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awilliam
GitHub Repository: awilliam/linux-vfio
Path: blob/master/arch/powerpc/platforms/powermac/cpufreq_64.c
10818 views
1
/*
2
* Copyright (C) 2002 - 2005 Benjamin Herrenschmidt <[email protected]>
3
* and Markus Demleitner <[email protected]>
4
*
5
* This program is free software; you can redistribute it and/or modify
6
* it under the terms of the GNU General Public License version 2 as
7
* published by the Free Software Foundation.
8
*
9
* This driver adds basic cpufreq support for SMU & 970FX based G5 Macs,
10
* that is iMac G5 and latest single CPU desktop.
11
*/
12
13
#undef DEBUG
14
15
#include <linux/module.h>
16
#include <linux/types.h>
17
#include <linux/errno.h>
18
#include <linux/kernel.h>
19
#include <linux/delay.h>
20
#include <linux/sched.h>
21
#include <linux/cpufreq.h>
22
#include <linux/init.h>
23
#include <linux/completion.h>
24
#include <linux/mutex.h>
25
#include <asm/prom.h>
26
#include <asm/machdep.h>
27
#include <asm/irq.h>
28
#include <asm/sections.h>
29
#include <asm/cputable.h>
30
#include <asm/time.h>
31
#include <asm/smu.h>
32
#include <asm/pmac_pfunc.h>
33
34
#define DBG(fmt...) pr_debug(fmt)
35
36
/* see 970FX user manual */
37
38
#define SCOM_PCR 0x0aa001 /* PCR scom addr */
39
40
#define PCR_HILO_SELECT 0x80000000U /* 1 = PCR, 0 = PCRH */
41
#define PCR_SPEED_FULL 0x00000000U /* 1:1 speed value */
42
#define PCR_SPEED_HALF 0x00020000U /* 1:2 speed value */
43
#define PCR_SPEED_QUARTER 0x00040000U /* 1:4 speed value */
44
#define PCR_SPEED_MASK 0x000e0000U /* speed mask */
45
#define PCR_SPEED_SHIFT 17
46
#define PCR_FREQ_REQ_VALID 0x00010000U /* freq request valid */
47
#define PCR_VOLT_REQ_VALID 0x00008000U /* volt request valid */
48
#define PCR_TARGET_TIME_MASK 0x00006000U /* target time */
49
#define PCR_STATLAT_MASK 0x00001f00U /* STATLAT value */
50
#define PCR_SNOOPLAT_MASK 0x000000f0U /* SNOOPLAT value */
51
#define PCR_SNOOPACC_MASK 0x0000000fU /* SNOOPACC value */
52
53
#define SCOM_PSR 0x408001 /* PSR scom addr */
54
/* warning: PSR is a 64 bits register */
55
#define PSR_CMD_RECEIVED 0x2000000000000000U /* command received */
56
#define PSR_CMD_COMPLETED 0x1000000000000000U /* command completed */
57
#define PSR_CUR_SPEED_MASK 0x0300000000000000U /* current speed */
58
#define PSR_CUR_SPEED_SHIFT (56)
59
60
/*
61
* The G5 only supports two frequencies (Quarter speed is not supported)
62
*/
63
#define CPUFREQ_HIGH 0
64
#define CPUFREQ_LOW 1
65
66
static struct cpufreq_frequency_table g5_cpu_freqs[] = {
67
{CPUFREQ_HIGH, 0},
68
{CPUFREQ_LOW, 0},
69
{0, CPUFREQ_TABLE_END},
70
};
71
72
static struct freq_attr* g5_cpu_freqs_attr[] = {
73
&cpufreq_freq_attr_scaling_available_freqs,
74
NULL,
75
};
76
77
/* Power mode data is an array of the 32 bits PCR values to use for
78
* the various frequencies, retrieved from the device-tree
79
*/
80
static int g5_pmode_cur;
81
82
static void (*g5_switch_volt)(int speed_mode);
83
static int (*g5_switch_freq)(int speed_mode);
84
static int (*g5_query_freq)(void);
85
86
static DEFINE_MUTEX(g5_switch_mutex);
87
88
