diff options
Diffstat (limited to 'drivers/watchdog/pc87413_wdt.c')
| -rw-r--r-- | drivers/watchdog/pc87413_wdt.c | 598 |
1 files changed, 598 insertions, 0 deletions
diff --git a/drivers/watchdog/pc87413_wdt.c b/drivers/watchdog/pc87413_wdt.c new file mode 100644 index 00000000..5afb89b4 --- /dev/null +++ b/drivers/watchdog/pc87413_wdt.c @@ -0,0 +1,598 @@ +/* + * NS pc87413-wdt Watchdog Timer driver for Linux 2.6.x.x + * + * This code is based on wdt.c with original copyright. + * + * (C) Copyright 2006 Sven Anders, <anders@anduras.de> + * and Marcus Junker, <junker@anduras.de> + * + * 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. + * + * Neither Sven Anders, Marcus Junker nor ANDURAS AG + * admit liability nor provide warranty for any of this software. + * This material is provided "AS-IS" and at no charge. + * + * Release 1.1 + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/module.h> +#include <linux/types.h> +#include <linux/miscdevice.h> +#include <linux/watchdog.h> +#include <linux/ioport.h> +#include <linux/delay.h> +#include <linux/notifier.h> +#include <linux/fs.h> +#include <linux/reboot.h> +#include <linux/init.h> +#include <linux/spinlock.h> +#include <linux/moduleparam.h> +#include <linux/io.h> +#include <linux/uaccess.h> + + +/* #define DEBUG 1 */ + +#define DEFAULT_TIMEOUT 1 /* 1 minute */ +#define MAX_TIMEOUT 255 + +#define VERSION "1.1" +#define MODNAME "pc87413 WDT" +#define DPFX MODNAME " - DEBUG: " + +#define WDT_INDEX_IO_PORT (io+0) /* I/O port base (index register) */ +#define WDT_DATA_IO_PORT (WDT_INDEX_IO_PORT+1) +#define SWC_LDN 0x04 +#define SIOCFG2 0x22 /* Serial IO register */ +#define WDCTL 0x10 /* Watchdog-Timer-Control-Register */ +#define WDTO 0x11 /* Watchdog timeout register */ +#define WDCFG 0x12 /* Watchdog config register */ + +#define IO_DEFAULT 0x2E /* Address used on Portwell Boards */ + +static int io = IO_DEFAULT; +static int swc_base_addr = -1; + +static int timeout = DEFAULT_TIMEOUT; /* timeout value */ +static unsigned long timer_enabled; /* is the timer enabled? */ + +static char expect_close; /* is the close expected? */ + +static DEFINE_SPINLOCK(io_lock); /* to guard us from io races */ + +static bool nowayout = WATCHDOG_NOWAYOUT; + +/* -- Low level function ----------------------------------------*/ + +/* Select pins for Watchdog output */ + +static inline void pc87413_select_wdt_out(void) +{ + unsigned int cr_data = 0; + + /* Step 1: Select multiple pin,pin55,as WDT output */ + + outb_p(SIOCFG2, WDT_INDEX_IO_PORT); + + cr_data = inb(WDT_DATA_IO_PORT); + + cr_data |= 0x80; /* Set Bit7 to 1*/ + outb_p(SIOCFG2, WDT_INDEX_IO_PORT); + + outb_p(cr_data, WDT_DATA_IO_PORT); + +#ifdef DEBUG + pr_info(DPFX + "Select multiple pin,pin55,as WDT output: Bit7 to 1: %d\n", + cr_data); +#endif +} + +/* Enable SWC functions */ + +static inline void pc87413_enable_swc(void) +{ + unsigned int cr_data = 0; + + /* Step 2: Enable SWC functions */ + + outb_p(0x07, WDT_INDEX_IO_PORT); /* Point SWC_LDN (LDN=4) */ + outb_p(SWC_LDN, WDT_DATA_IO_PORT); + + outb_p(0x30, WDT_INDEX_IO_PORT); /* Read Index 0x30 First */ + cr_data = inb(WDT_DATA_IO_PORT); + cr_data |= 0x01; /* Set Bit0 to 1 */ + outb_p(0x30, WDT_INDEX_IO_PORT); + outb_p(cr_data, WDT_DATA_IO_PORT); /* Index0x30_bit0P1 */ + +#ifdef DEBUG + pr_info(DPFX "pc87413 - Enable SWC functions\n"); +#endif +} + +/* Read SWC I/O base address */ + +static void pc87413_get_swc_base_addr(void) +{ + unsigned char addr_l, addr_h = 0; + + /* Step 3: Read SWC I/O Base Address */ + + outb_p(0x60, WDT_INDEX_IO_PORT); /* Read Index 