw_heartbeat_ms / 1000;
	47	unsigned int counts;
	48
	49	wdt_dev->timeout = timeout;
	50
	51	counts = drvdata->clk_rate * min(timeout, max_hw_heartbeat);
	52	writel(counts, drvdata->base + WDT_TIMER);
	53
	54	return 0;
	55	}
	56
	57	static int ls1x_wdt_start(struct watchdog_device *wdt_dev)
	58	{
	59	struct ls1x_wdt_drvdata *drvdata = watchdog_get_drvdata(wdt_dev);
	60
	61	writel(0x1, drvdata->base + WDT_EN);
	62
	63	return 0;
	64	}
	65
	66	static int ls1x_wdt_stop(struct watchdog_device *wdt_dev)
	67	{
	68	struct ls1x_wdt_drvdata *drvdata = watchdog_get_drvdata(wdt_dev);
	69
	70	writel(0x0, drvdata->base + WDT_EN);
	71
	72	return 0;
	73	}
	74
2a31bf20 KZ	75	static int ls1x_wdt_restart(struct watchdog_device *wdt_dev,
	76	unsigned long action, void *data)
	77	{
	78	struct ls1x_wdt_drvdata *drvdata = watchdog_get_drvdata(wdt_dev);
	79
	80	writel(0x1, drvdata->base + WDT_EN);
	81	writel(0x1, drvdata->base + WDT_TIMER);
	82	writel(0x1, drvdata->base + WDT_SET);
	83
	84	return 0;
	85	}
	86
1d8565ee YL	87	static const struct watchdog_info ls1x_wdt_info = {
	88	.options = WDIOF_SETTIMEOUT \| WDIOF_KEEPALIVEPING \| WDIOF_MAGICCLOSE,
	89	.identity = "Loongson1 Watchdog",
	90	};
	91
	92	static const struct watchdog_ops ls1x_wdt_ops = {
	93	.owner = THIS_MODULE,
	94	.start = ls1x_wdt_start,
	95	.stop = ls1x_wdt_stop,
	96	.ping = ls1x_wdt_ping,
	97	.set_timeout = ls1x_wdt_set_timeout,
2a31bf20	98	.restart = ls1x_wdt_restart,
1d8565ee YL	99	};
	100
	101	static int ls1x_wdt_probe(struct platform_device *pdev)
	102	{
fd56d6c9	103	struct device *dev = &pdev->dev;
1d8565ee YL	104	struct ls1x_wdt_drvdata *drvdata;
	105	struct watchdog_device *ls1x_wdt;
	106	unsigned long clk_rate;
1d8565ee YL	107	int err;
1d8565ee YL	108
fd56d6c9	109	drvdata = devm_kzalloc(dev, sizeof(*drvdata), GFP_KERNEL);
1d8565ee YL	110	if (!drvdata)
	111	return -ENOMEM;
	112
0f0a6a28	113	drvdata->base = devm_platform_ioremap_resource(pdev, 0);
1d8565ee YL	114	if (IS_ERR(drvdata->base))
	115	return PTR_ERR(drvdata->base);
	116
20fbe629	117	drvdata->clk = devm_clk_get_enabled(dev, NULL);
1d8565ee YL	118	if (IS_ERR(drvdata->clk))
	119	return PTR_ERR(drvdata->clk);
	120
1d8565ee	121	clk_rate = clk_get_rate(drvdata->clk);
fd56d6c9 GR	122	if (!clk_rate)
fd56d6c9 GR	123	return -EINVAL;
1d8565ee YL	124	drvdata->clk_rate = clk_rate;
	125
	126	ls1x_wdt = &drvdata->wdt;
	127	ls1x_wdt->info = &ls1x_wdt_info;
	128	ls1x_wdt->ops = &ls1x_wdt_ops;
	129	ls1x_wdt->timeout = DEFAULT_HEARTBEAT;
	130	ls1x_wdt->min_timeout = 1;
	131	ls1x_wdt->max_hw_heartbeat_ms = U32_MAX / clk_rate * 1000;
fd56d6c9	132	ls1x_wdt->parent = dev;
1d8565ee	133
fd56d6c9	134	watchdog_init_timeout(ls1x_wdt, heartbeat, dev);
1d8565ee YL	135	watchdog_set_nowayout(ls1x_wdt, nowayout);
	136	watchdog_set_drvdata(ls1x_wdt, drvdata);
	137
fd56d6c9	138	err = devm_watchdog_register_device(dev, &drvdata->wdt);
7da54735	139	if (err)
fd56d6c9	140	return err;
1d8565ee YL	141
	142	platform_set_drvdata(pdev, drvdata);
	143
fd56d6c9	144	dev_info(dev, "Loongson1 Watchdog driver registered\n");
1d8565ee YL	145
	146	return 0;
	147	}
	148
20fbe629 KZ	149	#ifdef CONFIG_OF
	150	static const struct of_device_id ls1x_wdt_dt_ids[] = {
	151	{ .compatible = "loongson,ls1b-wdt", },
	152	{ .compatible = "loongson,ls1c-wdt", },
	153	{ /* sentinel */ }
	154	};
	155	MODULE_DEVICE_TABLE(of, ls1x_wdt_dt_ids);
	156	#endif
	157
1d8565ee YL	158	static struct platform_driver ls1x_wdt_driver = {
1d8565ee YL	159	.probe = ls1x_wdt_probe,
1d8565ee YL	160	.driver = {
1d8565ee YL	161	.name = "ls1x-wdt",
20fbe629	162	.of_match_table = of_match_ptr(ls1x_wdt_dt_ids),
1d8565ee YL	163	},
	164	};
	165
	166	module_platform_driver(ls1x_wdt_driver);
	167
	168	MODULE_AUTHOR("Yang Ling <gnaygnil@gmail.com>");
	169	MODULE_DESCRIPTION("Loongson1 Watchdog Driver");
	170	MODULE_LICENSE("GPL");