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525 lines
12 KiB
525 lines
12 KiB
// SPDX-License-Identifier: GPL-2.0-or-later |
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/* |
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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 <[email protected]> |
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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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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
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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 <linux/uaccess.h> |
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#include <linux/io.h> |
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#define WATCHDOG_VERSION "1.00" |
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#define WATCHDOG_NAME "W83977F WDT" |
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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, |
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"Watchdog timeout in seconds (15..7635), default=" |
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__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 bool nowayout = WATCHDOG_NOWAYOUT; |
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module_param(nowayout, bool, 0); |
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MODULE_PARM_DESC(nowayout, |
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"Watchdog cannot be stopped once started (default=" |
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__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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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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pr_info("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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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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pr_info("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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unsigned 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 stream_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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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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pr_crit("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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if (!nowayout) { |
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size_t ofs; |
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/* note: just in case someone wrote the |
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magic character long ago */ |
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expect_close = 0; |
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/* scan to see whether or not we got the |
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magic character */ |
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for (ofs = 0; ofs != count; ofs++) { |
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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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/* 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 const 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 long wdt_ioctl(struct file *file, 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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case WDIOC_GETSUPPORT: |
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return copy_to_user(uarg.ident, &ident, |
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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_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_KEEPALIVE: |
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wdt_keepalive(); |
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return 0; |
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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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fallthrough; |
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case WDIOC_GETTIMEOUT: |
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return put_user(timeout, uarg.i); |
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default: |
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return -ENOTTY; |
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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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.owner = THIS_MODULE, |
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.llseek = no_llseek, |
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.write = wdt_write, |
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.unlocked_ioctl = wdt_ioctl, |
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.compat_ioctl = compat_ptr_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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.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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pr_info("driver v%s\n", WATCHDOG_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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pr_info("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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pr_err("I/O address 0x%04x already in use\n", 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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pr_err("cannot register reboot notifier (err=%d)\n", rc); |
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goto err_out_region; |
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} |
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rc = misc_register(&wdt_miscdev); |
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if (rc) { |
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pr_err("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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pr_info("initialized. timeout=%d sec (nowayout=%d testmode=%d)\n", |
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timeout, nowayout, testmode); |
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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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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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module_init(w83977f_wdt_init); |
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module_exit(w83977f_wdt_exit); |
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MODULE_AUTHOR("Jose Goncalves <[email protected]>"); |
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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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