1 /*
2  *  Copyright (C) 2002 - 2005 Benjamin Herrenschmidt <benh@kernel.crashing.org>
3  *  Copyright (C) 2004        John Steele Scott <toojays@toojays.net>
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  * TODO: Need a big cleanup here. Basically, we need to have different
10  * cpufreq_driver structures for the different type of HW instead of the
11  * current mess. We also need to better deal with the detection of the
12  * type of machine.
13  *
14  */
15 
16 #include <linux/module.h>
17 #include <linux/types.h>
18 #include <linux/errno.h>
19 #include <linux/kernel.h>
20 #include <linux/delay.h>
21 #include <linux/sched.h>
22 #include <linux/adb.h>
23 #include <linux/pmu.h>
24 #include <linux/cpufreq.h>
25 #include <linux/init.h>
26 #include <linux/device.h>
27 #include <linux/hardirq.h>
28 #include <linux/of_device.h>
29 #include <asm/prom.h>
30 #include <asm/machdep.h>
31 #include <asm/irq.h>
32 #include <asm/pmac_feature.h>
33 #include <asm/mmu_context.h>
34 #include <asm/sections.h>
35 #include <asm/cputable.h>
36 #include <asm/time.h>
37 #include <asm/mpic.h>
38 #include <asm/keylargo.h>
39 #include <asm/switch_to.h>
40 
41 /* WARNING !!! This will cause calibrate_delay() to be called,
42  * but this is an __init function ! So you MUST go edit
43  * init/main.c to make it non-init before enabling DEBUG_FREQ
44  */
45 #undef DEBUG_FREQ
46 
47 extern void low_choose_7447a_dfs(int dfs);
48 extern void low_choose_750fx_pll(int pll);
49 extern void low_sleep_handler(void);
50 
51 /*
52  * Currently, PowerMac cpufreq supports only high & low frequencies
53  * that are set by the firmware
54  */
55 static unsigned int low_freq;
56 static unsigned int hi_freq;
57 static unsigned int cur_freq;
58 static unsigned int sleep_freq;
59 static unsigned long transition_latency;
60 
61 /*
62  * Different models uses different mechanisms to switch the frequency
63  */
64 static int (*set_speed_proc)(int low_speed);
65 static unsigned int (*get_speed_proc)(void);
66 
67 /*
68  * Some definitions used by the various speedprocs
69  */
70 static u32 voltage_gpio;
71 static u32 frequency_gpio;
72 static u32 slew_done_gpio;
73 static int no_schedule;
74 static int has_cpu_l2lve;
75 static int is_pmu_based;
76 
77 /* There are only two frequency states for each processor. Values
78  * are in kHz for the time being.
79  */
80 #define CPUFREQ_HIGH                  0
81 #define CPUFREQ_LOW                   1
82 
83 static struct cpufreq_frequency_table pmac_cpu_freqs[] = {
84 	{0, CPUFREQ_HIGH,	0},
85 	{0, CPUFREQ_LOW,	0},
86 	{0, 0,			CPUFREQ_TABLE_END},
87 };
88 
89 static inline void local_delay(unsigned long ms)
90 {
91 	if (no_schedule)
92 		mdelay(ms);
93 	else
94 		msleep(ms);
95 }
96 
97 #ifdef DEBUG_FREQ
98 static inline void debug_calc_bogomips(void)
99 {
100 	/* This will cause a recalc of bogomips and display the
101 	 * result. We backup/restore the value to avoid affecting the
102 	 * core cpufreq framework's own calculation.
