541 lines
12 KiB
C
541 lines
12 KiB
C
/*
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* W83977F Watchdog Timer Driver for Winbond W83977F I/O Chip
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*
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* (c) Copyright 2005 Jose Goncalves <jose.goncalves@inov.pt>
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*
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* Based on w83877f_wdt.c by Scott Jennings,
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* and wdt977.c by Woody Suwalski
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*
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* -----------------------
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*
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*/
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#include <linux/module.h>
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#include <linux/moduleparam.h>
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#include <linux/types.h>
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#include <linux/kernel.h>
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#include <linux/fs.h>
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#include <linux/miscdevice.h>
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#include <linux/init.h>
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#include <linux/ioport.h>
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#include <linux/watchdog.h>
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#include <linux/notifier.h>
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#include <linux/reboot.h>
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#include <asm/io.h>
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#include <asm/system.h>
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#include <asm/uaccess.h>
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#define WATCHDOG_VERSION "1.00"
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#define WATCHDOG_NAME "W83977F WDT"
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#define PFX WATCHDOG_NAME ": "
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#define DRIVER_VERSION WATCHDOG_NAME " driver, v" WATCHDOG_VERSION "\n"
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#define IO_INDEX_PORT 0x3F0
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#define IO_DATA_PORT (IO_INDEX_PORT+1)
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#define UNLOCK_DATA 0x87
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#define LOCK_DATA 0xAA
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#define DEVICE_REGISTER 0x07
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#define DEFAULT_TIMEOUT 45 /* default timeout in seconds */
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static int timeout = DEFAULT_TIMEOUT;
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static int timeoutW; /* timeout in watchdog counter units */
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static unsigned long timer_alive;
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static int testmode;
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static char expect_close;
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static DEFINE_SPINLOCK(spinlock);
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module_param(timeout, int, 0);
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MODULE_PARM_DESC(timeout,"Watchdog timeout in seconds (15..7635), default=" __MODULE_STRING(DEFAULT_TIMEOUT) ")");
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module_param(testmode, int, 0);
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MODULE_PARM_DESC(testmode,"Watchdog testmode (1 = no reboot), default=0");
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static int nowayout = WATCHDOG_NOWAYOUT;
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module_param(nowayout, int, 0);
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MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
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/*
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* Start the watchdog
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*/
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static int wdt_start(void)
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{
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unsigned long flags;
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spin_lock_irqsave(&spinlock, flags);
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/* Unlock the SuperIO chip */
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outb_p(UNLOCK_DATA,IO_INDEX_PORT);
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outb_p(UNLOCK_DATA,IO_INDEX_PORT);
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/*
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* Select device Aux2 (device=8) to set watchdog regs F2, F3 and F4.
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* F2 has the timeout in watchdog counter units.
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* F3 is set to enable watchdog LED blink at timeout.
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* F4 is used to just clear the TIMEOUT'ed state (bit 0).
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*/
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outb_p(DEVICE_REGISTER,IO_INDEX_PORT);
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outb_p(0x08,IO_DATA_PORT);
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outb_p(0xF2,IO_INDEX_PORT);
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outb_p(timeoutW,IO_DATA_PORT);
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outb_p(0xF3,IO_INDEX_PORT);
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outb_p(0x08,IO_DATA_PORT);
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outb_p(0xF4,IO_INDEX_PORT);
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outb_p(0x00,IO_DATA_PORT);
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/* Set device Aux2 active */
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outb_p(0x30,IO_INDEX_PORT);
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outb_p(0x01,IO_DATA_PORT);
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/*
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* Select device Aux1 (dev=7) to set GP16 as the watchdog output
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* (in reg E6) and GP13 as the watchdog LED output (in reg E3).
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* Map GP16 at pin 119.
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* In test mode watch the bit 0 on F4 to indicate "triggered" or
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* check watchdog LED on SBC.
