xref: /linux/drivers/cpufreq/pmac64-cpufreq.c (revision a0efa2f362a69e47b9d8b48f770ef3a0249a7911)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  *  Copyright (C) 2002 - 2005 Benjamin Herrenschmidt <benh@kernel.crashing.org>
4  *  and                       Markus Demleitner <msdemlei@cl.uni-heidelberg.de>
5  *
6  * This driver adds basic cpufreq support for SMU & 970FX based G5 Macs,
7  * that is iMac G5 and latest single CPU desktop.
8  */
9 
10 #undef DEBUG
11 
12 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
13 
14 #include <linux/module.h>
15 #include <linux/types.h>
16 #include <linux/errno.h>
17 #include <linux/kernel.h>
18 #include <linux/delay.h>
19 #include <linux/sched.h>
20 #include <linux/cpufreq.h>
21 #include <linux/init.h>
22 #include <linux/completion.h>
23 #include <linux/mutex.h>
24 #include <linux/of.h>
25 
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 	{0, CPUFREQ_HIGH,	0},
68 	{0, CPUFREQ_LOW,	0},
69 	{0, 0,			CPUFREQ_TABLE_END},
70 };
71 
72 /* Power mode data is an array of the 32 bits PCR values to use for
73  * the various frequencies, retrieved from the device-tree
74  */
75 static int g5_pmode_cur;
76 
77 static void (*g5_switch_volt)(int speed_mode);
78 static int (*g5_switch_freq)(int speed_mode);
79 static int (*g5_query_freq)(void);
80 
81 static unsigned long transition_latency;
82 
83 #ifdef CONFIG_PMAC_SMU
84 
85 static const u32 *g5_pmode_data;
86 static int g5_pmode_max;
87 
88 static struct smu_sdbp_fvt *g5_fvt_table;	/* table of op. points */
89 static int g5_fvt_count;			/* number of op. points */
90 static int g5_fvt_cur;				/* current op. point */
91 
92 /*
93  * SMU based voltage switching for Neo2 platforms
94  */
95 
96 static void g5_smu_switch_volt(int speed_mode)
97 {
98 	struct smu_simple_cmd	cmd;
99 
100 	DECLARE_COMPLETION_ONSTACK(comp);
101 	smu_queue_simple(&cmd, SMU_CMD_POWER_COMMAND, 8, smu_done_complete,
102 			 &comp, 'V', 'S', 'L', 'E', 'W',
103 			 0xff, g5_fvt_cur+1, speed_mode);
104 	wait_for_completion(&comp);
105 }
106 
107 /*
108  * Platform function based voltage/vdnap switching for Neo2
109  */
110 
111 static struct pmf_function *pfunc_set_vdnap0;
112 static struct pmf_function *pfunc_vdnap0_complete;
113 
114 static void g5_vdnap_switch_volt(int speed_mode)
115 {
116 	struct pmf_args args;
117 	u32 slew, done = 0;
118 	unsigned long timeout;
119 
120 	slew = (speed_mode == CPUFREQ_LOW) ? 1 : 0;
121 	args.count = 1;
122 	args.u[0].p = &slew;
123 
124 	pmf_call_one(pfunc_set_vdnap0, &args);
125 
126 	/* It's an irq GPIO so we should be able to just block here,
127 	 * I'll do that later after I've properly tested the IRQ code for
128 	 * platform functions
129 	 */
130 	timeout = jiffies + HZ/10;
131 	while(!time_after(jiffies, timeout)) {
132 		args.count = 1;
133 		args.u[0].p = &done;
134 		pmf_call_one(pfunc_vdnap0_complete, &args);
135 		if (done)
136 			break;
137 		usleep_range(1000, 1000);
138 	}
139 	if (done == 0)
140 		pr_warn("Timeout in clock slewing !\n");
141 }
142 
143 
144 /*
145  * SCOM based frequency switching for 970FX rev3
146  */
147 static int g5_scom_switch_freq(int speed_mode)
148 {
149 	unsigned long flags;
150 	int to;
151 
152 	/* If frequency is going up, first ramp up the voltage */
153 	if (speed_mode < g5_pmode_cur)
154 		g5_switch_volt(speed_mode);
155 
156 	local_irq_save(flags);
157 
158 	/* Clear PCR high */
159 	scom970_write(SCOM_PCR, 0);
160 	/* Clear PCR low */
161        	scom970_write(SCOM_PCR, PCR_HILO_SELECT | 0);
162 	/* Set PCR low */
163 	scom970_write(SCOM_PCR, PCR_HILO_SELECT |
164 		      g5_pmode_data[speed_mode]);
