Back to home page

OSCL-LXR
 
 

     

0001 // SPDX-License-Identifier: GPL-2.0-only
0002 /*
0003  * PC Watchdog Driver
0004  * by Ken Hollis (khollis@bitgate.com)
0005  *
0006  * Permission granted from Simon Machell (smachell@berkprod.com)
0007  * Written for the Linux Kernel, and GPLed by Ken Hollis
0008  *
0009  * 960107   Added request_region routines, modulized the whole thing.
0010  * 960108   Fixed end-of-file pointer (Thanks to Dan Hollis), added
0011  *      WD_TIMEOUT define.
0012  * 960216   Added eof marker on the file, and changed verbose messages.
0013  * 960716   Made functional and cosmetic changes to the source for
0014  *      inclusion in Linux 2.0.x kernels, thanks to Alan Cox.
0015  * 960717   Removed read/seek routines, replaced with ioctl.  Also, added
0016  *      check_region command due to Alan's suggestion.
0017  * 960821   Made changes to compile in newer 2.0.x kernels.  Added
0018  *      "cold reboot sense" entry.
0019  * 960825   Made a few changes to code, deleted some defines and made
0020  *      typedefs to replace them.  Made heartbeat reset only available
0021  *      via ioctl, and removed the write routine.
0022  * 960828   Added new items for PC Watchdog Rev.C card.
0023  * 960829   Changed around all of the IOCTLs, added new features,
0024  *      added watchdog disable/re-enable routines.  Added firmware
0025  *      version reporting.  Added read routine for temperature.
0026  *      Removed some extra defines, added an autodetect Revision
0027  *      routine.
0028  * 961006   Revised some documentation, fixed some cosmetic bugs.  Made
0029  *      drivers to panic the system if it's overheating at bootup.
0030  * 961118   Changed some verbiage on some of the output, tidied up
0031  *      code bits, and added compatibility to 2.1.x.
0032  * 970912   Enabled board on open and disable on close.
0033  * 971107   Took account of recent VFS changes (broke read).
0034  * 971210   Disable board on initialisation in case board already ticking.
0035  * 971222   Changed open/close for temperature handling
0036  *      Michael Meskes <meskes@debian.org>.
0037  * 980112   Used minor numbers from include/linux/miscdevice.h
0038  * 990403   Clear reset status after reading control status register in
0039  *      pcwd_showprevstate(). [Marc Boucher <marc@mbsi.ca>]
0040  * 990605   Made changes to code to support Firmware 1.22a, added
0041  *      fairly useless proc entry.
0042  * 990610   removed said useless proc code for the merge <alan>
0043  * 000403   Removed last traces of proc code. <davej>
0044  * 011214   Added nowayout module option to override
0045  *      CONFIG_WATCHDOG_NOWAYOUT <Matt_Domsch@dell.com>
0046  *      Added timeout module option to override default
0047  */
0048 
0049 /*
0050  *  A bells and whistles driver is available from http://www.pcwd.de/
0051  *  More info available at http://www.berkprod.com/ or
0052  *  http://www.pcwatchdog.com/
0053  */
0054 
0055 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
0056 
0057 #include <linux/module.h>   /* For module specific items */
0058 #include <linux/moduleparam.h>  /* For new moduleparam's */
0059 #include <linux/types.h>    /* For standard types (like size_t) */
0060 #include <linux/errno.h>    /* For the -ENODEV/... values */
0061 #include <linux/kernel.h>   /* For printk/panic/... */
0062 #include <linux/delay.h>    /* For mdelay function */
0063 #include <linux/timer.h>    /* For timer related operations */
0064 #include <linux/jiffies.h>  /* For jiffies stuff */
0065 #include <linux/miscdevice.h>   /* For struct miscdevice */
0066 #include <linux/watchdog.h> /* For the watchdog specific items */
0067 #include <linux/reboot.h>   /* For kernel_power_off() */
0068 #include <linux/init.h>     /* For __init/__exit/... */
0069 #include <linux/fs.h>       /* For file operations */
0070 #include <linux/isa.h>      /* For isa devices */
0071 #include <linux/ioport.h>   /* For io-port access */
0072 #include <linux/spinlock.h> /* For spin_lock/spin_unlock/... */
0073 #include <linux/uaccess.h>  /* For copy_to_user/put_user/... */
0074 #include <linux/io.h>       /* For inb/outb/... */
0075 
0076 /* Module and version information */
0077 #define WATCHDOG_VERSION "1.20"
0078 #define WATCHDOG_DATE "18 Feb 2007"
0079 #define WATCHDOG_DRIVER_NAME "ISA-PC Watchdog"
0080 #define WATCHDOG_NAME "pcwd"
0081 #define DRIVER_VERSION WATCHDOG_DRIVER_NAME " driver, v" WATCHDOG_VERSION "\n"
0082 
0083 /*
0084  * It should be noted that PCWD_REVISION_B was removed because A and B
0085  * are essentially the same types of card, with the exception that B
0086  * has temperature reporting.  Since I didn't receive a Rev.B card,
0087  * the Rev.B card is not supported.  (It's a good thing too, as they
0088  * are no longer in production.)
