diff options
author | Wim Van Sebroeck <wim@iguana.be> | 2007-08-17 04:38:02 -0400 |
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committer | Wim Van Sebroeck <wim@iguana.be> | 2007-10-18 06:39:03 -0400 |
commit | b7e04f8c61a46d742de23af5d7ca2b41b33e40ac (patch) | |
tree | c52a7ea568648e2d8ed0d423098b42298de2058b /drivers/watchdog/davinci_wdt.c | |
parent | d85714d81cc0408daddb68c10f7fd69eafe7c213 (diff) |
mv watchdog tree under drivers
move watchdog tree from drivers/char/watchdog to drivers/watchdog.
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
Diffstat (limited to 'drivers/watchdog/davinci_wdt.c')
-rw-r--r-- | drivers/watchdog/davinci_wdt.c | 281 |
1 files changed, 281 insertions, 0 deletions
diff --git a/drivers/watchdog/davinci_wdt.c b/drivers/watchdog/davinci_wdt.c new file mode 100644 index 000000000000..19db5302ba6e --- /dev/null +++ b/drivers/watchdog/davinci_wdt.c | |||
@@ -0,0 +1,281 @@ | |||
1 | /* | ||
2 | * drivers/char/watchdog/davinci_wdt.c | ||
3 | * | ||
4 | * Watchdog driver for DaVinci DM644x/DM646x processors | ||
5 | * | ||
6 | * Copyright (C) 2006 Texas Instruments. | ||
7 | * | ||
8 | * 2007 (c) MontaVista Software, Inc. This file is licensed under | ||
9 | * the terms of the GNU General Public License version 2. This program | ||
10 | * is licensed "as is" without any warranty of any kind, whether express | ||
11 | * or implied. | ||
12 | */ | ||
13 | |||
14 | #include <linux/module.h> | ||
15 | #include <linux/moduleparam.h> | ||
16 | #include <linux/types.h> | ||
17 | #include <linux/kernel.h> | ||
18 | #include <linux/fs.h> | ||
19 | #include <linux/miscdevice.h> | ||
20 | #include <linux/watchdog.h> | ||
21 | #include <linux/init.h> | ||
22 | #include <linux/bitops.h> | ||
23 | #include <linux/platform_device.h> | ||
24 | #include <linux/spinlock.h> | ||
25 | |||
26 | #include <asm/hardware.h> | ||
27 | #include <asm/uaccess.h> | ||
28 | #include <asm/io.h> | ||
29 | |||
30 | #define MODULE_NAME "DAVINCI-WDT: " | ||
31 | |||
32 | #define DEFAULT_HEARTBEAT 60 | ||
33 | #define MAX_HEARTBEAT 600 /* really the max margin is 264/27MHz*/ | ||
34 | |||
35 | /* Timer register set definition */ | ||
36 | #define PID12 (0x0) | ||
37 | #define EMUMGT (0x4) | ||
38 | #define TIM12 (0x10) | ||
39 | #define TIM34 (0x14) | ||
40 | #define PRD12 (0x18) | ||
41 | #define PRD34 (0x1C) | ||
42 | #define TCR (0x20) | ||
43 | #define TGCR (0x24) | ||
44 | #define WDTCR (0x28) | ||
45 | |||
46 | /* TCR bit definitions */ | ||
47 | #define ENAMODE12_DISABLED (0 << 6) | ||
48 | #define ENAMODE12_ONESHOT (1 << 6) | ||
49 | #define ENAMODE12_PERIODIC (2 << 6) | ||
50 | |||
51 | /* TGCR bit definitions */ | ||
52 | #define TIM12RS_UNRESET (1 << 0) | ||
53 | #define TIM34RS_UNRESET (1 << 1) | ||
54 | #define TIMMODE_64BIT_WDOG (2 << 2) | ||
55 | |||
56 | /* WDTCR bit definitions */ | ||
57 | #define WDEN (1 << 14) | ||
58 | #define WDFLAG (1 << 15) | ||
59 | #define WDKEY_SEQ0 (0xa5c6 << 16) | ||
60 | #define WDKEY_SEQ1 (0xda7e << 16) | ||
61 | |||
62 | static int heartbeat = DEFAULT_HEARTBEAT; | ||
63 | |||
64 | static spinlock_t io_lock; | ||
65 | static unsigned long wdt_status; | ||
66 | #define WDT_IN_USE 0 | ||
67 | #define WDT_OK_TO_CLOSE 1 | ||
68 | #define WDT_REGION_INITED 2 | ||
69 | #define WDT_DEVICE_INITED 3 | ||
70 | |||
71 | static struct resource *wdt_mem; | ||
72 | static void __iomem *wdt_base; | ||
73 | |||
