blob: 2789da2c05156d02931779cd21322a24e5f133e2 [file] [log] [blame]
Jonas Jensene14538e2013-08-02 16:40:45 +02001/*
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/err.h>
17#include <linux/kernel.h>
Guenter Roeckad0e0e62014-09-26 00:03:17 +000018#include <linux/notifier.h>
Jonas Jensene14538e2013-08-02 16:40:45 +020019#include <linux/platform_device.h>
Guenter Roeckad0e0e62014-09-26 00:03:17 +000020#include <linux/reboot.h>
Jonas Jensene14538e2013-08-02 16:40:45 +020021#include <linux/watchdog.h>
22#include <linux/moduleparam.h>
23
24#define REG_COUNT 0x4
25#define REG_MODE 0x8
26#define REG_ENABLE 0xC
27
28struct moxart_wdt_dev {
29 struct watchdog_device dev;
30 void __iomem *base;
31 unsigned int clock_frequency;
Guenter Roeckad0e0e62014-09-26 00:03:17 +000032 struct notifier_block restart_handler;
Jonas Jensene14538e2013-08-02 16:40:45 +020033};
34
35static int heartbeat;
36
Guenter Roeckad0e0e62014-09-26 00:03:17 +000037static int moxart_restart_handle(struct notifier_block *this,
38 unsigned long mode, void *cmd)
Jonas Jensen87739262013-12-18 16:18:03 +010039{
Guenter Roeckad0e0e62014-09-26 00:03:17 +000040 struct moxart_wdt_dev *moxart_wdt = container_of(this,
41 struct moxart_wdt_dev,
42 restart_handler);
43 writel(1, moxart_wdt->base + REG_COUNT);
44 writel(0x5ab9, moxart_wdt->base + REG_MODE);
45 writel(0x03, moxart_wdt->base + REG_ENABLE);
46
47 return NOTIFY_DONE;
Jonas Jensen87739262013-12-18 16:18:03 +010048}
49
Jonas Jensene14538e2013-08-02 16:40:45 +020050static int moxart_wdt_stop(struct watchdog_device *wdt_dev)
51{
52 struct moxart_wdt_dev *moxart_wdt = watchdog_get_drvdata(wdt_dev);
53
54 writel(0, moxart_wdt->base + REG_ENABLE);
55
56 return 0;
57}
58
59static int moxart_wdt_start(struct watchdog_device *wdt_dev)
60{
61 struct moxart_wdt_dev *moxart_wdt = watchdog_get_drvdata(wdt_dev);
62
63 writel(moxart_wdt->clock_frequency * wdt_dev->timeout,
64 moxart_wdt->base + REG_COUNT);
65 writel(0x5ab9, moxart_wdt->base + REG_MODE);
66 writel(0x03, moxart_wdt->base + REG_ENABLE);
67
68 return 0;
69}
70
71static int moxart_wdt_set_timeout(struct watchdog_device *wdt_dev,
72 unsigned int timeout)
73{
74 wdt_dev->timeout = timeout;
75
76 return 0;
77}
78
79static const struct watchdog_info moxart_wdt_info = {
80 .identity = "moxart-wdt",
81 .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING |
82 WDIOF_MAGICCLOSE,
83};
84
85static const struct watchdog_ops moxart_wdt_ops = {
86 .owner = THIS_MODULE,
87 .start = moxart_wdt_start,
88 .stop = moxart_wdt_stop,
89 .set_timeout = moxart_wdt_set_timeout,
90};
91
92static int moxart_wdt_probe(struct platform_device *pdev)
93{
94 struct moxart_wdt_dev *moxart_wdt;
95 struct device *dev = &pdev->dev;
96 struct device_node *node = dev->of_node;
97 struct resource *res;
98 struct clk *clk;
99 int err;
100 unsigned int max_timeout;
101 bool nowayout = WATCHDOG_NOWAYOUT;
102
