xref: /linux/drivers/cpufreq/pmac64-cpufreq.c (revision e5c86679d5e864947a52fb31e45a425dea3e7fa9)
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 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
16 
17 #include <linux/module.h>
18 #include <linux/types.h>
19 #include <linux/errno.h>
20 #include <linux/kernel.h>
21 #include <linux/delay.h>
22 #include <linux/sched.h>
23 #include <linux/cpufreq.h>
24 #include <linux/init.h>
25 #include <linux/completion.h>
26 #include <linux/mutex.h>
27 #include <linux/of_device.h>
28 #include <asm/prom.h>
29 #include <asm/machdep.h>
30 #include <asm/irq.h>
31 #include <asm/sections.h>
32 #include <asm/cputable.h>
33 #include <asm/time.h>
34 #include <asm/smu.h>
35 #include <asm/pmac_pfunc.h>
36 
37 #define DBG(fmt...) pr_debug(fmt)
38 
39 /* see 970FX user manual */
40 
41 #define SCOM_PCR 0x0aa001			/* PCR scom addr */
42 
43 #define PCR_HILO_SELECT		0x80000000U	/* 1 = PCR, 0 = PCRH */
44 #define PCR_SPEED_FULL		0x00000000U	/* 1:1 speed value */
45 #define PCR_SPEED_HALF		0x00020000U	/* 1:2 speed value */
46 #define PCR_SPEED_QUARTER	0x00040000U	/* 1:4 speed value */
47 #define PCR_SPEED_MASK		0x000e0000U	/* speed mask */
48 #define PCR_SPEED_SHIFT		17
49 #define PCR_FREQ_REQ_VALID	0x00010000U	/* freq request valid */
50 #define PCR_VOLT_REQ_VALID	0x00008000U	/* volt request valid */
51 #define PCR_TARGET_TIME_MASK	0x00006000U	/* target time */
52 #define PCR_STATLAT_MASK	0x00001f00U	/* STATLAT value */
53 #define PCR_SNOOPLAT_MASK	0x000000f0U	/* SNOOPLAT value */
54 #define PCR_SNOOPACC_MASK	0x0000000fU	/* SNOOPACC value */
55 
56 #define SCOM_PSR 0x408001			/* PSR scom addr */
57 /* warning: PSR is a 64 bits register */
58 #define PSR_CMD_RECEIVED	0x2000000000000000U   /* command received */
59 #define PSR_CMD_COMPLETED	0x1000000000000000U   /* command completed */
60 #define PSR_CUR_SPEED_MASK	0x0300000000000000U   /* current speed */
61 #define PSR_CUR_SPEED_SHIFT	(56)
62 
63 /*
64  * The G5 only supports two frequencies (Quarter speed is not supported)
65  */
66 #define CPUFREQ_HIGH                  0
67 #define CPUFREQ_LOW                   1
68 
69 static struct cpufreq_frequency_table g5_cpu_freqs[] = {
70 	{0, CPUFREQ_HIGH,	0},
71 	{0, CPUFREQ_LOW,	0},
72 	{0, 0,			CPUFREQ_TABLE_END},
73 };
74 
75 /* Power mode data is an array of the 32 bits PCR values to use for
76  * the various frequencies, retrieved from the device-tree
77  */
78 static int g5_pmode_cur;
79 
80 static void (*g5_switch_volt)(int speed_mode);
81 static int (*g5_switch_freq)(int speed_mode);
82 static int (*g5_query_freq)(void);
83 
84 static unsigned long transition_latency;
85 
86 #ifdef CONFIG_PMAC_SMU
87 
88 static const u32 *g5_pmode_data;
89 static int g5_pmode_max;
90 
91 static struct smu_sdbp_fvt *g5_fvt_table;	/* table of op. points */
92 static int g5_fvt_count;			/* number of op. points */
93 static int g5_fvt_cur;				/* current op. point */
94 
95 /*
