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> | |
9540724c | 24 | #include <linux/of.h> |
1da177e4 LT |
25 | #include <linux/watchdog.h> |
26 | #include <linux/init.h> | |
27 | #include <linux/bitops.h> | |
089ab079 | 28 | #include <linux/uaccess.h> |
a09e64fb | 29 | #include <mach/hardware.h> |
1da177e4 | 30 | |
86a1e189 | 31 | static bool nowayout = WATCHDOG_NOWAYOUT; |
1da177e4 LT |
32 | static int heartbeat = 60; /* (secs) Default is 1 minute */ |
33 | static unsigned long wdt_status; | |
34 | static unsigned long boot_status; | |
9229376e | 35 | static DEFINE_SPINLOCK(wdt_lock); |
1da177e4 LT |
36 | |
37 | #define WDT_TICK_RATE (IXP4XX_PERIPHERAL_BUS_CLOCK * 1000000UL) | |
38 | ||
39 | #define WDT_IN_USE 0 | |
40 | #define WDT_OK_TO_CLOSE 1 | |
41 | ||
20d35f3e | 42 | static void wdt_enable(void) |
1da177e4 | 43 | { |
20d35f3e | 44 | spin_lock(&wdt_lock); |
1da177e4 LT |
45 | *IXP4XX_OSWK = IXP4XX_WDT_KEY; |
46 | *IXP4XX_OSWE = 0; | |
47 | *IXP4XX_OSWT = WDT_TICK_RATE * heartbeat; | |
48 | *IXP4XX_OSWE = IXP4XX_WDT_COUNT_ENABLE | IXP4XX_WDT_RESET_ENABLE; | |
49 | *IXP4XX_OSWK = 0; | |
20d35f3e | 50 | spin_unlock(&wdt_lock); |
1da177e4 LT |
51 | } |
52 | ||
20d35f3e | 53 | static void wdt_disable(void) |
1da177e4 | 54 | { |
20d35f3e | 55 | spin_lock(&wdt_lock); |
1da177e4 LT |
56 | *IXP4XX_OSWK = IXP4XX_WDT_KEY; |
57 | *IXP4XX_OSWE = 0; | |
58 | *IXP4XX_OSWK = 0; | |
20d35f3e | 59 | spin_unlock(&wdt_lock); |
1da177e4 LT |
60 | } |
61 | ||
20d35f3e | 62 | static int ixp4xx_wdt_open(struct inode *inode, struct file *file) |
1da177e4 LT |
63 | { |
64 | if (test_and_set_bit(WDT_IN_USE, &wdt_status)) | |
65 | return -EBUSY; | |
66 | ||
67 | clear_bit(WDT_OK_TO_CLOSE, &wdt_status); | |
1da177e4 | 68 | wdt_enable(); |
c5bf68fe | 69 | return stream_open(inode, file); |
1da177e4 LT |
70 | } |
71 | ||
72 | static ssize_t | |
73 | ixp4xx_wdt_write(struct file *file, const char *data, size_t len, loff_t *ppos) | |
74 | { | |
75 | if (len) { | |
76 | if (!nowayout) { | |
77 | size_t i; | |
78 | ||
79 | clear_bit(WDT_OK_TO_CLOSE, &wdt_status); | |
80 | ||
81 | for (i = 0; i != len; i++) { | |
82 | char c; | |
83 | ||
84 | if (get_user(c, data + i)) | |
85 | return -EFAULT; | |
86 | if (c == 'V') | |
87 | set_bit(WDT_OK_TO_CLOSE, &wdt_status); | |
88 | } | |
89 | } | |
90 | wdt_enable(); | |
91 | } | |
1da177e4 LT |
92 | return len; |
93 | } | |
94 | ||
42747d71 | 95 | static const struct watchdog_info ident = { |
1da177e4 LT |
96 | .options = WDIOF_CARDRESET | WDIOF_MAGICCLOSE | |
97 | WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING, | |
98 | .identity = "IXP4xx Watchdog", | |
99 | }; | |
100 | ||
101 | ||
20d35f3e AC |
102 | static long ixp4xx_wdt_ioctl(struct file *file, unsigned int cmd, |
103 | unsigned long arg) | |
1da177e4 | 104 | { |
795b89d2 | 105 | int ret = -ENOTTY; |
1da177e4 LT |
106 | int time; |
107 | ||
108 | switch (cmd) { | |
109 | case WDIOC_GETSUPPORT: | |
110 | ret = copy_to_user((struct watchdog_info *)arg, &ident, | |
111 | sizeof(ident)) ? -EFAULT : 0; | |
112 | break; | |
113 | ||
114 | case WDIOC_GETSTATUS: | |
115 | ret = put_user(0, (int *)arg); | |
116 | break; | |
117 | ||
118 | case WDIOC_GETBOOTSTATUS: | |
119 | ret = put_user(boot_status, (int *)arg); | |
120 | break; | |
121 | ||
0c06090c WVS |
122 | case WDIOC_KEEPALIVE: |
123 | wdt_enable(); | |
