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 int 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 	return 0;
235 }
236 
237 static const struct acpi_device_id ni903x_device_ids[] = {
238 	{"NIC775C", 0},
239 	{"", 0},
240 };
241 MODULE_DEVICE_TABLE(acpi, ni903x_device_ids);
242 
243 static struct acpi_driver ni903x_acpi_driver = {
244 	.name = NIWD_NAME,
245 	.ids = ni903x_device_ids,
246 	.ops = {
247 		.add = ni903x_acpi_add,
248 		.remove = ni903x_acpi_remove,
249 	},
250 };
251 
252 module_acpi_driver(ni903x_acpi_driver);
253 
254 MODULE_DESCRIPTION("NI 903x Watchdog");
255 MODULE_AUTHOR("Jeff Westfahl <jeff.westfahl@ni.com>");
256 MODULE_AUTHOR("Kyle Roeschley <kyle.roeschley@ni.com>");
257 MODULE_LICENSE("GPL");
258