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10#include <linux/clk.h>
11#include <linux/module.h>
12#include <linux/platform_device.h>
13#include <linux/watchdog.h>
14#include <loongson1.h>
15
16#define DEFAULT_HEARTBEAT 30
17
18static bool nowayout = WATCHDOG_NOWAYOUT;
19module_param(nowayout, bool, 0444);
20
21static unsigned int heartbeat;
22module_param(heartbeat, uint, 0444);
23
24struct ls1x_wdt_drvdata {
25 void __iomem *base;
26 struct clk *clk;
27 unsigned long clk_rate;
28 struct watchdog_device wdt;
29};
30
31static int ls1x_wdt_ping(struct watchdog_device *wdt_dev)
32{
33 struct ls1x_wdt_drvdata *drvdata = watchdog_get_drvdata(wdt_dev);
34
35 writel(0x1, drvdata->base + WDT_SET);
36
37 return 0;
38}
39
40static int ls1x_wdt_set_timeout(struct watchdog_device *wdt_dev,
41 unsigned int timeout)
42{
43 struct ls1x_wdt_drvdata *drvdata = watchdog_get_drvdata(wdt_dev);
44 unsigned int max_hw_heartbeat = wdt_dev->max_hw_heartbeat_ms / 1000;
45 unsigned int counts;
46
47 wdt_dev->timeout = timeout;
48
49 counts = drvdata->clk_rate * min(timeout, max_hw_heartbeat);
50 writel(counts, drvdata->base + WDT_TIMER);
51
52 return 0;
53}
54
55static int ls1x_wdt_start(struct watchdog_device *wdt_dev)
56{
57 struct ls1x_wdt_drvdata *drvdata = watchdog_get_drvdata(wdt_dev);
58
59 writel(0x1, drvdata->base + WDT_EN);
60
61 return 0;
62}
63
64static int ls1x_wdt_stop(struct watchdog_device *wdt_dev)
65{
66 struct ls1x_wdt_drvdata *drvdata = watchdog_get_drvdata(wdt_dev);
67
68 writel(0x0, drvdata->base + WDT_EN);
69
70 return 0;
71}
72
73static const struct watchdog_info ls1x_wdt_info = {
74 .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
75 .identity = "Loongson1 Watchdog",
76};
77
78static const struct watchdog_ops ls1x_wdt_ops = {
79 .owner = THIS_MODULE,
80 .start = ls1x_wdt_start,
81 .stop = ls1x_wdt_stop,
82 .ping = ls1x_wdt_ping,
83 .set_timeout = ls1x_wdt_set_timeout,
84};
85
86static int ls1x_wdt_probe(struct platform_device *pdev)
87{
88 struct ls1x_wdt_drvdata *drvdata;
89 struct watchdog_device *ls1x_wdt;
90 unsigned long clk_rate;
91 struct resource *res;
92 int err;
93
94 drvdata = devm_kzalloc(&pdev->dev, sizeof(*drvdata), GFP_KERNEL);
95 if (!drvdata)
96 return -ENOMEM;
97
98 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
99 drvdata->base = devm_ioremap_resource(&pdev->dev, res);
100 if (IS_ERR(drvdata->base))
101 return PTR_ERR(drvdata->base);
102
103 drvdata->clk = devm_clk_get(&pdev->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(&pdev->dev, "clk enable failed\n");
110 return err;
111 }
112
113 clk_rate = clk_get_rate(drvdata->clk);
114 if (!clk_rate) {
115 err = -EINVAL;
116 goto err0;
117 }
118 drvdata->clk_rate = clk_rate;
119
120 ls1x_wdt = &drvdata->wdt;
121 ls1x_wdt->info = &ls1x_wdt_info;
122 ls1x_wdt->ops = &ls1x_wdt_ops;
123 ls1x_wdt->timeout = DEFAULT_HEARTBEAT;
124 ls1x_wdt->min_timeout = 1;
125 ls1x_wdt->max_hw_heartbeat_ms = U32_MAX / clk_rate * 1000;
126 ls1x_wdt->parent = &pdev->dev;
127
128 watchdog_init_timeout(ls1x_wdt, heartbeat, &pdev->dev);
129 watchdog_set_nowayout(ls1x_wdt, nowayout);
130 watchdog_set_drvdata(ls1x_wdt, drvdata);
131
132 err = watchdog_register_device(&drvdata->wdt);
133 if (err) {
134 dev_err(&pdev->dev, "failed to register watchdog device\n");
135 goto err0;
136 }
137
138 platform_set_drvdata(pdev, drvdata);
139
140 dev_info(&pdev->dev, "Loongson1 Watchdog driver registered\n");
141
142 return 0;
143err0:
144 clk_disable_unprepare(drvdata->clk);
145 return err;
146}
147
148static int ls1x_wdt_remove(struct platform_device *pdev)
149{
150 struct ls1x_wdt_drvdata *drvdata = platform_get_drvdata(pdev);
151
152 watchdog_unregister_device(&drvdata->wdt);
153 clk_disable_unprepare(drvdata->clk);
154
155 return 0;
156}
157
158static struct platform_driver ls1x_wdt_driver = {
159 .probe = ls1x_wdt_probe,
160 .remove = ls1x_wdt_remove,
161 .driver = {
162 .name = "ls1x-wdt",
163 },
164};
165
166module_platform_driver(ls1x_wdt_driver);
167
168MODULE_AUTHOR("Yang Ling <gnaygnil@gmail.com>");
169MODULE_DESCRIPTION("Loongson1 Watchdog Driver");
170MODULE_LICENSE("GPL");
171
