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10#include <linux/bitops.h>
11#include <linux/mfd/syscon.h>
12#include <linux/module.h>
13#include <linux/of.h>
14#include <linux/platform_device.h>
15#include <linux/regmap.h>
16#include <linux/watchdog.h>
17
18
19#define WDTTIMSET 0x3004
20#define WDTTIMSET_PERIOD_MASK (0xf << 0)
21#define WDTTIMSET_PERIOD_1_SEC (0x3 << 0)
22
23
24#define WDTRSTSEL 0x3008
25#define WDTRSTSEL_RSTSEL_MASK (0x3 << 0)
26#define WDTRSTSEL_RSTSEL_BOTH (0x0 << 0)
27#define WDTRSTSEL_RSTSEL_IRQ_ONLY (0x2 << 0)
28
29
30#define WDTCTRL 0x300c
31#define WDTCTRL_STATUS BIT(8)
32#define WDTCTRL_CLEAR BIT(1)
33#define WDTCTRL_ENABLE BIT(0)
34
35#define SEC_TO_WDTTIMSET_PRD(sec) \
36 (ilog2(sec) + WDTTIMSET_PERIOD_1_SEC)
37
38#define WDTST_TIMEOUT 1000
39
40#define WDT_DEFAULT_TIMEOUT 64
41#define WDT_PERIOD_MIN 1
42#define WDT_PERIOD_MAX 128
43
44static unsigned int timeout = 0;
45static bool nowayout = WATCHDOG_NOWAYOUT;
46
47struct uniphier_wdt_dev {
48 struct watchdog_device wdt_dev;
49 struct regmap *regmap;
50};
51
52
53
54
55static int uniphier_watchdog_ping(struct watchdog_device *w)
56{
57 struct uniphier_wdt_dev *wdev = watchdog_get_drvdata(w);
58 unsigned int val;
59 int ret;
60
61
62 ret = regmap_write_bits(wdev->regmap, WDTCTRL,
63 WDTCTRL_CLEAR, WDTCTRL_CLEAR);
64 if (!ret)
65
66
67
68
69 ret = regmap_read_poll_timeout(wdev->regmap, WDTCTRL, val,
70 (val & WDTCTRL_STATUS),
71 0, WDTST_TIMEOUT);
72
73 return ret;
74}
75
76static int __uniphier_watchdog_start(struct regmap *regmap, unsigned int sec)
77{
78 unsigned int val;
79 int ret;
80
81 ret = regmap_read_poll_timeout(regmap, WDTCTRL, val,
82 !(val & WDTCTRL_STATUS),
83 0, WDTST_TIMEOUT);
84 if (ret)
85 return ret;
86
87
88 ret = regmap_write(regmap, WDTTIMSET,
89 SEC_TO_WDTTIMSET_PRD(sec));
90 if (ret)
91 return ret;
92
93
94 ret = regmap_write(regmap, WDTCTRL, WDTCTRL_ENABLE | WDTCTRL_CLEAR);
95 if (!ret)
96
97
98
99
100 ret = regmap_read_poll_timeout(regmap, WDTCTRL, val,
101 (val & WDTCTRL_STATUS),
102 0, WDTST_TIMEOUT);
103
104 return ret;
105}
106
107static int __uniphier_watchdog_stop(struct regmap *regmap)
108{
109
110 return regmap_write_bits(regmap, WDTCTRL, WDTCTRL_ENABLE, 0);
111}
112
113static int __uniphier_watchdog_restart(struct regmap *regmap, unsigned int sec)
114{
115 int ret;
116
117 ret = __uniphier_watchdog_stop(regmap);
118 if (ret)
119 return ret;
120
121 return __uniphier_watchdog_start(regmap, sec);
122}
123
124static int uniphier_watchdog_start(struct watchdog_device *w)
125{
126 struct uniphier_wdt_dev *wdev = watchdog_get_drvdata(w);
127 unsigned int tmp_timeout;
128
129 tmp_timeout = roundup_pow_of_two(w->timeout);
130
131 return __uniphier_watchdog_start(wdev->regmap, tmp_timeout);
132}
133
134static int uniphier_watchdog_stop(struct watchdog_device *w)
135{
136 struct uniphier_wdt_dev *wdev = watchdog_get_drvdata(w);
137
138 return __uniphier_watchdog_stop(wdev->regmap);
139}
140
141static int uniphier_watchdog_set_timeout(struct watchdog_device *w,
142 unsigned int t)
143{
144 struct uniphier_wdt_dev *wdev = watchdog_get_drvdata(w);
