Bryan Wu | 1e6d320 | 2007-07-15 02:50:02 +0800 | [diff] [blame] | 1 | /* |
| 2 | * Blackfin On-Chip Watchdog Driver |
Bryan Wu | 1e6d320 | 2007-07-15 02:50:02 +0800 | [diff] [blame] | 3 | * |
| 4 | * Originally based on softdog.c |
Mike Frysinger | 3dae93e | 2010-02-15 19:32:25 -0500 | [diff] [blame] | 5 | * Copyright 2006-2010 Analog Devices Inc. |
Bryan Wu | 1e6d320 | 2007-07-15 02:50:02 +0800 | [diff] [blame] | 6 | * Copyright 2006-2007 Michele d'Amico |
Alan Cox | 29fa058 | 2008-10-27 15:17:56 +0000 | [diff] [blame] | 7 | * Copyright 1996 Alan Cox <alan@lxorguk.ukuu.org.uk> |
Bryan Wu | 1e6d320 | 2007-07-15 02:50:02 +0800 | [diff] [blame] | 8 | * |
| 9 | * Enter bugs at http://blackfin.uclinux.org/ |
| 10 | * |
| 11 | * Licensed under the GPL-2 or later. |
| 12 | */ |
| 13 | |
Joe Perches | 27c766a | 2012-02-15 15:06:19 -0800 | [diff] [blame] | 14 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
| 15 | |
Bryan Wu | 1e6d320 | 2007-07-15 02:50:02 +0800 | [diff] [blame] | 16 | #include <linux/platform_device.h> |
| 17 | #include <linux/module.h> |
| 18 | #include <linux/moduleparam.h> |
| 19 | #include <linux/types.h> |
| 20 | #include <linux/timer.h> |
| 21 | #include <linux/miscdevice.h> |
| 22 | #include <linux/watchdog.h> |
| 23 | #include <linux/fs.h> |
Bryan Wu | 1e6d320 | 2007-07-15 02:50:02 +0800 | [diff] [blame] | 24 | #include <linux/init.h> |
| 25 | #include <linux/interrupt.h> |
Alan Cox | 9a5f50d | 2008-05-19 14:06:30 +0100 | [diff] [blame] | 26 | #include <linux/uaccess.h> |
Wim Van Sebroeck | 089ab07 | 2008-07-15 11:46:11 +0000 | [diff] [blame] | 27 | #include <asm/blackfin.h> |
Mike Frysinger | 42bd5d4 | 2010-03-09 11:07:40 -0500 | [diff] [blame] | 28 | #include <asm/bfin_watchdog.h> |
Bryan Wu | 1e6d320 | 2007-07-15 02:50:02 +0800 | [diff] [blame] | 29 | |
Wim Van Sebroeck | a77dba7 | 2009-04-14 20:20:07 +0000 | [diff] [blame] | 30 | #define stamp(fmt, args...) \ |
| 31 | pr_debug("%s:%i: " fmt "\n", __func__, __LINE__, ## args) |
Bryan Wu | 1e6d320 | 2007-07-15 02:50:02 +0800 | [diff] [blame] | 32 | #define stampit() stamp("here i am") |
| 33 | |
| 34 | #define WATCHDOG_NAME "bfin-wdt" |
Bryan Wu | 1e6d320 | 2007-07-15 02:50:02 +0800 | [diff] [blame] | 35 | |
| 36 | /* The BF561 has two watchdogs (one per core), but since Linux |
| 37 | * only runs on core A, we'll just work with that one. |
| 38 | */ |
| 39 | #ifdef BF561_FAMILY |
| 40 | # define bfin_read_WDOG_CTL() bfin_read_WDOGA_CTL() |
| 41 | # define bfin_read_WDOG_CNT() bfin_read_WDOGA_CNT() |
| 42 | # define bfin_read_WDOG_STAT() bfin_read_WDOGA_STAT() |
| 43 | # define bfin_write_WDOG_CTL(x) bfin_write_WDOGA_CTL(x) |
| 44 | # define bfin_write_WDOG_CNT(x) bfin_write_WDOGA_CNT(x) |
