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24#include <linux/module.h>
25#include <linux/moduleparam.h>
26#include <linux/platform_device.h>
27#include <linux/io.h>
28#include <linux/kernel.h>
29#include <linux/types.h>
30#include <linux/watchdog.h>
31#include <linux/miscdevice.h>
32#include <linux/seq_file.h>
33#include <linux/debugfs.h>
34#include <linux/uaccess.h>
35#include <linux/spinlock.h>
36
37#define DRIVER_NAME "ie6xx_wdt"
38
39#define PV1 0x00
40#define PV2 0x04
41
42#define RR0 0x0c
43#define RR1 0x0d
44#define WDT_RELOAD 0x01
45#define WDT_TOUT 0x02
46
47#define WDTCR 0x10
48#define WDT_PRE_SEL 0x04
49#define WDT_RESET_SEL 0x08
50#define WDT_RESET_EN 0x10
51#define WDT_TOUT_EN 0x20
52
53#define DCR 0x14
54
55#define WDTLR 0x18
56#define WDT_LOCK 0x01
57#define WDT_ENABLE 0x02
58#define WDT_TOUT_CNF 0x03
59
60#define MIN_TIME 1
61#define MAX_TIME (10 * 60)
62#define DEFAULT_TIME 60
63
64static unsigned int timeout = DEFAULT_TIME;
65module_param(timeout, uint, 0);
66MODULE_PARM_DESC(timeout,
67 "Default Watchdog timer setting ("
68 __MODULE_STRING(DEFAULT_TIME) "s)."
69 "The range is from 1 to 600");
70
71static bool nowayout = WATCHDOG_NOWAYOUT;
72module_param(nowayout, bool, 0);
73MODULE_PARM_DESC(nowayout,
74 "Watchdog cannot be stopped once started (default="
75 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
76
77static u8 resetmode = 0x10;
78module_param(resetmode, byte, 0);
79MODULE_PARM_DESC(resetmode,
80 "Resetmode bits: 0x08 warm reset (cold reset otherwise), "
81 "0x10 reset enable, 0x20 disable toggle GPIO[4] (default=0x10)");
82
83static struct {
84 unsigned short sch_wdtba;
85 struct spinlock unlock_sequence;
86#ifdef CONFIG_DEBUG_FS
87 struct dentry *debugfs;
88#endif
89} ie6xx_wdt_data;
90
91
92
93
94
95
96static void ie6xx_wdt_unlock_registers(void)
97{
98 outb(0x80, ie6xx_wdt_data.sch_wdtba + RR0);
99 outb(0x86, ie6xx_wdt_data.sch_wdtba + RR0);
100}
101
102static int ie6xx_wdt_ping(struct watchdog_device *wdd)
103{
104 spin_lock(&ie6xx_wdt_data.unlock_sequence);
105 ie6xx_wdt_unlock_registers();
106 outb(WDT_RELOAD, ie6xx_wdt_data.sch_wdtba + RR1);
107 spin_unlock(&ie6xx_wdt_data.unlock_sequence);
108 return 0;
109}
110
111static int ie6xx_wdt_set_timeout(struct watchdog_device *wdd, unsigned int t)
112{
113 u32 preload;
114 u64 clock;
115 u8 wdtcr;
116
117
118 clock = 33000000;
119
120 preload = (t * clock) >> 15;
121
122
123
124
125 preload -= 1;
126
127 spin_lock(&ie6xx_wdt_data.unlock_sequence);
128
129
130 wdtcr = resetmode & 0x38;
131 outb(wdtcr, ie6xx_wdt_data.sch_wdtba + WDTCR);
132
133 ie6xx_wdt_unlock_registers();
134 outl(0, ie6xx_wdt_data.sch_wdtba + PV1);
135
136 ie6xx_wdt_unlock_registers();
