virtio-mem: simplify high-level unplug handling in Sub Block Mode
[linux-2.6-microblaze.git] / drivers / watchdog / ni903x_wdt.c
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
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
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
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
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
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
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
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
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
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");