diff options
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/char/watchdog/Kconfig | 20 | ||||
| -rw-r--r-- | drivers/char/watchdog/Makefile | 1 | ||||
| -rw-r--r-- | drivers/char/watchdog/smsc37b787_wdt.c | 614 |
3 files changed, 635 insertions, 0 deletions
diff --git a/drivers/char/watchdog/Kconfig b/drivers/char/watchdog/Kconfig index 89e46d6..8d2ebc7 100644 --- a/drivers/char/watchdog/Kconfig +++ b/drivers/char/watchdog/Kconfig @@ -395,6 +395,26 @@ config CPU5_WDT To compile this driver as a module, choose M here: the module will be called cpu5wdt. +config SMSC37B787_WDT + tristate "Winbond SMsC37B787 Watchdog Timer" + depends on WATCHDOG && X86 + ---help--- + This is the driver for the hardware watchdog component on the + Winbond SMsC37B787 chipset as used on the NetRunner Mainboard + from Vision Systems and maybe others. + + This watchdog simply watches your kernel to make sure it doesn't + freeze, and if it does, it reboots your computer after a certain + amount of time. + + Usually a userspace daemon will notify the kernel WDT driver that + userspace is still alive, at regular intervals. + + To compile this driver as a module, choose M here: the + module will be called smsc37b787_wdt. + + Most people will say N. + config W83627HF_WDT tristate "W83627HF Watchdog Timer" depends on WATCHDOG && X86 diff --git a/drivers/char/watchdog/Makefile b/drivers/char/watchdog/Makefile index 7f70aba..630526f 100644 --- a/drivers/char/watchdog/Makefile +++ b/drivers/char/watchdog/Makefile @@ -53,6 +53,7 @@ obj-$(CONFIG_SCx200_WDT) += scx200_wdt.o obj-$(CONFIG_60XX_WDT) += sbc60xxwdt.o obj-$(CONFIG_SBC8360_WDT) += sbc8360.o obj-$(CONFIG_CPU5_WDT) += cpu5wdt.o +obj-$(CONFIG_SMSC37B787_WDT) += smsc37b787_wdt.o obj-$(CONFIG_W83627HF_WDT) += w83627hf_wdt.o obj-$(CONFIG_W83877F_WDT) += w83877f_wdt.o obj-$(CONFIG_W83977F_WDT) += w83977f_wdt.o diff --git a/drivers/char/watchdog/smsc37b787_wdt.c b/drivers/char/watchdog/smsc37b787_wdt.c new file mode 100644 index 0000000..47141c0 --- /dev/null +++ b/drivers/char/watchdog/smsc37b787_wdt.c @@ -0,0 +1,614 @@ +/* + * SMsC 37B787 Watchdog Timer driver for Linux 2.6.x.x + * + * Based on acquirewdt.c by Alan Cox <alan@redhat.com> + * and some other existing drivers + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + * + * The authors do NOT admit liability nor provide warranty for + * any of this software. This material is provided "AS-IS" in + * the hope that it may be useful for others. + * + * (C) Copyright 2003-2006 Sven Anders <anders@anduras.de> + * + * History: + * 2003 - Created version 1.0 for Linux 2.4.x. + * 2006 - Ported to Linux 2.6, added nowayout and MAGICCLOSE + * features. Released version 1.1 + * + * Theory of operation: + * + * A Watchdog Timer (WDT) is a hardware circuit that can + * reset the computer system in case of a software fault. + * You probably knew that already. + * + * Usually a userspace daemon will notify the kernel WDT driver + * via the /dev/watchdog special device file that userspace is + * still alive, at regular intervals. When such a notification + * occurs, the driver will usually tell the hardware watchdog + * that everything is in order, and that the watchdog should wait + * for yet another little while to reset the system. + * If userspace fails (RAM error, kernel bug, whatever), the + * notifications cease to occur, and the hardware watchdog will + * reset the