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12#include <linux/clk.h>
13#include <linux/delay.h>
14#include <linux/err.h>
15#include <linux/init.h>
16#include <linux/io.h>
17#include <linux/kernel.h>
18#include <linux/module.h>
19#include <linux/moduleparam.h>
20#include <linux/of.h>
21#include <linux/of_device.h>
22#include <linux/platform_device.h>
23#include <linux/types.h>
24#include <linux/watchdog.h>
25
26#define WDT_MAX_TIMEOUT 16
27#define WDT_MIN_TIMEOUT 1
28#define WDT_TIMEOUT_MASK 0x0F
29
30#define WDT_CTRL_RELOAD ((1 << 0) | (0x0a57 << 1))
31
32#define WDT_MODE_EN (1 << 0)
33
34#define DRV_NAME "sunxi-wdt"
35#define DRV_VERSION "1.0"
36
37static bool nowayout = WATCHDOG_NOWAYOUT;
38static unsigned int timeout;
39
40
41
42
43
44struct sunxi_wdt_reg {
45 u8 wdt_ctrl;
46 u8 wdt_cfg;
47 u8 wdt_mode;
48 u8 wdt_timeout_shift;
49 u8 wdt_reset_mask;
50 u8 wdt_reset_val;
51};
52
53struct sunxi_wdt_dev {
54 struct watchdog_device wdt_dev;
55 void __iomem *wdt_base;
56 const struct sunxi_wdt_reg *wdt_regs;
57};
58
59
60
61
62
63
64
65
66
67static const int wdt_timeout_map[] = {
68 [1] = 0x1,
69 [2] = 0x2,
70 [3] = 0x3,
71 [4] = 0x4,
72 [5] = 0x5,
73 [6] = 0x6,
74 [8] = 0x7,
75 [10] = 0x8,
76 [12] = 0x9,
77 [14] = 0xA,
78 [16] = 0xB,
79};
80
81
82static int sunxi_wdt_restart(struct watchdog_device *wdt_dev,
83 unsigned long action, void *data)
84{
85 struct sunxi_wdt_dev *sunxi_wdt = watchdog_get_drvdata(wdt_dev);
86 void __iomem *wdt_base = sunxi_wdt->wdt_base;
87 const struct sunxi_wdt_reg *regs = sunxi_wdt->wdt_regs;
88 u32 val;
89
90
91 val = readl(wdt_base + regs->wdt_cfg);
92 val &= ~(regs->wdt_reset_mask);
93 val |= regs->wdt_reset_val;
94 writel(val, wdt_base + regs->wdt_cfg);
95
96
97 val = readl(wdt_base + regs->wdt_mode);
98 val &= ~(WDT_TIMEOUT_MASK << regs->wdt_timeout_shift);
99 val |= WDT_MODE_EN;
100 writel(val, wdt_base + regs->wdt_mode);
101
102
103
104
105
106 writel(WDT_CTRL_RELOAD, wdt_base + regs->wdt_ctrl);
107
108 while (1) {
109 mdelay(5);
110 val = readl(wdt_base + regs->wdt_mode);
111 val |= WDT_MODE_EN;
112 writel(val, wdt_base + regs->wdt_mode);
113 }
114 return 0;
115}
116
117static int sunxi_wdt_ping(struct watchdog_device *wdt_dev)
118{
119 struct sunxi_wdt_dev *sunxi_wdt = watchdog_get_drvdata(wdt_dev);
120 void __iomem *wdt_base = sunxi_wdt->wdt_base;
121 const struct sunxi_wdt_reg *regs = sunxi_wdt->wdt_regs;
122
123 writel(WDT_CTRL_RELOAD, wdt_base + regs->wdt_ctrl);
124
125 return 0;
126}
127
128static int sunxi_wdt_set_timeout(struct watchdog_device *wdt_dev,
129 unsigned int timeout)
130{
131 struct sunxi_wdt_dev *sunxi_wdt = watchdog_get_drvdata(wdt_dev);
132 void __iomem *wdt_base = sunxi_wdt->wdt_base;
133 const struct sunxi_wdt_reg *regs = sunxi_wdt->wdt_regs;
134 u32 reg;
135
136 if (wdt_timeout_map[timeout] == 0)
137 timeout++;
138
139 sunxi_wdt->wdt_dev.timeout = timeout;
140
141 reg = readl(wdt_base + regs->wdt_mode);
142 reg &= ~(WDT_TIMEOUT_MASK << regs->wdt_timeout_shift);
143 reg |= wdt_timeout_map[timeout] << regs->wdt_timeout_shift;
144 writel(reg, wdt_base + regs->wdt_mode);
145
146 sunxi_wdt_ping(wdt_dev);
147
148 return 0;
149}
150
151static int sunxi_wdt_stop(struct watchdog_device *wdt_dev)
152{
153 struct sunxi_wdt_dev *sunxi_wdt = watchdog_get_drvdata(wdt_dev);
154 void __iomem *wdt_base = sunxi_wdt->wdt_base;
155 const struct sunxi_wdt_reg *regs = sunxi_wdt->wdt_regs;
156
157 writel(0, wdt_base + regs->wdt_mode);
158
159 return 0;
160}
161
162static int sunxi_wdt_start(struct watchdog_device *wdt_dev)
163{
164 u32 reg;
165 struct sunxi_wdt_dev *sunxi_wdt = watchdog_get_drvdata(wdt_dev);
166 void __iomem *wdt_base = sunxi_wdt->wdt_base;
167 const struct sunxi_wdt_reg *regs = sunxi_wdt->wdt_regs;