124 | ret = 0; | |
125 | break; | |
126 | ||
1da177e4 LT |
127 | case WDIOC_SETTIMEOUT: |
128 | ret = get_user(time, (int *)arg); | |
129 | if (ret) | |
130 | break; | |
131 | ||
132 | if (time <= 0 || time > 60) { | |
133 | ret = -EINVAL; | |
134 | break; | |
135 | } | |
136 | ||
137 | heartbeat = time; | |
138 | wdt_enable(); | |
bd490f82 | 139 | fallthrough; |
1da177e4 LT |
140 | |
141 | case WDIOC_GETTIMEOUT: | |
142 | ret = put_user(heartbeat, (int *)arg); | |
143 | break; | |
1da177e4 LT |
144 | } |
145 | return ret; | |
146 | } | |
147 | ||
20d35f3e | 148 | static int ixp4xx_wdt_release(struct inode *inode, struct file *file) |
1da177e4 | 149 | { |
20d35f3e | 150 | if (test_bit(WDT_OK_TO_CLOSE, &wdt_status)) |
1da177e4 | 151 | wdt_disable(); |
20d35f3e | 152 | else |
27c766aa | 153 | pr_crit("Device closed unexpectedly - timer will not stop\n"); |
1da177e4 LT |
154 | clear_bit(WDT_IN_USE, &wdt_status); |
155 | clear_bit(WDT_OK_TO_CLOSE, &wdt_status); | |
156 | ||
157 | return 0; | |
158 | } | |
159 | ||
160 | ||
7944d3a5 | 161 | static const struct file_operations ixp4xx_wdt_fops = { |
1da177e4 LT |
162 | .owner = THIS_MODULE, |
163 | .llseek = no_llseek, | |
164 | .write = ixp4xx_wdt_write, | |
20d35f3e | 165 | .unlocked_ioctl = ixp4xx_wdt_ioctl, |
b6dfb247 | 166 | .compat_ioctl = compat_ptr_ioctl, |
1da177e4 LT |
167 | .open = ixp4xx_wdt_open, |
168 | .release = ixp4xx_wdt_release, | |
169 | }; | |
170 | ||
7944d3a5 | 171 | static struct miscdevice ixp4xx_wdt_miscdev = { |
1da177e4 | 172 | .minor = WATCHDOG_MINOR, |
2dab3cab | 173 | .name = "watchdog", |
1da177e4 LT |
174 | .fops = &ixp4xx_wdt_fops, |
175 | }; | |
176 | ||
177 | static int __init ixp4xx_wdt_init(void) | |
178 | { | |
179 | int ret; | |
1da177e4 | 180 | |
9540724c LW |
181 | /* |
182 | * FIXME: we bail out on device tree boot but this really needs | |
183 | * to be fixed in a nicer way: this registers the MDIO bus before | |
184 | * even matching the driver infrastructure, we should only probe | |
185 | * detected hardware. | |
186 | */ | |
187 | if (of_have_populated_dt()) | |
188 | return -ENODEV; | |
0ba8b9b2 | 189 | if (!(read_cpuid_id() & 0xf) && !cpu_is_ixp46x()) { |
27c766aa | 190 | pr_err("Rev. A0 IXP42x CPU detected - watchdog disabled\n"); |
1da177e4 LT |
191 | |
192 | return -ENODEV; | |
193 | } | |
1da177e4 LT |
194 | boot_status = (*IXP4XX_OSST & IXP4XX_OSST_TIMER_WARM_RESET) ? |
195 | WDIOF_CARDRESET : 0; | |
1da177e4 LT |
196 | ret = misc_register(&ixp4xx_wdt_miscdev); |
197 | if (ret == 0) | |
27c766aa | 198 | pr_info("timer heartbeat %d sec\n", heartbeat); |
1da177e4 LT |
199 | return ret; |
200 | } | |
201 | ||
202 | static void __exit ixp4xx_wdt_exit(void) | |
203 | { | |
204 | misc_deregister(&ixp4xx_wdt_miscdev); | |
205 | } | |
206 | ||
207 | ||
208 | module_init(ixp4xx_wdt_init); | |
209 | module_exit(ixp4xx_wdt_exit); | |
210 | ||
211 | MODULE_AUTHOR("Deepak Saxena <dsaxena@plexity.net>"); | |
212 | MODULE_DESCRIPTION("IXP4xx Network Processor Watchdog"); | |
213 | ||
214 | module_param(heartbeat, int, 0); | |
215 | MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat in seconds (default 60s)"); | |
216 | ||
86a1e189 | 217 | module_param(nowayout, bool, 0); |
1da177e4 LT |
218 | MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started"); |
219 | ||
220 | MODULE_LICENSE("GPL"); |