Commit | Line | Data |
---|---|---|
1da177e4 | 1 | /* |
f30c2269 | 2 | * drivers/char/watchdog/ixp4xx_wdt.c |
1da177e4 LT |
3 | * |
4 | * Watchdog driver for Intel IXP4xx network processors | |
5 | * | |
6 | * Author: Deepak Saxena <dsaxena@plexity.net> | |
7 | * | |
8 | * Copyright 2004 (c) MontaVista, Software, Inc. | |
9 | * Based on sa1100 driver, Copyright (C) 2000 Oleg Drokin <green@crimea.edu> | |
10 | * | |
11 | * This file is licensed under the terms of the GNU General Public | |
12 | * License version 2. This program is licensed "as is" without any | |
13 | * warranty of any kind, whether express or implied. | |
14 | */ | |
15 | ||
27c766aa JP |
16 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
17 | ||
1da177e4 LT |
18 | #include <linux/module.h> |
19 | #include <linux/moduleparam.h> | |
20 | #include <linux/types.h> | |
21 | #include <linux/kernel.h> | |
22 | #include <linux/fs.h> | |
23 | #include <linux/miscdevice.h> | |
24 | #include <linux/watchdog.h> | |
25 | #include <linux/init.h> | |
26 | #include <linux/bitops.h> | |
089ab079 | 27 | #include <linux/uaccess.h> |
a09e64fb | 28 | #include <mach/hardware.h> |
1da177e4 | 29 | |
86a1e189 | 30 | static bool nowayout = WATCHDOG_NOWAYOUT; |
1da177e4 LT |
31 | static int heartbeat = 60; /* (secs) Default is 1 minute */ |
32 | static unsigned long wdt_status; | |
33 | static unsigned long boot_status; | |
9229376e | 34 | static DEFINE_SPINLOCK(wdt_lock); |
1da177e4 LT |
35 | |
36 | #define WDT_TICK_RATE (IXP4XX_PERIPHERAL_BUS_CLOCK * 1000000UL) | |
37 | ||
38 | #define WDT_IN_USE 0 | |
39 | #define WDT_OK_TO_CLOSE 1 | |
40 | ||
20d35f3e | 41 | static void wdt_enable(void) |
1da177e4 | 42 | { |
20d35f3e | 43 | spin_lock(&wdt_lock); |
1da177e4 LT |
44 | *IXP4XX_OSWK = IXP4XX_WDT_KEY; |
45 | *IXP4XX_OSWE = 0; | |
46 | *IXP4XX_OSWT = WDT_TICK_RATE * heartbeat; | |
47 | *IXP4XX_OSWE = IXP4XX_WDT_COUNT_ENABLE | IXP4XX_WDT_RESET_ENABLE; | |
48 | *IXP4XX_OSWK = 0; | |
20d35f3e | 49 | spin_unlock(&wdt_lock); |
1da177e4 LT |
50 | } |
51 | ||
20d35f3e | 52 | static void wdt_disable(void) |
1da177e4 | 53 | { |
20d35f3e | 54 | spin_lock(&wdt_lock); |
1da177e4 LT |
55 | *IXP4XX_OSWK = IXP4XX_WDT_KEY; |
56 | *IXP4XX_OSWE = 0; | |
57 | *IXP4XX_OSWK = 0; | |
20d35f3e | 58 | spin_unlock(&wdt_lock); |
1da177e4 LT |
59 | } |
60 | ||
20d35f3e | 61 | static int ixp4xx_wdt_open(struct inode *inode, struct file *file) |
1da177e4 LT |
62 | { |
63 | if (test_and_set_bit(WDT_IN_USE, &wdt_status)) | |
64 | return -EBUSY; | |
65 | ||
66 | clear_bit(WDT_OK_TO_CLOSE, &wdt_status); | |
1da177e4 | 67 | wdt_enable(); |
1da177e4 LT |
68 | return nonseekable_open(inode, file); |
69 | } | |
70 | ||
71 | static ssize_t | |
72 | ixp4xx_wdt_write(struct file *file, const char *data, size_t len, loff_t *ppos) | |
73 | { | |
74 | if (len) { | |
75 | if (!nowayout) { | |
76 | size_t i; | |
77 | ||
78 | clear_bit(WDT_OK_TO_CLOSE, &wdt_status); | |
79 | ||
80 | for (i = 0; i != len; i++) { | |
81 | char c; | |
82 | ||
83 | if (get_user(c, data + i)) | |
84 | return -EFAULT; | |
85 | if (c == 'V') | |
86 | set_bit(WDT_OK_TO_CLOSE, &wdt_status); | |
87 | } | |
88 | } | |
89 | wdt_enable(); | |
90 | } | |
1da177e4 LT |
91 | return len; |
92 | } | |
93 | ||
42747d71 | 94 | static const struct watchdog_info ident = { |
1da177e4 LT |
95 | .options = WDIOF_CARDRESET | WDIOF_MAGICCLOSE | |
96 | WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING, | |
97 | .identity = "IXP4xx Watchdog", | |
98 | }; | |
99 | ||
100 | ||
20d35f3e AC |
101 | static long ixp4xx_wdt_ioctl(struct file *file, unsigned int cmd, |
