Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* cpwatchdog.c - driver implementation for hardware watchdog |
| 2 | * timers found on Sun Microsystems CP1400 and CP1500 boards. |
| 3 | * |
| 4 | * This device supports both the generic Linux watchdog |
| 5 | * interface and Solaris-compatible ioctls as best it is |
| 6 | * able. |
| 7 | * |
| 8 | * NOTE: CP1400 systems appear to have a defective intr_mask |
| 9 | * register on the PLD, preventing the disabling of |
| 10 | * timer interrupts. We use a timer to periodically |
| 11 | * reset 'stopped' watchdogs on affected platforms. |
| 12 | * |
| 13 | * TODO: DevFS support (/dev/watchdogs/0 ... /dev/watchdogs/2) |
| 14 | * |
| 15 | * Copyright (c) 2000 Eric Brower (ebrower@usa.net) |
| 16 | */ |
| 17 | |
| 18 | #include <linux/kernel.h> |
| 19 | #include <linux/module.h> |
| 20 | #include <linux/fs.h> |
| 21 | #include <linux/errno.h> |
| 22 | #include <linux/major.h> |
| 23 | #include <linux/init.h> |
| 24 | #include <linux/miscdevice.h> |
| 25 | #include <linux/sched.h> |
| 26 | #include <linux/interrupt.h> |
| 27 | #include <linux/ioport.h> |
| 28 | #include <linux/timer.h> |
Christoph Hellwig | b66621f | 2005-11-07 14:13:14 -0800 | [diff] [blame] | 29 | #include <linux/smp_lock.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 30 | #include <asm/irq.h> |
| 31 | #include <asm/ebus.h> |
| 32 | #include <asm/oplib.h> |
| 33 | #include <asm/uaccess.h> |
| 34 | |
| 35 | #include <asm/watchdog.h> |
| 36 | |
| 37 | #define WD_OBPNAME "watchdog" |
| 38 | #define WD_BADMODEL "SUNW,501-5336" |
| 39 | #define WD_BTIMEOUT (jiffies + (HZ * 1000)) |
| 40 | #define WD_BLIMIT 0xFFFF |
| 41 | |
| 42 | #define WD0_DEVNAME "watchdog0" |
| 43 | #define WD1_DEVNAME "watchdog1" |
| 44 | #define WD2_DEVNAME "watchdog2" |
| 45 | |
| 46 | #define WD0_MINOR 212 |
| 47 | #define WD1_MINOR 213 |
| 48 | #define WD2_MINOR 214 |
| 49 | |
| 50 | |
| 51 | /* Internal driver definitions |
| 52 | */ |
| 53 | #define WD0_ID 0 /* Watchdog0 */ |
| 54 | #define WD1_ID 1 /* Watchdog1 */ |
| 55 | #define WD2_ID 2 /* Watchdog2 */ |
| 56 | #define WD_NUMDEVS 3 /* Device contains 3 timers */ |
| 57 | |
| 58 | #define WD_INTR_OFF 0 /* Interrupt disable value */ |
| 59 | #define WD_INTR_ON 1 /* Interrupt enable value */ |
| 60 | |
| 61 | #define WD_STAT_INIT 0x01 /* Watchdog timer is initialized */ |
| 62 | #define WD_STAT_BSTOP 0x02 /* Watchdog timer is brokenstopped */ |
| 63 | #define WD_STAT_SVCD 0x04 /* Watchdog interrupt occurred */ |
| 64 | |
| 65 | /* Register value definitions |
| 66 | */ |
| 67 | #define WD0_INTR_MASK 0x01 /* Watchdog device interrupt masks */ |
| 68 | #define WD1_INTR_MASK 0x02 |
| 69 | #define WD2_INTR_MASK 0x04 |
| 70 | |
| 71 | #define WD_S_RUNNING 0x01 /* Watchdog device status running */ |
| 72 | #define WD_S_EXPIRED 0x02 /* Watchdog device status expired */ |
| 73 | |
| 74 | /* Sun uses Altera PLD EPF8820ATC144-4 |
| 75 | * providing three hardware watchdogs: |
| 76 | * |
| 77 | * 1) RIC - sends an interrupt when triggered |
| 78 | * 2) XIR - asserts XIR_B_RESET when triggered, resets CPU |
| 79 | * 3) POR - asserts POR_B_RESET when triggered, resets CPU, backplane, board |
| 80 | * |
| 81 | *** Timer register block definition (struct wd_timer_regblk) |
| 82 | * |
| 83 | * dcntr and limit registers (halfword access): |
| 84 | * ------------------- |
| 85 | * | 15 | ...| 1 | 0 | |
| 86 | * ------------------- |
| 87 | * |- counter val -| |
| 88 | * ------------------- |
| 89 | * dcntr - Current 16-bit downcounter value. |
| 90 | * When downcounter reaches '0' watchdog expires. |
| 91 | * Reading this register resets downcounter with 'limit' value. |
| 92 | * limit - 16-bit countdown value in 1/10th second increments. |
