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1/*
2 * Watchdog driver for the SA11x0/PXA2xx
3 *
4 * (c) Copyright 2000 Oleg Drokin <green@crimea.edu>
5 * Based on SoftDog driver by Alan Cox <alan@lxorguk.ukuu.org.uk>
6 *
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License
9 * as published by the Free Software Foundation; either version
10 * 2 of the License, or (at your option) any later version.
11 *
12 * Neither Oleg Drokin nor iXcelerator.com admit liability nor provide
13 * warranty for any of this software. This material is provided
14 * "AS-IS" and at no charge.
15 *
16 * (c) Copyright 2000 Oleg Drokin <green@crimea.edu>
17 *
18 * 27/11/2000 Initial release
19 */
20#include <linux/module.h>
21#include <linux/moduleparam.h>
22#include <linux/types.h>
23#include <linux/kernel.h>
24#include <linux/fs.h>
25#include <linux/miscdevice.h>
26#include <linux/watchdog.h>
27#include <linux/init.h>
28#include <linux/bitops.h>
29#include <linux/uaccess.h>
30#include <linux/timex.h>
31
32#ifdef CONFIG_ARCH_PXA
33#include <mach/regs-ost.h>
34#endif
35
36#include <mach/reset.h>
37#include <mach/hardware.h>
38
39static unsigned long oscr_freq;
40static unsigned long sa1100wdt_users;
41static unsigned int pre_margin;
42static int boot_status;
43
44/*
45 * Allow only one person to hold it open
46 */
47static int sa1100dog_open(struct inode *inode, struct file *file)
48{
49 if (test_and_set_bit(1, &sa1100wdt_users))
50 return -EBUSY;
51
52 /* Activate SA1100 Watchdog timer */
53 OSMR3 = OSCR + pre_margin;
54 OSSR = OSSR_M3;
55 OWER = OWER_WME;
56 OIER |= OIER_E3;
57 return nonseekable_open(inode, file);
58}
59
60/*
61 * The watchdog cannot be disabled.
62 *
63 * Previous comments suggested that turning off the interrupt by
64 * clearing OIER[E3] would prevent the watchdog timing out but this
65 * does not appear to be true (at least on the PXA255).
66 */
67static int sa1100dog_release(struct inode *inode, struct file *file)
68{
69 printk(KERN_CRIT "WATCHDOG: Device closed - timer will not stop\n");
70 clear_bit(1, &sa1100wdt_users);
71 return 0;
72}
73
74static ssize_t sa1100dog_write(struct file *file, const char __user *data,
75 size_t len, loff_t *ppos)
76{
77 if (len)
78 /* Refresh OSMR3 timer. */
79 OSMR3 = OSCR + pre_margin;
80 return len;
81}
82
83static const struct watchdog_info ident = {
84 .options = WDIOF_CARDRESET | WDIOF_SETTIMEOUT
85 | WDIOF_KEEPALIVEPING,
86 .identity = "SA1100/PXA255 Watchdog",
87 .firmware_version = 1,
88};
89
90static long sa1100dog_ioctl(struct file *file, unsigned int cmd,
91 unsigned long arg)
92{
93 int ret = -ENOTTY;
94 int time;
95 void __user *argp = (void __user *)arg;
96 int __user *p = argp;
97
98 switch (cmd) {
99 case WDIOC_GETSUPPORT:
100 ret = copy_to_user(argp, &ident,
101 sizeof(ident)) ? -EFAULT : 0;
102 break;
103
104 case WDIOC_GETSTATUS:
105 ret = put_user(0, p);
106 break;
107
108 case WDIOC_GETBOOTSTATUS:
109 ret = put_user(boot_status, p);
110 break;
111
112 case WDIOC_KEEPALIVE:
113 OSMR3 = OSCR + pre_margin;
114 ret = 0;
115 break;
116
117 case WDIOC_SETTIMEOUT:
118 ret = get_user(time, p);
119 if (ret)
120 break;
121
122 if (time <= 0 || (oscr_freq * (long long)time >= 0xffffffff)) {
123 ret = -EINVAL;
124 break;
125 }
126
127 pre_margin = oscr_freq * time;
128 OSMR3 = OSCR + pre_margin;
129 /*fall through*/
130
131 case WDIOC_GETTIMEOUT:
132 ret = put_user(pre_margin / oscr_freq, p);
133 break;
134 }
135 return ret;
136}
137
138static const struct file_operations sa1100dog_fops = {
139 .owner = THIS_MODULE,
140 .llseek = no_llseek,
141 .write = sa1100dog_write,
142 .unlocked_ioctl = sa1100dog_ioctl,
143 .open = sa1100dog_open,
144 .release = sa1100dog_release,
145};
146
147static struct miscdevice sa1100dog_miscdev = {
148 .minor = WATCHDOG_MINOR,
149 .name = "watchdog",
150 .fops = &sa1100dog_fops,
151};
152
153static int margin __initdata = 60; /* (secs) Default is 1 minute */
154
155static int __init sa1100dog_init(void)
156{
157 int ret;
158
159 oscr_freq = get_clock_tick_rate();
160
161 /*
162 * Read the reset status, and save it for later. If
163 * we suspend, RCSR will be cleared, and the watchdog
164 * reset reason will be lost.
