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2e62c498 | 1 | // SPDX-License-Identifier: GPL-2.0+ |
04bf3b4f FF |
2 | /* |
3 | * Driver for the MTX-1 Watchdog. | |
4 | * | |
ed78c2da AC |
5 | * (C) Copyright 2005 4G Systems <info@4g-systems.biz>, |
6 | * All Rights Reserved. | |
04bf3b4f FF |
7 | * http://www.4g-systems.biz |
8 | * | |
143a2e54 | 9 | * (C) Copyright 2007 OpenWrt.org, Florian Fainelli <florian@openwrt.org> |
04bf3b4f FF |
10 | * (c) Copyright 2005 4G Systems <info@4g-systems.biz> |
11 | * | |
12 | * Release 0.01. | |
13 | * Author: Michael Stickel michael.stickel@4g-systems.biz | |
14 | * | |
15 | * Release 0.02. | |
16 | * Author: Florian Fainelli florian@openwrt.org | |
17 | * use the Linux watchdog/timer APIs | |
18 | * | |
19 | * The Watchdog is configured to reset the MTX-1 | |
20 | * if it is not triggered for 100 seconds. | |
21 | * It should not be triggered more often than 1.6 seconds. | |
22 | * | |
23 | * A timer triggers the watchdog every 5 seconds, until | |
24 | * it is opened for the first time. After the first open | |
25 | * it MUST be triggered every 2..95 seconds. | |
26 | */ | |
27 | ||
28 | #include <linux/module.h> | |
29 | #include <linux/moduleparam.h> | |
30 | #include <linux/types.h> | |
31 | #include <linux/errno.h> | |
32 | #include <linux/miscdevice.h> | |
33 | #include <linux/fs.h> | |
04bf3b4f FF |
34 | #include <linux/ioport.h> |
35 | #include <linux/timer.h> | |
36 | #include <linux/completion.h> | |
37 | #include <linux/jiffies.h> | |
38 | #include <linux/watchdog.h> | |
6ea8115b | 39 | #include <linux/platform_device.h> |
ed78c2da AC |
40 | #include <linux/io.h> |
41 | #include <linux/uaccess.h> | |
d2b911db | 42 | #include <linux/gpio/consumer.h> |
04bf3b4f FF |
43 | |
44 | #include <asm/mach-au1x00/au1000.h> | |
45 | ||
46 | #define MTX1_WDT_INTERVAL (5 * HZ) | |
47 | ||
48 | static int ticks = 100 * HZ; | |
49 | ||
50 | static struct { | |
51 | struct completion stop; | |
ed78c2da | 52 | spinlock_t lock; |
996d62d4 | 53 | int running; |
04bf3b4f | 54 | struct timer_list timer; |
996d62d4 | 55 | int queue; |
04bf3b4f FF |
56 | int default_ticks; |
57 | unsigned long inuse; | |
d2b911db | 58 | struct gpio_desc *gpiod; |
2ea4e76e | 59 | unsigned int gstate; |
04bf3b4f FF |
60 | } mtx1_wdt_device; |
61 | ||
e99e88a9 | 62 | static void mtx1_wdt_trigger(struct timer_list *unused) |
04bf3b4f | 63 | { |
ed78c2da | 64 | spin_lock(&mtx1_wdt_device.lock); |
04bf3b4f FF |
65 | if (mtx1_wdt_device.running) |
66 | ticks--; | |
b7f720d6 ML |
67 | |
68 | /* toggle wdt gpio */ | |
2ea4e76e | 69 | mtx1_wdt_device.gstate = !mtx1_wdt_device.gstate; |
d2b911db | 70 | gpiod_set_value(mtx1_wdt_device.gpiod, mtx1_wdt_device.gstate); |
04bf3b4f FF |
71 | |
72 | if (mtx1_wdt_device.queue && ticks) | |
73 | mod_timer(&mtx1_wdt_device.timer, jiffies + MTX1_WDT_INTERVAL); | |
ed78c2da | 74 | else |
04bf3b4f | 75 | complete(&mtx1_wdt_device.stop); |
ed78c2da | 76 | spin_unlock(&mtx1_wdt_device.lock); |
04bf3b4f FF |
77 | } |
78 | ||
79 | static void mtx1_wdt_reset(void) | |
