// SPDX-License-Identifier: GPL-2.0+ /* * sch311x_wdt.c - Driver for the SCH311x Super-I/O chips * integrated watchdog. * * (c) Copyright 2008 Wim Van Sebroeck . * * Neither Wim Van Sebroeck nor Iguana vzw. admit liability nor * provide warranty for any of this software. This material is * provided "AS-IS" and at no charge. */ /* * Includes, defines, variables, module parameters, ... */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt /* Includes */ #include /* For module specific items */ #include /* For new moduleparam's */ #include /* For standard types (like size_t) */ #include /* For the -ENODEV/... values */ #include /* For printk/... */ #include /* For struct miscdevice */ #include /* For the watchdog specific items */ #include /* For __init/__exit/... */ #include /* For file operations */ #include /* For platform_driver framework */ #include /* For io-port access */ #include /* For spin_lock/spin_unlock/... */ #include /* For copy_to_user/put_user/... */ #include /* For inb/outb/... */ /* Module and version information */ #define DRV_NAME "sch311x_wdt" /* Runtime registers */ #define GP60 0x47 #define WDT_TIME_OUT 0x65 #define WDT_VAL 0x66 #define WDT_CFG 0x67 #define WDT_CTRL 0x68 /* internal variables */ static unsigned long sch311x_wdt_is_open; static char sch311x_wdt_expect_close; static struct platform_device *sch311x_wdt_pdev; static int sch311x_ioports[] = { 0x2e, 0x4e, 0x162e, 0x164e, 0x00 }; static struct { /* The devices private data */ /* the Runtime Register base address */ unsigned short runtime_reg; /* The card's boot status */ int boot_status; /* the lock for io operations */ spinlock_t io_lock; } sch311x_wdt_data; /* Module load parameters */ static unsigned short force_id; module_param(force_id, ushort, 0); MODULE_PARM_DESC(force_id, "Override the detected device ID"); #define WATCHDOG_TIMEOUT 60 /* 60 sec default timeout */ static int timeout = WATCHDOG_TIMEOUT; /* in seconds */ module_param(timeout, int, 0); MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds. 1<= timeout <=15300, default=" __MODULE_STRING(WATCHDOG_TIMEOUT) "."); static bool nowayout = WATCHDOG_NOWAYOUT; module_param(nowayout, bool, 0); MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); /* * Super-IO functions */ static inline void sch311x_sio_enter(int sio_config_port) { outb(0x55, sio_config_port); } static inline void sch311x_sio_exit(int sio_config_port) { outb(0xaa, sio_config_port); } static inline int sch311x_sio_inb(int sio_config_port, int reg) { outb(reg, sio_config_port); return inb(sio_config_port + 1); } static inline void sch311x_sio_outb(int sio_config_port, int reg, int val) { outb(reg, sio_config_port); outb(val, sio_config_port + 1); } /* * Watchdog Operations */ static void sch311x_wdt_set_timeout(int t) { unsigned char timeout_unit = 0x80; /* When new timeout is bigger then 255 seconds, we will use minutes */ if (t > 255) { timeout_unit = 0; t /= 60; } /* -- Watchdog Timeout -- * Bit 0-6 (Reserved) * Bit 7 WDT Time-out Value Units Select * (0 = Minutes, 1 = Seconds) */ outb(timeout_unit, sch311x_wdt_data.runtime_reg + WDT_TIME_OUT); /* -- Watchdog