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1// SPDX-License-Identifier: GPL-2.0+2/*3 * sch311x_wdt.c - Driver for the SCH311x Super-I/O chips4 * integrated watchdog.5 *6 * (c) Copyright 2008 Wim Van Sebroeck <wim@iguana.be>.7 *8 * Neither Wim Van Sebroeck nor Iguana vzw. admit liability nor9 * provide warranty for any of this software. This material is10 * provided "AS-IS" and at no charge.11 */12 13/*14 * Includes, defines, variables, module parameters, ...15 */16 17#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt18 19/* Includes */20#include <linux/module.h> /* For module specific items */21#include <linux/moduleparam.h> /* For new moduleparam's */22#include <linux/types.h> /* For standard types (like size_t) */23#include <linux/errno.h> /* For the -ENODEV/... values */24#include <linux/kernel.h> /* For printk/... */25#include <linux/miscdevice.h> /* For struct miscdevice */26#include <linux/watchdog.h> /* For the watchdog specific items */27#include <linux/init.h> /* For __init/__exit/... */28#include <linux/fs.h> /* For file operations */29#include <linux/platform_device.h> /* For platform_driver framework */30#include <linux/ioport.h> /* For io-port access */31#include <linux/spinlock.h> /* For spin_lock/spin_unlock/... */32#include <linux/uaccess.h> /* For copy_to_user/put_user/... */33#include <linux/io.h> /* For inb/outb/... */34 35/* Module and version information */36#define DRV_NAME "sch311x_wdt"37 38/* Runtime registers */39#define GP60 0x4740#define WDT_TIME_OUT 0x6541#define WDT_VAL 0x6642#define WDT_CFG 0x6743#define WDT_CTRL 0x6844 45/* internal variables */46static unsigned long sch311x_wdt_is_open;47static char sch311x_wdt_expect_close;48static struct platform_device *sch311x_wdt_pdev;49 50static int sch311x_ioports[] = { 0x2e, 0x4e, 0x162e, 0x164e, 0x00 };51 52static struct { /* The devices private data */53 /* the Runtime Register base address */54 unsigned short runtime_reg;55 /* The card's boot status */56 int boot_status;57 /* the lock for io operations */58 spinlock_t io_lock;59} sch311x_wdt_data;60 61/* Module load parameters */62static unsigned short force_id;63module_param(force_id, ushort, 0);64MODULE_PARM_DESC(force_id, "Override the detected device ID");65 66#define WATCHDOG_TIMEOUT 60 /* 60 sec default timeout */67static int timeout = WATCHDOG_TIMEOUT; /* in seconds */68module_param(timeout, int, 0);69MODULE_PARM_DESC(timeout,70 "Watchdog timeout in seconds. 1<= timeout <=15300, default="71 __MODULE_STRING(WATCHDOG_TIMEOUT) ".");72 73static bool nowayout = WATCHDOG_NOWAYOUT;74module_param(nowayout, bool, 0);75MODULE_PARM_DESC(nowayout,76 "Watchdog cannot be stopped once started (default="77 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");78 79/*80 * Super-IO functions81 */82 83static inline void sch311x_sio_enter(int sio_config_port)84{85 outb(0x55, sio_config_port);86}87 88static inline void sch311x_sio_exit(int sio_config_port)89{90 outb(0xaa, sio_config_port);91}92 93static inline int sch311x_sio_inb(int sio_config_port, int reg)94{95 outb(reg, sio_config_port);96 return inb(sio_config_port + 1);97}98 99static inline void sch311x_sio_outb(int sio_config_port, int reg, int val)100{101 outb(reg, sio_config_port);102 outb(val, sio_config_port + 1);103}104 105/*106 * Watchdog Operations107 */108 109static void sch311x_wdt_set_timeout(int t)110{111 unsigned char timeout_unit = 0x80;112 113 /* When new timeout is bigger then 255 seconds, we will use minutes */114 if (t > 255) {115 timeout_unit = 0;116 t /= 60;117 }118 119 /* -- Watchdog Timeout --120 * Bit 0-6 (Reserved)121 * Bit 7 