This source file includes following definitions.
- tangox_wdt_set_timeout
- tangox_wdt_start
- tangox_wdt_stop
- tangox_wdt_get_timeleft
- tangox_wdt_restart
- tangox_clk_disable_unprepare
- tangox_wdt_probe
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7 #include <linux/bitops.h>
8 #include <linux/clk.h>
9 #include <linux/delay.h>
10 #include <linux/io.h>
11 #include <linux/kernel.h>
12 #include <linux/module.h>
13 #include <linux/moduleparam.h>
14 #include <linux/mod_devicetable.h>
15 #include <linux/platform_device.h>
16 #include <linux/watchdog.h>
17
18 #define DEFAULT_TIMEOUT 30
19
20 static bool nowayout = WATCHDOG_NOWAYOUT;
21 module_param(nowayout, bool, 0);
22 MODULE_PARM_DESC(nowayout,
23 "Watchdog cannot be stopped once started (default="
24 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
25
26 static unsigned int timeout;
27 module_param(timeout, int, 0);
28 MODULE_PARM_DESC(timeout, "Watchdog timeout");
29
30
31
32
33
34 #define WD_COUNTER 0
35
36 #define WD_CONFIG 4
37 #define WD_CONFIG_XTAL_IN BIT(0)
38 #define WD_CONFIG_DISABLE BIT(31)
39
40 struct tangox_wdt_device {
41 struct watchdog_device wdt;
42 void __iomem *base;
43 unsigned long clk_rate;
44 struct clk *clk;
45 };
46
47 static int tangox_wdt_set_timeout(struct watchdog_device *wdt,
48 unsigned int new_timeout)
49 {
50 wdt->timeout = new_timeout;
51
52 return 0;
53 }
54
55 static int tangox_wdt_start(struct watchdog_device *wdt)
56 {
57 struct tangox_wdt_device *dev = watchdog_get_drvdata(wdt);
58 u32 ticks;
59
60 ticks = 1 + wdt->timeout * dev->clk_rate;
61 writel(ticks, dev->base + WD_COUNTER);
62
63 return 0;
64 }
65
66 static int tangox_wdt_stop(struct watchdog_device *wdt)
67 {
68 struct tangox_wdt_device *dev = watchdog_get_drvdata(wdt);
69
70 writel(0, dev->base + WD_COUNTER);
71
72 return 0;
73 }
74
75 static unsigned int tangox_wdt_get_timeleft(struct watchdog_device *wdt)
76 {
77 struct tangox_wdt_device *dev = watchdog_get_drvdata(wdt);
78 u32 count;
79
80 count = readl(dev->base + WD_COUNTER);
81
82 if (!count)
83 return 0;
84
85 return (count - 1) / dev->clk_rate;
86 }
87
88 static const struct watchdog_info tangox_wdt_info = {
89 .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
90 .identity = "tangox watchdog",
91 };
92
93 static int tangox_wdt_restart(struct watchdog_device *wdt,
94 unsigned long action, void *data)
95 {
96 struct tangox_wdt_device *dev = watchdog_get_drvdata(wdt);
97
98 writel(1, dev->base + WD_COUNTER);
99
100 return 0;
101 }
102
103 static const struct watchdog_ops tangox_wdt_ops = {
104 .start = tangox_wdt_start,
105 .stop = tangox_wdt_stop,
106 .set_timeout = tangox_wdt_set_timeout,
107 .get_timeleft = tangox_wdt_get_timeleft,
108 .restart = tangox_wdt_restart,
109 };
110
111 static void tangox_clk_disable_unprepare(void *data)
112 {
113 clk_disable_unprepare(data);
114 }
115
116 static int tangox_wdt_probe(struct platform_device *pdev)
117 {
118 struct tangox_wdt_device *dev;
119 u32 config;
120 int err;
121
122 dev = devm_kzalloc(&pdev->dev, sizeof(*dev), GFP_KERNEL);
123 if (!dev)
124 return -ENOMEM;
125
126 dev->base = devm_platform_ioremap_resource(pdev, 0);
127 if (IS_ERR(dev->base))
128 return PTR_ERR(dev->base);
129
130 dev->clk = devm_clk_get(&pdev->dev, NULL);
131 if (IS_ERR(dev->clk))
132 return PTR_ERR(dev->clk);
133
134 err = clk_prepare_enable(dev->clk);
135 if (err)
136 return err;
137 err = devm_add_action_or_reset(&pdev->dev,
138 tangox_clk_disable_unprepare, dev->clk);
139 if (err)
140 return err;
141
142 dev->clk_rate = clk_get_rate(dev->clk);
143 if (!dev->clk_rate)
144 return -EINVAL;
145
146 dev->wdt.parent = &pdev->dev;
147 dev->wdt.info = &tangox_wdt_info;
148 dev->wdt.ops = &tangox_wdt_ops;
149 dev->wdt.timeout = DEFAULT_TIMEOUT;
150 dev->wdt.min_timeout = 1;
151 dev->wdt.max_hw_heartbeat_ms = (U32_MAX - 1) / dev->clk_rate;
152
153 watchdog_init_timeout(&dev->wdt, timeout, &pdev->dev);
154 watchdog_set_nowayout(&dev->wdt, nowayout);
155 watchdog_set_drvdata(&dev->wdt, dev);
156
157
158
159
160
161 config = readl(dev->base + WD_CONFIG);
162 if (config & WD_CONFIG_DISABLE)
163 writel(0, dev->base + WD_COUNTER);
164
165 writel(WD_CONFIG_XTAL_IN, dev->base + WD_CONFIG);
166
167
168
169
170
171 if (readl(dev->base + WD_COUNTER)) {
172 set_bit(WDOG_HW_RUNNING, &dev->wdt.status);
173 tangox_wdt_start(&dev->wdt);
174 }
175
176 watchdog_set_restart_priority(&dev->wdt, 128);
177
178 watchdog_stop_on_unregister(&dev->wdt);
179 err = devm_watchdog_register_device(&pdev->dev, &dev->wdt);
180 if (err)
181 return err;
182
183 platform_set_drvdata(pdev, dev);
184
185 dev_info(&pdev->dev, "SMP86xx/SMP87xx watchdog registered\n");
186
187 return 0;
188 }
189
190 static const struct of_device_id tangox_wdt_dt_ids[] = {
191 { .compatible = "sigma,smp8642-wdt" },
192 { .compatible = "sigma,smp8759-wdt" },
193 { }
194 };
195 MODULE_DEVICE_TABLE(of, tangox_wdt_dt_ids);
196
197 static struct platform_driver tangox_wdt_driver = {
198 .probe = tangox_wdt_probe,
199 .driver = {
200 .name = "tangox-wdt",
201 .of_match_table = tangox_wdt_dt_ids,
202 },
203 };
204
205 module_platform_driver(tangox_wdt_driver);
206
207 MODULE_AUTHOR("Mans Rullgard <mans@mansr.com>");
208 MODULE_DESCRIPTION("SMP86xx/SMP87xx Watchdog driver");
209 MODULE_LICENSE("GPL");