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Priyanka Gupta15e28bf2010-10-25 17:58:04 -07001/*
2 * sp5100_tco : TCO timer driver for sp5100 chipsets
3 *
4 * (c) Copyright 2009 Google Inc., All Rights Reserved.
5 *
6 * Based on i8xx_tco.c:
7 * (c) Copyright 2000 kernel concepts <nils@kernelconcepts.de>, All Rights
8 * Reserved.
9 * http://www.kernelconcepts.de
10 *
11 * This program is free software; you can redistribute it and/or
12 * modify it under the terms of the GNU General Public License
13 * as published by the Free Software Foundation; either version
14 * 2 of the License, or (at your option) any later version.
15 *
16 * See AMD Publication 43009 "AMD SB700/710/750 Register Reference Guide"
17 */
18
19/*
20 * Includes, defines, variables, module parameters, ...
21 */
22
Joe Perches27c766a2012-02-15 15:06:19 -080023#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
24
Priyanka Gupta15e28bf2010-10-25 17:58:04 -070025#include <linux/module.h>
26#include <linux/moduleparam.h>
27#include <linux/types.h>
28#include <linux/miscdevice.h>
29#include <linux/watchdog.h>
30#include <linux/init.h>
31#include <linux/fs.h>
32#include <linux/pci.h>
33#include <linux/ioport.h>
34#include <linux/platform_device.h>
35#include <linux/uaccess.h>
36#include <linux/io.h>
37
38#include "sp5100_tco.h"
39
40/* Module and version information */
41#define TCO_VERSION "0.01"
42#define TCO_MODULE_NAME "SP5100 TCO timer"
43#define TCO_DRIVER_NAME TCO_MODULE_NAME ", v" TCO_VERSION
Priyanka Gupta15e28bf2010-10-25 17:58:04 -070044
45/* internal variables */
Yinghai Lu90d241e2011-03-16 20:01:07 -070046static u32 tcobase_phys;
Priyanka Gupta15e28bf2010-10-25 17:58:04 -070047static void __iomem *tcobase;
48static unsigned int pm_iobase;
49static DEFINE_SPINLOCK(tco_lock); /* Guards the hardware */
50static unsigned long timer_alive;
51static char tco_expect_close;
52static struct pci_dev *sp5100_tco_pci;
53
54/* the watchdog platform device */
55static struct platform_device *sp5100_tco_platform_device;
56
57/* module parameters */
58
59#define WATCHDOG_HEARTBEAT 60 /* 60 sec default heartbeat. */
60static int heartbeat = WATCHDOG_HEARTBEAT; /* in seconds */
61module_param(heartbeat, int, 0);
62MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat in seconds. (default="
63 __MODULE_STRING(WATCHDOG_HEARTBEAT) ")");
64
Wim Van Sebroeck86a1e182012-03-05 16:51:11 +010065static bool nowayout = WATCHDOG_NOWAYOUT;
66module_param(nowayout, bool, 0);
Priyanka Gupta15e28bf2010-10-25 17:58:04 -070067MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started"
68 " (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
69
70/*
71 * Some TCO specific functions
72 */
73static void tco_timer_start(void)
74{
75 u32 val;
76 unsigned long flags;
77
78 spin_lock_irqsave(&tco_lock, flags);
79 val = readl(SP5100_WDT_CONTROL(tcobase));
80 val |= SP5100_WDT_START_STOP_BIT;
81 writel(val, SP5100_WDT_CONTROL(tcobase));
82 spin_unlock_irqrestore(&tco_lock, flags);
