Bryan Wu | 1e6d320 | 2007-07-15 02:50:02 +0800 | [diff] [blame] | 1 | /* |
| 2 | * Blackfin On-Chip Watchdog Driver |
| 3 | * Supports BF53[123]/BF53[467]/BF54[2489]/BF561 |
| 4 | * |
| 5 | * Originally based on softdog.c |
| 6 | * Copyright 2006-2007 Analog Devices Inc. |
| 7 | * Copyright 2006-2007 Michele d'Amico |
Alan Cox | 29fa058 | 2008-10-27 15:17:56 +0000 | [diff] [blame] | 8 | * Copyright 1996 Alan Cox <alan@lxorguk.ukuu.org.uk> |
Bryan Wu | 1e6d320 | 2007-07-15 02:50:02 +0800 | [diff] [blame] | 9 | * |
| 10 | * Enter bugs at http://blackfin.uclinux.org/ |
| 11 | * |
| 12 | * Licensed under the GPL-2 or later. |
| 13 | */ |
| 14 | |
| 15 | #include <linux/platform_device.h> |
| 16 | #include <linux/module.h> |
| 17 | #include <linux/moduleparam.h> |
| 18 | #include <linux/types.h> |
| 19 | #include <linux/timer.h> |
| 20 | #include <linux/miscdevice.h> |
| 21 | #include <linux/watchdog.h> |
| 22 | #include <linux/fs.h> |
| 23 | #include <linux/notifier.h> |
| 24 | #include <linux/reboot.h> |
| 25 | #include <linux/init.h> |
| 26 | #include <linux/interrupt.h> |
Alan Cox | 9a5f50d | 2008-05-19 14:06:30 +0100 | [diff] [blame] | 27 | #include <linux/uaccess.h> |
Wim Van Sebroeck | 089ab07 | 2008-07-15 11:46:11 +0000 | [diff] [blame] | 28 | #include <asm/blackfin.h> |
Bryan Wu | 1e6d320 | 2007-07-15 02:50:02 +0800 | [diff] [blame] | 29 | |
| 30 | #define stamp(fmt, args...) pr_debug("%s:%i: " fmt "\n", __func__, __LINE__, ## args) |
| 31 | #define stampit() stamp("here i am") |
Mike Frysinger | 93539b1 | 2008-03-27 11:53:32 -0700 | [diff] [blame] | 32 | #define pr_devinit(fmt, args...) ({ static const __devinitconst char __fmt[] = fmt; printk(__fmt, ## args); }) |
| 33 | #define pr_init(fmt, args...) ({ static const __initconst char __fmt[] = fmt; printk(__fmt, ## args); }) |
Bryan Wu | 1e6d320 | 2007-07-15 02:50:02 +0800 | [diff] [blame] | 34 | |
| 35 | #define WATCHDOG_NAME "bfin-wdt" |
| 36 | #define PFX WATCHDOG_NAME ": " |
| 37 | |
| 38 | /* The BF561 has two watchdogs (one per core), but since Linux |
| 39 | * only runs on core A, we'll just work with that one. |
| 40 | */ |
| 41 | #ifdef BF561_FAMILY |
| 42 | # define bfin_read_WDOG_CTL() bfin_read_WDOGA_CTL() |
| 43 | # define bfin_read_WDOG_CNT() bfin_read_WDOGA_CNT() |
| 44 | # define bfin_read_WDOG_STAT() bfin_read_WDOGA_STAT() |
| 45 | # define bfin_write_WDOG_CTL(x) bfin_write_WDOGA_CTL(x) |
| 46 | # define bfin_write_WDOG_CNT(x) bfin_write_WDOGA_CNT(x) |
| 47 | # define bfin_write_WDOG_STAT(x) bfin_write_WDOGA_STAT(x) |
| 48 | #endif |
| 49 | |
| 50 | /* Bit in SWRST that indicates boot caused by watchdog */ |
| 51 | #define SWRST_RESET_WDOG 0x4000 |
| 52 | |
| 53 | /* Bit in WDOG_CTL that indicates watchdog has expired (WDR0) */ |
| 54 | #define WDOG_EXPIRED 0x8000 |
| 55 | |
| 56 | /* Masks for WDEV field in WDOG_CTL register */ |
| 57 | #define ICTL_RESET 0x0 |
| 58 | #define ICTL_NMI 0x2 |
| 59 | #define ICTL_GPI 0x4 |
