diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
---|---|---|
committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /arch/i386/kernel/cpu/cpufreq/elanfreq.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 'arch/i386/kernel/cpu/cpufreq/elanfreq.c')
-rw-r--r-- | arch/i386/kernel/cpu/cpufreq/elanfreq.c | 312 |
1 files changed, 312 insertions, 0 deletions
diff --git a/arch/i386/kernel/cpu/cpufreq/elanfreq.c b/arch/i386/kernel/cpu/cpufreq/elanfreq.c new file mode 100644 index 000000000000..3f7caa4ae6d6 --- /dev/null +++ b/arch/i386/kernel/cpu/cpufreq/elanfreq.c | |||
@@ -0,0 +1,312 @@ | |||
1 | /* | ||
2 | * elanfreq: cpufreq driver for the AMD ELAN family | ||
3 | * | ||
4 | * (c) Copyright 2002 Robert Schwebel <r.schwebel@pengutronix.de> | ||
5 | * | ||
6 | * Parts of this code are (c) Sven Geggus <sven@geggus.net> | ||
7 | * | ||
8 | * All Rights Reserved. | ||
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 | * 2002-02-13: - initial revision for 2.4.18-pre9 by Robert Schwebel | ||
16 | * | ||
17 | */ | ||
18 | |||
19 | #include <linux/kernel.h> | ||
20 | #include <linux/module.h> | ||
21 | #include <linux/init.h> | ||
22 | |||
23 | #include <linux/slab.h> | ||
24 | #include <linux/delay.h> | ||
25 | #include <linux/cpufreq.h> | ||
26 | |||
27 | #include <asm/msr.h> | ||
28 | #include <asm/timex.h> | ||
29 | #include <asm/io.h> | ||
30 | |||
31 | #define REG_CSCIR 0x22 /* Chip Setup and Control Index Register */ | ||
32 | #define REG_CSCDR 0x23 /* Chip Setup and Control Data Register */ | ||
33 | |||
34 | /* Module parameter */ | ||
35 | static int max_freq; | ||
36 | |||
37 | struct s_elan_multiplier { | ||
38 | int clock; /* frequency in kHz */ | ||
39 | int val40h; /* PMU Force Mode register */ | ||
40 | int val80h; /* CPU Clock Speed Register */ | ||
41 | }; | ||
42 | |||
43 | /* | ||
44 | * It is important that the frequencies | ||
45 | * are listed in ascending order here! | ||
46 | */ | ||
47 | struct s_elan_multiplier elan_multiplier[] = { | ||
48 | {1000, 0x02, 0x18}, | ||
49 | {2000, 0x02, 0x10}, | ||
50 | {4000, 0x02, 0x08}, | ||
51 | {8000, 0x00, 0x00}, | ||
52 | {16000, 0x00, 0x02}, | ||
53 | {33000, 0x00, 0x04}, | ||
54 | {66000, 0x01, 0x04}, | ||
55 | {99000, 0x01, 0x05} | ||
56 | }; | ||
57 | |||
58 | static struct cpufreq_frequency_table elanfreq_table[] = { | ||
59 | {0, 1000}, | ||
60 | {1, 2000}, | ||
61 | {2, 4000}, | ||
62 | {3, 8000}, | ||
63 | {4, 16000}, | ||
64 | {5, 33000}, | ||
65 | {6, 66000}, | ||
66 | {7, 99000}, | ||
67 | {0, CPUFREQ_TABLE_END}, | ||
68 | }; | ||
69 | |||
70 | |||
71 | /** | ||
72 | * elanfreq_get_cpu_frequency: determine current cpu speed | ||
73 | * | ||
74 | * Finds out at which frequency the CPU of the Elan SOC runs | ||
75 | * at the moment. Frequencies from 1 to 33 MHz are generated | ||
76 | * the normal way, 66 and 99 MHz are called "Hyperspeed Mode" | ||
77 | * and have the rest of the chip running with 33 MHz. | ||
78 | */ | ||
79 | |||
80 | static unsigned int elanfreq_get_cpu_frequency(unsigned int cpu) | ||
81 | { | ||
82 | u8 clockspeed_reg; /* Clock Speed Register */ | ||
83 | |||
84 | local_irq_disable(); | ||
85 | outb_p(0x80,REG_CSCIR); | ||
86 | clockspeed_reg = inb_p(REG_CSCDR); | ||
87 | local_irq_enable(); | ||
88 | |||
89 | if ((clockspeed_reg & 0xE0) == 0xE0) { return 0; } | ||
90 | |||
91 | /* Are we in CPU clock multiplied mode (66/99 MHz)? */ | ||
92 | if ((clockspeed_reg & 0xE0) == 0xC0) { | ||
93 | if ((clockspeed_reg & 0x01) == 0) { | ||
94 | return 66000; | ||
95 | } else { | ||
96 | return 99000; | ||
97 | } | ||
98 | } | ||
99 | |||
100 | /* 33 MHz is not 32 MHz... */ | ||
