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Sven Anders & Marcus Junker789fc0a2006-08-24 17:11:50 +02001/*
2 * NS pc87413-wdt Watchdog Timer driver for Linux 2.6.x.x
3 *
Sven Anders & Marcus Junker00b3b3e2006-10-16 18:18:09 +02004 * This code is based on wdt.c with original copyright.
Sven Anders & Marcus Junker789fc0a2006-08-24 17:11:50 +02005 *
Sven Anders & Marcus Junker00b3b3e2006-10-16 18:18:09 +02006 * (C) Copyright 2006 Sven Anders, <anders@anduras.de>
7 * and Marcus Junker, <junker@anduras.de>
Sven Anders & Marcus Junker789fc0a2006-08-24 17:11:50 +02008 *
9 * This program is free software; you can redistribute it and/or
10 * modify it under the terms of the GNU General Public License
11 * as published by the Free Software Foundation; either version
12 * 2 of the License, or (at your option) any later version.
13 *
Sven Anders & Marcus Junker00b3b3e2006-10-16 18:18:09 +020014 * Neither Sven Anders, Marcus Junker nor ANDURAS AG
Sven Anders & Marcus Junker789fc0a2006-08-24 17:11:50 +020015 * admit liability nor provide warranty for any of this software.
16 * This material is provided "AS-IS" and at no charge.
17 *
Sven Anders & Marcus Junker00b3b3e2006-10-16 18:18:09 +020018 * Release 1.1
Sven Anders & Marcus Junker789fc0a2006-08-24 17:11:50 +020019 */
20
Joe Perches27c766a2012-02-15 15:06:19 -080021#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
22
Sven Anders & Marcus Junker789fc0a2006-08-24 17:11:50 +020023#include <linux/module.h>
24#include <linux/types.h>
25#include <linux/miscdevice.h>
26#include <linux/watchdog.h>
27#include <linux/ioport.h>
28#include <linux/delay.h>
29#include <linux/notifier.h>
30#include <linux/fs.h>
31#include <linux/reboot.h>
32#include <linux/init.h>
33#include <linux/spinlock.h>
34#include <linux/moduleparam.h>
Alan Coxaee334c2008-05-19 14:07:37 +010035#include <linux/io.h>
36#include <linux/uaccess.h>
Sven Anders & Marcus Junker789fc0a2006-08-24 17:11:50 +020037
Sven Anders & Marcus Junker789fc0a2006-08-24 17:11:50 +020038
Sven Anders & Marcus Junker00b3b3e2006-10-16 18:18:09 +020039/* #define DEBUG 1 */
Sven Anders & Marcus Junker789fc0a2006-08-24 17:11:50 +020040
Wim Van Sebroeck7944d3a2008-08-06 20:19:41 +000041#define DEFAULT_TIMEOUT 1 /* 1 minute */
Sven Anders & Marcus Junker00b3b3e2006-10-16 18:18:09 +020042#define MAX_TIMEOUT 255
43
44#define VERSION "1.1"
45#define MODNAME "pc87413 WDT"
Sven Anders & Marcus Junker00b3b3e2006-10-16 18:18:09 +020046#define DPFX MODNAME " - DEBUG: "
47
Wim Van Sebroeck7944d3a2008-08-06 20:19:41 +000048#define WDT_INDEX_IO_PORT (io+0) /* I/O port base (index register) */
Sven Anders & Marcus Junker789fc0a2006-08-24 17:11:50 +020049#define WDT_DATA_IO_PORT (WDT_INDEX_IO_PORT+1)
Sven Anders & Marcus Junker00b3b3e2006-10-16 18:18:09 +020050#define SWC_LDN 0x04
Wim Van Sebroeck7944d3a2008-08-06 20:19:41 +000051#define SIOCFG2 0x22 /* Serial IO register */
Lucas De Marchi25985ed2011-03-30 22:57:33 -030052#define WDCTL 0x10 /* Watchdog-Timer-Control-Register */
Wim Van Sebroeck7944d3a2008-08-06 20:19:41 +000053#define WDTO 0x11 /* Watchdog timeout register */
54#define WDCFG 0x12 /* Watchdog config register */
Sven Anders & Marcus Junker789fc0a2006-08-24 17:11:50 +020055
Randy Dunlap76550d32010-05-01 09:46:15 -070056#define IO_DEFAULT 0x2E /* Address used on Portwell Boards */
57
58static int io = IO_DEFAULT;
Jonathan McDowell7ccdb942011-04-14 12:02:39 -070059static int swc_base_addr = -1;
Sven Anders & Marcus Junker789fc0a2006-08-24 17:11:50 +020060
Wim Van Sebroeck7944d3a2008-08-06 20:19:41 +000061static int timeout = DEFAULT_TIMEOUT; /* timeout value */
Alan Coxaee334c2008-05-19 14:07:37 +010062static unsigned long timer_enabled; /* is the timer enabled? */
Sven Anders & Marcus Junker789fc0a2006-08-24 17:11:50 +020063
Alan Coxaee334c2008-05-19 14:07:37 +010064static char expect_close; /* is the close expected? */
Sven Anders & Marcus Junker789fc0a2006-08-24 17:11:50 +020065
Alan Coxaee334c2008-05-19 14:07:37 +010066static DEFINE_SPINLOCK(io_lock); /* to guard us from io races */
