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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 | ||
7e07a159 | 26 | #include <linux/mv643xx.h> |
3be10211 JC |
27 | #include <asm/uaccess.h> |
28 | #include <asm/io.h> | |
29 | ||
8a5cfa64 DF |
30 | #define MV64x60_WDT_WDC_OFFSET 0 |
31 | ||
3be10211 JC |
32 | /* MV64x60 WDC (config) register access definitions */ |
33 | #define MV64x60_WDC_CTL1_MASK (3 << 24) | |
34 | #define MV64x60_WDC_CTL1(val) ((val & 3) << 24) | |
35 | #define MV64x60_WDC_CTL2_MASK (3 << 26) | |
36 | #define MV64x60_WDC_CTL2(val) ((val & 3) << 26) | |
37 | ||
38 | /* Flags bits */ | |
39 | #define MV64x60_WDOG_FLAG_OPENED 0 | |
40 | #define MV64x60_WDOG_FLAG_ENABLED 1 | |
41 | ||
42 | static unsigned long wdt_flags; | |
43 | static int wdt_status; | |
8a5cfa64 | 44 | static void __iomem *mv64x60_wdt_regs; |
3be10211 JC |
45 | static int mv64x60_wdt_timeout; |
46 | ||
47 | static void mv64x60_wdt_reg_write(u32 val) | |
48 | { | |
49 | /* Allow write only to CTL1 / CTL2 fields, retaining values in | |
50 | * other fields. | |
51 | */ | |
8a5cfa64 | 52 | u32 data = readl(mv64x60_wdt_regs + MV64x60_WDT_WDC_OFFSET); |
3be10211 JC |
53 | data &= ~(MV64x60_WDC_CTL1_MASK | MV64x60_WDC_CTL2_MASK); |
54 | data |= val; | |
8a5cfa64 | 55 | writel(data, mv64x60_wdt_regs + MV64x60_WDT_WDC_OFFSET); |
3be10211 JC |
56 | } |
57 | ||
58 | static void mv64x60_wdt_service(void) | |
59 | { | |
60 | /* Write 01 followed by 10 to CTL2 */ | |
61 | mv64x60_wdt_reg_write(MV64x60_WDC_CTL2(0x01)); | |
62 | mv64x60_wdt_reg_write(MV64x60_WDC_CTL2(0x02)); | |
63 | } | |
64 | ||
65 | static void mv64x60_wdt_handler_disable(void) | |
66 | { | |
67 | if (test_and_clear_bit(MV64x60_WDOG_FLAG_ENABLED, &wdt_flags)) { | |
68 | /* Write 01 followed by 10 to CTL1 */ | |
69 | mv64x60_wdt_reg_write(MV64x60_WDC_CTL1(0x01)); | |
70 | mv64x60_wdt_reg_write(MV64x60_WDC_CTL1(0x02)); | |
71 | printk(KERN_NOTICE "mv64x60_wdt: watchdog deactivated\n"); | |
72 | } | |
73 | } | |
74 | ||
75 | static void mv64x60_wdt_handler_enable(void) | |
76 | { | |
77 | if (!test_and_set_bit(MV64x60_WDOG_FLAG_ENABLED, &wdt_flags)) { | |
78 | /* Write 01 followed by 10 to CTL1 */ | |
79 | mv64x60_wdt_reg_write(MV64x60_WDC_CTL1(0x01)); | |
80 | mv64x60_wdt_reg_write(MV64x60_WDC_CTL1(0x02)); | |
81 | printk(KERN_NOTICE "mv64x60_wdt: watchdog activated\n"); | |
82 | } | |
83 | } | |
84 | ||
85 | static int mv64x60_wdt_open(struct inode *inode, struct file *file) | |
86 | { | |
87 | if (test_and_set_bit(MV64x60_WDOG_FLAG_OPENED, &wdt_flags)) | |
88 | return -EBUSY; | |
89 | ||
90 | mv64x60_wdt_service(); | |
91 | mv64x60_wdt_handler_enable(); | |
92 | ||
861e5137 | 93 | return nonseekable_open(inode, file); |
3be10211 JC |
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 | { | |
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: | |
264f0991 | 156 | if (put_user(mv64x60_wdt_timeout, (int __user *)argp)) |
3be10211 JC |
157 | return -EFAULT; |
158 | break; | |
159 | ||
160 | default: | |
