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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 | ||
3be10211 JC |
18 | #include <linux/fs.h> |
19 | #include <linux/init.h> | |
20 | #include <linux/kernel.h> | |
21 | #include <linux/miscdevice.h> | |
22 | #include <linux/module.h> | |
23 | #include <linux/watchdog.h> | |
d052d1be RK |
24 | #include <linux/platform_device.h> |
25 | ||
3be10211 JC |
26 | #include <asm/mv64x60.h> |
27 | #include <asm/uaccess.h> | |
28 | #include <asm/io.h> | |
29 | ||
30 | /* MV64x60 WDC (config) register access definitions */ | |
31 | #define MV64x60_WDC_CTL1_MASK (3 << 24) | |
32 | #define MV64x60_WDC_CTL1(val) ((val & 3) << 24) | |
33 | #define MV64x60_WDC_CTL2_MASK (3 << 26) | |
34 | #define MV64x60_WDC_CTL2(val) ((val & 3) << 26) | |
35 | ||
36 | /* Flags bits */ | |
37 | #define MV64x60_WDOG_FLAG_OPENED 0 | |
38 | #define MV64x60_WDOG_FLAG_ENABLED 1 | |
39 | ||
40 | static unsigned long wdt_flags; | |
41 | static int wdt_status; | |
42 | static void __iomem *mv64x60_regs; | |
43 | static int mv64x60_wdt_timeout; | |
44 | ||
45 | static void mv64x60_wdt_reg_write(u32 val) | |
46 | { | |
47 | /* Allow write only to CTL1 / CTL2 fields, retaining values in | |
48 | * other fields. | |
49 | */ | |
50 | u32 data = readl(mv64x60_regs + MV64x60_WDT_WDC); | |
51 | data &= ~(MV64x60_WDC_CTL1_MASK | MV64x60_WDC_CTL2_MASK); | |
52 | data |= val; | |
53 | writel(data, mv64x60_regs + MV64x60_WDT_WDC); | |
54 | } | |
55 | ||
56 | static void mv64x60_wdt_service(void) | |
57 | { | |
58 | /* Write 01 followed by 10 to CTL2 */ | |
59 | mv64x60_wdt_reg_write(MV64x60_WDC_CTL2(0x01)); | |
60 | mv64x60_wdt_reg_write(MV64x60_WDC_CTL2(0x02)); | |
61 | } | |
62 | ||
63 | static void mv64x60_wdt_handler_disable(void) | |
64 | { | |
65 | if (test_and_clear_bit(MV64x60_WDOG_FLAG_ENABLED, &wdt_flags)) { | |
66 | /* Write 01 followed by 10 to CTL1 */ | |
67 | mv64x60_wdt_reg_write(MV64x60_WDC_CTL1(0x01)); | |
68 | mv64x60_wdt_reg_write(MV64x60_WDC_CTL1(0x02)); | |
69 | printk(KERN_NOTICE "mv64x60_wdt: watchdog deactivated\n"); | |
70 | } | |
71 | } | |
72 | ||
73 | static void mv64x60_wdt_handler_enable(void) | |
74 | { | |
75 | if (!test_and_set_bit(MV64x60_WDOG_FLAG_ENABLED, &wdt_flags)) { | |
76 | /* Write 01 followed by 10 to CTL1 */ | |
77 | mv64x60_wdt_reg_write(MV64x60_WDC_CTL1(0x01)); | |
78 | mv64x60_wdt_reg_write(MV64x60_WDC_CTL1(0x02)); | |
79 | printk(KERN_NOTICE "mv64x60_wdt: watchdog activated\n"); | |
80 | } | |
81 | } | |
82 | ||
83 | static int mv64x60_wdt_open(struct inode *inode, struct file *file) | |
84 | { | |
85 | if (test_and_set_bit(MV64x60_WDOG_FLAG_OPENED, &wdt_flags)) | |
86 | return -EBUSY; | |
87 | ||
88 | mv64x60_wdt_service(); | |
89 | mv64x60_wdt_handler_enable(); | |
90 | ||
b2846dfa AV |
91 | nonseekable_open(inode, file); |
92 | ||
3be10211 JC |
93 | return 0; |
94 | } | |
95 | ||
96 | static int mv64x60_wdt_release(struct inode *inode, struct file *file) | |
97 | { | |
98 | mv64x60_wdt_service(); | |
99 | ||
100 | #if !defined(CONFIG_WATCHDOG_NOWAYOUT) | |
101 | mv64x60_wdt_handler_disable(); | |
102 | #endif | |
103 | ||
104 | clear_bit(MV64x60_WDOG_FLAG_OPENED, &wdt_flags); | |
105 | ||
106 | return 0; | |
107 | } | |
108 | ||
b2846dfa | 109 | static ssize_t mv64x60_wdt_write(struct file *file, const char __user *data, |
3be10211 JC |
110 | size_t len, loff_t * ppos) |
111 | { | |
3be10211 JC |
112 | if (len) |
113 | mv64x60_wdt_service(); | |
114 | ||
115 | return len; | |
116 | } | |
117 | ||
118 | static int mv64x60_wdt_ioctl(struct inode *inode, struct file *file, | |
119 | unsigned int cmd, unsigned long arg) | |
120 | { | |
121 | int timeout; | |
b2846dfa | 122 | void __user *argp = (void __user *)arg; |
3be10211 JC |
123 | static struct watchdog_info info = { |
124 | .options = WDIOF_KEEPALIVEPING, | |
125 | .firmware_version = 0, | |
126 | .identity = "MV64x60 watchdog", | |