74 | static void wdt_service(void) | ||
75 | { | ||
76 | spin_lock(&io_lock); | ||
77 | |||
78 | /* put watchdog in service state */ | ||
79 | davinci_writel(WDKEY_SEQ0, wdt_base + WDTCR); | ||
80 | /* put watchdog in active state */ | ||
81 | davinci_writel(WDKEY_SEQ1, wdt_base + WDTCR); | ||
82 | |||
83 | spin_unlock(&io_lock); | ||
84 | } | ||
85 | |||
86 | static void wdt_enable(void) | ||
87 | { | ||
88 | u32 tgcr; | ||
89 | u32 timer_margin; | ||
90 | |||
91 | spin_lock(&io_lock); | ||
92 | |||
93 | /* disable, internal clock source */ | ||
94 | davinci_writel(0, wdt_base + TCR); | ||
95 | /* reset timer, set mode to 64-bit watchdog, and unreset */ | ||
96 | davinci_writel(0, wdt_base + TGCR); | ||
97 | tgcr = TIMMODE_64BIT_WDOG | TIM12RS_UNRESET | TIM34RS_UNRESET; | ||
98 | davinci_writel(tgcr, wdt_base + TGCR); | ||
99 | /* clear counter regs */ | ||
100 | davinci_writel(0, wdt_base + TIM12); | ||
101 | davinci_writel(0, wdt_base + TIM34); | ||
102 | /* set timeout period */ | ||
103 | timer_margin = (((u64)heartbeat * CLOCK_TICK_RATE) & 0xffffffff); | ||
104 | davinci_writel(timer_margin, wdt_base + PRD12); | ||
105 | timer_margin = (((u64)heartbeat * CLOCK_TICK_RATE) >> 32); | ||
106 | davinci_writel(timer_margin, wdt_base + PRD34); | ||
107 | /* enable run continuously */ | ||
108 | davinci_writel(ENAMODE12_PERIODIC, wdt_base + TCR); | ||
109 | /* Once the WDT is in pre-active state write to | ||
110 | * TIM12, TIM34, PRD12, PRD34, TCR, TGCR, WDTCR are | ||
111 | * write protected (except for the WDKEY field) | ||
112 | */ | ||
113 | /* put watchdog in pre-active state */ | ||
114 | davinci_writel(WDKEY_SEQ0 | WDEN, wdt_base + WDTCR); | ||
115 | /* put watchdog in active state */ | ||
116 | davinci_writel(WDKEY_SEQ1 | WDEN, wdt_base + WDTCR); | ||
117 | |||
118 | spin_unlock(&io_lock); | ||
119 | } | ||
120 | |||
121 | static int davinci_wdt_open(struct inode *inode, struct file *file) | ||
122 | { | ||
123 | if (test_and_set_bit(WDT_IN_USE, &wdt_status)) | ||
124 | return -EBUSY; | ||
125 | |||
126 | wdt_enable(); | ||
127 | |||
128 | return nonseekable_open(inode, file); | ||
129 | } | ||
130 | |||
131 | static ssize_t | ||
132 | davinci_wdt_write(struct file *file, const char *data, size_t len, | ||
133 | loff_t *ppos) | ||
134 | { | ||
135 | if (len) | ||
136 | wdt_service(); | ||
137 | |||
138 | return len; | ||
139 | } | ||
140 | |||
141 | static struct watchdog_info ident = { | ||
142 | .options = WDIOF_KEEPALIVEPING, | ||
143 | .identity = "DaVinci Watchdog", | ||
144 | }; | ||
145 | |||
146 | static int | ||
147 | davinci_wdt_ioctl(struct inode *inode, struct file *file, unsigned int cmd, | ||
148 | unsigned long arg) | ||
149 | { | ||
150 | int ret = -ENOTTY; | ||
151 | |||
152 | switch (cmd) { | ||
153 | case WDIOC_GETSUPPORT: | ||
154 | ret = copy_to_user((struct watchdog_info *)arg, &ident, | ||
155 | sizeof(ident)) ? -EFAULT : 0; | ||
156 | break; | ||
157 | |||
158 | case WDIOC_GETSTATUS: | ||
159 | case WDIOC_GETBOOTSTATUS: | ||
160 | ret = put_user(0, (int *)arg); | ||
161 | break; | ||
162 | |||
163 | case WDIOC_GETTIMEOUT: | ||
164 | ret = put_user(heartbeat, (int *)arg); | ||
165 | break; | ||
166 | |||
167 | case WDIOC_KEEPALIVE: | ||
168 | wdt_service(); | ||
169 | ret = 0; | ||
170 | break; | ||
171 | } | ||
172 | return ret; | ||
173 | } | ||
174 | |||
175 | static int davinci_wdt_release(struct inode *inode, struct file *file) | ||
176 | { | ||
