diff options
Diffstat (limited to 'drivers/watchdog/alim1535_wdt.c')
| -rw-r--r-- | drivers/watchdog/alim1535_wdt.c | 465 |
1 files changed, 465 insertions, 0 deletions
diff --git a/drivers/watchdog/alim1535_wdt.c b/drivers/watchdog/alim1535_wdt.c new file mode 100644 index 00000000000..c404fc69e7e --- /dev/null +++ b/drivers/watchdog/alim1535_wdt.c | |||
| @@ -0,0 +1,465 @@ | |||
| 1 | /* | ||
| 2 | * Watchdog for the 7101 PMU version found in the ALi M1535 chipsets | ||
| 3 | * | ||
| 4 | * This program is free software; you can redistribute it and/or | ||
| 5 | * modify it under the terms of the GNU General Public License | ||
| 6 | * as published by the Free Software Foundation; either version | ||
| 7 | * 2 of the License, or (at your option) any later version. | ||
| 8 | */ | ||
| 9 | |||
| 10 | #include <linux/module.h> | ||
| 11 | #include <linux/moduleparam.h> | ||
| 12 | #include <linux/types.h> | ||
| 13 | #include <linux/miscdevice.h> | ||
| 14 | #include <linux/watchdog.h> | ||
| 15 | #include <linux/ioport.h> | ||
| 16 | #include <linux/notifier.h> | ||
| 17 | #include <linux/reboot.h> | ||
| 18 | #include <linux/init.h> | ||
| 19 | #include <linux/fs.h> | ||
| 20 | #include <linux/pci.h> | ||
| 21 | |||
| 22 | #include <asm/uaccess.h> | ||
| 23 | #include <asm/io.h> | ||
| 24 | |||
| 25 | #define WATCHDOG_NAME "ALi_M1535" | ||
| 26 | #define PFX WATCHDOG_NAME ": " | ||
| 27 | #define WATCHDOG_TIMEOUT 60 /* 60 sec default timeout */ | ||
| 28 | |||
| 29 | /* internal variables */ | ||
| 30 | static unsigned long ali_is_open; | ||
| 31 | static char ali_expect_release; | ||
| 32 | static struct pci_dev *ali_pci; | ||
| 33 | static u32 ali_timeout_bits; /* stores the computed timeout */ | ||
| 34 | static spinlock_t ali_lock; /* Guards the hardware */ | ||
| 35 | |||
| 36 | /* module parameters */ | ||
| 37 | static int timeout = WATCHDOG_TIMEOUT; | ||
| 38 | module_param(timeout, int, 0); | ||
| 39 | MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds. (0<timeout<18000, default=" __MODULE_STRING(WATCHDOG_TIMEOUT) ")"); | ||
| 40 | |||
| 41 | static int nowayout = WATCHDOG_NOWAYOUT; | ||
| 42 | module_param(nowayout, int, 0); | ||
| 43 | MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); | ||
| 44 | |||
| 45 | /* | ||
| 46 | * ali_start - start watchdog countdown | ||
| 47 | * | ||
| 48 | * Starts the timer running providing the timer has a counter | ||
| 49 | * configuration set. | ||
| 50 | */ | ||
| 51 | |||
| 52 | static void ali_start(void) | ||
| 53 | { | ||
| 54 | u32 val; | ||
| 55 | |||
| 56 | spin_lock(&ali_lock); | ||
| 57 | |||
| 58 | pci_read_config_dword(ali_pci, 0xCC, &val); | ||
| 59 | val &= ~0x3F; /* Mask count */ | ||
| 60 | val |= (1<<25) | ali_timeout_bits; | ||
| 61 | pci_write_config_dword(ali_pci, 0xCC, val); | ||
| 62 | |||
| 63 | spin_unlock(&ali_lock); | ||
| 64 | } | ||
| 65 | |||
| 66 | /* | ||
| 67 | * ali_stop - stop the timer countdown | ||
| 68 | * | ||
| 69 | * Stop the ALi watchdog countdown | ||
| 70 | */ | ||
| 71 | |||
| 72 | static void ali_stop(void) | ||
| 73 | { | ||
| 74 | u32 val; | ||
| 75 | |||
| 76 | spin_lock(&ali_lock); | ||
| 77 | |||