83}
84
85static void tco_timer_stop(void)
86{
87 u32 val;
88 unsigned long flags;
89
90 spin_lock_irqsave(&tco_lock, flags);
91 val = readl(SP5100_WDT_CONTROL(tcobase));
92 val &= ~SP5100_WDT_START_STOP_BIT;
93 writel(val, SP5100_WDT_CONTROL(tcobase));
94 spin_unlock_irqrestore(&tco_lock, flags);
95}
96
97static void tco_timer_keepalive(void)
98{
99 u32 val;
100 unsigned long flags;
101
102 spin_lock_irqsave(&tco_lock, flags);
103 val = readl(SP5100_WDT_CONTROL(tcobase));
104 val |= SP5100_WDT_TRIGGER_BIT;
105 writel(val, SP5100_WDT_CONTROL(tcobase));
106 spin_unlock_irqrestore(&tco_lock, flags);
107}
108
109static int tco_timer_set_heartbeat(int t)
110{
111 unsigned long flags;
112
113 if (t < 0 || t > 0xffff)
114 return -EINVAL;
115
116 /* Write new heartbeat to watchdog */
117 spin_lock_irqsave(&tco_lock, flags);
118 writel(t, SP5100_WDT_COUNT(tcobase));
119 spin_unlock_irqrestore(&tco_lock, flags);
120
121 heartbeat = t;
122 return 0;
123}
124
125/*
126 * /dev/watchdog handling
127 */
128
129static int sp5100_tco_open(struct inode *inode, struct file *file)
130{
131 /* /dev/watchdog can only be opened once */
132 if (test_and_set_bit(0, &timer_alive))
133 return -EBUSY;
134
135 /* Reload and activate timer */
136 tco_timer_start();
137 tco_timer_keepalive();
138 return nonseekable_open(inode, file);
139}
140
141static int sp5100_tco_release(struct inode *inode, struct file *file)
142{
143 /* Shut off the timer. */
144 if (tco_expect_close == 42) {
145 tco_timer_stop();
146 } else {
Joe Perches27c766a2012-02-15 15:06:19 -0800147 pr_crit("Unexpected close, not stopping watchdog!\n");
Priyanka Gupta15e28bf2010-10-25 17:58:04 -0700148 tco_timer_keepalive();
149 }
150 clear_bit(0, &timer_alive);
151 tco_expect_close = 0;
152 return 0;
153}
154
155static ssize_t sp5100_tco_write(struct file *file, const char __user *data,
156 size_t len, loff_t *ppos)
157{
158 /* See if we got the magic character 'V' and reload the timer */
159 if (len) {
160 if (!nowayout) {
161 size_t i;
162
163 /* note: just in case someone wrote the magic character
164 * five months ago... */
165 tco_expect_close = 0;
166
167 /* scan to see whether or not we got the magic character
168 */
169 for (i = 0; i != len; i++) {
170 char c;
171 if (get_user(c, data + i))
172 return -EFAULT;
173 if (c == 'V')
174 tco_expect_close = 42;
175 }
176 }
177
178 /* someone wrote to us, we should reload the timer */
179 tco_timer_keepalive();
180 }
181 return len;
182}
183
184static long sp5100_tco_ioctl(struct file *file, unsigned int cmd,
185 unsigned long arg)
186{
187 int new_options, retval = -EINVAL;
188 int new_heartbeat;
189 void __user *argp = (void __user *)arg;
190 int __user *p = argp;
191 static const struct watchdog_info ident = {
192 .options = WDIOF_SETTIMEOUT |
193 WDIOF_KEEPALIVEPING |
194 WDIOF_MAGICCLOSE,
195 .firmware_version = 0,
196 .identity = TCO_MODULE_NAME,
197 };
198
199 switch (cmd) {
200 case WDIOC_GETSUPPORT:
201 return copy_to_user(argp, &ident,
