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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> | |
17 | #include <linux/err.h> | |
18 | #include <linux/init.h> | |
19 | #include <linux/io.h> | |
20 | #include <linux/kernel.h> | |
21 | #include <linux/module.h> | |
22 | #include <linux/moduleparam.h> | |
23 | #include <linux/of.h> | |
24 | #include <linux/platform_device.h> | |
25 | #include <linux/types.h> | |
26 | #include <linux/watchdog.h> | |
27 | ||
28 | #define WDT_MAX_TIMEOUT 16 | |
29 | #define WDT_MIN_TIMEOUT 1 | |
30 | #define WDT_MODE_TIMEOUT(n) ((n) << 3) | |
31 | #define WDT_TIMEOUT_MASK WDT_MODE_TIMEOUT(0x0F) | |
32 | ||
33 | #define WDT_CTRL 0x00 | |
34 | #define WDT_CTRL_RELOAD ((1 << 0) | (0x0a57 << 1)) | |
35 | ||
36 | #define WDT_MODE 0x04 | |
37 | #define WDT_MODE_EN (1 << 0) | |
38 | #define WDT_MODE_RST_EN (1 << 1) | |
39 | ||
40 | #define DRV_NAME "sunxi-wdt" | |
41 | #define DRV_VERSION "1.0" | |
42 | ||
43 | static bool nowayout = WATCHDOG_NOWAYOUT; | |
44 | static unsigned int timeout = WDT_MAX_TIMEOUT; | |
45 | ||
46 | struct sunxi_wdt_dev { | |
47 | struct watchdog_device wdt_dev; | |
48 | void __iomem *wdt_base; | |
49 | }; | |
50 | ||
51 | /* | |
52 | * wdt_timeout_map maps the watchdog timer interval value in seconds to | |
53 | * the value of the register WDT_MODE bit 3:6 | |
54 | * | |
55 | * [timeout seconds] = register value | |
56 | * | |
57 | */ | |
58 | ||
59 | static const int wdt_timeout_map[] = { | |
60 | [1] = 0b0001, /* 1s */ | |
61 | [2] = 0b0010, /* 2s */ | |
62 | [3] = 0b0011, /* 3s */ | |
63 | [4] = 0b0100, /* 4s */ | |
64 | [5] = 0b0101, /* 5s */ | |
65 | [6] = 0b0110, /* 6s */ | |
66 | [8] = 0b0111, /* 8s */ | |
67 | [10] = 0b1000, /* 10s */ | |
68 | [12] = 0b1001, /* 12s */ | |
69 | [14] = 0b1010, /* 14s */ | |
70 | [16] = 0b1011, /* 16s */ | |
71 | }; | |
72 | ||
73 | static int sunxi_wdt_ping(struct watchdog_device *wdt_dev) | |
74 | { | |
75 | struct sunxi_wdt_dev *sunxi_wdt = watchdog_get_drvdata(wdt_dev); | |
76 | void __iomem *wdt_base = sunxi_wdt->wdt_base; | |
77 | ||
78 | iowrite32(WDT_CTRL_RELOAD, wdt_base + WDT_CTRL); | |
79 | ||
80 | return 0; | |
81 | } | |
82 | ||
83 | static int sunxi_wdt_set_timeout(struct watchdog_device *wdt_dev, | |
84 | unsigned int timeout) | |
85 | { | |
86 | struct sunxi_wdt_dev *sunxi_wdt = watchdog_get_drvdata(wdt_dev); | |
87 | void __iomem *wdt_base = sunxi_wdt->wdt_base; | |
88 | u32 reg; | |
89 | ||
90 | if (wdt_timeout_map[timeout] == 0) | |
91 | timeout++; | |
92 | ||
93 | sunxi_wdt->wdt_dev.timeout = timeout; | |
94 | ||
95 | reg = ioread32(wdt_base + WDT_MODE); | |
96 | reg &= ~WDT_TIMEOUT_MASK; | |
97 | reg |= WDT_MODE_TIMEOUT(wdt_timeout_map[timeout]); | |
98 | iowrite32(reg, wdt_base + WDT_MODE); | |
99 | ||
100 | sunxi_wdt_ping(wdt_dev); | |
101 | ||
102 | return 0; | |
103 | } | |
104 | ||
105 | static int sunxi_wdt_stop(struct watchdog_device *wdt_dev) | |
106 | { | |
107 | struct sunxi_wdt_dev *sunxi_wdt = watchdog_get_drvdata(wdt_dev); | |
108 | void __iomem *wdt_base = sunxi_wdt->wdt_base; | |
109 | ||
110 | iowrite32(0, wdt_base + WDT_MODE); | |
111 | ||
112 | return 0; | |
113 | } | |
114 | ||
115 | static int sunxi_wdt_start(struct watchdog_device *wdt_dev) | |
116 | { | |
117 | u32 reg; | |
118 | struct sunxi_wdt_dev *sunxi_wdt = watchdog_get_drvdata(wdt_dev); | |
119 | void __iomem *wdt_base = sunxi_wdt->wdt_base; | |
120 | int ret; | |
121 | ||
122 | ret = sunxi_wdt_set_timeout(&sunxi_wdt->wdt_dev, | |
123 | sunxi_wdt->wdt_dev.timeout); | |
124 | if (ret < 0) | |
125 | return ret; | |
126 | ||
127 | reg = ioread32(wdt_base + WDT_MODE); | |
128 | reg |= (WDT_MODE_RST_EN | WDT_MODE_EN); | |
129 | iowrite32(reg, wdt_base + WDT_MODE); | |
130 | ||
131 | return 0; | |
132 | } | |
133 | ||
134 | static const struct watchdog_info sunxi_wdt_info = { | |