Sven Anders & Marcus Junker789fc0a2006-08-24 17:11:50 +020067
Wim Van Sebroeck86a1e182012-03-05 16:51:11 +010068static bool nowayout = WATCHDOG_NOWAYOUT;
Sven Anders & Marcus Junker789fc0a2006-08-24 17:11:50 +020069
Sven Anders & Marcus Junker00b3b3e2006-10-16 18:18:09 +020070/* -- Low level function ----------------------------------------*/
Sven Anders & Marcus Junker789fc0a2006-08-24 17:11:50 +020071
Sven Anders & Marcus Junker00b3b3e2006-10-16 18:18:09 +020072/* Select pins for Watchdog output */
Sven Anders & Marcus Junker789fc0a2006-08-24 17:11:50 +020073
Alan Coxaee334c2008-05-19 14:07:37 +010074static inline void pc87413_select_wdt_out(void)
Sven Anders & Marcus Junker789fc0a2006-08-24 17:11:50 +020075{
Sven Anders & Marcus Junker00b3b3e2006-10-16 18:18:09 +020076 unsigned int cr_data = 0;
Sven Anders & Marcus Junker789fc0a2006-08-24 17:11:50 +020077
Sven Anders & Marcus Junker00b3b3e2006-10-16 18:18:09 +020078 /* Step 1: Select multiple pin,pin55,as WDT output */
Sven Anders & Marcus Junker789fc0a2006-08-24 17:11:50 +020079
80 outb_p(SIOCFG2, WDT_INDEX_IO_PORT);
81
Alan Coxaee334c2008-05-19 14:07:37 +010082 cr_data = inb(WDT_DATA_IO_PORT);
Sven Anders & Marcus Junker789fc0a2006-08-24 17:11:50 +020083
84 cr_data |= 0x80; /* Set Bit7 to 1*/
85 outb_p(SIOCFG2, WDT_INDEX_IO_PORT);
86
87 outb_p(cr_data, WDT_DATA_IO_PORT);
88
Sven Anders & Marcus Junker00b3b3e2006-10-16 18:18:09 +020089#ifdef DEBUG
Joe Perches27c766a2012-02-15 15:06:19 -080090 pr_info(DPFX
Alan Coxaee334c2008-05-19 14:07:37 +010091 "Select multiple pin,pin55,as WDT output: Bit7 to 1: %d\n",
92 cr_data);
Sven Anders & Marcus Junker00b3b3e2006-10-16 18:18:09 +020093#endif
Sven Anders & Marcus Junker789fc0a2006-08-24 17:11:50 +020094}
95
Sven Anders & Marcus Junker00b3b3e2006-10-16 18:18:09 +020096/* Enable SWC functions */
Sven Anders & Marcus Junker789fc0a2006-08-24 17:11:50 +020097
Sven Anders & Marcus Junker00b3b3e2006-10-16 18:18:09 +020098static inline void pc87413_enable_swc(void)
99{
Alan Coxaee334c2008-05-19 14:07:37 +0100100 unsigned int cr_data = 0;
Sven Anders & Marcus Junker789fc0a2006-08-24 17:11:50 +0200101
102 /* Step 2: Enable SWC functions */
103
Wim Van Sebroeck7944d3a2008-08-06 20:19:41 +0000104 outb_p(0x07, WDT_INDEX_IO_PORT); /* Point SWC_LDN (LDN=4) */
Sven Anders & Marcus Junker789fc0a2006-08-24 17:11:50 +0200105 outb_p(SWC_LDN, WDT_DATA_IO_PORT);
106
Wim Van Sebroeck7944d3a2008-08-06 20:19:41 +0000107 outb_p(0x30, WDT_INDEX_IO_PORT); /* Read Index 0x30 First */
Sven Anders & Marcus Junker00b3b3e2006-10-16 18:18:09 +0200108 cr_data = inb(WDT_DATA_IO_PORT);
Wim Van Sebroeck7944d3a2008-08-06 20:19:41 +0000109 cr_data |= 0x01; /* Set Bit0 to 1 */
Sven Anders & Marcus Junker789fc0a2006-08-24 17:11:50 +0200110 outb_p(0x30, WDT_INDEX_IO_PORT);
Wim Van Sebroeck7944d3a2008-08-06 20:19:41 +0000111 outb_p(cr_data, WDT_DATA_IO_PORT); /* Index0x30_bit0P1 */
Sven Anders & Marcus Junker789fc0a2006-08-24 17:11:50 +0200112
Sven Anders & Marcus Junker00b3b3e2006-10-16 18:18:09 +0200113#ifdef DEBUG
Joe Perches27c766a2012-02-15 15:06:19 -0800114 pr_info(DPFX "pc87413 - Enable SWC functions\n");
Sven Anders & Marcus Junker00b3b3e2006-10-16 18:18:09 +0200115#endif
Sven Anders & Marcus Junker789fc0a2006-08-24 17:11:50 +0200116}
117
Sven Anders & Marcus Junker00b3b3e2006-10-16 18:18:09 +0200118/* Read SWC I/O base address */
119
Jonathan McDowell7ccdb942011-04-14 12:02:39 -0700120static void pc87413_get_swc_base_addr(void)
Sven Anders & Marcus Junker789fc0a2006-08-24 17:11:50 +0200121{
Sven Anders & Marcus Junker00b3b3e2006-10-16 18:18:09 +0200122 unsigned char addr_l, addr_h = 0;
Sven Anders & Marcus Junker789fc0a2006-08-24 17:11:50 +0200123
124 /* Step 3: Read SWC I/O Base Address */
125
Wim Van Sebroeck7944d3a2008-08-06 20:19:41 +0000126 outb_p(0x60, WDT_INDEX_IO_PORT); /* Read Index 0x60 */
Sven Anders & Marcus Junker00b3b3e2006-10-16 18:18:09 +0200127 addr_h = inb(WDT_DATA_IO_PORT);
Sven Anders & Marcus Junker789fc0a2006-08-24 17:11:50 +0200128
