xref: /linux/drivers/cpufreq/pmac64-cpufreq.c (revision c4ee0af3fa0dc65f690fc908f02b8355f9576ea0)
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 <linux/of_device.h>
26 #include <asm/prom.h>
27 #include <asm/machdep.h>
28 #include <asm/irq.h>
29 #include <asm/sections.h>
30 #include <asm/cputable.h>
31 #include <asm/time.h>
32 #include <asm/smu.h>
33 #include <asm/pmac_pfunc.h>
34 
35 #define DBG(fmt...) pr_debug(fmt)
36 
37 /* see 970FX user manual */
38 
39 #define SCOM_PCR 0x0aa001			/* PCR scom addr */
40 
41 #define PCR_HILO_SELECT		0x80000000U	/* 1 = PCR, 0 = PCRH */
42 #define PCR_SPEED_FULL		0x00000000U	/* 1:1 speed value */
43 #define PCR_SPEED_HALF		0x00020000U	/* 1:2 speed value */
44 #define PCR_SPEED_QUARTER	0x00040000U	/* 1:4 speed value */
45 #define PCR_SPEED_MASK		0x000e0000U	/* speed mask */
46 #define PCR_SPEED_SHIFT		17
47 #define PCR_FREQ_REQ_VALID	0x00010000U	/* freq request valid */
48 #define PCR_VOLT_REQ_VALID	0x00008000U	/* volt request valid */
49 #define PCR_TARGET_TIME_MASK	0x00006000U	/* target time */
50 #define PCR_STATLAT_MASK	0x00001f00U	/* STATLAT value */
51 #define PCR_SNOOPLAT_MASK	0x000000f0U	/* SNOOPLAT value */
52 #define PCR_SNOOPACC_MASK	0x0000000fU	/* SNOOPACC value */
53 
54 #define SCOM_PSR 0x408001			/* PSR scom addr */
55 /* warning: PSR is a 64 bits register */
56 #define PSR_CMD_RECEIVED	0x2000000000000000U   /* command received */
57 #define PSR_CMD_COMPLETED	0x1000000000000000U   /* command completed */
58 #define PSR_CUR_SPEED_MASK	0x0300000000000000U   /* current speed */
59 #define PSR_CUR_SPEED_SHIFT	(56)
60 
61 /*
62  * The G5 only supports two frequencies (Quarter speed is not supported)
63  */
64 #define CPUFREQ_HIGH                  0
65 #define CPUFREQ_LOW                   1
66 
67 static struct cpufreq_frequency_table g5_cpu_freqs[] = {
68 	{CPUFREQ_HIGH, 		0},
69 	{CPUFREQ_LOW,		0},
70 	{0,			CPUFREQ_TABLE_END},
71 };
72 
73 /* Power mode data is an array of the 32 bits PCR values to use for
74  * the various frequencies, retrieved from the device-tree
75  */
76 static int g5_pmode_cur;
77 
78 static void (*g5_switch_volt)(int speed_mode);
79 static int (*g5_switch_freq)(int speed_mode);
80 static int (*g5_query_freq)(void);
81 
82 static unsigned long transition_latency;
83 
84 #ifdef CONFIG_PMAC_SMU
85 
86 static const u32 *g5_pmode_data;
87 static int g5_pmode_max;
88 
89 static struct smu_sdbp_fvt *g5_fvt_table;	/* table of op. points */
90 static int g5_fvt_count;			/* number of op. points */
91 static int g5_fvt_cur;				/* current op. point */
92 
93 /*
94  * SMU based voltage switching for Neo2 platforms
95  */
96 
97 static void g5_smu_switch_volt(int speed_mode)
98 {
99 	struct smu_simple_cmd	cmd;
100 
101 	DECLARE_COMPLETION_ONSTACK(comp);
102 	smu_queue_simple(&cmd, SMU_CMD_POWER_COMMAND, 8, smu_done_complete,
103 			 &comp, 'V', 'S', 'L', 'E', 'W',
104 			 0xff, g5_fvt_cur+1, speed_mode);
105 	wait_for_completion(&comp);
106 }
107 
108 /*
109  * Platform function based voltage/vdnap switching for Neo2