Timer Time-out Value -- * Bit 0-7 Binary coded units (0=Disabled, 1..255) */ outb(t, sch311x_wdt_data.runtime_reg + WDT_VAL); } static void sch311x_wdt_start(void) { unsigned char t; spin_lock(&sch311x_wdt_data.io_lock); /* set watchdog's timeout */ sch311x_wdt_set_timeout(timeout); /* enable the watchdog */ /* -- General Purpose I/O Bit 6.0 -- * Bit 0, In/Out: 0 = Output, 1 = Input * Bit 1, Polarity: 0 = No Invert, 1 = Invert * Bit 2-3, Function select: 00 = GPI/O, 01 = LED1, 11 = WDT, * 10 = Either Edge Triggered Intr.4 * Bit 4-6 (Reserved) * Bit 7, Output Type: 0 = Push Pull Bit, 1 = Open Drain */ t = inb(sch311x_wdt_data.runtime_reg + GP60); outb((t & ~0x0d) | 0x0c, sch311x_wdt_data.runtime_reg + GP60); spin_unlock(&sch311x_wdt_data.io_lock); } static void sch311x_wdt_stop(void) { unsigned char t; spin_lock(&sch311x_wdt_data.io_lock); /* stop the watchdog */ t = inb(sch311x_wdt_data.runtime_reg + GP60); outb((t & ~0x0d) | 0x01, sch311x_wdt_data.runtime_reg + GP60); /* disable timeout by setting it to 0 */ sch311x_wdt_set_timeout(0); spin_unlock(&sch311x_wdt_data.io_lock); } static void sch311x_wdt_keepalive(void) { spin_lock(&sch311x_wdt_data.io_lock); sch311x_wdt_set_timeout(timeout); spin_unlock(&sch311x_wdt_data.io_lock); } static int sch311x_wdt_set_heartbeat(int t) { if (t < 1 || t > (255*60)) return -EINVAL; /* When new timeout is bigger then 255 seconds, * we will round up to minutes (with a max of 255) */ if (t > 255) t = (((t - 1) / 60) + 1) * 60; timeout = t; return 0; } static void sch311x_wdt_get_status(int *status) { unsigned char new_status; *status = 0; spin_lock(&sch311x_wdt_data.io_lock); /* -- Watchdog timer control -- * Bit 0 Status Bit: 0 = Timer counting, 1 = Timeout occurred * Bit 1 Reserved * Bit 2 Force Timeout: 1 = Forces WD timeout event (self-cleaning) * Bit 3 P20 Force Timeout enabled: * 0 = P20 activity does not generate the WD timeout event * 1 = P20 Allows rising edge of P20, from the keyboard * controller, to force the WD timeout event. * Bit 4-7 Reserved */ new_status = inb(sch311x_wdt_data.runtime_reg + WDT_CTRL); if (new_status & 0x01) *status |= WDIOF_CARDRESET; spin_unlock(&sch311x_wdt_data.io_lock); } /* * /dev/watchdog handling */ static ssize_t sch311x_wdt_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos) { if (count) { if (!nowayout) { size_t i; sch311x_wdt_expect_close = 0; for (i = 0; i != count; i++) { char c; if (get_user(c, buf + i)) return -EFAULT; if (c == 'V') sch311x_wdt_expect_close = 42; } } sch311x_wdt_keepalive(); } return count; } static long sch311x_wdt_ioctl(struct file *file, unsigned int cmd, unsigned long arg) { int status; int new_timeout; void __user *argp = (void __user *)arg; int __user *p = argp; static const struct watchdog_info ident = { .