165 
166 	/* Wait for completion */
167 	for (to = 0; to < 10; to++) {
168 		unsigned long psr = scom970_read(SCOM_PSR);
169 
170 		if ((psr & PSR_CMD_RECEIVED) == 0 &&
171 		    (((psr >> PSR_CUR_SPEED_SHIFT) ^
172 		      (g5_pmode_data[speed_mode] >> PCR_SPEED_SHIFT)) & 0x3)
173 		    == 0)
174 			break;
175 		if (psr & PSR_CMD_COMPLETED)
176 			break;
177 		udelay(100);
178 	}
179 
180 	local_irq_restore(flags);
181 
182 	/* If frequency is going down, last ramp the voltage */
183 	if (speed_mode > g5_pmode_cur)
184 		g5_switch_volt(speed_mode);
185 
186 	g5_pmode_cur = speed_mode;
187 	ppc_proc_freq = g5_cpu_freqs[speed_mode].frequency * 1000ul;
188 
189 	return 0;
190 }
191 
192 static int g5_scom_query_freq(void)
193 {
194 	unsigned long psr = scom970_read(SCOM_PSR);
195 	int i;
196 
197 	for (i = 0; i <= g5_pmode_max; i++)
198 		if ((((psr >> PSR_CUR_SPEED_SHIFT) ^
199 		      (g5_pmode_data[i] >> PCR_SPEED_SHIFT)) & 0x3) == 0)
200 			break;
201 	return i;
202 }
203 
204 /*
205  * Fake voltage switching for platforms with missing support
206  */
207 
208 static void g5_dummy_switch_volt(int speed_mode)
209 {
210 }
211 
212 #endif /* CONFIG_PMAC_SMU */
213 
214 /*
215  * Platform function based voltage switching for PowerMac7,2 & 7,3
216  */
217 
218 static struct pmf_function *pfunc_cpu0_volt_high;
219 static struct pmf_function *pfunc_cpu0_volt_low;
220 static struct pmf_function *pfunc_cpu1_volt_high;
221 static struct pmf_function *pfunc_cpu1_volt_low;
222 
223 static void g5_pfunc_switch_volt(int speed_mode)
224 {
225 	if (speed_mode == CPUFREQ_HIGH) {
226 		if (pfunc_cpu0_volt_high)
227 			pmf_call_one(pfunc_cpu0_volt_high, NULL);
228 		if (pfunc_cpu1_volt_high)
229 			pmf_call_one(pfunc_cpu1_volt_high, NULL);
230 	} else {
231 		if (pfunc_cpu0_volt_low)
232 			pmf_call_one(pfunc_cpu0_volt_low, NULL);
233 		if (pfunc_cpu1_volt_low)
234 			pmf_call_one(pfunc_cpu1_volt_low, NULL);
235 	}
236 	usleep_range(10000, 10000); /* should be faster , to fix */
237 }
238 
239 /*
240  * Platform function based frequency switching for PowerMac7,2 & 7,3
241  */
242 
243 static struct pmf_function *pfunc_cpu_setfreq_high;
244 static struct pmf_function *pfunc_cpu_setfreq_low;
245 static struct pmf_function *pfunc_cpu_getfreq;
246 static struct pmf_function *pfunc_slewing_done;
247 
248 static int g5_pfunc_switch_freq(int speed_mode)
249 {
250 	struct pmf_args args;
251 	u32 done = 0;
252 	unsigned long timeout;
253 	int rc;
254 
255 	DBG("g5_pfunc_switch_freq(%d)\n", speed_mode);
256 
257 	/* If frequency is going up, first ramp up the voltage */
258 	if (speed_mode < g5_pmode_cur)
259 		g5_switch_volt(speed_mode);
260 
261 	/* Do it */
262 	if (speed_mode == CPUFREQ_HIGH)
263 		rc = pmf_call_one(pfunc_cpu_setfreq_high, NULL);
264 	else
265 		rc = pmf_call_one(pfunc_cpu_setfreq_low, NULL);
266 
267 	if (rc)
268 		pr_warn("pfunc switch error %d\n", rc);
269 
270 	/* It's an irq GPIO so we should be able to just block here,
271 	 * I'll do that later after I've properly tested the IRQ code for
272 	 * platform functions
273 	 */
274 	timeout = jiffies + HZ/10;
275 	while(!time_after(jiffies, timeout)) {
276 		args.count = 1;
277 		args.u[0].p = &done;
278 		pmf_call_one(pfunc_slewing_done, &args);
279 		if (done)
280 			break;
281 		usleep_range(500, 500);
282 	}
283 	if (done == 0)
284 		pr_warn("Timeout in clock slewing !\n");
285 
286 	/* If frequency is going down, last ramp the voltage */
287 	if (speed_mode > g5_pmode_cur)
288 		g5_switch_volt(speed_mode);
289 
290 	g5_pmode_cur = speed_mode;
291 	ppc_proc_freq = g5_cpu_freqs[speed_mode].frequency * 1000ul;