135 | .identity = DRV_NAME, | |
136 | .options = WDIOF_SETTIMEOUT | | |
137 | WDIOF_KEEPALIVEPING | | |
138 | WDIOF_MAGICCLOSE, | |
139 | }; | |
140 | ||
141 | static const struct watchdog_ops sunxi_wdt_ops = { | |
142 | .owner = THIS_MODULE, | |
143 | .start = sunxi_wdt_start, | |
144 | .stop = sunxi_wdt_stop, | |
145 | .ping = sunxi_wdt_ping, | |
146 | .set_timeout = sunxi_wdt_set_timeout, | |
147 | }; | |
148 | ||
1d5898b4 | 149 | static int sunxi_wdt_probe(struct platform_device *pdev) |
d00680ed CC |
150 | { |
151 | struct sunxi_wdt_dev *sunxi_wdt; | |
152 | struct resource *res; | |
153 | int err; | |
154 | ||
155 | sunxi_wdt = devm_kzalloc(&pdev->dev, sizeof(*sunxi_wdt), GFP_KERNEL); | |
156 | if (!sunxi_wdt) | |
157 | return -EINVAL; | |
158 | ||
159 | platform_set_drvdata(pdev, sunxi_wdt); | |
160 | ||
161 | res = platform_get_resource(pdev, IORESOURCE_MEM, 0); | |
162 | sunxi_wdt->wdt_base = devm_ioremap_resource(&pdev->dev, res); | |
163 | if (IS_ERR(sunxi_wdt->wdt_base)) | |
164 | return PTR_ERR(sunxi_wdt->wdt_base); | |
165 | ||
166 | sunxi_wdt->wdt_dev.info = &sunxi_wdt_info; | |
167 | sunxi_wdt->wdt_dev.ops = &sunxi_wdt_ops; | |
168 | sunxi_wdt->wdt_dev.timeout = WDT_MAX_TIMEOUT; | |
169 | sunxi_wdt->wdt_dev.max_timeout = WDT_MAX_TIMEOUT; | |
170 | sunxi_wdt->wdt_dev.min_timeout = WDT_MIN_TIMEOUT; | |
171 | sunxi_wdt->wdt_dev.parent = &pdev->dev; | |
172 | ||
173 | watchdog_init_timeout(&sunxi_wdt->wdt_dev, timeout, &pdev->dev); | |
174 | watchdog_set_nowayout(&sunxi_wdt->wdt_dev, nowayout); | |
175 | ||
176 | watchdog_set_drvdata(&sunxi_wdt->wdt_dev, sunxi_wdt); | |
177 | ||
178 | sunxi_wdt_stop(&sunxi_wdt->wdt_dev); | |
179 | ||
180 | err = watchdog_register_device(&sunxi_wdt->wdt_dev); | |
181 | if (unlikely(err)) | |
182 | return err; | |
183 | ||
184 | dev_info(&pdev->dev, "Watchdog enabled (timeout=%d sec, nowayout=%d)", | |
185 | sunxi_wdt->wdt_dev.timeout, nowayout); | |
186 | ||
187 | return 0; | |
188 | } | |
189 | ||
1d5898b4 | 190 | static int sunxi_wdt_remove(struct platform_device *pdev) |
d00680ed CC |
191 | { |
192 | struct sunxi_wdt_dev *sunxi_wdt = platform_get_drvdata(pdev); | |
193 | ||
194 | watchdog_unregister_device(&sunxi_wdt->wdt_dev); | |
195 | watchdog_set_drvdata(&sunxi_wdt->wdt_dev, NULL); | |
196 | ||
197 | return 0; | |
198 | } | |
199 | ||
200 | static void sunxi_wdt_shutdown(struct platform_device *pdev) | |
201 | { | |
202 | struct sunxi_wdt_dev *sunxi_wdt = platform_get_drvdata(pdev); | |
203 | ||
204 | sunxi_wdt_stop(&sunxi_wdt->wdt_dev); | |
205 | } | |
206 | ||
207 | static const struct of_device_id sunxi_wdt_dt_ids[] = { | |
208 | { .compatible = "allwinner,sun4i-wdt" }, | |
209 | { /* sentinel */ } | |
210 | }; | |
211 | MODULE_DEVICE_TABLE(of, sunxi_wdt_dt_ids); | |
212 | ||
213 | static struct platform_driver sunxi_wdt_driver = { | |
214 | .probe = sunxi_wdt_probe, | |
215 | .remove = sunxi_wdt_remove, | |
216 | .shutdown = sunxi_wdt_shutdown, | |
217 | .driver = { | |
218 | .owner = THIS_MODULE, | |
219 | .name = DRV_NAME, | |
220 | .of_match_table = of_match_ptr(sunxi_wdt_dt_ids) | |
221 | }, | |
222 | }; | |
223 | ||
224 | module_platform_driver(sunxi_wdt_driver); | |
225 | ||
226 | module_param(timeout, uint, 0); | |
227 | MODULE_PARM_DESC(timeout, "Watchdog heartbeat in seconds"); | |
228 | ||
229 | module_param(nowayout, bool, 0); | |
230 | MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started " | |
231 | "(default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); | |
232 | ||
233 | MODULE_LICENSE("GPL"); | |
234 | MODULE_AUTHOR("Carlo Caione <carlo.caione@gmail.com>"); | |
235 | MODULE_AUTHOR("Henrik Nordstrom <henrik@henriknordstrom.net>"); | |
236 | MODULE_DESCRIPTION("sunxi WatchDog Timer Driver"); | |
237 | MODULE_VERSION(DRV_VERSION); |