static unsigned long transition_latency;
89
90
#ifdef CONFIG_PMAC_SMU
91
92
static const u32 *g5_pmode_data;
93
static int g5_pmode_max;
94
95
static struct smu_sdbp_fvt *g5_fvt_table; /* table of op. points */
96
static int g5_fvt_count; /* number of op. points */
97
static int g5_fvt_cur; /* current op. point */
98
99
/*
100
* SMU based voltage switching for Neo2 platforms
101
*/
102
103
static void g5_smu_switch_volt(int speed_mode)
104
{
105
struct smu_simple_cmd cmd;
106
107
DECLARE_COMPLETION_ONSTACK(comp);
108
smu_queue_simple(&cmd, SMU_CMD_POWER_COMMAND, 8, smu_done_complete,
109
&comp, 'V', 'S', 'L', 'E', 'W',
110
0xff, g5_fvt_cur+1, speed_mode);
111
wait_for_completion(&comp);
112
}
113
114
/*
115
* Platform function based voltage/vdnap switching for Neo2
116
*/
117
118
static struct pmf_function *pfunc_set_vdnap0;
119
static struct pmf_function *pfunc_vdnap0_complete;
120
121
static void g5_vdnap_switch_volt(int speed_mode)
122
{
123
struct pmf_args args;
124
u32 slew, done = 0;
125
unsigned long timeout;
126
127
slew = (speed_mode == CPUFREQ_LOW) ? 1 : 0;
128
args.count = 1;
129
args.u[0].p = &slew;
130
131
pmf_call_one(pfunc_set_vdnap0, &args);
132
133
/* It's an irq GPIO so we should be able to just block here,
134
* I'll do that later after I've properly tested the IRQ code for
135
* platform functions
136
*/
137
timeout = jiffies + HZ/10;
138
while(!time_after(jiffies, timeout)) {
139
args.count = 1;
140
args.u[0].p = &done;
141
pmf_call_one(pfunc_vdnap0_complete, &args);
142
if (done)
143
break;
144
msleep(1);
145
}
146
if (done == 0)
147
printk(KERN_WARNING "cpufreq: Timeout in clock slewing !\n");
148
}
149
150
151
/*
152
* SCOM based frequency switching for 970FX rev3
153
*/
154
static int g5_scom_switch_freq(int speed_mode)
155
{
156
unsigned long flags;
157
int to;
158
159
/* If frequency is going up, first ramp up the voltage */
160
if (speed_mode < g5_pmode_cur)
161
g5_switch_volt(speed_mode);
162
163
local_irq_save(flags);
164
165
/* Clear PCR high */
166
scom970_write(SCOM_PCR, 0);
167
/* Clear PCR low */
168
scom970_write(SCOM_PCR, PCR_HILO_SELECT | 0);
169
/* Set PCR low */
170
scom970_write(SCOM_PCR, PCR_HILO_SELECT |
171
g5_pmode_data[speed_mode]);
172
173
/* Wait for completion */
174
for (to = 0; to < 10; to++) {
175
unsigned long psr = scom970_read(SCOM_PSR);
176
177
if ((psr & PSR_CMD_RECEIVED) == 0 &&
178
(((psr >> PSR_CUR_SPEED_SHIFT) ^
179
(g5_pmode_data[speed_mode] >> PCR_SPEED_SHIFT)) & 0x3)
180
== 0)
181
break;
182
if (psr & PSR_CMD_COMPLETED)
183
break;
184
udelay(100);
185
}
186
187
local_irq_restore(flags);
188
189
/* If frequency is going down, last ramp the voltage */
190
if (speed_mode > g5_pmode_cur)
191
g5_switch_volt(speed_mode);
192
193
g5_pmode_cur = speed_mode;
194
ppc_proc_freq = g5_cpu_freqs[speed_mode].frequency * 1000ul;
195
196
return 0;
197
}
198
199
static int g5_scom_query_freq(void)
200
{
201
unsigned long psr = scom970_read(SCOM_PSR);
202
int i;
203
204
for (i = 0; i <= g5_pmode_max; i++)
205
if ((((psr >> PSR_CUR_SPEED_SHIFT) ^
206
(g5_pmode_data[i] >> PCR_SPEED_SHIFT)) & 0x3) == 0)
207
break;
208
