Kevin Strasser | e51c288 | 2013-06-23 21:00:06 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Kontron PLD watchdog driver |
| 3 | * |
| 4 | * Copyright (c) 2010-2013 Kontron Europe GmbH |
| 5 | * Author: Michael Brunner <michael.brunner@kontron.com> |
| 6 | * |
| 7 | * This program is free software; you can redistribute it and/or modify |
| 8 | * it under the terms of the GNU General Public License 2 as published |
| 9 | * by the Free Software Foundation. |
| 10 | * |
| 11 | * This program is distributed in the hope that it will be useful, |
| 12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 14 | * GNU General Public License for more details. |
| 15 | * |
| 16 | * Note: From the PLD watchdog point of view timeout and pretimeout are |
| 17 | * defined differently than in the kernel. |
| 18 | * First the pretimeout stage runs out before the timeout stage gets |
| 19 | * active. |
| 20 | * |
| 21 | * Kernel/API: P-----| pretimeout |
| 22 | * |-----------------------T timeout |
| 23 | * Watchdog: |-----------------P pretimeout_stage |
| 24 | * |-----T timeout_stage |
| 25 | */ |
| 26 | |
| 27 | #include <linux/module.h> |
| 28 | #include <linux/moduleparam.h> |
| 29 | #include <linux/miscdevice.h> |
| 30 | #include <linux/uaccess.h> |
| 31 | #include <linux/watchdog.h> |
| 32 | #include <linux/platform_device.h> |
| 33 | #include <linux/mfd/kempld.h> |
| 34 | |
| 35 | #define KEMPLD_WDT_STAGE_TIMEOUT(x) (0x1b + (x) * 4) |
| 36 | #define KEMPLD_WDT_STAGE_CFG(x) (0x18 + (x)) |
| 37 | #define STAGE_CFG_GET_PRESCALER(x) (((x) & 0x30) >> 4) |
Jingoo Han | 4c4e456 | 2013-09-23 19:16:57 +0900 | [diff] [blame] | 38 | #define STAGE_CFG_SET_PRESCALER(x) (((x) & 0x3) << 4) |
Kevin Strasser | e51c288 | 2013-06-23 21:00:06 -0700 | [diff] [blame] | 39 | #define STAGE_CFG_PRESCALER_MASK 0x30 |
| 40 | #define STAGE_CFG_ACTION_MASK 0x7 |
| 41 | #define STAGE_CFG_ASSERT (1 << 3) |
| 42 | |
| 43 | #define KEMPLD_WDT_MAX_STAGES 2 |
| 44 | #define KEMPLD_WDT_KICK 0x16 |
| 45 | #define KEMPLD_WDT_CFG 0x17 |
| 46 | #define KEMPLD_WDT_CFG_ENABLE 0x10 |
| 47 | #define KEMPLD_WDT_CFG_ENABLE_LOCK 0x8 |
| 48 | #define KEMPLD_WDT_CFG_GLOBAL_LOCK 0x80 |
| 49 | |
| 50 | enum { |
| 51 | ACTION_NONE = 0, |
| 52 | ACTION_RESET, |
| 53 | ACTION_NMI, |
| 54 | ACTION_SMI, |
| 55 | ACTION_SCI, |
| 56 | ACTION_DELAY, |
| 57 | }; |
| 58 | |
| 59 | enum { |
| 60 | STAGE_TIMEOUT = 0, |
| 61 | STAGE_PRETIMEOUT, |
| 62 | }; |
| 63 | |
| 64 | enum { |
| 65 | PRESCALER_21 = 0, |
| 66 | PRESCALER_17, |
| 67 | PRESCALER_12, |
| 68 | }; |
| 69 | |
Jingoo Han | b3970bd | 2013-08-01 14:39:46 +0900 | [diff] [blame] | 70 | static const u32 kempld_prescaler[] = { |
Kevin Strasser | e51c288 | 2013-06-23 21:00:06 -0700 | [diff] [blame] | 71 | [PRESCALER_21] = (1 << 21) - 1, |
| 72 | [PRESCALER_17] = (1 << 17) - 1, |
| 73 | [PRESCALER_12] = (1 << 12) - 1, |
| 74 | 0, |
| 75 | }; |