101 | if ((clockspeed_reg & 0xE0)==0xA0) | ||
102 | return 33000; | ||
103 | |||
104 | return ((1<<((clockspeed_reg & 0xE0) >> 5)) * 1000); | ||
105 | } | ||
106 | |||
107 | |||
108 | /** | ||
109 | * elanfreq_set_cpu_frequency: Change the CPU core frequency | ||
110 | * @cpu: cpu number | ||
111 | * @freq: frequency in kHz | ||
112 | * | ||
113 | * This function takes a frequency value and changes the CPU frequency | ||
114 | * according to this. Note that the frequency has to be checked by | ||
115 | * elanfreq_validatespeed() for correctness! | ||
116 | * | ||
117 | * There is no return value. | ||
118 | */ | ||
119 | |||
120 | static void elanfreq_set_cpu_state (unsigned int state) { | ||
121 | |||
122 | struct cpufreq_freqs freqs; | ||
123 | |||
124 | freqs.old = elanfreq_get_cpu_frequency(0); | ||
125 | freqs.new = elan_multiplier[state].clock; | ||
126 | freqs.cpu = 0; /* elanfreq.c is UP only driver */ | ||
127 | |||
128 | cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE); | ||
129 | |||
130 | printk(KERN_INFO "elanfreq: attempting to set frequency to %i kHz\n",elan_multiplier[state].clock); | ||
131 | |||
132 | |||
133 | /* | ||
134 | * Access to the Elan's internal registers is indexed via | ||
135 | * 0x22: Chip Setup & Control Register Index Register (CSCI) | ||
136 | * 0x23: Chip Setup & Control Register Data Register (CSCD) | ||
137 | * | ||
138 | */ | ||
139 | |||
140 | /* | ||
141 | * 0x40 is the Power Management Unit's Force Mode Register. | ||
142 | * Bit 6 enables Hyperspeed Mode (66/100 MHz core frequency) | ||
143 | */ | ||
144 | |||
145 | local_irq_disable(); | ||
146 | outb_p(0x40,REG_CSCIR); /* Disable hyperspeed mode */ | ||
147 | outb_p(0x00,REG_CSCDR); | ||
148 | local_irq_enable(); /* wait till internal pipelines and */ | ||
149 | udelay(1000); /* buffers have cleaned up */ | ||
150 | |||
151 | local_irq_disable(); | ||
152 | |||
153 | /* now, set the CPU clock speed register (0x80) */ | ||
154 | outb_p(0x80,REG_CSCIR); | ||
155 | outb_p(elan_multiplier[state].val80h,REG_CSCDR); | ||
156 | |||
157 | /* now, the hyperspeed bit in PMU Force Mode Register (0x40) */ | ||
158 | outb_p(0x40,REG_CSCIR); | ||
159 | outb_p(elan_multiplier[state].val40h,REG_CSCDR); | ||
160 | udelay(10000); | ||
161 | local_irq_enable(); | ||
162 | |||
163 | cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE); | ||
164 | }; | ||
165 | |||
166 | |||
167 | /** | ||
168 | * elanfreq_validatespeed: test if frequency range is valid | ||
169 | * @policy: the policy to validate | ||
170 | * | ||
171 | * This function checks if a given frequency range in kHz is valid | ||
172 | * for the hardware supported by the driver. | ||
173 | */ | ||
174 | |||
175 | static int elanfreq_verify (struct cpufreq_policy *policy) | ||
176 | { | ||
177 | return cpufreq_frequency_table_verify(policy, &elanfreq_table[0]); | ||
178 | } | ||
179 | |||
180 | static int elanfreq_target (struct cpufreq_policy *policy, | ||
181 | unsigned int target_freq, | ||
182 | unsigned int relation) | ||
183 | { | ||
184 | unsigned int newstate = 0; | ||
185 | |||
186 | if (cpufreq_frequency_table_target(policy, &elanfreq_table[0], target_freq, relation, &newstate)) | ||
187 | return -EINVAL; | ||
188 | |||
189 | elanfreq_set_cpu_state(newstate); | ||
190 | |||
191 | return 0; | ||
192 | } | ||
193 | |||
194 | |||
195 | /* | ||
196 | * Module init and exit code | ||
197 | */ | ||
198 | |||
199 | static int elanfreq_cpu_init(struct cpufreq_policy *policy) | ||
200 | { | ||
201 | struct cpuinfo_x86 *c = cpu_data; | ||
202 | unsigned int i; | ||
203 | int result; | ||
204 | |||
205 | /* capability check */ | ||
206 | if ((c->x86_vendor != X86_VENDOR_AMD) || | ||
