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a2f40ccd | 1 | /* |
a2f40ccd KG |
2 | * Watchdog timer for PowerPC Book-E systems |
3 | * | |
4 | * Author: Matthew McClintock | |
4c8d3d99 | 5 | * Maintainer: Kumar Gala <galak@kernel.crashing.org> |
a2f40ccd | 6 | * |
f172ddc6 | 7 | * Copyright 2005, 2008 Freescale Semiconductor Inc. |
a2f40ccd KG |
8 | * |
9 | * This program is free software; you can redistribute it and/or modify it | |
10 | * under the terms of the GNU General Public License as published by the | |
11 | * Free Software Foundation; either version 2 of the License, or (at your | |
12 | * option) any later version. | |
13 | */ | |
14 | ||
a2f40ccd KG |
15 | #include <linux/module.h> |
16 | #include <linux/fs.h> | |
f172ddc6 | 17 | #include <linux/smp.h> |
a2f40ccd KG |
18 | #include <linux/miscdevice.h> |
19 | #include <linux/notifier.h> | |
20 | #include <linux/watchdog.h> | |
21 | ||
22 | #include <asm/reg_booke.h> | |
23 | #include <asm/uaccess.h> | |
39cdc4bf | 24 | #include <asm/system.h> |
a2f40ccd | 25 | |
40ebbcbf | 26 | /* If the kernel parameter wdt=1, the watchdog will be enabled at boot. |
a2f40ccd KG |
27 | * Also, the wdt_period sets the watchdog timer period timeout. |
28 | * For E500 cpus the wdt_period sets which bit changing from 0->1 will | |
29 | * trigger a watchog timeout. This watchdog timeout will occur 3 times, the | |
30 | * first time nothing will happen, the second time a watchdog exception will | |
31 | * occur, and the final time the board will reset. | |
32 | */ | |
33 | ||
34 | #ifdef CONFIG_FSL_BOOKE | |
35 | #define WDT_PERIOD_DEFAULT 63 /* Ex. wdt_period=28 bus=333Mhz , reset=~40sec */ | |
36 | #else | |
f31909c0 | 37 | #define WDT_PERIOD_DEFAULT 3 /* Refer to the PPC40x and PPC4xx manuals */ |
a2f40ccd KG |
38 | #endif /* for timing information */ |
39 | ||
f172ddc6 | 40 | u32 booke_wdt_enabled; |
39cdc4bf | 41 | u32 booke_wdt_period = WDT_PERIOD_DEFAULT; |
a2f40ccd KG |
42 | |
43 | #ifdef CONFIG_FSL_BOOKE | |
44 | #define WDTP(x) ((((63-x)&0x3)<<30)|(((63-x)&0x3c)<<15)) | |
45 | #else | |
46 | #define WDTP(x) (TCR_WP(x)) | |
47 | #endif | |
48 | ||
f172ddc6 CG |
49 | static DEFINE_SPINLOCK(booke_wdt_lock); |
50 | ||
51 | static void __booke_wdt_ping(void *data) | |
f31909c0 SR |
52 | { |
53 | mtspr(SPRN_TSR, TSR_ENW|TSR_WIS); | |
54 | } | |
55 | ||
f172ddc6 CG |
56 | static void booke_wdt_ping(void) |
57 | { | |
58 | on_each_cpu(__booke_wdt_ping, NULL, 0, 0); | |
59 | } | |
60 | ||
61 | static void __booke_wdt_enable(void *data) | |
a2f40ccd KG |
62 | { |
63 | u32 val; | |
64 | ||
f31909c0 | 65 | /* clear status before enabling watchdog */ |
f172ddc6 | 66 | __booke_wdt_ping(NULL); |
a2f40ccd | 67 | val = mfspr(SPRN_TCR); |
39cdc4bf | 68 | val |= (TCR_WIE|TCR_WRC(WRC_CHIP)|WDTP(booke_wdt_period)); |
a2f40ccd KG |
69 | |
70 | mtspr(SPRN_TCR, val); | |
71 | } | |
72 | ||
f172ddc6 | 73 | static ssize_t booke_wdt_write(struct file *file, const char __user *buf, |
a2f40ccd KG |
74 | size_t count, loff_t *ppos) |
75 | { | |
76 | booke_wdt_ping(); | |
77 | return count; | |
78 | } | |
79 | ||
80 | static struct watchdog_info ident = { | |
f172ddc6 CG |
81 | .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING, |
82 | .identity = "PowerPC Book-E Watchdog", | |
a2f40ccd KG |
83 | }; |
84 | ||
f172ddc6 | 85 | static int booke_wdt_ioctl(struct inode *inode, struct file *file, |
a2f40ccd KG |
86 | unsigned int cmd, unsigned long arg) |
87 | { | |
88 | u32 tmp = 0; | |
538bacf8 | 89 | u32 __user *p = (u32 __user *)arg; |
a2f40ccd KG |