| 93 | * Writing this register begins countdown with input value. |
| 94 | * Reading from this register does not affect counter. |
| 95 | * NOTES: After watchdog reset, dcntr and limit contain '1' |
| 96 | * |
| 97 | * status register (byte access): |
| 98 | * --------------------------- |
| 99 | * | 7 | ... | 2 | 1 | 0 | |
| 100 | * --------------+------------ |
| 101 | * |- UNUSED -| EXP | RUN | |
| 102 | * --------------------------- |
| 103 | * status- Bit 0 - Watchdog is running |
| 104 | * Bit 1 - Watchdog has expired |
| 105 | * |
| 106 | *** PLD register block definition (struct wd_pld_regblk) |
| 107 | * |
| 108 | * intr_mask register (byte access): |
| 109 | * --------------------------------- |
| 110 | * | 7 | ... | 3 | 2 | 1 | 0 | |
| 111 | * +-------------+------------------ |
| 112 | * |- UNUSED -| WD3 | WD2 | WD1 | |
| 113 | * --------------------------------- |
| 114 | * WD3 - 1 == Interrupt disabled for watchdog 3 |
| 115 | * WD2 - 1 == Interrupt disabled for watchdog 2 |
| 116 | * WD1 - 1 == Interrupt disabled for watchdog 1 |
| 117 | * |
| 118 | * pld_status register (byte access): |
| 119 | * UNKNOWN, MAGICAL MYSTERY REGISTER |
| 120 | * |
| 121 | */ |
| 122 | #define WD_TIMER_REGSZ 16 |
| 123 | #define WD0_OFF 0 |
| 124 | #define WD1_OFF (WD_TIMER_REGSZ * 1) |
| 125 | #define WD2_OFF (WD_TIMER_REGSZ * 2) |
| 126 | #define PLD_OFF (WD_TIMER_REGSZ * 3) |
| 127 | |
| 128 | #define WD_DCNTR 0x00 |
| 129 | #define WD_LIMIT 0x04 |
| 130 | #define WD_STATUS 0x08 |
| 131 | |
| 132 | #define PLD_IMASK (PLD_OFF + 0x00) |
| 133 | #define PLD_STATUS (PLD_OFF + 0x04) |
| 134 | |
| 135 | /* Individual timer structure |
| 136 | */ |
| 137 | struct wd_timer { |
| 138 | __u16 timeout; |
| 139 | __u8 intr_mask; |
| 140 | unsigned char runstatus; |
| 141 | void __iomem *regs; |
| 142 | }; |
| 143 | |
| 144 | /* Device structure |
| 145 | */ |
| 146 | struct wd_device { |
| 147 | int irq; |
| 148 | spinlock_t lock; |
| 149 | unsigned char isbaddoggie; /* defective PLD */ |
| 150 | unsigned char opt_enable; |
| 151 | unsigned char opt_reboot; |
| 152 | unsigned short opt_timeout; |
| 153 | unsigned char initialized; |
| 154 | struct wd_timer watchdog[WD_NUMDEVS]; |
| 155 | void __iomem *regs; |
| 156 | }; |
| 157 | |
| 158 | static struct wd_device wd_dev = { |
| 159 | 0, SPIN_LOCK_UNLOCKED, 0, 0, 0, 0, |
| 160 | }; |
| 161 | |
| 162 | static struct timer_list wd_timer; |
| 163 | |
| 164 | static int wd0_timeout = 0; |
| 165 | static int wd1_timeout = 0; |
| 166 | static int wd2_timeout = 0; |
| 167 | |
| 168 | #ifdef MODULE |
| 169 | module_param (wd0_timeout, int, 0); |
| 170 | MODULE_PARM_DESC(wd0_timeout, "Default watchdog0 timeout in 1/10secs"); |
| 171 | module_param (wd1_timeout, int, 0); |
| 172 | MODULE_PARM_DESC(wd1_timeout, "Default watchdog1 timeout in 1/10secs"); |
| 173 | module_param (wd2_timeout, int, 0); |
| 174 | MODULE_PARM_DESC(wd2_timeout, "Default watchdog2 timeout in 1/10secs"); |
| 175 | |
| 176 | MODULE_AUTHOR |
| 177 | ("Eric Brower <ebrower@usa.net>"); |
| 178 | MODULE_DESCRIPTION |
| 179 | ("Hardware watchdog driver for Sun Microsystems CP1400/1500"); |
| 180 | MODULE_LICENSE("GPL"); |
| 181 | MODULE_SUPPORTED_DEVICE |
| 182 | ("watchdog"); |
| 183 | #endif /* ifdef MODULE */ |
| 184 | |
| 185 | /* Forward declarations of internal methods |
| 186 | */ |
| 187 | #ifdef WD_DEBUG |
| 188 | static void wd_dumpregs(void); |
| 189 | #endif |
| 190 | static irqreturn_t wd_interrupt(int irq, void *dev_id, struct pt_regs *regs); |
| 191 | static void wd_toggleintr(struct wd_timer* pTimer, int enable); |
| 192 | static void wd_pingtimer(struct wd_timer* pTimer); |