96  * SMU based voltage switching for Neo2 platforms
97  */
98 
99 static void g5_smu_switch_volt(int speed_mode)
100 {
101 	struct smu_simple_cmd	cmd;
102 
103 	DECLARE_COMPLETION_ONSTACK(comp);
104 	smu_queue_simple(&cmd, SMU_CMD_POWER_COMMAND, 8, smu_done_complete,
105 			 &comp, 'V', 'S', 'L', 'E', 'W',
106 			 0xff, g5_fvt_cur+1, speed_mode);
107 	wait_for_completion(&comp);
108 }
109 
110 /*
111  * Platform function based voltage/vdnap switching for Neo2
112  */
113 
114 static struct pmf_function *pfunc_set_vdnap0;
115 static struct pmf_function *pfunc_vdnap0_complete;
116 
117 static void g5_vdnap_switch_volt(int speed_mode)
118 {
119 	struct pmf_args args;
120 	u32 slew, done = 0;
121 	unsigned long timeout;
122 
123 	slew = (speed_mode == CPUFREQ_LOW) ? 1 : 0;
124 	args.count = 1;
125 	args.u[0].p = &slew;
126 
127 	pmf_call_one(pfunc_set_vdnap0, &args);
128 
129 	/* It's an irq GPIO so we should be able to just block here,
130 	 * I'll do that later after I've properly tested the IRQ code for
131 	 * platform functions
132 	 */
133 	timeout = jiffies + HZ/10;
134 	while(!time_after(jiffies, timeout)) {
135 		args.count = 1;
136 		args.u[0].p = &done;
137 		pmf_call_one(pfunc_vdnap0_complete, &args);
138 		if (done)
139 			break;
140 		usleep_range(1000, 1000);
141 	}
142 	if (done == 0)
143 		pr_warn("Timeout in clock slewing !\n");
144 }
145 
146 
147 /*
148  * SCOM based frequency switching for 970FX rev3
149  */
150 static int g5_scom_switch_freq(int speed_mode)
151 {
152 	unsigned long flags;
153 	int to;
154 
155 	/* If frequency is going up, first ramp up the voltage */
156 	if (speed_mode < g5_pmode_cur)
157 		g5_switch_volt(speed_mode);
158 
159 	local_irq_save(flags);
160 
161 	/* Clear PCR high */
162 	scom970_write(SCOM_PCR, 0);
163 	/* Clear PCR low */
164        	scom970_write(SCOM_PCR, PCR_HILO_SELECT | 0);
165 	/* Set PCR low */
166 	scom970_write(SCOM_PCR, PCR_HILO_SELECT |
167 		      g5_pmode_data[speed_mode]);
168 
169 	/* Wait for completion */
170 	for (to = 0; to < 10; to++) {
171 		unsigned long psr = scom970_read(SCOM_PSR);
172 
173 		if ((psr & PSR_CMD_RECEIVED) == 0 &&
174 		    (((psr >> PSR_CUR_SPEED_SHIFT) ^
175 		      (g5_pmode_data[speed_mode] >> PCR_SPEED_SHIFT)) & 0x3)
176 		    == 0)
177 			break;
178 		if (psr & PSR_CMD_COMPLETED)
179 			break;
180 		udelay(100);
181 	}
182 
183 	local_irq_restore(flags);
184 
185 	/* If frequency is going down, last ramp the voltage */
186 	if (speed_mode > g5_pmode_cur)
187 		g5_switch_volt(speed_mode);
188 
189 	g5_pmode_cur = speed_mode;
190 	ppc_proc_freq = g5_cpu_freqs[speed_mode].frequency * 1000ul;
191 
192 	return 0;
193 }
194 
195 static int g5_scom_query_freq(void)
196 {
197 	unsigned long psr = scom970_read(SCOM_PSR);
198 	int i;
199 
200 	for (i = 0; i <= g5_pmode_max; i++)
201 		if ((((psr >> PSR_CUR_SPEED_SHIFT) ^
202 		      (g5_pmode_data[i] >> PCR_SPEED_SHIFT)) & 0x3) == 0)
203 			break;
204 	return i;
205 }
206 