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE, .firmware_version = 1, .identity = DRV_NAME, }; switch (cmd) { case WDIOC_GETSUPPORT: if (copy_to_user(argp, &ident, sizeof(ident))) return -EFAULT; break; case WDIOC_GETSTATUS: { sch311x_wdt_get_status(&status); return put_user(status, p); } case WDIOC_GETBOOTSTATUS: return put_user(sch311x_wdt_data.boot_status, p); case WDIOC_SETOPTIONS: { int options, retval = -EINVAL; if (get_user(options, p)) return -EFAULT; if (options & WDIOS_DISABLECARD) { sch311x_wdt_stop(); retval = 0; } if (options & WDIOS_ENABLECARD) { sch311x_wdt_start(); retval = 0; } return retval; } case WDIOC_KEEPALIVE: sch311x_wdt_keepalive(); break; case WDIOC_SETTIMEOUT: if (get_user(new_timeout, p)) return -EFAULT; if (sch311x_wdt_set_heartbeat(new_timeout)) return -EINVAL; sch311x_wdt_keepalive(); fallthrough; case WDIOC_GETTIMEOUT: return put_user(timeout, p); default: return -ENOTTY; } return 0; } static int sch311x_wdt_open(struct inode *inode, struct file *file) { if (test_and_set_bit(0, &sch311x_wdt_is_open)) return -EBUSY; /* * Activate */ sch311x_wdt_start(); return stream_open(inode, file); } static int sch311x_wdt_close(struct inode *inode, struct file *file) { if (sch311x_wdt_expect_close == 42) { sch311x_wdt_stop(); } else { pr_crit("Unexpected close, not stopping watchdog!\n"); sch311x_wdt_keepalive(); } clear_bit(0, &sch311x_wdt_is_open); sch311x_wdt_expect_close = 0; return 0; } /* * Kernel Interfaces */ static const struct file_operations sch311x_wdt_fops = { .owner = THIS_MODULE, .write = sch311x_wdt_write, .unlocked_ioctl = sch311x_wdt_ioctl, .compat_ioctl = compat_ptr_ioctl, .open = sch311x_wdt_open, .release = sch311x_wdt_close, }; static struct miscdevice sch311x_wdt_miscdev = { .minor = WATCHDOG_MINOR, .name = "watchdog", .fops = &sch311x_wdt_fops, }; /* * Init & exit routines */ static int sch311x_wdt_probe(struct platform_device *pdev) { struct device *dev = &pdev->dev; int err; spin_lock_init(&sch311x_wdt_data.io_lock); if (!request_region(sch311x_wdt_data.runtime_reg + GP60, 1, DRV_NAME)) { dev_err(dev, "Failed to request region 0x%04x-0x%04x.\n", sch311x_wdt_data.runtime_reg + GP60, sch311x_wdt_data.runtime_reg + GP60); err = -EBUSY; goto exit; } if (!request_region(sch311x_wdt_data.runtime_reg + WDT_TIME_OUT, 4, DRV_NAME)) { dev_err(dev, "Failed to request region 0x%04x-0x%04x.\n", sch311x_wdt_data.runtime_reg + WDT_TIME_OUT, sch311x_wdt_data.runtime_reg + WDT_CTRL); err = -EBUSY; goto exit_release_region; } /* Make sure that the watchdog is not running */ sch311x_wdt_stop(); /* Disable keyboard and mouse interaction and interrupt */ /* -- Watchdog timer configuration -- * Bit 0 Reserved * Bit 1 Keyboard enable: 0* = No Reset, 1 = Reset WDT upon KBD Intr. * Bit 2 Mouse enable: 0* = No Reset, 1 = Reset WDT upon Mouse Intr * Bit 3 Reserved * Bit 4-7 WDT Interrupt Mapping: (0000* = Disabled, * 0001=IRQ1, 0010=(Invalid), 0011=IRQ3 to 1111=IRQ15) */ outb(0, sch311x_wdt_data.runtime_reg + WDT_CFG); /* Check that the heartbeat value is within it's range ; * if not reset to the default */ if (sch311x_wdt_set_heartbeat(timeout)) { sch311x_wdt_set_heartbeat(WATCHDOG_TIMEOUT); dev_info(dev, "timeout value must be 1<=x<=15300, using %d\n", timeout); } /* Get status at boot */ sch311x_wdt_get_status(&sch311x_wdt_data.boot_status); sch311x_wdt_miscdev.parent = dev; err = misc_register(&sch311x_wdt_miscdev); if (err != 0) { dev_err(dev, "cannot register