| 193 | static void wd_starttimer(struct wd_timer* pTimer); |
| 194 | static void wd_resetbrokentimer(struct wd_timer* pTimer); |
| 195 | static void wd_stoptimer(struct wd_timer* pTimer); |
| 196 | static void wd_brokentimer(unsigned long data); |
| 197 | static int wd_getstatus(struct wd_timer* pTimer); |
| 198 | |
| 199 | /* PLD expects words to be written in LSB format, |
| 200 | * so we must flip all words prior to writing them to regs |
| 201 | */ |
| 202 | static inline unsigned short flip_word(unsigned short word) |
| 203 | { |
| 204 | return ((word & 0xff) << 8) | ((word >> 8) & 0xff); |
| 205 | } |
| 206 | |
| 207 | #define wd_writew(val, addr) (writew(flip_word(val), addr)) |
| 208 | #define wd_readw(addr) (flip_word(readw(addr))) |
| 209 | #define wd_writeb(val, addr) (writeb(val, addr)) |
| 210 | #define wd_readb(addr) (readb(addr)) |
| 211 | |
| 212 | |
| 213 | /* CP1400s seem to have broken PLD implementations-- |
| 214 | * the interrupt_mask register cannot be written, so |
| 215 | * no timer interrupts can be masked within the PLD. |
| 216 | */ |
| 217 | static inline int wd_isbroken(void) |
| 218 | { |
| 219 | /* we could test this by read/write/read/restore |
| 220 | * on the interrupt mask register only if OBP |
| 221 | * 'watchdog-enable?' == FALSE, but it seems |
| 222 | * ubiquitous on CP1400s |
| 223 | */ |
| 224 | char val[32]; |
| 225 | prom_getproperty(prom_root_node, "model", val, sizeof(val)); |
| 226 | return((!strcmp(val, WD_BADMODEL)) ? 1 : 0); |
| 227 | } |
| 228 | |
| 229 | /* Retrieve watchdog-enable? option from OBP |
| 230 | * Returns 0 if false, 1 if true |
| 231 | */ |
| 232 | static inline int wd_opt_enable(void) |
| 233 | { |
| 234 | int opt_node; |
| 235 | |
| 236 | opt_node = prom_getchild(prom_root_node); |
| 237 | opt_node = prom_searchsiblings(opt_node, "options"); |
| 238 | return((-1 == prom_getint(opt_node, "watchdog-enable?")) ? 0 : 1); |
| 239 | } |
| 240 | |
| 241 | /* Retrieve watchdog-reboot? option from OBP |
| 242 | * Returns 0 if false, 1 if true |
| 243 | */ |
| 244 | static inline int wd_opt_reboot(void) |
| 245 | { |
| 246 | int opt_node; |
| 247 | |
| 248 | opt_node = prom_getchild(prom_root_node); |
| 249 | opt_node = prom_searchsiblings(opt_node, "options"); |
| 250 | return((-1 == prom_getint(opt_node, "watchdog-reboot?")) ? 0 : 1); |
| 251 | } |
| 252 | |
| 253 | /* Retrieve watchdog-timeout option from OBP |
| 254 | * Returns OBP value, or 0 if not located |
| 255 | */ |
| 256 | static inline int wd_opt_timeout(void) |
| 257 | { |
| 258 | int opt_node; |
| 259 | char value[32]; |
| 260 | char *p = value; |
| 261 | |
| 262 | opt_node = prom_getchild(prom_root_node); |
| 263 | opt_node = prom_searchsiblings(opt_node, "options"); |
| 264 | opt_node = prom_getproperty(opt_node, |
| 265 | "watchdog-timeout", |
| 266 | value, |
| 267 | sizeof(value)); |
| 268 | if(-1 != opt_node) { |
| 269 | /* atoi implementation */ |
| 270 | for(opt_node = 0; /* nop */; p++) { |
| 271 | if(*p >= '0' && *p <= '9') { |
| 272 | opt_node = (10*opt_node)+(*p-'0'); |
| 273 | } |
| 274 | else { |
| 275 | break; |
| 276 | } |
| 277 | } |
| 278 | } |
| 279 | return((-1 == opt_node) ? (0) : (opt_node)); |
| 280 | } |
| 281 | |
| 282 | static int wd_open(struct inode *inode, struct file *f) |
| 283 | { |
| 284 | switch(iminor(inode)) |
| 285 | { |
| 286 | case WD0_MINOR: |
| 287 | f->private_data = &wd_dev.watchdog[WD0_ID]; |
| 288 | break; |
| 289 | case WD1_MINOR: |
| 290 | f->private_data = &wd_dev.watchdog[WD1_ID]; |
| 291 | break; |
| 292 | case WD2_MINOR: |
| 293 | f->private_data = &wd_dev.watchdog[WD2_ID]; |
| 294 | break; |
| 295 | default: |
| 296 | return(-ENODEV); |
| 297 | } |
| 298 | |
| 299 | /* Register IRQ on first open of device */ |
