Commit | Line | Data |
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d0173278 | 1 | // SPDX-License-Identifier: GPL-2.0+ |
1da177e4 LT |
2 | /* |
3 | * Watchdog driver for the SA11x0/PXA2xx | |
4 | * | |
143a2e54 WVS |
5 | * (c) Copyright 2000 Oleg Drokin <green@crimea.edu> |
6 | * Based on SoftDog driver by Alan Cox <alan@lxorguk.ukuu.org.uk> | |
1da177e4 | 7 | * |
1da177e4 LT |
8 | * Neither Oleg Drokin nor iXcelerator.com admit liability nor provide |
9 | * warranty for any of this software. This material is provided | |
10 | * "AS-IS" and at no charge. | |
11 | * | |
12 | * (c) Copyright 2000 Oleg Drokin <green@crimea.edu> | |
13 | * | |
143a2e54 | 14 | * 27/11/2000 Initial release |
1da177e4 | 15 | */ |
27c766aa JP |
16 | |
17 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt | |
18 | ||
1da177e4 LT |
19 | #include <linux/module.h> |
20 | #include <linux/moduleparam.h> | |
6924089c | 21 | #include <linux/clk.h> |
1da177e4 LT |
22 | #include <linux/types.h> |
23 | #include <linux/kernel.h> | |
24 | #include <linux/fs.h> | |
25 | #include <linux/miscdevice.h> | |
26 | #include <linux/watchdog.h> | |
27 | #include <linux/init.h> | |
23019a73 | 28 | #include <linux/io.h> |
1977f032 | 29 | #include <linux/bitops.h> |
f19e0312 | 30 | #include <linux/uaccess.h> |
87c52578 | 31 | #include <linux/timex.h> |
1da177e4 LT |
32 | |
33 | #ifdef CONFIG_ARCH_PXA | |
5bf3df3f | 34 | #include <mach/regs-ost.h> |
1da177e4 LT |
35 | #endif |
36 | ||
afd2fc02 | 37 | #include <mach/reset.h> |
a09e64fb | 38 | #include <mach/hardware.h> |
1da177e4 | 39 | |
28a62385 | 40 | static unsigned long oscr_freq; |
1da177e4 | 41 | static unsigned long sa1100wdt_users; |
a6f052e3 | 42 | static unsigned int pre_margin; |
1da177e4 | 43 | static int boot_status; |
1da177e4 LT |
44 | |
45 | /* | |
46 | * Allow only one person to hold it open | |
47 | */ | |
48 | static int sa1100dog_open(struct inode *inode, struct file *file) | |
49 | { | |
f19e0312 | 50 | if (test_and_set_bit(1, &sa1100wdt_users)) |
1da177e4 LT |
51 | return -EBUSY; |
52 | ||
53 | /* Activate SA1100 Watchdog timer */ | |
3169663a RK |
54 | writel_relaxed(readl_relaxed(OSCR) + pre_margin, OSMR3); |
55 | writel_relaxed(OSSR_M3, OSSR); | |
56 | writel_relaxed(OWER_WME, OWER); | |
57 | writel_relaxed(readl_relaxed(OIER) | OIER_E3, OIER); | |
c5bf68fe | 58 | return stream_open(inode, file); |
1da177e4 LT |
59 | } |
60 | ||
61 | /* | |
9bbd0375 IC |
62 | * The watchdog cannot be disabled. |
63 | * | |
64 | * Previous comments suggested that turning off the interrupt by | |
65 | * clearing OIER[E3] would prevent the watchdog timing out but this | |
66 | * does not appear to be true (at least on the PXA255). | |
1da177e4 LT |
67 | */ |
68 | static int sa1100dog_release(struct inode *inode, struct file *file) | |
69 | { | |
27c766aa | 70 | pr_crit("Device closed - timer will not stop\n"); |
1da177e4 | 71 | clear_bit(1, &sa1100wdt_users); |
1da177e4 LT |
72 | return 0; |
73 | } | |
74 | ||
f19e0312 AC |
75 | static ssize_t sa1100dog_write(struct file *file, const char __user *data, |
76 | size_t len, loff_t *ppos) | |
1da177e4 | 77 | { |
9bbd0375 | 78 | if (len) |
1da177e4 | 79 | /* Refresh OSMR3 timer. */ |
3169663a | 80 | writel_relaxed(readl_relaxed(OSCR) + pre_margin, OSMR3); |
1da177e4 LT |
81 | return len; |
82 | } | |
83 | ||
f19e0312 AC |
84 | static const struct watchdog_info ident = { |
85 | .options = WDIOF_CARDRESET | WDIOF_SETTIMEOUT | |
86 | | WDIOF_KEEPALIVEPING, | |
9bbd0375 | 87 | .identity = "SA1100/PXA255 Watchdog", |
a6f052e3 | 88 | .firmware_version = 1, |
1da177e4 LT |
89 | }; |
90 | ||
f19e0312 AC |
91 | static long sa1100dog_ioctl(struct file *file, unsigned int cmd, |
92 | unsigned long arg) | |
1da177e4 | 93 | { |
795b89d2 | 94 | int ret = -ENOTTY; |
1da177e4 | 95 | int time; |
3a69e579 IC |
96 | void __user *argp = (void __user *)arg; |
97 | int __user *p = argp; | |
1da177e4 LT |
98 | |
99 | switch (cmd) { | |
100 | case WDIOC_GETSUPPORT: | |
