1 | // SPDX-License-Identifier: GPL-2.0-or-later |
2 | /* |
3 | * RDC321x watchdog driver |
4 | * |
5 | * Copyright (C) 2007-2010 Florian Fainelli <florian@openwrt.org> |
6 | * |
7 | * This driver is highly inspired from the cpu5_wdt driver |
8 | */ |
9 | |
10 | #include <linux/module.h> |
11 | #include <linux/moduleparam.h> |
12 | #include <linux/types.h> |
13 | #include <linux/errno.h> |
14 | #include <linux/miscdevice.h> |
15 | #include <linux/fs.h> |
16 | #include <linux/ioport.h> |
17 | #include <linux/timer.h> |
18 | #include <linux/completion.h> |
19 | #include <linux/jiffies.h> |
20 | #include <linux/platform_device.h> |
21 | #include <linux/watchdog.h> |
22 | #include <linux/io.h> |
23 | #include <linux/uaccess.h> |
24 | #include <linux/mfd/rdc321x.h> |
25 | |
26 | #define RDC_WDT_MASK 0x80000000 /* Mask */ |
27 | #define RDC_WDT_EN 0x00800000 /* Enable bit */ |
28 | #define RDC_WDT_WTI 0x00200000 /* Generate CPU reset/NMI/WDT on timeout */ |
29 | #define RDC_WDT_RST 0x00100000 /* Reset bit */ |
30 | #define RDC_WDT_WIF 0x00040000 /* WDT IRQ Flag */ |
31 | #define RDC_WDT_IRT 0x00000100 /* IRQ Routing table */ |
32 | #define RDC_WDT_CNT 0x00000001 /* WDT count */ |
33 | |
34 | #define RDC_CLS_TMR 0x80003844 /* Clear timer */ |
35 | |
36 | #define RDC_WDT_INTERVAL (HZ/10+1) |
37 | |
38 | static int ticks = 1000; |
39 | |
40 | /* some device data */ |
41 | |
42 | static struct { |
43 | struct completion stop; |
44 | int running; |
45 | struct timer_list timer; |
46 | int queue; |
47 | int default_ticks; |
48 | unsigned long inuse; |
49 | spinlock_t lock; |
50 | struct pci_dev *sb_pdev; |
51 | int base_reg; |
52 | } rdc321x_wdt_device; |
53 | |
54 | /* generic helper functions */ |
55 | |
56 | static void rdc321x_wdt_trigger(struct timer_list *unused) |
57 | { |
58 | unsigned long flags; |
59 | u32 val; |
60 | |
61 | if (rdc321x_wdt_device.running) |
62 | ticks--; |
63 | |
64 | /* keep watchdog alive */ |
65 | spin_lock_irqsave(&rdc321x_wdt_device.lock, flags); |
66 | pci_read_config_dword(dev: rdc321x_wdt_device.sb_pdev, |
67 | where: rdc321x_wdt_device.base_reg, val: &val); |
68 | val |= RDC_WDT_EN; |
69 | pci_write_config_dword(dev: rdc321x_wdt_device.sb_pdev, |
70 | where: rdc321x_wdt_device.base_reg, val); |
71 | spin_unlock_irqrestore(lock: &rdc321x_wdt_device.lock, flags); |
72 | |
73 | /* requeue?? */ |
74 | if (rdc321x_wdt_device.queue && ticks) |
75 | mod_timer(timer: &rdc321x_wdt_device.timer, |
76 | expires: jiffies + RDC_WDT_INTERVAL); |
77 | else { |
78 | /* ticks doesn't matter anyway */ |
79 | complete(&rdc321x_wdt_device.stop); |
80 | } |
81 | |
82 | } |
83 | |
84 | static void rdc321x_wdt_reset(void) |
85 | { |
86 | ticks = rdc321x_wdt_device.default_ticks; |
87 | } |
88 | |
89 | static void rdc321x_wdt_start(void) |
90 | { |
91 | unsigned long flags; |
92 | |
93 | if (!rdc321x_wdt_device.queue) { |
94 | rdc321x_wdt_device.queue = 1; |
95 | |