system (causing a reboot) after the timeout occurs. + * + * Create device with: + * mknod /dev/watchdog c 10 130 + * + * For an example userspace keep-alive daemon, see: + * Documentation/watchdog/watchdog.txt + */ + +#include <linux/module.h> +#include <linux/moduleparam.h> +#include <linux/types.h> +#include <linux/miscdevice.h> +#include <linux/watchdog.h> +#include <linux/delay.h> +#include <linux/fs.h> +#include <linux/ioport.h> +#include <linux/notifier.h> +#include <linux/reboot.h> +#include <linux/init.h> + +#include <asm/io.h> +#include <asm/uaccess.h> +#include <asm/system.h> + +/* enable support for minutes as units? */ +/* (does not always work correctly, so disabled by default!) */ +#define SMSC_SUPPORT_MINUTES +#undef SMSC_SUPPORT_MINUTES + +#define MAX_TIMEOUT 255 + +#define UNIT_SECOND 0 +#define UNIT_MINUTE 1 + +#define MODNAME "smsc37b787_wdt: " +#define VERSION "1.1" + +#define WATCHDOG_MINOR 130 + +#define IOPORT 0x3F0 +#define IOPORT_SIZE 2 +#define IODEV_NO 8 + +static int unit = UNIT_SECOND; /* timer's unit */ +static int timeout = 60; /* timeout value: default is 60 "units" */ +static int timer_enabled = 0; /* is the timer enabled? */ + +static char expect_close; /* is the close expected? */ + +static int nowayout = WATCHDOG_NOWAYOUT; + +/* -- Low level function ----------------------------------------*/ + +/* unlock the IO chip */ + +static inline void open_io_config(void) +{ + outb(0x55, IOPORT); + mdelay(1); + outb(0x55, IOPORT); +} + +/* lock the IO chip */ +static inline void close_io_config(void) +{ + outb(0xAA, IOPORT); +} + +/* select the IO device */ +static inline void select_io_device(unsigned char devno) +{ + outb(0x07, IOPORT); + outb(devno, IOPORT+1); +} + +/* write to the control register */ +static inline void write_io_cr(unsigned char reg, unsigned char data) +{ + outb(reg, IOPORT); + outb(data, IOPORT+1); +} + +/* read from the control register */ +static inline char read_io_cr(unsigned char reg) +{ + outb(reg, IOPORT); + return inb(IOPORT+1); +} + +/* -- Medium level functions ------------------------------------*/ + +static inline void gpio_bit12(unsigned char reg) +{ + // -- General Purpose I/O Bit 1.2 -- + // Bit 0, In/Out: 0 = Output, 1 = Input + // Bit 1, Polarity: 0 = No Invert, 1 = Invert + // Bit 2, Group Enable Intr.: 0 = Disable, 1 = Enable + // Bit 3/4, Function select: 00 = GPI/O, 01 = WDT, 10 = P17, + // 11 = Either Edge Triggered Intr. 2 + // Bit 5/6 (Reserved) + // Bit 7, Output Type: 0 = Push Pull Bit, 1 = Open Drain + write_io_cr(0xE2, reg); +} + +static inline void gpio_bit13(unsigned char reg) +{ + // -- General Purpose I/O Bit 1.3 -- + // Bit 0, In/Out: 0 = Output, 1 = Input + // Bit 1, Polarity: 0 = No Invert, 1 = Invert + // Bit 2, Group Enable Intr.: 0 = Disable, 1 = Enable + // Bit 3, Function select: 0 = GPI/O, 1 = LED + // Bit 4-6 (Reserved) + // Bit 7, Output Type: 0 = Push Pull Bit, 1 = Open Drain + write_io_cr(0xE3, reg); +} + +static inline void wdt_timer_units(unsigned char new_units) +{ + // -- Watchdog timer units -- + // Bit 0-6 (Reserved) + // Bit 7, WDT Time-out Value Units Select + // (0 = Minutes, 1 = Seconds) + write_io_cr(0xF1, new_units); +} + +static inline void wdt_timeout_value(unsigned char new_timeout) +{ + // -- Watchdog Timer Time-out Value -- + // Bit 0-7 Binary coded units (0=Disabled, 1..255) + write_io_cr(0xF2, new_timeout); +} + +static inline