Wim Van Sebroeck7944d3a2008-08-06 20:19:41 +0000129 outb_p(0x61, WDT_INDEX_IO_PORT); /* Read Index 0x61 */
Sven Anders & Marcus Junker789fc0a2006-08-24 17:11:50 +0200130
Sven Anders & Marcus Junker00b3b3e2006-10-16 18:18:09 +0200131 addr_l = inb(WDT_DATA_IO_PORT);
Sven Anders & Marcus Junker789fc0a2006-08-24 17:11:50 +0200132
133 swc_base_addr = (addr_h << 8) + addr_l;
Sven Anders & Marcus Junker00b3b3e2006-10-16 18:18:09 +0200134#ifdef DEBUG
Joe Perches27c766a2012-02-15 15:06:19 -0800135 pr_info(DPFX
Alan Coxaee334c2008-05-19 14:07:37 +0100136 "Read SWC I/O Base Address: low %d, high %d, res %d\n",
137 addr_l, addr_h, swc_base_addr);
Sven Anders & Marcus Junker00b3b3e2006-10-16 18:18:09 +0200138#endif
Sven Anders & Marcus Junker789fc0a2006-08-24 17:11:50 +0200139}
140
Sven Anders & Marcus Junker00b3b3e2006-10-16 18:18:09 +0200141/* Select Bank 3 of SWC */
142
Jonathan McDowell7ccdb942011-04-14 12:02:39 -0700143static inline void pc87413_swc_bank3(void)
Sven Anders & Marcus Junker789fc0a2006-08-24 17:11:50 +0200144{
145 /* Step 4: Select Bank3 of SWC */
Sven Anders & Marcus Junker00b3b3e2006-10-16 18:18:09 +0200146 outb_p(inb(swc_base_addr + 0x0f) | 0x03, swc_base_addr + 0x0f);
Sven Anders & Marcus Junker00b3b3e2006-10-16 18:18:09 +0200147#ifdef DEBUG
Joe Perches27c766a2012-02-15 15:06:19 -0800148 pr_info(DPFX "Select Bank3 of SWC\n");
Sven Anders & Marcus Junker00b3b3e2006-10-16 18:18:09 +0200149#endif
Sven Anders & Marcus Junker789fc0a2006-08-24 17:11:50 +0200150}
151
Sven Anders & Marcus Junker00b3b3e2006-10-16 18:18:09 +0200152/* Set watchdog timeout to x minutes */
153
Jonathan McDowell7ccdb942011-04-14 12:02:39 -0700154static inline void pc87413_programm_wdto(char pc87413_time)
Sven Anders & Marcus Junker789fc0a2006-08-24 17:11:50 +0200155{
156 /* Step 5: Programm WDTO, Twd. */
Sven Anders & Marcus Junker00b3b3e2006-10-16 18:18:09 +0200157 outb_p(pc87413_time, swc_base_addr + WDTO);
Sven Anders & Marcus Junker00b3b3e2006-10-16 18:18:09 +0200158#ifdef DEBUG
Joe Perches27c766a2012-02-15 15:06:19 -0800159 pr_info(DPFX "Set WDTO to %d minutes\n", pc87413_time);
Sven Anders & Marcus Junker00b3b3e2006-10-16 18:18:09 +0200160#endif
Sven Anders & Marcus Junker789fc0a2006-08-24 17:11:50 +0200161}
162
Sven Anders & Marcus Junker00b3b3e2006-10-16 18:18:09 +0200163/* Enable WDEN */
164
Jonathan McDowell7ccdb942011-04-14 12:02:39 -0700165static inline void pc87413_enable_wden(void)
Sven Anders & Marcus Junker789fc0a2006-08-24 17:11:50 +0200166{
167 /* Step 6: Enable WDEN */
Alan Coxaee334c2008-05-19 14:07:37 +0100168 outb_p(inb(swc_base_addr + WDCTL) | 0x01, swc_base_addr + WDCTL);
Sven Anders & Marcus Junker00b3b3e2006-10-16 18:18:09 +0200169#ifdef DEBUG
Joe Perches27c766a2012-02-15 15:06:19 -0800170 pr_info(DPFX "Enable WDEN\n");
Sven Anders & Marcus Junker00b3b3e2006-10-16 18:18:09 +0200171#endif
Sven Anders & Marcus Junker789fc0a2006-08-24 17:11:50 +0200172}
173
Sven Anders & Marcus Junker00b3b3e2006-10-16 18:18:09 +0200174/* Enable SW_WD_TREN */
Jonathan McDowell7ccdb942011-04-14 12:02:39 -0700175static inline void pc87413_enable_sw_wd_tren(void)
Sven Anders & Marcus Junker789fc0a2006-08-24 17:11:50 +0200176{
177 /* Enable SW_WD_TREN */
Alan Coxaee334c2008-05-19 14:07:37 +0100178 outb_p(inb(swc_base_addr + WDCFG) | 0x80, swc_base_addr + WDCFG);
Sven Anders & Marcus Junker00b3b3e2006-10-16 18:18:09 +0200179#ifdef DEBUG
Joe Perches27c766a2012-02-15 15:06:19 -0800180 pr_info(DPFX "Enable SW_WD_TREN\n");
Sven Anders & Marcus Junker00b3b3e2006-10-16 18:18:09 +0200181#endif
Sven Anders & Marcus Junker789fc0a2006-08-24 17:11:50 +0200182}
183
Sven Anders & Marcus Junker00b3b3e2006-10-16 18:18:09 +0200184/* Disable SW_WD_TREN */
185
Jonathan McDowell7ccdb942011-04-14 12:02:39 -0700186static inline void pc87413_disable_sw_wd_tren(void)
Sven Anders & Marcus Junker789fc0a2006-08-24 17:11:50 +0200187{
188 /* Disable SW_WD_TREN */
Alan Coxaee334c2008-05-19 14:07:37 +0100189 outb_p(inb(swc_base_addr + WDCFG) & 0x7f, swc_base_addr + WDCFG);
Sven Anders & Marcus Junker00b3b3e2006-10-16 18:18:09 +0200190#ifdef DEBUG
