1 /*
2 * Copyright (C) 2002 - 2005 Benjamin Herrenschmidt <benh@kernel.crashing.org>
3 * and Markus Demleitner <msdemlei@cl.uni-heidelberg.de>
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
g5_smu_switch_volt(int speed_mode)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
g5_vdnap_switch_volt(int speed_mode)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 */
g5_scom_switch_freq(int speed_mode)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
g5_scom_query_freq(void)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
g5_dummy_switch_volt(int speed_mode)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
g5_pfunc_switch_volt(int speed_mode)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
g5_pfunc_switch_freq(int speed_mode)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
g5_pfunc_query_freq(void)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
g5_cpufreq_verify(struct cpufreq_policy * policy)319 static int g5_cpufreq_verify(struct cpufreq_policy *policy)
320 {
321 return cpufreq_frequency_table_verify(policy, g5_cpu_freqs);
322 }
323
g5_cpufreq_target(struct cpufreq_policy * policy,unsigned int target_freq,unsigned int relation)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
g5_cpufreq_get_speed(unsigned int cpu)353 static unsigned int g5_cpufreq_get_speed(unsigned int cpu)
354 {
355 return g5_cpu_freqs[g5_pmode_cur].frequency;
356 }
357
g5_cpufreq_cpu_init(struct cpufreq_policy * policy)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
g5_neo2_cpufreq_init(struct device_node * cpus)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
g5_pm72_cpufreq_init(struct device_node * cpus)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
g5_cpufreq_init(void)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