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8#include <linux/clk.h>
9#include <linux/io.h>
10#include <linux/module.h>
11#include <linux/moduleparam.h>
12#include <linux/of.h>
13#include <linux/platform_device.h>
14#include <linux/watchdog.h>
15
16#define ATLAS7_TIMER_WDT_INDEX 5
17#define ATLAS7_WDT_DEFAULT_TIMEOUT 20
18
19#define ATLAS7_WDT_CNT_CTRL (0 + 4 * ATLAS7_TIMER_WDT_INDEX)
20#define ATLAS7_WDT_CNT_MATCH (0x18 + 4 * ATLAS7_TIMER_WDT_INDEX)
21#define ATLAS7_WDT_CNT (0x48 + 4 * ATLAS7_TIMER_WDT_INDEX)
22#define ATLAS7_WDT_CNT_EN (BIT(0) | BIT(1))
23#define ATLAS7_WDT_EN 0x64
24
25static unsigned int timeout = ATLAS7_WDT_DEFAULT_TIMEOUT;
26static bool nowayout = WATCHDOG_NOWAYOUT;
27
28module_param(timeout, uint, 0);
29module_param(nowayout, bool, 0);
30
31MODULE_PARM_DESC(timeout, "Default watchdog timeout (in seconds)");
32MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
33 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
34
35struct atlas7_wdog {
36 struct device *dev;
37 void __iomem *base;
38 unsigned long tick_rate;
39 struct clk *clk;
40};
41
42static unsigned int atlas7_wdt_gettimeleft(struct watchdog_device *wdd)
43{
44 struct atlas7_wdog *wdt = watchdog_get_drvdata(wdd);
45 u32 counter, match, delta;
46
47 counter = readl(wdt->base + ATLAS7_WDT_CNT);
48 match = readl(wdt->base + ATLAS7_WDT_CNT_MATCH);
49 delta = match - counter;
50
51 return delta / wdt->tick_rate;
52}
53
54static int atlas7_wdt_ping(struct watchdog_device *wdd)
55{
56 struct atlas7_wdog *wdt = watchdog_get_drvdata(wdd);
57 u32 counter, match, delta;
58
59 counter = readl(wdt->base + ATLAS7_WDT_CNT);
60 delta = wdd->timeout * wdt->tick_rate;
61 match = counter + delta;
62
63 writel(match, wdt->base + ATLAS7_WDT_CNT_MATCH);
64
65 return 0;
66}
67
68static int atlas7_wdt_enable(struct watchdog_device *wdd)
69{
70 struct atlas7_wdog *wdt = watchdog_get_drvdata(wdd);
71
72 atlas7_wdt_ping(wdd);
73
74 writel(readl(wdt->base + ATLAS7_WDT_CNT_CTRL) | ATLAS7_WDT_CNT_EN,
75 wdt->base + ATLAS7_WDT_CNT_CTRL);
76 writel(1, wdt->base + ATLAS7_WDT_EN);
77
78 return 0;
79}
80
81static int atlas7_wdt_disable(struct watchdog_device *wdd)
82{
83 struct atlas7_wdog *wdt = watchdog_get_drvdata(wdd);
84
85 writel(0, wdt->base + ATLAS7_WDT_EN);
86 writel(readl(wdt->base + ATLAS7_WDT_CNT_CTRL) & ~ATLAS7_WDT_CNT_EN,
87 wdt->base + ATLAS7_WDT_CNT_CTRL);
88
89 return 0;
90}
91
92static int atlas7_wdt_settimeout(struct watchdog_device *wdd, unsigned int to)
93{
94 wdd->timeout = to;
95
96 return 0;
97}
98
99#define OPTIONS (WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE)
100
101static const struct watchdog_info atlas7_wdt_ident = {
102 .options = OPTIONS,
103 .firmware_version = 0,
104 .identity = "atlas7 Watchdog",
105};
106
107static const struct watchdog_ops atlas7_wdt_ops = {