795b89d2 | 161 | return -ENOTTY; |
3be10211 JC |
162 | } |
163 | ||
164 | return 0; | |
165 | } | |
166 | ||
62322d25 | 167 | static const struct file_operations mv64x60_wdt_fops = { |
3be10211 JC |
168 | .owner = THIS_MODULE, |
169 | .llseek = no_llseek, | |
170 | .write = mv64x60_wdt_write, | |
171 | .ioctl = mv64x60_wdt_ioctl, | |
172 | .open = mv64x60_wdt_open, | |
173 | .release = mv64x60_wdt_release, | |
174 | }; | |
175 | ||
176 | static struct miscdevice mv64x60_wdt_miscdev = { | |
177 | .minor = WATCHDOG_MINOR, | |
178 | .name = "watchdog", | |
179 | .fops = &mv64x60_wdt_fops, | |
180 | }; | |
181 | ||
3ae5eaec | 182 | static int __devinit mv64x60_wdt_probe(struct platform_device *dev) |
3be10211 | 183 | { |
3ae5eaec | 184 | struct mv64x60_wdt_pdata *pdata = dev->dev.platform_data; |
3be10211 | 185 | int bus_clk = 133; |
8a5cfa64 | 186 | struct resource *r; |
3be10211 JC |
187 | |
188 | mv64x60_wdt_timeout = 10; | |
189 | if (pdata) { | |
190 | mv64x60_wdt_timeout = pdata->timeout; | |
191 | bus_clk = pdata->bus_clk; | |
192 | } | |
193 | ||
8a5cfa64 DF |
194 | r = platform_get_resource(dev, IORESOURCE_MEM, 0); |
195 | if (!r) | |
196 | return -ENODEV; | |
197 | ||
198 | mv64x60_wdt_regs = ioremap(r->start, r->end - r->start + 1); | |
199 | if (mv64x60_wdt_regs == NULL) | |
200 | return -ENOMEM; | |
3be10211 JC |
201 | |
202 | writel((mv64x60_wdt_timeout * (bus_clk * 1000000)) >> 8, | |
8a5cfa64 | 203 | mv64x60_wdt_regs + MV64x60_WDT_WDC_OFFSET); |
3be10211 JC |
204 | |
205 | return misc_register(&mv64x60_wdt_miscdev); | |
206 | } | |
207 | ||
3ae5eaec | 208 | static int __devexit mv64x60_wdt_remove(struct platform_device *dev) |
3be10211 JC |
209 | { |
210 | misc_deregister(&mv64x60_wdt_miscdev); | |
211 | ||
212 | mv64x60_wdt_service(); | |
213 | mv64x60_wdt_handler_disable(); | |
214 | ||
8a5cfa64 DF |
215 | iounmap(mv64x60_wdt_regs); |
216 | ||
3be10211 JC |
217 | return 0; |
218 | } | |
219 | ||
3ae5eaec | 220 | static struct platform_driver mv64x60_wdt_driver = { |
3be10211 JC |
221 | .probe = mv64x60_wdt_probe, |
222 | .remove = __devexit_p(mv64x60_wdt_remove), | |
3ae5eaec RK |
223 | .driver = { |
224 | .owner = THIS_MODULE, | |
225 | .name = MV64x60_WDT_NAME, | |
226 | }, | |
3be10211 JC |
227 | }; |
228 | ||
3be10211 JC |
229 | static int __init mv64x60_wdt_init(void) |
230 | { | |
3be10211 JC |
231 | printk(KERN_INFO "MV64x60 watchdog driver\n"); |
232 | ||
422db8d2 | 233 | return platform_driver_register(&mv64x60_wdt_driver); |
3be10211 JC |
234 | } |
235 | ||
236 | static void __exit mv64x60_wdt_exit(void) | |
237 | { | |
3ae5eaec | 238 | platform_driver_unregister(&mv64x60_wdt_driver); |
3be10211 JC |
239 | } |
240 | ||
241 | module_init(mv64x60_wdt_init); | |
242 | module_exit(mv64x60_wdt_exit); | |
243 | ||
244 | MODULE_AUTHOR("James Chapman <jchapman@katalix.com>"); | |
245 | MODULE_DESCRIPTION("MV64x60 watchdog driver"); | |
246 | MODULE_LICENSE("GPL"); | |
247 | MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); |