Commit | Line | Data |
---|---|---|
88cce427 | 1 | /* |
9b9c63ff | 2 | * drivers/watchdog/m54xx_wdt.c |
88cce427 | 3 | * |
9b9c63ff | 4 | * Watchdog driver for ColdFire MCF547x & MCF548x processors |
88cce427 PDM |
5 | * Copyright 2010 (c) Philippe De Muyter <phdm@macqel.be> |
6 | * | |
7 | * Adapted from the IXP4xx watchdog driver, which carries these notices: | |
8 | * | |
9 | * Author: Deepak Saxena <dsaxena@plexity.net> | |
10 | * | |
11 | * Copyright 2004 (c) MontaVista, Software, Inc. | |
12 | * Based on sa1100 driver, Copyright (C) 2000 Oleg Drokin <green@crimea.edu> | |
13 | * | |
14 | * This file is licensed under the terms of the GNU General Public | |
15 | * License version 2. This program is licensed "as is" without any | |
16 | * warranty of any kind, whether express or implied. | |
17 | */ | |
18 | ||
27c766aa JP |
19 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
20 | ||
88cce427 PDM |
21 | #include <linux/module.h> |
22 | #include <linux/moduleparam.h> | |
23 | #include <linux/types.h> | |
24 | #include <linux/kernel.h> | |
25 | #include <linux/fs.h> | |
26 | #include <linux/miscdevice.h> | |
27 | #include <linux/watchdog.h> | |
28 | #include <linux/init.h> | |
29 | #include <linux/bitops.h> | |
30 | #include <linux/ioport.h> | |
31 | #include <linux/uaccess.h> | |
32 | ||
33 | #include <asm/coldfire.h> | |
9b9c63ff PDM |
34 | #include <asm/m54xxsim.h> |
35 | #include <asm/m54xxgpt.h> | |
88cce427 | 36 | |
86a1e189 | 37 | static bool nowayout = WATCHDOG_NOWAYOUT; |
88cce427 PDM |
38 | static unsigned int heartbeat = 30; /* (secs) Default is 0.5 minute */ |
39 | static unsigned long wdt_status; | |
40 | ||
41 | #define WDT_IN_USE 0 | |
42 | #define WDT_OK_TO_CLOSE 1 | |
43 | ||
44 | static void wdt_enable(void) | |
45 | { | |
46 | unsigned int gms0; | |
47 | ||
48 | /* preserve GPIO usage, if any */ | |
944c3d81 | 49 | gms0 = __raw_readl(MCF_GPT_GMS0); |
88cce427 PDM |
50 | if (gms0 & MCF_GPT_GMS_TMS_GPIO) |
51 | gms0 &= (MCF_GPT_GMS_TMS_GPIO | MCF_GPT_GMS_GPIO_MASK | |
52 | | MCF_GPT_GMS_OD); | |
53 | else | |
54 | gms0 = MCF_GPT_GMS_TMS_GPIO | MCF_GPT_GMS_OD; | |
944c3d81 | 55 | __raw_writel(gms0, MCF_GPT_GMS0); |
88cce427 | 56 | __raw_writel(MCF_GPT_GCIR_PRE(heartbeat*(MCF_BUSCLK/0xffff)) | |
944c3d81 | 57 | MCF_GPT_GCIR_CNT(0xffff), MCF_GPT_GCIR0); |
88cce427 | 58 | gms0 |= MCF_GPT_GMS_OCPW(0xA5) | MCF_GPT_GMS_WDEN | MCF_GPT_GMS_CE; |
944c3d81 | 59 | __raw_writel(gms0, MCF_GPT_GMS0); |
88cce427 PDM |
60 | } |
61 | ||
62 | static void wdt_disable(void) | |
63 | { | |
64 | unsigned int gms0; | |
65 | ||
66 | /* disable watchdog */ | |
944c3d81 | 67 | gms0 = __raw_readl(MCF_GPT_GMS0); |
88cce427 | 68 | gms0 &= ~(MCF_GPT_GMS_WDEN | MCF_GPT_GMS_CE); |
944c3d81 | 69 | __raw_writel(gms0, MCF_GPT_GMS0); |
88cce427 PDM |
70 | } |
71 | ||
72 | static void wdt_keepalive(void) | |
73 | { | |
74 | unsigned int gms0; | |
75 | ||
944c3d81 | 76 | gms0 = __raw_readl(MCF_GPT_GMS0); |
88cce427 | 77 | gms0 |= MCF_GPT_GMS_OCPW(0xA5); |
944c3d81 | 78 | __raw_writel(gms0, MCF_GPT_GMS0); |
88cce427 PDM |
79 | } |
80 | ||
9b9c63ff | 81 | static int m54xx_wdt_open(struct inode *inode, struct file *file) |
88cce427 PDM |
82 | { |
83 | if (test_and_set_bit(WDT_IN_USE, &wdt_status)) | |
84 | return -EBUSY; | |
85 | ||
86 | clear_bit(WDT_OK_TO_CLOSE, &wdt_status); | |
87 | wdt_enable(); | |
88 | return nonseekable_open(inode, file); | |
89 | } | |
90 | ||
9b9c63ff | 91 | static ssize_t m54xx_wdt_write(struct file *file, const char *data, |
88cce427 PDM |
92 | size_t len, loff_t *ppos) |
93 | { | |
94 | if (len) { | |
95 | if (!nowayout) { | |
96 | size_t i; | |
97 | ||
98 | clear_bit(WDT_OK_TO_CLOSE, &wdt_status); | |
99 | ||
100 | for (i = 0; i != len; i++) { | |
101 | char c; | |
102 | ||
103 | if (get_user(c, data + i)) | |
104 | return -EFAULT; | |
105 | if (c == 'V') | |
106 | set_bit(WDT_OK_TO_CLOSE, &wdt_status); | |