| 76 | |
| 77 | struct kempld_wdt_stage { |
| 78 | unsigned int id; |
| 79 | u32 mask; |
| 80 | }; |
| 81 | |
| 82 | struct kempld_wdt_data { |
| 83 | struct kempld_device_data *pld; |
| 84 | struct watchdog_device wdd; |
| 85 | unsigned int pretimeout; |
| 86 | struct kempld_wdt_stage stage[KEMPLD_WDT_MAX_STAGES]; |
| 87 | #ifdef CONFIG_PM |
| 88 | u8 pm_status_store; |
| 89 | #endif |
| 90 | }; |
| 91 | |
| 92 | #define DEFAULT_TIMEOUT 30 /* seconds */ |
| 93 | #define DEFAULT_PRETIMEOUT 0 |
| 94 | |
| 95 | static unsigned int timeout = DEFAULT_TIMEOUT; |
| 96 | module_param(timeout, uint, 0); |
| 97 | MODULE_PARM_DESC(timeout, |
| 98 | "Watchdog timeout in seconds. (>=0, default=" |
| 99 | __MODULE_STRING(DEFAULT_TIMEOUT) ")"); |
| 100 | |
| 101 | static unsigned int pretimeout = DEFAULT_PRETIMEOUT; |
| 102 | module_param(pretimeout, uint, 0); |
| 103 | MODULE_PARM_DESC(pretimeout, |
| 104 | "Watchdog pretimeout in seconds. (>=0, default=" |
| 105 | __MODULE_STRING(DEFAULT_PRETIMEOUT) ")"); |
| 106 | |
| 107 | static bool nowayout = WATCHDOG_NOWAYOUT; |
| 108 | module_param(nowayout, bool, 0); |
| 109 | MODULE_PARM_DESC(nowayout, |
| 110 | "Watchdog cannot be stopped once started (default=" |
| 111 | __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); |
| 112 | |
| 113 | static int kempld_wdt_set_stage_action(struct kempld_wdt_data *wdt_data, |
| 114 | struct kempld_wdt_stage *stage, |
| 115 | u8 action) |
| 116 | { |
| 117 | struct kempld_device_data *pld = wdt_data->pld; |
| 118 | u8 stage_cfg; |
| 119 | |
| 120 | if (!stage || !stage->mask) |
| 121 | return -EINVAL; |
| 122 | |
| 123 | kempld_get_mutex(pld); |
| 124 | stage_cfg = kempld_read8(pld, KEMPLD_WDT_STAGE_CFG(stage->id)); |
| 125 | stage_cfg &= ~STAGE_CFG_ACTION_MASK; |
| 126 | stage_cfg |= (action & STAGE_CFG_ACTION_MASK); |
| 127 | |
| 128 | if (action == ACTION_RESET) |
| 129 | stage_cfg |= STAGE_CFG_ASSERT; |
| 130 | else |
| 131 | stage_cfg &= ~STAGE_CFG_ASSERT; |
| 132 | |
| 133 | kempld_write8(pld, KEMPLD_WDT_STAGE_CFG(stage->id), stage_cfg); |
| 134 | kempld_release_mutex(pld); |
| 135 | |
| 136 | return 0; |
| 137 | } |
| 138 | |
| 139 | static int kempld_wdt_set_stage_timeout(struct kempld_wdt_data *wdt_data, |
| 140 | struct kempld_wdt_stage *stage, |
| 141 | unsigned int timeout) |
| 142 | { |
| 143 | struct kempld_device_data *pld = wdt_data->pld; |
| 144 | u32 prescaler = kempld_prescaler[PRESCALER_21]; |
| 145 | u64 stage_timeout64; |
| 146 | u32 stage_timeout; |
| 147 | u32 remainder; |
| 148 | u8 stage_cfg; |
| 149 | |
| 150 | if (!stage) |
| 151 | return -EINVAL; |
| 152 | |
| 153 | stage_timeout64 = (u64)timeout * pld->pld_clock; |
| 154 | remainder = do_div(stage_timeout64, prescaler); |
| 155 | if (remainder) |
| 156 | stage_timeout64++; |
| 157 | |
| 158 | if (stage_timeout64 > stage->mask) |
| 159 | return -EINVAL; |
| 160 | |