108 .owner = THIS_MODULE,
109 .start = atlas7_wdt_enable,
110 .stop = atlas7_wdt_disable,
111 .get_timeleft = atlas7_wdt_gettimeleft,
112 .ping = atlas7_wdt_ping,
113 .set_timeout = atlas7_wdt_settimeout,
114};
115
116static struct watchdog_device atlas7_wdd = {
117 .info = &atlas7_wdt_ident,
118 .ops = &atlas7_wdt_ops,
119 .timeout = ATLAS7_WDT_DEFAULT_TIMEOUT,
120};
121
122static const struct of_device_id atlas7_wdt_ids[] = {
123 { .compatible = "sirf,atlas7-tick"},
124 {}
125};
126
127static void atlas7_clk_disable_unprepare(void *data)
128{
129 clk_disable_unprepare(data);
130}
131
132static int atlas7_wdt_probe(struct platform_device *pdev)
133{
134 struct device *dev = &pdev->dev;
135 struct atlas7_wdog *wdt;
136 struct clk *clk;
137 int ret;
138
139 wdt = devm_kzalloc(dev, sizeof(*wdt), GFP_KERNEL);
140 if (!wdt)
141 return -ENOMEM;
142 wdt->base = devm_platform_ioremap_resource(pdev, 0);
143 if (IS_ERR(wdt->base))
144 return PTR_ERR(wdt->base);
145
146 clk = devm_clk_get(dev, NULL);
147 if (IS_ERR(clk))
148 return PTR_ERR(clk);
149 ret = clk_prepare_enable(clk);
150 if (ret) {
151 dev_err(dev, "clk enable failed\n");
152 return ret;
153 }
154 ret = devm_add_action_or_reset(dev, atlas7_clk_disable_unprepare, clk);
155 if (ret)
156 return ret;
157
158
159 writel(0, wdt->base + ATLAS7_WDT_CNT_CTRL);
160
161 wdt->tick_rate = clk_get_rate(clk);
162 if (!wdt->tick_rate)
163 return -EINVAL;
164
165 wdt->clk = clk;
166 atlas7_wdd.min_timeout = 1;
167 atlas7_wdd.max_timeout = UINT_MAX / wdt->tick_rate;
168
169 watchdog_init_timeout(&atlas7_wdd, 0, dev);
170 watchdog_set_nowayout(&atlas7_wdd, nowayout);
171
172 watchdog_set_drvdata(&atlas7_wdd, wdt);
173 platform_set_drvdata(pdev, &atlas7_wdd);
174
175 watchdog_stop_on_reboot(&atlas7_wdd);
176 watchdog_stop_on_unregister(&atlas7_wdd);
177 return devm_watchdog_register_device(dev, &atlas7_wdd);
178}
179
180static int __maybe_unused atlas7_wdt_suspend(struct device *dev)
181{
182
183
184
185
186 return 0;
187}
188
189static int __maybe_unused atlas7_wdt_resume(struct device *dev)
190{
191 struct watchdog_device *wdd = dev_get_drvdata(dev);
192
193
194
195
196
197
198 atlas7_wdt_ping(wdd);
199
200 return 0;
201}
202
203static SIMPLE_DEV_PM_OPS(atlas7_wdt_pm_ops,
204 atlas7_wdt_suspend, atlas7_wdt_resume);
205
206MODULE_DEVICE_TABLE(of, atlas7_wdt_ids);
207
208static struct platform_driver atlas7_wdt_driver = {
209 .driver = {
210 .name = "atlas7-wdt",
211 .pm = &atlas7_wdt_pm_ops,
212 .of_match_table = atlas7_wdt_ids,
213 },
214 .probe = atlas7_wdt_probe,
215};
216module_platform_driver(atlas7_wdt_driver);
217
218MODULE_DESCRIPTION("CSRatlas7 watchdog driver");
219MODULE_AUTHOR("Guo Zeng <Guo.Zeng@csr.com>");
220MODULE_LICENSE("GPL v2");
221MODULE_ALIAS("platform:atlas7-wdt");
222
