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d00680ed CC |
1 | /* |
2 | * sunxi Watchdog Driver | |
3 | * | |
4 | * Copyright (c) 2013 Carlo Caione | |
5 | * 2012 Henrik Nordstrom | |
6 | * | |
7 | * This program is free software; you can redistribute it and/or | |
8 | * modify it under the terms of the GNU General Public License | |
9 | * as published by the Free Software Foundation; either version | |
10 | * 2 of the License, or (at your option) any later version. | |
11 | * | |
12 | * Based on xen_wdt.c | |
13 | * (c) Copyright 2010 Novell, Inc. | |
14 | */ | |
15 | ||
16 | #include <linux/clk.h> | |
440e96bc | 17 | #include <linux/delay.h> |
d00680ed CC |
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/platform_device.h> | |
440e96bc | 26 | #include <linux/reboot.h> |
d00680ed CC |
27 | #include <linux/types.h> |
28 | #include <linux/watchdog.h> | |
29 | ||
440e96bc MR |
30 | #include <asm/system_misc.h> |
31 | ||
d00680ed CC |
32 | #define WDT_MAX_TIMEOUT 16 |
33 | #define WDT_MIN_TIMEOUT 1 | |
34 | #define WDT_MODE_TIMEOUT(n) ((n) << 3) | |
35 | #define WDT_TIMEOUT_MASK WDT_MODE_TIMEOUT(0x0F) | |
36 | ||
37 | #define WDT_CTRL 0x00 | |
38 | #define WDT_CTRL_RELOAD ((1 << 0) | (0x0a57 << 1)) | |
39 | ||
40 | #define WDT_MODE 0x04 | |
41 | #define WDT_MODE_EN (1 << 0) | |
42 | #define WDT_MODE_RST_EN (1 << 1) | |
43 | ||
44 | #define DRV_NAME "sunxi-wdt" | |
45 | #define DRV_VERSION "1.0" | |
46 | ||
47 | static bool nowayout = WATCHDOG_NOWAYOUT; | |
48 | static unsigned int timeout = WDT_MAX_TIMEOUT; | |
49 | ||
50 | struct sunxi_wdt_dev { | |
51 | struct watchdog_device wdt_dev; | |
52 | void __iomem *wdt_base; | |
53 | }; | |
54 | ||
55 | /* | |
56 | * wdt_timeout_map maps the watchdog timer interval value in seconds to | |
57 | * the value of the register WDT_MODE bit 3:6 | |
58 | * | |
59 | * [timeout seconds] = register value | |
60 | * | |
61 | */ | |
62 | ||
63 | static const int wdt_timeout_map[] = { | |
51ee34ab EL |
64 | [1] = 0x1, /* 1s */ |
65 | [2] = 0x2, /* 2s */ | |
66 | [3] = 0x3, /* 3s */ | |
67 | [4] = 0x4, /* 4s */ | |
68 | [5] = 0x5, /* 5s */ | |
69 | [6] = 0x6, /* 6s */ | |
70 | [8] = 0x7, /* 8s */ | |
71 | [10] = 0x8, /* 10s */ | |
72 | [12] = 0x9, /* 12s */ | |
73 | [14] = 0xA, /* 14s */ | |
74 | [16] = 0xB, /* 16s */ | |
d00680ed CC |
75 | }; |
76 | ||
440e96bc MR |
77 | static void __iomem *reboot_wdt_base; |
78 | ||
79 | static void sun4i_wdt_restart(enum reboot_mode mode, const char *cmd) | |
80 | { | |
81 | /* Enable timer and set reset bit in the watchdog */ | |
82 | writel(WDT_MODE_EN | WDT_MODE_RST_EN, reboot_wdt_base + WDT_MODE); | |
83 | ||
84 | /* | |
85 | * Restart the watchdog. The default (and lowest) interval | |
86 | * value for the watchdog is 0.5s. | |
87 | */ | |
88 | writel(WDT_CTRL_RELOAD, reboot_wdt_base + WDT_CTRL); | |
89 | ||
90 | while (1) { | |
91 | mdelay(5); | |
92 | writel(WDT_MODE_EN | WDT_MODE_RST_EN, | |
93 | reboot_wdt_base + WDT_MODE); | |
94 | } | |
95 | } | |
96 | ||
d00680ed CC |