return i;
209
}
210
211
/*
212
* Fake voltage switching for platforms with missing support
213
*/
214
215
static void g5_dummy_switch_volt(int speed_mode)
216
{
217
}
218
219
#endif /* CONFIG_PMAC_SMU */
220
221
/*
222
* Platform function based voltage switching for PowerMac7,2 & 7,3
223
*/
224
225
static struct pmf_function *pfunc_cpu0_volt_high;
226
static struct pmf_function *pfunc_cpu0_volt_low;
227
static struct pmf_function *pfunc_cpu1_volt_high;
228
static struct pmf_function *pfunc_cpu1_volt_low;
229
230
static void g5_pfunc_switch_volt(int speed_mode)
231
{
232
if (speed_mode == CPUFREQ_HIGH) {
233
if (pfunc_cpu0_volt_high)
234
pmf_call_one(pfunc_cpu0_volt_high, NULL);
235
if (pfunc_cpu1_volt_high)
236
pmf_call_one(pfunc_cpu1_volt_high, NULL);
237
} else {
238
if (pfunc_cpu0_volt_low)
239
pmf_call_one(pfunc_cpu0_volt_low, NULL);
240
if (pfunc_cpu1_volt_low)
241
pmf_call_one(pfunc_cpu1_volt_low, NULL);
242
}
243
msleep(10); /* should be faster , to fix */
244
}
245
246
/*
247
* Platform function based frequency switching for PowerMac7,2 & 7,3
248
*/
249
250
static struct pmf_function *pfunc_cpu_setfreq_high;
251
static struct pmf_function *pfunc_cpu_setfreq_low;
252
static struct pmf_function *pfunc_cpu_getfreq;
253
static struct pmf_function *pfunc_slewing_done;
254
255
static int g5_pfunc_switch_freq(int speed_mode)
256
{
257
struct pmf_args args;
258
u32 done = 0;
259
unsigned long timeout;
260
int rc;
261
262
DBG("g5_pfunc_switch_freq(%d)\n", speed_mode);
263
264
/* If frequency is going up, first ramp up the voltage */
265
if (speed_mode < g5_pmode_cur)
266
g5_switch_volt(speed_mode);
267
268
/* Do it */
269
if (speed_mode == CPUFREQ_HIGH)
270
rc = pmf_call_one(pfunc_cpu_setfreq_high, NULL);
271
else
272
rc = pmf_call_one(pfunc_cpu_setfreq_low, NULL);
273
274
if (rc)
275
printk(KERN_WARNING "cpufreq: pfunc switch error %d\n", rc);
276
277
/* It's an irq GPIO so we should be able to just block here,
278
* I'll do that later after I've properly tested the IRQ code for
279
* platform functions
280
*/
281
timeout = jiffies + HZ/10;
282
while(!time_after(jiffies, timeout)) {
283
args.count = 1;
284
args.u[0].p = &done;
285
pmf_call_one(pfunc_slewing_done, &args);
286
if (done)
287
break;
288
msleep(1);
289
}
290
if (done == 0)
291
printk(KERN_WARNING "cpufreq: Timeout in clock slewing !\n");
292
293
/* If frequency is going down, last ramp the voltage */
294
if (speed_mode > g5_pmode_cur)
295
g5_switch_volt(speed_mode);
296
297
g5_pmode_cur = speed_mode;
298
ppc_proc_freq = g5_cpu_freqs[speed_mode].frequency * 1000ul;
299
300
return 0;
301
}
302
303
static int g5_pfunc_query_freq(void)
304
{
305
struct pmf_args args;
306
u32 val = 0;
307
308
args.count = 1;
309
args.u[0].p = &val;
310
pmf_call_one(pfunc_cpu_getfreq, &args);
311
return val ? CPUFREQ_HIGH : CPUFREQ_LOW;
312
}
313
314
315
/*
316
* Common interface to the cpufreq core
317
*/
318
319
static int g5_cpufreq_verify(struct cpufreq_policy *policy)
320
{
321
return cpufreq_frequency_table_verify(policy, g5_cpu_freqs);
322
}
323
324
static int g5_cpufreq_target(struct cpufreq_policy *policy,