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*/
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outb_p(DEVICE_REGISTER,IO_INDEX_PORT);
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outb_p(0x07,IO_DATA_PORT);
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if (!testmode)
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{
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unsigned pin_map;
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outb_p(0xE6,IO_INDEX_PORT);
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outb_p(0x0A,IO_DATA_PORT);
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outb_p(0x2C,IO_INDEX_PORT);
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pin_map = inb_p(IO_DATA_PORT);
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pin_map |= 0x10;
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pin_map &= ~(0x20);
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outb_p(0x2C,IO_INDEX_PORT);
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outb_p(pin_map,IO_DATA_PORT);
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}
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outb_p(0xE3,IO_INDEX_PORT);
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outb_p(0x08,IO_DATA_PORT);
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/* Set device Aux1 active */
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outb_p(0x30,IO_INDEX_PORT);
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outb_p(0x01,IO_DATA_PORT);
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/* Lock the SuperIO chip */
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outb_p(LOCK_DATA,IO_INDEX_PORT);
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spin_unlock_irqrestore(&spinlock, flags);
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printk(KERN_INFO PFX "activated.\n");
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return 0;
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}
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/*
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* Stop the watchdog
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*/
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static int wdt_stop(void)
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{
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unsigned long flags;
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spin_lock_irqsave(&spinlock, flags);
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/* Unlock the SuperIO chip */
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outb_p(UNLOCK_DATA,IO_INDEX_PORT);
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outb_p(UNLOCK_DATA,IO_INDEX_PORT);
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/*
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* Select device Aux2 (device=8) to set watchdog regs F2, F3 and F4.
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* F2 is reset to its default value (watchdog timer disabled).
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* F3 is reset to its default state.
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* F4 clears the TIMEOUT'ed state (bit 0) - back to default.
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*/
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outb_p(DEVICE_REGISTER,IO_INDEX_PORT);
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outb_p(0x08,IO_DATA_PORT);
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outb_p(0xF2,IO_INDEX_PORT);
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outb_p(0xFF,IO_DATA_PORT);
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outb_p(0xF3,IO_INDEX_PORT);
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outb_p(0x00,IO_DATA_PORT);
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outb_p(0xF4,IO_INDEX_PORT);
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outb_p(0x00,IO_DATA_PORT);
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outb_p(0xF2,IO_INDEX_PORT);
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outb_p(0x00,IO_DATA_PORT);
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/*
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* Select device Aux1 (dev=7) to set GP16 (in reg E6) and
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* Gp13 (in reg E3) as inputs.
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*/
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outb_p(DEVICE_REGISTER,IO_INDEX_PORT);
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outb_p(0x07,IO_DATA_PORT);
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if (!testmode)
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{
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outb_p(0xE6,IO_INDEX_PORT);
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outb_p(0x01,IO_DATA_PORT);
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}
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outb_p(0xE3,IO_INDEX_PORT);
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outb_p(0x01,IO_DATA_PORT);
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/* Lock the SuperIO chip */
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outb_p(LOCK_DATA,IO_INDEX_PORT);
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spin_unlock_irqrestore(&spinlock, flags);
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printk(KERN_INFO PFX "shutdown.\n");
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return 0;
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}
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/*
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* Send a keepalive ping to the watchdog
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* This is done by simply re-writing the timeout to reg. 0xF2
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*/
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static int wdt_keepalive(void)
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{
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unsigned long flags;
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spin_lock_irqsave(&spinlock, flags);
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/* Unlock the SuperIO chip */
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outb_p(UNLOCK_DATA,IO_INDEX_PORT);
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outb_p(UNLOCK_DATA,IO_INDEX_PORT);
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/* Select device Aux2 (device=8) to kick watchdog reg F2 */
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outb_p(DEVICE_REGISTER,IO_INDEX_PORT);
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outb_p(0x08,IO_DATA_PORT);
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outb_p(0xF2,IO_INDEX_PORT);
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outb_p(timeoutW,IO_DATA_PORT);
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/* Lock the SuperIO chip */
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outb_p(LOCK_DATA,IO_INDEX_PORT);
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spin_unlock_irqrestore(&spinlock, flags);
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return 0;
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}
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/*
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* Set the watchdog timeout value
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*/
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static int wdt_set_timeout(int t)
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{
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int tmrval;
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/*
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* Convert seconds to watchdog counter time units, rounding up.