| 45 | # define bfin_write_WDOG_STAT(x) bfin_write_WDOGA_STAT(x) |
| 46 | #endif |
| 47 | |
Bryan Wu | 1e6d320 | 2007-07-15 02:50:02 +0800 | [diff] [blame] | 48 | /* some defaults */ |
| 49 | #define WATCHDOG_TIMEOUT 20 |
| 50 | |
| 51 | static unsigned int timeout = WATCHDOG_TIMEOUT; |
Wim Van Sebroeck | 86a1e18 | 2012-03-05 16:51:11 +0100 | [diff] [blame] | 52 | static bool nowayout = WATCHDOG_NOWAYOUT; |
Wim Van Sebroeck | 42747d7 | 2009-12-26 18:55:22 +0000 | [diff] [blame] | 53 | static const struct watchdog_info bfin_wdt_info; |
Bryan Wu | 1e6d320 | 2007-07-15 02:50:02 +0800 | [diff] [blame] | 54 | static unsigned long open_check; |
| 55 | static char expect_close; |
Jiri Slaby | bf6350a | 2007-11-10 05:58:44 +0100 | [diff] [blame] | 56 | static DEFINE_SPINLOCK(bfin_wdt_spinlock); |
Bryan Wu | 1e6d320 | 2007-07-15 02:50:02 +0800 | [diff] [blame] | 57 | |
| 58 | /** |
| 59 | * bfin_wdt_keepalive - Keep the Userspace Watchdog Alive |
| 60 | * |
Wim Van Sebroeck | 5f3b275 | 2011-02-23 20:04:38 +0000 | [diff] [blame] | 61 | * The Userspace watchdog got a KeepAlive: schedule the next timeout. |
Bryan Wu | 1e6d320 | 2007-07-15 02:50:02 +0800 | [diff] [blame] | 62 | */ |
| 63 | static int bfin_wdt_keepalive(void) |
| 64 | { |
| 65 | stampit(); |
| 66 | bfin_write_WDOG_STAT(0); |
| 67 | return 0; |
| 68 | } |
| 69 | |
| 70 | /** |
| 71 | * bfin_wdt_stop - Stop the Watchdog |
| 72 | * |
| 73 | * Stops the on-chip watchdog. |
| 74 | */ |
| 75 | static int bfin_wdt_stop(void) |
| 76 | { |
| 77 | stampit(); |
| 78 | bfin_write_WDOG_CTL(WDEN_DISABLE); |
| 79 | return 0; |
| 80 | } |
| 81 | |
| 82 | /** |
| 83 | * bfin_wdt_start - Start the Watchdog |
| 84 | * |
| 85 | * Starts the on-chip watchdog. Automatically loads WDOG_CNT |
| 86 | * into WDOG_STAT for us. |
| 87 | */ |
| 88 | static int bfin_wdt_start(void) |
| 89 | { |
| 90 | stampit(); |
| 91 | bfin_write_WDOG_CTL(WDEN_ENABLE | ICTL_RESET); |
| 92 | return 0; |
| 93 | } |
| 94 | |
| 95 | /** |
| 96 | * bfin_wdt_running - Check Watchdog status |
| 97 | * |
| 98 | * See if the watchdog is running. |
| 99 | */ |
| 100 | static int bfin_wdt_running(void) |
| 101 | { |
| 102 | stampit(); |
| 103 | return ((bfin_read_WDOG_CTL() & WDEN_MASK) != WDEN_DISABLE); |
| 104 | } |
| 105 | |
| 106 | /** |
| 107 | * bfin_wdt_set_timeout - Set the Userspace Watchdog timeout |
| 108 | * @t: new timeout value (in seconds) |
| 109 | * |
| 110 | * Translate the specified timeout in seconds into System Clock |
| 111 | * terms which is what the on-chip Watchdog requires. |
| 112 | */ |
| 113 | static int bfin_wdt_set_timeout(unsigned long t) |
| 114 | { |
Mike Frysinger | 3dae93e | 2010-02-15 19:32:25 -0500 | [diff] [blame] | 115 | u32 cnt, max_t, sclk; |