103 	 */
104 	unsigned long save_lpj = loops_per_jiffy;
105 	calibrate_delay();
106 	loops_per_jiffy = save_lpj;
107 }
108 #endif /* DEBUG_FREQ */
109 
110 /* Switch CPU speed under 750FX CPU control
111  */
112 static int cpu_750fx_cpu_speed(int low_speed)
113 {
114 	u32 hid2;
115 
116 	if (low_speed == 0) {
117 		/* ramping up, set voltage first */
118 		pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, voltage_gpio, 0x05);
119 		/* Make sure we sleep for at least 1ms */
120 		local_delay(10);
121 
122 		/* tweak L2 for high voltage */
123 		if (has_cpu_l2lve) {
124 			hid2 = mfspr(SPRN_HID2);
125 			hid2 &= ~0x2000;
126 			mtspr(SPRN_HID2, hid2);
127 		}
128 	}
129 #ifdef CONFIG_6xx
130 	low_choose_750fx_pll(low_speed);
131 #endif
132 	if (low_speed == 1) {
133 		/* tweak L2 for low voltage */
134 		if (has_cpu_l2lve) {
135 			hid2 = mfspr(SPRN_HID2);
136 			hid2 |= 0x2000;
137 			mtspr(SPRN_HID2, hid2);
138 		}
139 
140 		/* ramping down, set voltage last */
141 		pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, voltage_gpio, 0x04);
142 		local_delay(10);
143 	}
144 
145 	return 0;
146 }
147 
148 static unsigned int cpu_750fx_get_cpu_speed(void)
149 {
150 	if (mfspr(SPRN_HID1) & HID1_PS)
151 		return low_freq;
152 	else
153 		return hi_freq;
154 }
155 
156 /* Switch CPU speed using DFS */
157 static int dfs_set_cpu_speed(int low_speed)
158 {
159 	if (low_speed == 0) {
160 		/* ramping up, set voltage first */
161 		pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, voltage_gpio, 0x05);
162 		/* Make sure we sleep for at least 1ms */
163 		local_delay(1);
164 	}
165 
166 	/* set frequency */
167 #ifdef CONFIG_6xx
168 	low_choose_7447a_dfs(low_speed);
169 #endif
170 	udelay(100);
171 
172 	if (low_speed == 1) {
173 		/* ramping down, set voltage last */
174 		pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, voltage_gpio, 0x04);
175 		local_delay(1);
176 	}
177 
178 	return 0;
179 }
180 
181 static unsigned int dfs_get_cpu_speed(void)
182 {
183 	if (mfspr(SPRN_HID1) & HID1_DFS)
184 		return low_freq;
185 	else
186 		return hi_freq;
187 }
188 
189 
190 /* Switch CPU speed using slewing GPIOs
191  */
192 static int gpios_set_cpu_speed(int low_speed)
193 {
194 	int gpio, timeout = 0;
195 
196 	/* If ramping up, set voltage first */
197 	if (low_speed == 0) {
198 		pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, voltage_gpio, 0x05);
199 		/* Delay is way too big but it's ok, we schedule */
200 		local_delay(10);
201 	}
202 
203 	/* Set frequency */
204 	gpio = 	pmac_call_feature(PMAC_FTR_READ_GPIO, NULL, frequency_gpio, 0);
205 	if (low_speed == ((gpio & 0x01) == 0))
206 		goto skip;
207 
208 	pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, frequency_gpio,
209 			  low_speed ? 0x04 : 0x05);
210 	udelay(200);
211 	do {
212 		if (++timeout > 100)
213 			break;
214 		local_delay(1);
215 		gpio = pmac_call_feature(PMAC_FTR_READ_GPIO, NULL, slew_done_gpio, 0);
216 	} while((gpio & 0x02) == 0);
217  skip:
218 	/* If ramping down, set voltage last */
219 	if (low_speed == 1) {
220 		pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, voltage_gpio, 0x04);
221 		/* Delay is way too big but it's ok, we schedule */
222 		local_delay(10);
223 	}
224 
225 #ifdef DEBUG_FREQ
226 	debug_calc_bogomips();
227 #endif
228 
229 	return 0;
230 }
231 
232 /* Switch CPU speed under PMU control
233  */
234 static int pmu_set_cpu_speed(int low_speed)
235 {
236 	struct adb_request req;
237 	unsigned long save_l2cr;
238 	unsigned long save_l3cr;
239 	unsigned int pic_prio;
240 	unsigned long flags;
241 
242 	preempt_disable();
243 
244 #ifdef DEBUG_FREQ
245 	printk(KERN_DEBUG "HID1, before: %x\n", mfspr(SPRN_HID1));
246 #endif
247 	pmu_suspend();
248 
249 	/* Disable all interrupt sources on openpic */
250  	pic_prio = mpic_cpu_get_priority();
251 	mpic_cpu_set_priority(0xf);
252 
253 	/* Make sure the decrementer won't interrupt us */
254 	asm volatile("mtdec %0" : : "r" (0x7fffffff));
