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c942fddf | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
98078ca3 HCO |
2 | /* |
3 | * Copyright (C) 2016 National Instruments Corp. | |
98078ca3 HCO |
4 | */ |
5 | ||
6 | #include <linux/acpi.h> | |
7 | #include <linux/bitops.h> | |
8 | #include <linux/device.h> | |
9 | #include <linux/io.h> | |
10 | #include <linux/module.h> | |
11 | #include <linux/platform_device.h> | |
12 | #include <linux/watchdog.h> | |
13 | ||
14 | #define LOCK 0xA5 | |
15 | #define UNLOCK 0x5A | |
16 | ||
17 | #define WDT_CTRL_RESET_EN BIT(7) | |
18 | #define WDT_RELOAD_PORT_EN BIT(7) | |
19 | ||
20 | #define WDT_CTRL 1 | |
21 | #define WDT_RELOAD_CTRL 2 | |
22 | #define WDT_PRESET_PRESCALE 4 | |
23 | #define WDT_REG_LOCK 5 | |
24 | #define WDT_COUNT 6 | |
25 | #define WDT_RELOAD_PORT 7 | |
26 | ||
27 | #define WDT_MIN_TIMEOUT 1 | |
28 | #define WDT_MAX_TIMEOUT 464 | |
29 | #define WDT_DEFAULT_TIMEOUT 80 | |
30 | ||
31 | #define WDT_MAX_COUNTER 15 | |
32 | ||
33 | static unsigned int timeout; | |
34 | module_param(timeout, uint, 0); | |
35 | MODULE_PARM_DESC(timeout, | |
36 | "Watchdog timeout in seconds. (default=" | |
37 | __MODULE_STRING(WDT_DEFAULT_TIMEOUT) ")"); | |
38 | ||
39 | static bool nowayout = WATCHDOG_NOWAYOUT; | |
40 | module_param(nowayout, bool, 0); | |
41 | MODULE_PARM_DESC(nowayout, | |
42 | "Watchdog cannot be stopped once started. (default=" | |
43 | __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); | |
44 | ||
45 | struct nic7018_wdt { | |
46 | u16 io_base; | |
47 | u32 period; | |
48 | struct watchdog_device wdd; | |
49 | }; | |
50 | ||
51 | struct nic7018_config { | |
52 | u32 period; | |
53 | u8 divider; | |
54 | }; | |
55 | ||
56 | static const struct nic7018_config nic7018_configs[] = { | |
57 | { 2, 4 }, | |
58 | { 32, 5 }, | |
59 | }; | |
60 | ||
61 | static inline u32 nic7018_timeout(u32 period, u8 counter) | |
62 | { | |
63 | return period * counter - period / 2; | |
64 | } | |
65 | ||
66 | static const struct nic7018_config *nic7018_get_config(u32 timeout, | |
67 | u8 *counter) | |
68 | { | |
69 | const struct nic7018_config *config; | |
70 | u8 count; | |
71 | ||
72 | if (timeout < 30 && timeout != 16) { | |
73 | config = &nic7018_configs[0]; | |
74 | count = timeout / 2 + 1; | |
75 | } else { | |
76 | config = &nic7018_configs[1]; | |
77 | count = DIV_ROUND_UP(timeout + 16, 32); | |
78 | ||
79 | if (count > WDT_MAX_COUNTER) | |
80 | count = WDT_MAX_COUNTER; | |
81 | } | |
82 | *counter = count; | |
83 | return config; | |
84 | } | |
85 | ||
86 | static int nic7018_set_timeout(struct watchdog_device *wdd, | |
87 | unsigned int timeout) | |
88 | { | |
89 | struct nic7018_wdt *wdt = watchdog_get_drvdata(wdd); | |
90 | const struct nic7018_config *config; | |
91 | u8 counter; | |
92 | ||
93 | config = nic7018_get_config(timeout, &counter); | |
94 | ||
95 | outb(counter << 4 | config->divider, | |
96 | wdt->io_base + WDT_PRESET_PRESCALE); | |
97 | ||
98 | wdd->timeout = nic7018_timeout(config->period, counter); | |
99 | wdt->period = config->period; | |
100 | ||
101 | return 0; | |
102 | } | |
103 | ||
104 | static int nic7018_start(struct watchdog_device *wdd) | |
105 | { | |
106 | struct nic7018_wdt *wdt = watchdog_get_drvdata(wdd); | |
107 | u8 control; | |
108 | ||
109 | nic7018_set_timeout(wdd, wdd->timeout); | |
110 | ||
111 | control = inb(wdt->io_base + WDT_RELOAD_CTRL); | |
112 | outb(control | WDT_RELOAD_PORT_EN, wdt->io_base + WDT_RELOAD_CTRL); | |
113 | ||
114 | outb(1, wdt->io_base + WDT_RELOAD_PORT); | |
115 | ||
116 | control = inb(wdt->io_base + WDT_CTRL); | |
117 | outb(control | WDT_CTRL_RESET_EN, wdt->io_base + WDT_CTRL); | |
118 | ||
119 | return 0; | |
120 | } | |
121 | ||
122 | static int nic7018_stop(struct watchdog_device *wdd) | |
123 | { | |
124 | struct nic7018_wdt *wdt = watchdog_get_drvdata(wdd); | |
125 | ||
126 | outb(0, wdt->io_base + WDT_CTRL); | |
127 | outb(0, wdt->io_base + WDT_RELOAD_CTRL); | |
128 | outb(0xF0, wdt->io_base + WDT_PRESET_PRESCALE); | |