Bryan Wu | 1e6d320 | 2007-07-15 02:50:02 +0800 | [diff] [blame] | 116 | unsigned long flags; |
| 117 | |
Mike Frysinger | 3dae93e | 2010-02-15 19:32:25 -0500 | [diff] [blame] | 118 | sclk = get_sclk(); |
| 119 | max_t = -1 / sclk; |
| 120 | cnt = t * sclk; |
| 121 | stamp("maxtimeout=%us newtimeout=%lus (cnt=%#x)", max_t, t, cnt); |
Bryan Wu | 1e6d320 | 2007-07-15 02:50:02 +0800 | [diff] [blame] | 122 | |
Mike Frysinger | 3dae93e | 2010-02-15 19:32:25 -0500 | [diff] [blame] | 123 | if (t > max_t) { |
Joe Perches | 27c766a | 2012-02-15 15:06:19 -0800 | [diff] [blame] | 124 | pr_warn("timeout value is too large\n"); |
Bryan Wu | 1e6d320 | 2007-07-15 02:50:02 +0800 | [diff] [blame] | 125 | return -EINVAL; |
| 126 | } |
| 127 | |
| 128 | spin_lock_irqsave(&bfin_wdt_spinlock, flags); |
| 129 | { |
| 130 | int run = bfin_wdt_running(); |
| 131 | bfin_wdt_stop(); |
| 132 | bfin_write_WDOG_CNT(cnt); |
Alan Cox | 9a5f50d | 2008-05-19 14:06:30 +0100 | [diff] [blame] | 133 | if (run) |
| 134 | bfin_wdt_start(); |
Bryan Wu | 1e6d320 | 2007-07-15 02:50:02 +0800 | [diff] [blame] | 135 | } |
| 136 | spin_unlock_irqrestore(&bfin_wdt_spinlock, flags); |
| 137 | |
| 138 | timeout = t; |
| 139 | |
| 140 | return 0; |
| 141 | } |
| 142 | |
| 143 | /** |
| 144 | * bfin_wdt_open - Open the Device |
| 145 | * @inode: inode of device |
| 146 | * @file: file handle of device |
| 147 | * |
| 148 | * Watchdog device is opened and started. |
| 149 | */ |
| 150 | static int bfin_wdt_open(struct inode *inode, struct file *file) |
| 151 | { |
| 152 | stampit(); |
| 153 | |
| 154 | if (test_and_set_bit(0, &open_check)) |
| 155 | return -EBUSY; |
| 156 | |
| 157 | if (nowayout) |
| 158 | __module_get(THIS_MODULE); |
| 159 | |
| 160 | bfin_wdt_keepalive(); |
| 161 | bfin_wdt_start(); |
| 162 | |
| 163 | return nonseekable_open(inode, file); |
| 164 | } |
| 165 | |
| 166 | /** |
| 167 | * bfin_wdt_close - Close the Device |
| 168 | * @inode: inode of device |
| 169 | * @file: file handle of device |
| 170 | * |
| 171 | * Watchdog device is closed and stopped. |
| 172 | */ |
| 173 | static int bfin_wdt_release(struct inode *inode, struct file *file) |
| 174 | { |
| 175 | stampit(); |
| 176 | |
Alan Cox | 9a5f50d | 2008-05-19 14:06:30 +0100 | [diff] [blame] | 177 | if (expect_close == 42) |
Bryan Wu | 1e6d320 | 2007-07-15 02:50:02 +0800 | [diff] [blame] | 178 | bfin_wdt_stop(); |
Alan Cox | 9a5f50d | 2008-05-19 14:06:30 +0100 | [diff] [blame] | 179 | else { |
Joe Perches | 27c766a | 2012-02-15 15:06:19 -0800 | [diff] [blame] | 180 | pr_crit("Unexpected close, not stopping watchdog!\n"); |
Bryan Wu | 1e6d320 | 2007-07-15 02:50:02 +0800 | [diff] [blame] | 181 | bfin_wdt_keepalive(); |
| 182 | } |
Bryan Wu | 1e6d320 | 2007-07-15 02:50:02 +0800 | [diff] [blame] | 183 | expect_close = 0; |
