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/device.h>
8 #include <linux/interrupt.h>
9 #include <linux/io.h>
10 #include <linux/module.h>
11 #include <linux/watchdog.h>
12
13 #define NIWD_CONTROL 0x01
14 #define NIWD_COUNTER2 0x02
15 #define NIWD_COUNTER1 0x03
16 #define NIWD_COUNTER0 0x04
17 #define NIWD_SEED2 0x05
18 #define NIWD_SEED1 0x06
19 #define NIWD_SEED0 0x07
20
21 #define NIWD_IO_SIZE 0x08
22
23 #define NIWD_CONTROL_MODE 0x80
24 #define NIWD_CONTROL_PROC_RESET 0x20
25 #define NIWD_CONTROL_PET 0x10
26 #define NIWD_CONTROL_RUNNING 0x08
27 #define NIWD_CONTROL_CAPTURECOUNTER 0x04
28 #define NIWD_CONTROL_RESET 0x02
29 #define NIWD_CONTROL_ALARM 0x01
30
31 #define NIWD_PERIOD_NS 30720
32 #define NIWD_MIN_TIMEOUT 1
33 #define NIWD_MAX_TIMEOUT 515
34 #define NIWD_DEFAULT_TIMEOUT 60
35
36 #define NIWD_NAME "ni903x_wdt"
37
38 struct ni903x_wdt {
39 struct device *dev;
40 u16 io_base;
41 struct watchdog_device wdd;
42 };
43
44 static unsigned int timeout;
45 module_param(timeout, uint, 0);
46 MODULE_PARM_DESC(timeout,
47 "Watchdog timeout in seconds. (default="
48 __MODULE_STRING(NIWD_DEFAULT_TIMEOUT) ")");
49
50 static int nowayout = WATCHDOG_NOWAYOUT;
51 module_param(nowayout, int, S_IRUGO);
52 MODULE_PARM_DESC(nowayout,
53 "Watchdog cannot be stopped once started (default="
54 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
55
ni903x_start(struct ni903x_wdt * wdt)56 static void ni903x_start(struct ni903x_wdt *wdt)
57 {
58 u8 control = inb(wdt->io_base + NIWD_CONTROL);
59
60 outb(control | NIWD_CONTROL_RESET, wdt->io_base + NIWD_CONTROL);
61 outb(control | NIWD_CONTROL_PET, wdt->io_base + NIWD_CONTROL);
62 }
63
ni903x_wdd_set_timeout(struct watchdog_device * wdd,unsigned int timeout)64 static int ni903x_wdd_set_timeout(struct watchdog_device *wdd,
65 unsigned int timeout)
66 {
67 struct ni903x_wdt *wdt = watchdog_get_drvdata(wdd);
68 u32 counter = timeout * (1000000000 / NIWD_PERIOD_NS);
69
70 outb(((0x00FF0000 & counter) >> 16), wdt->io_base + NIWD_SEED2);
71 outb(((0x0000FF00 & counter) >> 8), wdt->io_base + NIWD_SEED1);
72 outb((0x000000FF & counter), wdt->io_base + NIWD_SEED0);
73
74 wdd->timeout = timeout;
75
76 return 0;
77 }
78
ni903x_wdd_get_timeleft(struct watchdog_device * wdd)79 static unsigned int ni903x_wdd_get_timeleft(struct watchdog_device *wdd)
80 {
81 struct ni903x_wdt *wdt = watchdog_get_drvdata(wdd);
82 u8 control, counter0, counter1, counter2;
83 u32 counter;
84
85 control = inb(wdt->io_base + NIWD_CONTROL);
86 control |= NIWD_CONTROL_CAPTURECOUNTER;
87 outb(control, wdt->io_base + NIWD_CONTROL);
88
89 counter2 = inb(wdt->io_base + NIWD_COUNTER2);
90 counter1 = inb(wdt->io_base + NIWD_COUNTER1);
91 counter0 = inb(wdt->io_base + NIWD_COUNTER0);
92
93 counter = (counter2 << 16) | (counter1 << 8) | counter0;
94
95 return counter / (1000000000 / NIWD_PERIOD_NS);
96 }
97
ni903x_wdd_ping(struct watchdog_device * wdd)98 static int ni903x_wdd_ping(struct watchdog_device *wdd)
99 {
100 struct ni903x_wdt *wdt = watchdog_get_drvdata(wdd);
101 u8 control;
102
103 control = inb(wdt->io_base + NIWD_CONTROL);
104 outb(control | NIWD_CONTROL_PET, wdt->io_base + NIWD_CONTROL);
105
106 return 0;
107 }
108
ni903x_wdd_start(struct watchdog_device * wdd)109 static int ni903x_wdd_start(struct watchdog_device *wdd)
110 {
111 struct ni903x_wdt *wdt = watchdog_get_drvdata(wdd);
112
113 outb(NIWD_CONTROL_RESET | NIWD_CONTROL_PROC_RESET,
114 wdt->io_base + NIWD_CONTROL);
115
116 ni903x_wdd_set_timeout(wdd, wdd->timeout);
117 ni903x_start(wdt);
118
119 return 0;
120 }
121
ni903x_wdd_stop(struct watchdog_device * wdd)122 static int ni903x_wdd_stop(struct watchdog_device *wdd)
