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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");
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 ret;
195err:
196 clk_disable_unprepare(clk);
197 clk_put(clk);
198 return ret;
199}
200
201static void __exit sa1100dog_exit(void)
202{
203 misc_deregister(&sa1100dog_miscdev);
204 clk_disable_unprepare(clk);
205 clk_put(clk);
206}
207
208module_init(sa1100dog_init);
209module_exit(sa1100dog_exit);
210
211MODULE_AUTHOR("Oleg Drokin <green@crimea.edu>");
212MODULE_DESCRIPTION("SA1100/PXA2xx Watchdog");
213
214module_param(margin, int, 0);
215MODULE_PARM_DESC(margin, "Watchdog margin in seconds (default 60s)");
216
217MODULE_LICENSE("GPL");