Orange Pi5 kernel

^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   1) // SPDX-License-Identifier: GPL-2.0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   2) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   3)  *	NANO7240 SBC Watchdog device driver
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   4)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   5)  *	Based on w83877f.c by Scott Jennings,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   6)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   7)  *	(c) Copyright 2007  Gilles GIGAN <gilles.gigan@jcu.edu.au>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   8)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   9) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  10) #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  11) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  12) #include <linux/fs.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  13) #include <linux/init.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  14) #include <linux/ioport.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  15) #include <linux/jiffies.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  16) #include <linux/module.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  17) #include <linux/moduleparam.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  18) #include <linux/miscdevice.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  19) #include <linux/notifier.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  20) #include <linux/reboot.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  21) #include <linux/types.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  22) #include <linux/watchdog.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  23) #include <linux/io.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  24) #include <linux/uaccess.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  25) #include <linux/atomic.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  26) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  27) #define SBC7240_ENABLE_PORT		0x443
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  28) #define SBC7240_DISABLE_PORT		0x043
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  29) #define SBC7240_SET_TIMEOUT_PORT	SBC7240_ENABLE_PORT
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  30) #define SBC7240_MAGIC_CHAR		'V'
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  31) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  32) #define SBC7240_TIMEOUT		30
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  33) #define SBC7240_MAX_TIMEOUT		255
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  34) static int timeout = SBC7240_TIMEOUT;	/* in seconds */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  35) module_param(timeout, int, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  36) MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds. (1<=timeout<="
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  37) 		 __MODULE_STRING(SBC7240_MAX_TIMEOUT) ", default="
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  38) 		 __MODULE_STRING(SBC7240_TIMEOUT) ")");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  39) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  40) static bool nowayout = WATCHDOG_NOWAYOUT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  41) module_param(nowayout, bool, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  42) MODULE_PARM_DESC(nowayout, "Disable watchdog when closing device file");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  43) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  44) #define SBC7240_OPEN_STATUS_BIT		0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  45) #define SBC7240_ENABLED_STATUS_BIT	1
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  46) #define SBC7240_EXPECT_CLOSE_STATUS_BIT	2
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  47) static unsigned long wdt_status;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  48) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  49) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  50)  * Utility routines
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  51)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  52) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  53) static void wdt_disable(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  54) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  55) 	/* disable the watchdog */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  56) 	if (test_and_clear_bit(SBC7240_ENABLED_STATUS_BIT, &wdt_status)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  57) 		inb_p(SBC7240_DISABLE_PORT);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  58) 		pr_info("Watchdog timer is now disabled\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  59) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  60) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  61) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  62) static void wdt_enable(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  63) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  64) 	/* enable the watchdog */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  65) 	if (!test_and_set_bit(SBC7240_ENABLED_STATUS_BIT, &wdt_status)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  66) 		inb_p(SBC7240_ENABLE_PORT);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  67) 		pr_info("Watchdog timer is now enabled\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  68) 	}
^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 int wdt_set_timeout(int t)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  72) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  73) 	if (t < 1 || t > SBC7240_MAX_TIMEOUT) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  74) 		pr_err("timeout value must be 1<=x<=%d\n", SBC7240_MAX_TIMEOUT);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  75) 		return -1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  76) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  77) 	/* set the timeout */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  78) 	outb_p((unsigned)t, SBC7240_SET_TIMEOUT_PORT);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  79) 	timeout = t;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  80) 	pr_info("timeout set to %d seconds\n", t);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  81) 	return 0;
^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) /* Whack the dog */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  85) static inline void wdt_keepalive(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  86) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  87) 	if (test_bit(SBC7240_ENABLED_STATUS_BIT, &wdt_status))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  88) 		inb_p(SBC7240_ENABLE_PORT);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  89) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  90) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  91) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  92)  * /dev/watchdog handling
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  93)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  94) static ssize_t fop_write(struct file *file, const char __user *buf,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  95) 			 size_t count, loff_t *ppos)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  96) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  97) 	size_t i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  98) 	char c;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  99) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) 	if (count) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) 		if (!nowayout) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) 			clear_bit(SBC7240_EXPECT_CLOSE_STATUS_BIT,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) 				&wdt_status);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) 			/* is there a magic char ? */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) 			for (i = 0; i != count; i++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) 				if (get_user(c, buf + i))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) 					return -EFAULT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) 				if (c == SBC7240_MAGIC_CHAR) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) 					set_bit(SBC7240_EXPECT_CLOSE_STATUS_BIT,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) 						&wdt_status);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) 					break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) 				}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) 			}
^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) 		wdt_keepalive();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) 	return count;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) static int fop_open(struct inode *inode, struct file *file)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) 	if (test_and_set_bit(SBC7240_OPEN_STATUS_BIT, &wdt_status))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) 		return -EBUSY;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) 	wdt_enable();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) 	return stream_open(inode, file);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) static int fop_close(struct inode *inode, struct file *file)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) 	if (test_and_clear_bit(SBC7240_EXPECT_CLOSE_STATUS_BIT, &wdt_status)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) 	    || !nowayout) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) 		wdt_disable();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) 	} else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) 		pr_crit("Unexpected close, not stopping watchdog!\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) 		wdt_keepalive();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) 	clear_bit(SBC7240_OPEN_STATUS_BIT, &wdt_status);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) static const struct watchdog_info ident = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) 	.options = WDIOF_KEEPALIVEPING|
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) 		   WDIOF_SETTIMEOUT|
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) 		   WDIOF_MAGICCLOSE,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) 	.firmware_version = 1,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) 	.identity = "SBC7240",