| 161 | stage_timeout = stage_timeout64 & stage->mask; |
| 162 | |
| 163 | kempld_get_mutex(pld); |
| 164 | stage_cfg = kempld_read8(pld, KEMPLD_WDT_STAGE_CFG(stage->id)); |
| 165 | stage_cfg &= ~STAGE_CFG_PRESCALER_MASK; |
| 166 | stage_cfg |= STAGE_CFG_SET_PRESCALER(prescaler); |
| 167 | kempld_write8(pld, KEMPLD_WDT_STAGE_CFG(stage->id), stage_cfg); |
| 168 | kempld_write32(pld, KEMPLD_WDT_STAGE_TIMEOUT(stage->id), |
| 169 | stage_timeout); |
| 170 | kempld_release_mutex(pld); |
| 171 | |
| 172 | return 0; |
| 173 | } |
| 174 | |
| 175 | /* |
| 176 | * kempld_get_mutex must be called prior to calling this function. |
| 177 | */ |
| 178 | static unsigned int kempld_wdt_get_timeout(struct kempld_wdt_data *wdt_data, |
| 179 | struct kempld_wdt_stage *stage) |
| 180 | { |
| 181 | struct kempld_device_data *pld = wdt_data->pld; |
| 182 | unsigned int timeout; |
| 183 | u64 stage_timeout; |
| 184 | u32 prescaler; |
| 185 | u32 remainder; |
| 186 | u8 stage_cfg; |
| 187 | |
| 188 | if (!stage->mask) |
| 189 | return 0; |
| 190 | |
| 191 | stage_cfg = kempld_read8(pld, KEMPLD_WDT_STAGE_CFG(stage->id)); |
| 192 | stage_timeout = kempld_read32(pld, KEMPLD_WDT_STAGE_TIMEOUT(stage->id)); |
| 193 | prescaler = kempld_prescaler[STAGE_CFG_GET_PRESCALER(stage_cfg)]; |
| 194 | |
| 195 | stage_timeout = (stage_timeout & stage->mask) * prescaler; |
| 196 | remainder = do_div(stage_timeout, pld->pld_clock); |
| 197 | if (remainder) |
| 198 | stage_timeout++; |
| 199 | |
| 200 | timeout = stage_timeout; |
| 201 | WARN_ON_ONCE(timeout != stage_timeout); |
| 202 | |
| 203 | return timeout; |
| 204 | } |
| 205 | |
| 206 | static int kempld_wdt_set_timeout(struct watchdog_device *wdd, |
| 207 | unsigned int timeout) |
| 208 | { |
| 209 | struct kempld_wdt_data *wdt_data = watchdog_get_drvdata(wdd); |
| 210 | struct kempld_wdt_stage *pretimeout_stage; |
| 211 | struct kempld_wdt_stage *timeout_stage; |
| 212 | int ret; |
| 213 | |
| 214 | timeout_stage = &wdt_data->stage[STAGE_TIMEOUT]; |
| 215 | pretimeout_stage = &wdt_data->stage[STAGE_PRETIMEOUT]; |
| 216 | |
| 217 | if (pretimeout_stage->mask && wdt_data->pretimeout > 0) |
| 218 | timeout = wdt_data->pretimeout; |
| 219 | |
| 220 | ret = kempld_wdt_set_stage_action(wdt_data, timeout_stage, |
| 221 | ACTION_RESET); |
| 222 | if (ret) |
| 223 | return ret; |
| 224 | ret = kempld_wdt_set_stage_timeout(wdt_data, timeout_stage, |
| 225 | timeout); |
| 226 | if (ret) |
| 227 | return ret; |
| 228 | |
| 229 | wdd->timeout = timeout; |
| 230 | return 0; |
| 231 | } |
| 232 | |
| 233 | static int kempld_wdt_set_pretimeout(struct watchdog_device *wdd, |
| 234 | unsigned int pretimeout) |
| 235 | { |
| 236 | struct kempld_wdt_data *wdt_data = watchdog_get_drvdata(wdd); |
| 237 | struct kempld_wdt_stage *pretimeout_stage; |
| 238 | u8 action = ACTION_NONE; |
| 239 | int ret; |
| 240 | |
| 241 | pretimeout_stage = &wdt_data->stage[STAGE_PRETIMEOUT]; |
