summaryrefslogtreecommitdiffstats
path: root/drivers/watchdog/ftwdt010_wdt.c
blob: a9c2912ee28029192d1be1e8f525dc6adb250b1a (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
/*
 * Watchdog driver for Faraday Technology FTWDT010
 *
 * Copyright (C) 2017 Linus Walleij <linus.walleij@linaro.org>
 *
 * Inspired by the out-of-tree drivers from OpenWRT:
 * Copyright (C) 2009 Paulius Zaleckas <paulius.zaleckas@teltonika.lt>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/bitops.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of_device.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/watchdog.h>

#define FTWDT010_WDCOUNTER	0x0
#define FTWDT010_WDLOAD		0x4
#define FTWDT010_WDRESTART	0x8
#define FTWDT010_WDCR		0xC

#define WDRESTART_MAGIC		0x5AB9

#define WDCR_CLOCK_5MHZ		BIT(4)
#define WDCR_WDEXT		BIT(3)
#define WDCR_WDINTR		BIT(2)
#define WDCR_SYS_RST		BIT(1)
#define WDCR_ENABLE		BIT(0)

#define WDT_CLOCK		5000000		/* 5 MHz */

struct ftwdt010_wdt {
	struct watchdog_device	wdd;
	struct device		*dev;
	void __iomem		*base;
	bool			has_irq;
};

static inline
struct ftwdt010_wdt *to_ftwdt010_wdt(struct watchdog_device *wdd)
{
	return container_of(wdd, struct ftwdt010_wdt, wdd);
}

static int ftwdt010_wdt_start(struct watchdog_device *wdd)
{
	struct ftwdt010_wdt *gwdt = to_ftwdt010_wdt(wdd);
	u32 enable;

	writel(wdd->timeout * WDT_CLOCK, gwdt->base + FTWDT010_WDLOAD);
	writel(WDRESTART_MAGIC, gwdt->base + FTWDT010_WDRESTART);
	/* set clock before enabling */
	enable = WDCR_CLOCK_5MHZ | WDCR_SYS_RST;
	writel(enable, gwdt->base + FTWDT010_WDCR);
	if (gwdt->has_irq)
		enable |= WDCR_WDINTR;
	enable |= WDCR_ENABLE;
	writel(enable, gwdt->base + FTWDT010_WDCR);

	return 0;
}

static int ftwdt010_wdt_stop(struct watchdog_device *wdd)
{
	struct ftwdt010_wdt *gwdt = to_ftwdt010_wdt(wdd);

	writel(0, gwdt->base + FTWDT010_WDCR);

	return 0;
}

static int ftwdt010_wdt_ping(struct watchdog_device *wdd)
{
	struct ftwdt010_wdt *gwdt = to_ftwdt010_wdt(wdd);

	writel(WDRESTART_MAGIC, gwdt->base + FTWDT010_WDRESTART);

	return 0;
}

static int ftwdt010_wdt_set_timeout(struct watchdog_device *wdd,
				  unsigned int timeout)
{
	wdd->timeout = timeout;
	if (watchdog_active(wdd))
		ftwdt010_wdt_start(wdd);

	return 0;
}

static irqreturn_t ftwdt010_wdt_interrupt(int irq, void *data)
{
	struct ftwdt010_wdt *gwdt = data;

	watchdog_notify_pretimeout(&gwdt->wdd);

	return IRQ_HANDLED;
}

static const struct watchdog_ops ftwdt010_wdt_ops = {
	.start		= ftwdt010_wdt_start,
	.stop		= ftwdt010_wdt_stop,
	.ping		= ftwdt010_wdt_ping,
	.set_timeout	= ftwdt010_wdt_set_timeout,
	.owner		= THIS_MODULE,
};

static const struct watchdog_info ftwdt010_wdt_info = {
	.options	= WDIOF_KEEPALIVEPING
			| WDIOF_MAGICCLOSE
			| WDIOF_SETTIMEOUT,
	.identity	= KBUILD_MODNAME,
};


static int ftwdt010_wdt_probe(struct platform_device *pdev)
{
	struct device *dev = &pdev->dev;
	struct resource *res;
	struct ftwdt010_wdt *gwdt;
	unsigned int reg;
	int irq;
	int ret;

