summaryrefslogtreecommitdiffstats
path: root/drivers/watchdog/rtd119x_wdt.c
blob: 99caec6882d2f1cef3131df8e3b38dfa8d6c006b (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
/*
 * Realtek RTD129x watchdog
 *
 * Copyright (c) 2017 Andreas Färber
 *
 * SPDX-License-Identifier: GPL-2.0+
 */

#include <linux/bitops.h>
#include <linux/clk.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/platform_device.h>
#include <linux/watchdog.h>

#define RTD119X_TCWCR		0x0
#define RTD119X_TCWTR		0x4
#define RTD119X_TCWOV		0xc

#define RTD119X_TCWCR_WDEN_DISABLED		0xa5
#define RTD119X_TCWCR_WDEN_ENABLED		0xff
#define RTD119X_TCWCR_WDEN_MASK			0xff

#define RTD119X_TCWTR_WDCLR			BIT(0)

struct rtd119x_watchdog_device {
	struct watchdog_device wdt_dev;
	void __iomem *base;
	struct clk *clk;
};

static int rtd119x_wdt_start(struct watchdog_device *wdev)
{
	struct rtd119x_watchdog_device *data = watchdog_get_drvdata(wdev);
	u32 val;

	val = readl_relaxed(data->base + RTD119X_TCWCR);
	val &= ~RTD119X_TCWCR_WDEN_MASK;
	val |= RTD119X_TCWCR_WDEN_ENABLED;
	writel(val, data->base + RTD119X_TCWCR);

	return 0;
}

static int rtd119x_wdt_stop(struct watchdog_device *wdev)
{
	struct rtd119x_watchdog_device *data = watchdog_get_drvdata(wdev);
	u32 val;

	val = readl_relaxed(data->base + RTD119X_TCWCR);
	val &= ~RTD119X_TCWCR_WDEN_MASK;
	val |= RTD119X_TCWCR_WDEN_DISABLED;
	writel(val, data->base + RTD119X_TCWCR);

	return 0;
}

static int rtd119x_wdt_ping(struct watchdog_device *wdev)
{
	struct rtd119x_watchdog_device *data = watchdog_get_drvdata(wdev);

	writel_relaxed(RTD119X_TCWTR_WDCLR, data->base + RTD119X_TCWTR);

	return rtd119x_wdt_start(wdev);
}

static int rtd119x_wdt_set_timeout(struct watchdog_device *wdev, unsigned int val)
{
	struct rtd119x_watchdog_device *data = watchdog_get_drvdata(wdev);

	writel(val * clk_get_rate(data->clk), data->base + RTD119X_TCWOV);

	data->wdt_dev.timeout = val;

	return 0;
}

static const struct watchdog_ops rtd119x_wdt_ops = {
	.owner = THIS_MODULE,
	.start		= rtd119x_wdt_start,
	.stop		= rtd119x_wdt_stop,
	.ping		= rtd119x_wdt_ping,
	.set_timeout	= rtd119x_wdt_set_timeout,
};

static const struct watchdog_info rtd119x_wdt_info = {
	.identity = "rtd119x-wdt",
	.options = 0,
};

static const struct of_device_id rtd119x_wdt_dt_ids[] = {
	 { .compatible = "realtek,rtd1295-watchdog" },
	 { }
};

static int rtd119x_wdt_probe(struct platform_device *pdev)
{
	struct rtd119x_watchdog_device *data;
	struct resource *res;
	int ret;

	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
	if (!data)
		return -ENOMEM;

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

	data->clk = of_clk_get(pdev->dev.of_node, 0);
	if (IS_ERR(data->clk))
		return PTR_ERR(data->clk);

	ret = clk_prepare_enable(data->clk);
	if (ret) {
		clk_put(data->clk);
		return ret;
	}

	data->wdt_dev.info = &rtd119x_wdt_info;
	data->wdt_dev.ops = &rtd119x_wdt_ops;
	data->wdt_dev.timeout = 120;
	data->wdt_dev.max_timeout = 0xffffffff / clk_get_rate(data->clk);
	data->wdt_dev.min_timeout = 1;
	data->wdt_dev.parent = &pdev->dev;

	watchdog_stop_on_reboot(&data->wdt_dev);
	watchdog_set_drvdata(&data->wdt_dev, data);
	platform_set_drvdata(pdev, data);

	writel_relaxed(RTD119X_TCWTR_WDCLR, data->base + RTD119X_TCWTR);
	rtd119x_wdt_set_timeout(&data->wdt_dev, data->wdt_dev.timeout);
	rtd119x_wdt_stop(&data->wdt_dev);

	ret = watchdog_register_device(&data->wdt_dev);
	if (ret) {
		clk_disable_unprepare(data->clk);
		clk_put(data->clk);
		return ret;
	}

	return 0;
}

static int rtd119x_wdt_remove(struct platform_device *pdev)
{
	struct rtd119x_watchdog_device *data = platform_get_drvdata(pdev);

	watchdog_unregister_device(&data->wdt_dev);

	clk_disable_unprepare(data->clk);
	clk_put(data->clk);

	return 0;
}

static struct platform_driver rtd119x_wdt_driver = {
	.probe = rtd119x_wdt_probe,
	.remove = rtd119x_wdt_remove,
	.driver = {
		.name = "rtd1295-watchdog",
		.of_match_table	= rtd119x_wdt_dt_ids,
	},
};
builtin_platform_driver(rtd119x_wdt_driver);