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3be10211 JC |
1 | /* |
2 | * mv64x60_wdt.c - MV64X60 (Marvell Discovery) watchdog userspace interface | |
3 | * | |
4 | * Author: James Chapman <jchapman@katalix.com> | |
5 | * | |
6 | * Platform-specific setup code should configure the dog to generate | |
7 | * interrupt or reset as required. This code only enables/disables | |
8 | * and services the watchdog. | |
9 | * | |
10 | * Derived from mpc8xx_wdt.c, with the following copyright. | |
11 | * | |
12 | * 2002 (c) Florian Schirmer <jolt@tuxbox.org> This file is licensed under | |
13 | * the terms of the GNU General Public License version 2. This program | |
14 | * is licensed "as is" without any warranty of any kind, whether express | |
15 | * or implied. | |
16 | */ | |
17 | ||
18 | #include <linux/config.h> | |
19 | #include <linux/fs.h> | |
20 | #include <linux/init.h> | |
21 | #include <linux/kernel.h> | |
22 | #include <linux/miscdevice.h> | |
23 | #include <linux/module.h> | |
24 | #include <linux/watchdog.h> | |
25 | #include <asm/mv64x60.h> | |
26 | #include <asm/uaccess.h> | |
27 | #include <asm/io.h> | |
28 | ||
29 | /* MV64x60 WDC (config) register access definitions */ | |
30 | #define MV64x60_WDC_CTL1_MASK (3 << 24) | |
31 | #define MV64x60_WDC_CTL1(val) ((val & 3) << 24) | |
32 | #define MV64x60_WDC_CTL2_MASK (3 << 26) | |
33 | #define MV64x60_WDC_CTL2(val) ((val & 3) << 26) | |
34 | ||
35 | /* Flags bits */ | |
36 | #define MV64x60_WDOG_FLAG_OPENED 0 | |
37 | #define MV64x60_WDOG_FLAG_ENABLED 1 | |
38 | ||
39 | static unsigned long wdt_flags; | |
40 | static int wdt_status; | |
41 | static void __iomem *mv64x60_regs; | |
42 | static int mv64x60_wdt_timeout; | |
43 | ||
44 | static void mv64x60_wdt_reg_write(u32 val) | |
45 | { | |
46 | /* Allow write only to CTL1 / CTL2 fields, retaining values in | |
47 | * other fields. | |
48 | */ | |
49 | u32 data = readl(mv64x60_regs + MV64x60_WDT_WDC); | |
50 | data &= ~(MV64x60_WDC_CTL1_MASK | MV64x60_WDC_CTL2_MASK); | |
51 | data |= val; | |
52 | writel(data, mv64x60_regs + MV64x60_WDT_WDC); | |
53 | } | |
54 | ||
55 | static void mv64x60_wdt_service(void) | |
56 | { | |
57 | /* Write 01 followed by 10 to CTL2 */ | |
58 | mv64x60_wdt_reg_write(MV64x60_WDC_CTL2(0x01)); | |
59 | mv64x60_wdt_reg_write(MV64x60_WDC_CTL2(0x02)); | |
60 | } | |
61 | ||
62 | static void mv64x60_wdt_handler_disable(void) | |
63 | { | |
64 | if (test_and_clear_bit(MV64x60_WDOG_FLAG_ENABLED, &wdt_flags)) { | |
65 | /* Write 01 followed by 10 to CTL1 */ | |
66 | mv64x60_wdt_reg_write(MV64x60_WDC_CTL1(0x01)); | |
67 | mv64x60_wdt_reg_write(MV64x60_WDC_CTL1(0x02)); | |
68 | printk(KERN_NOTICE "mv64x60_wdt: watchdog deactivated\n"); | |
69 | } | |
70 | } | |
71 | ||
72 | static void mv64x60_wdt_handler_enable(void) | |
