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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// SPDX-License-Identifier: GPL-2.0+
2/*
3 * Watchdog driver for the SA11x0/PXA2xx
4 *
5 * (c) Copyright 2000 Oleg Drokin <green@crimea.edu>
6 * Based on SoftDog driver by Alan Cox <alan@lxorguk.ukuu.org.uk>
7 *
8 * Neither Oleg Drokin nor iXcelerator.com admit liability nor provide
9 * warranty for any of this software. This material is provided
10 * "AS-IS" and at no charge.
11 *
12 * (c) Copyright 2000 Oleg Drokin <green@crimea.edu>
13 *
14 * 27/11/2000 Initial release
15 */
16
17#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
18
19#include <linux/module.h>
20#include <linux/moduleparam.h>
21#include <linux/clk.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/io.h>
29#include <linux/bitops.h>
30#include <linux/uaccess.h>
31#include <linux/timex.h>
32
33#ifdef CONFIG_ARCH_PXA
34#include <mach/regs-ost.h>
35#endif
36
37#include <mach/reset.h>
38#include <mach/hardware.h>
39
40static unsigned long oscr_freq;
41static unsigned long sa1100wdt_users;
42static unsigned int pre_margin;
43static int boot_status;
44
45/*
46 * Allow only one person to hold it open
47 */
48static int sa1100dog_open(struct inode *inode, struct file *file)
49{
50 if (test_and_set_bit(1, &sa1100wdt_users))
51 return -EBUSY;
52
53 /* Activate SA1100 Watchdog timer */
54 writel_relaxed(readl_relaxed(OSCR) + pre_margin, OSMR3);
55 writel_relaxed(OSSR_M3, OSSR);
56 writel_relaxed(OWER_WME, OWER);
57 writel_relaxed(readl_relaxed(OIER) | OIER_E3, OIER);
58 return stream_open(inode, file);
59}
60
61/*
62 * The watchdog cannot be disabled.
63 *
64 * Previous comments suggested that turning off the interrupt by
65 * clearing OIER[E3] would prevent the watchdog timing out but this
66 * does not appear to be true (at least on the PXA255).
67 */
68static int sa1100dog_release(struct inode *inode, struct file *file)
69{
70 pr_crit("Device closed - timer will not stop\n");
71 clear_bit(1, &sa1100wdt_users);
72 return 0;
73}
74
75static ssize_t sa1100dog_write(struct file *file, const char __user *data,
76 size_t len, loff_t *ppos)
77{
78 if (len)
79 /* Refresh OSMR3 timer. */
80 writel_relaxed(readl_relaxed(OSCR) + pre_margin, OSMR3);
81 return len;
82}
83
84static const struct watchdog_info ident = {
85 .options = WDIOF_CARDRESET | WDIOF_SETTIMEOUT
86 | WDIOF_KEEPALIVEPING,
87 .identity = "SA1100/PXA255 Watchdog",
88 .firmware_version = 1,
89};
90
91static long sa1100dog_ioctl(struct file *file, unsigned int cmd,
92 unsigned long arg)
93{
94 int ret = -ENOTTY;
95 int time;
96 void __user *argp = (void __user *)arg;
97 int __user *p = argp;
98
99 switch (cmd) {
100 case WDIOC_GETSUPPORT:
101 ret = copy_to_user(argp, &ident,
102 sizeof(ident)) ? -EFAULT : 0;
103 break;
104
105 case WDIOC_GETSTATUS:
106 ret = put_user(0, p);
107 break;
108
109 case WDIOC_GETBOOTSTATUS:
110 ret = put_user(boot_status, p);
111 break;
112
113 case WDIOC_KEEPALIVE:
114 writel_relaxed(readl_relaxed(OSCR) + pre_margin, OSMR3);
115 ret = 0;
116 break;
117
118 case WDIOC_SETTIMEOUT:
119 ret = get_user(time, p);
120 if (ret)
121 break;
122
123 if (time <= 0 || (oscr_freq * (long long)time >= 0xffffffff)) {
124 ret = -EINVAL;
125 break;
126 }
127
128 pre_margin = oscr_freq * time;
129 writel_relaxed(readl_relaxed(OSCR) + pre_margin, OSMR3);
130 fallthrough;
131
132 case WDIOC_GETTIMEOUT:
133 ret = put_user(pre_margin / oscr_freq, p);
134 break;
135 }
136 return ret;
137}
138
139static const struct file_operations sa1100dog_fops = {
140 .owner = THIS_MODULE,
141 .llseek = no_llseek,
142 .write = sa1100dog_write,
143 .unlocked_ioctl = sa1100dog_ioctl,
144 .compat_ioctl = compat_ptr_ioctl,
145 .open = sa1100dog_open,
146 .release = sa1100dog_release,
147};
148
149static struct miscdevice sa1100dog_miscdev = {
150 .minor = WATCHDOG_MINOR,
151 .name = "watchdog",
152 .fops = &sa1100dog_fops,
153};
154
155static int margin __initdata = 60; /* (secs) Default is 1 minute */
156static struct clk *clk;
157
158static int __init sa1100dog_init(void)
159{
160 int ret;
161
162 clk = clk_get(NULL, "OSTIMER0");
163 if (IS_ERR(clk)) {
164 pr_err("SA1100/PXA2xx Watchdog Timer: clock not found: %d\n",
165 (int) PTR_ERR(clk));
166 return PTR_ERR(clk);
167 }
168
169 ret = clk_prepare_enable(clk);
170 if (ret) {
171 pr_err("SA1100/PXA2xx Watchdog Timer: clock failed to prepare+enable: %d\n",
172 ret);
173 goto err;
174 }
175
176 oscr_freq = clk_get_rate(clk);
177
178 /*
179 * Read the reset status, and save it for later. If
180 * we suspend, RCSR will be cleared, and the watchdog
181 * reset reason will be lost.
182 */
183 boot_status = (reset_status & RESET_STATUS_WATCHDOG) ?
184 WDIOF_CARDRESET : 0;
185 pre_margin = oscr_freq * margin;
186
187 ret = misc_register(&sa1100dog_miscdev);
188 if (ret == 0) {
189 pr_info("SA1100/PXA2xx Watchdog Timer: timer margin %d sec\n",
190 margin);
191 return 0;
192 }
193
194 clk_disable_unprepare(clk);
195err:
196 clk_put(clk);
197 return ret;
198}
199
200static void __exit sa1100dog_exit(void)
201{
202 misc_deregister(&sa1100dog_miscdev);
203 clk_disable_unprepare(clk);
204 clk_put(clk);
205}
206
207module_init(sa1100dog_init);
208module_exit(sa1100dog_exit);
209
210MODULE_AUTHOR("Oleg Drokin <green@crimea.edu>");
211MODULE_DESCRIPTION("SA1100/PXA2xx Watchdog");
212
213module_param(margin, int, 0);
214MODULE_PARM_DESC(margin, "Watchdog margin in seconds (default 60s)");
215
216MODULE_LICENSE("GPL");