| 184 | clear_bit(0, &open_check); |
Bryan Wu | 1e6d320 | 2007-07-15 02:50:02 +0800 | [diff] [blame] | 185 | return 0; |
| 186 | } |
| 187 | |
| 188 | /** |
| 189 | * bfin_wdt_write - Write to Device |
| 190 | * @file: file handle of device |
| 191 | * @buf: buffer to write |
| 192 | * @count: length of buffer |
| 193 | * @ppos: offset |
| 194 | * |
| 195 | * Pings the watchdog on write. |
| 196 | */ |
| 197 | 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] | 198 | size_t len, loff_t *ppos) |
Bryan Wu | 1e6d320 | 2007-07-15 02:50:02 +0800 | [diff] [blame] | 199 | { |
| 200 | stampit(); |
| 201 | |
| 202 | if (len) { |
| 203 | if (!nowayout) { |
| 204 | size_t i; |
| 205 | |
| 206 | /* In case it was set long ago */ |
| 207 | expect_close = 0; |
| 208 | |
| 209 | for (i = 0; i != len; i++) { |
| 210 | char c; |
| 211 | if (get_user(c, data + i)) |
| 212 | return -EFAULT; |
| 213 | if (c == 'V') |
| 214 | expect_close = 42; |
| 215 | } |
| 216 | } |
| 217 | bfin_wdt_keepalive(); |
| 218 | } |
| 219 | |
| 220 | return len; |
| 221 | } |
| 222 | |
| 223 | /** |
| 224 | * bfin_wdt_ioctl - Query Device |
Bryan Wu | 1e6d320 | 2007-07-15 02:50:02 +0800 | [diff] [blame] | 225 | * @file: file handle of device |
| 226 | * @cmd: watchdog command |
| 227 | * @arg: argument |
| 228 | * |
| 229 | * Query basic information from the device or ping it, as outlined by the |
| 230 | * watchdog API. |
| 231 | */ |
Alan Cox | 9a5f50d | 2008-05-19 14:06:30 +0100 | [diff] [blame] | 232 | static long bfin_wdt_ioctl(struct file *file, |
| 233 | unsigned int cmd, unsigned long arg) |
Bryan Wu | 1e6d320 | 2007-07-15 02:50:02 +0800 | [diff] [blame] | 234 | { |
| 235 | void __user *argp = (void __user *)arg; |
| 236 | int __user *p = argp; |
| 237 | |
| 238 | stampit(); |
| 239 | |
| 240 | switch (cmd) { |
Alan Cox | 9a5f50d | 2008-05-19 14:06:30 +0100 | [diff] [blame] | 241 | case WDIOC_GETSUPPORT: |
| 242 | if (copy_to_user(argp, &bfin_wdt_info, sizeof(bfin_wdt_info))) |
| 243 | return -EFAULT; |
| 244 | else |
Bryan Wu | 1e6d320 | 2007-07-15 02:50:02 +0800 | [diff] [blame] | 245 | return 0; |
Alan Cox | 9a5f50d | 2008-05-19 14:06:30 +0100 | [diff] [blame] | 246 | case WDIOC_GETSTATUS: |
| 247 | case WDIOC_GETBOOTSTATUS: |
| 248 | return put_user(!!(_bfin_swrst & SWRST_RESET_WDOG), p); |
Alan Cox | 9a5f50d | 2008-05-19 14:06:30 +0100 | [diff] [blame] | 249 | case WDIOC_SETOPTIONS: { |
| 250 | unsigned long flags; |
| 251 | int options, ret = -EINVAL; |
Bryan Wu | 1e6d320 | 2007-07-15 02:50:02 +0800 | [diff] [blame] | 252 | |
Alan Cox | 9a5f50d | 2008-05-19 14:06:30 +0100 | [diff] [blame] | 253 | if (get_user(options, p)) |
| 254 | return -EFAULT; |
Bryan Wu | 1e6d320 | 2007-07-15 02:50:02 +0800 | [diff] [blame] | 255 | |