| 300 | if(0 == wd_dev.initialized) |
| 301 | { |
| 302 | if (request_irq(wd_dev.irq, |
| 303 | &wd_interrupt, |
| 304 | SA_SHIRQ, |
| 305 | WD_OBPNAME, |
| 306 | (void *)wd_dev.regs)) { |
David S. Miller | c6387a4 | 2006-06-20 01:21:29 -0700 | [diff] [blame] | 307 | printk("%s: Cannot register IRQ %d\n", |
| 308 | WD_OBPNAME, wd_dev.irq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 309 | return(-EBUSY); |
| 310 | } |
| 311 | wd_dev.initialized = 1; |
| 312 | } |
| 313 | |
| 314 | return(nonseekable_open(inode, f)); |
| 315 | } |
| 316 | |
| 317 | static int wd_release(struct inode *inode, struct file *file) |
| 318 | { |
| 319 | return 0; |
| 320 | } |
| 321 | |
| 322 | static int wd_ioctl(struct inode *inode, struct file *file, |
| 323 | unsigned int cmd, unsigned long arg) |
| 324 | { |
| 325 | int setopt = 0; |
| 326 | struct wd_timer* pTimer = (struct wd_timer*)file->private_data; |
| 327 | void __user *argp = (void __user *)arg; |
| 328 | struct watchdog_info info = { |
| 329 | 0, |
| 330 | 0, |
| 331 | "Altera EPF8820ATC144-4" |
| 332 | }; |
| 333 | |
| 334 | if(NULL == pTimer) { |
| 335 | return(-EINVAL); |
| 336 | } |
| 337 | |
| 338 | switch(cmd) |
| 339 | { |
| 340 | /* Generic Linux IOCTLs */ |
| 341 | case WDIOC_GETSUPPORT: |
| 342 | if(copy_to_user(argp, &info, sizeof(struct watchdog_info))) { |
| 343 | return(-EFAULT); |
| 344 | } |
| 345 | break; |
| 346 | case WDIOC_GETSTATUS: |
| 347 | case WDIOC_GETBOOTSTATUS: |
| 348 | if (put_user(0, (int __user *)argp)) |
| 349 | return -EFAULT; |
| 350 | break; |
| 351 | case WDIOC_KEEPALIVE: |
| 352 | wd_pingtimer(pTimer); |
| 353 | break; |
| 354 | case WDIOC_SETOPTIONS: |
| 355 | if(copy_from_user(&setopt, argp, sizeof(unsigned int))) { |
| 356 | return -EFAULT; |
| 357 | } |
| 358 | if(setopt & WDIOS_DISABLECARD) { |
| 359 | if(wd_dev.opt_enable) { |
| 360 | printk( |
| 361 | "%s: cannot disable watchdog in ENABLED mode\n", |
| 362 | WD_OBPNAME); |
| 363 | return(-EINVAL); |
| 364 | } |
| 365 | wd_stoptimer(pTimer); |
| 366 | } |
| 367 | else if(setopt & WDIOS_ENABLECARD) { |
| 368 | wd_starttimer(pTimer); |
| 369 | } |
| 370 | else { |
| 371 | return(-EINVAL); |
| 372 | } |
| 373 | break; |
| 374 | /* Solaris-compatible IOCTLs */ |
| 375 | case WIOCGSTAT: |
| 376 | setopt = wd_getstatus(pTimer); |
| 377 | if(copy_to_user(argp, &setopt, sizeof(unsigned int))) { |
| 378 | return(-EFAULT); |
| 379 | } |
| 380 | break; |
| 381 | case WIOCSTART: |
| 382 | wd_starttimer(pTimer); |
| 383 | break; |
| 384 | case WIOCSTOP: |
| 385 | if(wd_dev.opt_enable) { |
| 386 | printk("%s: cannot disable watchdog in ENABLED mode\n", |
| 387 | WD_OBPNAME); |
| 388 | return(-EINVAL); |
| 389 | } |
| 390 | wd_stoptimer(pTimer); |
| 391 | break; |
| 392 | default: |
| 393 | return(-EINVAL); |
| 394 | } |
| 395 | return(0); |
| 396 | } |
| 397 | |
Christoph Hellwig | b66621f | 2005-11-07 14:13:14 -0800 | [diff] [blame] | 398 | static long wd_compat_ioctl(struct file *file, unsigned int cmd, |
| 399 | unsigned long arg) |
| 400 | { |
| 401 | int rval = -ENOIOCTLCMD; |
| 402 | |
| 403 | switch (cmd) { |
| 404 | /* solaris ioctls are specific to this driver */ |
| 405 | case WIOCSTART: |
| 406 | case WIOCSTOP: |
| 407 | case WIOCGSTAT: |
| 408 | lock_kernel(); |
| 409 | rval = wd_ioctl(file->f_dentry->d_inode, file, cmd, arg); |
David S. Miller | feee207 | 2005-11-09 12:05:37 -0800 | [diff] [blame] | 410 | unlock_kernel(); |
Christoph Hellwig | b66621f | 2005-11-07 14:13:14 -0800 | [diff] [blame] | 411 | break; |
| 412 | /* everything else is handled by the generic compat layer */ |
| 413 | default: |
| 414 | break; |
| 415 | } |
| 416 | |
| 417 | return rval; |
| 418 | } |
