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98078ca3 HCO |
1 | /* |
2 | * Copyright (C) 2016 National Instruments Corp. | |
3 | * | |
4 | * This program is free software; you can redistribute it and/or modify | |
5 | * it under the terms of the GNU General Public License as published by | |
6 | * the Free Software Foundation; either version 2 of the License, or | |
7 | * (at your option) any later version. | |
8 | * | |
9 | * This program is distributed in the hope that it will be useful, | |
10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
12 | * GNU General Public License for more details. | |
13 | */ | |
14 | ||
15 | #include <linux/acpi.h> | |
16 | #include <linux/bitops.h> | |
17 | #include <linux/device.h> | |
18 | #include <linux/io.h> | |
19 | #include <linux/module.h> | |
20 | #include <linux/platform_device.h> | |
21 | #include <linux/watchdog.h> | |
22 | ||
23 | #define LOCK 0xA5 | |
24 | #define UNLOCK 0x5A | |
25 | ||
26 | #define WDT_CTRL_RESET_EN BIT(7) | |
27 | #define WDT_RELOAD_PORT_EN BIT(7) | |
28 | ||
29 | #define WDT_CTRL 1 | |
30 | #define WDT_RELOAD_CTRL 2 | |
31 | #define WDT_PRESET_PRESCALE 4 | |
32 | #define WDT_REG_LOCK 5 | |
33 | #define WDT_COUNT 6 | |
34 | #define WDT_RELOAD_PORT 7 | |
35 | ||
36 | #define WDT_MIN_TIMEOUT 1 | |
37 | #define WDT_MAX_TIMEOUT 464 | |
38 | #define WDT_DEFAULT_TIMEOUT 80 | |
39 | ||
40 | #define WDT_MAX_COUNTER 15 | |
41 | ||
42 | static unsigned int timeout; | |
43 | module_param(timeout, uint, 0); | |
44 | MODULE_PARM_DESC(timeout, | |
45 | "Watchdog timeout in seconds. (default=" | |
46 | __MODULE_STRING(WDT_DEFAULT_TIMEOUT) ")"); | |
47 | ||
48 | static bool nowayout = WATCHDOG_NOWAYOUT; | |
49 | module_param(nowayout, bool, 0); | |
50 | MODULE_PARM_DESC(nowayout, | |
51 | "Watchdog cannot be stopped once started. (default=" | |
52 | __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); | |
53 | ||
54 | struct nic7018_wdt { | |
55 | u16 io_base; | |
56 | u32 period; | |
57 | struct watchdog_device wdd; | |
58 | }; | |
59 | ||
60 | struct nic7018_config { | |
61 | u32 period; | |
62 | u8 divider; | |
63 | }; | |
64 | ||
65 | static const struct nic7018_config nic7018_configs[] = { | |
66 | { 2, 4 }, | |
67 | { 32, 5 }, | |
68 | }; | |
69 | ||
70 | static inline u32 nic7018_timeout(u32 period, u8 counter) | |
71 | { | |
72 | return period * counter - period / 2; | |
73 | } | |
74 | ||
75 | static const struct nic7018_config *nic7018_get_config(u32 timeout, | |
76 | u8 *counter) | |
77 | { | |
78 | const struct nic7018_config *config; | |
79 | u8 count; | |
80 | ||
81 | if (timeout < 30 && timeout != 16) { | |
82 | config = &nic7018_configs[0]; | |
83 | count = timeout / 2 + 1; | |
84 | } else { | |
85 | config = &nic7018_configs[1]; | |
86 | count = DIV_ROUND_UP(timeout + 16, 32); | |
87 | ||
88 | if (count > WDT_MAX_COUNTER) | |
89 | count = WDT_MAX_COUNTER; | |
90 | } | |
91 | *counter = count; | |
92 | return config; | |
93 | } | |
94 | ||
95 | static int nic7018_set_timeout(struct watchdog_device *wdd, | |
96 | unsigned int timeout) | |
97 | { | |
98 | struct nic7018_wdt *wdt = watchdog_get_drvdata(wdd); | |
99 | const struct nic7018_config *config; | |
100 | u8 counter; | |
101 | ||
102 | config = nic7018_get_config(timeout, &counter); | |
103 | ||
104 | outb(counter << 4 | config->divider, | |
105 | wdt->io_base + WDT_PRESET_PRESCALE); | |
106 | ||
107 | wdd->timeout = nic7018_timeout(config->period, counter); | |
108 | wdt->period = config->period; | |
109 | ||
110 | return 0; | |
111 | } | |
112 | ||
113 | static int nic7018_start(struct watchdog_device *wdd) | |
114 | { | |
115 | struct nic7018_wdt *wdt = watchdog_get_drvdata(wdd); | |
116 | u8 control; | |
117 | ||
118 | nic7018_set_timeout(wdd, wdd->timeout); | |
119 | ||
120 | control = inb(wdt->io_base + WDT_RELOAD_CTRL); | |
121 | outb(control | WDT_RELOAD_PORT_EN, wdt->io_base + WDT_RELOAD_CTRL); | |
122 | ||
123 | outb(1, wdt->io_base + WDT_RELOAD_PORT); | |
124 | ||
125 | control = inb(wdt->io_base + WDT_CTRL); | |
126 | outb(control | WDT_CTRL_RESET_EN, wdt->io_base + WDT_CTRL); | |
127 | ||
128 | return 0; | |
129 | } | |
130 | ||
131 | static int nic7018_stop(struct watchdog_device *wdd) | |
132 | { | |
133 | struct nic7018_wdt *wdt = watchdog_get_drvdata(wdd); | |
