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e14538e0 JJ |
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/err.h> | |
17 | #include <linux/kernel.h> | |
18 | #include <linux/platform_device.h> | |
19 | #include <linux/watchdog.h> | |
20 | #include <linux/moduleparam.h> | |
21 | ||
22 | #define REG_COUNT 0x4 | |
23 | #define REG_MODE 0x8 | |
24 | #define REG_ENABLE 0xC | |
25 | ||
26 | struct moxart_wdt_dev { | |
27 | struct watchdog_device dev; | |
28 | void __iomem *base; | |
29 | unsigned int clock_frequency; | |
30 | }; | |
31 | ||
32 | static int heartbeat; | |
33 | ||
4d8b229d GR |
34 | static int moxart_wdt_restart(struct watchdog_device *wdt_dev, |
35 | unsigned long action, void *data) | |
8773926d | 36 | { |
46c17f0f DR |
37 | struct moxart_wdt_dev *moxart_wdt = watchdog_get_drvdata(wdt_dev); |
38 | ||
ad0e0e68 GR |
39 | writel(1, moxart_wdt->base + REG_COUNT); |
40 | writel(0x5ab9, moxart_wdt->base + REG_MODE); | |
41 | writel(0x03, moxart_wdt->base + REG_ENABLE); | |
42 | ||
46c17f0f | 43 | return 0; |
8773926d JJ |
44 | } |
45 | ||
e14538e0 JJ |
46 | static int moxart_wdt_stop(struct watchdog_device *wdt_dev) |
47 | { | |
48 | struct moxart_wdt_dev *moxart_wdt = watchdog_get_drvdata(wdt_dev); | |
49 | ||
50 | writel(0, moxart_wdt->base + REG_ENABLE); | |
51 | ||
52 | return 0; | |
53 | } | |
54 | ||
55 | static int moxart_wdt_start(struct watchdog_device *wdt_dev) | |
56 | { | |
57 | struct moxart_wdt_dev *moxart_wdt = watchdog_get_drvdata(wdt_dev); | |
58 | ||
59 | writel(moxart_wdt->clock_frequency * wdt_dev->timeout, | |
60 | moxart_wdt->base + REG_COUNT); | |
61 | writel(0x5ab9, moxart_wdt->base + REG_MODE); | |
62 | writel(0x03, moxart_wdt->base + REG_ENABLE); | |
63 | ||
64 | return 0; | |
65 | } | |
66 | ||
67 | static int moxart_wdt_set_timeout(struct watchdog_device *wdt_dev, | |
68 | unsigned int timeout) | |
69 | { | |
70 | wdt_dev->timeout = timeout; | |
71 | ||
72 | return 0; | |
73 | } | |
74 | ||
75 | static const struct watchdog_info moxart_wdt_info = { | |
76 | .identity = "moxart-wdt", | |
77 | .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | | |
78 | WDIOF_MAGICCLOSE, | |
79 | }; | |
80 | ||
81 | static const struct watchdog_ops moxart_wdt_ops = { | |
82 | .owner = THIS_MODULE, | |
83 | .start = moxart_wdt_start, | |
84 | .stop = moxart_wdt_stop, | |
85 | .set_timeout = moxart_wdt_set_timeout, | |
46c17f0f | 86 | .restart = moxart_wdt_restart, |
e14538e0 JJ |
87 | }; |
88 | ||
89 | static int moxart_wdt_probe(struct platform_device *pdev) | |
90 | { | |
91 | struct moxart_wdt_dev *moxart_wdt; | |
92 | struct device *dev = &pdev->dev; | |
93 | struct device_node *node = dev->of_node; | |
94 | struct resource *res; | |
95 | struct clk *clk; | |
96 | int err; | |
97 | unsigned int max_timeout; | |
98 | bool nowayout = WATCHDOG_NOWAYOUT; | |
99 | ||