80 | { | |
81 | ticks = mtx1_wdt_device.default_ticks; | |
82 | } | |
83 | ||
84 | ||
85 | static void mtx1_wdt_start(void) | |
86 | { | |
f80e919b FF |
87 | unsigned long flags; |
88 | ||
ed78c2da | 89 | spin_lock_irqsave(&mtx1_wdt_device.lock, flags); |
04bf3b4f FF |
90 | if (!mtx1_wdt_device.queue) { |
91 | mtx1_wdt_device.queue = 1; | |
b7f720d6 | 92 | mtx1_wdt_device.gstate = 1; |
d2b911db | 93 | gpiod_set_value(mtx1_wdt_device.gpiod, 1); |
04bf3b4f FF |
94 | mod_timer(&mtx1_wdt_device.timer, jiffies + MTX1_WDT_INTERVAL); |
95 | } | |
96 | mtx1_wdt_device.running++; | |
ed78c2da | 97 | spin_unlock_irqrestore(&mtx1_wdt_device.lock, flags); |
04bf3b4f FF |
98 | } |
99 | ||
100 | static int mtx1_wdt_stop(void) | |
101 | { | |
f80e919b FF |
102 | unsigned long flags; |
103 | ||
ed78c2da | 104 | spin_lock_irqsave(&mtx1_wdt_device.lock, flags); |
04bf3b4f FF |
105 | if (mtx1_wdt_device.queue) { |
106 | mtx1_wdt_device.queue = 0; | |
b7f720d6 | 107 | mtx1_wdt_device.gstate = 0; |
d2b911db | 108 | gpiod_set_value(mtx1_wdt_device.gpiod, 0); |
04bf3b4f | 109 | } |
04bf3b4f | 110 | ticks = mtx1_wdt_device.default_ticks; |
ed78c2da | 111 | spin_unlock_irqrestore(&mtx1_wdt_device.lock, flags); |
04bf3b4f FF |
112 | return 0; |
113 | } | |
114 | ||
115 | /* Filesystem functions */ | |
116 | ||
117 | static int mtx1_wdt_open(struct inode *inode, struct file *file) | |
118 | { | |
119 | if (test_and_set_bit(0, &mtx1_wdt_device.inuse)) | |
120 | return -EBUSY; | |
c5bf68fe | 121 | return stream_open(inode, file); |
04bf3b4f FF |
122 | } |
123 | ||
124 | ||
125 | static int mtx1_wdt_release(struct inode *inode, struct file *file) | |
126 | { | |
127 | clear_bit(0, &mtx1_wdt_device.inuse); | |
128 | return 0; | |
129 | } | |
130 | ||
ed78c2da AC |
131 | static long mtx1_wdt_ioctl(struct file *file, unsigned int cmd, |
132 | unsigned long arg) | |
04bf3b4f FF |
133 | { |
134 | void __user *argp = (void __user *)arg; | |
ed78c2da | 135 | int __user *p = (int __user *)argp; |
04bf3b4f | 136 | unsigned int value; |
ed78c2da | 137 | static const struct watchdog_info ident = { |
04bf3b4f FF |
138 | .options = WDIOF_CARDRESET, |
139 | .identity = "MTX-1 WDT", | |
140 | }; | |
141 | ||
ed78c2da | 142 | switch (cmd) { |
0c06090c WVS |
143 | case WDIOC_GETSUPPORT: |
144 | if (copy_to_user(argp, &ident, sizeof(ident))) | |
145 | return -EFAULT; | |
ed78c2da AC |
146 | break; |
147 | case WDIOC_GETSTATUS: | |
148 | case WDIOC_GETBOOTSTATUS: | |
149 | put_user(0, p); | |
150 | break; | |
ed78c2da AC |
151 | case WDIOC_SETOPTIONS: |
152 | if (get_user(value, p)) | |
153 | return -EFAULT; | |
154 | if (value & WDIOS_ENABLECARD) | |
155 | mtx1_wdt_start(); | |
156 | else if (value & WDIOS_DISABLECARD) | |
157 | mtx1_wdt_stop(); | |
158 | else | |
159 | return -EINVAL; | |
160 | return 0; | |
0c06090c WVS |
161 | case WDIOC_KEEPALIVE: |
162 | mtx1_wdt_reset(); | |
163 | break; | |
ed78c2da AC |
164 | default: |
165 | return -ENOTTY; | |
04bf3b4f FF |
166 | } |
167 | return 0; | |
168 | } | |
169 | ||
170 | ||
ed78c2da AC |