Joe Perches27c766a2012-02-15 15:06:19 -0800191 pr_info(DPFX "pc87413 - Disable SW_WD_TREN\n");
Sven Anders & Marcus Junker00b3b3e2006-10-16 18:18:09 +0200192#endif
Sven Anders & Marcus Junker789fc0a2006-08-24 17:11:50 +0200193}
194
Sven Anders & Marcus Junker00b3b3e2006-10-16 18:18:09 +0200195/* Enable SW_WD_TRG */
Sven Anders & Marcus Junker789fc0a2006-08-24 17:11:50 +0200196
Jonathan McDowell7ccdb942011-04-14 12:02:39 -0700197static inline void pc87413_enable_sw_wd_trg(void)
Sven Anders & Marcus Junker789fc0a2006-08-24 17:11:50 +0200198{
Sven Anders & Marcus Junker789fc0a2006-08-24 17:11:50 +0200199 /* Enable SW_WD_TRG */
Alan Coxaee334c2008-05-19 14:07:37 +0100200 outb_p(inb(swc_base_addr + WDCTL) | 0x80, swc_base_addr + WDCTL);
Sven Anders & Marcus Junker00b3b3e2006-10-16 18:18:09 +0200201#ifdef DEBUG
Joe Perches27c766a2012-02-15 15:06:19 -0800202 pr_info(DPFX "pc87413 - Enable SW_WD_TRG\n");
Sven Anders & Marcus Junker00b3b3e2006-10-16 18:18:09 +0200203#endif
Sven Anders & Marcus Junker789fc0a2006-08-24 17:11:50 +0200204}
205
Sven Anders & Marcus Junker00b3b3e2006-10-16 18:18:09 +0200206/* Disable SW_WD_TRG */
Sven Anders & Marcus Junker789fc0a2006-08-24 17:11:50 +0200207
Jonathan McDowell7ccdb942011-04-14 12:02:39 -0700208static inline void pc87413_disable_sw_wd_trg(void)
Sven Anders & Marcus Junker00b3b3e2006-10-16 18:18:09 +0200209{
Sven Anders & Marcus Junker789fc0a2006-08-24 17:11:50 +0200210 /* Disable SW_WD_TRG */
Alan Coxaee334c2008-05-19 14:07:37 +0100211 outb_p(inb(swc_base_addr + WDCTL) & 0x7f, swc_base_addr + WDCTL);
Sven Anders & Marcus Junker00b3b3e2006-10-16 18:18:09 +0200212#ifdef DEBUG
Joe Perches27c766a2012-02-15 15:06:19 -0800213 pr_info(DPFX "Disable SW_WD_TRG\n");
Sven Anders & Marcus Junker00b3b3e2006-10-16 18:18:09 +0200214#endif
Sven Anders & Marcus Junker789fc0a2006-08-24 17:11:50 +0200215}
216
Sven Anders & Marcus Junker00b3b3e2006-10-16 18:18:09 +0200217/* -- Higher level functions ------------------------------------*/
Sven Anders & Marcus Junker789fc0a2006-08-24 17:11:50 +0200218
Sven Anders & Marcus Junker00b3b3e2006-10-16 18:18:09 +0200219/* Enable the watchdog */
Sven Anders & Marcus Junker789fc0a2006-08-24 17:11:50 +0200220
Sven Anders & Marcus Junker00b3b3e2006-10-16 18:18:09 +0200221static void pc87413_enable(void)
Sven Anders & Marcus Junker789fc0a2006-08-24 17:11:50 +0200222{
Sven Anders & Marcus Junker00b3b3e2006-10-16 18:18:09 +0200223 spin_lock(&io_lock);
224
Jonathan McDowell7ccdb942011-04-14 12:02:39 -0700225 pc87413_swc_bank3();
226 pc87413_programm_wdto(timeout);
227 pc87413_enable_wden();
228 pc87413_enable_sw_wd_tren();
229 pc87413_enable_sw_wd_trg();
Sven Anders & Marcus Junker00b3b3e2006-10-16 18:18:09 +0200230
231 spin_unlock(&io_lock);
232}
233
234/* Disable the watchdog */
235
236static void pc87413_disable(void)
237{
Sven Anders & Marcus Junker00b3b3e2006-10-16 18:18:09 +0200238 spin_lock(&io_lock);
Sven Anders & Marcus Junker789fc0a2006-08-24 17:11:50 +0200239
Jonathan McDowell7ccdb942011-04-14 12:02:39 -0700240 pc87413_swc_bank3();
241 pc87413_disable_sw_wd_tren();
242 pc87413_disable_sw_wd_trg();
243 pc87413_programm_wdto(0);
Sven Anders & Marcus Junker00b3b3e2006-10-16 18:18:09 +0200244
245 spin_unlock(&io_lock);
Sven Anders & Marcus Junker789fc0a2006-08-24 17:11:50 +0200246}
247
Sven Anders & Marcus Junker00b3b3e2006-10-16 18:18:09 +0200248/* Refresh the watchdog */
Sven Anders & Marcus Junker789fc0a2006-08-24 17:11:50 +0200249
Sven Anders & Marcus Junker00b3b3e2006-10-16 18:18:09 +0200250static void pc87413_refresh(void)
Sven Anders & Marcus Junker789fc0a2006-08-24 17:11:50 +0200251{
Sven Anders & Marcus Junker00b3b3e2006-10-16 18:18:09 +0200252 spin_lock(&io_lock);
Sven Anders & Marcus Junker789fc0a2006-08-24 17:11:50 +0200253
Jonathan McDowell7ccdb942011-04-14 12:02:39 -0700254 pc87413_swc_bank3();
255 pc87413_disable_sw_wd_tren();
256 pc87413_disable_sw_wd_trg();
257 pc87413_programm_wdto(timeout);
258 pc87413_enable_wden();
259 pc87413_enable_sw_wd_tren();
