Orange Pi5 kernel

^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   1) // SPDX-License-Identifier: GPL-2.0-or-later
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   2) /* drivers/char/watchdog/scx200_wdt.c
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   3) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   4)    National Semiconductor SCx200 Watchdog support
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   5) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   6)    Copyright (c) 2001,2002 Christer Weinigel <wingel@nano-system.com>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   7) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   8)    Some code taken from:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   9)    National Semiconductor PC87307/PC97307 (ala SC1200) WDT driver
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  10)    (c) Copyright 2002 Zwane Mwaikambo <zwane@commfireservices.com>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  11) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  12) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  13)    The author(s) of this software shall not be held liable for damages
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  14)    of any nature resulting due to the use of this software. This
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  15)    software is provided AS-IS with no warranties. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  16) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  17) #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  18) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  19) #include <linux/module.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  20) #include <linux/moduleparam.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  21) #include <linux/init.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  22) #include <linux/miscdevice.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  23) #include <linux/watchdog.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  24) #include <linux/notifier.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  25) #include <linux/reboot.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  26) #include <linux/fs.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  27) #include <linux/ioport.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  28) #include <linux/scx200.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  29) #include <linux/uaccess.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  30) #include <linux/io.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  31) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  32) #define DEBUG
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  33) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  34) MODULE_AUTHOR("Christer Weinigel <wingel@nano-system.com>");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  35) MODULE_DESCRIPTION("NatSemi SCx200 Watchdog Driver");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  36) MODULE_LICENSE("GPL");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  37) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  38) static int margin = 60;		/* in seconds */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  39) module_param(margin, int, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  40) MODULE_PARM_DESC(margin, "Watchdog margin in seconds");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  41) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  42) static bool nowayout = WATCHDOG_NOWAYOUT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  43) module_param(nowayout, bool, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  44) MODULE_PARM_DESC(nowayout, "Disable watchdog shutdown on close");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  45) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  46) static u16 wdto_restart;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  47) static char expect_close;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  48) static unsigned long open_lock;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  49) static DEFINE_SPINLOCK(scx_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  50) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  51) /* Bits of the WDCNFG register */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  52) #define W_ENABLE 0x00fa		/* Enable watchdog */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  53) #define W_DISABLE 0x0000	/* Disable watchdog */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  54) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  55) /* The scaling factor for the timer, this depends on the value of W_ENABLE */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  56) #define W_SCALE (32768/1024)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  57) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  58) static void scx200_wdt_ping(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  59) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  60) 	spin_lock(&scx_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  61) 	outw(wdto_restart, scx200_cb_base + SCx200_WDT_WDTO);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  62) 	spin_unlock(&scx_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  63) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  64) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  65) static void scx200_wdt_update_margin(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  66) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  67) 	pr_info("timer margin %d seconds\n", margin);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  68) 	wdto_restart = margin * W_SCALE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  69) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  70) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  71) static void scx200_wdt_enable(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  72) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  73) 	pr_debug("enabling watchdog timer, wdto_restart = %d\n", wdto_restart);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  74) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  75) 	spin_lock(&scx_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  76) 	outw(0, scx200_cb_base + SCx200_WDT_WDTO);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  77) 	outb(SCx200_WDT_WDSTS_WDOVF, scx200_cb_base + SCx200_WDT_WDSTS);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  78) 	outw(W_ENABLE, scx200_cb_base + SCx200_WDT_WDCNFG);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  79) 	spin_unlock(&scx_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  80) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  81) 	scx200_wdt_ping();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  82) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  83) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  84) static void scx200_wdt_disable(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  85) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  86) 	pr_debug("disabling watchdog timer\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  87) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  88) 	spin_lock(&scx_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  89) 	outw(0, scx200_cb_base + SCx200_WDT_WDTO);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  90) 	outb(SCx200_WDT_WDSTS_WDOVF, scx200_cb_base + SCx200_WDT_WDSTS);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  91) 	outw(W_DISABLE, scx200_cb_base + SCx200_WDT_WDCNFG);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  92) 	spin_unlock(&scx_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  93) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  94) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  95) static int scx200_wdt_open(struct inode *inode, struct file *file)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  96) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  97) 	/* only allow one at a time */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  98) 	if (test_and_set_bit(0, &open_lock))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  99) 		return -EBUSY;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) 	scx200_wdt_enable();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) 	return stream_open(inode, file);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) static int scx200_wdt_release(struct inode *inode, struct file *file)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) 	if (expect_close != 42)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) 		pr_warn("watchdog device closed unexpectedly, will not disable the watchdog timer\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) 	else if (!nowayout)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) 		scx200_wdt_disable();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) 	expect_close = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) 	clear_bit(0, &open_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) static int scx200_wdt_notify_sys(struct notifier_block *this,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) 				      unsigned long code, void *unused)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) 	if (code == SYS_HALT || code == SYS_POWER_OFF)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) 		if (!nowayout)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) 			scx200_wdt_disable();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) 	return NOTIFY_DONE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) static struct notifier_block scx200_wdt_notifier = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) 	.notifier_call = scx200_wdt_notify_sys,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) static ssize_t scx200_wdt_write(struct file *file, const char __user *data,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) 				     size_t len, loff_t *ppos)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) 	/* check for a magic close character */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) 	if (len) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) 		size_t i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) 		scx200_wdt_ping();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) 		expect_close = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) 		for (i = 0; i < len; ++i) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) 			char c;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) 			if (get_user(c, data + i))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) 				return -EFAULT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) 			if (c == 'V')