73 | { | |
74 | if (!test_and_set_bit(MV64x60_WDOG_FLAG_ENABLED, &wdt_flags)) { | |
75 | /* Write 01 followed by 10 to CTL1 */ | |
76 | mv64x60_wdt_reg_write(MV64x60_WDC_CTL1(0x01)); | |
77 | mv64x60_wdt_reg_write(MV64x60_WDC_CTL1(0x02)); | |
78 | printk(KERN_NOTICE "mv64x60_wdt: watchdog activated\n"); | |
79 | } | |
80 | } | |
81 | ||
82 | static int mv64x60_wdt_open(struct inode *inode, struct file *file) | |
83 | { | |
84 | if (test_and_set_bit(MV64x60_WDOG_FLAG_OPENED, &wdt_flags)) | |
85 | return -EBUSY; | |
86 | ||
87 | mv64x60_wdt_service(); | |
88 | mv64x60_wdt_handler_enable(); | |
89 | ||
b2846dfa AV |
90 | nonseekable_open(inode, file); |
91 | ||
3be10211 JC |
92 | return 0; |
93 | } | |
94 | ||
95 | static int mv64x60_wdt_release(struct inode *inode, struct file *file) | |
96 | { | |
97 | mv64x60_wdt_service(); | |
98 | ||
99 | #if !defined(CONFIG_WATCHDOG_NOWAYOUT) | |
100 | mv64x60_wdt_handler_disable(); | |
101 | #endif | |
102 | ||
103 | clear_bit(MV64x60_WDOG_FLAG_OPENED, &wdt_flags); | |
104 | ||
105 | return 0; | |
106 | } | |
107 | ||
b2846dfa | 108 | static ssize_t mv64x60_wdt_write(struct file *file, const char __user *data, |
3be10211 JC |
109 | size_t len, loff_t * ppos) |
110 | { | |
3be10211 JC |
111 | if (len) |
112 | mv64x60_wdt_service(); | |
113 | ||
114 | return len; | |
115 | } | |
116 | ||
117 | static int mv64x60_wdt_ioctl(struct inode *inode, struct file *file, | |
118 | unsigned int cmd, unsigned long arg) | |
119 | { | |
120 | int timeout; | |
b2846dfa | 121 | void __user *argp = (void __user *)arg; |
3be10211 JC |
122 | static struct watchdog_info info = { |
123 | .options = WDIOF_KEEPALIVEPING, | |
124 | .firmware_version = 0, | |
125 | .identity = "MV64x60 watchdog", | |
126 | }; | |
127 | ||
128 | switch (cmd) { | |
129 | case WDIOC_GETSUPPORT: | |
b2846dfa | 130 | if (copy_to_user(argp, &info, sizeof(info))) |
3be10211 JC |
131 | return -EFAULT; |
132 | break; | |
133 | ||
134 | case WDIOC_GETSTATUS: | |
135 | case WDIOC_GETBOOTSTATUS: | |
b2846dfa | 136 | if (put_user(wdt_status, (int __user *)argp)) |
3be10211 JC |
137 | return -EFAULT; |
138 | wdt_status &= ~WDIOF_KEEPALIVEPING; | |
139 | break; | |
140 | ||
141 | case WDIOC_GETTEMP: | |
142 | return -EOPNOTSUPP; | |
143 | ||
144 | case WDIOC_SETOPTIONS: | |
145 | return -EOPNOTSUPP; | |
146 | ||
147 | case WDIOC_KEEPALIVE: | |
148 | mv64x60_wdt_service(); | |
149 | wdt_status |= WDIOF_KEEPALIVEPING; | |
150 | break; | |
151 | ||
152 | case WDIOC_SETTIMEOUT: | |
153 | return -EOPNOTSUPP; | |
154 | ||
155 | case WDIOC_GETTIMEOUT: | |
156 | timeout = mv64x60_wdt_timeout * HZ; | |
b2846dfa | 157 | if (put_user(timeout, (int __user *)argp)) |
3be10211 JC |
158 | return -EFAULT; |
159 | break; | |
160 | ||
161 | default: | |
162 | return -ENOIOCTLCMD; | |