| 60 | #define ICTL_NONE 0x6 |
| 61 | #define ICTL_MASK 0x6 |
| 62 | |
| 63 | /* Masks for WDEN field in WDOG_CTL register */ |
| 64 | #define WDEN_MASK 0x0FF0 |
| 65 | #define WDEN_ENABLE 0x0000 |
| 66 | #define WDEN_DISABLE 0x0AD0 |
| 67 | |
| 68 | /* some defaults */ |
| 69 | #define WATCHDOG_TIMEOUT 20 |
| 70 | |
| 71 | static unsigned int timeout = WATCHDOG_TIMEOUT; |
| 72 | static int nowayout = WATCHDOG_NOWAYOUT; |
| 73 | static struct watchdog_info bfin_wdt_info; |
| 74 | static unsigned long open_check; |
| 75 | static char expect_close; |
Jiri Slaby | bf6350a | 2007-11-10 05:58:44 +0100 | [diff] [blame] | 76 | static DEFINE_SPINLOCK(bfin_wdt_spinlock); |
Bryan Wu | 1e6d320 | 2007-07-15 02:50:02 +0800 | [diff] [blame] | 77 | |
| 78 | /** |
| 79 | * bfin_wdt_keepalive - Keep the Userspace Watchdog Alive |
| 80 | * |
| 81 | * The Userspace watchdog got a KeepAlive: schedule the next timeout. |
| 82 | */ |
| 83 | static int bfin_wdt_keepalive(void) |
| 84 | { |
| 85 | stampit(); |
| 86 | bfin_write_WDOG_STAT(0); |
| 87 | return 0; |
| 88 | } |
| 89 | |
| 90 | /** |
| 91 | * bfin_wdt_stop - Stop the Watchdog |
| 92 | * |
| 93 | * Stops the on-chip watchdog. |
| 94 | */ |
| 95 | static int bfin_wdt_stop(void) |
| 96 | { |
| 97 | stampit(); |
| 98 | bfin_write_WDOG_CTL(WDEN_DISABLE); |
| 99 | return 0; |
| 100 | } |
| 101 | |
| 102 | /** |
| 103 | * bfin_wdt_start - Start the Watchdog |
| 104 | * |
| 105 | * Starts the on-chip watchdog. Automatically loads WDOG_CNT |
| 106 | * into WDOG_STAT for us. |
| 107 | */ |
| 108 | static int bfin_wdt_start(void) |
| 109 | { |
| 110 | stampit(); |
| 111 | bfin_write_WDOG_CTL(WDEN_ENABLE | ICTL_RESET); |
| 112 | return 0; |
| 113 | } |
| 114 | |
| 115 | /** |
| 116 | * bfin_wdt_running - Check Watchdog status |
| 117 | * |
| 118 | * See if the watchdog is running. |
| 119 | */ |
| 120 | static int bfin_wdt_running(void) |
| 121 | { |
| 122 | stampit(); |
| 123 | return ((bfin_read_WDOG_CTL() & WDEN_MASK) != WDEN_DISABLE); |
| 124 | } |
| 125 | |
| 126 | /** |
| 127 | * bfin_wdt_set_timeout - Set the Userspace Watchdog timeout |
| 128 | * @t: new timeout value (in seconds) |
| 129 | * |
| 130 | * Translate the specified timeout in seconds into System Clock |
| 131 | * terms which is what the on-chip Watchdog requires. |
| 132 | */ |
| 133 | static int bfin_wdt_set_timeout(unsigned long t) |
| 134 | { |
| 135 | u32 cnt; |
| 136 | unsigned long flags; |
| 137 | |
| 138 | stampit(); |
| 139 | |
| 140 | cnt = t * get_sclk(); |
| 141 | if (cnt < get_sclk()) { |
| 142 | printk(KERN_WARNING PFX "timeout value is too large\n"); |
| 143 | return -EINVAL; |
| 144 | } |
| 145 | |
| 146 | spin_lock_irqsave(&bfin_wdt_spinlock, flags); |
| 147 | { |
| 148 | int run = bfin_wdt_running(); |
| 149 | bfin_wdt_stop(); |
| 150 | bfin_write_WDOG_CNT(cnt); |
Alan Cox | 9a5f50d | 2008-05-19 14:06:30 +0100 | [diff] [blame] | 151 | if (run) |
| 152 | bfin_wdt_start(); |