107 | } | |
108 | } | |
109 | wdt_keepalive(); | |
110 | } | |
111 | return len; | |
112 | } | |
113 | ||
114 | static const struct watchdog_info ident = { | |
115 | .options = WDIOF_MAGICCLOSE | WDIOF_SETTIMEOUT | | |
116 | WDIOF_KEEPALIVEPING, | |
9b9c63ff | 117 | .identity = "Coldfire M54xx Watchdog", |
88cce427 PDM |
118 | }; |
119 | ||
9b9c63ff | 120 | static long m54xx_wdt_ioctl(struct file *file, unsigned int cmd, |
88cce427 PDM |
121 | unsigned long arg) |
122 | { | |
123 | int ret = -ENOTTY; | |
124 | int time; | |
125 | ||
126 | switch (cmd) { | |
127 | case WDIOC_GETSUPPORT: | |
128 | ret = copy_to_user((struct watchdog_info *)arg, &ident, | |
129 | sizeof(ident)) ? -EFAULT : 0; | |
130 | break; | |
131 | ||
132 | case WDIOC_GETSTATUS: | |
133 | ret = put_user(0, (int *)arg); | |
134 | break; | |
135 | ||
136 | case WDIOC_GETBOOTSTATUS: | |
137 | ret = put_user(0, (int *)arg); | |
138 | break; | |
139 | ||
140 | case WDIOC_KEEPALIVE: | |
141 | wdt_keepalive(); | |
142 | ret = 0; | |
143 | break; | |
144 | ||
145 | case WDIOC_SETTIMEOUT: | |
146 | ret = get_user(time, (int *)arg); | |
147 | if (ret) | |
148 | break; | |
149 | ||
150 | if (time <= 0 || time > 30) { | |
151 | ret = -EINVAL; | |
152 | break; | |
153 | } | |
154 | ||
155 | heartbeat = time; | |
156 | wdt_enable(); | |
157 | /* Fall through */ | |
158 | ||
159 | case WDIOC_GETTIMEOUT: | |
160 | ret = put_user(heartbeat, (int *)arg); | |
161 | break; | |
162 | } | |
163 | return ret; | |
164 | } | |
165 | ||
9b9c63ff | 166 | static int m54xx_wdt_release(struct inode *inode, struct file *file) |
88cce427 PDM |
167 | { |
168 | if (test_bit(WDT_OK_TO_CLOSE, &wdt_status)) | |
169 | wdt_disable(); | |
170 | else { | |
27c766aa | 171 | pr_crit("Device closed unexpectedly - timer will not stop\n"); |
88cce427 PDM |
172 | wdt_keepalive(); |
173 | } | |
174 | clear_bit(WDT_IN_USE, &wdt_status); | |
175 | clear_bit(WDT_OK_TO_CLOSE, &wdt_status); | |
176 | ||
177 | return 0; | |
178 | } | |
179 | ||
180 | ||
9b9c63ff | 181 | static const struct file_operations m54xx_wdt_fops = { |
88cce427 PDM |
182 | .owner = THIS_MODULE, |
183 | .llseek = no_llseek, | |
9b9c63ff PDM |
184 | .write = m54xx_wdt_write, |
185 | .unlocked_ioctl = m54xx_wdt_ioctl, | |
186 | .open = m54xx_wdt_open, | |
187 | .release = m54xx_wdt_release, | |
88cce427 PDM |
188 | }; |
189 | ||
9b9c63ff | 190 | static struct miscdevice m54xx_wdt_miscdev = { |
88cce427 PDM |
191 | .minor = WATCHDOG_MINOR, |
192 | .name = "watchdog", | |
9b9c63ff | 193 | .fops = &m54xx_wdt_fops, |
88cce427 PDM |
194 | }; |
195 | ||
9b9c63ff | 196 | static int __init m54xx_wdt_init(void) |
88cce427 | 197 | { |
944c3d81 | 198 | if (!request_mem_region(MCF_GPT_GCIR0, 4, "Coldfire M54xx Watchdog")) { |
27c766aa | 199 | pr_warn("I/O region busy\n"); |
88cce427 PDM |
200 | return -EBUSY; |
201 | } | |
27c766aa | 202 | pr_info("driver is loaded\n"); |
88cce427 | 203 | |
9b9c63ff | 204 | return misc_register(&m54xx_wdt_miscdev); |
88cce427 PDM |
205 | } |
206 | ||
9b9c63ff | 207 | static void __exit m54xx_wdt_exit(void) |
88cce427 | 208 | { |
9b9c63ff | 209 | misc_deregister(&m54xx_wdt_miscdev); |
944c3d81 | 210 | release_mem_region(MCF_GPT_GCIR0, 4); |
88cce427 PDM |
211 | } |
212 | ||
9b9c63ff PDM |
213 | module_init(m54xx_wdt_init); |
214 | module_exit(m54xx_wdt_exit); | |
88cce427 PDM |
215 | |
216 | MODULE_AUTHOR("Philippe De Muyter <phdm@macqel.be>"); | |
9b9c63ff | 217 | MODULE_DESCRIPTION("Coldfire M54xx Watchdog"); |
88cce427 PDM |
218 | |
219 | module_param(heartbeat, int, 0); | |
220 | MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat in seconds (default 30s)"); | |
221 | ||
86a1e189 | 222 | module_param(nowayout, bool, 0); |
88cce427 PDM |
223 | MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started"); |
224 | ||
225 | MODULE_LICENSE("GPL"); | |
226 | MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); |