145 unsigned int tmp_timeout;
146 int ret;
147
148 tmp_timeout = roundup_pow_of_two(t);
149 if (tmp_timeout == w->timeout)
150 return 0;
151
152 if (watchdog_active(w)) {
153 ret = __uniphier_watchdog_restart(wdev->regmap, tmp_timeout);
154 if (ret)
155 return ret;
156 }
157
158 w->timeout = tmp_timeout;
159
160 return 0;
161}
162
163
164
165
166static const struct watchdog_info uniphier_wdt_info = {
167 .identity = "uniphier-wdt",
168 .options = WDIOF_SETTIMEOUT |
169 WDIOF_KEEPALIVEPING |
170 WDIOF_MAGICCLOSE |
171 WDIOF_OVERHEAT,
172};
173
174static const struct watchdog_ops uniphier_wdt_ops = {
175 .owner = THIS_MODULE,
176 .start = uniphier_watchdog_start,
177 .stop = uniphier_watchdog_stop,
178 .ping = uniphier_watchdog_ping,
179 .set_timeout = uniphier_watchdog_set_timeout,
180};
181
182static int uniphier_wdt_probe(struct platform_device *pdev)
183{
184 struct device *dev = &pdev->dev;
185 struct uniphier_wdt_dev *wdev;
186 struct regmap *regmap;
187 struct device_node *parent;
188 int ret;
189
190 wdev = devm_kzalloc(dev, sizeof(*wdev), GFP_KERNEL);
191 if (!wdev)
192 return -ENOMEM;
193
194 parent = of_get_parent(dev->of_node);
195 regmap = syscon_node_to_regmap(parent);
196 of_node_put(parent);
197 if (IS_ERR(regmap))
198 return PTR_ERR(regmap);
199
200 wdev->regmap = regmap;
201 wdev->wdt_dev.info = &uniphier_wdt_info;
202 wdev->wdt_dev.ops = &uniphier_wdt_ops;
203 wdev->wdt_dev.max_timeout = WDT_PERIOD_MAX;
204 wdev->wdt_dev.min_timeout = WDT_PERIOD_MIN;
205 wdev->wdt_dev.timeout = WDT_DEFAULT_TIMEOUT;
206 wdev->wdt_dev.parent = dev;
207
208 watchdog_init_timeout(&wdev->wdt_dev, timeout, dev);
209 watchdog_set_nowayout(&wdev->wdt_dev, nowayout);
210 watchdog_stop_on_reboot(&wdev->wdt_dev);
211
212 watchdog_set_drvdata(&wdev->wdt_dev, wdev);
213
214 uniphier_watchdog_stop(&wdev->wdt_dev);
215 ret = regmap_write(wdev->regmap, WDTRSTSEL, WDTRSTSEL_RSTSEL_BOTH);
216 if (ret)
217 return ret;
218
219 ret = devm_watchdog_register_device(dev, &wdev->wdt_dev);
220 if (ret)
221 return ret;
222
223 dev_info(dev, "watchdog driver (timeout=%d sec, nowayout=%d)\n",
224 wdev->wdt_dev.timeout, nowayout);
225
226 return 0;
227}
228
229static const struct of_device_id uniphier_wdt_dt_ids[] = {
230 { .compatible = "socionext,uniphier-wdt" },
231 { }
232};
233MODULE_DEVICE_TABLE(of, uniphier_wdt_dt_ids);
234
235static struct platform_driver uniphier_wdt_driver = {
236 .probe = uniphier_wdt_probe,
237 .driver = {
238 .name = "uniphier-wdt",
239 .of_match_table = uniphier_wdt_dt_ids,
240 },
241};
242
243module_platform_driver(uniphier_wdt_driver);
244
245module_param(timeout, uint, 0000);
246MODULE_PARM_DESC(timeout,
247 "Watchdog timeout seconds in power of 2. (0 < timeout < 128, default="
248 __MODULE_STRING(WDT_DEFAULT_TIMEOUT) ")");
249
250module_param(nowayout, bool, 0000);
251MODULE_PARM_DESC(nowayout,
252 "Watchdog cannot be stopped once started (default="
253 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
254
255MODULE_AUTHOR("Keiji Hayashibara <hayashibara.keiji@socionext.com>");
256MODULE_DESCRIPTION("UniPhier Watchdog Device Driver");
257MODULE_LICENSE("GPL v2");
258