123 {
124 struct ni903x_wdt *wdt = watchdog_get_drvdata(wdd);
125
126 outb(NIWD_CONTROL_RESET, wdt->io_base + NIWD_CONTROL);
127
128 return 0;
129 }
130
ni903x_resources(struct acpi_resource * res,void * data)131 static acpi_status ni903x_resources(struct acpi_resource *res, void *data)
132 {
133 struct ni903x_wdt *wdt = data;
134 u16 io_size;
135
136 switch (res->type) {
137 case ACPI_RESOURCE_TYPE_IO:
138 if (wdt->io_base != 0) {
139 dev_err(wdt->dev, "too many IO resources\n");
140 return AE_ERROR;
141 }
142
143 wdt->io_base = res->data.io.minimum;
144 io_size = res->data.io.address_length;
145
146 if (io_size < NIWD_IO_SIZE) {
147 dev_err(wdt->dev, "memory region too small\n");
148 return AE_ERROR;
149 }
150
151 if (!devm_request_region(wdt->dev, wdt->io_base, io_size,
152 NIWD_NAME)) {
153 dev_err(wdt->dev, "failed to get memory region\n");
154 return AE_ERROR;
155 }
156
157 return AE_OK;
158
159 case ACPI_RESOURCE_TYPE_END_TAG:
160 default:
161 /* Ignore unsupported resources, e.g. IRQ */
162 return AE_OK;
163 }
164 }
165
166 static const struct watchdog_info ni903x_wdd_info = {
167 .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
168 .identity = "NI Watchdog",
169 };
170
171 static const struct watchdog_ops ni903x_wdd_ops = {
172 .owner = THIS_MODULE,
173 .start = ni903x_wdd_start,
174 .stop = ni903x_wdd_stop,
175 .ping = ni903x_wdd_ping,
176 .set_timeout = ni903x_wdd_set_timeout,
177 .get_timeleft = ni903x_wdd_get_timeleft,
178 };
179
ni903x_acpi_add(struct acpi_device * device)180 static int ni903x_acpi_add(struct acpi_device *device)
181 {
182 struct device *dev = &device->dev;
183 struct watchdog_device *wdd;
184 struct ni903x_wdt *wdt;
185 acpi_status status;
186 int ret;
187
188 wdt = devm_kzalloc(dev, sizeof(*wdt), GFP_KERNEL);
189 if (!wdt)
190 return -ENOMEM;
191
192 device->driver_data = wdt;
193 wdt->dev = dev;
194
195 status = acpi_walk_resources(device->handle, METHOD_NAME__CRS,
196 ni903x_resources, wdt);
197 if (ACPI_FAILURE(status) || wdt->io_base == 0) {
198 dev_err(dev, "failed to get resources\n");
199 return -ENODEV;
200 }
201
202 wdd = &wdt->wdd;
203 wdd->info = &ni903x_wdd_info;
204 wdd->ops = &ni903x_wdd_ops;
205 wdd->min_timeout = NIWD_MIN_TIMEOUT;
206 wdd->max_timeout = NIWD_MAX_TIMEOUT;
207 wdd->timeout = NIWD_DEFAULT_TIMEOUT;
208 wdd->parent = dev;
209 watchdog_set_drvdata(wdd, wdt);
210 watchdog_set_nowayout(wdd, nowayout);
211 watchdog_init_timeout(wdd, timeout, dev);
212
213 ret = watchdog_register_device(wdd);
214 if (ret)
215 return ret;
216
217 /* Switch from boot mode to user mode */
218 outb(NIWD_CONTROL_RESET | NIWD_CONTROL_MODE,
219 wdt->io_base + NIWD_CONTROL);
220
221 dev_dbg(dev, "io_base=0x%04X, timeout=%d, nowayout=%d\n",
222 wdt->io_base, timeout, nowayout);
223
224 return 0;
225 }
226
ni903x_acpi_remove(struct acpi_device * device)227 static void ni903x_acpi_remove(struct acpi_device *device)
228 {
229 struct ni903x_wdt *wdt = acpi_driver_data(device);
230
231 ni903x_wdd_stop(&wdt->wdd);
232 watchdog_unregister_device(&wdt->wdd);
233 }
234
235 static const struct acpi_device_id ni903x_device_ids[] = {
236 {"NIC775C", 0},
237 {"", 0},
238 };
239 MODULE_DEVICE_TABLE(acpi, ni903x_device_ids);
240
241 static struct acpi_driver ni903x_acpi_driver = {
242 .name = NIWD_NAME,
243 .ids = ni903x_device_ids,
244 .ops = {
245 .add = ni903x_acpi_add,
246 .remove = ni903x_acpi_remove,
247 },
248 };
249
250 module_acpi_driver(ni903x_acpi_driver);
251
252 MODULE_DESCRIPTION("NI 903x Watchdog");
253 MODULE_AUTHOR("Jeff Westfahl <jeff.westfahl@ni.com>");
254 MODULE_AUTHOR("Kyle Roeschley <kyle.roeschley@ni.com>");
255 MODULE_LICENSE("GPL");
256