90 | |
91 | switch (cmd) { | |
92 | case WDIOC_GETSUPPORT: | |
f172ddc6 | 93 | if (copy_to_user((struct watchdog_info __user *)arg, &ident, |
a2f40ccd KG |
94 | sizeof(struct watchdog_info))) |
95 | return -EFAULT; | |
96 | case WDIOC_GETSTATUS: | |
538bacf8 | 97 | return put_user(ident.options, p); |
a2f40ccd KG |
98 | case WDIOC_GETBOOTSTATUS: |
99 | /* XXX: something is clearing TSR */ | |
100 | tmp = mfspr(SPRN_TSR) & TSR_WRS(3); | |
101 | /* returns 1 if last reset was caused by the WDT */ | |
102 | return (tmp ? 1 : 0); | |
103 | case WDIOC_KEEPALIVE: | |
104 | booke_wdt_ping(); | |
105 | return 0; | |
106 | case WDIOC_SETTIMEOUT: | |
538bacf8 | 107 | if (get_user(booke_wdt_period, p)) |
a2f40ccd | 108 | return -EFAULT; |
39cdc4bf | 109 | mtspr(SPRN_TCR, (mfspr(SPRN_TCR)&~WDTP(0))|WDTP(booke_wdt_period)); |
a2f40ccd KG |
110 | return 0; |
111 | case WDIOC_GETTIMEOUT: | |
538bacf8 | 112 | return put_user(booke_wdt_period, p); |
a2f40ccd | 113 | case WDIOC_SETOPTIONS: |
538bacf8 | 114 | if (get_user(tmp, p)) |
a2f40ccd KG |
115 | return -EINVAL; |
116 | if (tmp == WDIOS_ENABLECARD) { | |
117 | booke_wdt_ping(); | |
118 | break; | |
119 | } else | |
120 | return -EINVAL; | |
121 | return 0; | |
122 | default: | |
795b89d2 | 123 | return -ENOTTY; |
a2f40ccd KG |
124 | } |
125 | ||
126 | return 0; | |
127 | } | |
f172ddc6 CG |
128 | |
129 | static int booke_wdt_open(struct inode *inode, struct file *file) | |
a2f40ccd | 130 | { |
f172ddc6 | 131 | spin_lock(&booke_wdt_lock); |
39cdc4bf KG |
132 | if (booke_wdt_enabled == 0) { |
133 | booke_wdt_enabled = 1; | |
f172ddc6 CG |
134 | on_each_cpu(__booke_wdt_enable, NULL, 0, 0); |
135 | printk(KERN_INFO "PowerPC Book-E Watchdog Timer Enabled " | |
136 | "(wdt_period=%d)\n", booke_wdt_period); | |
a2f40ccd | 137 | } |
f172ddc6 | 138 | spin_unlock(&booke_wdt_lock); |
a2f40ccd | 139 | |
ec9505a7 | 140 | return nonseekable_open(inode, file); |
a2f40ccd KG |
141 | } |
142 | ||
62322d25 | 143 | static const struct file_operations booke_wdt_fops = { |
f172ddc6 CG |
144 | .owner = THIS_MODULE, |
145 | .llseek = no_llseek, | |
146 | .write = booke_wdt_write, | |
147 | .ioctl = booke_wdt_ioctl, | |
148 | .open = booke_wdt_open, | |
a2f40ccd KG |
149 | }; |
150 | ||
151 | static struct miscdevice booke_wdt_miscdev = { | |
f172ddc6 CG |
152 | .minor = WATCHDOG_MINOR, |
153 | .name = "watchdog", | |
154 | .fops = &booke_wdt_fops, | |
a2f40ccd KG |
155 | }; |
156 | ||
157 | static void __exit booke_wdt_exit(void) | |
158 | { | |
159 | misc_deregister(&booke_wdt_miscdev); | |
160 | } | |
161 | ||
a2f40ccd KG |
162 | static int __init booke_wdt_init(void) |
163 | { | |
164 | int ret = 0; | |
165 | ||
f172ddc6 | 166 | printk(KERN_INFO "PowerPC Book-E Watchdog Timer Loaded\n"); |
a78719c3 | 167 | ident.firmware_version = cur_cpu_spec->pvr_value; |
a2f40ccd KG |
168 | |
169 | ret = misc_register(&booke_wdt_miscdev); | |
170 | if (ret) { | |
f172ddc6 | 171 | printk(KERN_CRIT "Cannot register miscdev on minor=%d: %d\n", |
a2f40ccd KG |
172 | WATCHDOG_MINOR, ret); |
173 | return ret; | |
174 | } | |
175 | ||
f172ddc6 | 176 | spin_lock(&booke_wdt_lock); |
39cdc4bf | 177 | if (booke_wdt_enabled == 1) { |
f172ddc6 CG |
178 | printk(KERN_INFO "PowerPC Book-E Watchdog Timer Enabled " |
179 | "(wdt_period=%d)\n", booke_wdt_period); | |
180 | on_each_cpu(__booke_wdt_enable, NULL, 0, 0); | |
a2f40ccd | 181 | } |
f172ddc6 | 182 | spin_unlock(&booke_wdt_lock); |
a2f40ccd KG |
183 | |
184 | return ret; | |
185 | } | |
186 | device_initcall(booke_wdt_init); |