260 pc87413_enable_sw_wd_trg();
Sven Anders & Marcus Junker00b3b3e2006-10-16 18:18:09 +0200261
262 spin_unlock(&io_lock);
Sven Anders & Marcus Junker789fc0a2006-08-24 17:11:50 +0200263}
264
Sven Anders & Marcus Junker00b3b3e2006-10-16 18:18:09 +0200265/* -- File operations -------------------------------------------*/
Sven Anders & Marcus Junker789fc0a2006-08-24 17:11:50 +0200266
Sven Anders & Marcus Junker00b3b3e2006-10-16 18:18:09 +0200267/**
268 * pc87413_open:
269 * @inode: inode of device
270 * @file: file handle to device
271 *
272 */
273
274static int pc87413_open(struct inode *inode, struct file *file)
Sven Anders & Marcus Junker789fc0a2006-08-24 17:11:50 +0200275{
Sven Anders & Marcus Junker00b3b3e2006-10-16 18:18:09 +0200276 /* /dev/watchdog can only be opened once */
Sven Anders & Marcus Junker789fc0a2006-08-24 17:11:50 +0200277
Sven Anders & Marcus Junker00b3b3e2006-10-16 18:18:09 +0200278 if (test_and_set_bit(0, &timer_enabled))
279 return -EBUSY;
Sven Anders & Marcus Junker789fc0a2006-08-24 17:11:50 +0200280
Sven Anders & Marcus Junker00b3b3e2006-10-16 18:18:09 +0200281 if (nowayout)
282 __module_get(THIS_MODULE);
283
284 /* Reload and activate timer */
285 pc87413_refresh();
286
Joe Perches27c766a2012-02-15 15:06:19 -0800287 pr_info("Watchdog enabled. Timeout set to %d minute(s).\n", timeout);
Sven Anders & Marcus Junker00b3b3e2006-10-16 18:18:09 +0200288
289 return nonseekable_open(inode, file);
Sven Anders & Marcus Junker789fc0a2006-08-24 17:11:50 +0200290}
291
Sven Anders & Marcus Junker00b3b3e2006-10-16 18:18:09 +0200292/**
293 * pc87413_release:
294 * @inode: inode to board
295 * @file: file handle to board
296 *
297 * The watchdog has a configurable API. There is a religious dispute
298 * between people who want their watchdog to be able to shut down and
299 * those who want to be sure if the watchdog manager dies the machine
300 * reboots. In the former case we disable the counters, in the latter
301 * case you have to open it again very soon.
302 */
Sven Anders & Marcus Junker789fc0a2006-08-24 17:11:50 +0200303
Sven Anders & Marcus Junker00b3b3e2006-10-16 18:18:09 +0200304static int pc87413_release(struct inode *inode, struct file *file)
305{
306 /* Shut off the timer. */
Sven Anders & Marcus Junker789fc0a2006-08-24 17:11:50 +0200307
Sven Anders & Marcus Junker00b3b3e2006-10-16 18:18:09 +0200308 if (expect_close == 42) {
309 pc87413_disable();
Joe Perches27c766a2012-02-15 15:06:19 -0800310 pr_info("Watchdog disabled, sleeping again...\n");
Sven Anders & Marcus Junker00b3b3e2006-10-16 18:18:09 +0200311 } else {
Joe Perches27c766a2012-02-15 15:06:19 -0800312 pr_crit("Unexpected close, not stopping watchdog!\n");
Sven Anders & Marcus Junker00b3b3e2006-10-16 18:18:09 +0200313 pc87413_refresh();
314 }
Sven Anders & Marcus Junker00b3b3e2006-10-16 18:18:09 +0200315 clear_bit(0, &timer_enabled);
316 expect_close = 0;
Sven Anders & Marcus Junker00b3b3e2006-10-16 18:18:09 +0200317 return 0;
318}
Sven Anders & Marcus Junker789fc0a2006-08-24 17:11:50 +0200319
320/**
321 * pc87413_status:
322 *
Sven Anders & Marcus Junker00b3b3e2006-10-16 18:18:09 +0200323 * return, if the watchdog is enabled (timeout is set...)
Sven Anders & Marcus Junker789fc0a2006-08-24 17:11:50 +0200324 */
325
Sven Anders & Marcus Junker00b3b3e2006-10-16 18:18:09 +0200326
Sven Anders & Marcus Junker789fc0a2006-08-24 17:11:50 +0200327static int pc87413_status(void)
328{
Wim Van Sebroeck0835caa2006-10-23 18:21:52 +0200329 return 0; /* currently not supported */
Sven Anders & Marcus Junker789fc0a2006-08-24 17:11:50 +0200330}
331
332/**
333 * pc87413_write:
334 * @file: file handle to the watchdog
Sven Anders & Marcus Junker00b3b3e2006-10-16 18:18:09 +0200335 * @data: data buffer to write
336 * @len: length in bytes
Sven Anders & Marcus Junker789fc0a2006-08-24 17:11:50 +0200337 * @ppos: pointer to the position to write. No seeks allowed
338 *
339 * A write to a watchdog device is defined as a keepalive signal. Any
340 * write of data will do, as we we don't define content meaning.