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* On PCM-5335 watchdog units are 30 seconds/step with 15 sec startup
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* value. This information is supplied in the PCM-5335 manual and was
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* checked by me on a real board. This is a bit strange because W83977f
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* datasheet says counter unit is in minutes!
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*/
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if (t < 15)
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return -EINVAL;
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tmrval = ((t + 15) + 29) / 30;
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if (tmrval > 255)
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return -EINVAL;
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/*
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* timeout is the timeout in seconds,
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* timeoutW is the timeout in watchdog counter units.
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*/
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timeoutW = tmrval;
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timeout = (timeoutW * 30) - 15;
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return 0;
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}
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/*
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* Get the watchdog status
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*/
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static int wdt_get_status(int *status)
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{
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int new_status;
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unsigned long flags;
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spin_lock_irqsave(&spinlock, flags);
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/* Unlock the SuperIO chip */
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outb_p(UNLOCK_DATA,IO_INDEX_PORT);
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outb_p(UNLOCK_DATA,IO_INDEX_PORT);
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/* Select device Aux2 (device=8) to read watchdog reg F4 */
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outb_p(DEVICE_REGISTER,IO_INDEX_PORT);
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outb_p(0x08,IO_DATA_PORT);
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outb_p(0xF4,IO_INDEX_PORT);
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new_status = inb_p(IO_DATA_PORT);
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/* Lock the SuperIO chip */
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outb_p(LOCK_DATA,IO_INDEX_PORT);
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spin_unlock_irqrestore(&spinlock, flags);
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*status = 0;
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if (new_status & 1)
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*status |= WDIOF_CARDRESET;
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return 0;
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}
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/*
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* /dev/watchdog handling
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*/
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static int wdt_open(struct inode *inode, struct file *file)
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{
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/* If the watchdog is alive we don't need to start it again */
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if( test_and_set_bit(0, &timer_alive) )
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return -EBUSY;
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if (nowayout)
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__module_get(THIS_MODULE);
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wdt_start();
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return nonseekable_open(inode, file);
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}
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static int wdt_release(struct inode *inode, struct file *file)
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{
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/*
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* Shut off the timer.
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* Lock it in if it's a module and we set nowayout
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*/
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if (expect_close == 42)
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{
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wdt_stop();
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clear_bit(0, &timer_alive);
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} else {
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wdt_keepalive();
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printk(KERN_CRIT PFX "unexpected close, not stopping watchdog!\n");
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}
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expect_close = 0;
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return 0;
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}
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/*
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* wdt_write:
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* @file: file handle to the watchdog
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* @buf: buffer to write (unused as data does not matter here
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* @count: count of bytes
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* @ppos: pointer to the position to write. No seeks allowed
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*
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* A write to a watchdog device is defined as a keepalive signal. Any
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* write of data will do, as we we don't define content meaning.
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*/
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static ssize_t wdt_write(struct file *file, const char __user *buf,
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size_t count, loff_t *ppos)
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{
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/* See if we got the magic character 'V' and reload the timer */
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if(count)
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{
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if (!nowayout)
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{
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size_t ofs;
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/* note: just in case someone wrote the magic character long ago */
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expect_close = 0;
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/* scan to see whether or not we got the magic character */
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for(ofs = 0; ofs != count; ofs++)
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{
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char c;
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if (get_user(c, buf + ofs))
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return -EFAULT;
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if (c == 'V') {
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expect_close = 42;
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}
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}
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}
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/* someone wrote to us, we should restart timer */
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wdt_keepalive();
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}
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return count;
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}
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/*
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* wdt_ioctl:
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* @inode: inode of the device
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* @file: file handle to the device
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* @cmd: watchdog command
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* @arg: argument pointer
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*
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* The watchdog API defines a common set of functions for all watchdogs
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* according to their available features.