WDT Time-out Value Units Select122 * (0 = Minutes, 1 = Seconds)123 */124 outb(timeout_unit, sch311x_wdt_data.runtime_reg + WDT_TIME_OUT);125 126 /* -- Watchdog Timer Time-out Value --127 * Bit 0-7 Binary coded units (0=Disabled, 1..255)128 */129 outb(t, sch311x_wdt_data.runtime_reg + WDT_VAL);130}131 132static void sch311x_wdt_start(void)133{134 unsigned char t;135 136 spin_lock(&sch311x_wdt_data.io_lock);137 138 /* set watchdog's timeout */139 sch311x_wdt_set_timeout(timeout);140 /* enable the watchdog */141 /* -- General Purpose I/O Bit 6.0 --142 * Bit 0, In/Out: 0 = Output, 1 = Input143 * Bit 1, Polarity: 0 = No Invert, 1 = Invert144 * Bit 2-3, Function select: 00 = GPI/O, 01 = LED1, 11 = WDT,145 * 10 = Either Edge Triggered Intr.4146 * Bit 4-6 (Reserved)147 * Bit 7, Output Type: 0 = Push Pull Bit, 1 = Open Drain148 */149 t = inb(sch311x_wdt_data.runtime_reg + GP60);150 outb((t & ~0x0d) | 0x0c, sch311x_wdt_data.runtime_reg + GP60);151 152 spin_unlock(&sch311x_wdt_data.io_lock);153 154}155 156static void sch311x_wdt_stop(void)157{158 unsigned char t;159 160 spin_lock(&sch311x_wdt_data.io_lock);161 162 /* stop the watchdog */163 t = inb(sch311x_wdt_data.runtime_reg + GP60);164 outb((t & ~0x0d) | 0x01, sch311x_wdt_data.runtime_reg + GP60);165 /* disable timeout by setting it to 0 */166 sch311x_wdt_set_timeout(0);167 168 spin_unlock(&sch311x_wdt_data.io_lock);169}170 171static void sch311x_wdt_keepalive(void)172{173 spin_lock(&sch311x_wdt_data.io_lock);174 sch311x_wdt_set_timeout(timeout);175 spin_unlock(&sch311x_wdt_data.io_lock);176}177 178static int sch311x_wdt_set_heartbeat(int t)179{180 if (t < 1 || t > (255*60))181 return -EINVAL;182 183 /* When new timeout is bigger then 255 seconds,184 * we will round up to minutes (with a max of 255) */185 if (t > 255)186 t = (((t - 1) / 60) + 1) * 60;187 188 timeout = t;189 return 0;190}191 192static void sch311x_wdt_get_status(int *status)193{194 unsigned char new_status;195 196 *status = 0;197 198 spin_lock(&sch311x_wdt_data.io_lock);199 200 /* -- Watchdog timer control --201 * Bit 0 Status Bit: 0 = Timer counting, 1 = Timeout occurred202 * Bit 1 Reserved203 * Bit 2 Force Timeout: 1 = Forces WD timeout event (self-cleaning)204 * Bit 3 P20 Force Timeout enabled:205 * 0 = P20 activity does not generate the WD timeout event206 * 1 = P20 Allows rising edge of P20, from the keyboard207 * controller, to force the WD timeout event.208 * Bit 4-7 Reserved209 */210 new_status = inb(sch311x_wdt_data.runtime_reg + WDT_CTRL);211 if (new_status & 0x01)212 *status |= WDIOF_CARDRESET;213 214 spin_unlock(&sch311x_wdt_data.io_lock);215}216 217/*218 * /dev/watchdog handling219 */220 221static ssize_t sch311x_wdt_write(struct file *file, const char __user *buf,222 size_t count, loff_t *ppos)223{224 if (count) {225 if (!nowayout) {226 size_t i;227 228 sch311x_wdt_expect_close = 0;229 230 for (i = 0; i != count; i++) {231 char c;232 if (get_user(c, buf + i))233 return -EFAULT;234 if (c == 'V')235 sch311x_wdt_expect_close = 42;236 }237 }238 sch311x_wdt_keepalive();239 }240 return count;241}242 243static long sch311x_wdt_ioctl(struct file *file, unsigned int cmd,244 unsigned long arg)245{246 int status;247 int new_timeout;248 void __user *argp = (void __user *)arg;249 int __user *p = argp;250 static const struct watchdog_info ident = {251 .options = WDIOF_KEEPALIVEPING |252 WDIOF_SETTIMEOUT |253 WDIOF_MAGICCLOSE,254 .firmware_version = 1,255 .identity = DRV_NAME,256 };257 258 switch (cmd) {259 case WDIOC_GETSUPPORT:260 if (copy_to_user(argp, &ident, sizeof(ident)))261 return -EFAULT;262 break;263 264 case