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16#include <linux/clk.h>
17#include <linux/delay.h>
18#include <linux/err.h>
19#include <linux/init.h>
20#include <linux/io.h>
21#include <linux/kernel.h>
22#include <linux/module.h>
23#include <linux/moduleparam.h>
24#include <linux/of.h>
25#include <linux/of_device.h>
26#include <linux/platform_device.h>
27#include <linux/types.h>
28#include <linux/watchdog.h>
29
30#define WDT_MAX_TIMEOUT 16
31#define WDT_MIN_TIMEOUT 1
32#define WDT_TIMEOUT_MASK 0x0F
33
34#define WDT_CTRL_RELOAD ((1 << 0) | (0x0a57 << 1))
35
36#define WDT_MODE_EN (1 << 0)
37
38#define DRV_NAME "sunxi-wdt"
39#define DRV_VERSION "1.0"
40
41static bool nowayout = WATCHDOG_NOWAYOUT;
42static unsigned int timeout = WDT_MAX_TIMEOUT;
43
44
45
46
47
48struct sunxi_wdt_reg {
49 u8 wdt_ctrl;
50 u8 wdt_cfg;
51 u8 wdt_mode;
52 u8 wdt_timeout_shift;
53 u8 wdt_reset_mask;
54 u8 wdt_reset_val;
55};
56
57struct sunxi_wdt_dev {
58 struct watchdog_device wdt_dev;
59 void __iomem *wdt_base;
60 const struct sunxi_wdt_reg *wdt_regs;
61};
62
63
64
65
66
67
68
69
70
71static const int wdt_timeout_map[] = {
72 [1] = 0x1,
73 [2] = 0x2,
74 [3] = 0x3,
75 [4] = 0x4,
76 [5] = 0x5,
77 [6] = 0x6,
78 [8] = 0x7,
79 [10] = 0x8,
80 [12] = 0x9,
81 [14] = 0xA,
82 [16] = 0xB,
83};
84
85
86static int sunxi_wdt_restart(struct watchdog_device *wdt_dev,
87 unsigned long action, void *data)
88{
89 struct sunxi_wdt_dev *sunxi_wdt = watchdog_get_drvdata(wdt_dev);
90 void __iomem *wdt_base = sunxi_wdt->wdt_base;
91 const struct sunxi_wdt_reg *regs = sunxi_wdt->wdt_regs;
92 u32 val;
93
94
95 val = readl(wdt_base + regs->wdt_cfg);
96 val &= ~(regs->wdt_reset_mask);
97 val |= regs->wdt_reset_val;
98 writel(val, wdt_base + regs->wdt_cfg);
99
100
101 val = readl(wdt_base + regs->wdt_mode);
102 val &= ~(WDT_TIMEOUT_MASK << regs->wdt_timeout_shift);
103 val |= WDT_MODE_EN;
104 writel(val, wdt_base + regs->wdt_mode);
105
106
107
108
109
110 writel(WDT_CTRL_RELOAD, wdt_base + regs->wdt_ctrl);
111
112 while (1) {
113 mdelay(5);
114 val = readl(wdt_base + regs->wdt_mode);
115 val |= WDT_MODE_EN;
116 writel(val, wdt_base + regs->wdt_mode);
117 }
118 return 0;
119}
120
121static int sunxi_wdt_ping(struct watchdog_device *wdt_dev)
122{
123 struct sunxi_wdt_dev *sunxi_wdt = watchdog_get_drvdata(wdt_dev);
124 void __iomem *wdt_base = sunxi_wdt->wdt_base;
125 const struct sunxi_wdt_reg *regs = sunxi_wdt->wdt_regs;
126
127 writel(WDT_CTRL_RELOAD, wdt_base + regs->wdt_ctrl);
128
129 return 0;
130}
131
132static int sunxi_wdt_set_timeout(struct watchdog_device *wdt_dev,
133 unsigned int timeout)
134{
135 struct sunxi_wdt_dev *sunxi_wdt = watchdog_get_drvdata(wdt_dev);
136 void __iomem *wdt_base = sunxi_wdt->wdt_base;
137 const struct sunxi_wdt_reg *regs = sunxi_wdt->wdt_regs;
138 u32 reg;
139
140 if (wdt_timeout_map[timeout] == 0)
141 timeout++;
142
143 sunxi_wdt->wdt_dev.timeout = timeout;
144
145 reg = readl(wdt_base + regs->wdt_mode);
146 reg &= ~(WDT_TIMEOUT_MASK << regs->wdt_timeout_shift);
147 reg |= wdt_timeout_map[timeout] << regs->wdt_timeout_shift;
148 writel(reg, wdt_base + regs->wdt_mode);
149
150 sunxi_wdt_ping(wdt_dev);
151
152 return 0;
153}
154
155static int sunxi_wdt_stop(struct watchdog_device *wdt_dev)
156{
157 struct sunxi_wdt_dev *sunxi_wdt = watchdog_get_drvdata(wdt_dev);
158 void __iomem *wdt_base = sunxi_wdt->wdt_base;
159 const struct sunxi_wdt_reg *regs = sunxi_wdt->wdt_regs;
160
161 writel(0, wdt_base + regs->wdt_mode);
162
163 return 0;
164}
165
166static int sunxi_wdt_start(struct watchdog_device *wdt_dev)
167{
168 u32 reg;
169 struct sunxi_wdt_dev *sunxi_wdt = watchdog_get_drvdata(wdt_dev);
170 void __iomem *wdt_base = sunxi_wdt->wdt_base;
171 const struct sunxi_wdt_reg *regs = sunxi_wdt->wdt_regs;
172 int ret;
173
174 ret = sunxi_wdt_set_timeout(&sunxi_wdt->wdt_dev,