| 419 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 420 | static ssize_t wd_write(struct file *file, |
| 421 | const char __user *buf, |
| 422 | size_t count, |
| 423 | loff_t *ppos) |
| 424 | { |
| 425 | struct wd_timer* pTimer = (struct wd_timer*)file->private_data; |
| 426 | |
| 427 | if(NULL == pTimer) { |
| 428 | return(-EINVAL); |
| 429 | } |
| 430 | |
| 431 | if (count) { |
| 432 | wd_pingtimer(pTimer); |
| 433 | return 1; |
| 434 | } |
| 435 | return 0; |
| 436 | } |
| 437 | |
| 438 | static ssize_t wd_read(struct file * file, char __user *buffer, |
| 439 | size_t count, loff_t *ppos) |
| 440 | { |
| 441 | #ifdef WD_DEBUG |
| 442 | wd_dumpregs(); |
| 443 | return(0); |
| 444 | #else |
| 445 | return(-EINVAL); |
| 446 | #endif /* ifdef WD_DEBUG */ |
| 447 | } |
| 448 | |
| 449 | static irqreturn_t wd_interrupt(int irq, void *dev_id, struct pt_regs *regs) |
| 450 | { |
| 451 | /* Only WD0 will interrupt-- others are NMI and we won't |
| 452 | * see them here.... |
| 453 | */ |
| 454 | spin_lock_irq(&wd_dev.lock); |
| 455 | if((unsigned long)wd_dev.regs == (unsigned long)dev_id) |
| 456 | { |
| 457 | wd_stoptimer(&wd_dev.watchdog[WD0_ID]); |
| 458 | wd_dev.watchdog[WD0_ID].runstatus |= WD_STAT_SVCD; |
| 459 | } |
| 460 | spin_unlock_irq(&wd_dev.lock); |
| 461 | return IRQ_HANDLED; |
| 462 | } |
| 463 | |
| 464 | static struct file_operations wd_fops = { |
| 465 | .owner = THIS_MODULE, |
| 466 | .ioctl = wd_ioctl, |
Christoph Hellwig | b66621f | 2005-11-07 14:13:14 -0800 | [diff] [blame] | 467 | .compat_ioctl = wd_compat_ioctl, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 468 | .open = wd_open, |
| 469 | .write = wd_write, |
| 470 | .read = wd_read, |
| 471 | .release = wd_release, |
| 472 | }; |
| 473 | |
| 474 | static struct miscdevice wd0_miscdev = { WD0_MINOR, WD0_DEVNAME, &wd_fops }; |
| 475 | static struct miscdevice wd1_miscdev = { WD1_MINOR, WD1_DEVNAME, &wd_fops }; |
| 476 | static struct miscdevice wd2_miscdev = { WD2_MINOR, WD2_DEVNAME, &wd_fops }; |
| 477 | |
| 478 | #ifdef WD_DEBUG |
| 479 | static void wd_dumpregs(void) |
| 480 | { |
| 481 | /* Reading from downcounters initiates watchdog countdown-- |
| 482 | * Example is included below for illustration purposes. |
| 483 | */ |
| 484 | int i; |
| 485 | printk("%s: dumping register values\n", WD_OBPNAME); |
| 486 | for(i = WD0_ID; i < WD_NUMDEVS; ++i) { |
| 487 | /* printk("\t%s%i: dcntr at 0x%lx: 0x%x\n", |
| 488 | * WD_OBPNAME, |
| 489 | * i, |
| 490 | * (unsigned long)(&wd_dev.watchdog[i].regs->dcntr), |
| 491 | * readw(&wd_dev.watchdog[i].regs->dcntr)); |
| 492 | */ |
| 493 | printk("\t%s%i: limit at 0x%lx: 0x%x\n", |
| 494 | WD_OBPNAME, |
| 495 | i, |
| 496 | (unsigned long)(&wd_dev.watchdog[i].regs->limit), |
| 497 | readw(&wd_dev.watchdog[i].regs->limit)); |
| 498 | printk("\t%s%i: status at 0x%lx: 0x%x\n", |
| 499 | WD_OBPNAME, |
| 500 | i, |
| 501 | (unsigned long)(&wd_dev.watchdog[i].regs->status), |
| 502 | readb(&wd_dev.watchdog[i].regs->status)); |
| 503 | printk("\t%s%i: driver status: 0x%x\n", |
| 504 | WD_OBPNAME, |
| 505 | i, |
| 506 | wd_getstatus(&wd_dev.watchdog[i])); |
| 507 | } |
| 508 | printk("\tintr_mask at %p: 0x%x\n", |
| 509 | wd_dev.regs + PLD_IMASK, |
| 510 | readb(wd_dev.regs + PLD_IMASK)); |
| 511 | printk("\tpld_status at %p: 0x%x\n", |
| 512 | wd_dev.regs + PLD_STATUS, |
| 513 | readb(wd_dev.regs + PLD_STATUS)); |
| 514 | } |
| 515 | #endif |
| 516 | |
| 517 | /* Enable or disable watchdog interrupts |
| 518 | * Because of the CP1400 defect this should only be |
| 519 | * called during initialzation or by wd_[start|stop]timer() |
| 520 | * |
| 521 | * pTimer - pointer to timer device, or NULL to indicate all timers |