325
unsigned int target_freq, unsigned int relation)
326
{
327
unsigned int newstate = 0;
328
struct cpufreq_freqs freqs;
329
int rc;
330
331
if (cpufreq_frequency_table_target(policy, g5_cpu_freqs,
332
target_freq, relation, &newstate))
333
return -EINVAL;
334
335
if (g5_pmode_cur == newstate)
336
return 0;
337
338
mutex_lock(&g5_switch_mutex);
339
340
freqs.old = g5_cpu_freqs[g5_pmode_cur].frequency;
341
freqs.new = g5_cpu_freqs[newstate].frequency;
342
freqs.cpu = 0;
343
344
cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
345
rc = g5_switch_freq(newstate);
346
cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
347
348
mutex_unlock(&g5_switch_mutex);
349
350
return rc;
351
}
352
353
static unsigned int g5_cpufreq_get_speed(unsigned int cpu)
354
{
355
return g5_cpu_freqs[g5_pmode_cur].frequency;
356
}
357
358
static int g5_cpufreq_cpu_init(struct cpufreq_policy *policy)
359
{
360
policy->cpuinfo.transition_latency = transition_latency;
361
policy->cur = g5_cpu_freqs[g5_query_freq()].frequency;
362
/* secondary CPUs are tied to the primary one by the
363
* cpufreq core if in the secondary policy we tell it that
364
* it actually must be one policy together with all others. */
365
cpumask_copy(policy->cpus, cpu_online_mask);
366
cpufreq_frequency_table_get_attr(g5_cpu_freqs, policy->cpu);
367
368
return cpufreq_frequency_table_cpuinfo(policy,
369
g5_cpu_freqs);
370
}
371
372
373
static struct cpufreq_driver g5_cpufreq_driver = {
374
.name = "powermac",
375
.owner = THIS_MODULE,
376
.flags = CPUFREQ_CONST_LOOPS,
377
.init = g5_cpufreq_cpu_init,
378
.verify = g5_cpufreq_verify,
379
.target = g5_cpufreq_target,
380
.get = g5_cpufreq_get_speed,
381
.attr = g5_cpu_freqs_attr,
382
};
383
384
385
#ifdef CONFIG_PMAC_SMU
386
387
static int __init g5_neo2_cpufreq_init(struct device_node *cpus)
388
{
389
struct device_node *cpunode;
390
unsigned int psize, ssize;
391
unsigned long max_freq;
392
char *freq_method, *volt_method;
393
const u32 *valp;
394
u32 pvr_hi;
395
int use_volts_vdnap = 0;
396
int use_volts_smu = 0;
397
int rc = -ENODEV;
398
399
/* Check supported platforms */
400
if (of_machine_is_compatible("PowerMac8,1") ||
401
of_machine_is_compatible("PowerMac8,2") ||
402
of_machine_is_compatible("PowerMac9,1"))
403
use_volts_smu = 1;
404
else if (of_machine_is_compatible("PowerMac11,2"))
405
use_volts_vdnap = 1;
406
else
407
return -ENODEV;
408
409
/* Get first CPU node */
410
for (cpunode = NULL;
411
(cpunode = of_get_next_child(cpus, cpunode)) != NULL;) {
412
const u32 *reg = of_get_property(cpunode, "reg", NULL);
413
if (reg == NULL || (*reg) != 0)
414
continue;
415
if (!strcmp(cpunode->type, "cpu"))
416
break;
417
}
418
if (cpunode == NULL) {
419
printk(KERN_ERR "cpufreq: Can't find any CPU 0 node\n");
420
return -ENODEV;
421
}
422
423
/* Check 970FX for now */
424
valp = of_get_property(cpunode, "cpu-version", NULL);
425
if (!valp) {
426
DBG("No cpu-version property !\n");
427
goto bail_noprops;
428
}
429
pvr_hi = (*valp) >> 16;
430
if (pvr_hi != 0x3c && pvr_hi != 0x44) {
431
printk(KERN_ERR "cpufreq: Unsupported CPU version\n");
432
