aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/char/watchdog/booke_wdt.c
diff options
context:
space:
mode:
authorLen Brown <len.brown@intel.com>2005-09-08 01:45:47 -0400
committerLen Brown <len.brown@intel.com>2005-09-08 01:45:47 -0400
commit64e47488c913ac704d465a6af86a26786d1412a5 (patch)
treed3b0148592963dcde26e4bb35ddfec8b1eaf8e23 /drivers/char/watchdog/booke_wdt.c
parent4a35a46bf1cda4737c428380d1db5d15e2590d18 (diff)
parentcaf39e87cc1182f7dae84eefc43ca14d54c78ef9 (diff)
Merge linux-2.6 with linux-acpi-2.6
Diffstat (limited to 'drivers/char/watchdog/booke_wdt.c')
-rw-r--r--drivers/char/watchdog/booke_wdt.c192
1 files changed, 192 insertions, 0 deletions
diff --git a/drivers/char/watchdog/booke_wdt.c b/drivers/char/watchdog/booke_wdt.c
new file mode 100644
index 000000000000..abc30cca6645
--- /dev/null
+++ b/drivers/char/watchdog/booke_wdt.c
@@ -0,0 +1,192 @@
1/*
2 * drivers/char/watchdog/booke_wdt.c
3 *
4 * Watchdog timer for PowerPC Book-E systems
5 *
6 * Author: Matthew McClintock
7 * Maintainer: Kumar Gala <kumar.gala@freescale.com>
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
17#include <linux/config.h>
18#include <linux/module.h>
19#include <linux/fs.h>
20#include <linux/miscdevice.h>
21#include <linux/notifier.h>
22#include <linux/watchdog.h>
23
24#include <asm/reg_booke.h>
25#include <asm/uaccess.h>
26#include <asm/system.h>
27
28/* If the kernel parameter wdt_enable=1, the watchdog will be enabled at boot.
29 * Also, the wdt_period sets the watchdog timer period timeout.
30 * For E500 cpus the wdt_period sets which bit changing from 0->1 will
31 * trigger a watchog timeout. This watchdog timeout will occur 3 times, the
32 * first time nothing will happen, the second time a watchdog exception will
33 * occur, and the final time the board will reset.
34 */
35
36#ifdef CONFIG_FSL_BOOKE
37#define WDT_PERIOD_DEFAULT 63 /* Ex. wdt_period=28 bus=333Mhz , reset=~40sec */
38#else
39#define WDT_PERIOD_DEFAULT 4 /* Refer to the PPC40x and PPC4xx manuals */
40#endif /* for timing information */
41
42u32 booke_wdt_enabled = 0;
43u32 booke_wdt_period = WDT_PERIOD_DEFAULT;
44
45#ifdef CONFIG_FSL_BOOKE
46#define WDTP(x) ((((63-x)&0x3)<<30)|(((63-x)&0x3c)<<15))
47#else
48#define WDTP(x) (TCR_WP(x))
49#endif
50
51/*
52 * booke_wdt_enable:
53 */
54static __inline__ void booke_wdt_enable(void)
55{
56 u32 val;
57
58 val = mfspr(SPRN_TCR);
59 val |= (TCR_WIE|TCR_WRC(WRC_CHIP)|WDTP(booke_wdt_period));
60
61 mtspr(SPRN_TCR, val);
62}
63
64/*
65 * booke_wdt_ping:
66 */
67static __inline__ void booke_wdt_ping(void)
68{
69 mtspr(SPRN_TSR, TSR_ENW|TSR_WIS);
70}
71
72/*
73 * booke_wdt_write:
74 */
75static ssize_t booke_wdt_write (struct file *file, const char *buf,
76 size_t count, loff_t *ppos)
77{
78 booke_wdt_ping();
79 return count;
80}
81
82static struct watchdog_info ident = {
83 .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
84 .firmware_version = 0,
85 .identity = "PowerPC Book-E Watchdog",
86};
87
88/*
89 * booke_wdt_ioctl:
90 */
91static int booke_wdt_ioctl (struct inode *inode, struct file *file,
92 unsigned int cmd, unsigned long arg)
93{
94 u32 tmp = 0;
95
96 switch (cmd) {
97 case WDIOC_GETSUPPORT:
98 if (copy_to_user ((struct watchdog_info *) arg, &ident,
99 sizeof(struct watchdog_info)))
100 return -EFAULT;
101 case WDIOC_GETSTATUS:
102 return put_user(ident.options, (u32 *) arg);
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:
112 if (get_user(booke_wdt_period, (u32 *) arg))
113 return -EFAULT;
114 mtspr(SPRN_TCR, (mfspr(SPRN_TCR)&~WDTP(0))|WDTP(booke_wdt_period));
115 return 0;
116 case WDIOC_GETTIMEOUT:
117 return put_user(booke_wdt_period, (u32 *) arg);
118 case WDIOC_SETOPTIONS:
119 if (get_user(tmp, (u32 *) arg))
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 */
136static int booke_wdt_open (struct inode *inode, struct file *file)
137{
138 if (booke_wdt_enabled == 0) {
139 booke_wdt_enabled = 1;
140 booke_wdt_enable();
141 printk (KERN_INFO "PowerPC Book-E Watchdog Timer Enabled (wdt_period=%d)\n",
142 booke_wdt_period);
143 }
144
145 return 0;
146}
147
148static struct file_operations booke_wdt_fops = {
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
156static struct miscdevice booke_wdt_miscdev = {
157 .minor = WATCHDOG_MINOR,
158 .name = "watchdog",
159 .fops = &booke_wdt_fops,
160};
161
162static void __exit booke_wdt_exit(void)
163{
164 misc_deregister(&booke_wdt_miscdev);
165}
166
167/*
168 * booke_wdt_init:
169 */
170static int __init booke_wdt_init(void)
171{
172 int ret = 0;
173
174 printk (KERN_INFO "PowerPC Book-E Watchdog Timer Loaded\n");
175 ident.firmware_version = cpu_specs[0].pvr_value;
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
184 if (booke_wdt_enabled == 1) {
185 printk (KERN_INFO "PowerPC Book-E Watchdog Timer Enabled (wdt_period=%d)\n",
186 booke_wdt_period);
187 booke_wdt_enable();
188 }
189
190 return ret;
191}
192device_initcall(booke_wdt_init);