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a2f40ccd KG |
1 | /* |
2 | * drivers/char/watchdog/booke_wdt.c | |
3 | * | |
4 | * Watchdog timer for PowerPC Book-E systems | |
5 | * | |
6 | * Author: Matthew McClintock | |
4c8d3d99 | 7 | * Maintainer: Kumar Gala <galak@kernel.crashing.org> |
a2f40ccd KG |
8 | * |
9 | * Copyright 2005 Freescale Semiconductor Inc. | |
10 | * | |
11 | * This program is free software; you can redistribute it and/or modify it | |
12 | * under the terms of the GNU General Public License as published by the | |
13 | * Free Software Foundation; either version 2 of the License, or (at your | |
14 | * option) any later version. | |
15 | */ | |
16 | ||
a2f40ccd KG |
17 | #include <linux/module.h> |
18 | #include <linux/fs.h> | |
19 | #include <linux/miscdevice.h> | |
20 | #include <linux/notifier.h> | |
21 | #include <linux/watchdog.h> | |
22 | ||
23 | #include <asm/reg_booke.h> | |
24 | #include <asm/uaccess.h> | |
39cdc4bf | 25 | #include <asm/system.h> |
a2f40ccd KG |
26 | |
27 | /* If the kernel parameter wdt_enable=1, the watchdog will be enabled at boot. | |
28 | * Also, the wdt_period sets the watchdog timer period timeout. | |
29 | * For E500 cpus the wdt_period sets which bit changing from 0->1 will | |
30 | * trigger a watchog timeout. This watchdog timeout will occur 3 times, the | |
31 | * first time nothing will happen, the second time a watchdog exception will | |
32 | * occur, and the final time the board will reset. | |
33 | */ | |
34 | ||
35 | #ifdef CONFIG_FSL_BOOKE | |
36 | #define WDT_PERIOD_DEFAULT 63 /* Ex. wdt_period=28 bus=333Mhz , reset=~40sec */ | |
37 | #else | |
38 | #define WDT_PERIOD_DEFAULT 4 /* Refer to the PPC40x and PPC4xx manuals */ | |
39 | #endif /* for timing information */ | |
40 | ||
39cdc4bf KG |
41 | u32 booke_wdt_enabled = 0; |
42 | u32 booke_wdt_period = WDT_PERIOD_DEFAULT; | |
a2f40ccd KG |
43 | |
44 | #ifdef CONFIG_FSL_BOOKE | |
45 | #define WDTP(x) ((((63-x)&0x3)<<30)|(((63-x)&0x3c)<<15)) | |
46 | #else | |
47 | #define WDTP(x) (TCR_WP(x)) | |
48 | #endif | |
49 | ||
50 | /* | |
51 | * booke_wdt_enable: | |
52 | */ | |
53 | static __inline__ void booke_wdt_enable(void) | |
54 | { | |
55 | u32 val; | |
56 | ||
57 | val = mfspr(SPRN_TCR); | |
39cdc4bf | 58 | val |= (TCR_WIE|TCR_WRC(WRC_CHIP)|WDTP(booke_wdt_period)); |
a2f40ccd KG |
59 | |
60 | mtspr(SPRN_TCR, val); | |
61 | } | |
62 | ||
63 | /* | |
64 | * booke_wdt_ping: | |
65 | */ | |
66 | static __inline__ void booke_wdt_ping(void) | |
67 | { | |
68 | mtspr(SPRN_TSR, TSR_ENW|TSR_WIS); | |
69 | } | |
70 | ||
71 | /* | |
72 | * booke_wdt_write: | |
73 | */ | |
538bacf8 | 74 | static ssize_t booke_wdt_write (struct file *file, const char __user *buf, |
a2f40ccd KG |
75 | size_t count, loff_t *ppos) |
76 | { | |
77 | booke_wdt_ping(); | |
78 | return count; | |
79 | } | |
80 | ||
81 | static struct watchdog_info ident = { | |
82 | .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING, | |
83 | .firmware_version = 0, | |
84 | .identity = "PowerPC Book-E Watchdog", | |
85 | }; | |
86 | ||
87 | /* | |
88 | * booke_wdt_ioctl: | |
89 | */ | |
90 | static int booke_wdt_ioctl (struct inode *inode, struct file *file, | |
91 | unsigned int cmd, unsigned long arg) | |
92 | { | |
93 | u32 tmp = 0; | |