168 int ret;
169
170 ret = sunxi_wdt_set_timeout(&sunxi_wdt->wdt_dev,
171 sunxi_wdt->wdt_dev.timeout);
172 if (ret < 0)
173 return ret;
174
175
176 reg = readl(wdt_base + regs->wdt_cfg);
177 reg &= ~(regs->wdt_reset_mask);
178 reg |= regs->wdt_reset_val;
179 writel(reg, wdt_base + regs->wdt_cfg);
180
181
182 reg = readl(wdt_base + regs->wdt_mode);
183 reg |= WDT_MODE_EN;
184 writel(reg, wdt_base + regs->wdt_mode);
185
186 return 0;
187}
188
189static const struct watchdog_info sunxi_wdt_info = {
190 .identity = DRV_NAME,
191 .options = WDIOF_SETTIMEOUT |
192 WDIOF_KEEPALIVEPING |
193 WDIOF_MAGICCLOSE,
194};
195
196static const struct watchdog_ops sunxi_wdt_ops = {
197 .owner = THIS_MODULE,
198 .start = sunxi_wdt_start,
199 .stop = sunxi_wdt_stop,
200 .ping = sunxi_wdt_ping,
201 .set_timeout = sunxi_wdt_set_timeout,
202 .restart = sunxi_wdt_restart,
203};
204
205static const struct sunxi_wdt_reg sun4i_wdt_reg = {
206 .wdt_ctrl = 0x00,
207 .wdt_cfg = 0x04,
208 .wdt_mode = 0x04,
209 .wdt_timeout_shift = 3,
210 .wdt_reset_mask = 0x02,
211 .wdt_reset_val = 0x02,
212};
213
214static const struct sunxi_wdt_reg sun6i_wdt_reg = {
215 .wdt_ctrl = 0x10,
216 .wdt_cfg = 0x14,
217 .wdt_mode = 0x18,
218 .wdt_timeout_shift = 4,
219 .wdt_reset_mask = 0x03,
220 .wdt_reset_val = 0x01,
221};
222
223static const struct of_device_id sunxi_wdt_dt_ids[] = {
224 { .compatible = "allwinner,sun4i-a10-wdt", .data = &sun4i_wdt_reg },
225 { .compatible = "allwinner,sun6i-a31-wdt", .data = &sun6i_wdt_reg },
226 { }
227};
228MODULE_DEVICE_TABLE(of, sunxi_wdt_dt_ids);
229
230static int sunxi_wdt_probe(struct platform_device *pdev)
231{
232 struct device *dev = &pdev->dev;
233 struct sunxi_wdt_dev *sunxi_wdt;
234 int err;
235
236 sunxi_wdt = devm_kzalloc(dev, sizeof(*sunxi_wdt), GFP_KERNEL);
237 if (!sunxi_wdt)
238 return -ENOMEM;
239
240 sunxi_wdt->wdt_regs = of_device_get_match_data(dev);
241 if (!sunxi_wdt->wdt_regs)
242 return -ENODEV;
243
244 sunxi_wdt->wdt_base = devm_platform_ioremap_resource(pdev, 0);
245 if (IS_ERR(sunxi_wdt->wdt_base))
246 return PTR_ERR(sunxi_wdt->wdt_base);
247
248 sunxi_wdt->wdt_dev.info = &sunxi_wdt_info;
249 sunxi_wdt->wdt_dev.ops = &sunxi_wdt_ops;
250 sunxi_wdt->wdt_dev.timeout = WDT_MAX_TIMEOUT;
251 sunxi_wdt->wdt_dev.max_timeout = WDT_MAX_TIMEOUT;
252 sunxi_wdt->wdt_dev.min_timeout = WDT_MIN_TIMEOUT;
253 sunxi_wdt->wdt_dev.parent = dev;
254
255 watchdog_init_timeout(&sunxi_wdt->wdt_dev, timeout, dev);
256 watchdog_set_nowayout(&sunxi_wdt->wdt_dev, nowayout);
257 watchdog_set_restart_priority(&sunxi_wdt->wdt_dev, 128);
258
259 watchdog_set_drvdata(&sunxi_wdt->wdt_dev, sunxi_wdt);
260
261 sunxi_wdt_stop(&sunxi_wdt->wdt_dev);
262
263 watchdog_stop_on_reboot(&sunxi_wdt->wdt_dev);
264 err = devm_watchdog_register_device(dev, &sunxi_wdt->wdt_dev);
265 if (unlikely(err))
266 return err;
267
268 dev_info(dev, "Watchdog enabled (timeout=%d sec, nowayout=%d)",
269 sunxi_wdt->wdt_dev.timeout, nowayout);
270
271 return 0;
272}
273
274static struct platform_driver sunxi_wdt_driver = {
275 .probe = sunxi_wdt_probe,
276 .driver = {
277 .name = DRV_NAME,
278 .of_match_table = sunxi_wdt_dt_ids,
279 },
280};
281
282module_platform_driver(sunxi_wdt_driver);
283
284module_param(timeout, uint, 0);
285MODULE_PARM_DESC(timeout, "Watchdog heartbeat in seconds");
286
287module_param(nowayout, bool, 0);
288MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started "
289 "(default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
290
291MODULE_LICENSE("GPL");
292MODULE_AUTHOR("Carlo Caione <carlo.caione@gmail.com>");
293MODULE_AUTHOR("Henrik Nordstrom <henrik@henriknordstrom.net>");
294MODULE_DESCRIPTION("sunxi WatchDog Timer Driver");
295MODULE_VERSION(DRV_VERSION);
296