110  */
111 
112 static struct pmf_function *pfunc_set_vdnap0;
113 static struct pmf_function *pfunc_vdnap0_complete;
114 
115 static void g5_vdnap_switch_volt(int speed_mode)
116 {
117 	struct pmf_args args;
118 	u32 slew, done = 0;
119 	unsigned long timeout;
120 
121 	slew = (speed_mode == CPUFREQ_LOW) ? 1 : 0;
122 	args.count = 1;
123 	args.u[0].p = &slew;
124 
125 	pmf_call_one(pfunc_set_vdnap0, &args);
126 
127 	/* It's an irq GPIO so we should be able to just block here,
128 	 * I'll do that later after I've properly tested the IRQ code for
129 	 * platform functions
130 	 */
131 	timeout = jiffies + HZ/10;
132 	while(!time_after(jiffies, timeout)) {
133 		args.count = 1;
134 		args.u[0].p = &done;
135 		pmf_call_one(pfunc_vdnap0_complete, &args);
136 		if (done)
137 			break;
138 		usleep_range(1000, 1000);
139 	}
140 	if (done == 0)
141 		printk(KERN_WARNING "cpufreq: Timeout in clock slewing !\n");
142 }
143 
144 
145 /*
146  * SCOM based frequency switching for 970FX rev3
147  */
148 static int g5_scom_switch_freq(int speed_mode)
149 {
150 	unsigned long flags;
151 	int to;
152 
153 	/* If frequency is going up, first ramp up the voltage */
154 	if (speed_mode < g5_pmode_cur)
155 		g5_switch_volt(speed_mode);
156 
157 	local_irq_save(flags);
158 
159 	/* Clear PCR high */
160 	scom970_write(SCOM_PCR, 0);
161 	/* Clear PCR low */
162        	scom970_write(SCOM_PCR, PCR_HILO_SELECT | 0);
163 	/* Set PCR low */
164 	scom970_write(SCOM_PCR, PCR_HILO_SELECT |
165 		      g5_pmode_data[speed_mode]);
166 
167 	/* Wait for completion */
168 	for (to = 0; to < 10; to++) {
169 		unsigned long psr = scom970_read(SCOM_PSR);
170 
171 		if ((psr & PSR_CMD_RECEIVED) == 0 &&
172 		    (((psr >> PSR_CUR_SPEED_SHIFT) ^
173 		      (g5_pmode_data[speed_mode] >> PCR_SPEED_SHIFT)) & 0x3)
174 		    == 0)
175 			break;
176 		if (psr & PSR_CMD_COMPLETED)
177 			break;
178 		udelay(100);
179 	}
180 
181 	local_irq_restore(flags);
182 
183 	/* If frequency is going down, last ramp the voltage */
184 	if (speed_mode > g5_pmode_cur)
185 		g5_switch_volt(speed_mode);
186 
187 	g5_pmode_cur = speed_mode;
188 	ppc_proc_freq = g5_cpu_freqs[speed_mode].frequency * 1000ul;
189 
190 	return 0;
191 }
192 
193 static int g5_scom_query_freq(void)
194 {
195 	unsigned long psr = scom970_read(SCOM_PSR);
196 	int i;
197 
198 	for (i = 0; i <= g5_pmode_max; i++)
199 		if ((((psr >> PSR_CUR_SPEED_SHIFT) ^
200 		      (g5_pmode_data[i] >> PCR_SPEED_SHIFT)) & 0x3) == 0)
201 			break;
202 	return i;
203 }
204 
205 /*
206  * Fake voltage switching for platforms with missing support
207  */
208 
209 static void g5_dummy_switch_volt(int speed_mode)
210 {
211 }
212 
213 #endif /* CONFIG_PMAC_SMU */
214 
215 /*
216  * Platform function based voltage switching for PowerMac7,2 & 7,3
217  */
218 
219 static struct pmf_function *pfunc_cpu0_volt_high;
220 static struct pmf_function *pfunc_cpu0_volt_low;
221 static struct pmf_function *pfunc_cpu1_volt_high;
222 static struct pmf_function *pfunc_cpu1_volt_low;
223 