134 | ||
135 | outb(0, wdt->io_base + WDT_CTRL); | |
136 | outb(0, wdt->io_base + WDT_RELOAD_CTRL); | |
137 | outb(0xF0, wdt->io_base + WDT_PRESET_PRESCALE); | |
138 | ||
139 | return 0; | |
140 | } | |
141 | ||
142 | static int nic7018_ping(struct watchdog_device *wdd) | |
143 | { | |
144 | struct nic7018_wdt *wdt = watchdog_get_drvdata(wdd); | |
145 | ||
146 | outb(1, wdt->io_base + WDT_RELOAD_PORT); | |
147 | ||
148 | return 0; | |
149 | } | |
150 | ||
151 | static unsigned int nic7018_get_timeleft(struct watchdog_device *wdd) | |
152 | { | |
153 | struct nic7018_wdt *wdt = watchdog_get_drvdata(wdd); | |
154 | u8 count; | |
155 | ||
156 | count = inb(wdt->io_base + WDT_COUNT) & 0xF; | |
157 | if (!count) | |
158 | return 0; | |
159 | ||
160 | return nic7018_timeout(wdt->period, count); | |
161 | } | |
162 | ||
163 | static const struct watchdog_info nic7018_wdd_info = { | |
164 | .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE, | |
165 | .identity = "NIC7018 Watchdog", | |
166 | }; | |
167 | ||
168 | static const struct watchdog_ops nic7018_wdd_ops = { | |
169 | .owner = THIS_MODULE, | |
170 | .start = nic7018_start, | |
171 | .stop = nic7018_stop, | |
172 | .ping = nic7018_ping, | |
173 | .set_timeout = nic7018_set_timeout, | |
174 | .get_timeleft = nic7018_get_timeleft, | |
175 | }; | |
176 | ||
177 | static int nic7018_probe(struct platform_device *pdev) | |
178 | { | |
179 | struct device *dev = &pdev->dev; | |
180 | struct watchdog_device *wdd; | |
181 | struct nic7018_wdt *wdt; | |
182 | struct resource *io_rc; | |
183 | int ret; | |
184 | ||
185 | wdt = devm_kzalloc(dev, sizeof(*wdt), GFP_KERNEL); | |
186 | if (!wdt) | |
187 | return -ENOMEM; | |
188 | ||
189 | platform_set_drvdata(pdev, wdt); | |
190 | ||
191 | io_rc = platform_get_resource(pdev, IORESOURCE_IO, 0); | |
192 | if (!io_rc) { | |
193 | dev_err(dev, "missing IO resources\n"); | |
194 | return -EINVAL; | |
195 | } | |
196 | ||
197 | if (!devm_request_region(dev, io_rc->start, resource_size(io_rc), | |
198 | KBUILD_MODNAME)) { | |
199 | dev_err(dev, "failed to get IO region\n"); | |
200 | return -EBUSY; | |
201 | } | |
202 | ||
203 | wdt->io_base = io_rc->start; | |
204 | wdd = &wdt->wdd; | |
205 | wdd->info = &nic7018_wdd_info; | |
206 | wdd->ops = &nic7018_wdd_ops; | |
207 | wdd->min_timeout = WDT_MIN_TIMEOUT; | |
208 | wdd->max_timeout = WDT_MAX_TIMEOUT; | |
209 | wdd->timeout = WDT_DEFAULT_TIMEOUT; | |
210 | wdd->parent = dev; | |
211 | ||
212 | watchdog_set_drvdata(wdd, wdt); | |
213 | watchdog_set_nowayout(wdd, nowayout); | |
214 | ||
215 | ret = watchdog_init_timeout(wdd, timeout, dev); | |
216 | if (ret) | |
217 | dev_warn(dev, "unable to set timeout value, using default\n"); | |
218 | ||
219 | /* Unlock WDT register */ | |
220 | outb(UNLOCK, wdt->io_base + WDT_REG_LOCK); | |
221 | ||
222 | ret = watchdog_register_device(wdd); | |
223 | if (ret) { | |
224 | outb(LOCK, wdt->io_base + WDT_REG_LOCK); | |
225 | dev_err(dev, "failed to register watchdog\n"); | |
226 | return ret; | |
227 | } | |
228 | ||
229 | dev_dbg(dev, "io_base=0x%04X, timeout=%d, nowayout=%d\n", | |
230 | wdt->io_base, timeout, nowayout); | |
231 | return 0; | |
232 | } | |
233 | ||
234 | static int nic7018_remove(struct platform_device *pdev) | |
235 | { | |
236 | struct nic7018_wdt *wdt = platform_get_drvdata(pdev); | |
237 | ||
238 | watchdog_unregister_device(&wdt->wdd); | |
239 | ||
240 | /* Lock WDT register */ | |
241 | outb(LOCK, wdt->io_base + WDT_REG_LOCK); | |
242 | ||
243 | return 0; | |
244 | } | |
245 | ||
246 | static const struct acpi_device_id nic7018_device_ids[] = { | |
247 | {"NIC7018", 0}, | |
248 | {"", 0}, | |
249 | }; | |
250 | MODULE_DEVICE_TABLE(acpi, nic7018_device_ids); | |
251 | ||
252 | static struct platform_driver watchdog_driver = { | |
253 | .probe = nic7018_probe, | |
254 | .remove = nic7018_remove, | |
255 | .driver = { | |
256 | .name = KBUILD_MODNAME, | |
257 | .acpi_match_table = ACPI_PTR(nic7018_device_ids), | |
258 | }, | |
259 | }; | |
260 | ||
261 | module_platform_driver(watchdog_driver); | |
262 | ||
263 | MODULE_DESCRIPTION("National Instruments NIC7018 Watchdog driver"); | |
264 | MODULE_AUTHOR("Hui Chun Ong <hui.chun.ong@ni.com>"); | |
265 | MODULE_LICENSE("GPL"); |