goto bail_noprops;
433
}
434
435
/* Look for the powertune data in the device-tree */
436
g5_pmode_data = of_get_property(cpunode, "power-mode-data",&psize);
437
if (!g5_pmode_data) {
438
DBG("No power-mode-data !\n");
439
goto bail_noprops;
440
}
441
g5_pmode_max = psize / sizeof(u32) - 1;
442
443
if (use_volts_smu) {
444
const struct smu_sdbp_header *shdr;
445
446
/* Look for the FVT table */
447
shdr = smu_get_sdb_partition(SMU_SDB_FVT_ID, NULL);
448
if (!shdr)
449
goto bail_noprops;
450
g5_fvt_table = (struct smu_sdbp_fvt *)&shdr[1];
451
ssize = (shdr->len * sizeof(u32)) -
452
sizeof(struct smu_sdbp_header);
453
g5_fvt_count = ssize / sizeof(struct smu_sdbp_fvt);
454
g5_fvt_cur = 0;
455
456
/* Sanity checking */
457
if (g5_fvt_count < 1 || g5_pmode_max < 1)
458
goto bail_noprops;
459
460
g5_switch_volt = g5_smu_switch_volt;
461
volt_method = "SMU";
462
} else if (use_volts_vdnap) {
463
struct device_node *root;
464
465
root = of_find_node_by_path("/");
466
if (root == NULL) {
467
printk(KERN_ERR "cpufreq: Can't find root of "
468
"device tree\n");
469
goto bail_noprops;
470
}
471
pfunc_set_vdnap0 = pmf_find_function(root, "set-vdnap0");
472
pfunc_vdnap0_complete =
473
pmf_find_function(root, "slewing-done");
474
if (pfunc_set_vdnap0 == NULL ||
475
pfunc_vdnap0_complete == NULL) {
476
printk(KERN_ERR "cpufreq: Can't find required "
477
"platform function\n");
478
goto bail_noprops;
479
}
480
481
g5_switch_volt = g5_vdnap_switch_volt;
482
volt_method = "GPIO";
483
} else {
484
g5_switch_volt = g5_dummy_switch_volt;
485
volt_method = "none";
486
}
487
488
/*
489
* From what I see, clock-frequency is always the maximal frequency.
490
* The current driver can not slew sysclk yet, so we really only deal
491
* with powertune steps for now. We also only implement full freq and
492
* half freq in this version. So far, I haven't yet seen a machine
493
* supporting anything else.
494
*/
495
valp = of_get_property(cpunode, "clock-frequency", NULL);
496
if (!valp)
497
return -ENODEV;
498
max_freq = (*valp)/1000;
499
g5_cpu_freqs[0].frequency = max_freq;
500
g5_cpu_freqs[1].frequency = max_freq/2;
501
502
/* Set callbacks */
503
transition_latency = 12000;
504
g5_switch_freq = g5_scom_switch_freq;
505
g5_query_freq = g5_scom_query_freq;
506
freq_method = "SCOM";
507
508
/* Force apply current frequency to make sure everything is in
509
* sync (voltage is right for example). Firmware may leave us with
510
* a strange setting ...
511
*/
512
g5_switch_volt(CPUFREQ_HIGH);
513
msleep(10);
514
g5_pmode_cur = -1;
515
g5_switch_freq(g5_query_freq());
516
517
printk(KERN_INFO "Registering G5 CPU frequency driver\n");
518
printk(KERN_INFO "Frequency method: %s, Voltage method: %s\n",
519
freq_method, volt_method);
520
printk(KERN_INFO "Low: %d Mhz, High: %d Mhz, Cur: %d MHz\n",
521
g5_cpu_freqs[1].frequency/1000,
522
g5_cpu_freqs[0].frequency/1000,
523
g5_cpu_freqs[g5_pmode_cur].frequency/1000);
524
525
rc = cpufreq_register_driver(&g5_cpufreq_driver);
526
527
/* We keep the CPU node on hold... hopefully, Apple G5 don't have
528
* hotplug CPU with a dynamic device-tree ...