207 /*
208  * Fake voltage switching for platforms with missing support
209  */
210 
211 static void g5_dummy_switch_volt(int speed_mode)
212 {
213 }
214 
215 #endif /* CONFIG_PMAC_SMU */
216 
217 /*
218  * Platform function based voltage switching for PowerMac7,2 & 7,3
219  */
220 
221 static struct pmf_function *pfunc_cpu0_volt_high;
222 static struct pmf_function *pfunc_cpu0_volt_low;
223 static struct pmf_function *pfunc_cpu1_volt_high;
224 static struct pmf_function *pfunc_cpu1_volt_low;
225 
226 static void g5_pfunc_switch_volt(int speed_mode)
227 {
228 	if (speed_mode == CPUFREQ_HIGH) {
229 		if (pfunc_cpu0_volt_high)
230 			pmf_call_one(pfunc_cpu0_volt_high, NULL);
231 		if (pfunc_cpu1_volt_high)
232 			pmf_call_one(pfunc_cpu1_volt_high, NULL);
233 	} else {
234 		if (pfunc_cpu0_volt_low)
235 			pmf_call_one(pfunc_cpu0_volt_low, NULL);
236 		if (pfunc_cpu1_volt_low)
237 			pmf_call_one(pfunc_cpu1_volt_low, NULL);
238 	}
239 	usleep_range(10000, 10000); /* should be faster , to fix */
240 }
241 
242 /*
243  * Platform function based frequency switching for PowerMac7,2 & 7,3
244  */
245 
246 static struct pmf_function *pfunc_cpu_setfreq_high;
247 static struct pmf_function *pfunc_cpu_setfreq_low;
248 static struct pmf_function *pfunc_cpu_getfreq;
249 static struct pmf_function *pfunc_slewing_done;
250 
251 static int g5_pfunc_switch_freq(int speed_mode)
252 {
253 	struct pmf_args args;
254 	u32 done = 0;
255 	unsigned long timeout;
256 	int rc;
257 
258 	DBG("g5_pfunc_switch_freq(%d)\n", speed_mode);
259 
260 	/* If frequency is going up, first ramp up the voltage */
261 	if (speed_mode < g5_pmode_cur)
262 		g5_switch_volt(speed_mode);
263 
264 	/* Do it */
265 	if (speed_mode == CPUFREQ_HIGH)
266 		rc = pmf_call_one(pfunc_cpu_setfreq_high, NULL);
267 	else
268 		rc = pmf_call_one(pfunc_cpu_setfreq_low, NULL);
269 
270 	if (rc)
271 		pr_warn("pfunc switch error %d\n", rc);
272 
273 	/* It's an irq GPIO so we should be able to just block here,
274 	 * I'll do that later after I've properly tested the IRQ code for
275 	 * platform functions
276 	 */
277 	timeout = jiffies + HZ/10;
278 	while(!time_after(jiffies, timeout)) {
279 		args.count = 1;
280 		args.u[0].p = &done;
281 		pmf_call_one(pfunc_slewing_done, &args);
282 		if (done)
283 			break;
284 		usleep_range(500, 500);
285 	}
286 	if (done == 0)
287 		pr_warn("Timeout in clock slewing !\n");
288 
289 	/* If frequency is going down, last ramp the voltage */
290 	if (speed_mode > g5_pmode_cur)
291 		g5_switch_volt(speed_mode);
292 
293 	g5_pmode_cur = speed_mode;
294 	ppc_proc_freq = g5_cpu_freqs[speed_mode].frequency * 1000ul;
295 
296 	return 0;
297 }
298 
299 static int g5_pfunc_query_freq(void)
300 {
301 	struct pmf_args args;
302 	u32 val = 0;
303 
304 	args.count = 1;
305 	args.u[0].p = &val;
306 	pmf_call_one(pfunc_cpu_getfreq, &args);
307 	return val ? CPUFREQ_HIGH : CPUFREQ_LOW;
308 }
309 
310 
311 /*
312  * Common interface to the cpufreq core