3a69e579 | 101 | ret = copy_to_user(argp, &ident, |
1da177e4 LT |
102 | sizeof(ident)) ? -EFAULT : 0; |
103 | break; | |
104 | ||
105 | case WDIOC_GETSTATUS: | |
3a69e579 | 106 | ret = put_user(0, p); |
1da177e4 LT |
107 | break; |
108 | ||
109 | case WDIOC_GETBOOTSTATUS: | |
3a69e579 | 110 | ret = put_user(boot_status, p); |
1da177e4 LT |
111 | break; |
112 | ||
0c06090c | 113 | case WDIOC_KEEPALIVE: |
3169663a | 114 | writel_relaxed(readl_relaxed(OSCR) + pre_margin, OSMR3); |
0c06090c WVS |
115 | ret = 0; |
116 | break; | |
117 | ||
1da177e4 | 118 | case WDIOC_SETTIMEOUT: |
3a69e579 | 119 | ret = get_user(time, p); |
1da177e4 LT |
120 | if (ret) |
121 | break; | |
122 | ||
a6f052e3 | 123 | if (time <= 0 || (oscr_freq * (long long)time >= 0xffffffff)) { |
1da177e4 LT |
124 | ret = -EINVAL; |
125 | break; | |
126 | } | |
127 | ||
28a62385 | 128 | pre_margin = oscr_freq * time; |
3169663a | 129 | writel_relaxed(readl_relaxed(OSCR) + pre_margin, OSMR3); |
bd490f82 | 130 | fallthrough; |
1da177e4 LT |
131 | |
132 | case WDIOC_GETTIMEOUT: | |
28a62385 | 133 | ret = put_user(pre_margin / oscr_freq, p); |
1da177e4 | 134 | break; |
1da177e4 LT |
135 | } |
136 | return ret; | |
137 | } | |
138 | ||
f19e0312 | 139 | static const struct file_operations sa1100dog_fops = { |
1da177e4 LT |
140 | .owner = THIS_MODULE, |
141 | .llseek = no_llseek, | |
142 | .write = sa1100dog_write, | |
f19e0312 | 143 | .unlocked_ioctl = sa1100dog_ioctl, |
b6dfb247 | 144 | .compat_ioctl = compat_ptr_ioctl, |
1da177e4 LT |
145 | .open = sa1100dog_open, |
146 | .release = sa1100dog_release, | |
147 | }; | |
148 | ||
f19e0312 | 149 | static struct miscdevice sa1100dog_miscdev = { |
1da177e4 | 150 | .minor = WATCHDOG_MINOR, |
9bbd0375 | 151 | .name = "watchdog", |
1da177e4 LT |
152 | .fops = &sa1100dog_fops, |
153 | }; | |
154 | ||
155 | static int margin __initdata = 60; /* (secs) Default is 1 minute */ | |
6924089c | 156 | static struct clk *clk; |
1da177e4 LT |
157 | |
158 | static int __init sa1100dog_init(void) | |
159 | { | |
160 | int ret; | |
161 | ||
6924089c RJ |
162 | clk = clk_get(NULL, "OSTIMER0"); |
163 | if (IS_ERR(clk)) { | |
164 | pr_err("SA1100/PXA2xx Watchdog Timer: clock not found: %d\n", | |
165 | (int) PTR_ERR(clk)); | |
166 | return PTR_ERR(clk); | |
167 | } | |
168 | ||
169 | ret = clk_prepare_enable(clk); | |
170 | if (ret) { | |
171 | pr_err("SA1100/PXA2xx Watchdog Timer: clock failed to prepare+enable: %d\n", | |
172 | ret); | |
173 | goto err; | |
174 | } | |
175 | ||
176 | oscr_freq = clk_get_rate(clk); | |
28a62385 | 177 | |
1da177e4 LT |
178 | /* |
179 | * Read the reset status, and save it for later. If | |
180 | * we suspend, RCSR will be cleared, and the watchdog | |
181 | * reset reason will be lost. | |
182 | */ | |
214c6a7e EM |
183 | boot_status = (reset_status & RESET_STATUS_WATCHDOG) ? |
184 | WDIOF_CARDRESET : 0; | |
28a62385 | 185 | pre_margin = oscr_freq * margin; |
1da177e4 LT |
186 | |
187 | ret = misc_register(&sa1100dog_miscdev); | |
027d89d9 | 188 | if (ret == 0) { |
27c766aa JP |
189 | pr_info("SA1100/PXA2xx Watchdog Timer: timer margin %d sec\n", |
190 | margin); | |
027d89d9 VZ |
191 | return 0; |
192 | } | |
193 | ||
6924089c | 194 | clk_disable_unprepare(clk); |
027d89d9 | 195 | err: |
6924089c RJ |
196 | clk_put(clk); |
197 | return ret; | |
1da177e4 LT |
198 | } |
199 | ||
200 | static void __exit sa1100dog_exit(void) | |
201 | { | |
202 | misc_deregister(&sa1100dog_miscdev); | |
6924089c RJ |
203 | clk_disable_unprepare(clk); |
204 | clk_put(clk); | |
1da177e4 LT |
205 | } |
206 | ||
207 | module_init(sa1100dog_init); | |
208 | module_exit(sa1100dog_exit); | |
209 | ||
210 | MODULE_AUTHOR("Oleg Drokin <green@crimea.edu>"); | |
211 | MODULE_DESCRIPTION("SA1100/PXA2xx Watchdog"); | |
212 | ||
213 | module_param(margin, int, 0); | |
214 | MODULE_PARM_DESC(margin, "Watchdog margin in seconds (default 60s)"); | |
215 | ||
1da177e4 | 216 | MODULE_LICENSE("GPL"); |