100 | moxart_wdt = devm_kzalloc(dev, sizeof(*moxart_wdt), GFP_KERNEL); | |
101 | if (!moxart_wdt) | |
102 | return -ENOMEM; | |
103 | ||
104 | platform_set_drvdata(pdev, moxart_wdt); | |
105 | ||
106 | res = platform_get_resource(pdev, IORESOURCE_MEM, 0); | |
107 | moxart_wdt->base = devm_ioremap_resource(dev, res); | |
108 | if (IS_ERR(moxart_wdt->base)) | |
109 | return PTR_ERR(moxart_wdt->base); | |
110 | ||
111 | clk = of_clk_get(node, 0); | |
112 | if (IS_ERR(clk)) { | |
113 | pr_err("%s: of_clk_get failed\n", __func__); | |
114 | return PTR_ERR(clk); | |
115 | } | |
116 | ||
117 | moxart_wdt->clock_frequency = clk_get_rate(clk); | |
118 | if (moxart_wdt->clock_frequency == 0) { | |
119 | pr_err("%s: incorrect clock frequency\n", __func__); | |
120 | return -EINVAL; | |
121 | } | |
122 | ||
123 | max_timeout = UINT_MAX / moxart_wdt->clock_frequency; | |
124 | ||
125 | moxart_wdt->dev.info = &moxart_wdt_info; | |
126 | moxart_wdt->dev.ops = &moxart_wdt_ops; | |
127 | moxart_wdt->dev.timeout = max_timeout; | |
128 | moxart_wdt->dev.min_timeout = 1; | |
129 | moxart_wdt->dev.max_timeout = max_timeout; | |
130 | moxart_wdt->dev.parent = dev; | |
131 | ||
132 | watchdog_init_timeout(&moxart_wdt->dev, heartbeat, dev); | |
133 | watchdog_set_nowayout(&moxart_wdt->dev, nowayout); | |
46c17f0f | 134 | watchdog_set_restart_priority(&moxart_wdt->dev, 128); |
e14538e0 JJ |
135 | |
136 | watchdog_set_drvdata(&moxart_wdt->dev, moxart_wdt); | |
137 | ||
138 | err = watchdog_register_device(&moxart_wdt->dev); | |
139 | if (err) | |
140 | return err; | |
141 | ||
142 | dev_dbg(dev, "Watchdog enabled (heartbeat=%d sec, nowayout=%d)\n", | |
143 | moxart_wdt->dev.timeout, nowayout); | |
144 | ||
145 | return 0; | |
146 | } | |
147 | ||
148 | static int moxart_wdt_remove(struct platform_device *pdev) | |
149 | { | |
150 | struct moxart_wdt_dev *moxart_wdt = platform_get_drvdata(pdev); | |
151 | ||
152 | moxart_wdt_stop(&moxart_wdt->dev); | |
e14538e0 JJ |
153 | |
154 | return 0; | |
155 | } | |
156 | ||
157 | static const struct of_device_id moxart_watchdog_match[] = { | |
158 | { .compatible = "moxa,moxart-watchdog" }, | |
159 | { }, | |
160 | }; | |
c73318f4 | 161 | MODULE_DEVICE_TABLE(of, moxart_watchdog_match); |
e14538e0 JJ |
162 | |
163 | static struct platform_driver moxart_wdt_driver = { | |
164 | .probe = moxart_wdt_probe, | |
165 | .remove = moxart_wdt_remove, | |
166 | .driver = { | |
167 | .name = "moxart-watchdog", | |
e14538e0 JJ |
168 | .of_match_table = moxart_watchdog_match, |
169 | }, | |
170 | }; | |
171 | module_platform_driver(moxart_wdt_driver); | |
172 | ||
173 | module_param(heartbeat, int, 0); | |
174 | MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat in seconds"); | |
175 | ||
176 | MODULE_DESCRIPTION("MOXART watchdog driver"); | |
177 | MODULE_LICENSE("GPL"); | |
178 | MODULE_AUTHOR("Jonas Jensen <jonas.jensen@gmail.com>"); |