341 */
342
Sven Anders & Marcus Junker00b3b3e2006-10-16 18:18:09 +0200343static ssize_t pc87413_write(struct file *file, const char __user *data,
344 size_t len, loff_t *ppos)
Sven Anders & Marcus Junker789fc0a2006-08-24 17:11:50 +0200345{
Sven Anders & Marcus Junker00b3b3e2006-10-16 18:18:09 +0200346 /* See if we got the magic character 'V' and reload the timer */
347 if (len) {
348 if (!nowayout) {
349 size_t i;
350
351 /* reset expect flag */
352 expect_close = 0;
353
Alan Coxaee334c2008-05-19 14:07:37 +0100354 /* scan to see whether or not we got the
355 magic character */
Sven Anders & Marcus Junker00b3b3e2006-10-16 18:18:09 +0200356 for (i = 0; i != len; i++) {
357 char c;
Wim Van Sebroeck7944d3a2008-08-06 20:19:41 +0000358 if (get_user(c, data + i))
Sven Anders & Marcus Junker00b3b3e2006-10-16 18:18:09 +0200359 return -EFAULT;
360 if (c == 'V')
361 expect_close = 42;
362 }
363 }
364
365 /* someone wrote to us, we should reload the timer */
366 pc87413_refresh();
Sven Anders & Marcus Junker789fc0a2006-08-24 17:11:50 +0200367 }
Sven Anders & Marcus Junker00b3b3e2006-10-16 18:18:09 +0200368 return len;
Sven Anders & Marcus Junker789fc0a2006-08-24 17:11:50 +0200369}
370
Sven Anders & Marcus Junker00b3b3e2006-10-16 18:18:09 +0200371/**
Sven Anders & Marcus Junker789fc0a2006-08-24 17:11:50 +0200372 * pc87413_ioctl:
Sven Anders & Marcus Junker789fc0a2006-08-24 17:11:50 +0200373 * @file: file handle to the device
374 * @cmd: watchdog command
375 * @arg: argument pointer
376 *
377 * The watchdog API defines a common set of functions for all watchdogs
378 * according to their available features. We only actually usefully support
379 * querying capabilities and current status.
380 */
381
Alan Coxaee334c2008-05-19 14:07:37 +0100382static long pc87413_ioctl(struct file *file, unsigned int cmd,
383 unsigned long arg)
Sven Anders & Marcus Junker789fc0a2006-08-24 17:11:50 +0200384{
Sven Anders & Marcus Junker00b3b3e2006-10-16 18:18:09 +0200385 int new_timeout;
386
387 union {
388 struct watchdog_info __user *ident;
389 int __user *i;
390 } uarg;
391
Wim Van Sebroeck42747d72009-12-26 18:55:22 +0000392 static const struct watchdog_info ident = {
Sven Anders & Marcus Junker00b3b3e2006-10-16 18:18:09 +0200393 .options = WDIOF_KEEPALIVEPING |
Alan Coxaee334c2008-05-19 14:07:37 +0100394 WDIOF_SETTIMEOUT |
395 WDIOF_MAGICCLOSE,
Sven Anders & Marcus Junker00b3b3e2006-10-16 18:18:09 +0200396 .firmware_version = 1,
Wim Van Sebroeck7944d3a2008-08-06 20:19:41 +0000397 .identity = "PC87413(HF/F) watchdog",
Sven Anders & Marcus Junker789fc0a2006-08-24 17:11:50 +0200398 };
399
Sven Anders & Marcus Junker00b3b3e2006-10-16 18:18:09 +0200400 uarg.i = (int __user *)arg;
Sven Anders & Marcus Junker789fc0a2006-08-24 17:11:50 +0200401
Alan Coxaee334c2008-05-19 14:07:37 +0100402 switch (cmd) {
403 case WDIOC_GETSUPPORT:
404 return copy_to_user(uarg.ident, &ident,
405 sizeof(ident)) ? -EFAULT : 0;
406 case WDIOC_GETSTATUS:
407 return put_user(pc87413_status(), uarg.i);
408 case WDIOC_GETBOOTSTATUS:
409 return put_user(0, uarg.i);
Wim Van Sebroeck0c060902008-07-18 11:41:17 +0000410 case WDIOC_SETOPTIONS:
411 {
412 int options, retval = -EINVAL;
413 if (get_user(options, uarg.i))
414 return -EFAULT;
415 if (options & WDIOS_DISABLECARD) {
416 pc87413_disable();
417 retval = 0;
418 }
419 if (options & WDIOS_ENABLECARD) {
420 pc87413_enable();
421 retval = 0;
422 }
423 return retval;
424 }
Alan Coxaee334c2008-05-19 14:07:37 +0100425 case WDIOC_KEEPALIVE:
426 pc87413_refresh();
Sven Anders & Marcus Junker00b3b3e2006-10-16 18:18:09 +0200427#ifdef DEBUG
Joe Perches27c766a2012-02-15 15:06:19 -0800428 pr_info(DPFX "keepalive\n");
Sven Anders & Marcus Junker789fc0a2006-08-24 17:11:50 +0200429#endif
Alan Coxaee334c2008-05-19 14:07:37 +0100430 return 0;
431 case WDIOC_SETTIMEOUT:
432 if (get_user(new_timeout, uarg.i))
433 return -EFAULT;
434 /* the API states this is given in secs */
435 new_timeout /= 60;
436 if (new_timeout < 0 || new_timeout > MAX_TIMEOUT)
437 return -EINVAL;
438 timeout = new_timeout;
439 pc87413_refresh();
440 /* fall through and return the new timeout... */
441 case WDIOC_GETTIMEOUT:
442 new_timeout = timeout * 60;
443 return put_user(new_timeout, uarg.i);
Alan Coxaee334c2008-05-19 14:07:37 +0100444 default:
445 return -ENOTTY;
Sven Anders & Marcus Junker789fc0a2006-08-24 17:11:50 +0200446 }
Sven Anders & Marcus Junker789fc0a2006-08-24 17:11:50 +0200447}
448
Sven Anders & Marcus Junker00b3b3e2006-10-16 18:18:09 +0200449/* -- Notifier funtions -----------------------------------------*/
450
Sven Anders & Marcus Junker789fc0a2006-08-24 17:11:50 +0200451/**
452 * notify_sys:
453 * @this: our notifier block
454 * @code: the event being reported
455 * @unused: unused
456 *
457 * Our notifier is called on system shutdowns. We want to turn the card
458 * off at reboot otherwise the machine will reboot again during memory
459 * test or worse yet during the following fsck. This would suck, in fact
460 * trust me - if it happens it does suck.