| 78 | pci_read_config_dword(ali_pci, 0xCC, &val); | ||
| 79 | val &= ~0x3F; /* Mask count to zero (disabled) */ | ||
| 80 | val &= ~(1<<25);/* and for safety mask the reset enable */ | ||
| 81 | pci_write_config_dword(ali_pci, 0xCC, val); | ||
| 82 | |||
| 83 | spin_unlock(&ali_lock); | ||
| 84 | } | ||
| 85 | |||
| 86 | /* | ||
| 87 | * ali_keepalive - send a keepalive to the watchdog | ||
| 88 | * | ||
| 89 | * Send a keepalive to the timer (actually we restart the timer). | ||
| 90 | */ | ||
| 91 | |||
| 92 | static void ali_keepalive(void) | ||
| 93 | { | ||
| 94 | ali_start(); | ||
| 95 | } | ||
| 96 | |||
| 97 | /* | ||
| 98 | * ali_settimer - compute the timer reload value | ||
| 99 | * @t: time in seconds | ||
| 100 | * | ||
| 101 | * Computes the timeout values needed | ||
| 102 | */ | ||
| 103 | |||
| 104 | static int ali_settimer(int t) | ||
| 105 | { | ||
| 106 | if(t < 0) | ||
| 107 | return -EINVAL; | ||
| 108 | else if(t < 60) | ||
| 109 | ali_timeout_bits = t|(1<<6); | ||
| 110 | else if(t < 3600) | ||
| 111 | ali_timeout_bits = (t/60)|(1<<7); | ||
| 112 | else if(t < 18000) | ||
| 113 | ali_timeout_bits = (t/300)|(1<<6)|(1<<7); | ||
| 114 | else return -EINVAL; | ||
| 115 | |||
| 116 | timeout = t; | ||
| 117 | return 0; | ||
| 118 | } | ||
| 119 | |||
| 120 | /* | ||
| 121 | * /dev/watchdog handling | ||
| 122 | */ | ||
| 123 | |||
| 124 | /* | ||
| 125 | * ali_write - writes to ALi watchdog | ||
| 126 | * @file: file from VFS | ||
| 127 | * @data: user address of data | ||
| 128 | * @len: length of data | ||
| 129 | * @ppos: pointer to the file offset | ||
| 130 | * | ||
| 131 | * Handle a write to the ALi watchdog. Writing to the file pings | ||
| 132 | * the watchdog and resets it. Writing the magic 'V' sequence allows | ||
| 133 | * the next close to turn off the watchdog. | ||
| 134 | */ | ||
| 135 | |||
| 136 | static ssize_t ali_write(struct file *file, const char __user *data, | ||
| 137 | size_t len, loff_t * ppos) | ||
| 138 | { | ||
| 139 | /* See if we got the magic character 'V' and reload the timer */ | ||
| 140 | if (len) { | ||
| 141 | if (!nowayout) { | ||
| 142 | size_t i; | ||
| 143 | |||
| 144 | /* note: just in case someone wrote the magic character | ||
| 145 | * five months ago... */ | ||
| 146 | ali_expect_release = 0; | ||
| 147 | |||
| 148 | /* scan to see whether or not we got the magic character */ | ||
| 149 | for (i = 0; i != len; i++) { | ||
| 150 | char c; | ||
| 151 | if(get_user(c, data+i)) | ||
| 152 | return -EFAULT; | ||
| 153 | if (c == 'V') | ||
| 154 | ali_expect_release = 42; | ||
| 155 | } | ||
| 156 | } | ||
| 157 | |||
| 158 | /* someone wrote to us, we should reload the timer */ | ||
| 159 | ali_start(); | ||
| 160 | } | ||
| 161 | return len; | ||
| 162 | } | ||
| 163 | |||
| 164 | /* | ||
| 165 | * ali_ioctl - handle watchdog ioctls | ||
| 166 | * @inode: VFS inode | ||
| 167 | * @file: VFS file pointer | ||
| 168 | * @cmd: ioctl number | ||
| 169 | * @arg: arguments to the ioctl | ||
| 170 | * | ||
| 171 | * Handle the watchdog ioctls supported by the ALi driver. Really | ||
| 172 | * we want an extension to enable irq ack monitoring and the like | ||
| 173 | */ | ||