Bryan Wu | 1e6d320 | 2007-07-15 02:50:02 +0800 | [diff] [blame] | 153 | } |
| 154 | spin_unlock_irqrestore(&bfin_wdt_spinlock, flags); |
| 155 | |
| 156 | timeout = t; |
| 157 | |
| 158 | return 0; |
| 159 | } |
| 160 | |
| 161 | /** |
| 162 | * bfin_wdt_open - Open the Device |
| 163 | * @inode: inode of device |
| 164 | * @file: file handle of device |
| 165 | * |
| 166 | * Watchdog device is opened and started. |
| 167 | */ |
| 168 | static int bfin_wdt_open(struct inode *inode, struct file *file) |
| 169 | { |
| 170 | stampit(); |
| 171 | |
| 172 | if (test_and_set_bit(0, &open_check)) |
| 173 | return -EBUSY; |
| 174 | |
| 175 | if (nowayout) |
| 176 | __module_get(THIS_MODULE); |
| 177 | |
| 178 | bfin_wdt_keepalive(); |
| 179 | bfin_wdt_start(); |
| 180 | |
| 181 | return nonseekable_open(inode, file); |
| 182 | } |
| 183 | |
| 184 | /** |
| 185 | * bfin_wdt_close - Close the Device |
| 186 | * @inode: inode of device |
| 187 | * @file: file handle of device |
| 188 | * |
| 189 | * Watchdog device is closed and stopped. |
| 190 | */ |
| 191 | static int bfin_wdt_release(struct inode *inode, struct file *file) |
| 192 | { |
| 193 | stampit(); |
| 194 | |
Alan Cox | 9a5f50d | 2008-05-19 14:06:30 +0100 | [diff] [blame] | 195 | if (expect_close == 42) |
Bryan Wu | 1e6d320 | 2007-07-15 02:50:02 +0800 | [diff] [blame] | 196 | bfin_wdt_stop(); |
Alan Cox | 9a5f50d | 2008-05-19 14:06:30 +0100 | [diff] [blame] | 197 | else { |
| 198 | printk(KERN_CRIT PFX |
| 199 | "Unexpected close, not stopping watchdog!\n"); |
Bryan Wu | 1e6d320 | 2007-07-15 02:50:02 +0800 | [diff] [blame] | 200 | bfin_wdt_keepalive(); |
| 201 | } |
Bryan Wu | 1e6d320 | 2007-07-15 02:50:02 +0800 | [diff] [blame] | 202 | expect_close = 0; |
| 203 | clear_bit(0, &open_check); |
Bryan Wu | 1e6d320 | 2007-07-15 02:50:02 +0800 | [diff] [blame] | 204 | return 0; |
| 205 | } |
| 206 | |
| 207 | /** |
| 208 | * bfin_wdt_write - Write to Device |
| 209 | * @file: file handle of device |
| 210 | * @buf: buffer to write |
| 211 | * @count: length of buffer |
| 212 | * @ppos: offset |
| 213 | * |
| 214 | * Pings the watchdog on write. |
| 215 | */ |
| 216 | static ssize_t bfin_wdt_write(struct file *file, const char __user *data, |
Alan Cox | 9a5f50d | 2008-05-19 14:06:30 +0100 | [diff] [blame] | 217 | size_t len, loff_t *ppos) |
Bryan Wu | 1e6d320 | 2007-07-15 02:50:02 +0800 | [diff] [blame] | 218 | { |
| 219 | stampit(); |
| 220 | |
| 221 | if (len) { |
| 222 | if (!nowayout) { |
| 223 | size_t i; |
| 224 | |
| 225 | /* In case it was set long ago */ |
| 226 | expect_close = 0; |
| 227 | |
| 228 | for (i = 0; i != len; i++) { |
| 229 | char c; |
| 230 | if (get_user(c, data + i)) |
| 231 | return -EFAULT; |
| 232 | if (c == 'V') |
| 233 | expect_close = 42; |
| 234 | } |
| 235 | } |
| 236 | bfin_wdt_keepalive(); |
| 237 | } |
| 238 | |
| 239 | return len; |
| 240 | } |
| 241 | |
| 242 | /** |
| 243 | * bfin_wdt_ioctl - Query Device |