177 | wdt_service(); | ||
178 | clear_bit(WDT_IN_USE, &wdt_status); | ||
179 | |||
180 | return 0; | ||
181 | } | ||
182 | |||
183 | static const struct file_operations davinci_wdt_fops = { | ||
184 | .owner = THIS_MODULE, | ||
185 | .llseek = no_llseek, | ||
186 | .write = davinci_wdt_write, | ||
187 | .ioctl = davinci_wdt_ioctl, | ||
188 | .open = davinci_wdt_open, | ||
189 | .release = davinci_wdt_release, | ||
190 | }; | ||
191 | |||
192 | static struct miscdevice davinci_wdt_miscdev = { | ||
193 | .minor = WATCHDOG_MINOR, | ||
194 | .name = "watchdog", | ||
195 | .fops = &davinci_wdt_fops, | ||
196 | }; | ||
197 | |||
198 | static int davinci_wdt_probe(struct platform_device *pdev) | ||
199 | { | ||
200 | int ret = 0, size; | ||
201 | struct resource *res; | ||
202 | |||
203 | spin_lock_init(&io_lock); | ||
204 | |||
205 | if (heartbeat < 1 || heartbeat > MAX_HEARTBEAT) | ||
206 | heartbeat = DEFAULT_HEARTBEAT; | ||
207 | |||
208 | printk(KERN_INFO MODULE_NAME | ||
209 | "DaVinci Watchdog Timer: heartbeat %d sec\n", heartbeat); | ||
210 | |||
211 | res = platform_get_resource(pdev, IORESOURCE_MEM, 0); | ||
212 | if (res == NULL) { | ||
213 | printk(KERN_INFO MODULE_NAME | ||
214 | "failed to get memory region resource\n"); | ||
215 | return -ENOENT; | ||
216 | } | ||
217 | |||
218 | size = res->end - res->start + 1; | ||
219 | wdt_mem = request_mem_region(res->start, size, pdev->name); | ||
220 | |||
221 | if (wdt_mem == NULL) { | ||
222 | printk(KERN_INFO MODULE_NAME "failed to get memory region\n"); | ||
223 | return -ENOENT; | ||
224 | } | ||
225 | wdt_base = (void __iomem *)(res->start); | ||
226 | |||
227 | ret = misc_register(&davinci_wdt_miscdev); | ||
228 | if (ret < 0) { | ||
229 | printk(KERN_ERR MODULE_NAME "cannot register misc device\n"); | ||
230 | release_resource(wdt_mem); | ||
231 | kfree(wdt_mem); | ||
232 | } else { | ||
233 | set_bit(WDT_DEVICE_INITED, &wdt_status); | ||
234 | } | ||
235 | |||
236 | return ret; | ||
237 | } | ||
238 | |||
239 | static int davinci_wdt_remove(struct platform_device *pdev) | ||
240 | { | ||
241 | misc_deregister(&davinci_wdt_miscdev); | ||
242 | if (wdt_mem) { | ||
243 | release_resource(wdt_mem); | ||
244 | kfree(wdt_mem); | ||
245 | wdt_mem = NULL; | ||
246 | } | ||
247 | return 0; | ||
248 | } | ||
249 | |||
250 | static struct platform_driver platform_wdt_driver = { | ||
251 | .driver = { | ||
252 | .name = "watchdog", | ||
253 | }, | ||
254 | .probe = davinci_wdt_probe, | ||
255 | .remove = davinci_wdt_remove, | ||
256 | }; | ||
257 | |||
258 | static int __init davinci_wdt_init(void) | ||
259 | { | ||
260 | return platform_driver_register(&platform_wdt_driver); | ||
261 | } | ||
262 | |||
263 | static void __exit davinci_wdt_exit(void) | ||
264 | { | ||
265 | return platform_driver_unregister(&platform_wdt_driver); | ||
266 | } | ||
267 | |||
268 | module_init(davinci_wdt_init); | ||
269 | module_exit(davinci_wdt_exit); | ||
270 | |||
271 | MODULE_AUTHOR("Texas Instruments"); | ||
272 | MODULE_DESCRIPTION("DaVinci Watchdog Driver"); | ||
273 | |||
274 | module_param(heartbeat, int, 0); | ||
275 | MODULE_PARM_DESC(heartbeat, | ||
276 | "Watchdog heartbeat period in seconds from 1 to " | ||
277 | __MODULE_STRING(MAX_HEARTBEAT) ", default " | ||
278 | __MODULE_STRING(DEFAULT_HEARTBEAT)); | ||
279 | |||
280 | MODULE_LICENSE("GPL"); | ||
281 | MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); | ||