Alan Cox | 9a5f50d | 2008-05-19 14:06:30 +0100 | [diff] [blame] | 256 | spin_lock_irqsave(&bfin_wdt_spinlock, flags); |
| 257 | if (options & WDIOS_DISABLECARD) { |
| 258 | bfin_wdt_stop(); |
| 259 | ret = 0; |
Bryan Wu | 1e6d320 | 2007-07-15 02:50:02 +0800 | [diff] [blame] | 260 | } |
Alan Cox | 9a5f50d | 2008-05-19 14:06:30 +0100 | [diff] [blame] | 261 | if (options & WDIOS_ENABLECARD) { |
| 262 | bfin_wdt_start(); |
| 263 | ret = 0; |
Bryan Wu | 1e6d320 | 2007-07-15 02:50:02 +0800 | [diff] [blame] | 264 | } |
Alan Cox | 9a5f50d | 2008-05-19 14:06:30 +0100 | [diff] [blame] | 265 | spin_unlock_irqrestore(&bfin_wdt_spinlock, flags); |
| 266 | return ret; |
| 267 | } |
Wim Van Sebroeck | 0c06090 | 2008-07-18 11:41:17 +0000 | [diff] [blame] | 268 | case WDIOC_KEEPALIVE: |
| 269 | bfin_wdt_keepalive(); |
| 270 | return 0; |
| 271 | case WDIOC_SETTIMEOUT: { |
| 272 | int new_timeout; |
| 273 | |
| 274 | if (get_user(new_timeout, p)) |
| 275 | return -EFAULT; |
| 276 | if (bfin_wdt_set_timeout(new_timeout)) |
| 277 | return -EINVAL; |
| 278 | } |
| 279 | /* Fall */ |
| 280 | case WDIOC_GETTIMEOUT: |
| 281 | return put_user(timeout, p); |
Alan Cox | 9a5f50d | 2008-05-19 14:06:30 +0100 | [diff] [blame] | 282 | default: |
| 283 | return -ENOTTY; |
Bryan Wu | 1e6d320 | 2007-07-15 02:50:02 +0800 | [diff] [blame] | 284 | } |
| 285 | } |
| 286 | |
Bryan Wu | 1e6d320 | 2007-07-15 02:50:02 +0800 | [diff] [blame] | 287 | #ifdef CONFIG_PM |
| 288 | static int state_before_suspend; |
| 289 | |
| 290 | /** |
| 291 | * bfin_wdt_suspend - suspend the watchdog |
| 292 | * @pdev: device being suspended |
| 293 | * @state: requested suspend state |
| 294 | * |
| 295 | * Remember if the watchdog was running and stop it. |
| 296 | * TODO: is this even right? Doesn't seem to be any |
| 297 | * standard in the watchdog world ... |
| 298 | */ |
| 299 | static int bfin_wdt_suspend(struct platform_device *pdev, pm_message_t state) |
| 300 | { |
| 301 | stampit(); |
| 302 | |
| 303 | state_before_suspend = bfin_wdt_running(); |
| 304 | bfin_wdt_stop(); |
| 305 | |
| 306 | return 0; |
| 307 | } |
| 308 | |
| 309 | /** |
| 310 | * bfin_wdt_resume - resume the watchdog |
| 311 | * @pdev: device being resumed |
| 312 | * |
| 313 | * If the watchdog was running, turn it back on. |
| 314 | */ |
| 315 | static int bfin_wdt_resume(struct platform_device *pdev) |
| 316 | { |
| 317 | stampit(); |
| 318 | |
| 319 | if (state_before_suspend) { |
| 320 | bfin_wdt_set_timeout(timeout); |
| 321 | bfin_wdt_start(); |
| 322 | } |
| 323 | |
| 324 | return 0; |
| 325 | } |
| 326 | #else |
| 327 | # define bfin_wdt_suspend NULL |
| 328 | # define bfin_wdt_resume NULL |
| 329 | #endif |
| 330 | |