Bryan Wu | 1e6d320 | 2007-07-15 02:50:02 +0800 | [diff] [blame] | 244 | * @file: file handle of device |
| 245 | * @cmd: watchdog command |
| 246 | * @arg: argument |
| 247 | * |
| 248 | * Query basic information from the device or ping it, as outlined by the |
| 249 | * watchdog API. |
| 250 | */ |
Alan Cox | 9a5f50d | 2008-05-19 14:06:30 +0100 | [diff] [blame] | 251 | static long bfin_wdt_ioctl(struct file *file, |
| 252 | unsigned int cmd, unsigned long arg) |
Bryan Wu | 1e6d320 | 2007-07-15 02:50:02 +0800 | [diff] [blame] | 253 | { |
| 254 | void __user *argp = (void __user *)arg; |
| 255 | int __user *p = argp; |
| 256 | |
| 257 | stampit(); |
| 258 | |
| 259 | switch (cmd) { |
Alan Cox | 9a5f50d | 2008-05-19 14:06:30 +0100 | [diff] [blame] | 260 | case WDIOC_GETSUPPORT: |
| 261 | if (copy_to_user(argp, &bfin_wdt_info, sizeof(bfin_wdt_info))) |
| 262 | return -EFAULT; |
| 263 | else |
Bryan Wu | 1e6d320 | 2007-07-15 02:50:02 +0800 | [diff] [blame] | 264 | return 0; |
Alan Cox | 9a5f50d | 2008-05-19 14:06:30 +0100 | [diff] [blame] | 265 | case WDIOC_GETSTATUS: |
| 266 | case WDIOC_GETBOOTSTATUS: |
| 267 | return put_user(!!(_bfin_swrst & SWRST_RESET_WDOG), p); |
Alan Cox | 9a5f50d | 2008-05-19 14:06:30 +0100 | [diff] [blame] | 268 | case WDIOC_SETOPTIONS: { |
| 269 | unsigned long flags; |
| 270 | int options, ret = -EINVAL; |
Bryan Wu | 1e6d320 | 2007-07-15 02:50:02 +0800 | [diff] [blame] | 271 | |
Alan Cox | 9a5f50d | 2008-05-19 14:06:30 +0100 | [diff] [blame] | 272 | if (get_user(options, p)) |
| 273 | return -EFAULT; |
Bryan Wu | 1e6d320 | 2007-07-15 02:50:02 +0800 | [diff] [blame] | 274 | |
Alan Cox | 9a5f50d | 2008-05-19 14:06:30 +0100 | [diff] [blame] | 275 | spin_lock_irqsave(&bfin_wdt_spinlock, flags); |
| 276 | if (options & WDIOS_DISABLECARD) { |
| 277 | bfin_wdt_stop(); |
| 278 | ret = 0; |
Bryan Wu | 1e6d320 | 2007-07-15 02:50:02 +0800 | [diff] [blame] | 279 | } |
Alan Cox | 9a5f50d | 2008-05-19 14:06:30 +0100 | [diff] [blame] | 280 | if (options & WDIOS_ENABLECARD) { |
| 281 | bfin_wdt_start(); |
| 282 | ret = 0; |
Bryan Wu | 1e6d320 | 2007-07-15 02:50:02 +0800 | [diff] [blame] | 283 | } |
Alan Cox | 9a5f50d | 2008-05-19 14:06:30 +0100 | [diff] [blame] | 284 | spin_unlock_irqrestore(&bfin_wdt_spinlock, flags); |
| 285 | return ret; |
| 286 | } |
Wim Van Sebroeck | 0c06090 | 2008-07-18 11:41:17 +0000 | [diff] [blame] | 287 | case WDIOC_KEEPALIVE: |
| 288 | bfin_wdt_keepalive(); |
| 289 | return 0; |
| 290 | case WDIOC_SETTIMEOUT: { |
| 291 | int new_timeout; |
| 292 | |
| 293 | if (get_user(new_timeout, p)) |
| 294 | return -EFAULT; |
| 295 | if (bfin_wdt_set_timeout(new_timeout)) |
| 296 | return -EINVAL; |
| 297 | } |
| 298 | /* Fall */ |
| 299 | case WDIOC_GETTIMEOUT: |
| 300 | return put_user(timeout, p); |
Alan Cox | 9a5f50d | 2008-05-19 14:06:30 +0100 | [diff] [blame] | 301 | default: |
| 302 | return -ENOTTY; |
Bryan Wu | 1e6d320 | 2007-07-15 02:50:02 +0800 | [diff] [blame] | 303 | } |
| 304 | } |
