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9
10#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
11
12#include <linux/module.h>
13#include <linux/fs.h>
14#include <linux/miscdevice.h>
15#include <linux/watchdog.h>
16#include <linux/of_platform.h>
17#include <linux/uaccess.h>
18#include <linux/clk.h>
19#include <linux/io.h>
20
21#include <lantiq_soc.h>
22
23
24
25
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29
30
31#define LTQ_WDT_PW1 0x00BE0000
32#define LTQ_WDT_PW2 0x00DC0000
33
34#define LTQ_WDT_CR 0x0
35#define LTQ_WDT_SR 0x8
36
37#define LTQ_WDT_SR_EN (0x1 << 31)
38#define LTQ_WDT_SR_PWD (0x3 << 26)
39#define LTQ_WDT_SR_CLKDIV (0x3 << 24)
40
41#define LTQ_WDT_DIVIDER 0x40000
42#define LTQ_MAX_TIMEOUT ((1 << 16) - 1)
43
44static bool nowayout = WATCHDOG_NOWAYOUT;
45
46static void __iomem *ltq_wdt_membase;
47static unsigned long ltq_io_region_clk_rate;
48
49static unsigned long ltq_wdt_bootstatus;
50static unsigned long ltq_wdt_in_use;
51static int ltq_wdt_timeout = 30;
52static int ltq_wdt_ok_to_close;
53
54static void
55ltq_wdt_enable(void)
56{
57 unsigned long int timeout = ltq_wdt_timeout *
58 (ltq_io_region_clk_rate / LTQ_WDT_DIVIDER) + 0x1000;
59 if (timeout > LTQ_MAX_TIMEOUT)
60 timeout = LTQ_MAX_TIMEOUT;
61
62
63 ltq_w32(LTQ_WDT_PW1, ltq_wdt_membase + LTQ_WDT_CR);
64
65 ltq_w32(LTQ_WDT_SR_EN | LTQ_WDT_SR_PWD | LTQ_WDT_SR_CLKDIV |
66 LTQ_WDT_PW2 | timeout, ltq_wdt_membase + LTQ_WDT_CR);
67}
68
69static void
70ltq_wdt_disable(void)
71{
72
73 ltq_w32(LTQ_WDT_PW1, ltq_wdt_membase + LTQ_WDT_CR);
74
75
76
77
78 ltq_w32(LTQ_WDT_PW2, ltq_wdt_membase + LTQ_WDT_CR);
79}
80
81static ssize_t
82ltq_wdt_write(struct file *file, const char __user *data,
83 size_t len, loff_t *ppos)
84{
85 if (len) {
86 if (!nowayout) {
87 size_t i;
88
89 ltq_wdt_ok_to_close = 0;
90 for (i = 0; i != len; i++) {
91 char c;
92
93 if (get_user(c, data + i))
94 return -EFAULT;
95 if (c == 'V')
96 ltq_wdt_ok_to_close = 1;
97 else
98 ltq_wdt_ok_to_close = 0;
99 }
100 }
101 ltq_wdt_enable();
102 }
103
104 return len;
105}
106
107static struct watchdog_info ident = {
108 .options = WDIOF_MAGICCLOSE | WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING |
109 WDIOF_CARDRESET,
110 .identity = "ltq_wdt",
111};
112
113static long
114ltq_wdt_ioctl(struct file *file,
115 unsigned int cmd, unsigned long arg)
116{
117 int ret = -ENOTTY;
118
119 switch (cmd) {
120 case WDIOC_GETSUPPORT:
121 ret = copy_to_user((struct watchdog_info __user *)arg, &ident,
122 sizeof(ident)) ? -EFAULT : 0;
123 break;
124
125 case WDIOC_GETBOOTSTATUS:
126 ret = put_user(ltq_wdt_bootstatus, (int __user *)arg);
127 break;
128
129 case WDIOC_GETSTATUS:
130 ret = put_user(0, (int __user *)arg);
131 break;
132
133 case WDIOC_SETTIMEOUT:
134 ret = get_user(ltq_wdt_timeout, (int __user *)arg);
