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15#include <linux/module.h>
16#include <linux/fs.h>
17#include <linux/smp.h>
18#include <linux/miscdevice.h>
19#include <linux/notifier.h>
20#include <linux/watchdog.h>
21#include <linux/uaccess.h>
22
23#include <asm/reg_booke.h>
24#include <asm/system.h>
25#include <asm/time.h>
26#include <asm/div64.h>
27
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35
36#ifdef CONFIG_FSL_BOOKE
37#define WDT_PERIOD_DEFAULT 38
38#else
39#define WDT_PERIOD_DEFAULT 3
40#endif
41
42u32 booke_wdt_enabled;
43u32 booke_wdt_period = WDT_PERIOD_DEFAULT;
44
45#ifdef CONFIG_FSL_BOOKE
46#define WDTP(x) ((((x)&0x3)<<30)|(((x)&0x3c)<<15))
47#define WDTP_MASK (WDTP(0))
48#else
49#define WDTP(x) (TCR_WP(x))
50#define WDTP_MASK (TCR_WP_MASK)
51#endif
52
53static DEFINE_SPINLOCK(booke_wdt_lock);
54
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63
64
65static unsigned long long period_to_sec(unsigned int period)
66{
67 unsigned long long tmp = 1ULL << (64 - period);
68 unsigned long tmp2 = ppc_tb_freq;
69
70
71
72
73 tmp2 = tmp2 / 5 * 2;
74
75 do_div(tmp, tmp2);
76 return tmp;
77}
78
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81
82
83
84static unsigned int sec_to_period(unsigned int secs)
85{
86 unsigned int period;
87 for (period = 63; period > 0; period--) {
88 if (period_to_sec(period) >= secs)
89 return period;
90 }
91 return 0;
92}
93
94static void __booke_wdt_ping(void *data)
95{
96 mtspr(SPRN_TSR, TSR_ENW|TSR_WIS);
97}
98
99static void booke_wdt_ping(void)
100{
101 on_each_cpu(__booke_wdt_ping, NULL, 0);
102}
103
104static void __booke_wdt_enable(void *data)
105{
106 u32 val;
107
108
109 __booke_wdt_ping(NULL);
110 val = mfspr(SPRN_TCR);
111 val &= ~WDTP_MASK;
112 val |= (TCR_WIE|TCR_WRC(WRC_CHIP)|WDTP(booke_wdt_period));
113
114 mtspr(SPRN_TCR, val);
115}
116
117static ssize_t booke_wdt_write(struct file *file, const char __user *buf,
118 size_t count, loff_t *ppos)
119{
120 booke_wdt_ping();
121 return count;
122}
123
124static struct watchdog_info ident = {
125 .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
126 .identity = "PowerPC Book-E Watchdog",
127};
128
129static long booke_wdt_ioctl(struct file *file,
130 unsigned int cmd, unsigned long arg)
131{
132 u32 tmp = 0;
133 u32 __user *p = (u32 __user *)arg;
134
135 switch (cmd) {
136 case WDIOC_GETSUPPORT:
137 if (copy_to_user((void *)arg, &ident, sizeof(ident)))
138 return -EFAULT;
139 case WDIOC_GETSTATUS:
140 return put_user(ident.options, p);
141 case WDIOC_GETBOOTSTATUS:
142
143 tmp = mfspr(SPRN_TSR) & TSR_WRS(3);
144
145 return (tmp ? 1 : 0);
146 case WDIOC_SETOPTIONS:
147 if (get_user(tmp, p))
148 return -EINVAL;
149 if (tmp == WDIOS_ENABLECARD) {
150 booke_wdt_ping();
151 break;
152 } else
153 return -EINVAL;
154 return 0;
155 case WDIOC_KEEPALIVE:
156 booke_wdt_ping();
157 return 0;
158 case WDIOC_SETTIMEOUT:
159 if (get_user(tmp, p))
160 return -EFAULT;
161#ifdef CONFIG_FSL_BOOKE
162
163 if (tmp > period_to_sec(1))
164 return -EINVAL;
165 booke_wdt_period = sec_to_period(tmp);
166#else
167 booke_wdt_period = tmp;
168#endif
169 mtspr(SPRN_TCR, (mfspr(SPRN_TCR) & ~WDTP_MASK) |
170 WDTP(booke_wdt_period));
171 return 0;
172 case WDIOC_GETTIMEOUT:
173 return put_user(booke_wdt_period, p);
174 default:
175 return -ENOTTY;
176 }
177
178 return 0;
179}
180
181static int booke_wdt_open(struct inode *inode, struct file *file)
182{
183 spin_lock(&booke_wdt_lock);
184 if (booke_wdt_enabled == 0) {
185 booke_wdt_enabled = 1;
186 on_each_cpu(__booke_wdt_enable, NULL, 0);
187 printk(KERN_INFO
188 "PowerPC Book-E Watchdog Timer Enabled (wdt_period=%d)\n",
189 booke_wdt_period);
190 }
191 spin_unlock(&booke_wdt_lock);
192
193 return nonseekable_open(inode, file);
194}
195
196static const struct file_operations booke_wdt_fops = {
197 .owner = THIS_MODULE,
198 .llseek = no_llseek,
199 .write = booke_wdt_write,
200 .unlocked_ioctl = booke_wdt_ioctl,
201 .open = booke_wdt_open,
202};
203
204static struct miscdevice booke_wdt_miscdev = {
205 .minor = WATCHDOG_MINOR,
206 .name = "watchdog",
207 .fops = &booke_wdt_fops,
208};
209
210static void __exit booke_wdt_exit(void)
211{
212 misc_deregister(&booke_wdt_miscdev);
213}
214
215static int __init booke_wdt_init(void)
216{
217 int ret = 0;
218
219 printk(KERN_INFO "PowerPC Book-E Watchdog Timer Loaded\n");
220 ident.firmware_version = cur_cpu_spec->pvr_value;
221
222 ret = misc_register(&booke_wdt_miscdev);
223 if (ret) {
224 printk(KERN_CRIT "Cannot register miscdev on minor=%d: %d\n",
225 WATCHDOG_MINOR, ret);
226 return ret;
227 }
228
229 spin_lock(&booke_wdt_lock);
230 if (booke_wdt_enabled == 1) {
231 printk(KERN_INFO
232 "PowerPC Book-E Watchdog Timer Enabled (wdt_period=%d)\n",
233 booke_wdt_period);
234 on_each_cpu(__booke_wdt_enable, NULL, 0);
235 }
236 spin_unlock(&booke_wdt_lock);
237
238 return ret;
239}
240device_initcall(booke_wdt_init);
241