165 */
166 boot_status = (reset_status & RESET_STATUS_WATCHDOG) ?
167 WDIOF_CARDRESET : 0;
168 pre_margin = oscr_freq * margin;
169
170 ret = misc_register(&sa1100dog_miscdev);
171 if (ret == 0)
172 printk(KERN_INFO
173 "SA1100/PXA2xx Watchdog Timer: timer margin %d sec\n",
174 margin);
175 return ret;
176}
177
178static void __exit sa1100dog_exit(void)
179{
180 misc_deregister(&sa1100dog_miscdev);
181}
182
183module_init(sa1100dog_init);
184module_exit(sa1100dog_exit);
185
186MODULE_AUTHOR("Oleg Drokin <green@crimea.edu>");
187MODULE_DESCRIPTION("SA1100/PXA2xx Watchdog");
188
189module_param(margin, int, 0);
190MODULE_PARM_DESC(margin, "Watchdog margin in seconds (default 60s)");
191
192MODULE_LICENSE("GPL");
193MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
1/*
2 * Watchdog driver for the SA11x0/PXA2xx
3 *
4 * (c) Copyright 2000 Oleg Drokin <green@crimea.edu>
5 * Based on SoftDog driver by Alan Cox <alan@lxorguk.ukuu.org.uk>
6 *
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License
9 * as published by the Free Software Foundation; either version
10 * 2 of the License, or (at your option) any later version.
11 *
12 * Neither Oleg Drokin nor iXcelerator.com admit liability nor provide
13 * warranty for any of this software. This material is provided
14 * "AS-IS" and at no charge.
15 *
16 * (c) Copyright 2000 Oleg Drokin <green@crimea.edu>
17 *
18 * 27/11/2000 Initial release
19 */
20
21#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
22
23#include <linux/module.h>
24#include <linux/moduleparam.h>
25#include <linux/clk.h>
26#include <linux/types.h>
27#include <linux/kernel.h>
28#include <linux/fs.h>
29#include <linux/miscdevice.h>
30#include <linux/watchdog.h>
31#include <linux/init.h>
32#include <linux/io.h>
33#include <linux/bitops.h>
34#include <linux/uaccess.h>
35#include <linux/timex.h>
36
37#ifdef CONFIG_ARCH_PXA
38#include <mach/regs-ost.h>
39#endif
40
41#include <mach/reset.h>
42#include <mach/hardware.h>
43
44static unsigned long oscr_freq;
45static unsigned long sa1100wdt_users;
46static unsigned int pre_margin;
47static int boot_status;
48
49/*
50 * Allow only one person to hold it open
51 */
52static int sa1100dog_open(struct inode *inode, struct file *file)
53{
54 if (test_and_set_bit(1, &sa1100wdt_users))
55 return -EBUSY;
56
57 /* Activate SA1100 Watchdog timer */
58 writel_relaxed(readl_relaxed(OSCR) + pre_margin, OSMR3);
59 writel_relaxed(OSSR_M3, OSSR);
60 writel_relaxed(OWER_WME, OWER);
61 writel_relaxed(readl_relaxed(OIER) | OIER_E3, OIER);
62 return nonseekable_open(inode, file);
63}
64
65/*
66 * The watchdog cannot be disabled.
67 *
68 * Previous comments suggested that turning off the interrupt by
69 * clearing OIER[E3] would prevent the watchdog timing out but this
70 * does not appear to be true (at least on the PXA255).