| 242 | |
| 243 | if (!pretimeout_stage->mask) |
| 244 | return -ENXIO; |
| 245 | |
| 246 | if (pretimeout > wdd->timeout) |
| 247 | return -EINVAL; |
| 248 | |
| 249 | if (pretimeout > 0) |
| 250 | action = ACTION_NMI; |
| 251 | |
| 252 | ret = kempld_wdt_set_stage_action(wdt_data, pretimeout_stage, |
| 253 | action); |
| 254 | if (ret) |
| 255 | return ret; |
| 256 | ret = kempld_wdt_set_stage_timeout(wdt_data, pretimeout_stage, |
| 257 | wdd->timeout - pretimeout); |
| 258 | if (ret) |
| 259 | return ret; |
| 260 | |
| 261 | wdt_data->pretimeout = pretimeout; |
| 262 | return 0; |
| 263 | } |
| 264 | |
| 265 | static void kempld_wdt_update_timeouts(struct kempld_wdt_data *wdt_data) |
| 266 | { |
| 267 | struct kempld_device_data *pld = wdt_data->pld; |
| 268 | struct kempld_wdt_stage *pretimeout_stage; |
| 269 | struct kempld_wdt_stage *timeout_stage; |
| 270 | unsigned int pretimeout, timeout; |
| 271 | |
| 272 | pretimeout_stage = &wdt_data->stage[STAGE_PRETIMEOUT]; |
| 273 | timeout_stage = &wdt_data->stage[STAGE_TIMEOUT]; |
| 274 | |
| 275 | kempld_get_mutex(pld); |
| 276 | pretimeout = kempld_wdt_get_timeout(wdt_data, pretimeout_stage); |
| 277 | timeout = kempld_wdt_get_timeout(wdt_data, timeout_stage); |
| 278 | kempld_release_mutex(pld); |
| 279 | |
| 280 | if (pretimeout) |
| 281 | wdt_data->pretimeout = timeout; |
| 282 | else |
| 283 | wdt_data->pretimeout = 0; |
| 284 | |
| 285 | wdt_data->wdd.timeout = pretimeout + timeout; |
| 286 | } |
| 287 | |
| 288 | static int kempld_wdt_start(struct watchdog_device *wdd) |
| 289 | { |
| 290 | struct kempld_wdt_data *wdt_data = watchdog_get_drvdata(wdd); |
| 291 | struct kempld_device_data *pld = wdt_data->pld; |
| 292 | u8 status; |
| 293 | int ret; |
| 294 | |
| 295 | ret = kempld_wdt_set_timeout(wdd, wdd->timeout); |
| 296 | if (ret) |
| 297 | return ret; |
| 298 | |
| 299 | kempld_get_mutex(pld); |
| 300 | status = kempld_read8(pld, KEMPLD_WDT_CFG); |
| 301 | status |= KEMPLD_WDT_CFG_ENABLE; |
| 302 | kempld_write8(pld, KEMPLD_WDT_CFG, status); |
| 303 | status = kempld_read8(pld, KEMPLD_WDT_CFG); |
| 304 | kempld_release_mutex(pld); |
| 305 | |
| 306 | /* Check if the watchdog was enabled */ |
| 307 | if (!(status & KEMPLD_WDT_CFG_ENABLE)) |
| 308 | return -EACCES; |
| 309 | |
| 310 | return 0; |
| 311 | } |
| 312 | |
| 313 | static int kempld_wdt_stop(struct watchdog_device *wdd) |
| 314 | { |
| 315 | struct kempld_wdt_data *wdt_data = watchdog_get_drvdata(wdd); |
| 316 | struct kempld_device_data *pld = wdt_data->pld; |
| 317 | u8 status; |
| 318 | |
| 319 | kempld_get_mutex(pld); |
| 320 | status = kempld_read8(pld, KEMPLD_WDT_CFG); |
| 321 | status &= ~KEMPLD_WDT_CFG_ENABLE; |
| 322 | kempld_write8(pld, KEMPLD_WDT_CFG, status); |
| 323 | status = kempld_read8(pld, KEMPLD_WDT_CFG); |
| 324 | kempld_release_mutex(pld); |
| 325 | |