0089  */
0090 #define PCWD_REVISION_A     1
0091 #define PCWD_REVISION_C     2
0092 
0093 /*
0094  * These are the auto-probe addresses available.
0095  *
0096  * Revision A only uses ports 0x270 and 0x370.  Revision C introduced 0x350.
0097  * Revision A has an address range of 2 addresses, while Revision C has 4.
0098  */
0099 #define PCWD_ISA_NR_CARDS   3
0100 static int pcwd_ioports[] = { 0x270, 0x350, 0x370, 0x000 };
0101 
0102 /*
0103  * These are the defines that describe the control status bits for the
0104  * PCI-PC Watchdog card.
0105 */
0106 /* Port 1 : Control Status #1 for the PC Watchdog card, revision A. */
0107 #define WD_WDRST        0x01    /* Previously reset state */
0108 #define WD_T110         0x02    /* Temperature overheat sense */
0109 #define WD_HRTBT        0x04    /* Heartbeat sense */
0110 #define WD_RLY2         0x08    /* External relay triggered */
0111 #define WD_SRLY2        0x80    /* Software external relay triggered */
0112 /* Port 1 : Control Status #1 for the PC Watchdog card, revision C. */
0113 #define WD_REVC_WTRP        0x01    /* Watchdog Trip status */
0114 #define WD_REVC_HRBT        0x02    /* Watchdog Heartbeat */
0115 #define WD_REVC_TTRP        0x04    /* Temperature Trip status */
0116 #define WD_REVC_RL2A        0x08    /* Relay 2 activated by
0117                             on-board processor */
0118 #define WD_REVC_RL1A        0x10    /* Relay 1 active */
0119 #define WD_REVC_R2DS        0x40    /* Relay 2 disable */
0120 #define WD_REVC_RLY2        0x80    /* Relay 2 activated? */
0121 /* Port 2 : Control Status #2 */
0122 #define WD_WDIS         0x10    /* Watchdog Disabled */
0123 #define WD_ENTP         0x20    /* Watchdog Enable Temperature Trip */
0124 #define WD_SSEL         0x40    /* Watchdog Switch Select
0125                             (1:SW1 <-> 0:SW2) */
0126 #define WD_WCMD         0x80    /* Watchdog Command Mode */
0127 
0128 /* max. time we give an ISA watchdog card to process a command */
0129 /* 500ms for each 4 bit response (according to spec.) */
0130 #define ISA_COMMAND_TIMEOUT     1000
0131 
0132 /* Watchdog's internal commands */
0133 #define CMD_ISA_IDLE            0x00
0134 #define CMD_ISA_VERSION_INTEGER     0x01
0135 #define CMD_ISA_VERSION_TENTH       0x02
0136 #define CMD_ISA_VERSION_HUNDRETH    0x03
0137 #define CMD_ISA_VERSION_MINOR       0x04
0138 #define CMD_ISA_SWITCH_SETTINGS     0x05
0139 #define CMD_ISA_RESET_PC        0x06
0140 #define CMD_ISA_ARM_0           0x07
0141 #define CMD_ISA_ARM_30          0x08
0142 #define CMD_ISA_ARM_60          0x09
0143 #define CMD_ISA_DELAY_TIME_2SECS    0x0A
0144 #define CMD_ISA_DELAY_TIME_4SECS    0x0B
0145 #define CMD_ISA_DELAY_TIME_8SECS    0x0C
0146 #define CMD_ISA_RESET_RELAYS        0x0D
0147 
0148 /* Watchdog's Dip Switch heartbeat values */
0149 static const int heartbeat_tbl[] = {
0150     20, /* OFF-OFF-OFF  = 20 Sec  */
0151     40, /* OFF-OFF-ON   = 40 Sec  */
0152     60, /* OFF-ON-OFF   =  1 Min  */
0153     300,    /* OFF-ON-ON    =  5 Min  */
0154     600,    /* ON-OFF-OFF   = 10 Min  */
0155     1800,   /* ON-OFF-ON    = 30 Min  */
0156     3600,   /* ON-ON-OFF    =  1 Hour */
0157     7200,   /* ON-ON-ON =  2 hour */
0158 };
0159 
0160 /*
0161  * We are using an kernel timer to do the pinging of the watchdog
0162  * every ~500ms. We try to set the internal heartbeat of the
0163  * watchdog to 2 ms.