529
*/
530
return rc;
531
532
bail_noprops:
533
of_node_put(cpunode);
534
535
return rc;
536
}
537
538
#endif /* CONFIG_PMAC_SMU */
539
540
541
static int __init g5_pm72_cpufreq_init(struct device_node *cpus)
542
{
543
struct device_node *cpuid = NULL, *hwclock = NULL, *cpunode = NULL;
544
const u8 *eeprom = NULL;
545
const u32 *valp;
546
u64 max_freq, min_freq, ih, il;
547
int has_volt = 1, rc = 0;
548
549
DBG("cpufreq: Initializing for PowerMac7,2, PowerMac7,3 and"
550
" RackMac3,1...\n");
551
552
/* Get first CPU node */
553
for (cpunode = NULL;
554
(cpunode = of_get_next_child(cpus, cpunode)) != NULL;) {
555
if (!strcmp(cpunode->type, "cpu"))
556
break;
557
}
558
if (cpunode == NULL) {
559
printk(KERN_ERR "cpufreq: Can't find any CPU node\n");
560
return -ENODEV;
561
}
562
563
/* Lookup the cpuid eeprom node */
564
cpuid = of_find_node_by_path("/u3@0,f8000000/i2c@f8001000/cpuid@a0");
565
if (cpuid != NULL)
566
eeprom = of_get_property(cpuid, "cpuid", NULL);
567
if (eeprom == NULL) {
568
printk(KERN_ERR "cpufreq: Can't find cpuid EEPROM !\n");
569
rc = -ENODEV;
570
goto bail;
571
}
572
573
/* Lookup the i2c hwclock */
574
for (hwclock = NULL;
575
(hwclock = of_find_node_by_name(hwclock, "i2c-hwclock")) != NULL;){
576
const char *loc = of_get_property(hwclock,
577
"hwctrl-location", NULL);
578
if (loc == NULL)
579
continue;
580
if (strcmp(loc, "CPU CLOCK"))
581
continue;
582
if (!of_get_property(hwclock, "platform-get-frequency", NULL))
583
continue;
584
break;
585
}
586
if (hwclock == NULL) {
587
printk(KERN_ERR "cpufreq: Can't find i2c clock chip !\n");
588
rc = -ENODEV;
589
goto bail;
590
}
591
592
DBG("cpufreq: i2c clock chip found: %s\n", hwclock->full_name);
593
594
/* Now get all the platform functions */
595
pfunc_cpu_getfreq =
596
pmf_find_function(hwclock, "get-frequency");
597
pfunc_cpu_setfreq_high =
598
pmf_find_function(hwclock, "set-frequency-high");
599
pfunc_cpu_setfreq_low =
600
pmf_find_function(hwclock, "set-frequency-low");
601
pfunc_slewing_done =
602
pmf_find_function(hwclock, "slewing-done");
603
pfunc_cpu0_volt_high =
604
pmf_find_function(hwclock, "set-voltage-high-0");
605
pfunc_cpu0_volt_low =
606
pmf_find_function(hwclock, "set-voltage-low-0");
607
pfunc_cpu1_volt_high =
608
pmf_find_function(hwclock, "set-voltage-high-1");
609
pfunc_cpu1_volt_low =
610
pmf_find_function(hwclock, "set-voltage-low-1");
611
612
/* Check we have minimum requirements */
613
if (pfunc_cpu_getfreq == NULL || pfunc_cpu_setfreq_high == NULL ||
614
pfunc_cpu_setfreq_low == NULL || pfunc_slewing_done == NULL) {
615
printk(KERN_ERR "cpufreq: Can't find platform functions !\n");
616
rc = -ENODEV;
617
goto bail;
618
}
619
620
/* Check that we have complete sets */
621
if (pfunc_cpu0_volt_high == NULL || pfunc_cpu0_volt_low == NULL) {
622
pmf_put_function(pfunc_cpu0_volt_high);
623
pmf_put_function(pfunc_cpu0_volt_low);
624
pfunc_cpu0_volt_high = pfunc_cpu0_volt_low = NULL;
625
has_volt = 0;
626
}
627
if (!has_volt ||
628
pfunc_cpu1_volt_high == NULL || pfunc_cpu1_volt_low == NULL) {
629
pmf_put_function(pfunc_cpu1_volt_high);
630
pmf_put_function(pfunc_cpu1_volt_low);
631
pfunc_cpu1_volt_high = pfunc_cpu1_volt_low = NULL;
632
}
633
634
/* Note: The device tree also contains a "platform-set-values"
635
* function for which I haven't quite figured out the usage. It
636
* might have to be called on init and/or wakeup, I'm not too sure
637
* but things seem to work fine without it so far ...