135 if (!ret)
136 ltq_wdt_enable();
137
138 case WDIOC_GETTIMEOUT:
139 ret = put_user(ltq_wdt_timeout, (int __user *)arg);
140 break;
141
142 case WDIOC_KEEPALIVE:
143 ltq_wdt_enable();
144 ret = 0;
145 break;
146 }
147 return ret;
148}
149
150static int
151ltq_wdt_open(struct inode *inode, struct file *file)
152{
153 if (test_and_set_bit(0, <q_wdt_in_use))
154 return -EBUSY;
155 ltq_wdt_in_use = 1;
156 ltq_wdt_enable();
157
158 return nonseekable_open(inode, file);
159}
160
161static int
162ltq_wdt_release(struct inode *inode, struct file *file)
163{
164 if (ltq_wdt_ok_to_close)
165 ltq_wdt_disable();
166 else
167 pr_err("watchdog closed without warning\n");
168 ltq_wdt_ok_to_close = 0;
169 clear_bit(0, <q_wdt_in_use);
170
171 return 0;
172}
173
174static const struct file_operations ltq_wdt_fops = {
175 .owner = THIS_MODULE,
176 .write = ltq_wdt_write,
177 .unlocked_ioctl = ltq_wdt_ioctl,
178 .open = ltq_wdt_open,
179 .release = ltq_wdt_release,
180 .llseek = no_llseek,
181};
182
183static struct miscdevice ltq_wdt_miscdev = {
184 .minor = WATCHDOG_MINOR,
185 .name = "watchdog",
186 .fops = <q_wdt_fops,
187};
188
189static int
190ltq_wdt_probe(struct platform_device *pdev)
191{
192 struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
193 struct clk *clk;
194
195 if (!res) {
196 dev_err(&pdev->dev, "cannot obtain I/O memory region");
197 return -ENOENT;
198 }
199
200 ltq_wdt_membase = devm_ioremap_resource(&pdev->dev, res);
201 if (IS_ERR(ltq_wdt_membase))
202 return PTR_ERR(ltq_wdt_membase);
203
204
205 clk = clk_get_io();
206 if (IS_ERR(clk)) {
207 dev_err(&pdev->dev, "Failed to get clock\n");
208 return -ENOENT;
209 }
210 ltq_io_region_clk_rate = clk_get_rate(clk);
211 clk_put(clk);
212
213
214 if (ltq_reset_cause() == LTQ_RST_CAUSE_WDTRST)
215 ltq_wdt_bootstatus = WDIOF_CARDRESET;
216
217 dev_info(&pdev->dev, "Init done\n");
218 return misc_register(<q_wdt_miscdev);
219}
220
221static int
222ltq_wdt_remove(struct platform_device *pdev)
223{
224 misc_deregister(<q_wdt_miscdev);
225
226 return 0;
227}
228
229static const struct of_device_id ltq_wdt_match[] = {
230 { .compatible = "lantiq,wdt" },
231 {},
232};
233MODULE_DEVICE_TABLE(of, ltq_wdt_match);
234
235static struct platform_driver ltq_wdt_driver = {
236 .probe = ltq_wdt_probe,
237 .remove = ltq_wdt_remove,
238 .driver = {
239 .name = "wdt",
240 .owner = THIS_MODULE,
241 .of_match_table = ltq_wdt_match,
242 },
243};
244
245module_platform_driver(ltq_wdt_driver);
246
247module_param(nowayout, bool, 0);
248MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started");
249MODULE_AUTHOR("John Crispin <blogic@openwrt.org>");
250MODULE_DESCRIPTION("Lantiq SoC Watchdog");
251MODULE_LICENSE("GPL");
252MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
253