313  */
314 
315 static int g5_cpufreq_target(struct cpufreq_policy *policy, unsigned int index)
316 {
317 	return g5_switch_freq(index);
318 }
319 
320 static unsigned int g5_cpufreq_get_speed(unsigned int cpu)
321 {
322 	return g5_cpu_freqs[g5_pmode_cur].frequency;
323 }
324 
325 static int g5_cpufreq_cpu_init(struct cpufreq_policy *policy)
326 {
327 	return cpufreq_generic_init(policy, g5_cpu_freqs, transition_latency);
328 }
329 
330 static struct cpufreq_driver g5_cpufreq_driver = {
331 	.name		= "powermac",
332 	.flags		= CPUFREQ_CONST_LOOPS,
333 	.init		= g5_cpufreq_cpu_init,
334 	.verify		= cpufreq_generic_frequency_table_verify,
335 	.target_index	= g5_cpufreq_target,
336 	.get		= g5_cpufreq_get_speed,
337 	.attr 		= cpufreq_generic_attr,
338 };
339 
340 
341 #ifdef CONFIG_PMAC_SMU
342 
343 static int __init g5_neo2_cpufreq_init(struct device_node *cpunode)
344 {
345 	unsigned int psize, ssize;
346 	unsigned long max_freq;
347 	char *freq_method, *volt_method;
348 	const u32 *valp;
349 	u32 pvr_hi;
350 	int use_volts_vdnap = 0;
351 	int use_volts_smu = 0;
352 	int rc = -ENODEV;
353 
354 	/* Check supported platforms */
355 	if (of_machine_is_compatible("PowerMac8,1") ||
356 	    of_machine_is_compatible("PowerMac8,2") ||
357 	    of_machine_is_compatible("PowerMac9,1") ||
358 	    of_machine_is_compatible("PowerMac12,1"))
359 		use_volts_smu = 1;
360 	else if (of_machine_is_compatible("PowerMac11,2"))
361 		use_volts_vdnap = 1;
362 	else
363 		return -ENODEV;
364 
365 	/* Check 970FX for now */
366 	valp = of_get_property(cpunode, "cpu-version", NULL);
367 	if (!valp) {
368 		DBG("No cpu-version property !\n");
369 		goto bail_noprops;
370 	}
371 	pvr_hi = (*valp) >> 16;
372 	if (pvr_hi != 0x3c && pvr_hi != 0x44) {
373 		pr_err("Unsupported CPU version\n");
374 		goto bail_noprops;
375 	}
376 
377 	/* Look for the powertune data in the device-tree */
378 	g5_pmode_data = of_get_property(cpunode, "power-mode-data",&psize);
379 	if (!g5_pmode_data) {
380 		DBG("No power-mode-data !\n");
381 		goto bail_noprops;
382 	}
383 	g5_pmode_max = psize / sizeof(u32) - 1;
384 
385 	if (use_volts_smu) {
386 		const struct smu_sdbp_header *shdr;
387 
388 		/* Look for the FVT table */
389 		shdr = smu_get_sdb_partition(SMU_SDB_FVT_ID, NULL);
390 		if (!shdr)
391 			goto bail_noprops;
392 		g5_fvt_table = (struct smu_sdbp_fvt *)&shdr[1];
393 		ssize = (shdr->len * sizeof(u32)) - sizeof(*shdr);
394 		g5_fvt_count = ssize / sizeof(*g5_fvt_table);
395 		g5_fvt_cur = 0;
396 
397 		/* Sanity checking */
398 		if (g5_fvt_count < 1 || g5_pmode_max < 1)
399 			goto bail_noprops;
400 
401 		g5_switch_volt = g5_smu_switch_volt;
402 		volt_method = "SMU";
403 	} else if (use_volts_vdnap) {
404 		struct device_node *root;
405 
406 		root = of_find_node_by_path("/");
407 		if (root == NULL) {
408 			pr_err("Can't find root of device tree\n");
409 			goto bail_noprops;
410 		}