171 | static ssize_t mtx1_wdt_write(struct file *file, const char *buf, |
172 | size_t count, loff_t *ppos) | |
04bf3b4f FF |
173 | { |
174 | if (!count) | |
175 | return -EIO; | |
04bf3b4f FF |
176 | mtx1_wdt_reset(); |
177 | return count; | |
178 | } | |
179 | ||
b47a166e | 180 | static const struct file_operations mtx1_wdt_fops = { |
5f3b2756 | 181 | .owner = THIS_MODULE, |
04bf3b4f | 182 | .llseek = no_llseek, |
ed78c2da | 183 | .unlocked_ioctl = mtx1_wdt_ioctl, |
b6dfb247 | 184 | .compat_ioctl = compat_ptr_ioctl, |
5f3b2756 WVS |
185 | .open = mtx1_wdt_open, |
186 | .write = mtx1_wdt_write, | |
187 | .release = mtx1_wdt_release, | |
04bf3b4f FF |
188 | }; |
189 | ||
190 | ||
191 | static struct miscdevice mtx1_wdt_misc = { | |
5f3b2756 WVS |
192 | .minor = WATCHDOG_MINOR, |
193 | .name = "watchdog", | |
194 | .fops = &mtx1_wdt_fops, | |
04bf3b4f FF |
195 | }; |
196 | ||
197 | ||
2d991a16 | 198 | static int mtx1_wdt_probe(struct platform_device *pdev) |
04bf3b4f FF |
199 | { |
200 | int ret; | |
201 | ||
d2b911db LW |
202 | mtx1_wdt_device.gpiod = devm_gpiod_get(&pdev->dev, |
203 | NULL, GPIOD_OUT_HIGH); | |
204 | if (IS_ERR(mtx1_wdt_device.gpiod)) { | |
9b19d40a | 205 | dev_err(&pdev->dev, "failed to request gpio"); |
d2b911db | 206 | return PTR_ERR(mtx1_wdt_device.gpiod); |
9b19d40a | 207 | } |
6ea8115b | 208 | |
ed78c2da | 209 | spin_lock_init(&mtx1_wdt_device.lock); |
04bf3b4f FF |
210 | init_completion(&mtx1_wdt_device.stop); |
211 | mtx1_wdt_device.queue = 0; | |
04bf3b4f | 212 | clear_bit(0, &mtx1_wdt_device.inuse); |
e99e88a9 | 213 | timer_setup(&mtx1_wdt_device.timer, mtx1_wdt_trigger, 0); |
04bf3b4f FF |
214 | mtx1_wdt_device.default_ticks = ticks; |
215 | ||
ed78c2da AC |
216 | ret = misc_register(&mtx1_wdt_misc); |
217 | if (ret < 0) { | |
fad0a9dd | 218 | dev_err(&pdev->dev, "failed to register\n"); |
ed78c2da AC |
219 | return ret; |
220 | } | |
04bf3b4f | 221 | mtx1_wdt_start(); |
fad0a9dd | 222 | dev_info(&pdev->dev, "MTX-1 Watchdog driver\n"); |
04bf3b4f FF |
223 | return 0; |
224 | } | |
225 | ||
4b12b896 | 226 | static int mtx1_wdt_remove(struct platform_device *pdev) |
04bf3b4f | 227 | { |
ed78c2da | 228 | /* FIXME: do we need to lock this test ? */ |
04bf3b4f FF |
229 | if (mtx1_wdt_device.queue) { |
230 | mtx1_wdt_device.queue = 0; | |
231 | wait_for_completion(&mtx1_wdt_device.stop); | |
232 | } | |
9b19d40a | 233 | |
04bf3b4f | 234 | misc_deregister(&mtx1_wdt_misc); |
6ea8115b FF |
235 | return 0; |
236 | } | |
237 | ||
db98f89a | 238 | static struct platform_driver mtx1_wdt_driver = { |
6ea8115b | 239 | .probe = mtx1_wdt_probe, |
82268714 | 240 | .remove = mtx1_wdt_remove, |
6ea8115b | 241 | .driver.name = "mtx1-wdt", |
f37d193c | 242 | .driver.owner = THIS_MODULE, |
6ea8115b FF |
243 | }; |
244 | ||
b8ec6118 | 245 | module_platform_driver(mtx1_wdt_driver); |
04bf3b4f FF |
246 | |
247 | MODULE_AUTHOR("Michael Stickel, Florian Fainelli"); | |
248 | MODULE_DESCRIPTION("Driver for the MTX-1 watchdog"); | |
249 | MODULE_LICENSE("GPL"); | |
f37d193c | 250 | MODULE_ALIAS("platform:mtx1-wdt"); |