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9#include <linux/module.h>
10#include <linux/moduleparam.h>
11#include <linux/platform_device.h>
12#include <linux/io.h>
13#include <linux/kernel.h>
14#include <linux/types.h>
15#include <linux/watchdog.h>
16#include <linux/seq_file.h>
17#include <linux/debugfs.h>
18#include <linux/uaccess.h>
19#include <linux/spinlock.h>
20
21#define DRIVER_NAME "ie6xx_wdt"
22
23#define PV1 0x00
24#define PV2 0x04
25
26#define RR0 0x0c
27#define RR1 0x0d
28#define WDT_RELOAD 0x01
29#define WDT_TOUT 0x02
30
31#define WDTCR 0x10
32#define WDT_PRE_SEL 0x04
33#define WDT_RESET_SEL 0x08
34#define WDT_RESET_EN 0x10
35#define WDT_TOUT_EN 0x20
36
37#define DCR 0x14
38
39#define WDTLR 0x18
40#define WDT_LOCK 0x01
41#define WDT_ENABLE 0x02
42#define WDT_TOUT_CNF 0x03
43
44#define MIN_TIME 1
45#define MAX_TIME (10 * 60)
46#define DEFAULT_TIME 60
47
48static unsigned int timeout = DEFAULT_TIME;
49module_param(timeout, uint, 0);
50MODULE_PARM_DESC(timeout,
51 "Default Watchdog timer setting ("
52 __MODULE_STRING(DEFAULT_TIME) "s)."
53 "The range is from 1 to 600");
54
55static bool nowayout = WATCHDOG_NOWAYOUT;
56module_param(nowayout, bool, 0);
57MODULE_PARM_DESC(nowayout,
58 "Watchdog cannot be stopped once started (default="
59 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
60
61static u8 resetmode = 0x10;
62module_param(resetmode, byte, 0);
63MODULE_PARM_DESC(resetmode,
64 "Resetmode bits: 0x08 warm reset (cold reset otherwise), "
65 "0x10 reset enable, 0x20 disable toggle GPIO[4] (default=0x10)");
66
67static struct {
68 unsigned short sch_wdtba;
69 spinlock_t unlock_sequence;
70#ifdef CONFIG_DEBUG_FS
71 struct dentry *debugfs;
72#endif
73} ie6xx_wdt_data;
74
75
76
77
78
79
80static void ie6xx_wdt_unlock_registers(void)
81{
82 outb(0x80, ie6xx_wdt_data.sch_wdtba + RR0);
83 outb(0x86, ie6xx_wdt_data.sch_wdtba + RR0);
84}
85
86static int ie6xx_wdt_ping(struct watchdog_device *wdd)
87{
88 spin_lock(&ie6xx_wdt_data.unlock_sequence);
89 ie6xx_wdt_unlock_registers();
90 outb(WDT_RELOAD, ie6xx_wdt_data.sch_wdtba + RR1);
91 spin_unlock(&ie6xx_wdt_data.unlock_sequence);
92 return 0;
93}
94
95static int ie6xx_wdt_set_timeout(struct watchdog_device *wdd, unsigned int t)
96{
97 u32 preload;
98 u64 clock;
99 u8 wdtcr;
100
101
102 clock = 33000000;
103
104 preload = (t * clock) >> 15;
105
106
107
108
109 preload -= 1;
110
111 spin_lock(&ie6xx_wdt_data.unlock_sequence);
112
113
114 wdtcr = resetmode & 0x38;
115 outb(wdtcr, ie6xx_wdt_data.sch_wdtba + WDTCR);
116
117 ie6xx_wdt_unlock_registers();
118 outl(0, ie6xx_wdt_data.sch_wdtba + PV1);
119
120 ie6xx_wdt_unlock_registers();
121 outl(preload, ie6xx_wdt_data.sch_wdtba + PV2);
122
123 ie6xx_wdt_unlock_registers();
124 outb(WDT_RELOAD | WDT_TOUT, ie6xx_wdt_data.sch_wdtba + RR1);
125
126 spin_unlock(&ie6xx_wdt_data.unlock_sequence);
127
128 wdd->timeout = t;
129 return 0;
130}
131
132static int ie6xx_wdt_start(struct watchdog_device *wdd)
133{
134 ie6xx_wdt_set_timeout(wdd, wdd->timeout);
135
136
137 spin_lock(&ie6xx_wdt_data.unlock_sequence);
138 outb(WDT_ENABLE, ie6xx_wdt_data.sch_wdtba + WDTLR);
139 spin_unlock(&ie6xx_wdt_data.unlock_sequence);
140
141 return 0;
142}
143
144static int ie6xx_wdt_stop(struct watchdog_device *wdd)
145{
146 if (inb(ie6xx_wdt_data.sch_wdtba + WDTLR) & WDT_LOCK)
147 return -1;
148
149
150 spin_lock(&ie6xx_wdt_data.unlock_sequence);
151 outb(0, ie6xx_wdt_data.sch_wdtba + WDTLR);
152 spin_unlock(&ie6xx_wdt_data.unlock_sequence);
153
154 return 0;
155}
156
157static const struct watchdog_info ie6xx_wdt_info = {
158 .identity = "Intel Atom E6xx Watchdog",
159 .options = WDIOF_SETTIMEOUT |
160 WDIOF_MAGICCLOSE |
161 WDIOF_KEEPALIVEPING,
162};
163
164static const struct watchdog_ops ie6xx_wdt_ops = {
165 .owner = THIS_MODULE,
166 .start = ie6xx_wdt_start,