| 305 | |
| 306 | /** |
| 307 | * bfin_wdt_notify_sys - Notifier Handler |
| 308 | * @this: notifier block |
| 309 | * @code: notifier event |
| 310 | * @unused: unused |
| 311 | * |
| 312 | * Handles specific events, such as turning off the watchdog during a |
| 313 | * shutdown event. |
| 314 | */ |
Alan Cox | 9a5f50d | 2008-05-19 14:06:30 +0100 | [diff] [blame] | 315 | static int bfin_wdt_notify_sys(struct notifier_block *this, |
| 316 | unsigned long code, void *unused) |
Bryan Wu | 1e6d320 | 2007-07-15 02:50:02 +0800 | [diff] [blame] | 317 | { |
| 318 | stampit(); |
| 319 | |
| 320 | if (code == SYS_DOWN || code == SYS_HALT) |
| 321 | bfin_wdt_stop(); |
| 322 | |
| 323 | return NOTIFY_DONE; |
| 324 | } |
| 325 | |
| 326 | #ifdef CONFIG_PM |
| 327 | static int state_before_suspend; |
| 328 | |
| 329 | /** |
| 330 | * bfin_wdt_suspend - suspend the watchdog |
| 331 | * @pdev: device being suspended |
| 332 | * @state: requested suspend state |
| 333 | * |
| 334 | * Remember if the watchdog was running and stop it. |
| 335 | * TODO: is this even right? Doesn't seem to be any |
| 336 | * standard in the watchdog world ... |
| 337 | */ |
| 338 | static int bfin_wdt_suspend(struct platform_device *pdev, pm_message_t state) |
| 339 | { |
| 340 | stampit(); |
| 341 | |
| 342 | state_before_suspend = bfin_wdt_running(); |
| 343 | bfin_wdt_stop(); |
| 344 | |
| 345 | return 0; |
| 346 | } |
| 347 | |
| 348 | /** |
| 349 | * bfin_wdt_resume - resume the watchdog |
| 350 | * @pdev: device being resumed |
| 351 | * |
| 352 | * If the watchdog was running, turn it back on. |
| 353 | */ |
| 354 | static int bfin_wdt_resume(struct platform_device *pdev) |
| 355 | { |
| 356 | stampit(); |
| 357 | |
| 358 | if (state_before_suspend) { |
| 359 | bfin_wdt_set_timeout(timeout); |
| 360 | bfin_wdt_start(); |
| 361 | } |
| 362 | |
| 363 | return 0; |
| 364 | } |
| 365 | #else |
| 366 | # define bfin_wdt_suspend NULL |
| 367 | # define bfin_wdt_resume NULL |
| 368 | #endif |
| 369 | |
Jan Engelhardt | b47a166 | 2008-01-22 20:48:10 +0100 | [diff] [blame] | 370 | static const struct file_operations bfin_wdt_fops = { |
Alan Cox | 9a5f50d | 2008-05-19 14:06:30 +0100 | [diff] [blame] | 371 | .owner = THIS_MODULE, |
| 372 | .llseek = no_llseek, |
| 373 | .write = bfin_wdt_write, |
| 374 | .unlocked_ioctl = bfin_wdt_ioctl, |
| 375 | .open = bfin_wdt_open, |
| 376 | .release = bfin_wdt_release, |
Bryan Wu | 1e6d320 | 2007-07-15 02:50:02 +0800 | [diff] [blame] | 377 | }; |
| 378 | |
| 379 | static struct miscdevice bfin_wdt_miscdev = { |
| 380 | .minor = WATCHDOG_MINOR, |
| 381 | .name = "watchdog", |
| 382 | .fops = &bfin_wdt_fops, |
| 383 | }; |
| 384 | |
| 385 | static struct watchdog_info bfin_wdt_info = { |
| 386 | .identity = "Blackfin Watchdog", |
| 387 | .options = WDIOF_SETTIMEOUT | |
Alan Cox | 9a5f50d | 2008-05-19 14:06:30 +0100 | [diff] [blame] | 388 | WDIOF_KEEPALIVEPING | |
| 389 | WDIOF_MAGICCLOSE, |