| 326 | /* Check if the watchdog was disabled */ |
| 327 | if (status & KEMPLD_WDT_CFG_ENABLE) |
| 328 | return -EACCES; |
| 329 | |
| 330 | return 0; |
| 331 | } |
| 332 | |
| 333 | static int kempld_wdt_keepalive(struct watchdog_device *wdd) |
| 334 | { |
| 335 | struct kempld_wdt_data *wdt_data = watchdog_get_drvdata(wdd); |
| 336 | struct kempld_device_data *pld = wdt_data->pld; |
| 337 | |
| 338 | kempld_get_mutex(pld); |
| 339 | kempld_write8(pld, KEMPLD_WDT_KICK, 'K'); |
| 340 | kempld_release_mutex(pld); |
| 341 | |
| 342 | return 0; |
| 343 | } |
| 344 | |
| 345 | static long kempld_wdt_ioctl(struct watchdog_device *wdd, unsigned int cmd, |
| 346 | unsigned long arg) |
| 347 | { |
| 348 | struct kempld_wdt_data *wdt_data = watchdog_get_drvdata(wdd); |
| 349 | void __user *argp = (void __user *)arg; |
| 350 | int ret = -ENOIOCTLCMD; |
| 351 | int __user *p = argp; |
| 352 | int new_value; |
| 353 | |
| 354 | switch (cmd) { |
| 355 | case WDIOC_SETPRETIMEOUT: |
| 356 | if (get_user(new_value, p)) |
| 357 | return -EFAULT; |
| 358 | ret = kempld_wdt_set_pretimeout(wdd, new_value); |
| 359 | if (ret) |
| 360 | return ret; |
| 361 | ret = kempld_wdt_keepalive(wdd); |
| 362 | break; |
| 363 | case WDIOC_GETPRETIMEOUT: |
Jingoo Han | b3970bd | 2013-08-01 14:39:46 +0900 | [diff] [blame] | 364 | ret = put_user(wdt_data->pretimeout, (int __user *)arg); |
Kevin Strasser | e51c288 | 2013-06-23 21:00:06 -0700 | [diff] [blame] | 365 | break; |
| 366 | } |
| 367 | |
| 368 | return ret; |
| 369 | } |
| 370 | |
| 371 | static int kempld_wdt_probe_stages(struct watchdog_device *wdd) |
| 372 | { |
| 373 | struct kempld_wdt_data *wdt_data = watchdog_get_drvdata(wdd); |
| 374 | struct kempld_device_data *pld = wdt_data->pld; |
| 375 | struct kempld_wdt_stage *pretimeout_stage; |
| 376 | struct kempld_wdt_stage *timeout_stage; |
| 377 | u8 index, data, data_orig; |
| 378 | u32 mask; |
| 379 | int i, j; |
| 380 | |
| 381 | pretimeout_stage = &wdt_data->stage[STAGE_PRETIMEOUT]; |
| 382 | timeout_stage = &wdt_data->stage[STAGE_TIMEOUT]; |
| 383 | |
| 384 | pretimeout_stage->mask = 0; |
| 385 | timeout_stage->mask = 0; |
| 386 | |
| 387 | for (i = 0; i < 3; i++) { |
| 388 | index = KEMPLD_WDT_STAGE_TIMEOUT(i); |
| 389 | mask = 0; |
| 390 | |
| 391 | kempld_get_mutex(pld); |
| 392 | /* Probe each byte individually. */ |
| 393 | for (j = 0; j < 4; j++) { |
| 394 | data_orig = kempld_read8(pld, index + j); |
| 395 | kempld_write8(pld, index + j, 0x00); |
| 396 | data = kempld_read8(pld, index + j); |
| 397 | /* A failed write means this byte is reserved */ |
| 398 | if (data != 0x00) |
| 399 | break; |
| 400 | kempld_write8(pld, index + j, data_orig); |
| 401 | mask |= 0xff << (j * 8); |
| 402 | } |
| 403 | kempld_release_mutex(pld); |
| 404 | |
| 405 | /* Assign available stages to timeout and pretimeout */ |
| 406 | if (!timeout_stage->mask) { |
| 407 | timeout_stage->mask = mask; |