0164  */
0165 
0166 #define WDT_INTERVAL (HZ/2+1)
0167 
0168 /* We can only use 1 card due to the /dev/watchdog restriction */
0169 static int cards_found;
0170 
0171 /* internal variables */
0172 static unsigned long open_allowed;
0173 static char expect_close;
0174 static int temp_panic;
0175 
0176 /* this is private data for each ISA-PC watchdog card */
0177 static struct {
0178     char fw_ver_str[6];     /* The cards firmware version */
0179     int revision;           /* The card's revision */
0180     int supports_temp;      /* Whether or not the card has
0181                         a temperature device */
0182     int command_mode;       /* Whether or not the card is in
0183                         command mode */
0184     int boot_status;        /* The card's boot status */
0185     int io_addr;            /* The cards I/O address */
0186     spinlock_t io_lock;     /* the lock for io operations */
0187     struct timer_list timer;    /* The timer that pings the watchdog */
0188     unsigned long next_heartbeat;   /* the next_heartbeat for the timer */
0189 } pcwd_private;
0190 
0191 /* module parameters */
0192 #define QUIET   0   /* Default */
0193 #define VERBOSE 1   /* Verbose */
0194 #define DEBUG   2   /* print fancy stuff too */
0195 static int debug = QUIET;
0196 module_param(debug, int, 0);
0197 MODULE_PARM_DESC(debug,
0198         "Debug level: 0=Quiet, 1=Verbose, 2=Debug (default=0)");
0199 
0200 /* default heartbeat = delay-time from dip-switches */
0201 #define WATCHDOG_HEARTBEAT 0
0202 static int heartbeat = WATCHDOG_HEARTBEAT;
0203 module_param(heartbeat, int, 0);
0204 MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat in seconds. "
0205     "(2 <= heartbeat <= 7200 or 0=delay-time from dip-switches, default="
0206                 __MODULE_STRING(WATCHDOG_HEARTBEAT) ")");
0207 
0208 static bool nowayout = WATCHDOG_NOWAYOUT;
0209 module_param(nowayout, bool, 0);
0210 MODULE_PARM_DESC(nowayout,
0211         "Watchdog cannot be stopped once started (default="
0212                 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
0213 
0214 /*
0215  *  Internal functions
0216  */
0217 
0218 static int send_isa_command(int cmd)
0219 {
0220     int i;
0221     int control_status;
0222     int port0, last_port0;  /* Double read for stabilising */
0223 
0224     if (debug >= DEBUG)
0225         pr_debug("sending following data cmd=0x%02x\n", cmd);
0226 
0227     /* The WCMD bit must be 1 and the command is only 4 bits in size */
0228     control_status = (cmd & 0x0F) | WD_WCMD;
0229     outb_p(control_status, pcwd_private.io_addr + 2);
0230     udelay(ISA_COMMAND_TIMEOUT);
0231 
0232     port0 = inb_p(pcwd_private.io_addr);
0233     for (i = 0; i < 25; ++i) {
0234         last_port0 = port0;
0235         port0 = inb_p(pcwd_private.io_addr);
0236 
0237         if (port0 == last_port0)
0238             break;  /* Data is stable */
0239 
0240         udelay(250);
0241     }
0242 
0243     if (debug >= DEBUG)
0244         pr_debug("received following data for cmd=0x%02x: port0=0x%02x last_port0=0x%02x\n",
0245              cmd, port0, last_port0);
0246 
0247     return port0;
0248 }
0249 
0250 static int set_command_mode(void)
0251 {
0252     int i, found = 0, count = 0;
0253 
0254     /* Set the card into command mode */
0255     spin_lock(&pcwd_private.io_lock);
0256     while ((!found) && (count < 3)) {
0257         i = send_isa_command(CMD_ISA_IDLE);
0258 
0259         if (i == 0x00)
0260             found = 1;
0261         else if (i == 0xF3) {
0262             /* Card does not like what we've done to it */
0263             outb_p(0x00, pcwd_private.io_addr + 2);
0264             udelay(1200);   /* Spec says wait 1ms */
0265             outb_p(0x00, pcwd_private.io_addr + 2);
0266             udelay(ISA_COMMAND_TIMEOUT);
0267         }
0268         count++;
0269     }
0270     spin_unlock(&pcwd_private.io_lock);
0271     pcwd_private.command_mode = found;
0272 
0273     if (debug >= DEBUG)
0274         pr_debug("command_mode=%d\n", pcwd_private.command_mode);
0275 
0276     return found;
0277 }
0278 
0279 static void unset_command_mode(void)
0280 {
0281     /* Set the card into normal mode */
0282     spin_lock(&pcwd_private.io_lock);
0283     outb_p(0x00, pcwd_private.io_addr + 2);
0284     udelay(ISA_COMMAND_TIMEOUT);
0285     spin_unlock(&pcwd_private.io_lock);
0286 
0287     pcwd_private.command_mode = 0;
0288 
0289     if (debug >= DEBUG)
0290         pr_debug("command_mode=%d\n", pcwd_private.command_mode);
0291 }
0292 
0293 static inline void pcwd_check_temperature_support(void)
0294 {