| 174 | |||
| 175 | static int ali_ioctl(struct inode *inode, struct file *file, | ||
| 176 | unsigned int cmd, unsigned long arg) | ||
| 177 | { | ||
| 178 | void __user *argp = (void __user *)arg; | ||
| 179 | int __user *p = argp; | ||
| 180 | static struct watchdog_info ident = { | ||
| 181 | .options = WDIOF_KEEPALIVEPING | | ||
| 182 | WDIOF_SETTIMEOUT | | ||
| 183 | WDIOF_MAGICCLOSE, | ||
| 184 | .firmware_version = 0, | ||
| 185 | .identity = "ALi M1535 WatchDog Timer", | ||
| 186 | }; | ||
| 187 | |||
| 188 | switch (cmd) { | ||
| 189 | case WDIOC_GETSUPPORT: | ||
| 190 | return copy_to_user(argp, &ident, | ||
| 191 | sizeof (ident)) ? -EFAULT : 0; | ||
| 192 | |||
| 193 | case WDIOC_GETSTATUS: | ||
| 194 | case WDIOC_GETBOOTSTATUS: | ||
| 195 | return put_user(0, p); | ||
| 196 | |||
| 197 | case WDIOC_KEEPALIVE: | ||
| 198 | ali_keepalive(); | ||
| 199 | return 0; | ||
| 200 | |||
| 201 | case WDIOC_SETOPTIONS: | ||
| 202 | { | ||
| 203 | int new_options, retval = -EINVAL; | ||
| 204 | |||
| 205 | if (get_user (new_options, p)) | ||
| 206 | return -EFAULT; | ||
| 207 | |||
| 208 | if (new_options & WDIOS_DISABLECARD) { | ||
| 209 | ali_stop(); | ||
| 210 | retval = 0; | ||
| 211 | } | ||
| 212 | |||
| 213 | if (new_options & WDIOS_ENABLECARD) { | ||
| 214 | ali_start(); | ||
| 215 | retval = 0; | ||
| 216 | } | ||
| 217 | |||
| 218 | return retval; | ||
| 219 | } | ||
| 220 | |||
| 221 | case WDIOC_SETTIMEOUT: | ||
| 222 | { | ||
| 223 | int new_timeout; | ||
| 224 | |||
| 225 | if (get_user(new_timeout, p)) | ||
| 226 | return -EFAULT; | ||
| 227 | |||
| 228 | if (ali_settimer(new_timeout)) | ||
| 229 | return -EINVAL; | ||
| 230 | |||
| 231 | ali_keepalive(); | ||
| 232 | /* Fall */ | ||
| 233 | } | ||
| 234 | |||
| 235 | case WDIOC_GETTIMEOUT: | ||
| 236 | return put_user(timeout, p); | ||
| 237 | |||
| 238 | default: | ||
| 239 | return -ENOTTY; | ||
| 240 | } | ||
| 241 | } | ||
| 242 | |||
| 243 | /* | ||
| 244 | * ali_open - handle open of ali watchdog | ||
| 245 | * @inode: inode from VFS | ||
| 246 | * @file: file from VFS | ||
| 247 | * | ||
| 248 | * Open the ALi watchdog device. Ensure only one person opens it | ||
| 249 | * at a time. Also start the watchdog running. | ||
| 250 | */ | ||
| 251 | |||
| 252 | static int ali_open(struct inode *inode, struct file *file) | ||
| 253 | { | ||
| 254 | /* /dev/watchdog can only be opened once */ | ||
| 255 | if (test_and_set_bit(0, &ali_is_open)) | ||
| 256 | return -EBUSY; | ||
| 257 | |||
| 258 | /* Activate */ | ||
| 259 | ali_start(); | ||
| 260 | return nonseekable_open(inode, file); | ||
| 261 | } | ||
| 262 | |||
| 263 | /* | ||
| 264 | * ali_release - close an ALi watchdog | ||
| 265 | * @inode: inode from VFS | ||
| 266 | * @file: file from VFS | ||
| 267 | * | ||
| 268 | * Close the ALi watchdog device. Actual shutdown of the timer | ||
| 269 | * only occurs if the magic sequence has been set. | ||
| 270 | */ | ||
| 271 | |||
| 272 | static int ali_release(struct inode *inode, struct file *file) | ||
| 273 | { | ||
| 274 | /* | ||
| 275 | * Shut off the timer. | ||
| 276 | */ | ||
| 277 | if (ali_expect_release == 42) { | ||
| 278 | ali_stop(); | ||