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) 				expect_close = 42;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) 		return len;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) static long scx200_wdt_ioctl(struct file *file, unsigned int cmd,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) 							unsigned long arg)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) 	void __user *argp = (void __user *)arg;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159) 	int __user *p = argp;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) 	static const struct watchdog_info ident = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) 		.identity = "NatSemi SCx200 Watchdog",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) 		.firmware_version = 1,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) 		.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING |
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164) 						WDIOF_MAGICCLOSE,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) 	};
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) 	int new_margin;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) 	switch (cmd) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169) 	case WDIOC_GETSUPPORT:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170) 		if (copy_to_user(argp, &ident, sizeof(ident)))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) 			return -EFAULT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172) 		return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173) 	case WDIOC_GETSTATUS:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174) 	case WDIOC_GETBOOTSTATUS:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175) 		if (put_user(0, p))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176) 			return -EFAULT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177) 		return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178) 	case WDIOC_KEEPALIVE:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179) 		scx200_wdt_ping();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) 		return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181) 	case WDIOC_SETTIMEOUT:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182) 		if (get_user(new_margin, p))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183) 			return -EFAULT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184) 		if (new_margin < 1)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185) 			return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186) 		margin = new_margin;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187) 		scx200_wdt_update_margin();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188) 		scx200_wdt_ping();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189) 		fallthrough;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190) 	case WDIOC_GETTIMEOUT:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191) 		if (put_user(margin, p))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192) 			return -EFAULT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193) 		return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194) 	default:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195) 		return -ENOTTY;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 197) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 198) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 199) static const struct file_operations scx200_wdt_fops = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 200) 	.owner = THIS_MODULE,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 201) 	.llseek = no_llseek,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 202) 	.write = scx200_wdt_write,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 203) 	.unlocked_ioctl = scx200_wdt_ioctl,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 204) 	.compat_ioctl	= compat_ptr_ioctl,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 205) 	.open = scx200_wdt_open,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 206) 	.release = scx200_wdt_release,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 207) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 208) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 209) static struct miscdevice scx200_wdt_miscdev = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 210) 	.minor = WATCHDOG_MINOR,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 211) 	.name = "watchdog",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 212) 	.fops = &scx200_wdt_fops,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 213) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 214) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 215) static int __init scx200_wdt_init(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 216) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 217) 	int r;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 218) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 219) 	pr_debug("NatSemi SCx200 Watchdog Driver\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 220) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 221) 	/* check that we have found the configuration block */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 222) 	if (!scx200_cb_present())
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 223) 		return -ENODEV;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 224) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 225) 	if (!request_region(scx200_cb_base + SCx200_WDT_OFFSET,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 226) 			    SCx200_WDT_SIZE,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 227) 			    "NatSemi SCx200 Watchdog")) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 228) 		pr_warn("watchdog I/O region busy\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 229) 		return -EBUSY;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 230) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 231) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 232) 	scx200_wdt_update_margin();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 233) 	scx200_wdt_disable();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 234) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 235) 	r = register_reboot_notifier(&scx200_wdt_notifier);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 236) 	if (r) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 237) 		pr_err("unable to register reboot notifier\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 238) 		release_region(scx200_cb_base + SCx200_WDT_OFFSET,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 239) 				SCx200_WDT_SIZE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 240) 		return r;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 241) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 242) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 243) 	r = misc_register(&scx200_wdt_miscdev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 244) 	if (r) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 245) 		unregister_reboot_notifier(&scx200_wdt_notifier);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 246) 		release_region(scx200_cb_base + SCx200_WDT_OFFSET,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 247) 				SCx200_WDT_SIZE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 248) 		return r;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 249) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 250) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 251) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 252) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 253) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 254) static void __exit scx200_wdt_cleanup(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 255) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 256) 	misc_deregister(&scx200_wdt_miscdev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 257) 	unregister_reboot_notifier(&scx200_wdt_notifier);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 258) 	release_region(scx200_cb_base + SCx200_WDT_OFFSET,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 259) 		       SCx200_WDT_SIZE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 260) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 261) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 262) module_init(scx200_wdt_init);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 263) module_exit(scx200_wdt_cleanup);