411 		pfunc_set_vdnap0 = pmf_find_function(root, "set-vdnap0");
412 		pfunc_vdnap0_complete =
413 			pmf_find_function(root, "slewing-done");
414 		if (pfunc_set_vdnap0 == NULL ||
415 		    pfunc_vdnap0_complete == NULL) {
416 			pr_err("Can't find required 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 	pr_info("Registering G5 CPU frequency driver\n");
457 	pr_info("Frequency method: %s, Voltage method: %s\n",
458 		freq_method, volt_method);
459 	pr_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 		pr_err("Can't find cpuid EEPROM !\n");
497 		rc = -ENODEV;
498 		goto bail;
499 	}
500 
501 	/* Lookup the i2c hwclock */
502 	for_each_node_by_name(hwclock, "i2c-hwclock") {
503 		const char *loc = of_get_property(hwclock,
504 				"hwctrl-location", NULL);
505 		if (loc == NULL)
506 			continue;
507 		if (strcmp(loc, "CPU CLOCK"))
508 			continue;
509 		if (!of_get_property(hwclock, "platform-get-frequency", NULL))
510 			continue;
511 		break;
512 	}
513 	if (hwclock == NULL) {
514 		pr_err("Can't find i2c clock chip !\n");
515 		rc = -ENODEV;
516 		goto bail;
517 	}
518 
519 	DBG("cpufreq: i2c clock chip found: %s\n", hwclock->full_name);
520 
521 	/* Now get all the platform functions */
522 	pfunc_cpu_getfreq =
523 		pmf_find_function(hwclock, "get-frequency");
524 	pfunc_cpu_setfreq_high =
525 		pmf_find_function(hwclock, "set-frequency-high");
526 	pfunc_cpu_setfreq_low =
527 		pmf_find_function(hwclock, "set-frequency-low");
528 	pfunc_slewing_done =
529 		pmf_find_function(hwclock, "slewing-done");
530 	pfunc_cpu0_volt_high =
531 		pmf_find_function(hwclock, "set-voltage-high-0");
532 	pfunc_cpu0_volt_low =
533 		pmf_find_function(hwclock, "set-voltage-low-0");
534 	pfunc_cpu1_volt_high =
535 		pmf_find_function(hwclock, "set-voltage-high-1");
536 	pfunc_cpu1_volt_low =
537 		pmf_find_function(hwclock, "set-voltage-low-1");
538 
539 	/* Check we have minimum requirements */
540 	if (pfunc_cpu_getfreq == NULL || pfunc_cpu_setfreq_high == NULL ||
541 	    pfunc_cpu_setfreq_low == NULL || pfunc_slewing_done == NULL) {
542 		pr_err("Can't find platform functions !\n");
543 		rc = -ENODEV;
544 		goto bail;
545 	}
546 
547 	/* Check that we have complete sets */
548 	if (pfunc_cpu0_volt_high == NULL || pfunc_cpu0_volt_low == NULL) {
549 		pmf_put_function(pfunc_cpu0_volt_high);
550 		pmf_put_function(pfunc_cpu0_volt_low);
551 		pfunc_cpu0_volt_high = pfunc_cpu0_volt_low = NULL;
552 		has_volt = 0;
553 	}
554 	if (!has_volt ||
555 	    pfunc_cpu1_volt_high == NULL || pfunc_cpu1_volt_low == NULL) {
556 		pmf_put_function(pfunc_cpu1_volt_high);
557 		pmf_put_function(pfunc_cpu1_volt_low);
558 		pfunc_cpu1_volt_high = pfunc_cpu1_volt_low = NULL;
559 	}
560 
561 	/* Note: The device tree also contains a "platform-set-values"
562 	 * function for which I haven't quite figured out the usage. It
563 	 * might have to be called on init and/or wakeup, I'm not too sure
564 	 * but things seem to work fine without it so far ...