202 sizeof(ident)) ? -EFAULT : 0;
203 case WDIOC_GETSTATUS:
204 case WDIOC_GETBOOTSTATUS:
205 return put_user(0, p);
206 case WDIOC_SETOPTIONS:
207 if (get_user(new_options, p))
208 return -EFAULT;
209 if (new_options & WDIOS_DISABLECARD) {
210 tco_timer_stop();
211 retval = 0;
212 }
213 if (new_options & WDIOS_ENABLECARD) {
214 tco_timer_start();
215 tco_timer_keepalive();
216 retval = 0;
217 }
218 return retval;
219 case WDIOC_KEEPALIVE:
220 tco_timer_keepalive();
221 return 0;
222 case WDIOC_SETTIMEOUT:
223 if (get_user(new_heartbeat, p))
224 return -EFAULT;
225 if (tco_timer_set_heartbeat(new_heartbeat))
226 return -EINVAL;
227 tco_timer_keepalive();
228 /* Fall through */
229 case WDIOC_GETTIMEOUT:
230 return put_user(heartbeat, p);
231 default:
232 return -ENOTTY;
233 }
234}
235
236/*
237 * Kernel Interfaces
238 */
239
240static const struct file_operations sp5100_tco_fops = {
241 .owner = THIS_MODULE,
242 .llseek = no_llseek,
243 .write = sp5100_tco_write,
244 .unlocked_ioctl = sp5100_tco_ioctl,
245 .open = sp5100_tco_open,
246 .release = sp5100_tco_release,
247};
248
249static struct miscdevice sp5100_tco_miscdev = {
250 .minor = WATCHDOG_MINOR,
251 .name = "watchdog",
252 .fops = &sp5100_tco_fops,
253};
254
255/*
256 * Data for PCI driver interface
257 *
258 * This data only exists for exporting the supported
259 * PCI ids via MODULE_DEVICE_TABLE. We do not actually
260 * register a pci_driver, because someone else might
261 * want to register another driver on the same PCI id.
262 */
Wim Van Sebroeck4562f532011-02-21 12:16:44 +0000263static DEFINE_PCI_DEVICE_TABLE(sp5100_tco_pci_tbl) = {
Priyanka Gupta15e28bf2010-10-25 17:58:04 -0700264 { PCI_VENDOR_ID_ATI, PCI_DEVICE_ID_ATI_SBX00_SMBUS, PCI_ANY_ID,
265 PCI_ANY_ID, },
266 { 0, }, /* End of list */
267};
268MODULE_DEVICE_TABLE(pci, sp5100_tco_pci_tbl);
269
270/*
271 * Init & exit routines
272 */
273
274static unsigned char __devinit sp5100_tco_setupdevice(void)
275{
276 struct pci_dev *dev = NULL;
277 u32 val;
278
279 /* Match the PCI device */
280 for_each_pci_dev(dev) {
281 if (pci_match_id(sp5100_tco_pci_tbl, dev) != NULL) {
282 sp5100_tco_pci = dev;
283 break;
284 }
285 }
286
287 if (!sp5100_tco_pci)
288 return 0;
289
290 /* Request the IO ports used by this driver */
291 pm_iobase = SP5100_IO_PM_INDEX_REG;
292 if (!request_region(pm_iobase, SP5100_PM_IOPORTS_SIZE, "SP5100 TCO")) {
Joe Perches27c766a2012-02-15 15:06:19 -0800293 pr_err("I/O address 0x%04x already in use\n", pm_iobase);
Priyanka Gupta15e28bf2010-10-25 17:58:04 -0700294 goto exit;
295 }
296
297 /* Find the watchdog base address. */
298 outb(SP5100_PM_WATCHDOG_BASE3, SP5100_IO_PM_INDEX_REG);
299 val = inb(SP5100_IO_PM_DATA_REG);
300 outb(SP5100_PM_WATCHDOG_BASE2, SP5100_IO_PM_INDEX_REG);
301 val = val << 8 | inb(SP5100_IO_PM_DATA_REG);
302 outb(SP5100_PM_WATCHDOG_BASE1, SP5100_IO_PM_INDEX_REG);
303 val = val << 8 | inb(SP5100_IO_PM_DATA_REG);
304 outb(SP5100_PM_WATCHDOG_BASE0, SP5100_IO_PM_INDEX_REG);