71 */
72static int sa1100dog_release(struct inode *inode, struct file *file)
73{
74 pr_crit("Device closed - timer will not stop\n");
75 clear_bit(1, &sa1100wdt_users);
76 return 0;
77}
78
79static ssize_t sa1100dog_write(struct file *file, const char __user *data,
80 size_t len, loff_t *ppos)
81{
82 if (len)
83 /* Refresh OSMR3 timer. */
84 writel_relaxed(readl_relaxed(OSCR) + pre_margin, OSMR3);
85 return len;
86}
87
88static const struct watchdog_info ident = {
89 .options = WDIOF_CARDRESET | WDIOF_SETTIMEOUT
90 | WDIOF_KEEPALIVEPING,
91 .identity = "SA1100/PXA255 Watchdog",
92 .firmware_version = 1,
93};
94
95static long sa1100dog_ioctl(struct file *file, unsigned int cmd,
96 unsigned long arg)
97{
98 int ret = -ENOTTY;
99 int time;
100 void __user *argp = (void __user *)arg;
101 int __user *p = argp;
102
103 switch (cmd) {
104 case WDIOC_GETSUPPORT:
105 ret = copy_to_user(argp, &ident,
106 sizeof(ident)) ? -EFAULT : 0;
107 break;
108
109 case WDIOC_GETSTATUS:
110 ret = put_user(0, p);
111 break;
112
113 case WDIOC_GETBOOTSTATUS:
114 ret = put_user(boot_status, p);
115 break;
116
117 case WDIOC_KEEPALIVE:
118 writel_relaxed(readl_relaxed(OSCR) + pre_margin, OSMR3);
119 ret = 0;
120 break;
121
122 case WDIOC_SETTIMEOUT:
123 ret = get_user(time, p);
124 if (ret)
125 break;
126
127 if (time <= 0 || (oscr_freq * (long long)time >= 0xffffffff)) {
128 ret = -EINVAL;
129 break;
130 }
131
132 pre_margin = oscr_freq * time;
133 writel_relaxed(readl_relaxed(OSCR) + pre_margin, OSMR3);
134 /*fall through*/
135
136 case WDIOC_GETTIMEOUT:
137 ret = put_user(pre_margin / oscr_freq, p);
138 break;
139 }
140 return ret;
141}
142
143static const struct file_operations sa1100dog_fops = {
144 .owner = THIS_MODULE,
145 .llseek = no_llseek,
146 .write = sa1100dog_write,
147 .unlocked_ioctl = sa1100dog_ioctl,
148 .open = sa1100dog_open,
149 .release = sa1100dog_release,
150};
151
152static struct miscdevice sa1100dog_miscdev = {
153 .minor = WATCHDOG_MINOR,
154 .name = "watchdog",
155 .fops = &sa1100dog_fops,
156};
157
158static int margin __initdata = 60; /* (secs) Default is 1 minute */
159static struct clk *clk;
160
161static int __init sa1100dog_init(void)
162{
163 int ret;
164
165 clk = clk_get(NULL, "OSTIMER0");
166 if (IS_ERR(clk)) {
167 pr_err("SA1100/PXA2xx Watchdog Timer: clock not found: %d\n",
168 (int) PTR_ERR(clk));
169 return PTR_ERR(clk);
170 }
171
172 ret = clk_prepare_enable(clk);
173 if (ret) {
174 pr_err("SA1100/PXA2xx Watchdog Timer: clock failed to prepare+enable: %d\n",
175 ret);
176 goto err;
177 }
178
179 oscr_freq = clk_get_rate(clk);
180
181 /*
182 * Read the reset status, and save it for later. If
183 * we suspend, RCSR will be cleared, and the watchdog
184 * reset reason will be lost.
185 */
186 boot_status = (reset_status & RESET_STATUS_WATCHDOG) ?
187 WDIOF_CARDRESET : 0;
188 pre_margin = oscr_freq * margin;
189
190 ret = misc_register(&sa1100dog_miscdev);
191 if (ret == 0) {
192 pr_info("SA1100/PXA2xx Watchdog Timer: timer margin %d sec\n",
193 margin);
194 return 0;
195 }
196
197 clk_disable_unprepare(clk);
198err:
199 clk_put(clk);
200 return ret;
201}
202
203static void __exit sa1100dog_exit(void)
204{
205 misc_deregister(&sa1100dog_miscdev);
206 clk_disable_unprepare(clk);
207 clk_put(clk);
208}
209
210module_init(sa1100dog_init);
211module_exit(sa1100dog_exit);
212
213MODULE_AUTHOR("Oleg Drokin <green@crimea.edu>");
214MODULE_DESCRIPTION("SA1100/PXA2xx Watchdog");
215
216module_param(margin, int, 0);
217MODULE_PARM_DESC(margin, "Watchdog margin in seconds (default 60s)");
218
219MODULE_LICENSE("GPL");