GNU Linux-libre 4.9.328-gnu1
[releases.git] / drivers / watchdog / ni903x_wdt.c
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/device.h>
17 #include <linux/interrupt.h>
18 #include <linux/io.h>
19 #include <linux/module.h>
20 #include <linux/watchdog.h>
21
22 #define NIWD_CONTROL    0x01
23 #define NIWD_COUNTER2   0x02
24 #define NIWD_COUNTER1   0x03
25 #define NIWD_COUNTER0   0x04
26 #define NIWD_SEED2      0x05
27 #define NIWD_SEED1      0x06
28 #define NIWD_SEED0      0x07
29
30 #define NIWD_IO_SIZE    0x08
31
32 #define NIWD_CONTROL_MODE               0x80
33 #define NIWD_CONTROL_PROC_RESET         0x20
34 #define NIWD_CONTROL_PET                0x10
35 #define NIWD_CONTROL_RUNNING            0x08
36 #define NIWD_CONTROL_CAPTURECOUNTER     0x04
37 #define NIWD_CONTROL_RESET              0x02
38 #define NIWD_CONTROL_ALARM              0x01
39
40 #define NIWD_PERIOD_NS          30720
41 #define NIWD_MIN_TIMEOUT        1
42 #define NIWD_MAX_TIMEOUT        515
43 #define NIWD_DEFAULT_TIMEOUT    60
44
45 #define NIWD_NAME               "ni903x_wdt"
46
47 struct ni903x_wdt {
48         struct device *dev;
49         u16 io_base;
50         struct watchdog_device wdd;
51 };
52
53 static unsigned int timeout;
54 module_param(timeout, uint, 0);
55 MODULE_PARM_DESC(timeout,
56                  "Watchdog timeout in seconds. (default="
57                  __MODULE_STRING(NIWD_DEFAULT_TIMEOUT) ")");
58
59 static int nowayout = WATCHDOG_NOWAYOUT;
60 module_param(nowayout, int, S_IRUGO);
61 MODULE_PARM_DESC(nowayout,
62                  "Watchdog cannot be stopped once started (default="
63                  __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
64
65 static void ni903x_start(struct ni903x_wdt *wdt)
66 {
67         u8 control = inb(wdt->io_base + NIWD_CONTROL);
68
69         outb(control | NIWD_CONTROL_RESET, wdt->io_base + NIWD_CONTROL);
70         outb(control | NIWD_CONTROL_PET, wdt->io_base + NIWD_CONTROL);
71 }
72
73 static int ni903x_wdd_set_timeout(struct watchdog_device *wdd,
74                                   unsigned int timeout)
75 {
76         struct ni903x_wdt *wdt = watchdog_get_drvdata(wdd);
77         u32 counter = timeout * (1000000000 / NIWD_PERIOD_NS);
78
79         outb(((0x00FF0000 & counter) >> 16), wdt->io_base + NIWD_SEED2);
80         outb(((0x0000FF00 & counter) >> 8), wdt->io_base + NIWD_SEED1);
81         outb((0x000000FF & counter), wdt->io_base + NIWD_SEED0);
82
83         wdd->timeout = timeout;
84
85         return 0;
86 }
87
88 static unsigned int ni903x_wdd_get_timeleft(struct watchdog_device *wdd)
89 {
90         struct ni903x_wdt *wdt = watchdog_get_drvdata(wdd);
91         u8 control, counter0, counter1, counter2;
92         u32 counter;
93
94         control = inb(wdt->io_base + NIWD_CONTROL);
95         control |= NIWD_CONTROL_CAPTURECOUNTER;
96         outb(control, wdt->io_base + NIWD_CONTROL);
97
98         counter2 = inb(wdt->io_base + NIWD_COUNTER2);
99         counter1 = inb(wdt->io_base + NIWD_COUNTER1);
100         counter0 = inb(wdt->io_base + NIWD_COUNTER0);
101
102         counter = (counter2 << 16) | (counter1 << 8) | counter0;
103
104         return counter / (1000000000 / NIWD_PERIOD_NS);
105 }
106
107 static int ni903x_wdd_ping(struct watchdog_device *wdd)
108 {
109         struct ni903x_wdt *wdt = watchdog_get_drvdata(wdd);
110         u8 control;
111
112         control = inb(wdt->io_base + NIWD_CONTROL);
113         outb(control | NIWD_CONTROL_PET, wdt->io_base + NIWD_CONTROL);
114
115         return 0;
116 }
117
118 static int ni903x_wdd_start(struct watchdog_device *wdd)
119 {
120         struct ni903x_wdt *wdt = watchdog_get_drvdata(wdd);
121
122         outb(NIWD_CONTROL_RESET | NIWD_CONTROL_PROC_RESET,
123              wdt->io_base + NIWD_CONTROL);
124
125         ni903x_wdd_set_timeout(wdd, wdd->timeout);
126         ni903x_start(wdt);
127
128         return 0;
129 }
130
131 static int ni903x_wdd_stop(struct watchdog_device *wdd)
132 {
133         struct ni903x_wdt *wdt = watchdog_get_drvdata(wdd);
134
135         outb(NIWD_CONTROL_RESET, wdt->io_base + NIWD_CONTROL);
136
137         return 0;
138 }
139
140 static acpi_status ni903x_resources(struct acpi_resource *res, void *data)
141 {
142         struct ni903x_wdt *wdt = data;
143         u16 io_size;
144
