diff options
Diffstat (limited to 'drivers/char/watchdog/pcwd.c')
| -rw-r--r-- | drivers/char/watchdog/pcwd.c | 926 |
1 files changed, 926 insertions, 0 deletions
diff --git a/drivers/char/watchdog/pcwd.c b/drivers/char/watchdog/pcwd.c new file mode 100644 index 000000000000..592dca108866 --- /dev/null +++ b/drivers/char/watchdog/pcwd.c @@ -0,0 +1,926 @@ +/* + * PC Watchdog Driver + * by Ken Hollis (khollis@bitgate.com) + * + * Permission granted from Simon Machell (73244.1270@compuserve.com) + * Written for the Linux Kernel, and GPLed by Ken Hollis + * + * 960107 Added request_region routines, modulized the whole thing. + * 960108 Fixed end-of-file pointer (Thanks to Dan Hollis), added + * WD_TIMEOUT define. + * 960216 Added eof marker on the file, and changed verbose messages. + * 960716 Made functional and cosmetic changes to the source for + * inclusion in Linux 2.0.x kernels, thanks to Alan Cox. + * 960717 Removed read/seek routines, replaced with ioctl. Also, added + * check_region command due to Alan's suggestion. + * 960821 Made changes to compile in newer 2.0.x kernels. Added + * "cold reboot sense" entry. + * 960825 Made a few changes to code, deleted some defines and made + * typedefs to replace them. Made heartbeat reset only available + * via ioctl, and removed the write routine. + * 960828 Added new items for PC Watchdog Rev.C card. + * 960829 Changed around all of the IOCTLs, added new features, + * added watchdog disable/re-enable routines. Added firmware + * version reporting. Added read routine for temperature. + * Removed some extra defines, added an autodetect Revision + * routine. + * 961006 Revised some documentation, fixed some cosmetic bugs. Made + * drivers to panic the system if it's overheating at bootup. + * 961118 Changed some verbiage on some of the output, tidied up + * code bits, and added compatibility to 2.1.x. + * 970912 Enabled board on open and disable on close. + * 971107 Took account of recent VFS changes (broke read). + * 971210 Disable board on initialisation in case board already ticking. + * 971222 Changed open/close for temperature handling + * Michael Meskes <meskes@debian.org>. + * 980112 Used minor numbers from include/linux/miscdevice.h + * 990403 Clear reset status after reading control status register in + * pcwd_showprevstate(). [Marc Boucher <marc@mbsi.ca>] + * 990605 Made changes to code to support Firmware 1.22a, added + * fairly useless proc entry. + * 990610 removed said useless proc code for the merge <alan> + * 000403 Removed last traces of proc code. <davej> + * 011214 Added nowayout module option to override CONFIG_WATCHDOG_NOWAYOUT <Matt_Domsch@dell.com> + * Added timeout module option to override default + */ + +/* + * A bells and whistles driver is available from http://www.pcwd.de/ + * More info available at http://www.berkprod.com/ or http://www.pcwatchdog.com/ + */ + +#include <linux/module.h> +#include <linux/moduleparam.h> +#include <linux/types.h> +#include <linux/timer.h> +#include <linux/jiffies.h> +#include <linux/config.h> +#include <linux/wait.h> +#include <linux/slab.h> +#include <linux/ioport.h> +#include <linux/delay.h> +#include <linux/fs.h> +#include <linux/miscdevice.h> +#include <linux/watchdog.h> +#include <linux/notifier.h> +#include <linux/init.h> +#include <linux/spinlock.h> +#include <linux/reboot.h> + +#include <asm/uaccess.h> +#include <asm/io.h> + +#define WD_VER "1.16 (06/12/2004)" +#define PFX "pcwd: " + +/* + * It should be noted that PCWD_REVISION_B was removed because A and B + * are essentially the same types of card, with the exception that B + * has temperature reporting. Since I didn't receive a Rev.B card, + * the Rev.B card is not supported. (It's a good thing too, as they + * are no longer in production.) + */ +#define PCWD_REVISION_A 1 +#define PCWD_REVISION_C 2 + +/* + * These are the defines that describe the control status bits for the + * PC Watchdog card, revision A. + */ +#define WD_WDRST 0x01 /* Previously reset state */ +#define WD_T110 0x02 /* Temperature overheat sense */ +#define WD_HRTBT 0x04 /* Heartbeat sense */ +#define WD_RLY2 0x08 /* External relay triggered */ +#define WD_SRLY2 0x80 /* Software external relay triggered */ + +/* + * These are the defines that describe the control status bits for the + * PC Watchdog card, revision C. + */ +#define WD_REVC_WTRP 0x01 /* Watchdog Trip status */ +#define WD_REVC_HRBT 0x02 /* Watchdog Heartbeat */ +#define WD_REVC_TTRP 0x04 /* Temperature Trip status */ + +/* max. time we give an ISA watchdog card to process a command */ +/* 500ms for each 4 bit response (according to spec.) */ +#define ISA_COMMAND_TIMEOUT 1000 + +/* Watchdog's internal commands */ +#define CMD_ISA_IDLE 0x00 +#define CMD_ISA_VERSION_INTEGER 0x01 +#define CMD_ISA_VERSION_TENTH 0x02 +#define CMD_ISA_VERSION_HUNDRETH 0x03 +#define CMD_ISA_VERSION_MINOR 0x04 +#define CMD_ISA_SWITCH_SETTINGS 0x05 +#define CMD_ISA_DELAY_TIME_2SECS 0x0A +#define CMD_ISA_DELAY_TIME_4SECS 0x0B +#define CMD_ISA_DELAY_TIME_8SECS 0x0C + +/* + * We are using an kernel timer to do the pinging of the watchdog + * every ~500ms. We try to set the internal heartbeat of the + * watchdog to 2 ms. + */ + +#define WDT_INTERVAL (HZ/2+1) + +/* We can only use 1 card due to the /dev/watchdog restriction */ +static int cards_found; + +/* internal variables */ +static atomic_t open_allowed = ATOMIC_INIT(1); +static char expect_close; +static struct timer_list timer; +static unsigned long next_heartbeat; +static int temp_panic; +static int revision; /* The card's revision */ +static int supports_temp; /* Wether or not the card has a temperature device */ +static int command_mode; /* Wether or not the card is in command mode */ +static int initial_status; /* The card's boot status */ +static int current_readport; /* The cards I/O address */ +static spinlock_t io_lock; + +/* module parameters */ +#define WATCHDOG_HEARTBEAT 60 /* 60 sec default heartbeat */ +static int heartbeat = WATCHDOG_HEARTBEAT; +module_param(heartbeat, int, 0); +MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat in seconds. (2<=heartbeat<=7200, default=" __MODULE_STRING(WATCHDOG_HEARTBEAT) ")"); + +#ifdef CONFIG_WATCHDOG_NOWAYOUT +static int nowayout = 1; +#else +static int nowayout = 0; +#endif + +module_param(nowayout, int, 0); +MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=CONFIG_WATCHDOG_NOWAYOUT)"); + +/* + * Internal functions + */ + +static int send_isa_command(int cmd) +{ + int i; + int control_status; + int port0, last_port0; /* Double read for stabilising */ + + /* The WCMD bit must be 1 and the command is only 4 bits in size */ + control_status = (cmd & 0x0F) | 0x80; + outb_p(control_status, current_readport + 2); + udelay(ISA_COMMAND_TIMEOUT); + + port0 = inb_p(current_readport); + for (i = 0; i < 25; ++i) { + last_port0 = port0; + port0 = inb_p(current_readport); + + if (port0 == last_port0) + break; /* Data is stable */ + + udelay (250); + } + + return port0; +} + +static int set_command_mode(void) +{ + int i, found=0, count=0; + + /* Set the card into command mode */ + spin_lock(&io_lock); + while ((!found) && (count < 3)) { + i = send_isa_command(CMD_ISA_IDLE); + + if (i == 0x00) + found = 1; + else if (i == 0xF3) { + /* Card does not like what we've done to it */ + outb_p(0x00, current_readport + 2); + udelay(1200); /* Spec says wait 1ms */ + outb_p(0x00, current_readport + 2); + udelay(ISA_COMMAND_TIMEOUT); + } + count++; + } + spin_unlock(&io_lock); + command_mode = found; + + return(found); +} + +static void unset_command_mode(void) +{ + /* Set the card into normal mode */ + spin_lock(&io_lock); + outb_p(0x00, current_readport + 2); + udelay(ISA_COMMAND_TIMEOUT); + spin_unlock(&io_lock); + + command_mode = 0; +} + +static void pcwd_timer_ping(unsigned long data) +{ + int wdrst_stat; + + /* If we got a heartbeat pulse within the WDT_INTERVAL + * we agree to ping the WDT */ + if(time_before(jiffies, next_heartbeat)) { + /* Ping the watchdog */ + spin_lock(&io_lock); + if (revision == PCWD_REVISION_A) { + /* Rev A cards are reset by setting the WD_WDRST bit in register 1 */ + wdrst_stat = inb_p(current_readport); + wdrst_stat &= 0x0F; + wdrst_stat |= WD_WDRST; + + outb_p(wdrst_stat, current_readport + 1); + } else { + /* Re-trigger watchdog by writing to port 0 */ + outb_p(0x00, current_readport); + } + + /* Re-set the timer interval */ + mod_timer(&timer, jiffies + WDT_INTERVAL); + + spin_unlock(&io_lock); + } else { + printk(KERN_WARNING PFX "Heartbeat lost! Will not ping the watchdog\n"); + } +} + +static int pcwd_start(void) +{ + int stat_reg; + + next_heartbeat = jiffies + (heartbeat * HZ); + + /* Start the timer */ + mod_timer(&timer, jiffies + WDT_INTERVAL); + + /* Enable the port */ + if (revision == PCWD_REVISION_C) { + spin_lock(&io_lock); + outb_p(0x00, current_readport + 3); + udelay(ISA_COMMAND_TIMEOUT); + stat_reg = inb_p(current_readport + 2); + spin_unlock(&io_lock); + if (stat_reg & 0x10) { + printk(KERN_INFO PFX "Could not start watchdog\n"); + return -EIO; + } + } + return 0; +} + +static int pcwd_stop(void) +{ + int stat_reg; + + /* Stop the timer */ + del_timer(&timer); + + /* Disable the board */ + if (revision == PCWD_REVISION_C) { + spin_lock(&io_lock); + outb_p(0xA5, current_readport + 3); + udelay(ISA_COMMAND_TIMEOUT); + outb_p(0xA5, current_readport + 3); + udelay(ISA_COMMAND_TIMEOUT); + stat_reg = inb_p(current_readport + 2); + spin_unlock(&io_lock); + if ((stat_reg & 0x10) == 0) { + printk(KERN_INFO PFX "Could not stop watchdog\n"); + return -EIO; + } + } + return 0; +} + +static int pcwd_keepalive(void) +{ + /* user land ping */ + next_heartbeat = jiffies + (heartbeat * HZ); + return 0; +} + +static int pcwd_set_heartbeat(int t) +{ + if ((t < 2) || (t > 7200)) /* arbitrary upper limit */ + return -EINVAL; + + heartbeat = t; + return 0; +} + +static int pcwd_get_status(int *status) +{ + int card_status; + + *status=0; + spin_lock(&io_lock); + if (revision == PCWD_REVISION_A) + /* Rev A cards return status information from + * the base register, which is used for the + * temperature in other cards. */ + card_status = inb(current_readport); + else { + /* Rev C cards return card status in the base + * address + 1 register. And use different bits + * to indicate a card initiated reset, and an + * over-temperature condition. And the reboot + * status can be reset. */ + card_status = inb(current_readport + 1); + } + spin_unlock(&io_lock); + + if (revision == PCWD_REVISION_A) { + if (card_status & WD_WDRST) + *status |= WDIOF_CARDRESET; + + if (card_status & WD_T110) { + *status |= WDIOF_OVERHEAT; + if (temp_panic) { + printk (KERN_INFO PFX "Temperature overheat trip!\n"); + machine_power_off(); + } + } + } else { + if (card_status & WD_REVC_WTRP) + *status |= WDIOF_CARDRESET; + + if (card_status & WD_REVC_TTRP) { + *status |= WDIOF_OVERHEAT; + if (temp_panic) { + printk (KERN_INFO PFX "Temperature overheat trip!\n"); + machine_power_off(); + } + } + } + + return 0; +} + +static int pcwd_clear_status(void) +{ + if (revision == PCWD_REVISION_C) { + spin_lock(&io_lock); + outb_p(0x00, current_readport + 1); /* clear reset status */ + spin_unlock(&io_lock); + } + return 0; +} + +static int pcwd_get_temperature(int *temperature) +{ + /* check that port 0 gives temperature info and no command results */ + if (command_mode) + return -1; + + *temperature = 0; + if (!supports_temp) + return -ENODEV; + + /* + * Convert celsius to fahrenheit, since this was + * the decided 'standard' for this return value. + */ + spin_lock(&io_lock); + *temperature = ((inb(current_readport)) * 9 / 5) + 32; + spin_unlock(&io_lock); + + return 0; +} + +/* + * /dev/watchdog handling + */ + +static int pcwd_ioctl(struct inode *inode, struct file *file, + unsigned int cmd, unsigned long arg) +{ + int rv; + int status; + int temperature; + int new_heartbeat; + int __user *argp = (int __user *)arg; + static struct watchdog_info ident = { + .options = WDIOF_OVERHEAT | + WDIOF_CARDRESET | + WDIOF_KEEPALIVEPING | + WDIOF_SETTIMEOUT | + WDIOF_MAGICCLOSE, + .firmware_version = 1, + .identity = "PCWD", + }; + + switch(cmd) { + default: + return -ENOIOCTLCMD; + + case WDIOC_GETSUPPORT: + if(copy_to_user(argp, &ident, sizeof(ident))) + return -EFAULT; + return 0; + + case WDIOC_GETSTATUS: + pcwd_get_status(&status); + return put_user(status, argp); + + case WDIOC_GETBOOTSTATUS: + return put_user(initial_status, argp); + + case WDIOC_GETTEMP: + if (pcwd_get_temperature(&temperature)) + return -EFAULT; + + return put_user(temperature, argp); + + case WDIOC_SETOPTIONS: + if (revision == PCWD_REVISION_C) + { + if(copy_from_user(&rv, argp, sizeof(int))) + return -EFAULT; + + if (rv & WDIOS_DISABLECARD) + { + return pcwd_stop(); + } + + if (rv & WDIOS_ENABLECARD) + { + return pcwd_start(); + } + + if (rv & WDIOS_TEMPPANIC) + { + temp_panic = 1; + } + } + return -EINVAL; + + case WDIOC_KEEPALIVE: + pcwd_keepalive(); + return 0; + + case WDIOC_SETTIMEOUT: + if (get_user(new_heartbeat, argp)) + return -EFAULT; + + if (pcwd_set_heartbeat(new_heartbeat)) + return -EINVAL; + + pcwd_keepalive(); + /* Fall */ + + case WDIOC_GETTIMEOUT: + return put_user(heartbeat, argp); + } + + return 0; +} + +static ssize_t pcwd_write(struct file *file, const char __user *buf, size_t len, + loff_t *ppos) +{ + if (len) { + if (!nowayout) { + size_t i; + + /* In case it was set long ago */ + expect_close = 0; + + for (i = 0; i != len; i++) { + char c; + + if (get_user(c, buf + i)) + return -EFAULT; + if (c == 