167 .stop = ie6xx_wdt_stop,
168 .ping = ie6xx_wdt_ping,
169 .set_timeout = ie6xx_wdt_set_timeout,
170};
171
172static struct watchdog_device ie6xx_wdt_dev = {
173 .info = &ie6xx_wdt_info,
174 .ops = &ie6xx_wdt_ops,
175 .min_timeout = MIN_TIME,
176 .max_timeout = MAX_TIME,
177};
178
179#ifdef CONFIG_DEBUG_FS
180
181static int ie6xx_wdt_show(struct seq_file *s, void *unused)
182{
183 seq_printf(s, "PV1 = 0x%08x\n",
184 inl(ie6xx_wdt_data.sch_wdtba + PV1));
185 seq_printf(s, "PV2 = 0x%08x\n",
186 inl(ie6xx_wdt_data.sch_wdtba + PV2));
187 seq_printf(s, "RR = 0x%08x\n",
188 inw(ie6xx_wdt_data.sch_wdtba + RR0));
189 seq_printf(s, "WDTCR = 0x%08x\n",
190 inw(ie6xx_wdt_data.sch_wdtba + WDTCR));
191 seq_printf(s, "DCR = 0x%08x\n",
192 inl(ie6xx_wdt_data.sch_wdtba + DCR));
193 seq_printf(s, "WDTLR = 0x%08x\n",
194 inw(ie6xx_wdt_data.sch_wdtba + WDTLR));
195
196 seq_printf(s, "\n");
197 return 0;
198}
199
200DEFINE_SHOW_ATTRIBUTE(ie6xx_wdt);
201
202static void ie6xx_wdt_debugfs_init(void)
203{
204
205 ie6xx_wdt_data.debugfs = debugfs_create_file("ie6xx_wdt",
206 S_IFREG | S_IRUGO, NULL, NULL, &ie6xx_wdt_fops);
207}
208
209static void ie6xx_wdt_debugfs_exit(void)
210{
211 debugfs_remove(ie6xx_wdt_data.debugfs);
212}
213
214#else
215static void ie6xx_wdt_debugfs_init(void)
216{
217}
218
219static void ie6xx_wdt_debugfs_exit(void)
220{
221}
222#endif
223
224static int ie6xx_wdt_probe(struct platform_device *pdev)
225{
226 struct resource *res;
227 u8 wdtlr;
228 int ret;
229
230 res = platform_get_resource(pdev, IORESOURCE_IO, 0);
231 if (!res)
232 return -ENODEV;
233
234 if (!request_region(res->start, resource_size(res), pdev->name)) {
235 dev_err(&pdev->dev, "Watchdog region 0x%llx already in use!\n",
236 (u64)res->start);
237 return -EBUSY;
238 }
239
240 ie6xx_wdt_data.sch_wdtba = res->start;
241 dev_dbg(&pdev->dev, "WDT = 0x%X\n", ie6xx_wdt_data.sch_wdtba);
242
243 ie6xx_wdt_dev.timeout = timeout;
244 watchdog_set_nowayout(&ie6xx_wdt_dev, nowayout);
245 ie6xx_wdt_dev.parent = &pdev->dev;
246
247 spin_lock_init(&ie6xx_wdt_data.unlock_sequence);
248
249 wdtlr = inb(ie6xx_wdt_data.sch_wdtba + WDTLR);
250 if (wdtlr & WDT_LOCK)
251 dev_warn(&pdev->dev,
252 "Watchdog Timer is Locked (Reg=0x%x)\n", wdtlr);
253
254 ie6xx_wdt_debugfs_init();
255
256 ret = watchdog_register_device(&ie6xx_wdt_dev);
257 if (ret)
258 goto misc_register_error;
259
260 return 0;
261
262misc_register_error:
263 ie6xx_wdt_debugfs_exit();
264 release_region(res->start, resource_size(res));
265 ie6xx_wdt_data.sch_wdtba = 0;
266 return ret;
267}
268
269static int ie6xx_wdt_remove(struct platform_device *pdev)
270{
271 struct resource *res;
272
273 res = platform_get_resource(pdev, IORESOURCE_IO, 0);
274 ie6xx_wdt_stop(NULL);
275 watchdog_unregister_device(&ie6xx_wdt_dev);
276 ie6xx_wdt_debugfs_exit();
277 release_region(res->start, resource_size(res));
278 ie6xx_wdt_data.sch_wdtba = 0;
279
280 return 0;
281}
282
283static struct platform_driver ie6xx_wdt_driver = {
284 .probe = ie6xx_wdt_probe,
285 .remove = ie6xx_wdt_remove,
286 .driver = {
287 .name = DRIVER_NAME,
288 },
289};
290
291static int __init ie6xx_wdt_init(void)
292{
293
294
295 if ((timeout < MIN_TIME) ||
296 (timeout > MAX_TIME)) {
297 pr_err("Watchdog timer: value of timeout %d (dec) "
298 "is out of range from %d to %d (dec)\n",
299 timeout, MIN_TIME, MAX_TIME);
300 return -EINVAL;
301 }
302
303 return platform_driver_register(&ie6xx_wdt_driver);
304}
305
306static void __exit ie6xx_wdt_exit(void)
307{
308 platform_driver_unregister(&ie6xx_wdt_driver);
309}
310
311late_initcall(ie6xx_wdt_init);
312module_exit(ie6xx_wdt_exit);
313
314MODULE_AUTHOR("Alexander Stein <alexander.stein@systec-electronic.com>");
315MODULE_DESCRIPTION("Intel Atom E6xx Watchdog Device Driver");
316MODULE_LICENSE("GPL");
317MODULE_ALIAS("platform:" DRIVER_NAME);
318