224 static void g5_pfunc_switch_volt(int speed_mode)
225 {
226 	if (speed_mode == CPUFREQ_HIGH) {
227 		if (pfunc_cpu0_volt_high)
228 			pmf_call_one(pfunc_cpu0_volt_high, NULL);
229 		if (pfunc_cpu1_volt_high)
230 			pmf_call_one(pfunc_cpu1_volt_high, NULL);
231 	} else {
232 		if (pfunc_cpu0_volt_low)
233 			pmf_call_one(pfunc_cpu0_volt_low, NULL);
234 		if (pfunc_cpu1_volt_low)
235 			pmf_call_one(pfunc_cpu1_volt_low, NULL);
236 	}
237 	usleep_range(10000, 10000); /* should be faster , to fix */
238 }
239 
240 /*
241  * Platform function based frequency switching for PowerMac7,2 & 7,3
242  */
243 
244 static struct pmf_function *pfunc_cpu_setfreq_high;
245 static struct pmf_function *pfunc_cpu_setfreq_low;
246 static struct pmf_function *pfunc_cpu_getfreq;
247 static struct pmf_function *pfunc_slewing_done;
248 
249 static int g5_pfunc_switch_freq(int speed_mode)
250 {
251 	struct pmf_args args;
252 	u32 done = 0;
253 	unsigned long timeout;
254 	int rc;
255 
256 	DBG("g5_pfunc_switch_freq(%d)\n", speed_mode);
257 
258 	/* If frequency is going up, first ramp up the voltage */
259 	if (speed_mode < g5_pmode_cur)
260 		g5_switch_volt(speed_mode);
261 
262 	/* Do it */
263 	if (speed_mode == CPUFREQ_HIGH)
264 		rc = pmf_call_one(pfunc_cpu_setfreq_high, NULL);
265 	else
266 		rc = pmf_call_one(pfunc_cpu_setfreq_low, NULL);
267 
268 	if (rc)
269 		printk(KERN_WARNING "cpufreq: pfunc switch error %d\n", rc);
270 
271 	/* It's an irq GPIO so we should be able to just block here,
272 	 * I'll do that later after I've properly tested the IRQ code for
273 	 * platform functions
274 	 */
275 	timeout = jiffies + HZ/10;
276 	while(!time_after(jiffies, timeout)) {
277 		args.count = 1;
278 		args.u[0].p = &done;
279 		pmf_call_one(pfunc_slewing_done, &args);
280 		if (done)
281 			break;
282 		usleep_range(500, 500);
283 	}
284 	if (done == 0)
285 		printk(KERN_WARNING "cpufreq: Timeout in clock slewing !\n");
286 
287 	/* If frequency is going down, last ramp the voltage */
288 	if (speed_mode > g5_pmode_cur)
289 		g5_switch_volt(speed_mode);
290 
291 	g5_pmode_cur = speed_mode;
292 	ppc_proc_freq = g5_cpu_freqs[speed_mode].frequency * 1000ul;
293 
294 	return 0;
295 }
296 
297 static int g5_pfunc_query_freq(void)
298 {
299 	struct pmf_args args;
300 	u32 val = 0;
301 
302 	args.count = 1;
303 	args.u[0].p = &val;
304 	pmf_call_one(pfunc_cpu_getfreq, &args);
305 	return val ? CPUFREQ_HIGH : CPUFREQ_LOW;
306 }
307 
308 
309 /*
310  * Common interface to the cpufreq core
311  */
312 
313 static int g5_cpufreq_target(struct cpufreq_policy *policy, unsigned int index)
314 {
315 	return g5_switch_freq(index);
316 }
317 
318 static unsigned int g5_cpufreq_get_speed(unsigned int cpu)
319 {
320 	return g5_cpu_freqs[g5_pmode_cur].frequency;
321 }
322 
323 static int g5_cpufreq_cpu_init(struct cpufreq_policy *policy)
324 {
325 	return cpufreq_generic_init(policy, g5_cpu_freqs, transition_latency);
326 }
327 
328 static struct cpufreq_driver g5_cpufreq_driver = {
329 	.name		= "powermac",
330 	.flags		= CPUFREQ_CONST_LOOPS,