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

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	gwdt->base = devm_ioremap_resource(dev, res);
	if (IS_ERR(gwdt->base))
		return PTR_ERR(gwdt->base);

	gwdt->dev = dev;
	gwdt->wdd.info = &ftwdt010_wdt_info;
	gwdt->wdd.ops = &ftwdt010_wdt_ops;
	gwdt->wdd.min_timeout = 1;
	gwdt->wdd.max_timeout = 0xFFFFFFFF / WDT_CLOCK;
	gwdt->wdd.parent = dev;

	/*
	 * If 'timeout-sec' unspecified in devicetree, assume a 13 second
	 * default.
	 */
	gwdt->wdd.timeout = 13U;
	watchdog_init_timeout(&gwdt->wdd, 0, dev);

	reg = readw(gwdt->base + FTWDT010_WDCR);
	if (reg & WDCR_ENABLE) {
		/* Watchdog was enabled by the bootloader, disable it. */
		reg &= ~WDCR_ENABLE;
		writel(reg, gwdt->base + FTWDT010_WDCR);
	}

	irq = platform_get_irq(pdev, 0);
	if (irq) {
		ret = devm_request_irq(dev, irq, ftwdt010_wdt_interrupt, 0,
				       "watchdog bark", gwdt);
		if (ret)
			return ret;
		gwdt->has_irq = true;
	}

	ret = devm_watchdog_register_device(dev, &gwdt->wdd);
	if (ret) {
		dev_err(&pdev->dev, "failed to register watchdog\n");
		return ret;
	}

	/* Set up platform driver data */
	platform_set_drvdata(pdev, gwdt);
	dev_info(dev, "FTWDT010 watchdog driver enabled\n");

	return 0;
}

static int __maybe_unused ftwdt010_wdt_suspend(struct device *dev)
{
	struct ftwdt010_wdt *gwdt = dev_get_drvdata(dev);
	unsigned int reg;

	reg = readw(gwdt->base + FTWDT010_WDCR);
	reg &= ~WDCR_ENABLE;
	writel(reg, gwdt->base + FTWDT010_WDCR);

	return 0;
}

static int __maybe_unused ftwdt010_wdt_resume(struct device *dev)
{
	struct ftwdt010_wdt *gwdt = dev_get_drvdata(dev);
	unsigned int reg;

	if (watchdog_active(&gwdt->wdd)) {
		reg = readw(gwdt->base + FTWDT010_WDCR);
		reg |= WDCR_ENABLE;
		writel(reg, gwdt->base + FTWDT010_WDCR);
	}

	return 0;
}

static const struct dev_pm_ops ftwdt010_wdt_dev_pm_ops = {
	SET_SYSTEM_SLEEP_PM_OPS(ftwdt010_wdt_suspend,
				ftwdt010_wdt_resume)
};

#ifdef CONFIG_OF
static const struct of_device_id ftwdt010_wdt_match[] = {
	{ .compatible = "faraday,ftwdt010" },
	{ .compatible = "cortina,gemini-watchdog" },
	{},
};
MODULE_DEVICE_TABLE(of, ftwdt010_wdt_match);
#endif

static struct platform_driver ftwdt010_wdt_driver = {
	.probe		= ftwdt010_wdt_probe,
	.driver		= {
		.name	= "ftwdt010-wdt",
		.of_match_table = of_match_ptr(ftwdt010_wdt_match),
		.pm = &ftwdt010_wdt_dev_pm_ops,
	},
};
module_platform_driver(ftwdt010_wdt_driver);
MODULE_AUTHOR("Linus Walleij");
MODULE_DESCRIPTION("Watchdog driver for Faraday Technology FTWDT010");
MODULE_LICENSE("GPL");
OpenPOWER on IntegriCloud