565 	 */
566 
567 	/* Get max frequency from device-tree */
568 	valp = of_get_property(cpunode, "clock-frequency", NULL);
569 	if (!valp) {
570 		pr_err("Can't find CPU frequency !\n");
571 		rc = -ENODEV;
572 		goto bail;
573 	}
574 
575 	max_freq = (*valp)/1000;
576 
577 	/* Now calculate reduced frequency by using the cpuid input freq
578 	 * ratio. This requires 64 bits math unless we are willing to lose
579 	 * some precision
580 	 */
581 	ih = *((u32 *)(eeprom + 0x10));
582 	il = *((u32 *)(eeprom + 0x20));
583 
584 	/* Check for machines with no useful settings */
585 	if (il == ih) {
586 		pr_warn("No low frequency mode available on this model !\n");
587 		rc = -ENODEV;
588 		goto bail;
589 	}
590 
591 	min_freq = 0;
592 	if (ih != 0 && il != 0)
593 		min_freq = (max_freq * il) / ih;
594 
595 	/* Sanity check */
596 	if (min_freq >= max_freq || min_freq < 1000) {
597 		pr_err("Can't calculate low frequency !\n");
598 		rc = -ENXIO;
599 		goto bail;
600 	}
601 	g5_cpu_freqs[0].frequency = max_freq;
602 	g5_cpu_freqs[1].frequency = min_freq;
603 
604 	/* Based on a measurement on Xserve G5, rounded up. */
605 	transition_latency = 10 * NSEC_PER_MSEC;
606 
607 	/* Set callbacks */
608 	g5_switch_volt = g5_pfunc_switch_volt;
609 	g5_switch_freq = g5_pfunc_switch_freq;
610 	g5_query_freq = g5_pfunc_query_freq;
611 
612 	/* Force apply current frequency to make sure everything is in
613 	 * sync (voltage is right for example). Firmware may leave us with
614 	 * a strange setting ...
615 	 */
616 	g5_switch_volt(CPUFREQ_HIGH);
617 	msleep(10);
618 	g5_pmode_cur = -1;
619 	g5_switch_freq(g5_query_freq());
620 
621 	pr_info("Registering G5 CPU frequency driver\n");
622 	pr_info("Frequency method: i2c/pfunc, Voltage method: %s\n",
623 		has_volt ? "i2c/pfunc" : "none");
624 	pr_info("Low: %d Mhz, High: %d Mhz, Cur: %d MHz\n",
625 		g5_cpu_freqs[1].frequency/1000,
626 		g5_cpu_freqs[0].frequency/1000,
627 		g5_cpu_freqs[g5_pmode_cur].frequency/1000);
628 
629 	rc = cpufreq_register_driver(&g5_cpufreq_driver);
630  bail:
631 	if (rc != 0) {
632 		pmf_put_function(pfunc_cpu_getfreq);
633 		pmf_put_function(pfunc_cpu_setfreq_high);
634 		pmf_put_function(pfunc_cpu_setfreq_low);
635 		pmf_put_function(pfunc_slewing_done);
636 		pmf_put_function(pfunc_cpu0_volt_high);
637 		pmf_put_function(pfunc_cpu0_volt_low);
638 		pmf_put_function(pfunc_cpu1_volt_high);
639 		pmf_put_function(pfunc_cpu1_volt_low);
640 	}
641 	of_node_put(hwclock);
642 	of_node_put(cpuid);
643 	of_node_put(cpunode);
644 
645 	return rc;
646 }
647 
648 static int __init g5_cpufreq_init(void)
649 {
650 	struct device_node *cpunode;
651 	int rc = 0;
652 
653 	/* Get first CPU node */
654 	cpunode = of_cpu_device_node_get(0);
655 	if (cpunode == NULL) {
656 		pr_err("Can't find any CPU node\n");
657 		return -ENODEV;
658 	}
659 
660 	if (of_machine_is_compatible("PowerMac7,2") ||
661 	    of_machine_is_compatible("PowerMac7,3") ||
662 	    of_machine_is_compatible("RackMac3,1"))
663 		rc = g5_pm72_cpufreq_init(cpunode);
664 #ifdef CONFIG_PMAC_SMU
665 	else
666 		rc = g5_neo2_cpufreq_init(cpunode);
667 #endif /* CONFIG_PMAC_SMU */
668 
669 	return rc;
670 }
671 
672 module_init(g5_cpufreq_init);
673 
674 
675 MODULE_LICENSE("GPL");
676