331 	.init		= g5_cpufreq_cpu_init,
332 	.verify		= cpufreq_generic_frequency_table_verify,
333 	.target_index	= g5_cpufreq_target,
334 	.get		= g5_cpufreq_get_speed,
335 	.attr 		= cpufreq_generic_attr,
336 };
337 
338 
339 #ifdef CONFIG_PMAC_SMU
340 
341 static int __init g5_neo2_cpufreq_init(struct device_node *cpunode)
342 {
343 	unsigned int psize, ssize;
344 	unsigned long max_freq;
345 	char *freq_method, *volt_method;
346 	const u32 *valp;
347 	u32 pvr_hi;
348 	int use_volts_vdnap = 0;
349 	int use_volts_smu = 0;
350 	int rc = -ENODEV;
351 
352 	/* Check supported platforms */
353 	if (of_machine_is_compatible("PowerMac8,1") ||
354 	    of_machine_is_compatible("PowerMac8,2") ||
355 	    of_machine_is_compatible("PowerMac9,1") ||
356 	    of_machine_is_compatible("PowerMac12,1"))
357 		use_volts_smu = 1;
358 	else if (of_machine_is_compatible("PowerMac11,2"))
359 		use_volts_vdnap = 1;
360 	else
361 		return -ENODEV;
362 
363 	/* Check 970FX for now */
364 	valp = of_get_property(cpunode, "cpu-version", NULL);
365 	if (!valp) {
366 		DBG("No cpu-version property !\n");
367 		goto bail_noprops;
368 	}
369 	pvr_hi = (*valp) >> 16;
370 	if (pvr_hi != 0x3c && pvr_hi != 0x44) {
371 		printk(KERN_ERR "cpufreq: Unsupported CPU version\n");
372 		goto bail_noprops;
373 	}
374 
375 	/* Look for the powertune data in the device-tree */
376 	g5_pmode_data = of_get_property(cpunode, "power-mode-data",&psize);
377 	if (!g5_pmode_data) {
378 		DBG("No power-mode-data !\n");
379 		goto bail_noprops;
380 	}
381 	g5_pmode_max = psize / sizeof(u32) - 1;
382 
383 	if (use_volts_smu) {
384 		const struct smu_sdbp_header *shdr;
385 
386 		/* Look for the FVT table */
387 		shdr = smu_get_sdb_partition(SMU_SDB_FVT_ID, NULL);
388 		if (!shdr)
389 			goto bail_noprops;
390 		g5_fvt_table = (struct smu_sdbp_fvt *)&shdr[1];
391 		ssize = (shdr->len * sizeof(u32)) - sizeof(*shdr);
392 		g5_fvt_count = ssize / sizeof(*g5_fvt_table);
393 		g5_fvt_cur = 0;
394 
395 		/* Sanity checking */
396 		if (g5_fvt_count < 1 || g5_pmode_max < 1)
397 			goto bail_noprops;
398 
399 		g5_switch_volt = g5_smu_switch_volt;
400 		volt_method = "SMU";
401 	} else if (use_volts_vdnap) {
402 		struct device_node *root;
403 
404 		root = of_find_node_by_path("/");
405 		if (root == NULL) {
406 			printk(KERN_ERR "cpufreq: Can't find root of "
407 			       "device tree\n");
408 			goto bail_noprops;
409 		}
410 		pfunc_set_vdnap0 = pmf_find_function(root, "set-vdnap0");
411 		pfunc_vdnap0_complete =
412 			pmf_find_function(root, "slewing-done");
413 		if (pfunc_set_vdnap0 == NULL ||
414 		    pfunc_vdnap0_complete == NULL) {
415 			printk(KERN_ERR "cpufreq: Can't find required "
416 			       "platform function\n");
417 			goto bail_noprops;
418 		}
419 
420 		g5_switch_volt = g5_vdnap_switch_volt;
421 		volt_method = "GPIO";
422 	} else {
423 		g5_switch_volt = g5_dummy_switch_volt;
424 		volt_method = "none";
425 	}
426 
427 	/*
428 	 * From what I see, clock-frequency is always the maximal frequency.