97 | static int sunxi_wdt_ping(struct watchdog_device *wdt_dev) |
98 | { | |
99 | struct sunxi_wdt_dev *sunxi_wdt = watchdog_get_drvdata(wdt_dev); | |
100 | void __iomem *wdt_base = sunxi_wdt->wdt_base; | |
101 | ||
102 | iowrite32(WDT_CTRL_RELOAD, wdt_base + WDT_CTRL); | |
103 | ||
104 | return 0; | |
105 | } | |
106 | ||
107 | static int sunxi_wdt_set_timeout(struct watchdog_device *wdt_dev, | |
108 | unsigned int timeout) | |
109 | { | |
110 | struct sunxi_wdt_dev *sunxi_wdt = watchdog_get_drvdata(wdt_dev); | |
111 | void __iomem *wdt_base = sunxi_wdt->wdt_base; | |
112 | u32 reg; | |
113 | ||
114 | if (wdt_timeout_map[timeout] == 0) | |
115 | timeout++; | |
116 | ||
117 | sunxi_wdt->wdt_dev.timeout = timeout; | |
118 | ||
119 | reg = ioread32(wdt_base + WDT_MODE); | |
120 | reg &= ~WDT_TIMEOUT_MASK; | |
121 | reg |= WDT_MODE_TIMEOUT(wdt_timeout_map[timeout]); | |
122 | iowrite32(reg, wdt_base + WDT_MODE); | |
123 | ||
124 | sunxi_wdt_ping(wdt_dev); | |
125 | ||
126 | return 0; | |
127 | } | |
128 | ||
129 | static int sunxi_wdt_stop(struct watchdog_device *wdt_dev) | |
130 | { | |
131 | struct sunxi_wdt_dev *sunxi_wdt = watchdog_get_drvdata(wdt_dev); | |
132 | void __iomem *wdt_base = sunxi_wdt->wdt_base; | |
133 | ||
134 | iowrite32(0, wdt_base + WDT_MODE); | |
135 | ||
136 | return 0; | |
137 | } | |
138 | ||
139 | static int sunxi_wdt_start(struct watchdog_device *wdt_dev) | |
140 | { | |
141 | u32 reg; | |
142 | struct sunxi_wdt_dev *sunxi_wdt = watchdog_get_drvdata(wdt_dev); | |
143 | void __iomem *wdt_base = sunxi_wdt->wdt_base; | |
144 | int ret; | |
145 | ||
146 | ret = sunxi_wdt_set_timeout(&sunxi_wdt->wdt_dev, | |
147 | sunxi_wdt->wdt_dev.timeout); | |
148 | if (ret < 0) | |
149 | return ret; | |
150 | ||
151 | reg = ioread32(wdt_base + WDT_MODE); | |
152 | reg |= (WDT_MODE_RST_EN | WDT_MODE_EN); | |
153 | iowrite32(reg, wdt_base + WDT_MODE); | |
154 | ||
155 | return 0; | |
156 | } | |
157 | ||
158 | static const struct watchdog_info sunxi_wdt_info = { | |
159 | .identity = DRV_NAME, | |
160 | .options = WDIOF_SETTIMEOUT | | |
161 | WDIOF_KEEPALIVEPING | | |
162 | WDIOF_MAGICCLOSE, | |
163 | }; | |
164 | ||
165 | static const struct watchdog_ops sunxi_wdt_ops = { | |
166 | .owner = THIS_MODULE, | |
167 | .start = sunxi_wdt_start, | |
168 | .stop = sunxi_wdt_stop, | |
169 | .ping = sunxi_wdt_ping, | |
170 | .set_timeout = sunxi_wdt_set_timeout, | |
171 | }; | |
172 | ||
1d5898b4 | 173 | static int sunxi_wdt_probe(struct platform_device *pdev) |
d00680ed CC |
174 | { |
175 | struct sunxi_wdt_dev *sunxi_wdt; | |
176 | struct resource *res; | |
177 | int err; | |
178 | ||
179 | sunxi_wdt = devm_kzalloc(&pdev->dev, sizeof(*sunxi_wdt), GFP_KERNEL); | |
180 | if (!sunxi_wdt) | |
181 | return -EINVAL; | |
182 | ||
183 | platform_set_drvdata(pdev, sunxi_wdt); | |
184 | ||
185 | res = platform_get_resource(pdev, IORESOURCE_MEM, 0); | |
186 | sunxi_wdt->wdt_base = devm_ioremap_resource(&pdev->dev, res); | |
187 | if (IS_ERR(sunxi_wdt->wdt_base)) | |