255 	/* Make sure any pending DEC interrupt occurring while we did
256 	 * the above didn't re-enable the DEC */
257 	mb();
258 	asm volatile("mtdec %0" : : "r" (0x7fffffff));
259 
260 	/* We can now disable MSR_EE */
261 	local_irq_save(flags);
262 
263 	/* Giveup the FPU & vec */
264 	enable_kernel_fp();
265 
266 #ifdef CONFIG_ALTIVEC
267 	if (cpu_has_feature(CPU_FTR_ALTIVEC))
268 		enable_kernel_altivec();
269 #endif /* CONFIG_ALTIVEC */
270 
271 	/* Save & disable L2 and L3 caches */
272 	save_l3cr = _get_L3CR();	/* (returns -1 if not available) */
273 	save_l2cr = _get_L2CR();	/* (returns -1 if not available) */
274 
275 	/* Send the new speed command. My assumption is that this command
276 	 * will cause PLL_CFG[0..3] to be changed next time CPU goes to sleep
277 	 */
278 	pmu_request(&req, NULL, 6, PMU_CPU_SPEED, 'W', 'O', 'O', 'F', low_speed);
279 	while (!req.complete)
280 		pmu_poll();
281 
282 	/* Prepare the northbridge for the speed transition */
283 	pmac_call_feature(PMAC_FTR_SLEEP_STATE,NULL,1,1);
284 
285 	/* Call low level code to backup CPU state and recover from
286 	 * hardware reset
287 	 */
288 	low_sleep_handler();
289 
290 	/* Restore the northbridge */
291 	pmac_call_feature(PMAC_FTR_SLEEP_STATE,NULL,1,0);
292 
293 	/* Restore L2 cache */
294 	if (save_l2cr != 0xffffffff && (save_l2cr & L2CR_L2E) != 0)
295  		_set_L2CR(save_l2cr);
296 	/* Restore L3 cache */
297 	if (save_l3cr != 0xffffffff && (save_l3cr & L3CR_L3E) != 0)
298  		_set_L3CR(save_l3cr);
299 
300 	/* Restore userland MMU context */
301 	switch_mmu_context(NULL, current->active_mm);
302 
303 #ifdef DEBUG_FREQ
304 	printk(KERN_DEBUG "HID1, after: %x\n", mfspr(SPRN_HID1));
305 #endif
306 
307 	/* Restore low level PMU operations */
308 	pmu_unlock();
309 
310 	/*
311 	 * Restore decrementer; we'll take a decrementer interrupt
312 	 * as soon as interrupts are re-enabled and the generic
313 	 * clockevents code will reprogram it with the right value.
314 	 */
315 	set_dec(1);
316 
317 	/* Restore interrupts */
318  	mpic_cpu_set_priority(pic_prio);
319 
320 	/* Let interrupts flow again ... */
321 	local_irq_restore(flags);
322 
323 #ifdef DEBUG_FREQ
324 	debug_calc_bogomips();
325 #endif
326 
327 	pmu_resume();
328 
329 	preempt_enable();
330 
331 	return 0;
332 }
333 
334 static int do_set_cpu_speed(struct cpufreq_policy *policy, int speed_mode)
335 {
336 	unsigned long l3cr;
337 	static unsigned long prev_l3cr;
338 
339 	if (speed_mode == CPUFREQ_LOW &&
340 	    cpu_has_feature(CPU_FTR_L3CR)) {
341 		l3cr = _get_L3CR();
342 		if (l3cr & L3CR_L3E) {
343 			prev_l3cr = l3cr;
344 			_set_L3CR(0);
345 		}
346 	}
347 	set_speed_proc(speed_mode == CPUFREQ_LOW);
348 	if (speed_mode == CPUFREQ_HIGH &&
349 	    cpu_has_feature(CPU_FTR_L3CR)) {
350 		l3cr = _get_L3CR();
351 		if ((prev_l3cr & L3CR_L3E) && l3cr != prev_l3cr)
352 			_set_L3CR(prev_l3cr);
353 	}
354 	cur_freq = (speed_mode == CPUFREQ_HIGH) ? hi_freq : low_freq;
355 
356 	return 0;
357 }
358 
359 static unsigned int pmac_cpufreq_get_speed(unsigned int cpu)
360 {
361 	return cur_freq;
362 }
363 
364 static int pmac_cpufreq_target(	struct cpufreq_policy *policy,
365 					unsigned int index)
366 {
367 	int		rc;
368 
369 	rc = do_set_cpu_speed(policy, index);
370 
371 	ppc_proc_freq = cur_freq * 1000ul;
372 	return rc;
373 }
374 
375 static int pmac_cpufreq_cpu_init(struct cpufreq_policy *policy)
376 {
377 	return cpufreq_generic_init(policy, pmac_cpu_freqs, transition_latency);
378 }
379 
380 static u32 read_gpio(struct device_node *np)
381 {
382 	const u32 *reg = of_get_property(np, "reg", NULL);
383 	u32 offset;
384 
385 	if (reg == NULL)
386 		return 0;
387 	/* That works for all keylargos but shall be fixed properly
388 	 * some day... The problem is that it seems we can't rely
389 	 * on the "reg" property of the GPIO nodes, they are either
390 	 * relative to the base of KeyLargo or to the base of the
391 	 * GPIO space, and the device-tree doesn't help.