| 279 | } else { | ||
| 280 | printk(KERN_CRIT PFX "Unexpected close, not stopping watchdog!\n"); | ||
| 281 | ali_keepalive(); | ||
| 282 | } | ||
| 283 | clear_bit(0, &ali_is_open); | ||
| 284 | ali_expect_release = 0; | ||
| 285 | return 0; | ||
| 286 | } | ||
| 287 | |||
| 288 | /* | ||
| 289 | * ali_notify_sys - System down notifier | ||
| 290 | * | ||
| 291 | * Notifier for system down | ||
| 292 | */ | ||
| 293 | |||
| 294 | |||
| 295 | static int ali_notify_sys(struct notifier_block *this, unsigned long code, void *unused) | ||
| 296 | { | ||
| 297 | if (code==SYS_DOWN || code==SYS_HALT) { | ||
| 298 | /* Turn the WDT off */ | ||
| 299 | ali_stop(); | ||
| 300 | } | ||
| 301 | |||
| 302 | return NOTIFY_DONE; | ||
| 303 | } | ||
| 304 | |||
| 305 | /* | ||
| 306 | * Data for PCI driver interface | ||
| 307 | * | ||
| 308 | * This data only exists for exporting the supported | ||
| 309 | * PCI ids via MODULE_DEVICE_TABLE. We do not actually | ||
| 310 | * register a pci_driver, because someone else might one day | ||
| 311 | * want to register another driver on the same PCI id. | ||
| 312 | */ | ||
| 313 | |||
| 314 | static struct pci_device_id ali_pci_tbl[] = { | ||
| 315 | { PCI_VENDOR_ID_AL, 0x1533, PCI_ANY_ID, PCI_ANY_ID,}, | ||
| 316 | { PCI_VENDOR_ID_AL, 0x1535, PCI_ANY_ID, PCI_ANY_ID,}, | ||
| 317 | { 0, }, | ||
| 318 | }; | ||
| 319 | MODULE_DEVICE_TABLE(pci, ali_pci_tbl); | ||
| 320 | |||
| 321 | /* | ||
| 322 | * ali_find_watchdog - find a 1535 and 7101 | ||
| 323 | * | ||
| 324 | * Scans the PCI hardware for a 1535 series bridge and matching 7101 | ||
| 325 | * watchdog device. This may be overtight but it is better to be safe | ||
| 326 | */ | ||
| 327 | |||
| 328 | static int __init ali_find_watchdog(void) | ||
| 329 | { | ||
| 330 | struct pci_dev *pdev; | ||
| 331 | u32 wdog; | ||
| 332 | |||
| 333 | /* Check for a 1533/1535 series bridge */ | ||
| 334 | pdev = pci_get_device(PCI_VENDOR_ID_AL, 0x1535, NULL); | ||
| 335 | if (pdev == NULL) | ||
| 336 | pdev = pci_get_device(PCI_VENDOR_ID_AL, 0x1533, NULL); | ||
| 337 | if (pdev == NULL) | ||
| 338 | return -ENODEV; | ||
| 339 | pci_dev_put(pdev); | ||
| 340 | |||
| 341 | /* Check for the a 7101 PMU */ | ||
| 342 | pdev = pci_get_device(PCI_VENDOR_ID_AL, 0x7101, NULL); | ||
| 343 | if(pdev == NULL) | ||
| 344 | return -ENODEV; | ||
| 345 | |||
| 346 | if(pci_enable_device(pdev)) { | ||
| 347 | pci_dev_put(pdev); | ||
| 348 | return -EIO; | ||
| 349 | } | ||
| 350 | |||
| 351 | ali_pci = pdev; | ||
| 352 | |||
| 353 | /* | ||
| 354 | * Initialize the timer bits | ||
| 355 | */ | ||
| 356 | pci_read_config_dword(pdev, 0xCC, &wdog); | ||
| 357 | |||
| 358 | wdog &= ~0x3F; /* Timer bits */ | ||
| 359 | wdog &= ~((1<<27)|(1<<26)|(1<<25)|(1<<24)); /* Issued events */ | ||
| 360 | wdog &= ~((1<<16)|(1<<13)|(1<<12)|(1<<11)|(1<<10)|(1<<9)); /* No monitor bits */ | ||
| 361 | |||
| 362 | pci_write_config_dword(pdev, 0xCC, wdog); | ||
| 363 | |||
| 364 | return 0; | ||
| 365 | } | ||
| 366 | |||
| 367 | /* | ||
| 368 | * Kernel Interfaces | ||
| 369 | */ | ||
| 370 | |||
| 371 | static const struct file_operations ali_fops = { | ||