Jan Engelhardt | b47a166 | 2008-01-22 20:48:10 +0100 | [diff] [blame] | 331 | static const struct file_operations bfin_wdt_fops = { |
Alan Cox | 9a5f50d | 2008-05-19 14:06:30 +0100 | [diff] [blame] | 332 | .owner = THIS_MODULE, |
| 333 | .llseek = no_llseek, |
Wim Van Sebroeck | 5f3b275 | 2011-02-23 20:04:38 +0000 | [diff] [blame] | 334 | .write = bfin_wdt_write, |
Alan Cox | 9a5f50d | 2008-05-19 14:06:30 +0100 | [diff] [blame] | 335 | .unlocked_ioctl = bfin_wdt_ioctl, |
| 336 | .open = bfin_wdt_open, |
| 337 | .release = bfin_wdt_release, |
Bryan Wu | 1e6d320 | 2007-07-15 02:50:02 +0800 | [diff] [blame] | 338 | }; |
| 339 | |
| 340 | static struct miscdevice bfin_wdt_miscdev = { |
| 341 | .minor = WATCHDOG_MINOR, |
| 342 | .name = "watchdog", |
| 343 | .fops = &bfin_wdt_fops, |
| 344 | }; |
| 345 | |
Wim Van Sebroeck | 42747d7 | 2009-12-26 18:55:22 +0000 | [diff] [blame] | 346 | static const struct watchdog_info bfin_wdt_info = { |
Bryan Wu | 1e6d320 | 2007-07-15 02:50:02 +0800 | [diff] [blame] | 347 | .identity = "Blackfin Watchdog", |
| 348 | .options = WDIOF_SETTIMEOUT | |
Alan Cox | 9a5f50d | 2008-05-19 14:06:30 +0100 | [diff] [blame] | 349 | WDIOF_KEEPALIVEPING | |
| 350 | WDIOF_MAGICCLOSE, |
Bryan Wu | 1e6d320 | 2007-07-15 02:50:02 +0800 | [diff] [blame] | 351 | }; |
| 352 | |
Bryan Wu | 1e6d320 | 2007-07-15 02:50:02 +0800 | [diff] [blame] | 353 | /** |
Mike Frysinger | 93539b1 | 2008-03-27 11:53:32 -0700 | [diff] [blame] | 354 | * bfin_wdt_probe - Initialize module |
| 355 | * |
Wim Van Sebroeck | 168b525 | 2009-12-26 19:13:00 +0000 | [diff] [blame] | 356 | * Registers the misc device. Actual device |
Mike Frysinger | 93539b1 | 2008-03-27 11:53:32 -0700 | [diff] [blame] | 357 | * initialization is handled by bfin_wdt_open(). |
| 358 | */ |
Bill Pemberton | 2d991a1 | 2012-11-19 13:21:41 -0500 | [diff] [blame] | 359 | static int bfin_wdt_probe(struct platform_device *pdev) |
Mike Frysinger | 93539b1 | 2008-03-27 11:53:32 -0700 | [diff] [blame] | 360 | { |
| 361 | int ret; |
| 362 | |
Mike Frysinger | 93539b1 | 2008-03-27 11:53:32 -0700 | [diff] [blame] | 363 | ret = misc_register(&bfin_wdt_miscdev); |
| 364 | if (ret) { |
Joe Perches | 27c766a | 2012-02-15 15:06:19 -0800 | [diff] [blame] | 365 | pr_err("cannot register miscdev on minor=%d (err=%d)\n", |
| 366 | WATCHDOG_MINOR, ret); |
Mike Frysinger | 93539b1 | 2008-03-27 11:53:32 -0700 | [diff] [blame] | 367 | return ret; |
| 368 | } |
| 369 | |
Joe Perches | 27c766a | 2012-02-15 15:06:19 -0800 | [diff] [blame] | 370 | pr_info("initialized: timeout=%d sec (nowayout=%d)\n", |
| 371 | timeout, nowayout); |
Mike Frysinger | 93539b1 | 2008-03-27 11:53:32 -0700 | [diff] [blame] | 372 | |
| 373 | return 0; |
| 374 | } |
| 375 | |
| 376 | /** |
| 377 | * bfin_wdt_remove - Initialize module |