305 /* Low three bits of BASE0 are reserved. */
306 val = val << 8 | (inb(SP5100_IO_PM_DATA_REG) & 0xf8);
307
Yinghai Lu90d241e2011-03-16 20:01:07 -0700308 if (!request_mem_region_exclusive(val, SP5100_WDT_MEM_MAP_SIZE,
309 "SP5100 TCO")) {
Joe Perches27c766a2012-02-15 15:06:19 -0800310 pr_err("mmio address 0x%04x already in use\n", val);
Yinghai Lu90d241e2011-03-16 20:01:07 -0700311 goto unreg_region;
312 }
313 tcobase_phys = val;
314
Priyanka Gupta15e28bf2010-10-25 17:58:04 -0700315 tcobase = ioremap(val, SP5100_WDT_MEM_MAP_SIZE);
H Hartley Sweeten62a9aeb2012-05-02 16:54:43 -0700316 if (!tcobase) {
Joe Perches27c766a2012-02-15 15:06:19 -0800317 pr_err("failed to get tcobase address\n");
Yinghai Lu90d241e2011-03-16 20:01:07 -0700318 goto unreg_mem_region;
Priyanka Gupta15e28bf2010-10-25 17:58:04 -0700319 }
320
321 /* Enable watchdog decode bit */
322 pci_read_config_dword(sp5100_tco_pci,
323 SP5100_PCI_WATCHDOG_MISC_REG,
324 &val);
325
326 val |= SP5100_PCI_WATCHDOG_DECODE_EN;
327
328 pci_write_config_dword(sp5100_tco_pci,
329 SP5100_PCI_WATCHDOG_MISC_REG,
330 val);
331
332 /* Enable Watchdog timer and set the resolution to 1 sec. */
333 outb(SP5100_PM_WATCHDOG_CONTROL, SP5100_IO_PM_INDEX_REG);
334 val = inb(SP5100_IO_PM_DATA_REG);
335 val |= SP5100_PM_WATCHDOG_SECOND_RES;
336 val &= ~SP5100_PM_WATCHDOG_DISABLE;
337 outb(val, SP5100_IO_PM_DATA_REG);
338
339 /* Check that the watchdog action is set to reset the system. */
340 val = readl(SP5100_WDT_CONTROL(tcobase));
341 val &= ~SP5100_PM_WATCHDOG_ACTION_RESET;
342 writel(val, SP5100_WDT_CONTROL(tcobase));
343
344 /* Set a reasonable heartbeat before we stop the timer */
345 tco_timer_set_heartbeat(heartbeat);
346
347 /*
348 * Stop the TCO before we change anything so we don't race with
349 * a zeroed timer.
350 */
351 tco_timer_stop();
352
353 /* Done */
354 return 1;
355
Yinghai Lu90d241e2011-03-16 20:01:07 -0700356unreg_mem_region:
357 release_mem_region(tcobase_phys, SP5100_WDT_MEM_MAP_SIZE);
Priyanka Gupta15e28bf2010-10-25 17:58:04 -0700358unreg_region:
359 release_region(pm_iobase, SP5100_PM_IOPORTS_SIZE);
360exit:
361 return 0;
362}
363
364static int __devinit sp5100_tco_init(struct platform_device *dev)
365{
366 int ret;
367 u32 val;
368
369 /* Check whether or not the hardware watchdog is there. If found, then
370 * set it up.
371 */
372 if (!sp5100_tco_setupdevice())
373 return -ENODEV;
374
375 /* Check to see if last reboot was due to watchdog timeout */
Joe Perches27c766a2012-02-15 15:06:19 -0800376 pr_info("Watchdog reboot %sdetected\n",
377 readl(SP5100_WDT_CONTROL(tcobase)) & SP5100_PM_WATCHDOG_FIRED ?
378 "" : "not ");
Priyanka Gupta15e28bf2010-10-25 17:58:04 -0700379
380 /* Clear out the old status */
381 val = readl(SP5100_WDT_CONTROL(tcobase));
382 val &= ~SP5100_PM_WATCHDOG_FIRED;
383 writel(val, SP5100_WDT_CONTROL(tcobase));
384
385 /*
386 * Check that the heartbeat value is within it's range.
387 * If not, reset to the default.