'V') + expect_close = 42; + } + } + pcwd_keepalive(); + } + return len; +} + +static int pcwd_open(struct inode *inode, struct file *file) +{ + if (!atomic_dec_and_test(&open_allowed) ) { + atomic_inc( &open_allowed ); + return -EBUSY; + } + + if (nowayout) + __module_get(THIS_MODULE); + + /* Activate */ + pcwd_start(); + pcwd_keepalive(); + return nonseekable_open(inode, file); +} + +static int pcwd_close(struct inode *inode, struct file *file) +{ + if (expect_close == 42) { + pcwd_stop(); + } else { + printk(KERN_CRIT PFX "Unexpected close, not stopping watchdog!\n"); + pcwd_keepalive(); + } + expect_close = 0; + atomic_inc( &open_allowed ); + return 0; +} + +/* + * /dev/temperature handling + */ + +static ssize_t pcwd_temp_read(struct file *file, char __user *buf, size_t count, + loff_t *ppos) +{ + int temperature; + + if (pcwd_get_temperature(&temperature)) + return -EFAULT; + + if (copy_to_user(buf, &temperature, 1)) + return -EFAULT; + + return 1; +} + +static int pcwd_temp_open(struct inode *inode, struct file *file) +{ + if (!supports_temp) + return -ENODEV; + + return nonseekable_open(inode, file); +} + +static int pcwd_temp_close(struct inode *inode, struct file *file) +{ + return 0; +} + +/* + * Notify system + */ + +static int pcwd_notify_sys(struct notifier_block *this, unsigned long code, void *unused) +{ + if (code==SYS_DOWN || code==SYS_HALT) { + /* Turn the WDT off */ + pcwd_stop(); + } + + return NOTIFY_DONE; +} + +/* + * Kernel Interfaces + */ + +static struct file_operations pcwd_fops = { + .owner = THIS_MODULE, + .llseek = no_llseek, + .write = pcwd_write, + .ioctl = pcwd_ioctl, + .open = pcwd_open, + .release = pcwd_close, +}; + +static struct miscdevice pcwd_miscdev = { + .minor = WATCHDOG_MINOR, + .name = "watchdog", + .fops = &pcwd_fops, +}; + +static struct file_operations pcwd_temp_fops = { + .owner = THIS_MODULE, + .llseek = no_llseek, + .read = pcwd_temp_read, + .open = pcwd_temp_open, + .release = pcwd_temp_close, +}; + +static struct miscdevice temp_miscdev = { + .minor = TEMP_MINOR, + .name = "temperature", + .fops = &pcwd_temp_fops, +}; + +static struct notifier_block pcwd_notifier = { + .notifier_call = pcwd_notify_sys, +}; + +/* + * Init & exit routines + */ + +static inline void get_support(void) +{ + if (inb(current_readport) != 0xF0) + supports_temp = 1; +} + +static inline int get_revision(void) +{ + int r = PCWD_REVISION_C; + + spin_lock(&io_lock); + /* REV A cards use only 2 io ports; test + * presumes a floating bus reads as 0xff. */ + if ((inb(current_readport + 2) == 0xFF) || + (inb(current_readport + 3) == 0xFF)) + r=PCWD_REVISION_A; + spin_unlock(&io_lock); + + return r; +} + +static inline char *get_firmware(void) +{ + int one, ten, hund, minor; + char *ret; + + ret = kmalloc(6, GFP_KERNEL); + if(ret == NULL) + return NULL; + + if (set_command_mode()) { + one = send_isa_command(CMD_ISA_VERSION_INTEGER); + ten = send_isa_command(CMD_ISA_VERSION_TENTH); + hund = send_isa_command(CMD_ISA_VERSION_HUNDRETH); + minor = send_isa_command(CMD_ISA_VERSION_MINOR); + sprintf(ret, "%c.