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5
6#include <linux/clk.h>
7#include <linux/module.h>
8#include <linux/platform_device.h>
9#include <linux/watchdog.h>
10#include <loongson1.h>
11
12#define DEFAULT_HEARTBEAT 30
13
14static bool nowayout = WATCHDOG_NOWAYOUT;
15module_param(nowayout, bool, 0444);
16
17static unsigned int heartbeat;
18module_param(heartbeat, uint, 0444);
19
20struct ls1x_wdt_drvdata {
21 void __iomem *base;
22 struct clk *clk;
23 unsigned long clk_rate;
24 struct watchdog_device wdt;
25};
26
27static int ls1x_wdt_ping(struct watchdog_device *wdt_dev)
28{
29 struct ls1x_wdt_drvdata *drvdata = watchdog_get_drvdata(wdt_dev);
30
31 writel(0x1, drvdata->base + WDT_SET);
32
33 return 0;
34}
35
36static int ls1x_wdt_set_timeout(struct watchdog_device *wdt_dev,
37 unsigned int timeout)
38{
39 struct ls1x_wdt_drvdata *drvdata = watchdog_get_drvdata(wdt_dev);
40 unsigned int max_hw_heartbeat = wdt_dev->max_hw_heartbeat_ms / 1000;
41 unsigned int counts;
42
43 wdt_dev->timeout = timeout;
44
45 counts = drvdata->clk_rate * min(timeout, max_hw_heartbeat);
46 writel(counts, drvdata->base + WDT_TIMER);
47
48 return 0;
49}
50
51static int ls1x_wdt_start(struct watchdog_device *wdt_dev)
52{
53 struct ls1x_wdt_drvdata *drvdata = watchdog_get_drvdata(wdt_dev);
54
55 writel(0x1, drvdata->base + WDT_EN);
56
57 return 0;
58}
59
60static int ls1x_wdt_stop(struct watchdog_device *wdt_dev)
61{
62 struct ls1x_wdt_drvdata *drvdata = watchdog_get_drvdata(wdt_dev);
63
64 writel(0x0, drvdata->base + WDT_EN);
65
66 return 0;
67}
68
69static const struct watchdog_info ls1x_wdt_info = {
70 .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
71 .identity = "Loongson1 Watchdog",
72};
73
74static const struct watchdog_ops ls1x_wdt_ops = {
75 .owner = THIS_MODULE,
76 .start = ls1x_wdt_start,
77 .stop = ls1x_wdt_stop,
78 .ping = ls1x_wdt_ping,
79 .set_timeout = ls1x_wdt_set_timeout,
80};
81
82static void ls1x_clk_disable_unprepare(void *data)
83{
84 clk_disable_unprepare(data);
85}
86
87static int ls1x_wdt_probe(struct platform_device *pdev)
88{
89 struct device *dev = &pdev->dev;
90 struct ls1x_wdt_drvdata *drvdata;
91 struct watchdog_device *ls1x_wdt;
92 unsigned long clk_rate;
93 int err;
94
95 drvdata = devm_kzalloc(dev, sizeof(*drvdata), GFP_KERNEL);
96 if (!drvdata)
97 return -ENOMEM;
98
99 drvdata->base = devm_platform_ioremap_resource(pdev, 0);
100 if (IS_ERR(drvdata->base))
101 return PTR_ERR(drvdata->base);
102
103 drvdata->clk = devm_clk_get(dev, pdev->name);
104 if (IS_ERR(drvdata->clk))
105 return PTR_ERR(drvdata->clk);
106
107 err = clk_prepare_enable(drvdata->clk);
108 if (err) {
109 dev_err(dev, "clk enable failed\n");
110 return err;
111 }
112 err = devm_add_action_or_reset(dev, ls1x_clk_disable_unprepare,
113 drvdata->clk);
114 if (err)
115 return err;
116
117 clk_rate = clk_get_rate(drvdata->clk);
118 if (!clk_rate)
119 return -EINVAL;
120 drvdata->clk_rate = clk_rate;
121
122 ls1x_wdt = &drvdata->wdt;
123 ls1x_wdt->info = &ls1x_wdt_info;
124 ls1x_wdt->ops = &ls1x_wdt_ops;
125 ls1x_wdt->timeout = DEFAULT_HEARTBEAT;
126 ls1x_wdt->min_timeout = 1;
127 ls1x_wdt->max_hw_heartbeat_ms = U32_MAX / clk_rate * 1000;
128 ls1x_wdt->parent = dev;
129
130 watchdog_init_timeout(ls1x_wdt, heartbeat, dev);
131 watchdog_set_nowayout(ls1x_wdt, nowayout);
132 watchdog_set_drvdata(ls1x_wdt, drvdata);
133
134 err = devm_watchdog_register_device(dev, &drvdata->wdt);
135 if (err)
136 return err;
137
138 platform_set_drvdata(pdev, drvdata);
139
140 dev_info(dev, "Loongson1 Watchdog driver registered\n");
141
142 return 0;
143}
144
145static struct platform_driver ls1x_wdt_driver = {
146 .probe = ls1x_wdt_probe,
147 .driver = {
148 .name = "ls1x-wdt",
149 },
150};
151
152module_platform_driver(ls1x_wdt_driver);
153
154MODULE_AUTHOR("Yang Ling <gnaygnil@gmail.com>");
155MODULE_DESCRIPTION("Loongson1 Watchdog Driver");
156MODULE_LICENSE("GPL");
157