429 	 * The current driver can not slew sysclk yet, so we really only deal
430 	 * with powertune steps for now. We also only implement full freq and
431 	 * half freq in this version. So far, I haven't yet seen a machine
432 	 * supporting anything else.
433 	 */
434 	valp = of_get_property(cpunode, "clock-frequency", NULL);
435 	if (!valp)
436 		return -ENODEV;
437 	max_freq = (*valp)/1000;
438 	g5_cpu_freqs[0].frequency = max_freq;
439 	g5_cpu_freqs[1].frequency = max_freq/2;
440 
441 	/* Set callbacks */
442 	transition_latency = 12000;
443 	g5_switch_freq = g5_scom_switch_freq;
444 	g5_query_freq = g5_scom_query_freq;
445 	freq_method = "SCOM";
446 
447 	/* Force apply current frequency to make sure everything is in
448 	 * sync (voltage is right for example). Firmware may leave us with
449 	 * a strange setting ...
450 	 */
451 	g5_switch_volt(CPUFREQ_HIGH);
452 	msleep(10);
453 	g5_pmode_cur = -1;
454 	g5_switch_freq(g5_query_freq());
455 
456 	printk(KERN_INFO "Registering G5 CPU frequency driver\n");
457 	printk(KERN_INFO "Frequency method: %s, Voltage method: %s\n",
458 	       freq_method, volt_method);
459 	printk(KERN_INFO "Low: %d Mhz, High: %d Mhz, Cur: %d MHz\n",
460 		g5_cpu_freqs[1].frequency/1000,
461 		g5_cpu_freqs[0].frequency/1000,
462 		g5_cpu_freqs[g5_pmode_cur].frequency/1000);
463 
464 	rc = cpufreq_register_driver(&g5_cpufreq_driver);
465 
466 	/* We keep the CPU node on hold... hopefully, Apple G5 don't have
467 	 * hotplug CPU with a dynamic device-tree ...
468 	 */
469 	return rc;
470 
471  bail_noprops:
472 	of_node_put(cpunode);
473 
474 	return rc;
475 }
476 
477 #endif /* CONFIG_PMAC_SMU */
478 
479 
480 static int __init g5_pm72_cpufreq_init(struct device_node *cpunode)
481 {
482 	struct device_node *cpuid = NULL, *hwclock = NULL;
483 	const u8 *eeprom = NULL;
484 	const u32 *valp;
485 	u64 max_freq, min_freq, ih, il;
486 	int has_volt = 1, rc = 0;
487 
488 	DBG("cpufreq: Initializing for PowerMac7,2, PowerMac7,3 and"
489 	    " RackMac3,1...\n");
490 
491 	/* Lookup the cpuid eeprom node */
492         cpuid = of_find_node_by_path("/u3@0,f8000000/i2c@f8001000/cpuid@a0");
493 	if (cpuid != NULL)
494 		eeprom = of_get_property(cpuid, "cpuid", NULL);
495 	if (eeprom == NULL) {
496 		printk(KERN_ERR "cpufreq: Can't find cpuid EEPROM !\n");
497 		rc = -ENODEV;
498 		goto bail;
499 	}
500 
501 	/* Lookup the i2c hwclock */
502 	for (hwclock = NULL;