461 */
462
Sven Anders & Marcus Junker00b3b3e2006-10-16 18:18:09 +0200463static int pc87413_notify_sys(struct notifier_block *this,
464 unsigned long code,
465 void *unused)
Sven Anders & Marcus Junker789fc0a2006-08-24 17:11:50 +0200466{
Sven Anders & Marcus Junker00b3b3e2006-10-16 18:18:09 +0200467 if (code == SYS_DOWN || code == SYS_HALT)
Sven Anders & Marcus Junker789fc0a2006-08-24 17:11:50 +0200468 /* Turn the card off */
469 pc87413_disable();
Sven Anders & Marcus Junker789fc0a2006-08-24 17:11:50 +0200470 return NOTIFY_DONE;
471}
472
Sven Anders & Marcus Junker00b3b3e2006-10-16 18:18:09 +0200473/* -- Module's structures ---------------------------------------*/
Sven Anders & Marcus Junker789fc0a2006-08-24 17:11:50 +0200474
Arjan van de Ven2b8693c2007-02-12 00:55:32 -0800475static const struct file_operations pc87413_fops = {
Sven Anders & Marcus Junker789fc0a2006-08-24 17:11:50 +0200476 .owner = THIS_MODULE,
Sven Anders & Marcus Junker00b3b3e2006-10-16 18:18:09 +0200477 .llseek = no_llseek,
Sven Anders & Marcus Junker789fc0a2006-08-24 17:11:50 +0200478 .write = pc87413_write,
Alan Coxaee334c2008-05-19 14:07:37 +0100479 .unlocked_ioctl = pc87413_ioctl,
Sven Anders & Marcus Junker789fc0a2006-08-24 17:11:50 +0200480 .open = pc87413_open,
481 .release = pc87413_release,
482};
483
Alan Coxaee334c2008-05-19 14:07:37 +0100484static struct notifier_block pc87413_notifier = {
Sven Anders & Marcus Junker00b3b3e2006-10-16 18:18:09 +0200485 .notifier_call = pc87413_notify_sys,
486};
487
Alan Coxaee334c2008-05-19 14:07:37 +0100488static struct miscdevice pc87413_miscdev = {
Sven Anders & Marcus Junker00b3b3e2006-10-16 18:18:09 +0200489 .minor = WATCHDOG_MINOR,
490 .name = "watchdog",
Wim Van Sebroeck7944d3a2008-08-06 20:19:41 +0000491 .fops = &pc87413_fops,
Sven Anders & Marcus Junker789fc0a2006-08-24 17:11:50 +0200492};
493
Sven Anders & Marcus Junker00b3b3e2006-10-16 18:18:09 +0200494/* -- Module init functions -------------------------------------*/
Sven Anders & Marcus Junker789fc0a2006-08-24 17:11:50 +0200495
496/**
Wim Van Sebroeck5f3b2752011-02-23 20:04:38 +0000497 * pc87413_init: module's "constructor"
Sven Anders & Marcus Junker00b3b3e2006-10-16 18:18:09 +0200498 *
499 * Set up the WDT watchdog board. All we have to do is grab the
500 * resources we require and bitch if anyone beat us to them.
501 * The open() function will actually kick the board off.