void wdt_timer_conf(unsigned char conf) +{ + // -- Watchdog timer configuration -- + // Bit 0 Joystick enable: 0* = No Reset, 1 = Reset WDT upon Gameport I/O + // 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 Reset the timer + // (Wrong in SMsC documentation? Given as: PowerLED Timout Enabled) + // Bit 4-7 WDT Interrupt Mapping: (0000* = Disabled, + // 0001=IRQ1, 0010=(Invalid), 0011=IRQ3 to 1111=IRQ15) + write_io_cr(0xF3, conf); +} + +static inline void wdt_timer_ctrl(unsigned char reg) +{ + // -- Watchdog timer control -- + // Bit 0 Status Bit: 0 = Timer counting, 1 = Timeout occured + // Bit 1 Power LED Toggle: 0 = Disable Toggle, 1 = Toggle at 1 Hz + // 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 (Reserved) + // -- Soft power management -- + // Bit 5 Stop Counter: 1 = Stop software power down counter + // set via register 0xB8, (self-cleaning) + // (Upon read: 0 = Counter running, 1 = Counter stopped) + // Bit 6 Restart Counter: 1 = Restart software power down counter + // set via register 0xB8, (self-cleaning) + // Bit 7 SPOFF: 1 = Force software power down (self-cleaning) + + write_io_cr(0xF4, reg); +} + +/* -- Higher level functions ------------------------------------*/ + +/* initialize watchdog */ + +static void wb_smsc_wdt_initialize(void) +{ + unsigned char old; + + open_io_config(); + select_io_device(IODEV_NO); + + // enable the watchdog + gpio_bit13(0x08); // Select pin 80 = LED not GPIO + gpio_bit12(0x0A); // Set pin 79 = WDT not GPIO/Output/Polarity=Invert + + // disable the timeout + wdt_timeout_value(0); + + // reset control register + wdt_timer_ctrl(0x00); + + // reset configuration register + wdt_timer_conf(0x00); + + // read old (timer units) register + old = read_io_cr(0xF1) & 0x7F; + if (unit == UNIT_SECOND) old |= 0x80; // set to seconds + + // set the watchdog timer units + wdt_timer_units(old); + + close_io_config(); +} + +/* shutdown the watchdog */ + +static void wb_smsc_wdt_shutdown(void) +{ + open_io_config(); + select_io_device(IODEV_NO); + + // disable the watchdog + gpio_bit13(0x09); + gpio_bit12(0x09); + + // reset watchdog config register + wdt_timer_conf(0x00); + + // reset watchdog control register + wdt_timer_ctrl(0x00); + + // disable timeout + wdt_timeout_value(0x00); + + close_io_config(); +} + +/* set timeout => enable watchdog */ + +static void wb_smsc_wdt_set_timeout(unsigned char new_timeout) +{ + open_io_config(); + select_io_device(IODEV_NO); + + // set Power LED to blink, if we enable the timeout + wdt_timer_ctrl((new_timeout == 0) ? 0x00 : 0x02); + + // set timeout value + wdt_timeout_value(new_timeout); + + close_io_config(); +} + +/* get timeout */ + +static unsigned char wb_smsc_wdt_get_timeout(void) +{ + unsigned char set_timeout; + + open_io_config(); + select_io_device(IODEV_NO); + set_timeout = read_io_cr(0xF2); + close_io_config(); + + return set_timeout; +} + +/* disable watchdog */ + +static void wb_smsc_wdt_disable(void) +{ + // set the timeout to 0 to disable the watchdog + wb_smsc_wdt_set_timeout(0); +} + +/* enable watchdog by setting the current timeout */ + +static void wb_smsc_wdt_enable(void) +{ + // set the current timeout... + wb_smsc_wdt_set_timeout(timeout); +} + +/* reset the timer */ + +static void wb_smsc_wdt_reset_timer(void) +{ + open_io_config(); + select_io_device(IODEV_NO); + + // reset the timer + wdt_timeout_value(timeout); + wdt_timer_conf(0x08); + + close_io_config(); +} + +/* return, if the watchdog is enabled (timeout is set...) */ + +static int wb_smsc_wdt_status(void) +{ + return (wb_smsc_wdt_get_timeout() == 0) ? 