638
*/
639
640
/* Get max frequency from device-tree */
641
valp = of_get_property(cpunode, "clock-frequency", NULL);
642
if (!valp) {
643
printk(KERN_ERR "cpufreq: Can't find CPU frequency !\n");
644
rc = -ENODEV;
645
goto bail;
646
}
647
648
max_freq = (*valp)/1000;
649
650
/* Now calculate reduced frequency by using the cpuid input freq
651
* ratio. This requires 64 bits math unless we are willing to lose
652
* some precision
653
*/
654
ih = *((u32 *)(eeprom + 0x10));
655
il = *((u32 *)(eeprom + 0x20));
656
657
/* Check for machines with no useful settings */
658
if (il == ih) {
659
printk(KERN_WARNING "cpufreq: No low frequency mode available"
660
" on this model !\n");
661
rc = -ENODEV;
662
goto bail;
663
}
664
665
min_freq = 0;
666
if (ih != 0 && il != 0)
667
min_freq = (max_freq * il) / ih;
668
669
/* Sanity check */
670
if (min_freq >= max_freq || min_freq < 1000) {
671
printk(KERN_ERR "cpufreq: Can't calculate low frequency !\n");
672
rc = -ENXIO;
673
goto bail;
674
}
675
g5_cpu_freqs[0].frequency = max_freq;
676
g5_cpu_freqs[1].frequency = min_freq;
677
678
/* Set callbacks */
679
transition_latency = CPUFREQ_ETERNAL;
680
g5_switch_volt = g5_pfunc_switch_volt;
681
g5_switch_freq = g5_pfunc_switch_freq;
682
g5_query_freq = g5_pfunc_query_freq;
683
684
/* Force apply current frequency to make sure everything is in
685
* sync (voltage is right for example). Firmware may leave us with
686
* a strange setting ...
687
*/
688
g5_switch_volt(CPUFREQ_HIGH);
689
msleep(10);
690
g5_pmode_cur = -1;
691
g5_switch_freq(g5_query_freq());
692
693
printk(KERN_INFO "Registering G5 CPU frequency driver\n");
694
printk(KERN_INFO "Frequency method: i2c/pfunc, "
695
"Voltage method: %s\n", has_volt ? "i2c/pfunc" : "none");
696
printk(KERN_INFO "Low: %d Mhz, High: %d Mhz, Cur: %d MHz\n",
697
g5_cpu_freqs[1].frequency/1000,
698
g5_cpu_freqs[0].frequency/1000,
699
g5_cpu_freqs[g5_pmode_cur].frequency/1000);
700
701
rc = cpufreq_register_driver(&g5_cpufreq_driver);
702
bail:
703
if (rc != 0) {
704
pmf_put_function(pfunc_cpu_getfreq);
705
pmf_put_function(pfunc_cpu_setfreq_high);
706
pmf_put_function(pfunc_cpu_setfreq_low);
707
pmf_put_function(pfunc_slewing_done);
708
pmf_put_function(pfunc_cpu0_volt_high);
709
pmf_put_function(pfunc_cpu0_volt_low);
710
pmf_put_function(pfunc_cpu1_volt_high);
711
pmf_put_function(pfunc_cpu1_volt_low);
712
}
713
of_node_put(hwclock);
714
of_node_put(cpuid);
715
of_node_put(cpunode);
716
717
return rc;
718
}
719
720
static int __init g5_cpufreq_init(void)
721
{
722
struct device_node *cpus;
723
int rc = 0;
724
725
cpus = of_find_node_by_path("/cpus");
726
if (cpus == NULL) {
727
DBG("No /cpus node !\n");
728
return -ENODEV;
729
}
730
731
if (of_machine_is_compatible("PowerMac7,2") ||
732
of_machine_is_compatible("PowerMac7,3") ||
733
of_machine_is_compatible("RackMac3,1"))
734
rc = g5_pm72_cpufreq_init(cpus);
735
#ifdef CONFIG_PMAC_SMU
736
else
737
rc = g5_neo2_cpufreq_init(cpus);
738
#endif /* CONFIG_PMAC_SMU */
739
740
of_node_put(cpus);
741
return rc;
742
}
743
744
module_init(g5_cpufreq_init);
745
746
747
MODULE_LICENSE("GPL");
748
749