| 408 | timeout_stage->id = i; |
| 409 | } else { |
| 410 | if (pld->feature_mask & KEMPLD_FEATURE_BIT_NMI) { |
| 411 | pretimeout_stage->mask = timeout_stage->mask; |
| 412 | timeout_stage->mask = mask; |
| 413 | pretimeout_stage->id = timeout_stage->id; |
| 414 | timeout_stage->id = i; |
| 415 | } |
| 416 | break; |
| 417 | } |
| 418 | } |
| 419 | |
| 420 | if (!timeout_stage->mask) |
| 421 | return -ENODEV; |
| 422 | |
| 423 | return 0; |
| 424 | } |
| 425 | |
| 426 | static struct watchdog_info kempld_wdt_info = { |
| 427 | .identity = "KEMPLD Watchdog", |
| 428 | .options = WDIOF_SETTIMEOUT | |
| 429 | WDIOF_KEEPALIVEPING | |
| 430 | WDIOF_MAGICCLOSE | |
| 431 | WDIOF_PRETIMEOUT |
| 432 | }; |
| 433 | |
| 434 | static struct watchdog_ops kempld_wdt_ops = { |
| 435 | .owner = THIS_MODULE, |
| 436 | .start = kempld_wdt_start, |
| 437 | .stop = kempld_wdt_stop, |
| 438 | .ping = kempld_wdt_keepalive, |
| 439 | .set_timeout = kempld_wdt_set_timeout, |
| 440 | .ioctl = kempld_wdt_ioctl, |
| 441 | }; |
| 442 | |
| 443 | static int kempld_wdt_probe(struct platform_device *pdev) |
| 444 | { |
| 445 | struct kempld_device_data *pld = dev_get_drvdata(pdev->dev.parent); |
| 446 | struct kempld_wdt_data *wdt_data; |
| 447 | struct device *dev = &pdev->dev; |
| 448 | struct watchdog_device *wdd; |
| 449 | u8 status; |
| 450 | int ret = 0; |
| 451 | |
| 452 | wdt_data = devm_kzalloc(dev, sizeof(*wdt_data), GFP_KERNEL); |
| 453 | if (!wdt_data) |
| 454 | return -ENOMEM; |
| 455 | |
| 456 | wdt_data->pld = pld; |
| 457 | wdd = &wdt_data->wdd; |
| 458 | wdd->parent = dev; |
| 459 | |
| 460 | kempld_get_mutex(pld); |
| 461 | status = kempld_read8(pld, KEMPLD_WDT_CFG); |
| 462 | kempld_release_mutex(pld); |
| 463 | |
| 464 | /* Enable nowayout if watchdog is already locked */ |
| 465 | if (status & (KEMPLD_WDT_CFG_ENABLE_LOCK | |
| 466 | KEMPLD_WDT_CFG_GLOBAL_LOCK)) { |
| 467 | if (!nowayout) |
| 468 | dev_warn(dev, |
| 469 | "Forcing nowayout - watchdog lock enabled!\n"); |
| 470 | nowayout = true; |
| 471 | } |
| 472 | |
| 473 | wdd->info = &kempld_wdt_info; |
| 474 | wdd->ops = &kempld_wdt_ops; |
| 475 | |
| 476 | watchdog_set_drvdata(wdd, wdt_data); |
| 477 | watchdog_set_nowayout(wdd, nowayout); |
| 478 | |
| 479 | ret = kempld_wdt_probe_stages(wdd); |
| 480 | if (ret) |
| 481 | return ret; |
| 482 | |
| 483 | kempld_wdt_set_timeout(wdd, timeout); |
| 484 | kempld_wdt_set_pretimeout(wdd, pretimeout); |
| 485 | |
| 486 | /* Check if watchdog is already enabled */ |
| 487 | if (status & KEMPLD_WDT_CFG_ENABLE) { |
| 488 | /* Get current watchdog settings */ |
| 489 | kempld_wdt_update_timeouts(wdt_data); |
| 490 | dev_info(dev, "Watchdog was already enabled\n"); |
| 491 | } |
| 492 | |
| 493 | platform_set_drvdata(pdev, wdt_data); |
| 494 | ret = watchdog_register_device(wdd); |
| 495 | if (ret) |
| 496 | return ret; |
| 497 | |