^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) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) static long fop_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) 	switch (cmd) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159) 	case WDIOC_GETSUPPORT:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) 		return copy_to_user((void __user *)arg, &ident, sizeof(ident))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) 						 ? -EFAULT : 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) 	case WDIOC_GETSTATUS:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) 	case WDIOC_GETBOOTSTATUS:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164) 		return put_user(0, (int __user *)arg);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) 	case WDIOC_SETOPTIONS:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) 	{
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) 		int options;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) 		int retval = -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170) 		if (get_user(options, (int __user *)arg))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) 			return -EFAULT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173) 		if (options & WDIOS_DISABLECARD) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174) 			wdt_disable();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175) 			retval = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178) 		if (options & WDIOS_ENABLECARD) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179) 			wdt_enable();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) 			retval = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183) 		return retval;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185) 	case WDIOC_KEEPALIVE:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186) 		wdt_keepalive();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187) 		return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188) 	case WDIOC_SETTIMEOUT:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189) 	{
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190) 		int new_timeout;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192) 		if (get_user(new_timeout, (int __user *)arg))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193) 			return -EFAULT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195) 		if (wdt_set_timeout(new_timeout))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196) 			return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 197) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 198) 		fallthrough;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 199) 	case WDIOC_GETTIMEOUT:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 200) 		return put_user(timeout, (int __user *)arg);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 201) 	default:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 202) 		return -ENOTTY;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 203) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 204) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 205) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 206) static const struct file_operations wdt_fops = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 207) 	.owner = THIS_MODULE,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 208) 	.llseek = no_llseek,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 209) 	.write = fop_write,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 210) 	.open = fop_open,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 211) 	.release = fop_close,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 212) 	.unlocked_ioctl = fop_ioctl,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 213) 	.compat_ioctl = compat_ptr_ioctl,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 214) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 215) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 216) static struct miscdevice wdt_miscdev = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 217) 	.minor = WATCHDOG_MINOR,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 218) 	.name = "watchdog",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 219) 	.fops = &wdt_fops,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 220) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 221) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 222) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 223)  *	Notifier for system down
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 224)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 225) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 226) static int wdt_notify_sys(struct notifier_block *this, unsigned long code,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 227) 			  void *unused)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 228) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 229) 	if (code == SYS_DOWN || code == SYS_HALT)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 230) 		wdt_disable();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 231) 	return NOTIFY_DONE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 232) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 233) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 234) static struct notifier_block wdt_notifier = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 235) 	.notifier_call = wdt_notify_sys,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 236) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 237) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 238) static void __exit sbc7240_wdt_unload(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 239) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 240) 	pr_info("Removing watchdog\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 241) 	misc_deregister(&wdt_miscdev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 242) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 243) 	unregister_reboot_notifier(&wdt_notifier);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 244) 	release_region(SBC7240_ENABLE_PORT, 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 245) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 246) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 247) static int __init sbc7240_wdt_init(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 248) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 249) 	int rc = -EBUSY;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 250) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 251) 	if (!request_region(SBC7240_ENABLE_PORT, 1, "SBC7240 WDT")) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 252) 		pr_err("I/O address 0x%04x already in use\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 253) 		       SBC7240_ENABLE_PORT);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 254) 		rc = -EIO;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 255) 		goto err_out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 256) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 257) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 258) 	/* The IO port 0x043 used to disable the watchdog
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 259) 	 * is already claimed by the system timer, so we
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 260) 	 * can't request_region() it ...*/
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 261) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 262) 	if (timeout < 1 || timeout > SBC7240_MAX_TIMEOUT) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 263) 		timeout = SBC7240_TIMEOUT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 264) 		pr_info("timeout value must be 1<=x<=%d, using %d\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 265) 			SBC7240_MAX_TIMEOUT, timeout);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 266) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 267) 	wdt_set_timeout(timeout);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 268) 	wdt_disable();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 269) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 270) 	rc = register_reboot_notifier(&wdt_notifier);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 271) 	if (rc) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 272) 		pr_err("cannot register reboot notifier (err=%d)\n", rc);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 273) 		goto err_out_region;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 274) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 275) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 276) 	rc = misc_register(&wdt_miscdev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 277) 	if (rc) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 278) 		pr_err("cannot register miscdev on minor=%d (err=%d)\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 279) 		       wdt_miscdev.minor, rc);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 280) 		goto err_out_reboot_notifier;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 281) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 282) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 283) 	pr_info("Watchdog driver for SBC7240 initialised (nowayout=%d)\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 284) 		nowayout);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 285) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 286) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 287) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 288) err_out_reboot_notifier:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 289) 	unregister_reboot_notifier(&wdt_notifier);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 290) err_out_region:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 291) 	release_region(SBC7240_ENABLE_PORT, 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 292) err_out:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 293) 	return rc;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 294) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 295) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 296) module_init(sbc7240_wdt_init);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 297) module_exit(sbc7240_wdt_unload);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 298) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 299) MODULE_AUTHOR("Gilles Gigan");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 300) MODULE_DESCRIPTION("Watchdog device driver for single board"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 301) 		   " computers EPIC Nano 7240 from iEi");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 302) MODULE_LICENSE("GPL");