388 */
389 if (tco_timer_set_heartbeat(heartbeat)) {
390 heartbeat = WATCHDOG_HEARTBEAT;
391 tco_timer_set_heartbeat(heartbeat);
392 }
393
394 ret = misc_register(&sp5100_tco_miscdev);
395 if (ret != 0) {
Joe Perches27c766a2012-02-15 15:06:19 -0800396 pr_err("cannot register miscdev on minor=%d (err=%d)\n",
Priyanka Gupta15e28bf2010-10-25 17:58:04 -0700397 WATCHDOG_MINOR, ret);
398 goto exit;
399 }
400
401 clear_bit(0, &timer_alive);
402
Joe Perches27c766a2012-02-15 15:06:19 -0800403 pr_info("initialized (0x%p). heartbeat=%d sec (nowayout=%d)\n",
Priyanka Gupta15e28bf2010-10-25 17:58:04 -0700404 tcobase, heartbeat, nowayout);
405
406 return 0;
407
408exit:
409 iounmap(tcobase);
Yinghai Lu90d241e2011-03-16 20:01:07 -0700410 release_mem_region(tcobase_phys, SP5100_WDT_MEM_MAP_SIZE);
Priyanka Gupta15e28bf2010-10-25 17:58:04 -0700411 release_region(pm_iobase, SP5100_PM_IOPORTS_SIZE);
412 return ret;
413}
414
415static void __devexit sp5100_tco_cleanup(void)
416{
417 /* Stop the timer before we leave */
418 if (!nowayout)
419 tco_timer_stop();
420
421 /* Deregister */
422 misc_deregister(&sp5100_tco_miscdev);
423 iounmap(tcobase);
Yinghai Lu90d241e2011-03-16 20:01:07 -0700424 release_mem_region(tcobase_phys, SP5100_WDT_MEM_MAP_SIZE);
Priyanka Gupta15e28bf2010-10-25 17:58:04 -0700425 release_region(pm_iobase, SP5100_PM_IOPORTS_SIZE);
426}
427
428static int __devexit sp5100_tco_remove(struct platform_device *dev)
429{
430 if (tcobase)
431 sp5100_tco_cleanup();
432 return 0;
433}
434
435static void sp5100_tco_shutdown(struct platform_device *dev)
436{
437 tco_timer_stop();
438}
439
440static struct platform_driver sp5100_tco_driver = {
441 .probe = sp5100_tco_init,
442 .remove = __devexit_p(sp5100_tco_remove),
443 .shutdown = sp5100_tco_shutdown,
444 .driver = {
445 .owner = THIS_MODULE,
446 .name = TCO_MODULE_NAME,
447 },
448};
449
450static int __init sp5100_tco_init_module(void)
451{
452 int err;
453
Joe Perches27c766a2012-02-15 15:06:19 -0800454 pr_info("SP5100 TCO WatchDog Timer Driver v%s\n", TCO_VERSION);
Priyanka Gupta15e28bf2010-10-25 17:58:04 -0700455
456 err = platform_driver_register(&sp5100_tco_driver);
457 if (err)
458 return err;
459
460 sp5100_tco_platform_device = platform_device_register_simple(
461 TCO_MODULE_NAME, -1, NULL, 0);
462 if (IS_ERR(sp5100_tco_platform_device)) {
463 err = PTR_ERR(sp5100_tco_platform_device);
464 goto unreg_platform_driver;
465 }
466
467 return 0;
468
469unreg_platform_driver:
470 platform_driver_unregister(&sp5100_tco_driver);
471 return err;
472}
473
474static void __exit sp5100_tco_cleanup_module(void)
475{
476 platform_device_unregister(sp5100_tco_platform_device);
477 platform_driver_unregister(&sp5100_tco_driver);
Joe Perches27c766a2012-02-15 15:06:19 -0800478 pr_info("SP5100 TCO Watchdog Module Unloaded\n");
Priyanka Gupta15e28bf2010-10-25 17:58:04 -0700479}
480
481module_init(sp5100_tco_init_module);
482module_exit(sp5100_tco_cleanup_module);
483
484MODULE_AUTHOR("Priyanka Gupta");
485MODULE_DESCRIPTION("TCO timer driver for SP5100 chipset");
486MODULE_LICENSE("GPL");
487MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);