%c%c%c", one, ten, hund, minor); + } + else + sprintf(ret, "ERROR"); + + unset_command_mode(); + return(ret); +} + +static inline int get_option_switches(void) +{ + int rv=0; + + if (set_command_mode()) { + /* Get switch settings */ + rv = send_isa_command(CMD_ISA_SWITCH_SETTINGS); + } + + unset_command_mode(); + return(rv); +} + +static int __devinit pcwatchdog_init(int base_addr) +{ + int ret; + char *firmware; + int option_switches; + + cards_found++; + if (cards_found == 1) + printk(KERN_INFO PFX "v%s Ken Hollis (kenji@bitgate.com)\n", WD_VER); + + if (cards_found > 1) { + printk(KERN_ERR PFX "This driver only supports 1 device\n"); + return -ENODEV; + } + + if (base_addr == 0x0000) { + printk(KERN_ERR PFX "No I/O-Address for card detected\n"); + return -ENODEV; + } + current_readport = base_addr; + + /* Check card's revision */ + revision = get_revision(); + + if (!request_region(current_readport, (revision == PCWD_REVISION_A) ? 2 : 4, "PCWD")) { + printk(KERN_ERR PFX "I/O address 0x%04x already in use\n", + current_readport); + current_readport = 0x0000; + return -EIO; + } + + /* Initial variables */ + supports_temp = 0; + temp_panic = 0; + initial_status = 0x0000; + + /* get the boot_status */ + pcwd_get_status(&initial_status); + + /* clear the "card caused reboot" flag */ + pcwd_clear_status(); + + init_timer(&timer); + timer.function = pcwd_timer_ping; + timer.data = 0; + + /* Disable the board */ + pcwd_stop(); + + /* Check whether or not the card supports the temperature device */ + get_support(); + + /* Get some extra info from the hardware (in command/debug/diag mode) */ + if (revision == PCWD_REVISION_A) + printk(KERN_INFO PFX "ISA-PC Watchdog (REV.A) detected at port 0x%04x\n", current_readport); + else if (revision == PCWD_REVISION_C) { + firmware = get_firmware(); + printk(KERN_INFO PFX "ISA-PC Watchdog (REV.C) detected at port 0x%04x (Firmware version: %s)\n", + current_readport, firmware); + kfree(firmware); + option_switches = get_option_switches(); + printk(KERN_INFO PFX "Option switches (0x%02x): Temperature Reset Enable=%s, Power On Delay=%s\n", + option_switches, + ((option_switches & 0x10) ? "ON" : "OFF"), + ((option_switches & 0x08) ? "ON" : "OFF")); + + /* Reprogram internal heartbeat to 2 seconds */ + if (set_command_mode()) { + send_isa_command(CMD_ISA_DELAY_TIME_2SECS); + unset_command_mode(); + } + } else { + /* Should NEVER happen, unless get_revision() fails. */ + printk(KERN_INFO PFX "Unable to get revision\n"); + release_region(current_readport, (revision == PCWD_REVISION_A) ? 2 : 4); + current_readport = 0x0000; + return -1; + } + + if (supports_temp) + printk(KERN_INFO PFX "Temperature Option Detected\n"); + + if (initial_status & WDIOF_CARDRESET) + printk(KERN_INFO PFX "Previous reboot was caused by the card\n"); + + if (initial_status & WDIOF_OVERHEAT) { + printk(KERN_EMERG PFX "Card senses a CPU Overheat. Panicking!\n"); + printk(KERN_EMERG PFX "CPU Overheat\n"); + } + + if (initial_status == 0) + printk(KERN_INFO PFX "No previous trip detected - Cold boot or reset\n"); + + /* Check that the heartbeat value is within it's range ; if not reset to the default */ + if (pcwd_set_heartbeat(heartbeat)) { + pcwd_set_heartbeat(WATCHDOG_HEARTBEAT); + printk(KERN_INFO PFX "heartbeat value must be 2<=heartbeat<=7200, using %d\n", + WATCHDOG_HEARTBEAT); + } + + ret = register_reboot_notifier(&pcwd_notifier); + if (ret) { + printk(KERN_ERR PFX "cannot register reboot notifier (err=%d)\n", + ret); + release_region(current_readport, (revision == PCWD_REVISION_A) ? 