0 : WDIOF_KEEPALIVEPING; +} + + +/* -- File operations -------------------------------------------*/ + +/* open => enable watchdog and set initial timeout */ + +static int wb_smsc_wdt_open(struct inode *inode, struct file *file) +{ + /* /dev/watchdog can only be opened once */ + + if (timer_enabled) + return -EBUSY; + + if (nowayout) + __module_get(THIS_MODULE); + + /* Reload and activate timer */ + timer_enabled = 1; + wb_smsc_wdt_enable(); + + printk(KERN_INFO MODNAME "Watchdog enabled. Timeout set to %d %s.\n", timeout, (unit == UNIT_SECOND) ? "second(s)" : "minute(s)"); + + return nonseekable_open(inode, file); +} + +/* close => shut off the timer */ + +static int wb_smsc_wdt_release(struct inode *inode, struct file *file) +{ + /* Shut off the timer. */ + + if (expect_close == 42) { + wb_smsc_wdt_disable(); + printk(KERN_INFO MODNAME "Watchdog disabled, sleeping again...\n"); + } else { + printk(KERN_CRIT MODNAME "Unexpected close, not stopping watchdog!\n"); + wb_smsc_wdt_reset_timer(); + } + + timer_enabled = 0; + expect_close = 0; + return 0; +} + +/* write => update the timer to keep the machine alive */ + +static ssize_t wb_smsc_wdt_write(struct file *file, const char __user *data, + size_t len, loff_t *ppos) +{ + /* See if we got the magic character 'V' and reload the timer */ + if (len) { + if (!nowayout) { + size_t i; + + /* reset expect flag */ + expect_close = 0; + + /* scan to see whether or not we got the magic character */ + for (i = 0; i != len; i++) { + char c; + if (get_user(c, data+i)) + return -EFAULT; + if (c == 'V') + expect_close = 42; + } + } + + /* someone wrote to us, we should reload the timer */ + wb_smsc_wdt_reset_timer(); + } + return len; +} + +/* ioctl => control interface */ + +static int wb_smsc_wdt_ioctl(struct inode *inode, struct file *file, + unsigned int cmd, unsigned long arg) +{ + int new_timeout; + + union { + struct watchdog_info __user *ident; + int __user *i; + } uarg; + + static struct watchdog_info ident = { + .options = WDIOF_KEEPALIVEPING | + WDIOF_SETTIMEOUT | + WDIOF_MAGICCLOSE, + .firmware_version = 0, + .identity = "SMsC 37B787 Watchdog" + }; + + uarg.i = (int __user *)arg; + + switch (cmd) { + default: + return -ENOTTY; + + case WDIOC_GETSUPPORT: + return copy_to_user(uarg.ident, &ident, sizeof(ident)); + + case WDIOC_GETSTATUS: + return put_user(wb_smsc_wdt_status(), uarg.i); + + case WDIOC_GETBOOTSTATUS: + return put_user(0, uarg.i); + + case WDIOC_KEEPALIVE: + wb_smsc_wdt_reset_timer(); + return 0; + + case WDIOC_SETTIMEOUT: + if (get_user(new_timeout, uarg.i)) + return -EFAULT; + + // the API states this is given in secs + if (unit == UNIT_MINUTE) + new_timeout /= 60; + + if (new_timeout < 0 || new_timeout > MAX_TIMEOUT) + return -EINVAL; + + timeout = new_timeout; + wb_smsc_wdt_set_timeout(timeout); + + // fall through and return the new timeout... + + case WDIOC_GETTIMEOUT: + + new_timeout = timeout; + + if (unit == UNIT_MINUTE) + new_timeout *= 60; + + return put_user(new_timeout, uarg.i); + + case WDIOC_SETOPTIONS: + { + int options, retval = -EINVAL; + + if (get_user(options, uarg.i)) + return -EFAULT; + + if (options & WDIOS_DISABLECARD) { + wb_smsc_wdt_disable(); + retval = 0; + } + + if (options & WDIOS_ENABLECARD) { + wb_smsc_wdt_enable(); + retval = 0; + } + + return retval; + } + } +} + +/* -- Notifier funtions -----------------------------------------*/ + +static int wb_smsc_wdt_notify_sys(struct notifier_block *this, unsigned long code, void *unused) +{ + if (code == SYS_DOWN || code == SYS_HALT) + { + // set timeout to 0, to avoid possible race-condition + timeout = 0; + wb_smsc_wdt_disable(); + } + return NOTIFY_DONE; +} + +/* -- Module's structures ---------------------------------------*/ + +static struct file_operations wb_smsc_wdt_fops = +{ + .owner = THIS_MODULE, + .llseek = no_llseek, + .write = wb_smsc_wdt_write, + .ioctl = wb_smsc_wdt_ioctl, + .open = wb_smsc_wdt_open, + .release = wb_smsc_wdt_release +}; + +static struct notifier_block wb_smsc_wdt_notifier = +{ + .notifier_call = wb_smsc_wdt_notify_sys +}; + +static struct miscdevice wb_smsc_wdt_miscdev = +{ + .minor = WATCHDOG_MINOR, + .name = "watchdog", + .fops = &wb_smsc_wdt_fops, +}; + +/* -- Module init functions -------------------------------------*/ + +/* module's "constructor" */ + +static int __init wb_smsc_wdt_init(void) +{ + int ret; + + printk("SMsC 37B787 watchdog component driver " VERSION " initialising...\n"); + + if (!request_region(IOPORT, IOPORT_SIZE, "SMsC 37B787 watchdog")) { + printk(KERN_ERR MODNAME "Unable to register IO port %#x\n", IOPORT); + ret = -EBUSY; + goto out_pnp; + } + + ret = register_reboot_notifier(&wb_smsc_wdt_notifier); + if (ret) { + printk(KERN_ERR MODNAME "Unable to register reboot notifier err = %d\n", ret); + goto out_io; + } + + ret = misc_register(&wb_smsc_wdt_miscdev); + if (ret) { + printk(KERN_ERR MODNAME "Unable to register miscdev on minor %d\n", WATCHDOG_MINOR); + goto out_rbt; + } + + // init the watchdog timer + wb_smsc_wdt_initialize(); + + // set new maximum, if it's too big + if (timeout > MAX_TIMEOUT) + timeout = MAX_TIMEOUT; + + // output info + printk(KERN_INFO MODNAME "Timeout set to %d %s.\n", timeout, (unit == UNIT_SECOND) ? "second(s)" : "minute(s)"); + printk(KERN_INFO MODNAME "Watchdog initialized and sleeping (nowayout=%d)...\n", nowayout); + + // ret = 0 + +out_clean: + return ret; + +out_rbt: + unregister_reboot_notifier(&wb_smsc_wdt_notifier); + +out_io: + release_region(IOPORT, IOPORT_SIZE); + +out_pnp: + goto out_clean; +} + +/* module's "destructor" */ + +static void __exit wb_smsc_wdt_exit(void) +{ + /* Stop the timer before we leave */ + if (!nowayout) + { + wb_smsc_wdt_shutdown(); + printk(KERN_INFO MODNAME "Watchdog disabled.\n"); + } + + misc_deregister(&wb_smsc_wdt_miscdev); + unregister_reboot_notifier(&wb_smsc_wdt_notifier); + release_region(IOPORT, IOPORT_SIZE); + + printk("SMsC 37B787 watchdog component driver removed.\n"); +} + +module_init(wb_smsc_wdt_init); +module_exit(wb_smsc_wdt_exit); + +MODULE_AUTHOR("Sven Anders <anders@anduras.de>"); +MODULE_DESCRIPTION("Driver for SMsC 37B787 watchdog component (Version " VERSION ")"); +MODULE_LICENSE("GPL"); + +MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); + +#ifdef SMSC_SUPPORT_MINUTES +module_param(unit, int, 0); +MODULE_PARM_DESC(unit, "set unit to use, 0=seconds or 1=minutes, default is 0"); +#endif + +module_param(timeout, int, 60); +MODULE_PARM_DESC(timeout, "range is 1-255 units, default is 60"); + +module_param(nowayout, int, 0); +MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=CONFIG_WATCHDOG_NOWAYOUT)"); |