diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /drivers/misc/hdpuftrs/hdpu_cpustate.c |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'drivers/misc/hdpuftrs/hdpu_cpustate.c')
-rw-r--r-- | drivers/misc/hdpuftrs/hdpu_cpustate.c | 234 |
1 files changed, 234 insertions, 0 deletions
diff --git a/drivers/misc/hdpuftrs/hdpu_cpustate.c b/drivers/misc/hdpuftrs/hdpu_cpustate.c new file mode 100644 index 000000000000..7501fab349e4 --- /dev/null +++ b/drivers/misc/hdpuftrs/hdpu_cpustate.c | |||
@@ -0,0 +1,234 @@ | |||
1 | /* | ||
2 | * Sky CPU State Driver | ||
3 | * | ||
4 | * Copyright (C) 2002 Brian Waite | ||
5 | * | ||
6 | * This driver allows use of the CPU state bits | ||
7 | * It exports the /dev/sky_cpustate and also | ||
8 | * /proc/sky_cpustate pseudo-file for status information. | ||
9 | * | ||
10 | * This program is free software; you can redistribute it and/or | ||
11 | * modify it under the terms of the GNU General Public License | ||
12 | * as published by the Free Software Foundation; either version | ||
13 | * 2 of the License, or (at your option) any later version. | ||
14 | * | ||
15 | */ | ||
16 | |||
17 | #include <linux/version.h> | ||
18 | #include <linux/module.h> | ||
19 | #include <linux/kernel.h> | ||
20 | #include <linux/spinlock.h> | ||
21 | #include <linux/miscdevice.h> | ||
22 | #include <linux/pci.h> | ||
23 | #include <linux/proc_fs.h> | ||
24 | #include <linux/device.h> | ||
25 | #include <asm/uaccess.h> | ||
26 | #include <linux/hdpu_features.h> | ||
27 | |||
28 | #define SKY_CPUSTATE_VERSION "1.1" | ||
29 | |||
30 | static int hdpu_cpustate_probe(struct device *ddev); | ||
31 | static int hdpu_cpustate_remove(struct device *ddev); | ||
32 | |||
33 | struct cpustate_t cpustate; | ||
34 | |||
35 | static int cpustate_get_ref(int excl) | ||
36 | { | ||
37 | |||
38 | int retval = -EBUSY; | ||
39 | |||
40 | spin_lock(&cpustate.lock); | ||
41 | |||
42 | if (cpustate.excl) | ||
43 | goto out_busy; | ||
44 | |||
45 | if (excl) { | ||
46 | if (cpustate.open_count) | ||
47 | goto out_busy; | ||
48 | cpustate.excl = 1; | ||
49 | } | ||
50 | |||
51 | cpustate.open_count++; | ||
52 | retval = 0; | ||
53 | |||
54 | out_busy: | ||
55 | spin_unlock(&cpustate.lock); | ||
56 | return retval; | ||
57 | } | ||
58 | |||
59 | static int cpustate_free_ref(void) | ||
60 | { | ||
61 | |||
62 | spin_lock(&cpustate.lock); | ||
63 | |||
64 | cpustate.excl = 0; | ||
65 | cpustate.open_count--; | ||
66 | |||
67 | spin_unlock(&cpustate.lock); | ||
68 | return 0; | ||
69 | } | ||
70 | |||
71 | unsigned char cpustate_get_state(void) | ||
72 | { | ||
73 | |||
74 | return cpustate.cached_val; | ||
75 | } | ||
76 | |||
77 | void cpustate_set_state(unsigned char new_state) | ||
78 | { | ||
79 | unsigned int state = (new_state << 21); | ||
80 | |||
81 | #ifdef DEBUG_CPUSTATE | ||
82 | printk("CPUSTATE -> 0x%x\n", new_state); | ||
83 | #endif | ||
84 | spin_lock(&cpustate.lock); | ||
85 | cpustate.cached_val = new_state; | ||
86 | writel((0xff << 21), cpustate.clr_addr); | ||
87 | writel(state, cpustate.set_addr); | ||
88 | spin_unlock(&cpustate.lock); | ||
89 | } | ||
90 | |||
91 | /* | ||
92 | * Now all the various file operations that we export. | ||
93 | */ | ||
94 | |||
95 | static ssize_t cpustate_read(struct file *file, char *buf, | ||
96 | size_t count, loff_t * ppos) | ||
97 | { | ||
98 | unsigned char data; | ||
99 | |||
100 | if (count < 0) | ||
101 | return -EFAULT; | ||
102 | if (count == 0) | ||
103 | return 0; | ||
104 | |||
105 | data = cpustate_get_state(); | ||
106 | if (copy_to_user(buf, &data, sizeof(unsigned char))) | ||
107 | return -EFAULT; | ||
108 | return sizeof(unsigned char); | ||
109 | } | ||
110 | |||