188 | return PTR_ERR(sunxi_wdt->wdt_base); | |
189 | ||
190 | sunxi_wdt->wdt_dev.info = &sunxi_wdt_info; | |
191 | sunxi_wdt->wdt_dev.ops = &sunxi_wdt_ops; | |
192 | sunxi_wdt->wdt_dev.timeout = WDT_MAX_TIMEOUT; | |
193 | sunxi_wdt->wdt_dev.max_timeout = WDT_MAX_TIMEOUT; | |
194 | sunxi_wdt->wdt_dev.min_timeout = WDT_MIN_TIMEOUT; | |
195 | sunxi_wdt->wdt_dev.parent = &pdev->dev; | |
196 | ||
197 | watchdog_init_timeout(&sunxi_wdt->wdt_dev, timeout, &pdev->dev); | |
198 | watchdog_set_nowayout(&sunxi_wdt->wdt_dev, nowayout); | |
199 | ||
200 | watchdog_set_drvdata(&sunxi_wdt->wdt_dev, sunxi_wdt); | |
201 | ||
202 | sunxi_wdt_stop(&sunxi_wdt->wdt_dev); | |
203 | ||
204 | err = watchdog_register_device(&sunxi_wdt->wdt_dev); | |
205 | if (unlikely(err)) | |
206 | return err; | |
207 | ||
440e96bc MR |
208 | reboot_wdt_base = sunxi_wdt->wdt_base; |
209 | arm_pm_restart = sun4i_wdt_restart; | |
210 | ||
d00680ed CC |
211 | dev_info(&pdev->dev, "Watchdog enabled (timeout=%d sec, nowayout=%d)", |
212 | sunxi_wdt->wdt_dev.timeout, nowayout); | |
213 | ||
214 | return 0; | |
215 | } | |
216 | ||
1d5898b4 | 217 | static int sunxi_wdt_remove(struct platform_device *pdev) |
d00680ed CC |
218 | { |
219 | struct sunxi_wdt_dev *sunxi_wdt = platform_get_drvdata(pdev); | |
220 | ||
440e96bc MR |
221 | arm_pm_restart = NULL; |
222 | ||
d00680ed CC |
223 | watchdog_unregister_device(&sunxi_wdt->wdt_dev); |
224 | watchdog_set_drvdata(&sunxi_wdt->wdt_dev, NULL); | |
225 | ||
226 | return 0; | |
227 | } | |
228 | ||
229 | static void sunxi_wdt_shutdown(struct platform_device *pdev) | |
230 | { | |
231 | struct sunxi_wdt_dev *sunxi_wdt = platform_get_drvdata(pdev); | |
232 | ||
233 | sunxi_wdt_stop(&sunxi_wdt->wdt_dev); | |
234 | } | |
235 | ||
236 | static const struct of_device_id sunxi_wdt_dt_ids[] = { | |
b0f1d8be | 237 | { .compatible = "allwinner,sun4i-a10-wdt" }, |
d00680ed CC |
238 | { /* sentinel */ } |
239 | }; | |
240 | MODULE_DEVICE_TABLE(of, sunxi_wdt_dt_ids); | |
241 | ||
242 | static struct platform_driver sunxi_wdt_driver = { | |
243 | .probe = sunxi_wdt_probe, | |
244 | .remove = sunxi_wdt_remove, | |
245 | .shutdown = sunxi_wdt_shutdown, | |
246 | .driver = { | |
247 | .owner = THIS_MODULE, | |
248 | .name = DRV_NAME, | |
85eee819 | 249 | .of_match_table = sunxi_wdt_dt_ids, |
d00680ed CC |
250 | }, |
251 | }; | |
252 | ||
253 | module_platform_driver(sunxi_wdt_driver); | |
254 | ||
255 | module_param(timeout, uint, 0); | |
256 | MODULE_PARM_DESC(timeout, "Watchdog heartbeat in seconds"); | |
257 | ||
258 | module_param(nowayout, bool, 0); | |
259 | MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started " | |
260 | "(default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); | |
261 | ||
262 | MODULE_LICENSE("GPL"); | |
263 | MODULE_AUTHOR("Carlo Caione <carlo.caione@gmail.com>"); | |
264 | MODULE_AUTHOR("Henrik Nordstrom <henrik@henriknordstrom.net>"); | |
265 | MODULE_DESCRIPTION("sunxi WatchDog Timer Driver"); | |
266 | MODULE_VERSION(DRV_VERSION); |