| 522 | * enable - non-zero to enable interrupts, zero to disable |
| 523 | */ |
| 524 | static void wd_toggleintr(struct wd_timer* pTimer, int enable) |
| 525 | { |
| 526 | unsigned char curregs = wd_readb(wd_dev.regs + PLD_IMASK); |
| 527 | unsigned char setregs = |
| 528 | (NULL == pTimer) ? |
| 529 | (WD0_INTR_MASK | WD1_INTR_MASK | WD2_INTR_MASK) : |
| 530 | (pTimer->intr_mask); |
| 531 | |
| 532 | (WD_INTR_ON == enable) ? |
| 533 | (curregs &= ~setregs): |
| 534 | (curregs |= setregs); |
| 535 | |
| 536 | wd_writeb(curregs, wd_dev.regs + PLD_IMASK); |
| 537 | return; |
| 538 | } |
| 539 | |
| 540 | /* Reset countdown timer with 'limit' value and continue countdown. |
| 541 | * This will not start a stopped timer. |
| 542 | * |
| 543 | * pTimer - pointer to timer device |
| 544 | */ |
| 545 | static void wd_pingtimer(struct wd_timer* pTimer) |
| 546 | { |
| 547 | if (wd_readb(pTimer->regs + WD_STATUS) & WD_S_RUNNING) { |
| 548 | wd_readw(pTimer->regs + WD_DCNTR); |
| 549 | } |
| 550 | } |
| 551 | |
| 552 | /* Stop a running watchdog timer-- the timer actually keeps |
| 553 | * running, but the interrupt is masked so that no action is |
| 554 | * taken upon expiration. |
| 555 | * |
| 556 | * pTimer - pointer to timer device |
| 557 | */ |
| 558 | static void wd_stoptimer(struct wd_timer* pTimer) |
| 559 | { |
| 560 | if(wd_readb(pTimer->regs + WD_STATUS) & WD_S_RUNNING) { |
| 561 | wd_toggleintr(pTimer, WD_INTR_OFF); |
| 562 | |
| 563 | if(wd_dev.isbaddoggie) { |
| 564 | pTimer->runstatus |= WD_STAT_BSTOP; |
| 565 | wd_brokentimer((unsigned long)&wd_dev); |
| 566 | } |
| 567 | } |
| 568 | } |
| 569 | |
| 570 | /* Start a watchdog timer with the specified limit value |
| 571 | * If the watchdog is running, it will be restarted with |
| 572 | * the provided limit value. |
| 573 | * |
| 574 | * This function will enable interrupts on the specified |
| 575 | * watchdog. |
| 576 | * |
| 577 | * pTimer - pointer to timer device |
| 578 | * limit - limit (countdown) value in 1/10th seconds |
| 579 | */ |
| 580 | static void wd_starttimer(struct wd_timer* pTimer) |
| 581 | { |
| 582 | if(wd_dev.isbaddoggie) { |
| 583 | pTimer->runstatus &= ~WD_STAT_BSTOP; |
| 584 | } |
| 585 | pTimer->runstatus &= ~WD_STAT_SVCD; |
| 586 | |
| 587 | wd_writew(pTimer->timeout, pTimer->regs + WD_LIMIT); |
| 588 | wd_toggleintr(pTimer, WD_INTR_ON); |
| 589 | } |
| 590 | |
| 591 | /* Restarts timer with maximum limit value and |
| 592 | * does not unset 'brokenstop' value. |
| 593 | */ |
| 594 | static void wd_resetbrokentimer(struct wd_timer* pTimer) |
| 595 | { |
| 596 | wd_toggleintr(pTimer, WD_INTR_ON); |
| 597 | wd_writew(WD_BLIMIT, pTimer->regs + WD_LIMIT); |
| 598 | } |
| 599 | |
| 600 | /* Timer device initialization helper. |
| 601 | * Returns 0 on success, other on failure |
| 602 | */ |
| 603 | static int wd_inittimer(int whichdog) |
| 604 | { |
| 605 | struct miscdevice *whichmisc; |
| 606 | void __iomem *whichregs; |
| 607 | char whichident[8]; |
| 608 | int whichmask; |
| 609 | __u16 whichlimit; |
| 610 | |
| 611 | switch(whichdog) |
| 612 | { |
| 613 | case WD0_ID: |
| 614 | whichmisc = &wd0_miscdev; |
| 615 | strcpy(whichident, "RIC"); |
| 616 | whichregs = wd_dev.regs + WD0_OFF; |
| 617 | whichmask = WD0_INTR_MASK; |
| 618 | whichlimit= (0 == wd0_timeout) ? |
| 619 | (wd_dev.opt_timeout): |
| 620 | (wd0_timeout); |
| 621 | break; |
| 622 | case WD1_ID: |
| 623 | whichmisc = &wd1_miscdev; |
| 624 | strcpy(whichident, "XIR"); |
| 625 | whichregs = wd_dev.regs + WD1_OFF; |
| 626 | whichmask = WD1_INTR_MASK; |
| 627 | whichlimit= (0 == wd1_timeout) ? |
| 628 | (wd_dev.opt_timeout): |
| 629 | (wd1_timeout); |
| 630 | break; |
| 631 | case WD2_ID: |