0x60 */ + addr_h = inb(WDT_DATA_IO_PORT); + + outb_p(0x61, WDT_INDEX_IO_PORT); /* Read Index 0x61 */ + + addr_l = inb(WDT_DATA_IO_PORT); + + swc_base_addr = (addr_h << 8) + addr_l; +#ifdef DEBUG + pr_info(DPFX + "Read SWC I/O Base Address: low %d, high %d, res %d\n", + addr_l, addr_h, swc_base_addr); +#endif +} + +/* Select Bank 3 of SWC */ + +static inline void pc87413_swc_bank3(void) +{ + /* Step 4: Select Bank3 of SWC */ + outb_p(inb(swc_base_addr + 0x0f) | 0x03, swc_base_addr + 0x0f); +#ifdef DEBUG + pr_info(DPFX "Select Bank3 of SWC\n"); +#endif +} + +/* Set watchdog timeout to x minutes */ + +static inline void pc87413_programm_wdto(char pc87413_time) +{ + /* Step 5: Programm WDTO, Twd. */ + outb_p(pc87413_time, swc_base_addr + WDTO); +#ifdef DEBUG + pr_info(DPFX "Set WDTO to %d minutes\n", pc87413_time); +#endif +} + +/* Enable WDEN */ + +static inline void pc87413_enable_wden(void) +{ + /* Step 6: Enable WDEN */ + outb_p(inb(swc_base_addr + WDCTL) | 0x01, swc_base_addr + WDCTL); +#ifdef DEBUG + pr_info(DPFX "Enable WDEN\n"); +#endif +} + +/* Enable SW_WD_TREN */ +static inline void pc87413_enable_sw_wd_tren(void) +{ + /* Enable SW_WD_TREN */ + outb_p(inb(swc_base_addr + WDCFG) | 0x80, swc_base_addr + WDCFG); +#ifdef DEBUG + pr_info(DPFX "Enable SW_WD_TREN\n"); +#endif +} + +/* Disable SW_WD_TREN */ + +static inline void pc87413_disable_sw_wd_tren(void) +{ + /* Disable SW_WD_TREN */ + outb_p(inb(swc_base_addr + WDCFG) & 0x7f, swc_base_addr + WDCFG); +#ifdef DEBUG + pr_info(DPFX "pc87413 - Disable SW_WD_TREN\n"); +#endif +} + +/* Enable SW_WD_TRG */ + +static inline void pc87413_enable_sw_wd_trg(void) +{ + /* Enable SW_WD_TRG */ + outb_p(inb(swc_base_addr + WDCTL) | 0x80, swc_base_addr + WDCTL); +#ifdef DEBUG + pr_info(DPFX "pc87413 - Enable SW_WD_TRG\n"); +#endif +} + +/* Disable SW_WD_TRG */ + +static inline void pc87413_disable_sw_wd_trg(void) +{ + /* Disable SW_WD_TRG */ + outb_p(inb(swc_base_addr + WDCTL) & 0x7f, swc_base_addr + WDCTL); +#ifdef DEBUG + pr_info(DPFX "Disable SW_WD_TRG\n"); +#endif +} + +/* -- Higher level functions ------------------------------------*/ + +/* Enable the watchdog */ + +static void pc87413_enable(void) +{ + spin_lock(&io_lock); + + pc87413_swc_bank3(); + pc87413_programm_wdto(timeout); + pc87413_enable_wden(); + pc87413_enable_sw_wd_tren(); + pc87413_enable_sw_wd_trg(); + + spin_unlock(&io_lock); +} + +/* Disable the watchdog */ + +static void pc87413_disable(void) +{ + spin_lock(&io_lock); + + pc87413_swc_bank3(); + pc87413_disable_sw_wd_tren(); + pc87413_disable_sw_wd_trg(); + pc87413_programm_wdto(0); + + spin_unlock(&io_lock); +} + +/* Refresh the watchdog */ + +static void pc87413_refresh(void) +{ + spin_lock(&io_lock); + + pc87413_swc_bank3(); + pc87413_disable_sw_wd_tren(); + pc87413_disable_sw_wd_trg(); + pc87413_programm_wdto(timeout); + pc87413_enable_wden(); + pc87413_enable_sw_wd_tren(); + pc87413_enable_sw_wd_trg(); + + spin_unlock(&io_lock); +} + +/* -- File operations -------------------------------------------*/ + +/** + * pc87413_open: + * @inode: inode of device + * @file: file handle to device + * + */ + +static int pc87413_open(struct inode *inode, struct file *file) +{ + /* /dev/watchdog can only be opened once */ + + if (test_and_set_bit(0, &timer_enabled)) + return -EBUSY; + + if (nowayout) + __module_get(THIS_MODULE); + + /* Reload and activate timer */ + pc87413_refresh(); + + pr_info("Watchdog enabled. Timeout set to %d minute(s).