| 372 | .owner = THIS_MODULE, | ||
| 373 | .llseek = no_llseek, | ||
| 374 | .write = ali_write, | ||
| 375 | .ioctl = ali_ioctl, | ||
| 376 | .open = ali_open, | ||
| 377 | .release = ali_release, | ||
| 378 | }; | ||
| 379 | |||
| 380 | static struct miscdevice ali_miscdev = { | ||
| 381 | .minor = WATCHDOG_MINOR, | ||
| 382 | .name = "watchdog", | ||
| 383 | .fops = &ali_fops, | ||
| 384 | }; | ||
| 385 | |||
| 386 | static struct notifier_block ali_notifier = { | ||
| 387 | .notifier_call = ali_notify_sys, | ||
| 388 | }; | ||
| 389 | |||
| 390 | /* | ||
| 391 | * watchdog_init - module initialiser | ||
| 392 | * | ||
| 393 | * Scan for a suitable watchdog and if so initialize it. Return an error | ||
| 394 | * if we cannot, the error causes the module to unload | ||
| 395 | */ | ||
| 396 | |||
| 397 | static int __init watchdog_init(void) | ||
| 398 | { | ||
| 399 | int ret; | ||
| 400 | |||
| 401 | spin_lock_init(&ali_lock); | ||
| 402 | |||
| 403 | /* Check whether or not the hardware watchdog is there */ | ||
| 404 | if (ali_find_watchdog() != 0) { | ||
| 405 | return -ENODEV; | ||
| 406 | } | ||
| 407 | |||
| 408 | /* Check that the timeout value is within it's range ; if not reset to the default */ | ||
| 409 | if (timeout < 1 || timeout >= 18000) { | ||
| 410 | timeout = WATCHDOG_TIMEOUT; | ||
| 411 | printk(KERN_INFO PFX "timeout value must be 0<timeout<18000, using %d\n", | ||
| 412 | timeout); | ||
| 413 | } | ||
| 414 | |||
| 415 | /* Calculate the watchdog's timeout */ | ||
| 416 | ali_settimer(timeout); | ||
| 417 | |||
| 418 | ret = misc_register(&ali_miscdev); | ||
| 419 | if (ret != 0) { | ||
| 420 | printk(KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n", | ||
| 421 | WATCHDOG_MINOR, ret); | ||
| 422 | goto out; | ||
| 423 | } | ||
| 424 | |||
| 425 | ret = register_reboot_notifier(&ali_notifier); | ||
| 426 | if (ret != 0) { | ||
| 427 | printk(KERN_ERR PFX "cannot register reboot notifier (err=%d)\n", | ||
| 428 | ret); | ||
| 429 | goto unreg_miscdev; | ||
| 430 | } | ||
| 431 | |||
| 432 | printk(KERN_INFO PFX "initialized. timeout=%d sec (nowayout=%d)\n", | ||
| 433 | timeout, nowayout); | ||
| 434 | |||
| 435 | out: | ||
| 436 | return ret; | ||
| 437 | unreg_miscdev: | ||
| 438 | misc_deregister(&ali_miscdev); | ||
| 439 | goto out; | ||
| 440 | } | ||
| 441 | |||
| 442 | /* | ||
| 443 | * watchdog_exit - module de-initialiser | ||
| 444 | * | ||
| 445 | * Called while unloading a successfully installed watchdog module. | ||
| 446 | */ | ||
| 447 | |||
| 448 | static void __exit watchdog_exit(void) | ||
| 449 | { | ||
| 450 | /* Stop the timer before we leave */ | ||
| 451 | ali_stop(); | ||
| 452 | |||
| 453 | /* Deregister */ | ||
| 454 | unregister_reboot_notifier(&ali_notifier); | ||
| 455 | misc_deregister(&ali_miscdev); | ||
| 456 | pci_dev_put(ali_pci); | ||
| 457 | } | ||
| 458 | |||
| 459 | module_init(watchdog_init); | ||
| 460 | module_exit(watchdog_exit); | ||
| 461 | |||
| 462 | MODULE_AUTHOR("Alan Cox"); | ||
| 463 | MODULE_DESCRIPTION("ALi M1535 PMU Watchdog Timer driver"); | ||
| 464 | MODULE_LICENSE("GPL"); | ||
| 465 | MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); | ||