102 | unsigned long arg) | |
1da177e4 | 103 | { |
795b89d2 | 104 | int ret = -ENOTTY; |
1da177e4 LT |
105 | int time; |
106 | ||
107 | switch (cmd) { | |
108 | case WDIOC_GETSUPPORT: | |
109 | ret = copy_to_user((struct watchdog_info *)arg, &ident, | |
110 | sizeof(ident)) ? -EFAULT : 0; | |
111 | break; | |
112 | ||
113 | case WDIOC_GETSTATUS: | |
114 | ret = put_user(0, (int *)arg); | |
115 | break; | |
116 | ||
117 | case WDIOC_GETBOOTSTATUS: | |
118 | ret = put_user(boot_status, (int *)arg); | |
119 | break; | |
120 | ||
0c06090c WVS |
121 | case WDIOC_KEEPALIVE: |
122 | wdt_enable(); | |
123 | ret = 0; | |
124 | break; | |
125 | ||
1da177e4 LT |
126 | case WDIOC_SETTIMEOUT: |
127 | ret = get_user(time, (int *)arg); | |
128 | if (ret) | |
129 | break; | |
130 | ||
131 | if (time <= 0 || time > 60) { | |
132 | ret = -EINVAL; | |
133 | break; | |
134 | } | |
135 | ||
136 | heartbeat = time; | |
137 | wdt_enable(); | |
138 | /* Fall through */ | |
139 | ||
140 | case WDIOC_GETTIMEOUT: | |
141 | ret = put_user(heartbeat, (int *)arg); | |
142 | break; | |
1da177e4 LT |
143 | } |
144 | return ret; | |
145 | } | |
146 | ||
20d35f3e | 147 | static int ixp4xx_wdt_release(struct inode *inode, struct file *file) |
1da177e4 | 148 | { |
20d35f3e | 149 | if (test_bit(WDT_OK_TO_CLOSE, &wdt_status)) |
1da177e4 | 150 | wdt_disable(); |
20d35f3e | 151 | else |
27c766aa | 152 | pr_crit("Device closed unexpectedly - timer will not stop\n"); |
1da177e4 LT |
153 | clear_bit(WDT_IN_USE, &wdt_status); |
154 | clear_bit(WDT_OK_TO_CLOSE, &wdt_status); | |
155 | ||
156 | return 0; | |
157 | } | |
158 | ||
159 | ||
7944d3a5 | 160 | static const struct file_operations ixp4xx_wdt_fops = { |
1da177e4 LT |
161 | .owner = THIS_MODULE, |
162 | .llseek = no_llseek, | |
163 | .write = ixp4xx_wdt_write, | |
20d35f3e | 164 | .unlocked_ioctl = ixp4xx_wdt_ioctl, |
1da177e4 LT |
165 | .open = ixp4xx_wdt_open, |
166 | .release = ixp4xx_wdt_release, | |
167 | }; | |
168 | ||
7944d3a5 | 169 | static struct miscdevice ixp4xx_wdt_miscdev = { |
1da177e4 | 170 | .minor = WATCHDOG_MINOR, |
2dab3cab | 171 | .name = "watchdog", |
1da177e4 LT |
172 | .fops = &ixp4xx_wdt_fops, |
173 | }; | |
174 | ||
175 | static int __init ixp4xx_wdt_init(void) | |
176 | { | |
177 | int ret; | |
1da177e4 | 178 | |
0ba8b9b2 | 179 | if (!(read_cpuid_id() & 0xf) && !cpu_is_ixp46x()) { |
27c766aa | 180 | pr_err("Rev. A0 IXP42x CPU detected - watchdog disabled\n"); |
1da177e4 LT |
181 | |
182 | return -ENODEV; | |
183 | } | |
1da177e4 LT |
184 | boot_status = (*IXP4XX_OSST & IXP4XX_OSST_TIMER_WARM_RESET) ? |
185 | WDIOF_CARDRESET : 0; | |
1da177e4 LT |
186 | ret = misc_register(&ixp4xx_wdt_miscdev); |
187 | if (ret == 0) | |
27c766aa | 188 | pr_info("timer heartbeat %d sec\n", heartbeat); |
1da177e4 LT |
189 | return ret; |
190 | } | |
191 | ||
192 | static void __exit ixp4xx_wdt_exit(void) | |
193 | { | |
194 | misc_deregister(&ixp4xx_wdt_miscdev); | |
195 | } | |
196 | ||
197 | ||
198 | module_init(ixp4xx_wdt_init); | |
199 | module_exit(ixp4xx_wdt_exit); | |
200 | ||
201 | MODULE_AUTHOR("Deepak Saxena <dsaxena@plexity.net>"); | |
202 | MODULE_DESCRIPTION("IXP4xx Network Processor Watchdog"); | |
203 | ||
204 | module_param(heartbeat, int, 0); | |
205 | MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat in seconds (default 60s)"); | |
206 | ||
86a1e189 | 207 | module_param(nowayout, bool, 0); |
1da177e4 LT |
208 | MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started"); |
209 | ||
210 | MODULE_LICENSE("GPL"); |