129 | ||
130 | return 0; | |
131 | } | |
132 | ||
133 | static int nic7018_ping(struct watchdog_device *wdd) | |
134 | { | |
135 | struct nic7018_wdt *wdt = watchdog_get_drvdata(wdd); | |
136 | ||
137 | outb(1, wdt->io_base + WDT_RELOAD_PORT); | |
138 | ||
139 | return 0; | |
140 | } | |
141 | ||
142 | static unsigned int nic7018_get_timeleft(struct watchdog_device *wdd) | |
143 | { | |
144 | struct nic7018_wdt *wdt = watchdog_get_drvdata(wdd); | |
145 | u8 count; | |
146 | ||
147 | count = inb(wdt->io_base + WDT_COUNT) & 0xF; | |
148 | if (!count) | |
149 | return 0; | |
150 | ||
151 | return nic7018_timeout(wdt->period, count); | |
152 | } | |
153 | ||
154 | static const struct watchdog_info nic7018_wdd_info = { | |
155 | .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE, | |
156 | .identity = "NIC7018 Watchdog", | |
157 | }; | |
158 | ||
159 | static const struct watchdog_ops nic7018_wdd_ops = { | |
160 | .owner = THIS_MODULE, | |
161 | .start = nic7018_start, | |
162 | .stop = nic7018_stop, | |
163 | .ping = nic7018_ping, | |
164 | .set_timeout = nic7018_set_timeout, | |
165 | .get_timeleft = nic7018_get_timeleft, | |
166 | }; | |
167 | ||
168 | static int nic7018_probe(struct platform_device *pdev) | |
169 | { | |
170 | struct device *dev = &pdev->dev; | |
171 | struct watchdog_device *wdd; | |
172 | struct nic7018_wdt *wdt; | |
173 | struct resource *io_rc; | |
174 | int ret; | |
175 | ||
176 | wdt = devm_kzalloc(dev, sizeof(*wdt), GFP_KERNEL); | |
177 | if (!wdt) | |
178 | return -ENOMEM; | |
179 | ||
180 | platform_set_drvdata(pdev, wdt); | |
181 | ||
182 | io_rc = platform_get_resource(pdev, IORESOURCE_IO, 0); | |
183 | if (!io_rc) { | |
184 | dev_err(dev, "missing IO resources\n"); | |
185 | return -EINVAL; | |
186 | } | |
187 | ||
188 | if (!devm_request_region(dev, io_rc->start, resource_size(io_rc), | |
189 | KBUILD_MODNAME)) { | |
190 | dev_err(dev, "failed to get IO region\n"); | |
191 | return -EBUSY; | |
192 | } | |
193 | ||
194 | wdt->io_base = io_rc->start; | |
195 | wdd = &wdt->wdd; | |
196 | wdd->info = &nic7018_wdd_info; | |
197 | wdd->ops = &nic7018_wdd_ops; | |
198 | wdd->min_timeout = WDT_MIN_TIMEOUT; | |
199 | wdd->max_timeout = WDT_MAX_TIMEOUT; | |
200 | wdd->timeout = WDT_DEFAULT_TIMEOUT; | |
201 | wdd->parent = dev; | |
202 | ||
203 | watchdog_set_drvdata(wdd, wdt); | |
204 | watchdog_set_nowayout(wdd, nowayout); | |
14fad5d9 | 205 | watchdog_init_timeout(wdd, timeout, dev); |
98078ca3 HCO |
206 | |
207 | /* Unlock WDT register */ | |
208 | outb(UNLOCK, wdt->io_base + WDT_REG_LOCK); | |
209 | ||
210 | ret = watchdog_register_device(wdd); | |
211 | if (ret) { | |
212 | outb(LOCK, wdt->io_base + WDT_REG_LOCK); | |
98078ca3 HCO |
213 | return ret; |
214 | } | |
215 | ||
216 | dev_dbg(dev, "io_base=0x%04X, timeout=%d, nowayout=%d\n", | |
217 | wdt->io_base, timeout, nowayout); | |
218 | return 0; | |
219 | } | |
220 | ||
55b0fb45 | 221 | static void nic7018_remove(struct platform_device *pdev) |
98078ca3 HCO |
222 | { |
223 | struct nic7018_wdt *wdt = platform_get_drvdata(pdev); | |
224 | ||
225 | watchdog_unregister_device(&wdt->wdd); | |
226 | ||
227 | /* Lock WDT register */ | |
228 | outb(LOCK, wdt->io_base + WDT_REG_LOCK); | |
98078ca3 HCO |
229 | } |
230 | ||
231 | static const struct acpi_device_id nic7018_device_ids[] = { | |
232 | {"NIC7018", 0}, | |
233 | {"", 0}, | |
234 | }; | |
235 | MODULE_DEVICE_TABLE(acpi, nic7018_device_ids); | |
236 | ||
237 | static struct platform_driver watchdog_driver = { | |
238 | .probe = nic7018_probe, | |
55b0fb45 | 239 | .remove_new = nic7018_remove, |
98078ca3 HCO |
240 | .driver = { |
241 | .name = KBUILD_MODNAME, | |
242 | .acpi_match_table = ACPI_PTR(nic7018_device_ids), | |
243 | }, | |
244 | }; | |
245 | ||
246 | module_platform_driver(watchdog_driver); | |
247 | ||
248 | MODULE_DESCRIPTION("National Instruments NIC7018 Watchdog driver"); | |
249 | MODULE_AUTHOR("Hui Chun Ong <hui.chun.ong@ni.com>"); | |
250 | MODULE_LICENSE("GPL"); |