175 sunxi_wdt->wdt_dev.timeout);
176 if (ret < 0)
177 return ret;
178
179
180 reg = readl(wdt_base + regs->wdt_cfg);
181 reg &= ~(regs->wdt_reset_mask);
182 reg |= regs->wdt_reset_val;
183 writel(reg, wdt_base + regs->wdt_cfg);
184
185
186 reg = readl(wdt_base + regs->wdt_mode);
187 reg |= WDT_MODE_EN;
188 writel(reg, wdt_base + regs->wdt_mode);
189
190 return 0;
191}
192
193static const struct watchdog_info sunxi_wdt_info = {
194 .identity = DRV_NAME,
195 .options = WDIOF_SETTIMEOUT |
196 WDIOF_KEEPALIVEPING |
197 WDIOF_MAGICCLOSE,
198};
199
200static const struct watchdog_ops sunxi_wdt_ops = {
201 .owner = THIS_MODULE,
202 .start = sunxi_wdt_start,
203 .stop = sunxi_wdt_stop,
204 .ping = sunxi_wdt_ping,
205 .set_timeout = sunxi_wdt_set_timeout,
206 .restart = sunxi_wdt_restart,
207};
208
209static const struct sunxi_wdt_reg sun4i_wdt_reg = {
210 .wdt_ctrl = 0x00,
211 .wdt_cfg = 0x04,
212 .wdt_mode = 0x04,
213 .wdt_timeout_shift = 3,
214 .wdt_reset_mask = 0x02,
215 .wdt_reset_val = 0x02,
216};
217
218static const struct sunxi_wdt_reg sun6i_wdt_reg = {
219 .wdt_ctrl = 0x10,
220 .wdt_cfg = 0x14,
221 .wdt_mode = 0x18,
222 .wdt_timeout_shift = 4,
223 .wdt_reset_mask = 0x03,
224 .wdt_reset_val = 0x01,
225};
226
227static const struct of_device_id sunxi_wdt_dt_ids[] = {
228 { .compatible = "allwinner,sun4i-a10-wdt", .data = &sun4i_wdt_reg },
229 { .compatible = "allwinner,sun6i-a31-wdt", .data = &sun6i_wdt_reg },
230 { }
231};
232MODULE_DEVICE_TABLE(of, sunxi_wdt_dt_ids);
233
234static int sunxi_wdt_probe(struct platform_device *pdev)
235{
236 struct sunxi_wdt_dev *sunxi_wdt;
237 const struct of_device_id *device;
238 struct resource *res;
239 int err;
240
241 sunxi_wdt = devm_kzalloc(&pdev->dev, sizeof(*sunxi_wdt), GFP_KERNEL);
242 if (!sunxi_wdt)
243 return -EINVAL;
244
245 device = of_match_device(sunxi_wdt_dt_ids, &pdev->dev);
246 if (!device)
247 return -ENODEV;
248
249 sunxi_wdt->wdt_regs = device->data;
250
251 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
252 sunxi_wdt->wdt_base = devm_ioremap_resource(&pdev->dev, res);
253 if (IS_ERR(sunxi_wdt->wdt_base))
254 return PTR_ERR(sunxi_wdt->wdt_base);
255
256 sunxi_wdt->wdt_dev.info = &sunxi_wdt_info;
257 sunxi_wdt->wdt_dev.ops = &sunxi_wdt_ops;
258 sunxi_wdt->wdt_dev.timeout = WDT_MAX_TIMEOUT;
259 sunxi_wdt->wdt_dev.max_timeout = WDT_MAX_TIMEOUT;
260 sunxi_wdt->wdt_dev.min_timeout = WDT_MIN_TIMEOUT;
261 sunxi_wdt->wdt_dev.parent = &pdev->dev;
262
263 watchdog_init_timeout(&sunxi_wdt->wdt_dev, timeout, &pdev->dev);
264 watchdog_set_nowayout(&sunxi_wdt->wdt_dev, nowayout);
265 watchdog_set_restart_priority(&sunxi_wdt->wdt_dev, 128);
266
267 watchdog_set_drvdata(&sunxi_wdt->wdt_dev, sunxi_wdt);
268
269 sunxi_wdt_stop(&sunxi_wdt->wdt_dev);
270
271 watchdog_stop_on_reboot(&sunxi_wdt->wdt_dev);
272 err = devm_watchdog_register_device(&pdev->dev, &sunxi_wdt->wdt_dev);
273 if (unlikely(err))
274 return err;
275
276 dev_info(&pdev->dev, "Watchdog enabled (timeout=%d sec, nowayout=%d)",
277 sunxi_wdt->wdt_dev.timeout, nowayout);
278
279 return 0;
280}
281
282static struct platform_driver sunxi_wdt_driver = {
283 .probe = sunxi_wdt_probe,
284 .driver = {
285 .name = DRV_NAME,
286 .of_match_table = sunxi_wdt_dt_ids,
287 },
288};
289
290module_platform_driver(sunxi_wdt_driver);
291
292module_param(timeout, uint, 0);
293MODULE_PARM_DESC(timeout, "Watchdog heartbeat in seconds");
294
295module_param(nowayout, bool, 0);
296MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started "
297 "(default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
298
299MODULE_LICENSE("GPL");
300MODULE_AUTHOR("Carlo Caione <carlo.caione@gmail.com>");
301MODULE_AUTHOR("Henrik Nordstrom <henrik@henriknordstrom.net>");
302MODULE_DESCRIPTION("sunxi WatchDog Timer Driver");
303MODULE_VERSION(DRV_VERSION);
304