503 	     (hwclock = of_find_node_by_name(hwclock, "i2c-hwclock")) != NULL;){
504 		const char *loc = of_get_property(hwclock,
505 				"hwctrl-location", NULL);
506 		if (loc == NULL)
507 			continue;
508 		if (strcmp(loc, "CPU CLOCK"))
509 			continue;
510 		if (!of_get_property(hwclock, "platform-get-frequency", NULL))
511 			continue;
512 		break;
513 	}
514 	if (hwclock == NULL) {
515 		printk(KERN_ERR "cpufreq: Can't find i2c clock chip !\n");
516 		rc = -ENODEV;
517 		goto bail;
518 	}
519 
520 	DBG("cpufreq: i2c clock chip found: %s\n", hwclock->full_name);
521 
522 	/* Now get all the platform functions */
523 	pfunc_cpu_getfreq =
524 		pmf_find_function(hwclock, "get-frequency");
525 	pfunc_cpu_setfreq_high =
526 		pmf_find_function(hwclock, "set-frequency-high");
527 	pfunc_cpu_setfreq_low =
528 		pmf_find_function(hwclock, "set-frequency-low");
529 	pfunc_slewing_done =
530 		pmf_find_function(hwclock, "slewing-done");
531 	pfunc_cpu0_volt_high =
532 		pmf_find_function(hwclock, "set-voltage-high-0");
533 	pfunc_cpu0_volt_low =
534 		pmf_find_function(hwclock, "set-voltage-low-0");
535 	pfunc_cpu1_volt_high =
536 		pmf_find_function(hwclock, "set-voltage-high-1");
537 	pfunc_cpu1_volt_low =
538 		pmf_find_function(hwclock, "set-voltage-low-1");
539 
540 	/* Check we have minimum requirements */
541 	if (pfunc_cpu_getfreq == NULL || pfunc_cpu_setfreq_high == NULL ||
542 	    pfunc_cpu_setfreq_low == NULL || pfunc_slewing_done == NULL) {
543 		printk(KERN_ERR "cpufreq: Can't find platform functions !\n");
544 		rc = -ENODEV;
545 		goto bail;
546 	}
547 
548 	/* Check that we have complete sets */
549 	if (pfunc_cpu0_volt_high == NULL || pfunc_cpu0_volt_low == NULL) {
550 		pmf_put_function(pfunc_cpu0_volt_high);
551 		pmf_put_function(pfunc_cpu0_volt_low);
552 		pfunc_cpu0_volt_high = pfunc_cpu0_volt_low = NULL;
553 		has_volt = 0;
554 	}
555 	if (!has_volt ||
556 	    pfunc_cpu1_volt_high == NULL || pfunc_cpu1_volt_low == NULL) {
557 		pmf_put_function(pfunc_cpu1_volt_high);
558 		pmf_put_function(pfunc_cpu1_volt_low);
559 		pfunc_cpu1_volt_high = pfunc_cpu1_volt_low = NULL;
560 	}
561 
562 	/* Note: The device tree also contains a "platform-set-values"
563 	 * function for which I haven't quite figured out the usage. It
564 	 * might have to be called on init and/or wakeup, I'm not too sure
565 	 * but things seem to work fine without it so far ...