| 378 | * |
Wim Van Sebroeck | 168b525 | 2009-12-26 19:13:00 +0000 | [diff] [blame] | 379 | * Unregisters the misc device. Actual device |
Mike Frysinger | 93539b1 | 2008-03-27 11:53:32 -0700 | [diff] [blame] | 380 | * deinitialization is handled by bfin_wdt_close(). |
| 381 | */ |
Bill Pemberton | 4b12b89 | 2012-11-19 13:26:24 -0500 | [diff] [blame] | 382 | static int bfin_wdt_remove(struct platform_device *pdev) |
Mike Frysinger | 93539b1 | 2008-03-27 11:53:32 -0700 | [diff] [blame] | 383 | { |
| 384 | misc_deregister(&bfin_wdt_miscdev); |
Mike Frysinger | 93539b1 | 2008-03-27 11:53:32 -0700 | [diff] [blame] | 385 | return 0; |
| 386 | } |
| 387 | |
Wim Van Sebroeck | 168b525 | 2009-12-26 19:13:00 +0000 | [diff] [blame] | 388 | /** |
| 389 | * bfin_wdt_shutdown - Soft Shutdown Handler |
| 390 | * |
| 391 | * Handles the soft shutdown event. |
| 392 | */ |
| 393 | static void bfin_wdt_shutdown(struct platform_device *pdev) |
| 394 | { |
| 395 | stampit(); |
| 396 | |
| 397 | bfin_wdt_stop(); |
| 398 | } |
| 399 | |
Mike Frysinger | 93539b1 | 2008-03-27 11:53:32 -0700 | [diff] [blame] | 400 | static struct platform_device *bfin_wdt_device; |
| 401 | |
| 402 | static struct platform_driver bfin_wdt_driver = { |
| 403 | .probe = bfin_wdt_probe, |
Bill Pemberton | 8226871 | 2012-11-19 13:21:12 -0500 | [diff] [blame] | 404 | .remove = bfin_wdt_remove, |
Wim Van Sebroeck | 168b525 | 2009-12-26 19:13:00 +0000 | [diff] [blame] | 405 | .shutdown = bfin_wdt_shutdown, |
Mike Frysinger | 93539b1 | 2008-03-27 11:53:32 -0700 | [diff] [blame] | 406 | .suspend = bfin_wdt_suspend, |
| 407 | .resume = bfin_wdt_resume, |
| 408 | .driver = { |
| 409 | .name = WATCHDOG_NAME, |
| 410 | .owner = THIS_MODULE, |
| 411 | }, |
| 412 | }; |
| 413 | |
| 414 | /** |
Bryan Wu | 1e6d320 | 2007-07-15 02:50:02 +0800 | [diff] [blame] | 415 | * bfin_wdt_init - Initialize module |
| 416 | * |
Mike Frysinger | 93539b1 | 2008-03-27 11:53:32 -0700 | [diff] [blame] | 417 | * Checks the module params and registers the platform device & driver. |
| 418 | * Real work is in the platform probe function. |
Bryan Wu | 1e6d320 | 2007-07-15 02:50:02 +0800 | [diff] [blame] | 419 | */ |
| 420 | static int __init bfin_wdt_init(void) |
| 421 | { |
| 422 | int ret; |
| 423 | |
| 424 | stampit(); |
| 425 | |
| 426 | /* Check that the timeout value is within range */ |
| 427 | if (bfin_wdt_set_timeout(timeout)) |
| 428 | return -EINVAL; |
| 429 | |
| 430 | /* Since this is an on-chip device and needs no board-specific |
| 431 | * resources, we'll handle all the platform device stuff here. |
| 432 | */ |
Mike Frysinger | 93539b1 | 2008-03-27 11:53:32 -0700 | [diff] [blame] | 433 | ret = platform_driver_register(&bfin_wdt_driver); |