502 */
503
504static int __init pc87413_init(void)
505{
506 int ret;
507
Joe Perches27c766a2012-02-15 15:06:19 -0800508 pr_info("Version " VERSION " at io 0x%X\n",
Alan Coxaee334c2008-05-19 14:07:37 +0100509 WDT_INDEX_IO_PORT);
Sven Anders & Marcus Junker00b3b3e2006-10-16 18:18:09 +0200510
Jonathan McDowell7ccdb942011-04-14 12:02:39 -0700511 if (!request_muxed_region(io, 2, MODNAME))
512 return -EBUSY;
Sven Anders & Marcus Junker00b3b3e2006-10-16 18:18:09 +0200513
514 ret = register_reboot_notifier(&pc87413_notifier);
515 if (ret != 0) {
Joe Perches27c766a2012-02-15 15:06:19 -0800516 pr_err("cannot register reboot notifier (err=%d)\n", ret);
Sven Anders & Marcus Junker00b3b3e2006-10-16 18:18:09 +0200517 }
518
519 ret = misc_register(&pc87413_miscdev);
Sven Anders & Marcus Junker00b3b3e2006-10-16 18:18:09 +0200520 if (ret != 0) {
Joe Perches27c766a2012-02-15 15:06:19 -0800521 pr_err("cannot register miscdev on minor=%d (err=%d)\n",
522 WATCHDOG_MINOR, ret);
Jonathan McDowell7ccdb942011-04-14 12:02:39 -0700523 goto reboot_unreg;
Sven Anders & Marcus Junker00b3b3e2006-10-16 18:18:09 +0200524 }
Joe Perches27c766a2012-02-15 15:06:19 -0800525 pr_info("initialized. timeout=%d min\n", timeout);
Jonathan McDowell7ccdb942011-04-14 12:02:39 -0700526
527 pc87413_select_wdt_out();
528 pc87413_enable_swc();
529 pc87413_get_swc_base_addr();
530
531 if (!request_region(swc_base_addr, 0x20, MODNAME)) {
Joe Perches27c766a2012-02-15 15:06:19 -0800532 pr_err("cannot request SWC region at 0x%x\n", swc_base_addr);
Jonathan McDowell7ccdb942011-04-14 12:02:39 -0700533 ret = -EBUSY;
534 goto misc_unreg;
535 }
536
Sven Anders & Marcus Junker00b3b3e2006-10-16 18:18:09 +0200537 pc87413_enable();
Jonathan McDowell7ccdb942011-04-14 12:02:39 -0700538
539 release_region(io, 2);
Sven Anders & Marcus Junker00b3b3e2006-10-16 18:18:09 +0200540 return 0;
Jonathan McDowell7ccdb942011-04-14 12:02:39 -0700541
542misc_unreg:
543 misc_deregister(&pc87413_miscdev);
544reboot_unreg:
545 unregister_reboot_notifier(&pc87413_notifier);
546 release_region(io, 2);
547 return ret;
Sven Anders & Marcus Junker00b3b3e2006-10-16 18:18:09 +0200548}
549
550/**
551 * pc87413_exit: module's "destructor"
Sven Anders & Marcus Junker789fc0a2006-08-24 17:11:50 +0200552 *
553 * Unload the watchdog. You cannot do this with any file handles open.
554 * If your watchdog is set to continue ticking on close and you unload
555 * it, well it keeps ticking. We won't get the interrupt but the board
556 * will not touch PC memory so all is fine. You just have to load a new
557 * module in 60 seconds or reboot.
558 */
559
Sven Anders & Marcus Junker00b3b3e2006-10-16 18:18:09 +0200560static void __exit pc87413_exit(void)
Sven Anders & Marcus Junker789fc0a2006-08-24 17:11:50 +0200561{
Sven Anders & Marcus Junker00b3b3e2006-10-16 18:18:09 +0200562 /* Stop the timer before we leave */
Alan Coxaee334c2008-05-19 14:07:37 +0100563 if (!nowayout) {
Sven Anders & Marcus Junker00b3b3e2006-10-16 18:18:09 +0200564 pc87413_disable();
Joe Perches27c766a2012-02-15 15:06:19 -0800565 pr_info("Watchdog disabled\n");
Sven Anders & Marcus Junker00b3b3e2006-10-16 18:18:09 +0200566 }
567
Sven Anders & Marcus Junker789fc0a2006-08-24 17:11:50 +0200568 misc_deregister(&pc87413_miscdev);
569 unregister_reboot_notifier(&pc87413_notifier);
Jonathan McDowell7ccdb942011-04-14 12:02:39 -0700570 release_region(swc_base_addr, 0x20);
Sven Anders & Marcus Junker00b3b3e2006-10-16 18:18:09 +0200571
Joe Perches27c766a2012-02-15 15:06:19 -0800572 pr_info("watchdog component driver removed\n");
Sven Anders & Marcus Junker789fc0a2006-08-24 17:11:50 +0200573}
574
Sven Anders & Marcus Junker789fc0a2006-08-24 17:11:50 +0200575module_init(pc87413_init);
576module_exit(pc87413_exit);
577
Wim Van Sebroeck143a2e52009-03-18 08:35:09 +0000578MODULE_AUTHOR("Sven Anders <anders@anduras.de>, "
579 "Marcus Junker <junker@anduras.de>,");
Sven Anders & Marcus Junker789fc0a2006-08-24 17:11:50 +0200580MODULE_DESCRIPTION("PC87413 WDT driver");
Sven Anders & Marcus Junker00b3b3e2006-10-16 18:18:09 +0200581MODULE_LICENSE("GPL");
582
Sven Anders & Marcus Junker789fc0a2006-08-24 17:11:50 +0200583MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
584
Sven Anders & Marcus Junker00b3b3e2006-10-16 18:18:09 +0200585module_param(io, int, 0);
Randy Dunlap76550d32010-05-01 09:46:15 -0700586MODULE_PARM_DESC(io, MODNAME " I/O port (default: "
587 __MODULE_STRING(IO_DEFAULT) ").");
Sven Anders & Marcus Junker00b3b3e2006-10-16 18:18:09 +0200588
589module_param(timeout, int, 0);
Alan Coxaee334c2008-05-19 14:07:37 +0100590MODULE_PARM_DESC(timeout,
591 "Watchdog timeout in minutes (default="
Randy Dunlap76550d32010-05-01 09:46:15 -0700592 __MODULE_STRING(DEFAULT_TIMEOUT) ").");
Sven Anders & Marcus Junker00b3b3e2006-10-16 18:18:09 +0200593
Wim Van Sebroeck86a1e182012-03-05 16:51:11 +0100594module_param(nowayout, bool, 0);
Alan Coxaee334c2008-05-19 14:07:37 +0100595MODULE_PARM_DESC(nowayout,
596 "Watchdog cannot be stopped once started (default="
597 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
Sven Anders & Marcus Junker00b3b3e2006-10-16 18:18:09 +0200598