WDIOC_GETSTATUS:265 {266 sch311x_wdt_get_status(&status);267 return put_user(status, p);268 }269 case WDIOC_GETBOOTSTATUS:270 return put_user(sch311x_wdt_data.boot_status, p);271 272 case WDIOC_SETOPTIONS:273 {274 int options, retval = -EINVAL;275 276 if (get_user(options, p))277 return -EFAULT;278 if (options & WDIOS_DISABLECARD) {279 sch311x_wdt_stop();280 retval = 0;281 }282 if (options & WDIOS_ENABLECARD) {283 sch311x_wdt_start();284 retval = 0;285 }286 return retval;287 }288 case WDIOC_KEEPALIVE:289 sch311x_wdt_keepalive();290 break;291 292 case WDIOC_SETTIMEOUT:293 if (get_user(new_timeout, p))294 return -EFAULT;295 if (sch311x_wdt_set_heartbeat(new_timeout))296 return -EINVAL;297 sch311x_wdt_keepalive();298 fallthrough;299 case WDIOC_GETTIMEOUT:300 return put_user(timeout, p);301 default:302 return -ENOTTY;303 }304 return 0;305}306 307static int sch311x_wdt_open(struct inode *inode, struct file *file)308{309 if (test_and_set_bit(0, &sch311x_wdt_is_open))310 return -EBUSY;311 /*312 * Activate313 */314 sch311x_wdt_start();315 return stream_open(inode, file);316}317 318static int sch311x_wdt_close(struct inode *inode, struct file *file)319{320 if (sch311x_wdt_expect_close == 42) {321 sch311x_wdt_stop();322 } else {323 pr_crit("Unexpected close, not stopping watchdog!\n");324 sch311x_wdt_keepalive();325 }326 clear_bit(0, &sch311x_wdt_is_open);327 sch311x_wdt_expect_close = 0;328 return 0;329}330 331/*332 * Kernel Interfaces333 */334 335static const struct file_operations sch311x_wdt_fops = {336 .owner = THIS_MODULE,337 .write = sch311x_wdt_write,338 .unlocked_ioctl = sch311x_wdt_ioctl,339 .compat_ioctl = compat_ptr_ioctl,340 .open = sch311x_wdt_open,341 .release = sch311x_wdt_close,342};343 344static struct miscdevice sch311x_wdt_miscdev = {345 .minor = WATCHDOG_MINOR,346 .name = "watchdog",347 .fops = &sch311x_wdt_fops,348};349 350/*351 * Init & exit routines352 */353 354static int sch311x_wdt_probe(struct platform_device *pdev)355{356 struct device *dev = &pdev->dev;357 int err;358 359 spin_lock_init(&sch311x_wdt_data.io_lock);360 361 if (!request_region(sch311x_wdt_data.runtime_reg + GP60, 1, DRV_NAME)) {362 dev_err(dev, "Failed to request region 0x%04x-0x%04x.\n",363 sch311x_wdt_data.runtime_reg + GP60,364 sch311x_wdt_data.runtime_reg + GP60);365 err = -EBUSY;366 goto exit;367 }368 369 if (!request_region(sch311x_wdt_data.runtime_reg + WDT_TIME_OUT, 4,370 DRV_NAME)) {371 dev_err(dev, "Failed to request region 0x%04x-0x%04x.\n",372 sch311x_wdt_data.runtime_reg + WDT_TIME_OUT,373 sch311x_wdt_data.runtime_reg + WDT_CTRL);374 err = -EBUSY;375 goto exit_release_region;376 }377 378 /* Make sure that the watchdog is not running */379 sch311x_wdt_stop();380 381 /* Disable keyboard and mouse interaction and interrupt */382 /* -- Watchdog timer configuration --383 * Bit 0 Reserved384 * Bit 1 Keyboard enable: 0* = No Reset, 1 = Reset WDT upon KBD Intr.385 * Bit 2 Mouse enable: 0* = No Reset, 1 = Reset WDT upon Mouse Intr386 * Bit 3 Reserved387 * Bit 4-7 WDT Interrupt Mapping: (0000* = Disabled,388 * 0001=IRQ1, 0010=(Invalid), 0011=IRQ3 to 1111=IRQ15)389 */390 outb(0, sch311x_wdt_data.runtime_reg + WDT_CFG);391 392 /* Check that the heartbeat value is within it's range ;393 * if not reset to the default */394 if (sch311x_wdt_set_heartbeat(timeout)) {395 sch311x_wdt_set_heartbeat(WATCHDOG_TIMEOUT);396 dev_info(dev, "timeout value must be 1<=x<=15300, using %d\n",397 timeout);398 }399 400 /* Get status at boot */401 sch311x_wdt_get_status(&sch311x_wdt_data.boot_status);402 403 sch311x_wdt_miscdev.parent = dev;404 405 err = misc_register(&sch311x_wdt_miscdev);406 