\n", timeout); + + return nonseekable_open(inode, file); +} + +/** + * pc87413_release: + * @inode: inode to board + * @file: file handle to board + * + * The watchdog has a configurable API. There is a religious dispute + * between people who want their watchdog to be able to shut down and + * those who want to be sure if the watchdog manager dies the machine + * reboots. In the former case we disable the counters, in the latter + * case you have to open it again very soon. + */ + +static int pc87413_release(struct inode *inode, struct file *file) +{ + /* Shut off the timer. */ + + if (expect_close == 42) { + pc87413_disable(); + pr_info("Watchdog disabled, sleeping again...\n"); + } else { + pr_crit("Unexpected close, not stopping watchdog!\n"); + pc87413_refresh(); + } + clear_bit(0, &timer_enabled); + expect_close = 0; + return 0; +} + +/** + * pc87413_status: + * + * return, if the watchdog is enabled (timeout is set...) + */ + + +static int pc87413_status(void) +{ + return 0; /* currently not supported */ +} + +/** + * pc87413_write: + * @file: file handle to the watchdog + * @data: data buffer to write + * @len: length in bytes + * @ppos: pointer to the position to write. No seeks allowed + * + * A write to a watchdog device is defined as a keepalive signal. Any + * write of data will do, as we we don't define content meaning. + */ + +static ssize_t pc87413_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 */ + pc87413_refresh(); + } + return len; +} + +/** + * pc87413_ioctl: + * @file: file handle to the device + * @cmd: watchdog command + * @arg: argument pointer + * + * The watchdog API defines a common set of functions for all watchdogs + * according to their available features. We only actually usefully support + * querying capabilities and current status. + */ + +static long pc87413_ioctl(struct file *file, unsigned int cmd, + unsigned long arg) +{ + int new_timeout; + + union { + struct watchdog_info __user *ident; + int __user *i; + } uarg; + + static const struct watchdog_info ident = { + .options = WDIOF_KEEPALIVEPING | + WDIOF_SETTIMEOUT | + WDIOF_MAGICCLOSE, + .firmware_version = 1, + .identity = "PC87413(HF/F) watchdog", + }; + + uarg.i = (int __user *)arg; + + switch (cmd) { + case WDIOC_GETSUPPORT: + return copy_to_user(uarg.ident, &ident, + sizeof(ident)) ? -EFAULT : 0; + case WDIOC_GETSTATUS: + return put_user(pc87413_status(), uarg.i); + case WDIOC_GETBOOTSTATUS: + return put_user(0, uarg.i); + case WDIOC_SETOPTIONS: + { + int options, retval = -EINVAL; + if (get_user(options, uarg.i)) + return -EFAULT; + if (options & WDIOS_DISABLECARD) { + pc87413_disable(); + retval = 0; + } + if (options & WDIOS_ENABLECARD) { + pc87413_enable(); + retval = 0; + } + return retval; + } + case WDIOC_KEEPALIVE: + pc87413_refresh(); +#ifdef DEBUG + pr_info(DPFX "keepalive\n"); +#endif + return 0; + case WDIOC_SETTIMEOUT: + if (get_user(new_timeout, uarg.i)) + return -EFAULT; + /* the API states this is given in secs */ + new_timeout /= 60; + if (new_timeout < 0 || new_timeout > MAX_TIMEOUT) + return -EINVAL; + timeout = new_timeout; + pc87413_refresh(); + /* fall through and return the new timeout... */ + case WDIOC_GETTIMEOUT: + new_timeout = timeout * 60; + return put_user(new_timeout, uarg.i); + default: + return -ENOTTY; + } +} + +/* -- Notifier funtions -----------------------------------------*/ + +/** + * notify_sys: + * @this: our notifier block + * @code: the event being reported + * @unused: unused + * + * Our notifier is called on system shutdowns. We want to turn the card + * off at reboot otherwise the machine will reboot again during memory + * test or worse yet during the following fsck. This