2 : 4); + current_readport = 0x0000; + return ret; + } + + if (supports_temp) { + ret = misc_register(&temp_miscdev); + if (ret) { + printk(KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n", + TEMP_MINOR, ret); + unregister_reboot_notifier(&pcwd_notifier); + release_region(current_readport, (revision == PCWD_REVISION_A) ? 2 : 4); + current_readport = 0x0000; + return ret; + } + } + + ret = misc_register(&pcwd_miscdev); + if (ret) { + printk(KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n", + WATCHDOG_MINOR, ret); + if (supports_temp) + misc_deregister(&temp_miscdev); + unregister_reboot_notifier(&pcwd_notifier); + release_region(current_readport, (revision == PCWD_REVISION_A) ? 2 : 4); + current_readport = 0x0000; + return ret; + } + + printk(KERN_INFO PFX "initialized. heartbeat=%d sec (nowayout=%d)\n", + heartbeat, nowayout); + + return 0; +} + +static void __devexit pcwatchdog_exit(void) +{ + /* Disable the board */ + if (!nowayout) + pcwd_stop(); + + /* Deregister */ + misc_deregister(&pcwd_miscdev); + if (supports_temp) + misc_deregister(&temp_miscdev); + unregister_reboot_notifier(&pcwd_notifier); + release_region(current_readport, (revision == PCWD_REVISION_A) ? 2 : 4); + current_readport = 0x0000; +} + +/* + * The ISA cards have a heartbeat bit in one of the registers, which + * register is card dependent. The heartbeat bit is monitored, and if + * found, is considered proof that a Berkshire card has been found. + * The initial rate is once per second at board start up, then twice + * per second for normal operation. + */ +static int __init pcwd_checkcard(int base_addr) +{ + int port0, last_port0; /* Reg 0, in case it's REV A */ + int port1, last_port1; /* Register 1 for REV C cards */ + int i; + int retval; + + if (!request_region (base_addr, 4, "PCWD")) { + printk (KERN_INFO PFX "Port 0x%04x unavailable\n", base_addr); + return 0; + } + + retval = 0; + + port0 = inb_p(base_addr); /* For REV A boards */ + port1 = inb_p(base_addr + 1); /* For REV C boards */ + if (port0 != 0xff || port1 != 0xff) { + /* Not an 'ff' from a floating bus, so must be a card! */ + for (i = 0; i < 4; ++i) { + + msleep(500); + + last_port0 = port0; + last_port1 = port1; + + port0 = inb_p(base_addr); + port1 = inb_p(base_addr + 1); + + /* Has either hearbeat bit changed? */ + if ((port0 ^ last_port0) & WD_HRTBT || + (port1 ^ last_port1) & WD_REVC_HRBT) { + retval = 1; + break; + } + } + } + release_region (base_addr, 4); + + return retval; +} + +/* + * These are the auto-probe addresses available. + * + * Revision A only uses ports 0x270 and 0x370. Revision C introduced 0x350. + * Revision A has an address range of 2 addresses, while Revision C has 4. + */ +static int pcwd_ioports[] = { 0x270, 0x350, 0x370, 0x000 }; + +static int __init pcwd_init_module(void) +{ + int i, found = 0; + + spin_lock_init(&io_lock); + + for (i = 0; pcwd_ioports[i] != 0; i++) { + if (pcwd_checkcard(pcwd_ioports[i])) { + if (!(pcwatchdog_init(pcwd_ioports[i]))) + found++; + } + } + + if (!found) { + printk (KERN_INFO PFX "No card detected, or port not available\n"); + return -ENODEV; + } + + return 0; +} + +static void __exit pcwd_cleanup_module(void) +{ + if (current_readport) + pcwatchdog_exit(); + return; +} + +module_init(pcwd_init_module); +module_exit(pcwd_cleanup_module); + +MODULE_AUTHOR("Ken Hollis <kenji@bitgate.com>"); +MODULE_DESCRIPTION("Berkshire ISA-PC Watchdog driver"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); +MODULE_ALIAS_MISCDEV(TEMP_MINOR); |