145         switch (res->type) {
146         case ACPI_RESOURCE_TYPE_IO:
147                 if (wdt->io_base != 0) {
148                         dev_err(wdt->dev, "too many IO resources\n");
149                         return AE_ERROR;
150                 }
151
152                 wdt->io_base = res->data.io.minimum;
153                 io_size = res->data.io.address_length;
154
155                 if (io_size < NIWD_IO_SIZE) {
156                         dev_err(wdt->dev, "memory region too small\n");
157                         return AE_ERROR;
158                 }
159
160                 if (!devm_request_region(wdt->dev, wdt->io_base, io_size,
161                                          NIWD_NAME)) {
162                         dev_err(wdt->dev, "failed to get memory region\n");
163                         return AE_ERROR;
164                 }
165
166                 return AE_OK;
167
168         case ACPI_RESOURCE_TYPE_END_TAG:
169         default:
170                 /* Ignore unsupported resources, e.g. IRQ */
171                 return AE_OK;
172         }
173 }
174
175 static const struct watchdog_info ni903x_wdd_info = {
176         .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
177         .identity = "NI Watchdog",
178 };
179
180 static const struct watchdog_ops ni903x_wdd_ops = {
181         .owner = THIS_MODULE,
182         .start = ni903x_wdd_start,
183         .stop = ni903x_wdd_stop,
184         .ping = ni903x_wdd_ping,
185         .set_timeout = ni903x_wdd_set_timeout,
186         .get_timeleft = ni903x_wdd_get_timeleft,
187 };
188
189 static int ni903x_acpi_add(struct acpi_device *device)
190 {
191         struct device *dev = &device->dev;
192         struct watchdog_device *wdd;
193         struct ni903x_wdt *wdt;
194         acpi_status status;
195         int ret;
196
197         wdt = devm_kzalloc(dev, sizeof(*wdt), GFP_KERNEL);
198         if (!wdt)
199                 return -ENOMEM;
200
201         device->driver_data = wdt;
202         wdt->dev = dev;
203
204         status = acpi_walk_resources(device->handle, METHOD_NAME__CRS,
205                                      ni903x_resources, wdt);
206         if (ACPI_FAILURE(status) || wdt->io_base == 0) {
207                 dev_err(dev, "failed to get resources\n");
208                 return -ENODEV;
209         }
210
211         wdd = &wdt->wdd;
212         wdd->info = &ni903x_wdd_info;
213         wdd->ops = &ni903x_wdd_ops;
214         wdd->min_timeout = NIWD_MIN_TIMEOUT;
215         wdd->max_timeout = NIWD_MAX_TIMEOUT;
216         wdd->timeout = NIWD_DEFAULT_TIMEOUT;
217         wdd->parent = dev;
218         watchdog_set_drvdata(wdd, wdt);
219         watchdog_set_nowayout(wdd, nowayout);
220         ret = watchdog_init_timeout(wdd, timeout, dev);
221         if (ret)
222                 dev_err(dev, "unable to set timeout value, using default\n");
223
224         ret = watchdog_register_device(wdd);
225         if (ret) {
226                 dev_err(dev, "failed to register watchdog\n");
227                 return ret;
228         }
229
230         /* Switch from boot mode to user mode */
231         outb(NIWD_CONTROL_RESET | NIWD_CONTROL_MODE,
232              wdt->io_base + NIWD_CONTROL);
233
234         dev_dbg(dev, "io_base=0x%04X, timeout=%d, nowayout=%d\n",
235                 wdt->io_base, timeout, nowayout);
236
237         return 0;
238 }
239
240 static int ni903x_acpi_remove(struct acpi_device *device)
241 {
242         struct ni903x_wdt *wdt = acpi_driver_data(device);
243
244         ni903x_wdd_stop(&wdt->wdd);
245         watchdog_unregister_device(&wdt->wdd);
246
247         return 0;
248 }
249
250 static const struct acpi_device_id ni903x_device_ids[] = {
251         {"NIC775C", 0},
252         {"", 0},
253 };
254 MODULE_DEVICE_TABLE(acpi, ni903x_device_ids);
255
256 static struct acpi_driver ni903x_acpi_driver = {
257         .name = NIWD_NAME,
258         .ids = ni903x_device_ids,
259         .ops = {
260                 .add = ni903x_acpi_add,
261                 .remove = ni903x_acpi_remove,
262         },
263 };
264
265 module_acpi_driver(ni903x_acpi_driver);
266
267 MODULE_DESCRIPTION("NI 903x Watchdog");
268 MODULE_AUTHOR("Jeff Westfahl <jeff.westfahl@ni.com>");
269 MODULE_AUTHOR("Kyle Roeschley <kyle.roeschley@ni.com>");
270 MODULE_LICENSE("GPL");