Bryan Wu | 1e6d320 | 2007-07-15 02:50:02 +0800 | [diff] [blame] | 434 | if (ret) { |
Joe Perches | 27c766a | 2012-02-15 15:06:19 -0800 | [diff] [blame] | 435 | pr_err("unable to register driver\n"); |
Bryan Wu | 1e6d320 | 2007-07-15 02:50:02 +0800 | [diff] [blame] | 436 | return ret; |
| 437 | } |
| 438 | |
Wim Van Sebroeck | a77dba7 | 2009-04-14 20:20:07 +0000 | [diff] [blame] | 439 | bfin_wdt_device = platform_device_register_simple(WATCHDOG_NAME, |
| 440 | -1, NULL, 0); |
Mike Frysinger | 93539b1 | 2008-03-27 11:53:32 -0700 | [diff] [blame] | 441 | if (IS_ERR(bfin_wdt_device)) { |
Joe Perches | 27c766a | 2012-02-15 15:06:19 -0800 | [diff] [blame] | 442 | pr_err("unable to register device\n"); |
Mike Frysinger | 93539b1 | 2008-03-27 11:53:32 -0700 | [diff] [blame] | 443 | platform_driver_unregister(&bfin_wdt_driver); |
| 444 | return PTR_ERR(bfin_wdt_device); |
Bryan Wu | 1e6d320 | 2007-07-15 02:50:02 +0800 | [diff] [blame] | 445 | } |
| 446 | |
Bryan Wu | 1e6d320 | 2007-07-15 02:50:02 +0800 | [diff] [blame] | 447 | return 0; |
| 448 | } |
| 449 | |
| 450 | /** |
| 451 | * bfin_wdt_exit - Deinitialize module |
| 452 | * |
Mike Frysinger | 93539b1 | 2008-03-27 11:53:32 -0700 | [diff] [blame] | 453 | * Back out the platform device & driver steps. Real work is in the |
| 454 | * platform remove function. |
Bryan Wu | 1e6d320 | 2007-07-15 02:50:02 +0800 | [diff] [blame] | 455 | */ |
| 456 | static void __exit bfin_wdt_exit(void) |
| 457 | { |
Mike Frysinger | 93539b1 | 2008-03-27 11:53:32 -0700 | [diff] [blame] | 458 | platform_device_unregister(bfin_wdt_device); |
| 459 | platform_driver_unregister(&bfin_wdt_driver); |
Bryan Wu | 1e6d320 | 2007-07-15 02:50:02 +0800 | [diff] [blame] | 460 | } |
| 461 | |
| 462 | module_init(bfin_wdt_init); |
| 463 | module_exit(bfin_wdt_exit); |
| 464 | |
| 465 | MODULE_AUTHOR("Michele d'Amico, Mike Frysinger <vapier@gentoo.org>"); |
| 466 | MODULE_DESCRIPTION("Blackfin Watchdog Device Driver"); |
| 467 | MODULE_LICENSE("GPL"); |
Bryan Wu | 1e6d320 | 2007-07-15 02:50:02 +0800 | [diff] [blame] | 468 | |
| 469 | module_param(timeout, uint, 0); |
Alan Cox | 9a5f50d | 2008-05-19 14:06:30 +0100 | [diff] [blame] | 470 | MODULE_PARM_DESC(timeout, |
| 471 | "Watchdog timeout in seconds. (1<=timeout<=((2^32)/SCLK), default=" |
| 472 | __MODULE_STRING(WATCHDOG_TIMEOUT) ")"); |
Bryan Wu | 1e6d320 | 2007-07-15 02:50:02 +0800 | [diff] [blame] | 473 | |
Wim Van Sebroeck | 86a1e18 | 2012-03-05 16:51:11 +0100 | [diff] [blame] | 474 | module_param(nowayout, bool, 0); |
Alan Cox | 9a5f50d | 2008-05-19 14:06:30 +0100 | [diff] [blame] | 475 | MODULE_PARM_DESC(nowayout, |
| 476 | "Watchdog cannot be stopped once started (default=" |
| 477 | __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); |