207 | (c->x86 != 4) || (c->x86_model!=10)) | ||
208 | return -ENODEV; | ||
209 | |||
210 | /* max freq */ | ||
211 | if (!max_freq) | ||
212 | max_freq = elanfreq_get_cpu_frequency(0); | ||
213 | |||
214 | /* table init */ | ||
215 | for (i=0; (elanfreq_table[i].frequency != CPUFREQ_TABLE_END); i++) { | ||
216 | if (elanfreq_table[i].frequency > max_freq) | ||
217 | elanfreq_table[i].frequency = CPUFREQ_ENTRY_INVALID; | ||
218 | } | ||
219 | |||
220 | /* cpuinfo and default policy values */ | ||
221 | policy->governor = CPUFREQ_DEFAULT_GOVERNOR; | ||
222 | policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL; | ||
223 | policy->cur = elanfreq_get_cpu_frequency(0); | ||
224 | |||
225 | result = cpufreq_frequency_table_cpuinfo(policy, elanfreq_table); | ||
226 | if (result) | ||
227 | return (result); | ||
228 | |||
229 | cpufreq_frequency_table_get_attr(elanfreq_table, policy->cpu); | ||
230 | |||
231 | return 0; | ||
232 | } | ||
233 | |||
234 | |||
235 | static int elanfreq_cpu_exit(struct cpufreq_policy *policy) | ||
236 | { | ||
237 | cpufreq_frequency_table_put_attr(policy->cpu); | ||
238 | return 0; | ||
239 | } | ||
240 | |||
241 | |||
242 | #ifndef MODULE | ||
243 | /** | ||
244 | * elanfreq_setup - elanfreq command line parameter parsing | ||
245 | * | ||
246 | * elanfreq command line parameter. Use: | ||
247 | * elanfreq=66000 | ||
248 | * to set the maximum CPU frequency to 66 MHz. Note that in | ||
249 | * case you do not give this boot parameter, the maximum | ||
250 | * frequency will fall back to _current_ CPU frequency which | ||
251 | * might be lower. If you build this as a module, use the | ||
252 | * max_freq module parameter instead. | ||
253 | */ | ||
254 | static int __init elanfreq_setup(char *str) | ||
255 | { | ||
256 | max_freq = simple_strtoul(str, &str, 0); | ||
257 | printk(KERN_WARNING "You're using the deprecated elanfreq command line option. Use elanfreq.max_freq instead, please!\n"); | ||
258 | return 1; | ||
259 | } | ||
260 | __setup("elanfreq=", elanfreq_setup); | ||
261 | #endif | ||
262 | |||
263 | |||
264 | static struct freq_attr* elanfreq_attr[] = { | ||
265 | &cpufreq_freq_attr_scaling_available_freqs, | ||
266 | NULL, | ||
267 | }; | ||
268 | |||
269 | |||
270 | static struct cpufreq_driver elanfreq_driver = { | ||
271 | .get = elanfreq_get_cpu_frequency, | ||
272 | .verify = elanfreq_verify, | ||
273 | .target = elanfreq_target, | ||
274 | .init = elanfreq_cpu_init, | ||
275 | .exit = elanfreq_cpu_exit, | ||
276 | .name = "elanfreq", | ||
277 | .owner = THIS_MODULE, | ||
278 | .attr = elanfreq_attr, | ||
279 | }; | ||
280 | |||
281 | |||
282 | static int __init elanfreq_init(void) | ||
283 | { | ||
284 | struct cpuinfo_x86 *c = cpu_data; | ||
285 | |||
286 | /* Test if we have the right hardware */ | ||
287 | if ((c->x86_vendor != X86_VENDOR_AMD) || | ||
288 | (c->x86 != 4) || (c->x86_model!=10)) | ||
289 | { | ||
290 | printk(KERN_INFO "elanfreq: error: no Elan processor found!\n"); | ||
291 | return -ENODEV; | ||
292 | } | ||
293 | |||
294 | return cpufreq_register_driver(&elanfreq_driver); | ||
295 | } | ||
296 | |||
297 | |||
298 | static void __exit elanfreq_exit(void) | ||
299 | { | ||
300 | cpufreq_unregister_driver(&elanfreq_driver); | ||
301 | } | ||
302 | |||
303 | |||
304 | module_param (max_freq, int, 0444); | ||
305 | |||
306 | MODULE_LICENSE("GPL"); | ||
307 | MODULE_AUTHOR("Robert Schwebel <r.schwebel@pengutronix.de>, Sven Geggus <sven@geggus.net>"); | ||
308 | MODULE_DESCRIPTION("cpufreq driver for AMD's Elan CPUs"); | ||
309 | |||
310 | module_init(elanfreq_init); | ||
311 | module_exit(elanfreq_exit); | ||
312 | |||