392 	 */
393 	offset = *reg;
394 	if (offset < KEYLARGO_GPIO_LEVELS0)
395 		offset += KEYLARGO_GPIO_LEVELS0;
396 	return offset;
397 }
398 
399 static int pmac_cpufreq_suspend(struct cpufreq_policy *policy)
400 {
401 	/* Ok, this could be made a bit smarter, but let's be robust for now. We
402 	 * always force a speed change to high speed before sleep, to make sure
403 	 * we have appropriate voltage and/or bus speed for the wakeup process,
404 	 * and to make sure our loops_per_jiffies are "good enough", that is will
405 	 * not cause too short delays if we sleep in low speed and wake in high
406 	 * speed..
407 	 */
408 	no_schedule = 1;
409 	sleep_freq = cur_freq;
410 	if (cur_freq == low_freq && !is_pmu_based)
411 		do_set_cpu_speed(policy, CPUFREQ_HIGH);
412 	return 0;
413 }
414 
415 static int pmac_cpufreq_resume(struct cpufreq_policy *policy)
416 {
417 	/* If we resume, first check if we have a get() function */
418 	if (get_speed_proc)
419 		cur_freq = get_speed_proc();
420 	else
421 		cur_freq = 0;
422 
423 	/* We don't, hrm... we don't really know our speed here, best
424 	 * is that we force a switch to whatever it was, which is
425 	 * probably high speed due to our suspend() routine
426 	 */
427 	do_set_cpu_speed(policy, sleep_freq == low_freq ?
428 			 CPUFREQ_LOW : CPUFREQ_HIGH);
429 
430 	ppc_proc_freq = cur_freq * 1000ul;
431 
432 	no_schedule = 0;
433 	return 0;
434 }
435 
436 static struct cpufreq_driver pmac_cpufreq_driver = {
437 	.verify 	= cpufreq_generic_frequency_table_verify,
438 	.target_index	= pmac_cpufreq_target,
439 	.get		= pmac_cpufreq_get_speed,
440 	.init		= pmac_cpufreq_cpu_init,
441 	.suspend	= pmac_cpufreq_suspend,
442 	.resume		= pmac_cpufreq_resume,
443 	.flags		= CPUFREQ_PM_NO_WARN,
444 	.attr		= cpufreq_generic_attr,
445 	.name		= "powermac",
446 };
447 
448 
449 static int pmac_cpufreq_init_MacRISC3(struct device_node *cpunode)
450 {
451 	struct device_node *volt_gpio_np = of_find_node_by_name(NULL,
452 								"voltage-gpio");
453 	struct device_node *freq_gpio_np = of_find_node_by_name(NULL,
454 								"frequency-gpio");
455 	struct device_node *slew_done_gpio_np = of_find_node_by_name(NULL,
456 								     "slewing-done");
457 	const u32 *value;
458 
459 	/*
460 	 * Check to see if it's GPIO driven or PMU only
461 	 *
462 	 * The way we extract the GPIO address is slightly hackish, but it
463 	 * works well enough for now. We need to abstract the whole GPIO
464 	 * stuff sooner or later anyway
465 	 */
466 
467 	if (volt_gpio_np)
468 		voltage_gpio = read_gpio(volt_gpio_np);
469 	if (freq_gpio_np)
470 		frequency_gpio = read_gpio(freq_gpio_np);
471 	if (slew_done_gpio_np)
472 		slew_done_gpio = read_gpio(slew_done_gpio_np);
473 
474 	/* If we use the frequency GPIOs, calculate the min/max speeds based
475 	 * on the bus frequencies
476 	 */
477 	if (frequency_gpio && slew_done_gpio) {
478 		int lenp, rc;
479 		const u32 *freqs, *ratio;
480 
481 		freqs = of_get_property(cpunode, "bus-frequencies", &lenp);
482 		lenp /= sizeof(u32);
483 		if (freqs == NULL || lenp != 2) {
484 			printk(KERN_ERR "cpufreq: bus-frequencies incorrect or missing\n");
485 			return 1;
486 		}
487 		ratio = of_get_property(cpunode, "processor-to-bus-ratio*2",
488 						NULL);
489 		if (ratio == NULL) {
490 			printk(KERN_ERR "cpufreq: processor-to-bus-ratio*2 missing\n");
491 			return 1;
492 		}
493 
494 		/* Get the min/max bus frequencies */
495 		low_freq = min(freqs[0], freqs[1]);
496 		hi_freq = max(freqs[0], freqs[1]);
497 
498 		/* Grrrr.. It _seems_ that the device-tree is lying on the low bus
499 		 * frequency, it claims it to be around 84Mhz on some models while
500 		 * it appears to be approx. 101Mhz on all. Let's hack around here...