| 632 | whichmisc = &wd2_miscdev; |
| 633 | strcpy(whichident, "POR"); |
| 634 | whichregs = wd_dev.regs + WD2_OFF; |
| 635 | whichmask = WD2_INTR_MASK; |
| 636 | whichlimit= (0 == wd2_timeout) ? |
| 637 | (wd_dev.opt_timeout): |
| 638 | (wd2_timeout); |
| 639 | break; |
| 640 | default: |
| 641 | printk("%s: %s: invalid watchdog id: %i\n", |
| 642 | WD_OBPNAME, __FUNCTION__, whichdog); |
| 643 | return(1); |
| 644 | } |
| 645 | if(0 != misc_register(whichmisc)) |
| 646 | { |
| 647 | return(1); |
| 648 | } |
| 649 | wd_dev.watchdog[whichdog].regs = whichregs; |
| 650 | wd_dev.watchdog[whichdog].timeout = whichlimit; |
| 651 | wd_dev.watchdog[whichdog].intr_mask = whichmask; |
| 652 | wd_dev.watchdog[whichdog].runstatus &= ~WD_STAT_BSTOP; |
| 653 | wd_dev.watchdog[whichdog].runstatus |= WD_STAT_INIT; |
| 654 | |
| 655 | printk("%s%i: %s hardware watchdog [%01i.%i sec] %s\n", |
| 656 | WD_OBPNAME, |
| 657 | whichdog, |
| 658 | whichident, |
| 659 | wd_dev.watchdog[whichdog].timeout / 10, |
| 660 | wd_dev.watchdog[whichdog].timeout % 10, |
| 661 | (0 != wd_dev.opt_enable) ? "in ENABLED mode" : ""); |
| 662 | return(0); |
| 663 | } |
| 664 | |
| 665 | /* Timer method called to reset stopped watchdogs-- |
| 666 | * because of the PLD bug on CP1400, we cannot mask |
| 667 | * interrupts within the PLD so me must continually |
| 668 | * reset the timers ad infinitum. |
| 669 | */ |
| 670 | static void wd_brokentimer(unsigned long data) |
| 671 | { |
| 672 | struct wd_device* pDev = (struct wd_device*)data; |
| 673 | int id, tripped = 0; |
| 674 | |
| 675 | /* kill a running timer instance, in case we |
| 676 | * were called directly instead of by kernel timer |
| 677 | */ |
| 678 | if(timer_pending(&wd_timer)) { |
| 679 | del_timer(&wd_timer); |
| 680 | } |
| 681 | |
| 682 | for(id = WD0_ID; id < WD_NUMDEVS; ++id) { |
| 683 | if(pDev->watchdog[id].runstatus & WD_STAT_BSTOP) { |
| 684 | ++tripped; |
| 685 | wd_resetbrokentimer(&pDev->watchdog[id]); |
| 686 | } |
| 687 | } |
| 688 | |
| 689 | if(tripped) { |
| 690 | /* there is at least one timer brokenstopped-- reschedule */ |
| 691 | init_timer(&wd_timer); |
| 692 | wd_timer.expires = WD_BTIMEOUT; |
| 693 | add_timer(&wd_timer); |
| 694 | } |
| 695 | } |
| 696 | |
| 697 | static int wd_getstatus(struct wd_timer* pTimer) |
| 698 | { |
| 699 | unsigned char stat = wd_readb(pTimer->regs + WD_STATUS); |
| 700 | unsigned char intr = wd_readb(wd_dev.regs + PLD_IMASK); |
| 701 | unsigned char ret = WD_STOPPED; |
| 702 | |
| 703 | /* determine STOPPED */ |
| 704 | if(0 == stat ) { |
| 705 | return(ret); |
| 706 | } |
| 707 | /* determine EXPIRED vs FREERUN vs RUNNING */ |
| 708 | else if(WD_S_EXPIRED & stat) { |
| 709 | ret = WD_EXPIRED; |
| 710 | } |
| 711 | else if(WD_S_RUNNING & stat) { |
| 712 | if(intr & pTimer->intr_mask) { |
| 713 | ret = WD_FREERUN; |
| 714 | } |
| 715 | else { |
| 716 | /* Fudge WD_EXPIRED status for defective CP1400-- |
| 717 | * IF timer is running |
| 718 | * AND brokenstop is set |
| 719 | * AND an interrupt has been serviced |
| 720 | * we are WD_EXPIRED. |
| 721 | * |
| 722 | * IF timer is running |
| 723 | * AND brokenstop is set |
| 724 | * AND no interrupt has been serviced |
| 725 | * we are WD_FREERUN. |
| 726 | */ |
| 727 | if(wd_dev.isbaddoggie && (pTimer->runstatus & WD_STAT_BSTOP)) { |
| 728 | if(pTimer->runstatus & WD_STAT_SVCD) { |
| 729 | ret = WD_EXPIRED; |
| 730 | } |
| 731 | else { |
| 732 | /* we could as well pretend we are expired */ |
| 733 | ret = WD_FREERUN; |
| 734 | } |
| 735 | } |
| 736 | else { |
| 737 | ret = WD_RUNNING; |
| 738 | } |
| 739 | } |
| 740 | } |
| 741 | |
| 742 | /* determine SERVICED */ |
| 743 | if(pTimer->runstatus & WD_STAT_SVCD) { |