96 | /* Clear the timer */ |
97 | spin_lock_irqsave(&rdc321x_wdt_device.lock, flags); |
98 | pci_write_config_dword(dev: rdc321x_wdt_device.sb_pdev, |
99 | where: rdc321x_wdt_device.base_reg, RDC_CLS_TMR); |
100 | |
101 | /* Enable watchdog and set the timeout to 81.92 us */ |
102 | pci_write_config_dword(dev: rdc321x_wdt_device.sb_pdev, |
103 | where: rdc321x_wdt_device.base_reg, |
104 | RDC_WDT_EN | RDC_WDT_CNT); |
105 | spin_unlock_irqrestore(lock: &rdc321x_wdt_device.lock, flags); |
106 | |
107 | mod_timer(timer: &rdc321x_wdt_device.timer, |
108 | expires: jiffies + RDC_WDT_INTERVAL); |
109 | } |
110 | |
111 | /* if process dies, counter is not decremented */ |
112 | rdc321x_wdt_device.running++; |
113 | } |
114 | |
115 | static int rdc321x_wdt_stop(void) |
116 | { |
117 | if (rdc321x_wdt_device.running) |
118 | rdc321x_wdt_device.running = 0; |
119 | |
120 | ticks = rdc321x_wdt_device.default_ticks; |
121 | |
122 | return -EIO; |
123 | } |
124 | |
125 | /* filesystem operations */ |
126 | static int rdc321x_wdt_open(struct inode *inode, struct file *file) |
127 | { |
128 | if (test_and_set_bit(nr: 0, addr: &rdc321x_wdt_device.inuse)) |
129 | return -EBUSY; |
130 | |
131 | return stream_open(inode, filp: file); |
132 | } |
133 | |
134 | static int rdc321x_wdt_release(struct inode *inode, struct file *file) |
135 | { |
136 | clear_bit(nr: 0, addr: &rdc321x_wdt_device.inuse); |
137 | return 0; |
138 | } |
139 | |
140 | static long rdc321x_wdt_ioctl(struct file *file, unsigned int cmd, |
141 | unsigned long arg) |
142 | { |
143 | void __user *argp = (void __user *)arg; |
144 | u32 value; |
145 | static const struct watchdog_info ident = { |
146 | .options = WDIOF_CARDRESET, |
147 | .identity = "RDC321x WDT" , |
148 | }; |
149 | unsigned long flags; |
150 | |
151 | switch (cmd) { |
152 | case WDIOC_KEEPALIVE: |
153 | rdc321x_wdt_reset(); |
154 | break; |
155 | case WDIOC_GETSTATUS: |
156 | /* Read the value from the DATA register */ |
157 | spin_lock_irqsave(&rdc321x_wdt_device.lock, flags); |
158 | pci_read_config_dword(dev: rdc321x_wdt_device.sb_pdev, |
159 | where: rdc321x_wdt_device.base_reg, val: &value); |
160 | spin_unlock_irqrestore(lock: &rdc321x_wdt_device.lock, flags); |
161 | if (copy_to_user(to: argp, from: &value, n: sizeof(u32))) |
162 | return -EFAULT; |
163 | break; |
164 | case WDIOC_GETSUPPORT: |
165 | if (copy_to_user(to: argp, from: &ident, n: sizeof(ident))) |
166 | return -EFAULT; |
167 | break; |
168 | case WDIOC_SETOPTIONS: |
169 | if (copy_from_user(to: &value, from: argp, n: sizeof(int))) |
170 | return -EFAULT; |
171 | switch (value) { |
172 | case WDIOS_ENABLECARD: |
173 | rdc321x_wdt_start(); |
174 | break; |
175 | case WDIOS_DISABLECARD: |
176 | return rdc321x_wdt_stop(); |
177 | default: |
178 | return -EINVAL; |
179 | } |
180 | break; |
181 | default: |
182 | return -ENOTTY; |
183 | } |
184 | return 0; |
185 | } |
186 | |