| 498 | dev_info(dev, "Watchdog registered with %ds timeout\n", wdd->timeout); |
| 499 | |
| 500 | return 0; |
| 501 | } |
| 502 | |
| 503 | static void kempld_wdt_shutdown(struct platform_device *pdev) |
| 504 | { |
| 505 | struct kempld_wdt_data *wdt_data = platform_get_drvdata(pdev); |
| 506 | |
| 507 | kempld_wdt_stop(&wdt_data->wdd); |
| 508 | } |
| 509 | |
| 510 | static int kempld_wdt_remove(struct platform_device *pdev) |
| 511 | { |
| 512 | struct kempld_wdt_data *wdt_data = platform_get_drvdata(pdev); |
| 513 | struct watchdog_device *wdd = &wdt_data->wdd; |
| 514 | int ret = 0; |
| 515 | |
| 516 | if (!nowayout) |
| 517 | ret = kempld_wdt_stop(wdd); |
| 518 | watchdog_unregister_device(wdd); |
| 519 | |
| 520 | return ret; |
| 521 | } |
| 522 | |
| 523 | #ifdef CONFIG_PM |
| 524 | /* Disable watchdog if it is active during suspend */ |
| 525 | static int kempld_wdt_suspend(struct platform_device *pdev, |
| 526 | pm_message_t message) |
| 527 | { |
| 528 | struct kempld_wdt_data *wdt_data = platform_get_drvdata(pdev); |
| 529 | struct kempld_device_data *pld = wdt_data->pld; |
| 530 | struct watchdog_device *wdd = &wdt_data->wdd; |
| 531 | |
| 532 | kempld_get_mutex(pld); |
| 533 | wdt_data->pm_status_store = kempld_read8(pld, KEMPLD_WDT_CFG); |
| 534 | kempld_release_mutex(pld); |
| 535 | |
| 536 | kempld_wdt_update_timeouts(wdt_data); |
| 537 | |
| 538 | if (wdt_data->pm_status_store & KEMPLD_WDT_CFG_ENABLE) |
| 539 | return kempld_wdt_stop(wdd); |
| 540 | |
| 541 | return 0; |
| 542 | } |
| 543 | |
| 544 | /* Enable watchdog and configure it if necessary */ |
| 545 | static int kempld_wdt_resume(struct platform_device *pdev) |
| 546 | { |
| 547 | struct kempld_wdt_data *wdt_data = platform_get_drvdata(pdev); |
| 548 | struct watchdog_device *wdd = &wdt_data->wdd; |
| 549 | |
| 550 | /* |
| 551 | * If watchdog was stopped before suspend be sure it gets disabled |
| 552 | * again, for the case BIOS has enabled it during resume |
| 553 | */ |
| 554 | if (wdt_data->pm_status_store & KEMPLD_WDT_CFG_ENABLE) |
| 555 | return kempld_wdt_start(wdd); |
| 556 | else |
| 557 | return kempld_wdt_stop(wdd); |
| 558 | } |
| 559 | #else |
| 560 | #define kempld_wdt_suspend NULL |
| 561 | #define kempld_wdt_resume NULL |
| 562 | #endif |
| 563 | |
| 564 | static struct platform_driver kempld_wdt_driver = { |
| 565 | .driver = { |
| 566 | .name = "kempld-wdt", |
| 567 | .owner = THIS_MODULE, |
| 568 | }, |
| 569 | .probe = kempld_wdt_probe, |
| 570 | .remove = kempld_wdt_remove, |
| 571 | .shutdown = kempld_wdt_shutdown, |
| 572 | .suspend = kempld_wdt_suspend, |
| 573 | .resume = kempld_wdt_resume, |
| 574 | }; |
| 575 | |
| 576 | module_platform_driver(kempld_wdt_driver); |
| 577 | |
| 578 | MODULE_DESCRIPTION("KEM PLD Watchdog Driver"); |
| 579 | MODULE_AUTHOR("Michael Brunner <michael.brunner@kontron.com>"); |
| 580 | MODULE_LICENSE("GPL"); |