This source file includes following definitions.
- nforce2_calc_fsb
- nforce2_calc_pll
- nforce2_write_pll
- nforce2_fsb_read
- nforce2_set_fsb
- nforce2_get
- nforce2_target
- nforce2_verify
- nforce2_cpu_init
- nforce2_cpu_exit
- nforce2_detect_chipset
- nforce2_init
- nforce2_exit
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9
10 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
11
12 #include <linux/kernel.h>
13 #include <linux/module.h>
14 #include <linux/moduleparam.h>
15 #include <linux/init.h>
16 #include <linux/cpufreq.h>
17 #include <linux/pci.h>
18 #include <linux/delay.h>
19
20 #define NFORCE2_XTAL 25
21 #define NFORCE2_BOOTFSB 0x48
22 #define NFORCE2_PLLENABLE 0xa8
23 #define NFORCE2_PLLREG 0xa4
24 #define NFORCE2_PLLADR 0xa0
25 #define NFORCE2_PLL(mul, div) (0x100000 | (mul << 8) | div)
26
27 #define NFORCE2_MIN_FSB 50
28 #define NFORCE2_SAFE_DISTANCE 50
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35
36
37 static struct pci_dev *nforce2_dev;
38
39
40
41
42 static int fid;
43
44
45
46
47 static int min_fsb;
48 static int max_fsb;
49
50 MODULE_AUTHOR("Sebastian Witt <se.witt@gmx.net>");
51 MODULE_DESCRIPTION("nForce2 FSB changing cpufreq driver");
52 MODULE_LICENSE("GPL");
53
54 module_param(fid, int, 0444);
55 module_param(min_fsb, int, 0444);
56
57 MODULE_PARM_DESC(fid, "CPU multiplier to use (11.5 = 115)");
58 MODULE_PARM_DESC(min_fsb,
59 "Minimum FSB to use, if not defined: current FSB - 50");
60
61
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65
66
67 static int nforce2_calc_fsb(int pll)
68 {
69 unsigned char mul, div;
70
71 mul = (pll >> 8) & 0xff;
72 div = pll & 0xff;
73
74 if (div > 0)
75 return NFORCE2_XTAL * mul / div;
76
77 return 0;
78 }
79
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83
84
85
86 static int nforce2_calc_pll(unsigned int fsb)
87 {
88 unsigned char xmul, xdiv;
89 unsigned char mul = 0, div = 0;
90 int tried = 0;
91
92
93 while (((mul == 0) || (div == 0)) && (tried <= 3)) {
94 for (xdiv = 2; xdiv <= 0x80; xdiv++)
95 for (xmul = 1; xmul <= 0xfe; xmul++)
96 if (nforce2_calc_fsb(NFORCE2_PLL(xmul, xdiv)) ==
97 fsb + tried) {
98 mul = xmul;
99 div = xdiv;
100 }
101 tried++;
102 }
103
104 if ((mul == 0) || (div == 0))
105 return -1;
106
107 return NFORCE2_PLL(mul, div);
108 }
109
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114
115
116 static void nforce2_write_pll(int pll)
117 {
118 int temp;
119
120
121 pci_write_config_dword(nforce2_dev, NFORCE2_PLLADR, 0);
122
123
124 for (temp = 0; temp <= 0x3f; temp++)
125 pci_write_config_dword(nforce2_dev, NFORCE2_PLLREG, pll);
126 }
127
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132
133
134 static unsigned int nforce2_fsb_read(int bootfsb)
135 {
136 struct pci_dev *nforce2_sub5;
137 u32 fsb, temp = 0;
138
139
140 nforce2_sub5 = pci_get_subsys(PCI_VENDOR_ID_NVIDIA, 0x01EF,
141 PCI_ANY_ID, PCI_ANY_ID, NULL);
142 if (!nforce2_sub5)
143 return 0;
144
145 pci_read_config_dword(nforce2_sub5, NFORCE2_BOOTFSB, &fsb);
146 fsb /= 1000000;
147
148
149 pci_read_config_byte(nforce2_dev, NFORCE2_PLLENABLE, (u8 *)&temp);
150
151 if (bootfsb || !temp)
152 return fsb;
153
154
155 pci_read_config_dword(nforce2_dev, NFORCE2_PLLREG, &temp);
156 fsb = nforce2_calc_fsb(temp);
157
158 return fsb;
159 }
160
161
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165
166
167 static int nforce2_set_fsb(unsigned int fsb)
168 {
169 u32 temp = 0;
170 unsigned int tfsb;
171 int diff;
172 int pll = 0;
173
174 if ((fsb > max_fsb) || (fsb < NFORCE2_MIN_FSB)) {
175 pr_err("FSB %d is out of range!\n", fsb);
176 return -EINVAL;
177 }
178
179 tfsb = nforce2_fsb_read(0);
180 if (!tfsb) {
181 pr_err("Error while reading the FSB\n");
182 return -EINVAL;
183 }
184
185
186 pci_read_config_byte(nforce2_dev, NFORCE2_PLLENABLE, (u8 *)&temp);
187 if (!temp) {
188 pll = nforce2_calc_pll(tfsb);
189
190 if (pll < 0)
191 return -EINVAL;
192
193 nforce2_write_pll(pll);
194 }
195
196
197 temp = 0x01;
198 pci_write_config_byte(nforce2_dev, NFORCE2_PLLENABLE, (u8)temp);
199
200 diff = tfsb - fsb;
201
202 if (!diff)
203 return 0;
204
205 while ((tfsb != fsb) && (tfsb <= max_fsb) && (tfsb >= min_fsb)) {
206 if (diff < 0)
207 tfsb++;
208 else
209 tfsb--;
210
211
212 pll = nforce2_calc_pll(tfsb);
213 if (pll == -1)
