Gitiles
Code Review Sign In
192.168.1.100 / T800 / 2f45a6900d5d100dd4c723c7ff44bf5a8471665d / . / src / kernel / linux / v4.19 / drivers / watchdog / moxart_wdt.c
blob: 430c3ab84c07c49b509c937dc5d9c2c2486ab8a4 [file] [log] [blame]
xjb04a4022021-11-25 15:01:52 +0800[diff] [blame]1/*
2 * MOXA ART SoCs watchdog driver.
3 *
4 * Copyright (C) 2013 Jonas Jensen
5 *
6 * Jonas Jensen <jonas.jensen@gmail.com>
7 *
8 * This file is licensed under the terms of the GNU General Public
9 * License version 2. This program is licensed "as is" without any
10 * warranty of any kind, whether express or implied.
11 */
12
13#include <linux/clk.h>
14#include <linux/io.h>
15#include <linux/module.h>
16#include <linux/mod_devicetable.h>
17#include <linux/err.h>
18#include <linux/kernel.h>
19#include <linux/platform_device.h>
20#include <linux/watchdog.h>
21#include <linux/moduleparam.h>
22
23#define REG_COUNT 0x4
24#define REG_MODE 0x8
25#define REG_ENABLE 0xC
26
27struct moxart_wdt_dev {
28 struct watchdog_device dev;
29 void __iomem *base;
30 unsigned int clock_frequency;
31};
32
33static int heartbeat;
34
35static int moxart_wdt_restart(struct watchdog_device *wdt_dev,
36 unsigned long action, void *data)
37{
38 struct moxart_wdt_dev *moxart_wdt = watchdog_get_drvdata(wdt_dev);
39
40 writel(1, moxart_wdt->base + REG_COUNT);
41 writel(0x5ab9, moxart_wdt->base + REG_MODE);
42 writel(0x03, moxart_wdt->base + REG_ENABLE);
43
44 return 0;
45}
46
47static int moxart_wdt_stop(struct watchdog_device *wdt_dev)
48{
49 struct moxart_wdt_dev *moxart_wdt = watchdog_get_drvdata(wdt_dev);
50
51 writel(0, moxart_wdt->base + REG_ENABLE);
52
53 return 0;
54}
55
56static int moxart_wdt_start(struct watchdog_device *wdt_dev)
57{
58 struct moxart_wdt_dev *moxart_wdt = watchdog_get_drvdata(wdt_dev);
59
60 writel(moxart_wdt->clock_frequency * wdt_dev->timeout,
61 moxart_wdt->base + REG_COUNT);
62 writel(0x5ab9, moxart_wdt->base + REG_MODE);
63 writel(0x03, moxart_wdt->base + REG_ENABLE);
64
65 return 0;
66}
67
68static int moxart_wdt_set_timeout(struct watchdog_device *wdt_dev,
69 unsigned int timeout)
70{
71 wdt_dev->timeout = timeout;
72
73 return 0;
74}
75
76static const struct watchdog_info moxart_wdt_info = {
77 .identity = "moxart-wdt",
78 .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING |
79 WDIOF_MAGICCLOSE,
80};
81
82static const struct watchdog_ops moxart_wdt_ops = {
83 .owner = THIS_MODULE,
84 .start = moxart_wdt_start,
85 .stop = moxart_wdt_stop,
86 .set_timeout = moxart_wdt_set_timeout,
87 .restart = moxart_wdt_restart,
88};
89
90static int moxart_wdt_probe(struct platform_device *pdev)
91{
92 struct moxart_wdt_dev *moxart_wdt;
93 struct device *dev = &pdev->dev;
94 struct device_node *node = dev->of_node;
95 struct resource *res;
96 struct clk *clk;
97 int err;
98 unsigned int max_timeout;
99 bool nowayout = WATCHDOG_NOWAYOUT;
100
101 moxart_wdt = devm_kzalloc(dev, sizeof(*moxart_wdt), GFP_KERNEL);
102 if (!moxart_wdt)
103 return -ENOMEM;
104
105 platform_set_drvdata(pdev, moxart_wdt);
106
107 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
108 moxart_wdt->base = devm_ioremap_resource(dev, res);
109 if (IS_ERR(moxart_wdt->base))
110 return PTR_ERR(moxart_wdt->base);
111
112 clk = of_clk_get(node, 0);
113 if (IS_ERR(clk)) {
114 pr_err("%s: of_clk_get failed\n", __func__);
115 return PTR_ERR(clk);
116 }
117
118 moxart_wdt->clock_frequency = clk_get_rate(clk);
119 if (moxart_wdt->clock_frequency == 0) {
120 pr_err("%s: incorrect clock frequency\n", __func__);
121 return -EINVAL;
122 }
123
124 max_timeout = UINT_MAX / moxart_wdt->clock_frequency;
125
126 moxart_wdt->dev.info = &moxart_wdt_info;
127 moxart_wdt->dev.ops = &moxart_wdt_ops;
128 moxart_wdt->dev.timeout = max_timeout;
129 moxart_wdt->dev.min_timeout = 1;
130 moxart_wdt->dev.max_timeout = max_timeout;
131 moxart_wdt->dev.parent = dev;
132
133 watchdog_init_timeout(&moxart_wdt->dev, heartbeat, dev);
134 watchdog_set_nowayout(&moxart_wdt->dev, nowayout);
135 watchdog_set_restart_priority(&moxart_wdt->dev, 128);
136
137 watchdog_set_drvdata(&moxart_wdt->dev, moxart_wdt);
138
139 err = watchdog_register_device(&moxart_wdt->dev);
140 if (err)
141 return err;
142
143 dev_dbg(dev, "Watchdog enabled (heartbeat=%d sec, nowayout=%d)\n",
144 moxart_wdt->dev.timeout, nowayout);
145
146 return 0;
147}
148
149static int moxart_wdt_remove(struct platform_device *pdev)
150{
151 struct moxart_wdt_dev *moxart_wdt = platform_get_drvdata(pdev);
152
153 moxart_wdt_stop(&moxart_wdt->dev);
154
155 return 0;
156}
157
158static const struct of_device_id moxart_watchdog_match[] = {
159 { .compatible = "moxa,moxart-watchdog" },
160 { },
161};
162MODULE_DEVICE_TABLE(of, moxart_watchdog_match);
163
164static struct platform_driver moxart_wdt_driver = {
165 .probe = moxart_wdt_probe,
166 .remove = moxart_wdt_remove,
167 .driver = {
168 .name = "moxart-watchdog",
169 .of_match_table = moxart_watchdog_match,
170 },
171};
172module_platform_driver(moxart_wdt_driver);
173
174module_param(heartbeat, int, 0);
175MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat in seconds");
176
177MODULE_DESCRIPTION("MOXART watchdog driver");
178MODULE_LICENSE("GPL");
179MODULE_AUTHOR("Jonas Jensen <jonas.jensen@gmail.com>");