187 | static ssize_t rdc321x_wdt_write(struct file *file, const char __user *buf, |
188 | size_t count, loff_t *ppos) |
189 | { |
190 | if (!count) |
191 | return -EIO; |
192 | |
193 | rdc321x_wdt_reset(); |
194 | |
195 | return count; |
196 | } |
197 | |
198 | static const struct file_operations rdc321x_wdt_fops = { |
199 | .owner = THIS_MODULE, |
200 | .llseek = no_llseek, |
201 | .unlocked_ioctl = rdc321x_wdt_ioctl, |
202 | .compat_ioctl = compat_ptr_ioctl, |
203 | .open = rdc321x_wdt_open, |
204 | .write = rdc321x_wdt_write, |
205 | .release = rdc321x_wdt_release, |
206 | }; |
207 | |
208 | static struct miscdevice rdc321x_wdt_misc = { |
209 | .minor = WATCHDOG_MINOR, |
210 | .name = "watchdog" , |
211 | .fops = &rdc321x_wdt_fops, |
212 | }; |
213 | |
214 | static int rdc321x_wdt_probe(struct platform_device *pdev) |
215 | { |
216 | int err; |
217 | struct resource *r; |
218 | struct rdc321x_wdt_pdata *pdata; |
219 | |
220 | pdata = dev_get_platdata(dev: &pdev->dev); |
221 | if (!pdata) { |
222 | dev_err(&pdev->dev, "no platform data supplied\n" ); |
223 | return -ENODEV; |
224 | } |
225 | |
226 | r = platform_get_resource_byname(pdev, IORESOURCE_IO, "wdt-reg" ); |
227 | if (!r) { |
228 | dev_err(&pdev->dev, "failed to get wdt-reg resource\n" ); |
229 | return -ENODEV; |
230 | } |
231 | |
232 | rdc321x_wdt_device.sb_pdev = pdata->sb_pdev; |
233 | rdc321x_wdt_device.base_reg = r->start; |
234 | rdc321x_wdt_device.queue = 0; |
235 | rdc321x_wdt_device.default_ticks = ticks; |
236 | |
237 | err = misc_register(misc: &rdc321x_wdt_misc); |
238 | if (err < 0) { |
239 | dev_err(&pdev->dev, "misc_register failed\n" ); |
240 | return err; |
241 | } |
242 | |
243 | spin_lock_init(&rdc321x_wdt_device.lock); |
244 | |
245 | /* Reset the watchdog */ |
246 | pci_write_config_dword(dev: rdc321x_wdt_device.sb_pdev, |
247 | where: rdc321x_wdt_device.base_reg, RDC_WDT_RST); |
248 | |
249 | init_completion(x: &rdc321x_wdt_device.stop); |
250 | |
251 | clear_bit(nr: 0, addr: &rdc321x_wdt_device.inuse); |
252 | |
253 | timer_setup(&rdc321x_wdt_device.timer, rdc321x_wdt_trigger, 0); |
254 | |
255 | dev_info(&pdev->dev, "watchdog init success\n" ); |
256 | |
257 | return 0; |
258 | } |
259 | |
260 | static void rdc321x_wdt_remove(struct platform_device *pdev) |
261 | { |
262 | if (rdc321x_wdt_device.queue) { |
263 | rdc321x_wdt_device.queue = 0; |
264 | wait_for_completion(&rdc321x_wdt_device.stop); |
265 | } |
266 | |
267 | misc_deregister(misc: &rdc321x_wdt_misc); |
268 | } |
269 | |
270 | static struct platform_driver rdc321x_wdt_driver = { |
271 | .probe = rdc321x_wdt_probe, |
272 | .remove_new = rdc321x_wdt_remove, |
273 | .driver = { |
274 | .name = "rdc321x-wdt" , |
275 | }, |
276 | }; |
277 | |
278 | module_platform_driver(rdc321x_wdt_driver); |
279 | |
280 | MODULE_AUTHOR("Florian Fainelli <florian@openwrt.org>" ); |
281 | MODULE_DESCRIPTION("RDC321x watchdog driver" ); |
282 | MODULE_LICENSE("GPL" ); |
283 | |