would suck, in fact + * trust me - if it happens it does suck. + */ + +static int pc87413_notify_sys(struct notifier_block *this, + unsigned long code, + void *unused) +{ + if (code == SYS_DOWN || code == SYS_HALT) + /* Turn the card off */ + pc87413_disable(); + return NOTIFY_DONE; +} + +/* -- Module's structures ---------------------------------------*/ + +static const struct file_operations pc87413_fops = { + .owner = THIS_MODULE, + .llseek = no_llseek, + .write = pc87413_write, + .unlocked_ioctl = pc87413_ioctl, + .open = pc87413_open, + .release = pc87413_release, +}; + +static struct notifier_block pc87413_notifier = { + .notifier_call = pc87413_notify_sys, +}; + +static struct miscdevice pc87413_miscdev = { + .minor = WATCHDOG_MINOR, + .name = "watchdog", + .fops = &pc87413_fops, +}; + +/* -- Module init functions -------------------------------------*/ + +/** + * pc87413_init: module's "constructor" + * + * Set up the WDT watchdog board. All we have to do is grab the + * resources we require and bitch if anyone beat us to them. + * The open() function will actually kick the board off. + */ + +static int __init pc87413_init(void) +{ + int ret; + + pr_info("Version " VERSION " at io 0x%X\n", + WDT_INDEX_IO_PORT); + + if (!request_muxed_region(io, 2, MODNAME)) + return -EBUSY; + + ret = register_reboot_notifier(&pc87413_notifier); + if (ret != 0) { + pr_err("cannot register reboot notifier (err=%d)\n", ret); + } + + ret = misc_register(&pc87413_miscdev); + if (ret != 0) { + pr_err("cannot register miscdev on minor=%d (err=%d)\n", + WATCHDOG_MINOR, ret); + goto reboot_unreg; + } + pr_info("initialized. timeout=%d min\n", timeout); + + pc87413_select_wdt_out(); + pc87413_enable_swc(); + pc87413_get_swc_base_addr(); + + if (!request_region(swc_base_addr, 0x20, MODNAME)) { + pr_err("cannot request SWC region at 0x%x\n", swc_base_addr); + ret = -EBUSY; + goto misc_unreg; + } + + pc87413_enable(); + + release_region(io, 2); + return 0; + +misc_unreg: + misc_deregister(&pc87413_miscdev); +reboot_unreg: + unregister_reboot_notifier(&pc87413_notifier); + release_region(io, 2); + return ret; +} + +/** + * pc87413_exit: module's "destructor" + * + * Unload the watchdog. You cannot do this with any file handles open. + * If your watchdog is set to continue ticking on close and you unload + * it, well it keeps ticking. We won't get the interrupt but the board + * will not touch PC memory so all is fine. You just have to load a new + * module in 60 seconds or reboot. + */ + +static void __exit pc87413_exit(void) +{ + /* Stop the timer before we leave */ + if (!nowayout) { + pc87413_disable(); + pr_info("Watchdog disabled\n"); + } + + misc_deregister(&pc87413_miscdev); + unregister_reboot_notifier(&pc87413_notifier); + release_region(swc_base_addr, 0x20); + + pr_info("watchdog component driver removed\n"); +} + +module_init(pc87413_init); +module_exit(pc87413_exit); + +MODULE_AUTHOR("Sven Anders <anders@anduras.de>, " + "Marcus Junker <junker@anduras.de>,"); +MODULE_DESCRIPTION("PC87413 WDT driver"); +MODULE_LICENSE("GPL"); + +MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); + +module_param(io, int, 0); +MODULE_PARM_DESC(io, MODNAME " I/O port (default: " + __MODULE_STRING(IO_DEFAULT) ")."); + +module_param(timeout, int, 0); +MODULE_PARM_DESC(timeout, + "Watchdog timeout in minutes (default=" + __MODULE_STRING(DEFAULT_TIMEOUT) ")."); + +module_param(nowayout, bool, 0); +MODULE_PARM_DESC(nowayout, + "Watchdog cannot be stopped once started (default=" + __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); + |