0295     if (inb(pcwd_private.io_addr) != 0xF0)
0296         pcwd_private.supports_temp = 1;
0297 }
0298 
0299 static inline void pcwd_get_firmware(void)
0300 {
0301     int one, ten, hund, minor;
0302 
0303     strcpy(pcwd_private.fw_ver_str, "ERROR");
0304 
0305     if (set_command_mode()) {
0306         one = send_isa_command(CMD_ISA_VERSION_INTEGER);
0307         ten = send_isa_command(CMD_ISA_VERSION_TENTH);
0308         hund = send_isa_command(CMD_ISA_VERSION_HUNDRETH);
0309         minor = send_isa_command(CMD_ISA_VERSION_MINOR);
0310         sprintf(pcwd_private.fw_ver_str, "%c.%c%c%c",
0311                     one, ten, hund, minor);
0312     }
0313     unset_command_mode();
0314 
0315     return;
0316 }
0317 
0318 static inline int pcwd_get_option_switches(void)
0319 {
0320     int option_switches = 0;
0321 
0322     if (set_command_mode()) {
0323         /* Get switch settings */
0324         option_switches = send_isa_command(CMD_ISA_SWITCH_SETTINGS);
0325     }
0326 
0327     unset_command_mode();
0328     return option_switches;
0329 }
0330 
0331 static void pcwd_show_card_info(void)
0332 {
0333     int option_switches;
0334 
0335     /* Get some extra info from the hardware (in command/debug/diag mode) */
0336     if (pcwd_private.revision == PCWD_REVISION_A)
0337         pr_info("ISA-PC Watchdog (REV.A) detected at port 0x%04x\n",
0338             pcwd_private.io_addr);
0339     else if (pcwd_private.revision == PCWD_REVISION_C) {
0340         pcwd_get_firmware();
0341         pr_info("ISA-PC Watchdog (REV.C) detected at port 0x%04x (Firmware version: %s)\n",
0342             pcwd_private.io_addr, pcwd_private.fw_ver_str);
0343         option_switches = pcwd_get_option_switches();
0344         pr_info("Option switches (0x%02x): Temperature Reset Enable=%s, Power On Delay=%s\n",
0345             option_switches,
0346             ((option_switches & 0x10) ? "ON" : "OFF"),
0347             ((option_switches & 0x08) ? "ON" : "OFF"));
0348 
0349         /* Reprogram internal heartbeat to 2 seconds */
0350         if (set_command_mode()) {
0351             send_isa_command(CMD_ISA_DELAY_TIME_2SECS);
0352             unset_command_mode();
0353         }
0354     }
0355 
0356     if (pcwd_private.supports_temp)
0357         pr_info("Temperature Option Detected\n");
0358 
0359     if (pcwd_private.boot_status & WDIOF_CARDRESET)
0360         pr_info("Previous reboot was caused by the card\n");
0361 
0362     if (pcwd_private.boot_status & WDIOF_OVERHEAT) {
0363         pr_emerg("Card senses a CPU Overheat. Panicking!\n");
0364         pr_emerg("CPU Overheat\n");
0365     }
0366 
0367     if (pcwd_private.boot_status == 0)
0368         pr_info("No previous trip detected - Cold boot or reset\n");
0369 }
0370 
0371 static void pcwd_timer_ping(struct timer_list *unused)
0372 {
0373     int wdrst_stat;
0374 
0375     /* If we got a heartbeat pulse within the WDT_INTERVAL
0376      * we agree to ping the WDT */
0377     if (time_before(jiffies, pcwd_private.next_heartbeat)) {
0378         /* Ping the watchdog */
0379         spin_lock(&pcwd_private.io_lock);
0380         if (pcwd_private.revision == PCWD_REVISION_A) {
0381             /*  Rev A cards are reset by setting the
0382                 WD_WDRST bit in register 1 */
0383             wdrst_stat = inb_p(pcwd_private.io_addr);
0384             wdrst_stat &= 0x0F;
0385             wdrst_stat |= WD_WDRST;
0386 
0387             outb_p(wdrst_stat, pcwd_private.io_addr + 1);
0388         } else {
0389             /* Re-trigger watchdog by writing to port 0 */
0390             outb_p(0x00, pcwd_private.io_addr);
0391         }
0392 
0393         /* Re-set the timer interval */
0394         mod_timer(&pcwd_private.timer, jiffies + WDT_INTERVAL);
0395 
0396         spin_unlock(&pcwd_private.io_lock);
0397     } else {
0398         pr_warn("Heartbeat lost! Will not ping the watchdog\n");
0399     }
0400 }
0401 
0402 static int pcwd_start(void)
0403 {
0404     int stat_reg;
0405 
0406     pcwd_private.next_heartbeat = jiffies + (heartbeat * HZ);
0407 
0408     /* Start the timer */
0409     mod_timer(&pcwd_private.timer, jiffies + WDT_INTERVAL);
0410 
0411     /* Enable the port */
0412     if (pcwd_private.revision == PCWD_REVISION_C) {
0413         spin_lock(&pcwd_private.io_lock);
0414         outb_p(0x00, pcwd_private.io_addr + 3);
0415         udelay(ISA_COMMAND_TIMEOUT);
0416         stat_reg = inb_p(pcwd_private.io_addr + 2);
0417         spin_unlock(&pcwd_private.io_lock);
0418         if (stat_reg & WD_WDIS) {
0419             pr_info("Could not start watchdog\n");