| 744 | ret |= WD_SERVICED; |
| 745 | } |
| 746 | |
| 747 | return(ret); |
| 748 | } |
| 749 | |
| 750 | static int __init wd_init(void) |
| 751 | { |
| 752 | int id; |
| 753 | struct linux_ebus *ebus = NULL; |
| 754 | struct linux_ebus_device *edev = NULL; |
| 755 | |
| 756 | for_each_ebus(ebus) { |
| 757 | for_each_ebusdev(edev, ebus) { |
| 758 | if (!strcmp(edev->prom_name, WD_OBPNAME)) |
| 759 | goto ebus_done; |
| 760 | } |
| 761 | } |
| 762 | |
| 763 | ebus_done: |
| 764 | if(!edev) { |
| 765 | printk("%s: unable to locate device\n", WD_OBPNAME); |
| 766 | return -ENODEV; |
| 767 | } |
| 768 | |
| 769 | wd_dev.regs = |
| 770 | ioremap(edev->resource[0].start, 4 * WD_TIMER_REGSZ); /* ? */ |
| 771 | |
| 772 | if(NULL == wd_dev.regs) { |
| 773 | printk("%s: unable to map registers\n", WD_OBPNAME); |
| 774 | return(-ENODEV); |
| 775 | } |
| 776 | |
| 777 | /* initialize device structure from OBP parameters */ |
| 778 | wd_dev.irq = edev->irqs[0]; |
| 779 | wd_dev.opt_enable = wd_opt_enable(); |
| 780 | wd_dev.opt_reboot = wd_opt_reboot(); |
| 781 | wd_dev.opt_timeout = wd_opt_timeout(); |
| 782 | wd_dev.isbaddoggie = wd_isbroken(); |
| 783 | |
| 784 | /* disable all interrupts unless watchdog-enabled? == true */ |
| 785 | if(! wd_dev.opt_enable) { |
| 786 | wd_toggleintr(NULL, WD_INTR_OFF); |
| 787 | } |
| 788 | |
| 789 | /* register miscellaneous devices */ |
| 790 | for(id = WD0_ID; id < WD_NUMDEVS; ++id) { |
| 791 | if(0 != wd_inittimer(id)) { |
| 792 | printk("%s%i: unable to initialize\n", WD_OBPNAME, id); |
| 793 | } |
| 794 | } |
| 795 | |
| 796 | /* warn about possible defective PLD */ |
| 797 | if(wd_dev.isbaddoggie) { |
| 798 | init_timer(&wd_timer); |
| 799 | wd_timer.function = wd_brokentimer; |
| 800 | wd_timer.data = (unsigned long)&wd_dev; |
| 801 | wd_timer.expires = WD_BTIMEOUT; |
| 802 | |
| 803 | printk("%s: PLD defect workaround enabled for model %s\n", |
| 804 | WD_OBPNAME, WD_BADMODEL); |
| 805 | } |
| 806 | return(0); |
| 807 | } |
| 808 | |
| 809 | static void __exit wd_cleanup(void) |
| 810 | { |
| 811 | int id; |
| 812 | |
| 813 | /* if 'watchdog-enable?' == TRUE, timers are not stopped |
| 814 | * when module is unloaded. All brokenstopped timers will |
| 815 | * also now eventually trip. |
| 816 | */ |
| 817 | for(id = WD0_ID; id < WD_NUMDEVS; ++id) { |
| 818 | if(WD_S_RUNNING == wd_readb(wd_dev.watchdog[id].regs + WD_STATUS)) { |
| 819 | if(wd_dev.opt_enable) { |
| 820 | printk(KERN_WARNING "%s%i: timer not stopped at release\n", |
| 821 | WD_OBPNAME, id); |
| 822 | } |
| 823 | else { |
| 824 | wd_stoptimer(&wd_dev.watchdog[id]); |
| 825 | if(wd_dev.watchdog[id].runstatus & WD_STAT_BSTOP) { |
| 826 | wd_resetbrokentimer(&wd_dev.watchdog[id]); |
| 827 | printk(KERN_WARNING |
| 828 | "%s%i: defect workaround disabled at release, "\ |
| 829 | "timer expires in ~%01i sec\n", |
| 830 | WD_OBPNAME, id, |
| 831 | wd_readw(wd_dev.watchdog[id].regs + WD_LIMIT) / 10); |
| 832 | } |
| 833 | } |
| 834 | } |
| 835 | } |
| 836 | |
| 837 | if(wd_dev.isbaddoggie && timer_pending(&wd_timer)) { |
| 838 | del_timer(&wd_timer); |
| 839 | } |
| 840 | if(0 != (wd_dev.watchdog[WD0_ID].runstatus & WD_STAT_INIT)) { |
| 841 | misc_deregister(&wd0_miscdev); |
| 842 | } |
| 843 | if(0 != (wd_dev.watchdog[WD1_ID].runstatus & WD_STAT_INIT)) { |
| 844 | misc_deregister(&wd1_miscdev); |
| 845 | } |
| 846 | if(0 != (wd_dev.watchdog[WD2_ID].runstatus & WD_STAT_INIT)) { |
| 847 | misc_deregister(&wd2_miscdev); |
| 848 | } |
| 849 | if(0 != wd_dev.initialized) { |
| 850 | free_irq(wd_dev.irq, (void *)wd_dev.regs); |
| 851 | } |
| 852 | iounmap(wd_dev.regs); |
| 853 | } |
| 854 | |
| 855 | module_init(wd_init); |
| 856 | module_exit(wd_cleanup); |