566 	 */
567 
568 	/* Get max frequency from device-tree */
569 	valp = of_get_property(cpunode, "clock-frequency", NULL);
570 	if (!valp) {
571 		printk(KERN_ERR "cpufreq: Can't find CPU frequency !\n");
572 		rc = -ENODEV;
573 		goto bail;
574 	}
575 
576 	max_freq = (*valp)/1000;
577 
578 	/* Now calculate reduced frequency by using the cpuid input freq
579 	 * ratio. This requires 64 bits math unless we are willing to lose
580 	 * some precision
581 	 */
582 	ih = *((u32 *)(eeprom + 0x10));
583 	il = *((u32 *)(eeprom + 0x20));
584 
585 	/* Check for machines with no useful settings */
586 	if (il == ih) {
587 		printk(KERN_WARNING "cpufreq: No low frequency mode available"
588 		       " on this model !\n");
589 		rc = -ENODEV;
590 		goto bail;
591 	}
592 
593 	min_freq = 0;
594 	if (ih != 0 && il != 0)
595 		min_freq = (max_freq * il) / ih;
596 
597 	/* Sanity check */
598 	if (min_freq >= max_freq || min_freq < 1000) {
599 		printk(KERN_ERR "cpufreq: Can't calculate low frequency !\n");
600 		rc = -ENXIO;
601 		goto bail;
602 	}
603 	g5_cpu_freqs[0].frequency = max_freq;
604 	g5_cpu_freqs[1].frequency = min_freq;
605 
606 	/* Based on a measurement on Xserve G5, rounded up. */
607 	transition_latency = 10 * NSEC_PER_MSEC;
608 
609 	/* Set callbacks */
610 	g5_switch_volt = g5_pfunc_switch_volt;
611 	g5_switch_freq = g5_pfunc_switch_freq;
612 	g5_query_freq = g5_pfunc_query_freq;
613 
614 	/* Force apply current frequency to make sure everything is in
615 	 * sync (voltage is right for example). Firmware may leave us with
616 	 * a strange setting ...
617 	 */
618 	g5_switch_volt(CPUFREQ_HIGH);
619 	msleep(10);
620 	g5_pmode_cur = -1;
621 	g5_switch_freq(g5_query_freq());
622 
623 	printk(KERN_INFO "Registering G5 CPU frequency driver\n");
624 	printk(KERN_INFO "Frequency method: i2c/pfunc, "
625 	       "Voltage method: %s\n", has_volt ? "i2c/pfunc" : "none");
626 	printk(KERN_INFO "Low: %d Mhz, High: %d Mhz, Cur: %d MHz\n",
627 		g5_cpu_freqs[1].frequency/1000,
628 		g5_cpu_freqs[0].frequency/1000,
629 		g5_cpu_freqs[g5_pmode_cur].frequency/1000);
630 
631 	rc = cpufreq_register_driver(&g5_cpufreq_driver);
632  bail:
633 	if (rc != 0) {
634 		pmf_put_function(pfunc_cpu_getfreq);
635 		pmf_put_function(pfunc_cpu_setfreq_high);
636 		pmf_put_function(pfunc_cpu_setfreq_low);
637 		pmf_put_function(pfunc_slewing_done);
638 		pmf_put_function(pfunc_cpu0_volt_high);
639 		pmf_put_function(pfunc_cpu0_volt_low);
640 		pmf_put_function(pfunc_cpu1_volt_high);
641 		pmf_put_function(pfunc_cpu1_volt_low);
642 	}
643 	of_node_put(hwclock);
644 	of_node_put(cpuid);
645 	of_node_put(cpunode);
646 
647 	return rc;
648 }
649 
650 static int __init g5_cpufreq_init(void)
651 {
652 	struct device_node *cpunode;
653 	int rc = 0;
654 
655 	/* Get first CPU node */
656 	cpunode = of_cpu_device_node_get(0);
657 	if (cpunode == NULL) {
658 		pr_err("cpufreq: Can't find any CPU node\n");
659 		return -ENODEV;
660 	}
661 
662 	if (of_machine_is_compatible("PowerMac7,2") ||
663 	    of_machine_is_compatible("PowerMac7,3") ||
664 	    of_machine_is_compatible("RackMac3,1"))
665 		rc = g5_pm72_cpufreq_init(cpunode);
666 #ifdef CONFIG_PMAC_SMU
667 	else
668 		rc = g5_neo2_cpufreq_init(cpunode);
669 #endif /* CONFIG_PMAC_SMU */
670 
671 	return rc;
672 }
673 
674 module_init(g5_cpufreq_init);
675 
676 
677 MODULE_LICENSE("GPL");
678