0420             return -EIO;
0421         }
0422     }
0423 
0424     if (debug >= VERBOSE)
0425         pr_debug("Watchdog started\n");
0426 
0427     return 0;
0428 }
0429 
0430 static int pcwd_stop(void)
0431 {
0432     int stat_reg;
0433 
0434     /* Stop the timer */
0435     del_timer(&pcwd_private.timer);
0436 
0437     /*  Disable the board  */
0438     if (pcwd_private.revision == PCWD_REVISION_C) {
0439         spin_lock(&pcwd_private.io_lock);
0440         outb_p(0xA5, pcwd_private.io_addr + 3);
0441         udelay(ISA_COMMAND_TIMEOUT);
0442         outb_p(0xA5, pcwd_private.io_addr + 3);
0443         udelay(ISA_COMMAND_TIMEOUT);
0444         stat_reg = inb_p(pcwd_private.io_addr + 2);
0445         spin_unlock(&pcwd_private.io_lock);
0446         if ((stat_reg & WD_WDIS) == 0) {
0447             pr_info("Could not stop watchdog\n");
0448             return -EIO;
0449         }
0450     }
0451 
0452     if (debug >= VERBOSE)
0453         pr_debug("Watchdog stopped\n");
0454 
0455     return 0;
0456 }
0457 
0458 static int pcwd_keepalive(void)
0459 {
0460     /* user land ping */
0461     pcwd_private.next_heartbeat = jiffies + (heartbeat * HZ);
0462 
0463     if (debug >= DEBUG)
0464         pr_debug("Watchdog keepalive signal send\n");
0465 
0466     return 0;
0467 }
0468 
0469 static int pcwd_set_heartbeat(int t)
0470 {
0471     if (t < 2 || t > 7200) /* arbitrary upper limit */
0472         return -EINVAL;
0473 
0474     heartbeat = t;
0475 
0476     if (debug >= VERBOSE)
0477         pr_debug("New heartbeat: %d\n", heartbeat);
0478 
0479     return 0;
0480 }
0481 
0482 static int pcwd_get_status(int *status)
0483 {
0484     int control_status;
0485 
0486     *status = 0;
0487     spin_lock(&pcwd_private.io_lock);
0488     if (pcwd_private.revision == PCWD_REVISION_A)
0489         /* Rev A cards return status information from
0490          * the base register, which is used for the
0491          * temperature in other cards. */
0492         control_status = inb(pcwd_private.io_addr);
0493     else {
0494         /* Rev C cards return card status in the base
0495          * address + 1 register. And use different bits
0496          * to indicate a card initiated reset, and an
0497          * over-temperature condition. And the reboot
0498          * status can be reset. */
0499         control_status = inb(pcwd_private.io_addr + 1);
0500     }
0501     spin_unlock(&pcwd_private.io_lock);
0502 
0503     if (pcwd_private.revision == PCWD_REVISION_A) {
0504         if (control_status & WD_WDRST)
0505             *status |= WDIOF_CARDRESET;
0506 
0507         if (control_status & WD_T110) {
0508             *status |= WDIOF_OVERHEAT;
0509             if (temp_panic) {
0510                 pr_info("Temperature overheat trip!\n");
0511                 kernel_power_off();
0512             }
0513         }
0514     } else {
0515         if (control_status & WD_REVC_WTRP)
0516             *status |= WDIOF_CARDRESET;
0517 
0518         if (control_status & WD_REVC_TTRP) {
0519             *status |= WDIOF_OVERHEAT;
0520             if (temp_panic) {
0521                 pr_info("Temperature overheat trip!\n");
0522                 kernel_power_off();
0523             }
0524         }
0525     }
0526 
0527     return 0;
0528 }
0529 
0530 static int pcwd_clear_status(void)
0531 {
0532     int control_status;
0533 
0534     if (pcwd_private.revision == PCWD_REVISION_C) {
0535         spin_lock(&pcwd_private.io_lock);
0536 
0537         if (debug >= VERBOSE)
0538             pr_info("clearing watchdog trip status\n");
0539 
0540         control_status = inb_p(pcwd_private.io_addr + 1);
0541 
0542         if (debug >= DEBUG) {
0543             pr_debug("status was: 0x%02x\n", control_status);
0544             pr_debug("sending: 0x%02x\n",
0545                  (control_status & WD_REVC_R2DS));
0546         }
0547 
0548         /* clear reset status & Keep Relay 2 disable state as it is */
0549         outb_p((control_status & WD_REVC_R2DS),
0550                         pcwd_private.io_addr + 1);
0551 
0552         spin_unlock(&pcwd_private.io_lock);
0553     }
0554     return 0;
0555 }
0556 
0557 static int pcwd_get_temperature(int *temperature)
0558 {
0559     /* check that port 0 gives temperature info and no command results */
0560     if (pcwd_private.command_mode)
0561         return -1;
0562 
0563     *temperature = 0;
0564     if (!pcwd_private.supports_temp)
0565         return -ENODEV;
0566 
0567     /*
0568      * Convert celsius to fahrenheit, since this was
0569      * the decided 'standard' for this return value.