if (err != 0) {407 dev_err(dev, "cannot register miscdev on minor=%d (err=%d)\n",408 WATCHDOG_MINOR, err);409 goto exit_release_region2;410 }411 412 dev_info(dev,413 "SMSC SCH311x WDT initialized. timeout=%d sec (nowayout=%d)\n",414 timeout, nowayout);415 416 return 0;417 418exit_release_region2:419 release_region(sch311x_wdt_data.runtime_reg + WDT_TIME_OUT, 4);420exit_release_region:421 release_region(sch311x_wdt_data.runtime_reg + GP60, 1);422 sch311x_wdt_data.runtime_reg = 0;423exit:424 return err;425}426 427static void sch311x_wdt_remove(struct platform_device *pdev)428{429 /* Stop the timer before we leave */430 if (!nowayout)431 sch311x_wdt_stop();432 433 /* Deregister */434 misc_deregister(&sch311x_wdt_miscdev);435 release_region(sch311x_wdt_data.runtime_reg + WDT_TIME_OUT, 4);436 release_region(sch311x_wdt_data.runtime_reg + GP60, 1);437 sch311x_wdt_data.runtime_reg = 0;438}439 440static void sch311x_wdt_shutdown(struct platform_device *dev)441{442 /* Turn the WDT off if we have a soft shutdown */443 sch311x_wdt_stop();444}445 446static struct platform_driver sch311x_wdt_driver = {447 .probe = sch311x_wdt_probe,448 .remove_new = sch311x_wdt_remove,449 .shutdown = sch311x_wdt_shutdown,450 .driver = {451 .name = DRV_NAME,452 },453};454 455static int __init sch311x_detect(int sio_config_port, unsigned short *addr)456{457 int err = 0, reg;458 unsigned short base_addr;459 unsigned char dev_id;460 461 sch311x_sio_enter(sio_config_port);462 463 /* Check device ID. We currently know about:464 * SCH3112 (0x7c), SCH3114 (0x7d), and SCH3116 (0x7f). */465 reg = force_id ? force_id : sch311x_sio_inb(sio_config_port, 0x20);466 if (!(reg == 0x7c || reg == 0x7d || reg == 0x7f)) {467 err = -ENODEV;468 goto exit;469 }470 dev_id = reg == 0x7c ? 2 : reg == 0x7d ? 4 : 6;471 472 /* Select logical device A (runtime registers) */473 sch311x_sio_outb(sio_config_port, 0x07, 0x0a);474 475 /* Check if Logical Device Register is currently active */476 if ((sch311x_sio_inb(sio_config_port, 0x30) & 0x01) == 0)477 pr_info("Seems that LDN 0x0a is not active...\n");478 479 /* Get the base address of the runtime registers */480 base_addr = (sch311x_sio_inb(sio_config_port, 0x60) << 8) |481 sch311x_sio_inb(sio_config_port, 0x61);482 if (!base_addr) {483 pr_err("Base address not set\n");484 err = -ENODEV;485 goto exit;486 }487 *addr = base_addr;488 489 pr_info("Found an SMSC SCH311%d chip at 0x%04x\n", dev_id, base_addr);490 491exit:492 sch311x_sio_exit(sio_config_port);493 return err;494}495 496static int __init sch311x_wdt_init(void)497{498 int err, i, found = 0;499 unsigned short addr = 0;500 501 for (i = 0; !found && sch311x_ioports[i]; i++)502 if (sch311x_detect(sch311x_ioports[i], &addr) == 0)503 found++;504 505 if (!found)506 return -ENODEV;507 508 sch311x_wdt_data.runtime_reg = addr;509 510 err = platform_driver_register(&sch311x_wdt_driver);511 if (err)512 return err;513 514 sch311x_wdt_pdev = platform_device_register_simple(DRV_NAME, addr,515 NULL, 0);516 517 if (IS_ERR(sch311x_wdt_pdev)) {518 err = PTR_ERR(sch311x_wdt_pdev);519 goto unreg_platform_driver;520 }521 522 return 0;523 524unreg_platform_driver:525 platform_driver_unregister(&sch311x_wdt_driver);526 return err;527}528 529static void __exit sch311x_wdt_exit(void)530{531 platform_device_unregister(sch311x_wdt_pdev);532 platform_driver_unregister(&sch311x_wdt_driver);533}534 535module_init(sch311x_wdt_init);536module_exit(sch311x_wdt_exit);537 538MODULE_AUTHOR("Wim Van Sebroeck <wim@iguana.be>");539MODULE_DESCRIPTION("SMSC SCH311x WatchDog Timer Driver");540MODULE_LICENSE("GPL");541