111 | static ssize_t cpustate_write(struct file *file, const char *buf, | ||
112 | size_t count, loff_t * ppos) | ||
113 | { | ||
114 | unsigned char data; | ||
115 | |||
116 | if (count < 0) | ||
117 | return -EFAULT; | ||
118 | |||
119 | if (count == 0) | ||
120 | return 0; | ||
121 | |||
122 | if (copy_from_user((unsigned char *)&data, buf, sizeof(unsigned char))) | ||
123 | return -EFAULT; | ||
124 | |||
125 | cpustate_set_state(data); | ||
126 | return sizeof(unsigned char); | ||
127 | } | ||
128 | |||
129 | static int cpustate_open(struct inode *inode, struct file *file) | ||
130 | { | ||
131 | return cpustate_get_ref((file->f_flags & O_EXCL)); | ||
132 | } | ||
133 | |||
134 | static int cpustate_release(struct inode *inode, struct file *file) | ||
135 | { | ||
136 | return cpustate_free_ref(); | ||
137 | } | ||
138 | |||
139 | /* | ||
140 | * Info exported via "/proc/sky_cpustate". | ||
141 | */ | ||
142 | static int cpustate_read_proc(char *page, char **start, off_t off, | ||
143 | int count, int *eof, void *data) | ||
144 | { | ||
145 | char *p = page; | ||
146 | int len = 0; | ||
147 | |||
148 | p += sprintf(p, "CPU State: %04x\n", cpustate_get_state()); | ||
149 | len = p - page; | ||
150 | |||
151 | if (len <= off + count) | ||
152 | *eof = 1; | ||
153 | *start = page + off; | ||
154 | len -= off; | ||
155 | if (len > count) | ||
156 | len = count; | ||
157 | if (len < 0) | ||
158 | len = 0; | ||
159 | return len; | ||
160 | } | ||
161 | |||
162 | static struct device_driver hdpu_cpustate_driver = { | ||
163 | .name = HDPU_CPUSTATE_NAME, | ||
164 | .bus = &platform_bus_type, | ||
165 | .probe = hdpu_cpustate_probe, | ||
166 | .remove = hdpu_cpustate_remove, | ||
167 | }; | ||
168 | |||
169 | /* | ||
170 | * The various file operations we support. | ||
171 | */ | ||
172 | static struct file_operations cpustate_fops = { | ||
173 | owner:THIS_MODULE, | ||
174 | open:cpustate_open, | ||
175 | release:cpustate_release, | ||
176 | read:cpustate_read, | ||
177 | write:cpustate_write, | ||
178 | fasync:NULL, | ||
179 | poll:NULL, | ||
180 | ioctl:NULL, | ||
181 | llseek:no_llseek, | ||
182 | |||
183 | }; | ||
184 | |||
185 | static struct miscdevice cpustate_dev = { | ||
186 | MISC_DYNAMIC_MINOR, | ||
187 | "sky_cpustate", | ||
188 | &cpustate_fops | ||
189 | }; | ||
190 | |||
191 | static int hdpu_cpustate_probe(struct device *ddev) | ||
192 | { | ||
193 | struct platform_device *pdev = to_platform_device(ddev); | ||
194 | struct resource *res; | ||
195 | |||
196 | res = platform_get_resource(pdev, IORESOURCE_MEM, 0); | ||
197 | cpustate.set_addr = (unsigned long *)res->start; | ||
198 | cpustate.clr_addr = (unsigned long *)res->end - 1; | ||
199 | |||
200 | misc_register(&cpustate_dev); | ||
201 | create_proc_read_entry("sky_cpustate", 0, 0, cpustate_read_proc, NULL); | ||
202 | |||
203 | printk(KERN_INFO "Sky CPU State Driver v" SKY_CPUSTATE_VERSION "\n"); | ||
204 | return 0; | ||
205 | } | ||
206 | static int hdpu_cpustate_remove(struct device *ddev) | ||
207 | { | ||
208 | |||
209 | cpustate.set_addr = 0; | ||
210 | cpustate.clr_addr = 0; | ||
211 | |||
212 | remove_proc_entry("sky_cpustate", NULL); | ||
213 | misc_deregister(&cpustate_dev); | ||
214 | return 0; | ||
215 | |||
216 | } | ||
217 | |||
218 | static int __init cpustate_init(void) | ||
219 | { | ||
220 | int rc; | ||
221 | rc = driver_register(&hdpu_cpustate_driver); | ||
222 | return rc; | ||
223 | } | ||
224 | |||
225 | static void __exit cpustate_exit(void) | ||
226 | { | ||
227 | driver_unregister(&hdpu_cpustate_driver); | ||
228 | } | ||
229 | |||
230 | module_init(cpustate_init); | ||
231 | module_exit(cpustate_exit); | ||
232 | |||
233 | MODULE_AUTHOR("Brian Waite"); | ||
234 | MODULE_LICENSE("GPL"); | ||