501 		 * fortunately, we don't need to be too precise
502 		 */
503 		if (low_freq < 98000000)
504 			low_freq = 101000000;
505 
506 		/* Convert those to CPU core clocks */
507 		low_freq = (low_freq * (*ratio)) / 2000;
508 		hi_freq = (hi_freq * (*ratio)) / 2000;
509 
510 		/* Now we get the frequencies, we read the GPIO to see what is out current
511 		 * speed
512 		 */
513 		rc = pmac_call_feature(PMAC_FTR_READ_GPIO, NULL, frequency_gpio, 0);
514 		cur_freq = (rc & 0x01) ? hi_freq : low_freq;
515 
516 		set_speed_proc = gpios_set_cpu_speed;
517 		return 1;
518 	}
519 
520 	/* If we use the PMU, look for the min & max frequencies in the
521 	 * device-tree
522 	 */
523 	value = of_get_property(cpunode, "min-clock-frequency", NULL);
524 	if (!value)
525 		return 1;
526 	low_freq = (*value) / 1000;
527 	/* The PowerBook G4 12" (PowerBook6,1) has an error in the device-tree
528 	 * here */
529 	if (low_freq < 100000)
530 		low_freq *= 10;
531 
532 	value = of_get_property(cpunode, "max-clock-frequency", NULL);
533 	if (!value)
534 		return 1;
535 	hi_freq = (*value) / 1000;
536 	set_speed_proc = pmu_set_cpu_speed;
537 	is_pmu_based = 1;
538 
539 	return 0;
540 }
541 
542 static int pmac_cpufreq_init_7447A(struct device_node *cpunode)
543 {
544 	struct device_node *volt_gpio_np;
545 
546 	if (of_get_property(cpunode, "dynamic-power-step", NULL) == NULL)
547 		return 1;
548 
549 	volt_gpio_np = of_find_node_by_name(NULL, "cpu-vcore-select");
550 	if (volt_gpio_np)
551 		voltage_gpio = read_gpio(volt_gpio_np);
552 	if (!voltage_gpio){
553 		printk(KERN_ERR "cpufreq: missing cpu-vcore-select gpio\n");
554 		return 1;
555 	}
556 
557 	/* OF only reports the high frequency */
558 	hi_freq = cur_freq;
559 	low_freq = cur_freq/2;
560 
561 	/* Read actual frequency from CPU */
562 	cur_freq = dfs_get_cpu_speed();
563 	set_speed_proc = dfs_set_cpu_speed;
564 	get_speed_proc = dfs_get_cpu_speed;
565 
566 	return 0;
567 }
568 
569 static int pmac_cpufreq_init_750FX(struct device_node *cpunode)
570 {
571 	struct device_node *volt_gpio_np;
572 	u32 pvr;
573 	const u32 *value;
574 
575 	if (of_get_property(cpunode, "dynamic-power-step", NULL) == NULL)
576 		return 1;
577 
578 	hi_freq = cur_freq;
579 	value = of_get_property(cpunode, "reduced-clock-frequency", NULL);
580 	if (!value)
581 		return 1;
582 	low_freq = (*value) / 1000;
583 
584 	volt_gpio_np = of_find_node_by_name(NULL, "cpu-vcore-select");
585 	if (volt_gpio_np)
586 		voltage_gpio = read_gpio(volt_gpio_np);
587 
588 	pvr = mfspr(SPRN_PVR);
589 	has_cpu_l2lve = !((pvr & 0xf00) == 0x100);
590 
591 	set_speed_proc = cpu_750fx_cpu_speed;
592 	get_speed_proc = cpu_750fx_get_cpu_speed;
593 	cur_freq = cpu_750fx_get_cpu_speed();
594 
595 	return 0;
596 }
597 
598 /* Currently, we support the following machines:
599  *
600  *  - Titanium PowerBook 1Ghz (PMU based, 667Mhz & 1Ghz)
601  *  - Titanium PowerBook 800 (PMU based, 667Mhz & 800Mhz)