137 outl(preload, ie6xx_wdt_data.sch_wdtba + PV2);
138
139 ie6xx_wdt_unlock_registers();
140 outb(WDT_RELOAD | WDT_TOUT, ie6xx_wdt_data.sch_wdtba + RR1);
141
142 spin_unlock(&ie6xx_wdt_data.unlock_sequence);
143
144 wdd->timeout = t;
145 return 0;
146}
147
148static int ie6xx_wdt_start(struct watchdog_device *wdd)
149{
150 ie6xx_wdt_set_timeout(wdd, wdd->timeout);
151
152
153 spin_lock(&ie6xx_wdt_data.unlock_sequence);
154 outb(WDT_ENABLE, ie6xx_wdt_data.sch_wdtba + WDTLR);
155 spin_unlock(&ie6xx_wdt_data.unlock_sequence);
156
157 return 0;
158}
159
160static int ie6xx_wdt_stop(struct watchdog_device *wdd)
161{
162 if (inb(ie6xx_wdt_data.sch_wdtba + WDTLR) & WDT_LOCK)
163 return -1;
164
165
166 spin_lock(&ie6xx_wdt_data.unlock_sequence);
167 outb(0, ie6xx_wdt_data.sch_wdtba + WDTLR);
168 spin_unlock(&ie6xx_wdt_data.unlock_sequence);
169
170 return 0;
171}
172
173static const struct watchdog_info ie6xx_wdt_info = {
174 .identity = "Intel Atom E6xx Watchdog",
175 .options = WDIOF_SETTIMEOUT |
176 WDIOF_MAGICCLOSE |
177 WDIOF_KEEPALIVEPING,
178};
179
180static const struct watchdog_ops ie6xx_wdt_ops = {
181 .owner = THIS_MODULE,
182 .start = ie6xx_wdt_start,
183 .stop = ie6xx_wdt_stop,
184 .ping = ie6xx_wdt_ping,
185 .set_timeout = ie6xx_wdt_set_timeout,
186};
187
188static struct watchdog_device ie6xx_wdt_dev = {
189 .info = &ie6xx_wdt_info,
190 .ops = &ie6xx_wdt_ops,
191 .min_timeout = MIN_TIME,
192 .max_timeout = MAX_TIME,
193};
194
195#ifdef CONFIG_DEBUG_FS
196
197static int ie6xx_wdt_dbg_show(struct seq_file *s, void *unused)
198{
199 seq_printf(s, "PV1 = 0x%08x\n",
200 inl(ie6xx_wdt_data.sch_wdtba + PV1));
201 seq_printf(s, "PV2 = 0x%08x\n",
202 inl(ie6xx_wdt_data.sch_wdtba + PV2));
203 seq_printf(s, "RR = 0x%08x\n",
204 inw(ie6xx_wdt_data.sch_wdtba + RR0));
205 seq_printf(s, "WDTCR = 0x%08x\n",
206 inw(ie6xx_wdt_data.sch_wdtba + WDTCR));
207 seq_printf(s, "DCR = 0x%08x\n",
208 inl(ie6xx_wdt_data.sch_wdtba + DCR));
209 seq_printf(s, "WDTLR = 0x%08x\n",
210 inw(ie6xx_wdt_data.sch_wdtba + WDTLR));
211
212 seq_printf(s, "\n");
213 return 0;
214}
215
216static int ie6xx_wdt_dbg_open(struct inode *inode, struct file *file)
217{
218 return single_open(file, ie6xx_wdt_dbg_show, NULL);
219}
220
221static const struct file_operations ie6xx_wdt_dbg_operations = {
222 .open = ie6xx_wdt_dbg_open,
223 .read = seq_read,
224 .llseek = seq_lseek,
225 .release = single_release,
226};
227
228static void ie6xx_wdt_debugfs_init(void)
229{
230
231 ie6xx_wdt_data.debugfs = debugfs_create_file("ie6xx_wdt",
232 S_IFREG | S_IRUGO, NULL, NULL, &ie6xx_wdt_dbg_operations);
233}
234
235static void ie6xx_wdt_debugfs_exit(void)
236{
237 debugfs_remove(ie6xx_wdt_data.debugfs);
238}
239
240#else