127 | }; | |
128 | ||
129 | switch (cmd) { | |
130 | case WDIOC_GETSUPPORT: | |
b2846dfa | 131 | if (copy_to_user(argp, &info, sizeof(info))) |
3be10211 JC |
132 | return -EFAULT; |
133 | break; | |
134 | ||
135 | case WDIOC_GETSTATUS: | |
136 | case WDIOC_GETBOOTSTATUS: | |
b2846dfa | 137 | if (put_user(wdt_status, (int __user *)argp)) |
3be10211 JC |
138 | return -EFAULT; |
139 | wdt_status &= ~WDIOF_KEEPALIVEPING; | |
140 | break; | |
141 | ||
142 | case WDIOC_GETTEMP: | |
143 | return -EOPNOTSUPP; | |
144 | ||
145 | case WDIOC_SETOPTIONS: | |
146 | return -EOPNOTSUPP; | |
147 | ||
148 | case WDIOC_KEEPALIVE: | |
149 | mv64x60_wdt_service(); | |
150 | wdt_status |= WDIOF_KEEPALIVEPING; | |
151 | break; | |
152 | ||
153 | case WDIOC_SETTIMEOUT: | |
154 | return -EOPNOTSUPP; | |
155 | ||
156 | case WDIOC_GETTIMEOUT: | |
157 | timeout = mv64x60_wdt_timeout * HZ; | |
b2846dfa | 158 | if (put_user(timeout, (int __user *)argp)) |
3be10211 JC |
159 | return -EFAULT; |
160 | break; | |
161 | ||
162 | default: | |
163 | return -ENOIOCTLCMD; | |
164 | } | |
165 | ||
166 | return 0; | |
167 | } | |
168 | ||
62322d25 | 169 | static const struct file_operations mv64x60_wdt_fops = { |
3be10211 JC |
170 | .owner = THIS_MODULE, |
171 | .llseek = no_llseek, | |
172 | .write = mv64x60_wdt_write, | |
173 | .ioctl = mv64x60_wdt_ioctl, | |
174 | .open = mv64x60_wdt_open, | |
175 | .release = mv64x60_wdt_release, | |
176 | }; | |
177 | ||
178 | static struct miscdevice mv64x60_wdt_miscdev = { | |
179 | .minor = WATCHDOG_MINOR, | |
180 | .name = "watchdog", | |
181 | .fops = &mv64x60_wdt_fops, | |
182 | }; | |
183 | ||
3ae5eaec | 184 | static int __devinit mv64x60_wdt_probe(struct platform_device *dev) |
3be10211 | 185 | { |
3ae5eaec | 186 | struct mv64x60_wdt_pdata *pdata = dev->dev.platform_data; |
3be10211 JC |
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 | ||
3ae5eaec | 203 | static int __devexit mv64x60_wdt_remove(struct platform_device *dev) |
3be10211 JC |
204 | { |
205 | misc_deregister(&mv64x60_wdt_miscdev); | |
206 | ||
207 | mv64x60_wdt_service(); | |
208 | mv64x60_wdt_handler_disable(); | |
209 | ||
210 | return 0; | |
211 | } | |
212 | ||
3ae5eaec | 213 | static struct platform_driver mv64x60_wdt_driver = { |
3be10211 JC |
214 | .probe = mv64x60_wdt_probe, |
215 | .remove = __devexit_p(mv64x60_wdt_remove), | |
3ae5eaec RK |
216 | .driver = { |
217 | .owner = THIS_MODULE, | |
218 | .name = MV64x60_WDT_NAME, | |
219 | }, | |
3be10211 JC |
220 | }; |
221 | ||
222 | static struct platform_device *mv64x60_wdt_dev; | |
223 | ||
224 | static int __init mv64x60_wdt_init(void) | |
225 | { | |
226 | int ret; | |
227 | ||
228 | printk(KERN_INFO "MV64x60 watchdog driver\n"); | |
229 | ||
eee8ab75 DT |
230 | mv64x60_wdt_dev = platform_device_alloc(MV64x60_WDT_NAME, -1); |
231 | if (!mv64x60_wdt_dev) { | |
232 | ret = -ENOMEM; | |
233 | goto out; | |
234 | } | |
235 | ||
236 | ret = platform_device_add(mv64x60_wdt_dev); | |
237 | if (ret) { | |
238 | platform_device_put(mv64x60_wdt_dev); | |
3be10211 JC |
239 | goto out; |
240 | } | |
241 | ||
3ae5eaec | 242 | ret = platform_driver_register(&mv64x60_wdt_driver); |
eee8ab75 DT |
243 | if (ret) { |
244 | platform_device_unregister(mv64x60_wdt_dev); | |
245 | goto out; | |
246 | } | |
247 | ||
248 | out: | |
3be10211 JC |
249 | return ret; |
250 | } | |
251 | ||
252 | static void __exit mv64x60_wdt_exit(void) | |
253 | { | |
3ae5eaec | 254 | platform_driver_unregister(&mv64x60_wdt_driver); |
3be10211 JC |
255 | platform_device_unregister(mv64x60_wdt_dev); |
256 | } | |
257 | ||
258 | module_init(mv64x60_wdt_init); | |
259 | module_exit(mv64x60_wdt_exit); | |
260 | ||
261 | MODULE_AUTHOR("James Chapman <jchapman@katalix.com>"); | |
262 | MODULE_DESCRIPTION("MV64x60 watchdog driver"); | |
263 | MODULE_LICENSE("GPL"); | |
264 | MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); |