0570      */
0571     spin_lock(&pcwd_private.io_lock);
0572     *temperature = ((inb(pcwd_private.io_addr)) * 9 / 5) + 32;
0573     spin_unlock(&pcwd_private.io_lock);
0574 
0575     if (debug >= DEBUG) {
0576         pr_debug("temperature is: %d F\n", *temperature);
0577     }
0578 
0579     return 0;
0580 }
0581 
0582 /*
0583  *  /dev/watchdog handling
0584  */
0585 
0586 static long pcwd_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
0587 {
0588     int rv;
0589     int status;
0590     int temperature;
0591     int new_heartbeat;
0592     int __user *argp = (int __user *)arg;
0593     static const struct watchdog_info ident = {
0594         .options =      WDIOF_OVERHEAT |
0595                     WDIOF_CARDRESET |
0596                     WDIOF_KEEPALIVEPING |
0597                     WDIOF_SETTIMEOUT |
0598                     WDIOF_MAGICCLOSE,
0599         .firmware_version = 1,
0600         .identity =     "PCWD",
0601     };
0602 
0603     switch (cmd) {
0604     case WDIOC_GETSUPPORT:
0605         if (copy_to_user(argp, &ident, sizeof(ident)))
0606             return -EFAULT;
0607         return 0;
0608 
0609     case WDIOC_GETSTATUS:
0610         pcwd_get_status(&status);
0611         return put_user(status, argp);
0612 
0613     case WDIOC_GETBOOTSTATUS:
0614         return put_user(pcwd_private.boot_status, argp);
0615 
0616     case WDIOC_GETTEMP:
0617         if (pcwd_get_temperature(&temperature))
0618             return -EFAULT;
0619 
0620         return put_user(temperature, argp);
0621 
0622     case WDIOC_SETOPTIONS:
0623         if (pcwd_private.revision == PCWD_REVISION_C) {
0624             if (get_user(rv, argp))
0625                 return -EFAULT;
0626 
0627             if (rv & WDIOS_DISABLECARD) {
0628                 status = pcwd_stop();
0629                 if (status < 0)
0630                     return status;
0631             }
0632             if (rv & WDIOS_ENABLECARD) {
0633                 status = pcwd_start();
0634                 if (status < 0)
0635                     return status;
0636             }
0637             if (rv & WDIOS_TEMPPANIC)
0638                 temp_panic = 1;
0639         }
0640         return -EINVAL;
0641 
0642     case WDIOC_KEEPALIVE:
0643         pcwd_keepalive();
0644         return 0;
0645 
0646     case WDIOC_SETTIMEOUT:
0647         if (get_user(new_heartbeat, argp))
0648             return -EFAULT;
0649 
0650         if (pcwd_set_heartbeat(new_heartbeat))
0651             return -EINVAL;
0652 
0653         pcwd_keepalive();
0654         fallthrough;
0655 
0656     case WDIOC_GETTIMEOUT:
0657         return put_user(heartbeat, argp);
0658 
0659     default:
0660         return -ENOTTY;
0661     }
0662 
0663     return 0;
0664 }
0665 
0666 static ssize_t pcwd_write(struct file *file, const char __user *buf, size_t len,
0667               loff_t *ppos)
0668 {
0669     if (len) {
0670         if (!nowayout) {
0671             size_t i;
0672 
0673             /* In case it was set long ago */
0674             expect_close = 0;
0675 
0676             for (i = 0; i != len; i++) {
0677                 char c;
0678 
0679                 if (get_user(c, buf + i))
0680                     return -EFAULT;
0681                 if (c == 'V')
0682                     expect_close = 42;
0683             }
0684         }
0685         pcwd_keepalive();
0686     }
0687     return len;
0688 }
0689 
0690 static int pcwd_open(struct inode *inode, struct file *file)
0691 {
0692     if (test_and_set_bit(0, &open_allowed))
0693         return -EBUSY;
0694     if (nowayout)
0695         __module_get(THIS_MODULE);
0696     /* Activate */
0697     pcwd_start();
0698     pcwd_keepalive();
0699     return stream_open(inode, file);
0700 }
0701 
0702 static int pcwd_close(struct inode *inode, struct file *file)
0703 {
0704     if (expect_close == 42)
0705         pcwd_stop();
0706     else {
0707         pr_crit("Unexpected close, not stopping watchdog!\n");
0708         pcwd_keepalive();
0709     }
0710     expect_close = 0;
0711     clear_bit(0, &open_allowed);
0712     return 0;
0713 }
0714 
0715 /*
0716  *  /dev/temperature handling
0717  */
0718 
0719 static ssize_t pcwd_temp_read(struct file *file, char __user *buf, size_t count,
0720              loff_t *ppos)
0721 {
0722     int temperature;
0723 
0724     if (pcwd_get_temperature(&temperature))
0725         return -EFAULT;
