1 | // SPDX-License-Identifier: GPL-2.0-or-later |
2 | /* |
3 | * Copyright (C) 2016 National Instruments Corp. |
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: &counter); |
94 | |
95 | outb(value: counter << 4 | config->divider, |
96 | port: wdt->io_base + WDT_PRESET_PRESCALE); |
97 | |
98 | wdd->timeout = nic7018_timeout(period: 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, timeout: wdd->timeout); |
110 | |
111 | control = inb(port: wdt->io_base + WDT_RELOAD_CTRL); |
112 | outb(value: control | WDT_RELOAD_PORT_EN, port: wdt->io_base + WDT_RELOAD_CTRL); |
113 | |
114 | outb(value: 1, port: wdt->io_base + WDT_RELOAD_PORT); |
115 | |
116 | control = inb(port: wdt->io_base + WDT_CTRL); |
117 | outb(value: control | WDT_CTRL_RESET_EN, port: 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(value: 0, port: wdt->io_base + WDT_CTRL); |
127 | outb(value: 0, port: wdt->io_base + WDT_RELOAD_CTRL); |
128 | outb(value: 0xF0, port: 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(value: 1, port: 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(port: wdt->io_base + WDT_COUNT) & 0xF; |
148 | if (!count) |
149 | return 0; |
150 | |
151 | return nic7018_timeout(period: wdt->period, counter: 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, size: sizeof(*wdt), GFP_KERNEL); |
177 | if (!wdt) |
178 | return -ENOMEM; |
179 | |
180 | platform_set_drvdata(pdev, data: 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, data: wdt); |
204 | watchdog_set_nowayout(wdd, nowayout); |
205 | watchdog_init_timeout(wdd, timeout_parm: timeout, dev); |
206 | |
207 | /* Unlock WDT register */ |
208 | outb(UNLOCK, port: wdt->io_base + WDT_REG_LOCK); |
209 | |
210 | ret = watchdog_register_device(wdd); |
211 | if (ret) { |
212 | outb(LOCK, port: wdt->io_base + WDT_REG_LOCK); |
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 | |
221 | static void nic7018_remove(struct platform_device *pdev) |
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, port: wdt->io_base + WDT_REG_LOCK); |
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, |
239 | .remove_new = nic7018_remove, |
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" ); |
251 | |