miscdev on minor=%d (err=%d)\n", WATCHDOG_MINOR, err); goto exit_release_region2; } dev_info(dev, "SMSC SCH311x WDT initialized. timeout=%d sec (nowayout=%d)\n", timeout, nowayout); return 0; exit_release_region2: release_region(sch311x_wdt_data.runtime_reg + WDT_TIME_OUT, 4); exit_release_region: release_region(sch311x_wdt_data.runtime_reg + GP60, 1); sch311x_wdt_data.runtime_reg = 0; exit: return err; } static void sch311x_wdt_remove(struct platform_device *pdev) { /* Stop the timer before we leave */ if (!nowayout) sch311x_wdt_stop(); /* Deregister */ misc_deregister(&sch311x_wdt_miscdev); release_region(sch311x_wdt_data.runtime_reg + WDT_TIME_OUT, 4); release_region(sch311x_wdt_data.runtime_reg + GP60, 1); sch311x_wdt_data.runtime_reg = 0; } static void sch311x_wdt_shutdown(struct platform_device *dev) { /* Turn the WDT off if we have a soft shutdown */ sch311x_wdt_stop(); } static struct platform_driver sch311x_wdt_driver = { .probe = sch311x_wdt_probe, .remove_new = sch311x_wdt_remove, .shutdown = sch311x_wdt_shutdown, .driver = { .name = DRV_NAME, }, }; static int __init sch311x_detect(int sio_config_port, unsigned short *addr) { int err = 0, reg; unsigned short base_addr; unsigned char dev_id; sch311x_sio_enter(sio_config_port); /* Check device ID. We currently know about: * SCH3112 (0x7c), SCH3114 (0x7d), and SCH3116 (0x7f). */ reg = force_id ? force_id : sch311x_sio_inb(sio_config_port, 0x20); if (!(reg == 0x7c || reg == 0x7d || reg == 0x7f)) { err = -ENODEV; goto exit; } dev_id = reg == 0x7c ? 2 : reg == 0x7d ? 4 : 6; /* Select logical device A (runtime registers) */ sch311x_sio_outb(sio_config_port, 0x07, 0x0a); /* Check if Logical Device Register is currently active */ if ((sch311x_sio_inb(sio_config_port, 0x30) & 0x01) == 0) pr_info("Seems that LDN 0x0a is not active...\n"); /* Get the base address of the runtime registers */ base_addr = (sch311x_sio_inb(sio_config_port, 0x60) << 8) | sch311x_sio_inb(sio_config_port, 0x61); if (!base_addr) { pr_err("Base address not set\n"); err = -ENODEV; goto exit; } *addr = base_addr; pr_info("Found an SMSC SCH311%d chip at 0x%04x\n", dev_id, base_addr); exit: sch311x_sio_exit(sio_config_port); return err; } static int __init sch311x_wdt_init(void) { int err, i, found = 0; unsigned short addr = 0; for (i = 0; !found && sch311x_ioports[i]; i++) if (sch311x_detect(sch311x_ioports[i], &addr) == 0) found++; if (!found) return -ENODEV; sch311x_wdt_data.runtime_reg = addr; err = platform_driver_register(&sch311x_wdt_driver); if (err) return err; sch311x_wdt_pdev = platform_device_register_simple(DRV_NAME, addr, NULL, 0); if (IS_ERR(sch311x_wdt_pdev)) { err = PTR_ERR(sch311x_wdt_pdev); goto unreg_platform_driver; } return 0; unreg_platform_driver: platform_driver_unregister(&sch311x_wdt_driver); return err; } static void __exit sch311x_wdt_exit(void) { platform_device_unregister(sch311x_wdt_pdev); platform_driver_unregister(&sch311x_wdt_driver); } module_init(sch311x_wdt_init); module_exit(sch311x_wdt_exit); MODULE_AUTHOR("Wim Van Sebroeck "); MODULE_DESCRIPTION("SMSC SCH311x WatchDog Timer Driver"); MODULE_LICENSE("GPL");