602  *  - Titanium PowerBook 400 (PMU based, 300Mhz & 400Mhz)
603  *  - Titanium PowerBook 500 (PMU based, 300Mhz & 500Mhz)
604  *  - iBook2 500/600 (PMU based, 400Mhz & 500/600Mhz)
605  *  - iBook2 700 (CPU based, 400Mhz & 700Mhz, support low voltage)
606  *  - Recent MacRISC3 laptops
607  *  - All new machines with 7447A CPUs
608  */
609 static int __init pmac_cpufreq_setup(void)
610 {
611 	struct device_node	*cpunode;
612 	const u32		*value;
613 
614 	if (strstr(boot_command_line, "nocpufreq"))
615 		return 0;
616 
617 	/* Get first CPU node */
618 	cpunode = of_cpu_device_node_get(0);
619 	if (!cpunode)
620 		goto out;
621 
622 	/* Get current cpu clock freq */
623 	value = of_get_property(cpunode, "clock-frequency", NULL);
624 	if (!value)
625 		goto out;
626 	cur_freq = (*value) / 1000;
627 	transition_latency = CPUFREQ_ETERNAL;
628 
629 	/*  Check for 7447A based MacRISC3 */
630 	if (of_machine_is_compatible("MacRISC3") &&
631 	    of_get_property(cpunode, "dynamic-power-step", NULL) &&
632 	    PVR_VER(mfspr(SPRN_PVR)) == 0x8003) {
633 		pmac_cpufreq_init_7447A(cpunode);
634 		transition_latency = 8000000;
635 	/* Check for other MacRISC3 machines */
636 	} else if (of_machine_is_compatible("PowerBook3,4") ||
637 		   of_machine_is_compatible("PowerBook3,5") ||
638 		   of_machine_is_compatible("MacRISC3")) {
639 		pmac_cpufreq_init_MacRISC3(cpunode);
640 	/* Else check for iBook2 500/600 */
641 	} else if (of_machine_is_compatible("PowerBook4,1")) {
642 		hi_freq = cur_freq;
643 		low_freq = 400000;
644 		set_speed_proc = pmu_set_cpu_speed;
645 		is_pmu_based = 1;
646 	}
647 	/* Else check for TiPb 550 */
648 	else if (of_machine_is_compatible("PowerBook3,3") && cur_freq == 550000) {
649 		hi_freq = cur_freq;
650 		low_freq = 500000;
651 		set_speed_proc = pmu_set_cpu_speed;
652 		is_pmu_based = 1;
653 	}
654 	/* Else check for TiPb 400 & 500 */
655 	else if (of_machine_is_compatible("PowerBook3,2")) {
656 		/* We only know about the 400 MHz and the 500Mhz model
657 		 * they both have 300 MHz as low frequency
658 		 */
659 		if (cur_freq < 350000 || cur_freq > 550000)
660 			goto out;
661 		hi_freq = cur_freq;
662 		low_freq = 300000;
663 		set_speed_proc = pmu_set_cpu_speed;
664 		is_pmu_based = 1;
665 	}
666 	/* Else check for 750FX */
667 	else if (PVR_VER(mfspr(SPRN_PVR)) == 0x7000)
668 		pmac_cpufreq_init_750FX(cpunode);
669 out:
670 	of_node_put(cpunode);
671 	if (set_speed_proc == NULL)
672 		return -ENODEV;
673 
674 	pmac_cpu_freqs[CPUFREQ_LOW].frequency = low_freq;
675 	pmac_cpu_freqs[CPUFREQ_HIGH].frequency = hi_freq;
676 	ppc_proc_freq = cur_freq * 1000ul;
677 
678 	printk(KERN_INFO "Registering PowerMac CPU frequency driver\n");
679 	printk(KERN_INFO "Low: %d Mhz, High: %d Mhz, Boot: %d Mhz\n",
680 	       low_freq/1000, hi_freq/1000, cur_freq/1000);
681 
682 	return cpufreq_register_driver(&pmac_cpufreq_driver);
683 }
684 
685 module_init(pmac_cpufreq_setup);
686 
687