241static void ie6xx_wdt_debugfs_init(void)
242{
243}
244
245static void ie6xx_wdt_debugfs_exit(void)
246{
247}
248#endif
249
250static int ie6xx_wdt_probe(struct platform_device *pdev)
251{
252 struct resource *res;
253 u8 wdtlr;
254 int ret;
255
256 res = platform_get_resource(pdev, IORESOURCE_IO, 0);
257 if (!res)
258 return -ENODEV;
259
260 if (!request_region(res->start, resource_size(res), pdev->name)) {
261 dev_err(&pdev->dev, "Watchdog region 0x%llx already in use!\n",
262 (u64)res->start);
263 return -EBUSY;
264 }
265
266 ie6xx_wdt_data.sch_wdtba = res->start;
267 dev_dbg(&pdev->dev, "WDT = 0x%X\n", ie6xx_wdt_data.sch_wdtba);
268
269 ie6xx_wdt_dev.timeout = timeout;
270 watchdog_set_nowayout(&ie6xx_wdt_dev, nowayout);
271
272 spin_lock_init(&ie6xx_wdt_data.unlock_sequence);
273
274 wdtlr = inb(ie6xx_wdt_data.sch_wdtba + WDTLR);
275 if (wdtlr & WDT_LOCK)
276 dev_warn(&pdev->dev,
277 "Watchdog Timer is Locked (Reg=0x%x)\n", wdtlr);
278
279 ie6xx_wdt_debugfs_init();
280
281 ret = watchdog_register_device(&ie6xx_wdt_dev);
282 if (ret) {
283 dev_err(&pdev->dev,
284 "Watchdog timer: cannot register device (err =%d)\n",
285 ret);
286 goto misc_register_error;
287 }
288
289 return 0;
290
291misc_register_error:
292 ie6xx_wdt_debugfs_exit();
293 release_region(res->start, resource_size(res));
294 ie6xx_wdt_data.sch_wdtba = 0;
295 return ret;
296}
297
298static int ie6xx_wdt_remove(struct platform_device *pdev)
299{
300 struct resource *res;
301
302 res = platform_get_resource(pdev, IORESOURCE_IO, 0);
303 ie6xx_wdt_stop(NULL);
304 watchdog_unregister_device(&ie6xx_wdt_dev);
305 ie6xx_wdt_debugfs_exit();
306 release_region(res->start, resource_size(res));
307 ie6xx_wdt_data.sch_wdtba = 0;
308
309 return 0;
310}
311
312static struct platform_driver ie6xx_wdt_driver = {
313 .probe = ie6xx_wdt_probe,
314 .remove = ie6xx_wdt_remove,
315 .driver = {
316 .name = DRIVER_NAME,
317 .owner = THIS_MODULE,
318 },
319};
320
321static int __init ie6xx_wdt_init(void)
322{
323
324
325 if ((timeout < MIN_TIME) ||
326 (timeout > MAX_TIME)) {
327 pr_err("Watchdog timer: value of timeout %d (dec) "
328 "is out of range from %d to %d (dec)\n",
329 timeout, MIN_TIME, MAX_TIME);
330 return -EINVAL;
331 }
332
333 return platform_driver_register(&ie6xx_wdt_driver);
334}
335
336static void __exit ie6xx_wdt_exit(void)
337{
338 platform_driver_unregister(&ie6xx_wdt_driver);
339}
340
341late_initcall(ie6xx_wdt_init);
342module_exit(ie6xx_wdt_exit);
343
344MODULE_AUTHOR("Alexander Stein <alexander.stein@systec-electronic.com>");
345MODULE_DESCRIPTION("Intel Atom E6xx Watchdog Device Driver");
346MODULE_LICENSE("GPL");
347MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
348MODULE_ALIAS("platform:" DRIVER_NAME);
349