214 return -EINVAL;
215
216 nforce2_write_pll(pll);
217 #ifdef NFORCE2_DELAY
218 mdelay(NFORCE2_DELAY);
219 #endif
220 }
221
222 temp = 0x40;
223 pci_write_config_byte(nforce2_dev, NFORCE2_PLLADR, (u8)temp);
224
225 return 0;
226 }
227
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231
232
233
234 static unsigned int nforce2_get(unsigned int cpu)
235 {
236 if (cpu)
237 return 0;
238 return nforce2_fsb_read(0) * fid * 100;
239 }
240
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248
249
250 static int nforce2_target(struct cpufreq_policy *policy,
251 unsigned int target_freq, unsigned int relation)
252 {
253
254 struct cpufreq_freqs freqs;
255 unsigned int target_fsb;
256
257 if ((target_freq > policy->max) || (target_freq < policy->min))
258 return -EINVAL;
259
260 target_fsb = target_freq / (fid * 100);
261
262 freqs.old = nforce2_get(policy->cpu);
263 freqs.new = target_fsb * fid * 100;
264
265 if (freqs.old == freqs.new)
266 return 0;
267
268 pr_debug("Old CPU frequency %d kHz, new %d kHz\n",
269 freqs.old, freqs.new);
270
271 cpufreq_freq_transition_begin(policy, &freqs);
272
273
274
275
276 if (nforce2_set_fsb(target_fsb) < 0)
277 pr_err("Changing FSB to %d failed\n", target_fsb);
278 else
279 pr_debug("Changed FSB successfully to %d\n",
280 target_fsb);
281
282
283
284
285 cpufreq_freq_transition_end(policy, &freqs, 0);
286
287 return 0;
288 }
289
290
291
292
293
294 static int nforce2_verify(struct cpufreq_policy_data *policy)
295 {
296 unsigned int fsb_pol_max;
297
298 fsb_pol_max = policy->max / (fid * 100);
299
300 if (policy->min < (fsb_pol_max * fid * 100))
301 policy->max = (fsb_pol_max + 1) * fid * 100;
302
303 cpufreq_verify_within_cpu_limits(policy);
304 return 0;
305 }
306
307 static int nforce2_cpu_init(struct cpufreq_policy *policy)
308 {
309 unsigned int fsb;
310 unsigned int rfid;
311
312
313 if (policy->cpu != 0)
314 return -ENODEV;
315
316
317 fsb = nforce2_fsb_read(0);
318
319 if (!fsb)
320 return -EIO;
321
322
323 if (!fid) {
324 if (!cpu_khz) {
325 pr_warn("cpu_khz not set, can't calculate multiplier!\n");
326 return -ENODEV;
327 }
328
329 fid = cpu_khz / (fsb * 100);
330 rfid = fid % 5;
331
332 if (rfid) {
333 if (rfid > 2)
334 fid += 5 - rfid;
335 else
336 fid -= rfid;
337 }
338 }
339
340 pr_info("FSB currently at %i MHz, FID %d.%d\n",
341 fsb, fid / 10, fid % 10);
342
343
344 max_fsb = nforce2_fsb_read(1);
345
346 if (!max_fsb)
347 return -EIO;
348
349 if (!min_fsb)
350 min_fsb = max_fsb - NFORCE2_SAFE_DISTANCE;
351
352 if (min_fsb < NFORCE2_MIN_FSB)
353 min_fsb = NFORCE2_MIN_FSB;
354
355
356 policy->min = policy->cpuinfo.min_freq = min_fsb * fid * 100;
357 policy->max = policy->cpuinfo.max_freq = max_fsb * fid * 100;
358
359 return 0;
360 }
361
362 static int nforce2_cpu_exit(struct cpufreq_policy *policy)
363 {
364 return 0;
365 }
366
367 static struct cpufreq_driver nforce2_driver = {
368 .name = "nforce2",
369 .flags = CPUFREQ_NO_AUTO_DYNAMIC_SWITCHING,
370 .verify = nforce2_verify,
371 .target = nforce2_target,
372 .get = nforce2_get,
373 .init = nforce2_cpu_init,
374 .exit = nforce2_cpu_exit,
375 };
376
377 #ifdef MODULE
378 static const struct pci_device_id nforce2_ids[] = {
379 { PCI_VENDOR_ID_NVIDIA, PCI_DEVICE_ID_NVIDIA_NFORCE2 },
380 {}
381 };
382 MODULE_DEVICE_TABLE(pci, nforce2_ids);
383 #endif
384
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388
389
390
391 static int nforce2_detect_chipset(void)
392 {
393 nforce2_dev = pci_get_subsys(PCI_VENDOR_ID_NVIDIA,
394 PCI_DEVICE_ID_NVIDIA_NFORCE2,
395 PCI_ANY_ID, PCI_ANY_ID, NULL);
396
397 if (nforce2_dev == NULL)
398 return -ENODEV;
399
400 pr_info("Detected nForce2 chipset revision %X\n",
401 nforce2_dev->revision);
402 pr_info("FSB changing is maybe unstable and can lead to crashes and data loss\n");
403
404 return 0;
405 }
406
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411
412
413
414 static int __init nforce2_init(void)
415 {
416
417
418
419 if (nforce2_detect_chipset()) {
420 pr_info("No nForce2 chipset\n");
421 return -ENODEV;
422 }
423
424 return cpufreq_register_driver(&nforce2_driver);
425 }
426
427
428
429
430
431
432 static void __exit nforce2_exit(void)
433 {
434 cpufreq_unregister_driver(&nforce2_driver);
435 }
436
437 module_init(nforce2_init);
438 module_exit(nforce2_exit);