0726 
0727     if (copy_to_user(buf, &temperature, 1))
0728         return -EFAULT;
0729 
0730     return 1;
0731 }
0732 
0733 static int pcwd_temp_open(struct inode *inode, struct file *file)
0734 {
0735     if (!pcwd_private.supports_temp)
0736         return -ENODEV;
0737 
0738     return stream_open(inode, file);
0739 }
0740 
0741 static int pcwd_temp_close(struct inode *inode, struct file *file)
0742 {
0743     return 0;
0744 }
0745 
0746 /*
0747  *  Kernel Interfaces
0748  */
0749 
0750 static const struct file_operations pcwd_fops = {
0751     .owner      = THIS_MODULE,
0752     .llseek     = no_llseek,
0753     .write      = pcwd_write,
0754     .unlocked_ioctl = pcwd_ioctl,
0755     .compat_ioctl   = compat_ptr_ioctl,
0756     .open       = pcwd_open,
0757     .release    = pcwd_close,
0758 };
0759 
0760 static struct miscdevice pcwd_miscdev = {
0761     .minor =    WATCHDOG_MINOR,
0762     .name =     "watchdog",
0763     .fops =     &pcwd_fops,
0764 };
0765 
0766 static const struct file_operations pcwd_temp_fops = {
0767     .owner      = THIS_MODULE,
0768     .llseek     = no_llseek,
0769     .read       = pcwd_temp_read,
0770     .open       = pcwd_temp_open,
0771     .release    = pcwd_temp_close,
0772 };
0773 
0774 static struct miscdevice temp_miscdev = {
0775     .minor =    TEMP_MINOR,
0776     .name =     "temperature",
0777     .fops =     &pcwd_temp_fops,
0778 };
0779 
0780 /*
0781  *  Init & exit routines
0782  */
0783 
0784 static inline int get_revision(void)
0785 {
0786     int r = PCWD_REVISION_C;
0787 
0788     spin_lock(&pcwd_private.io_lock);
0789     /* REV A cards use only 2 io ports; test
0790      * presumes a floating bus reads as 0xff. */
0791     if ((inb(pcwd_private.io_addr + 2) == 0xFF) ||
0792         (inb(pcwd_private.io_addr + 3) == 0xFF))
0793         r = PCWD_REVISION_A;
0794     spin_unlock(&pcwd_private.io_lock);
0795 
0796     return r;
0797 }
0798 
0799 /*
0800  *  The ISA cards have a heartbeat bit in one of the registers, which
0801  *  register is card dependent.  The heartbeat bit is monitored, and if
0802  *  found, is considered proof that a Berkshire card has been found.
0803  *  The initial rate is once per second at board start up, then twice
0804  *  per second for normal operation.
0805  */
0806 static int pcwd_isa_match(struct device *dev, unsigned int id)
0807 {
0808     int base_addr = pcwd_ioports[id];
0809     int port0, last_port0;  /* Reg 0, in case it's REV A */
0810     int port1, last_port1;  /* Register 1 for REV C cards */
0811     int i;
0812     int retval;
0813 
0814     if (debug >= DEBUG)
0815         pr_debug("pcwd_isa_match id=%d\n", id);
0816 
0817     if (!request_region(base_addr, 4, "PCWD")) {
0818         pr_info("Port 0x%04x unavailable\n", base_addr);
0819         return 0;
0820     }
0821 
0822     retval = 0;
0823 
0824     port0 = inb_p(base_addr);   /* For REV A boards */
0825     port1 = inb_p(base_addr + 1);   /* For REV C boards */
0826     if (port0 != 0xff || port1 != 0xff) {
0827         /* Not an 'ff' from a floating bus, so must be a card! */
0828         for (i = 0; i < 4; ++i) {
0829 
0830             msleep(500);
0831 
0832             last_port0 = port0;
0833             last_port1 = port1;
0834 
0835             port0 = inb_p(base_addr);
0836             port1 = inb_p(base_addr + 1);
0837 
0838             /* Has either hearbeat bit changed?  */
0839             if ((port0 ^ last_port0) & WD_HRTBT ||
0840                 (port1 ^ last_port1) & WD_REVC_HRBT) {
0841                 retval = 1;
0842                 break;
0843             }
0844         }
0845     }
0846     release_region(base_addr, 4);
0847 
0848     return retval;
0849 }
0850 
0851 static int pcwd_isa_probe(struct device *dev, unsigned int id)
0852 {
0853     int ret;
0854 
0855     if (debug >= DEBUG)
0856         pr_debug("pcwd_isa_probe id=%d\n", id);
0857 
0858     cards_found++;
0859     if (cards_found == 1)
0860         pr_info("v%s Ken Hollis (kenji@bitgate.com)\n",
0861                             WATCHDOG_VERSION);
0862 
0863     if (cards_found > 1) {
0864         pr_err("This driver only supports 1 device\n");
0865         return -ENODEV;
0866     }
0867 
0868     if (pcwd_ioports[id] == 0x0000) {
0869         pr_err("No I/O-Address for card detected\n");
0870         return -ENODEV;
0871     }
0872     pcwd_private.io_addr = pcwd_ioports[id];
