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