163 | } | |
164 | ||
165 | return 0; | |
166 | } | |
167 | ||
168 | static struct file_operations mv64x60_wdt_fops = { | |
169 | .owner = THIS_MODULE, | |
170 | .llseek = no_llseek, | |
171 | .write = mv64x60_wdt_write, | |
172 | .ioctl = mv64x60_wdt_ioctl, | |
173 | .open = mv64x60_wdt_open, | |
174 | .release = mv64x60_wdt_release, | |
175 | }; | |
176 | ||
177 | static struct miscdevice mv64x60_wdt_miscdev = { | |
178 | .minor = WATCHDOG_MINOR, | |
179 | .name = "watchdog", | |
180 | .fops = &mv64x60_wdt_fops, | |
181 | }; | |
182 | ||
183 | static int __devinit mv64x60_wdt_probe(struct device *dev) | |
184 | { | |
185 | struct platform_device *pd = to_platform_device(dev); | |
186 | struct mv64x60_wdt_pdata *pdata = pd->dev.platform_data; | |
187 | int bus_clk = 133; | |
188 | ||
189 | mv64x60_wdt_timeout = 10; | |
190 | if (pdata) { | |
191 | mv64x60_wdt_timeout = pdata->timeout; | |
192 | bus_clk = pdata->bus_clk; | |
193 | } | |
194 | ||
195 | mv64x60_regs = mv64x60_get_bridge_vbase(); | |
196 | ||
197 | writel((mv64x60_wdt_timeout * (bus_clk * 1000000)) >> 8, | |
198 | mv64x60_regs + MV64x60_WDT_WDC); | |
199 | ||
200 | return misc_register(&mv64x60_wdt_miscdev); | |
201 | } | |
202 | ||
203 | static int __devexit mv64x60_wdt_remove(struct device *dev) | |
204 | { | |
205 | misc_deregister(&mv64x60_wdt_miscdev); | |
206 | ||
207 | mv64x60_wdt_service(); | |
208 | mv64x60_wdt_handler_disable(); | |
209 | ||
210 | return 0; | |
211 | } | |
212 | ||
213 | static struct device_driver mv64x60_wdt_driver = { | |
214 | .name = MV64x60_WDT_NAME, | |
215 | .bus = &platform_bus_type, | |
216 | .probe = mv64x60_wdt_probe, | |
217 | .remove = __devexit_p(mv64x60_wdt_remove), | |
218 | }; | |
219 | ||
220 | static struct platform_device *mv64x60_wdt_dev; | |
221 | ||
222 | static int __init mv64x60_wdt_init(void) | |
223 | { | |
224 | int ret; | |
225 | ||
226 | printk(KERN_INFO "MV64x60 watchdog driver\n"); | |
227 | ||
228 | mv64x60_wdt_dev = platform_device_register_simple(MV64x60_WDT_NAME, | |
229 | -1, NULL, 0); | |
230 | if (IS_ERR(mv64x60_wdt_dev)) { | |
231 | ret = PTR_ERR(mv64x60_wdt_dev); | |
232 | goto out; | |
233 | } | |
234 | ||
235 | ret = driver_register(&mv64x60_wdt_driver); | |
236 | out: | |
237 | return ret; | |
238 | } | |
239 | ||
240 | static void __exit mv64x60_wdt_exit(void) | |
241 | { | |
242 | driver_unregister(&mv64x60_wdt_driver); | |
243 | platform_device_unregister(mv64x60_wdt_dev); | |
244 | } | |
245 | ||
246 | module_init(mv64x60_wdt_init); | |
247 | module_exit(mv64x60_wdt_exit); | |
248 | ||
249 | MODULE_AUTHOR("James Chapman <jchapman@katalix.com>"); | |
250 | MODULE_DESCRIPTION("MV64x60 watchdog driver"); | |
251 | MODULE_LICENSE("GPL"); | |
252 | MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); |