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*/
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static struct watchdog_info ident = {
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.options = WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING,
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.firmware_version = 1,
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.identity = WATCHDOG_NAME,
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};
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static int wdt_ioctl(struct inode *inode, struct file *file,
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unsigned int cmd, unsigned long arg)
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{
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int status;
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int new_options, retval = -EINVAL;
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int new_timeout;
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union {
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struct watchdog_info __user *ident;
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int __user *i;
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} uarg;
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uarg.i = (int __user *)arg;
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switch(cmd)
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{
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default:
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return -ENOTTY;
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case WDIOC_GETSUPPORT:
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return copy_to_user(uarg.ident, &ident, sizeof(ident)) ? -EFAULT : 0;
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case WDIOC_GETSTATUS:
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wdt_get_status(&status);
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return put_user(status, uarg.i);
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case WDIOC_GETBOOTSTATUS:
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return put_user(0, uarg.i);
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case WDIOC_KEEPALIVE:
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wdt_keepalive();
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return 0;
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case WDIOC_SETOPTIONS:
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if (get_user (new_options, uarg.i))
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return -EFAULT;
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if (new_options & WDIOS_DISABLECARD) {
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wdt_stop();
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retval = 0;
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}
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if (new_options & WDIOS_ENABLECARD) {
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wdt_start();
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retval = 0;
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}
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return retval;
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case WDIOC_SETTIMEOUT:
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if (get_user(new_timeout, uarg.i))
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return -EFAULT;
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if (wdt_set_timeout(new_timeout))
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return -EINVAL;
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wdt_keepalive();
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/* Fall */
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case WDIOC_GETTIMEOUT:
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return put_user(timeout, uarg.i);
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}
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}
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static int wdt_notify_sys(struct notifier_block *this, unsigned long code,
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void *unused)
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{
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if (code==SYS_DOWN || code==SYS_HALT)
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wdt_stop();
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return NOTIFY_DONE;
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}
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static const struct file_operations wdt_fops=
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{
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.owner = THIS_MODULE,
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.llseek = no_llseek,
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.write = wdt_write,
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.ioctl = wdt_ioctl,
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.open = wdt_open,
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.release = wdt_release,
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};
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static struct miscdevice wdt_miscdev=
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{
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.minor = WATCHDOG_MINOR,
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.name = "watchdog",
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.fops = &wdt_fops,
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};
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static struct notifier_block wdt_notifier = {
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.notifier_call = wdt_notify_sys,
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};
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static int __init w83977f_wdt_init(void)
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{
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int rc;
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printk(KERN_INFO PFX DRIVER_VERSION);
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/*
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* Check that the timeout value is within it's range ;
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* if not reset to the default
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*/
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if (wdt_set_timeout(timeout)) {
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wdt_set_timeout(DEFAULT_TIMEOUT);
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printk(KERN_INFO PFX "timeout value must be 15<=timeout<=7635, using %d\n",
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DEFAULT_TIMEOUT);
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}
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if (!request_region(IO_INDEX_PORT, 2, WATCHDOG_NAME))
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{
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printk(KERN_ERR PFX "I/O address 0x%04x already in use\n",
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IO_INDEX_PORT);
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rc = -EIO;
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goto err_out;
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}
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rc = register_reboot_notifier(&wdt_notifier);
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if (rc)
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{
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printk(KERN_ERR PFX "cannot register reboot notifier (err=%d)\n",
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rc);
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goto err_out_region;
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}
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|
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rc = misc_register(&wdt_miscdev);
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if (rc)
|
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{
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printk(KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n",
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wdt_miscdev.minor, rc);
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goto err_out_reboot;
|
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}
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|
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printk(KERN_INFO PFX "initialized. timeout=%d sec (nowayout=%d testmode=%d)\n",
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timeout, nowayout, testmode);
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|
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return 0;
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err_out_reboot:
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unregister_reboot_notifier(&wdt_notifier);
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err_out_region:
|
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release_region(IO_INDEX_PORT,2);
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err_out:
|
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return rc;
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}
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|
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static void __exit w83977f_wdt_exit(void)
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{
|
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wdt_stop();
|
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misc_deregister(&wdt_miscdev);
|
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unregister_reboot_notifier(&wdt_notifier);
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release_region(IO_INDEX_PORT,2);
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}
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|
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module_init(w83977f_wdt_init);
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module_exit(w83977f_wdt_exit);
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|
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MODULE_AUTHOR("Jose Goncalves <jose.goncalves@inov.pt>");
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MODULE_DESCRIPTION("Driver for watchdog timer in W83977F I/O chip");
|
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MODULE_LICENSE("GPL");
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MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
|