538bacf8 | 94 | u32 __user *p = (u32 __user *)arg; |
a2f40ccd KG |
95 | |
96 | switch (cmd) { | |
97 | case WDIOC_GETSUPPORT: | |
538bacf8 | 98 | if (copy_to_user ((struct watchdog_info __user *) arg, &ident, |
a2f40ccd KG |
99 | sizeof(struct watchdog_info))) |
100 | return -EFAULT; | |
101 | case WDIOC_GETSTATUS: | |
538bacf8 | 102 | return put_user(ident.options, p); |
a2f40ccd KG |
103 | case WDIOC_GETBOOTSTATUS: |
104 | /* XXX: something is clearing TSR */ | |
105 | tmp = mfspr(SPRN_TSR) & TSR_WRS(3); | |
106 | /* returns 1 if last reset was caused by the WDT */ | |
107 | return (tmp ? 1 : 0); | |
108 | case WDIOC_KEEPALIVE: | |
109 | booke_wdt_ping(); | |
110 | return 0; | |
111 | case WDIOC_SETTIMEOUT: | |
538bacf8 | 112 | if (get_user(booke_wdt_period, p)) |
a2f40ccd | 113 | return -EFAULT; |
39cdc4bf | 114 | mtspr(SPRN_TCR, (mfspr(SPRN_TCR)&~WDTP(0))|WDTP(booke_wdt_period)); |
a2f40ccd KG |
115 | return 0; |
116 | case WDIOC_GETTIMEOUT: | |
538bacf8 | 117 | return put_user(booke_wdt_period, p); |
a2f40ccd | 118 | case WDIOC_SETOPTIONS: |
538bacf8 | 119 | if (get_user(tmp, p)) |
a2f40ccd KG |
120 | return -EINVAL; |
121 | if (tmp == WDIOS_ENABLECARD) { | |
122 | booke_wdt_ping(); | |
123 | break; | |
124 | } else | |
125 | return -EINVAL; | |
126 | return 0; | |
127 | default: | |
128 | return -ENOIOCTLCMD; | |
129 | } | |
130 | ||
131 | return 0; | |
132 | } | |
133 | /* | |
134 | * booke_wdt_open: | |
135 | */ | |
136 | static int booke_wdt_open (struct inode *inode, struct file *file) | |
137 | { | |
39cdc4bf KG |
138 | if (booke_wdt_enabled == 0) { |
139 | booke_wdt_enabled = 1; | |
a2f40ccd KG |
140 | booke_wdt_enable(); |
141 | printk (KERN_INFO "PowerPC Book-E Watchdog Timer Enabled (wdt_period=%d)\n", | |
39cdc4bf | 142 | booke_wdt_period); |
a2f40ccd KG |
143 | } |
144 | ||
145 | return 0; | |
146 | } | |
147 | ||
62322d25 | 148 | static const struct file_operations booke_wdt_fops = { |
a2f40ccd KG |
149 | .owner = THIS_MODULE, |
150 | .llseek = no_llseek, | |
151 | .write = booke_wdt_write, | |
152 | .ioctl = booke_wdt_ioctl, | |
153 | .open = booke_wdt_open, | |
154 | }; | |
155 | ||
156 | static struct miscdevice booke_wdt_miscdev = { | |
157 | .minor = WATCHDOG_MINOR, | |
158 | .name = "watchdog", | |
159 | .fops = &booke_wdt_fops, | |
160 | }; | |
161 | ||
162 | static void __exit booke_wdt_exit(void) | |
163 | { | |
164 | misc_deregister(&booke_wdt_miscdev); | |
165 | } | |
166 | ||
167 | /* | |
168 | * booke_wdt_init: | |
169 | */ | |
170 | static int __init booke_wdt_init(void) | |
171 | { | |
172 | int ret = 0; | |
173 | ||
174 | printk (KERN_INFO "PowerPC Book-E Watchdog Timer Loaded\n"); | |
a78719c3 | 175 | ident.firmware_version = cur_cpu_spec->pvr_value; |
a2f40ccd KG |
176 | |
177 | ret = misc_register(&booke_wdt_miscdev); | |
178 | if (ret) { | |
179 | printk (KERN_CRIT "Cannot register miscdev on minor=%d (err=%d)\n", | |
180 | WATCHDOG_MINOR, ret); | |
181 | return ret; | |
182 | } | |
183 | ||
39cdc4bf | 184 | if (booke_wdt_enabled == 1) { |
a2f40ccd | 185 | printk (KERN_INFO "PowerPC Book-E Watchdog Timer Enabled (wdt_period=%d)\n", |
39cdc4bf | 186 | booke_wdt_period); |
a2f40ccd KG |
187 | booke_wdt_enable(); |
188 | } | |
189 | ||
190 | return ret; | |
191 | } | |
192 | device_initcall(booke_wdt_init); |