Bryan Wu | 1e6d320 | 2007-07-15 02:50:02 +0800 | [diff] [blame] | 390 | }; |
| 391 | |
| 392 | static struct notifier_block bfin_wdt_notifier = { |
| 393 | .notifier_call = bfin_wdt_notify_sys, |
| 394 | }; |
| 395 | |
| 396 | /** |
Mike Frysinger | 93539b1 | 2008-03-27 11:53:32 -0700 | [diff] [blame] | 397 | * bfin_wdt_probe - Initialize module |
| 398 | * |
| 399 | * Registers the misc device and notifier handler. Actual device |
| 400 | * initialization is handled by bfin_wdt_open(). |
| 401 | */ |
| 402 | static int __devinit bfin_wdt_probe(struct platform_device *pdev) |
| 403 | { |
| 404 | int ret; |
| 405 | |
| 406 | ret = register_reboot_notifier(&bfin_wdt_notifier); |
| 407 | if (ret) { |
Alan Cox | 9a5f50d | 2008-05-19 14:06:30 +0100 | [diff] [blame] | 408 | pr_devinit(KERN_ERR PFX |
| 409 | "cannot register reboot notifier (err=%d)\n", ret); |
Mike Frysinger | 93539b1 | 2008-03-27 11:53:32 -0700 | [diff] [blame] | 410 | return ret; |
| 411 | } |
| 412 | |
| 413 | ret = misc_register(&bfin_wdt_miscdev); |
| 414 | if (ret) { |
Alan Cox | 9a5f50d | 2008-05-19 14:06:30 +0100 | [diff] [blame] | 415 | pr_devinit(KERN_ERR PFX |
| 416 | "cannot register miscdev on minor=%d (err=%d)\n", |
| 417 | WATCHDOG_MINOR, ret); |
Mike Frysinger | 93539b1 | 2008-03-27 11:53:32 -0700 | [diff] [blame] | 418 | unregister_reboot_notifier(&bfin_wdt_notifier); |
| 419 | return ret; |
| 420 | } |
| 421 | |
| 422 | pr_devinit(KERN_INFO PFX "initialized: timeout=%d sec (nowayout=%d)\n", |
| 423 | timeout, nowayout); |
| 424 | |
| 425 | return 0; |
| 426 | } |
| 427 | |
| 428 | /** |
| 429 | * bfin_wdt_remove - Initialize module |
| 430 | * |
| 431 | * Unregisters the misc device and notifier handler. Actual device |
| 432 | * deinitialization is handled by bfin_wdt_close(). |
| 433 | */ |
| 434 | static int __devexit bfin_wdt_remove(struct platform_device *pdev) |
| 435 | { |
| 436 | misc_deregister(&bfin_wdt_miscdev); |
| 437 | unregister_reboot_notifier(&bfin_wdt_notifier); |
| 438 | return 0; |
| 439 | } |
| 440 | |
| 441 | static struct platform_device *bfin_wdt_device; |
| 442 | |
| 443 | static struct platform_driver bfin_wdt_driver = { |
| 444 | .probe = bfin_wdt_probe, |
| 445 | .remove = __devexit_p(bfin_wdt_remove), |
| 446 | .suspend = bfin_wdt_suspend, |
| 447 | .resume = bfin_wdt_resume, |
| 448 | .driver = { |
| 449 | .name = WATCHDOG_NAME, |
| 450 | .owner = THIS_MODULE, |
| 451 | }, |
| 452 | }; |
| 453 | |
| 454 | /** |
Bryan Wu | 1e6d320 | 2007-07-15 02:50:02 +0800 | [diff] [blame] | 455 | * bfin_wdt_init - Initialize module |
| 456 | * |
Mike Frysinger | 93539b1 | 2008-03-27 11:53:32 -0700 | [diff] [blame] | 457 | * Checks the module params and registers the platform device & driver. |
| 458 | * Real work is in the platform probe function. |
Bryan Wu | 1e6d320 | 2007-07-15 02:50:02 +0800 | [diff] [blame] | 459 | */ |
| 460 | static int __init bfin_wdt_init(void) |
| 461 | { |
| 462 | int ret; |
| 463 | |