0873 
0874     spin_lock_init(&pcwd_private.io_lock);
0875 
0876     /* Check card's revision */
0877     pcwd_private.revision = get_revision();
0878 
0879     if (!request_region(pcwd_private.io_addr,
0880         (pcwd_private.revision == PCWD_REVISION_A) ? 2 : 4, "PCWD")) {
0881         pr_err("I/O address 0x%04x already in use\n",
0882                pcwd_private.io_addr);
0883         ret = -EIO;
0884         goto error_request_region;
0885     }
0886 
0887     /* Initial variables */
0888     pcwd_private.supports_temp = 0;
0889     temp_panic = 0;
0890     pcwd_private.boot_status = 0x0000;
0891 
0892     /* get the boot_status */
0893     pcwd_get_status(&pcwd_private.boot_status);
0894 
0895     /* clear the "card caused reboot" flag */
0896     pcwd_clear_status();
0897 
0898     timer_setup(&pcwd_private.timer, pcwd_timer_ping, 0);
0899 
0900     /*  Disable the board  */
0901     pcwd_stop();
0902 
0903     /*  Check whether or not the card supports the temperature device */
0904     pcwd_check_temperature_support();
0905 
0906     /* Show info about the card itself */
0907     pcwd_show_card_info();
0908 
0909     /* If heartbeat = 0 then we use the heartbeat from the dip-switches */
0910     if (heartbeat == 0)
0911         heartbeat = heartbeat_tbl[(pcwd_get_option_switches() & 0x07)];
0912 
0913     /* Check that the heartbeat value is within it's range;
0914        if not reset to the default */
0915     if (pcwd_set_heartbeat(heartbeat)) {
0916         pcwd_set_heartbeat(WATCHDOG_HEARTBEAT);
0917         pr_info("heartbeat value must be 2 <= heartbeat <= 7200, using %d\n",
0918             WATCHDOG_HEARTBEAT);
0919     }
0920 
0921     if (pcwd_private.supports_temp) {
0922         ret = misc_register(&temp_miscdev);
0923         if (ret) {
0924             pr_err("cannot register miscdev on minor=%d (err=%d)\n",
0925                    TEMP_MINOR, ret);
0926             goto error_misc_register_temp;
0927         }
0928     }
0929 
0930     ret = misc_register(&pcwd_miscdev);
0931     if (ret) {
0932         pr_err("cannot register miscdev on minor=%d (err=%d)\n",
0933                WATCHDOG_MINOR, ret);
0934         goto error_misc_register_watchdog;
0935     }
0936 
0937     pr_info("initialized. heartbeat=%d sec (nowayout=%d)\n",
0938         heartbeat, nowayout);
0939 
0940     return 0;
0941 
0942 error_misc_register_watchdog:
0943     if (pcwd_private.supports_temp)
0944         misc_deregister(&temp_miscdev);
0945 error_misc_register_temp:
0946     release_region(pcwd_private.io_addr,
0947             (pcwd_private.revision == PCWD_REVISION_A) ? 2 : 4);
0948 error_request_region:
0949     pcwd_private.io_addr = 0x0000;
0950     cards_found--;
0951     return ret;
0952 }
0953 
0954 static void pcwd_isa_remove(struct device *dev, unsigned int id)
0955 {
0956     if (debug >= DEBUG)
0957         pr_debug("pcwd_isa_remove id=%d\n", id);
0958 
0959     /*  Disable the board  */
0960     if (!nowayout)
0961         pcwd_stop();
0962 
0963     /* Deregister */
0964     misc_deregister(&pcwd_miscdev);
0965     if (pcwd_private.supports_temp)
0966         misc_deregister(&temp_miscdev);
0967     release_region(pcwd_private.io_addr,
0968             (pcwd_private.revision == PCWD_REVISION_A) ? 2 : 4);
0969     pcwd_private.io_addr = 0x0000;
0970     cards_found--;
0971 }
0972 
0973 static void pcwd_isa_shutdown(struct device *dev, unsigned int id)
0974 {
0975     if (debug >= DEBUG)
0976         pr_debug("pcwd_isa_shutdown id=%d\n", id);
0977 
0978     pcwd_stop();
0979 }
0980 
0981 static struct isa_driver pcwd_isa_driver = {
0982     .match      = pcwd_isa_match,
0983     .probe      = pcwd_isa_probe,
0984     .remove     = pcwd_isa_remove,
0985     .shutdown   = pcwd_isa_shutdown,
0986     .driver     = {
0987         .owner  = THIS_MODULE,
0988         .name   = WATCHDOG_NAME,
0989     },
0990 };
0991 
0992 module_isa_driver(pcwd_isa_driver, PCWD_ISA_NR_CARDS);
0993 
0994 MODULE_AUTHOR("Ken Hollis <kenji@bitgate.com>, "
0995         "Wim Van Sebroeck <wim@iguana.be>");
0996 MODULE_DESCRIPTION("Berkshire ISA-PC Watchdog driver");
0997 MODULE_VERSION(WATCHDOG_VERSION);
0998 MODULE_LICENSE("GPL");
[ Source navigation ] [ Diff markup ] [ Identifier search ] [ general search ]

This page was automatically generated by the 2.1.0 LXR engine.

The LXR team
Valid CSS 2.1! Valid HTML 4.01!