103 moxart_wdt = devm_kzalloc(dev, sizeof(*moxart_wdt), GFP_KERNEL);
104 if (!moxart_wdt)
105 return -ENOMEM;
106
107 platform_set_drvdata(pdev, moxart_wdt);
108
109 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
110 moxart_wdt->base = devm_ioremap_resource(dev, res);
111 if (IS_ERR(moxart_wdt->base))
112 return PTR_ERR(moxart_wdt->base);
113
114 clk = of_clk_get(node, 0);
115 if (IS_ERR(clk)) {
116 pr_err("%s: of_clk_get failed\n", __func__);
117 return PTR_ERR(clk);
118 }
119
120 moxart_wdt->clock_frequency = clk_get_rate(clk);
121 if (moxart_wdt->clock_frequency == 0) {
122 pr_err("%s: incorrect clock frequency\n", __func__);
123 return -EINVAL;
124 }
125
126 max_timeout = UINT_MAX / moxart_wdt->clock_frequency;
127
128 moxart_wdt->dev.info = &moxart_wdt_info;
129 moxart_wdt->dev.ops = &moxart_wdt_ops;
130 moxart_wdt->dev.timeout = max_timeout;
131 moxart_wdt->dev.min_timeout = 1;
132 moxart_wdt->dev.max_timeout = max_timeout;
133 moxart_wdt->dev.parent = dev;
134
135 watchdog_init_timeout(&moxart_wdt->dev, heartbeat, dev);
136 watchdog_set_nowayout(&moxart_wdt->dev, nowayout);
137
138 watchdog_set_drvdata(&moxart_wdt->dev, moxart_wdt);
139
140 err = watchdog_register_device(&moxart_wdt->dev);
141 if (err)
142 return err;
143
Guenter Roeckad0e0e62014-09-26 00:03:17 +0000144 moxart_wdt->restart_handler.notifier_call = moxart_restart_handle;
145 moxart_wdt->restart_handler.priority = 128;
146 err = register_restart_handler(&moxart_wdt->restart_handler);
147 if (err)
148 dev_err(dev, "cannot register restart notifier (err=%d)\n",
149 err);
Jonas Jensen87739262013-12-18 16:18:03 +0100150
Jonas Jensene14538e2013-08-02 16:40:45 +0200151 dev_dbg(dev, "Watchdog enabled (heartbeat=%d sec, nowayout=%d)\n",
152 moxart_wdt->dev.timeout, nowayout);
153
154 return 0;
155}
156
157static int moxart_wdt_remove(struct platform_device *pdev)
158{
159 struct moxart_wdt_dev *moxart_wdt = platform_get_drvdata(pdev);
160
Guenter Roeckad0e0e62014-09-26 00:03:17 +0000161 unregister_restart_handler(&moxart_wdt->restart_handler);
Jonas Jensene14538e2013-08-02 16:40:45 +0200162 moxart_wdt_stop(&moxart_wdt->dev);
Jonas Jensene14538e2013-08-02 16:40:45 +0200163
164 return 0;
165}
166
167static const struct of_device_id moxart_watchdog_match[] = {
168 { .compatible = "moxa,moxart-watchdog" },
169 { },
170};
171
172static struct platform_driver moxart_wdt_driver = {
173 .probe = moxart_wdt_probe,
174 .remove = moxart_wdt_remove,
175 .driver = {
176 .name = "moxart-watchdog",
Jonas Jensene14538e2013-08-02 16:40:45 +0200177 .of_match_table = moxart_watchdog_match,
178 },
179};
180module_platform_driver(moxart_wdt_driver);
181
182module_param(heartbeat, int, 0);
183MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat in seconds");
184
185MODULE_DESCRIPTION("MOXART watchdog driver");
186MODULE_LICENSE("GPL");
187MODULE_AUTHOR("Jonas Jensen <jonas.jensen@gmail.com>");