| 464 | stampit(); |
| 465 | |
| 466 | /* Check that the timeout value is within range */ |
| 467 | if (bfin_wdt_set_timeout(timeout)) |
| 468 | return -EINVAL; |
| 469 | |
| 470 | /* Since this is an on-chip device and needs no board-specific |
| 471 | * resources, we'll handle all the platform device stuff here. |
| 472 | */ |
Mike Frysinger | 93539b1 | 2008-03-27 11:53:32 -0700 | [diff] [blame] | 473 | ret = platform_driver_register(&bfin_wdt_driver); |
Bryan Wu | 1e6d320 | 2007-07-15 02:50:02 +0800 | [diff] [blame] | 474 | if (ret) { |
Mike Frysinger | 93539b1 | 2008-03-27 11:53:32 -0700 | [diff] [blame] | 475 | pr_init(KERN_ERR PFX "unable to register driver\n"); |
Bryan Wu | 1e6d320 | 2007-07-15 02:50:02 +0800 | [diff] [blame] | 476 | return ret; |
| 477 | } |
| 478 | |
Mike Frysinger | 93539b1 | 2008-03-27 11:53:32 -0700 | [diff] [blame] | 479 | bfin_wdt_device = platform_device_register_simple(WATCHDOG_NAME, -1, NULL, 0); |
| 480 | if (IS_ERR(bfin_wdt_device)) { |
| 481 | pr_init(KERN_ERR PFX "unable to register device\n"); |
| 482 | platform_driver_unregister(&bfin_wdt_driver); |
| 483 | return PTR_ERR(bfin_wdt_device); |
Bryan Wu | 1e6d320 | 2007-07-15 02:50:02 +0800 | [diff] [blame] | 484 | } |
| 485 | |
Bryan Wu | 1e6d320 | 2007-07-15 02:50:02 +0800 | [diff] [blame] | 486 | return 0; |
| 487 | } |
| 488 | |
| 489 | /** |
| 490 | * bfin_wdt_exit - Deinitialize module |
| 491 | * |
Mike Frysinger | 93539b1 | 2008-03-27 11:53:32 -0700 | [diff] [blame] | 492 | * Back out the platform device & driver steps. Real work is in the |
| 493 | * platform remove function. |
Bryan Wu | 1e6d320 | 2007-07-15 02:50:02 +0800 | [diff] [blame] | 494 | */ |
| 495 | static void __exit bfin_wdt_exit(void) |
| 496 | { |
Mike Frysinger | 93539b1 | 2008-03-27 11:53:32 -0700 | [diff] [blame] | 497 | platform_device_unregister(bfin_wdt_device); |
| 498 | platform_driver_unregister(&bfin_wdt_driver); |
Bryan Wu | 1e6d320 | 2007-07-15 02:50:02 +0800 | [diff] [blame] | 499 | } |
| 500 | |
| 501 | module_init(bfin_wdt_init); |
| 502 | module_exit(bfin_wdt_exit); |
| 503 | |
| 504 | MODULE_AUTHOR("Michele d'Amico, Mike Frysinger <vapier@gentoo.org>"); |
| 505 | MODULE_DESCRIPTION("Blackfin Watchdog Device Driver"); |
| 506 | MODULE_LICENSE("GPL"); |
| 507 | MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); |
| 508 | |
| 509 | module_param(timeout, uint, 0); |
Alan Cox | 9a5f50d | 2008-05-19 14:06:30 +0100 | [diff] [blame] | 510 | MODULE_PARM_DESC(timeout, |
| 511 | "Watchdog timeout in seconds. (1<=timeout<=((2^32)/SCLK), default=" |
| 512 | __MODULE_STRING(WATCHDOG_TIMEOUT) ")"); |
Bryan Wu | 1e6d320 | 2007-07-15 02:50:02 +0800 | [diff] [blame] | 513 | |
| 514 | module_param(nowayout, int, 0); |
Alan Cox | 9a5f50d | 2008-05-19 14:06:30 +0100 | [diff] [blame] | 515 | MODULE_PARM_DESC(nowayout, |
| 516 | "Watchdog cannot be stopped once started (default=" |
| 517 | __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); |