292 
293 	return 0;
294 }
295 
296 static int g5_pfunc_query_freq(void)
297 {
298 	struct pmf_args args;
299 	u32 val = 0;
300 
301 	args.count = 1;
302 	args.u[0].p = &val;
303 	pmf_call_one(pfunc_cpu_getfreq, &args);
304 	return val ? CPUFREQ_HIGH : CPUFREQ_LOW;
305 }
306 
307 
308 /*
309  * Common interface to the cpufreq core
310  */
311 
312 static int g5_cpufreq_target(struct cpufreq_policy *policy, unsigned int index)
313 {
314 	return g5_switch_freq(index);
315 }
316 
317 static unsigned int g5_cpufreq_get_speed(unsigned int cpu)
318 {
319 	return g5_cpu_freqs[g5_pmode_cur].frequency;
320 }
321 
322 static int g5_cpufreq_cpu_init(struct cpufreq_policy *policy)
323 {
324 	cpufreq_generic_init(policy, g5_cpu_freqs, transition_latency);
325 	return 0;
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 		pr_err("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 			pr_err("Can't find root of device tree\n");
407 			goto bail_noprops;
408 		}
409 		pfunc_set_vdnap0 = pmf_find_function(root, "set-vdnap0");
410 		pfunc_vdnap0_complete =
411 			pmf_find_function(root, "slewing-done");
412 		of_node_put(root);
413 		if (pfunc_set_vdnap0 == NULL ||
414 		    pfunc_vdnap0_complete == NULL) {
415 			pr_err("Can't find required platform function\n");
416 			goto bail_noprops;
417 		}
418 
419 		g5_switch_volt = g5_vdnap_switch_volt;
420 		volt_method = "GPIO";
421 	} else {
422 		g5_switch_volt = g5_dummy_switch_volt;
423 		volt_method = "none";
424 	}
425 
426 	/*
427 	 * From what I see, clock-frequency is always the maximal frequency.
428 	 * The current driver can not slew sysclk yet, so we really only deal
429 	 * with powertune steps for now. We also only implement full freq and
430 	 * half freq in this version. So far, I haven't yet seen a machine
431 	 * supporting anything else.
432 	 */
433 	valp = of_get_property(cpunode, "clock-frequency", NULL);
434 	if (!valp)
435 		return -ENODEV;
436 	max_freq = (*valp)/1000;
437 	g5_cpu_freqs[0].frequency = max_freq;
438 	g5_cpu_freqs[1].frequency = max_freq/2;
439 
440 	/* Set callbacks */
441 	transition_latency = 12000;
442 	g5_switch_freq = g5_scom_switch_freq;
443 	g5_query_freq = g5_scom_query_freq;
444 	freq_method = "SCOM";
445 
446 	/* Force apply current frequency to make sure everything is in
447 	 * sync (voltage is right for example). Firmware may leave us with
448 	 * a strange setting ...
449 	 */
450 	g5_switch_volt(CPUFREQ_HIGH);
451 	msleep(10);
452 	g5_pmode_cur = -1;
453 	g5_switch_freq(g5_query_freq());
454 
455 	pr_info("Registering G5 CPU frequency driver\n");
456 	pr_info("Frequency method: %s, Voltage method: %s\n",
457 		freq_method, volt_method);
458 	pr_info("Low: %d Mhz, High: %d Mhz, Cur: %d MHz\n",
459 		g5_cpu_freqs[1].frequency/1000,
460 		g5_cpu_freqs[0].frequency/1000,
461 		g5_cpu_freqs[g5_pmode_cur].frequency/1000);
462 
463 	rc = cpufreq_register_driver(&g5_cpufreq_driver);
464 
465 	/* We keep the CPU node on hold... hopefully, Apple G5 don't have
466 	 * hotplug CPU with a dynamic device-tree ...
467 	 */
468 	return rc;
469 
470  bail_noprops:
471 	of_node_put(cpunode);
472 
473 	return rc;
474 }
475 
476 #endif /* CONFIG_PMAC_SMU */
477 
478 
479 static int __init g5_pm72_cpufreq_init(struct device_node *cpunode)
480 {
481 	struct device_node *cpuid = NULL, *hwclock = NULL;
482 	const u8 *eeprom = NULL;
483 	const u32 *valp;
484 	u64 max_freq, min_freq, ih, il;
485 	int has_volt = 1, rc = 0;
486 
487 	DBG("cpufreq: Initializing for PowerMac7,2, PowerMac7,3 and"
488 	    " RackMac3,1...\n");
489 
490 	/* Lookup the cpuid eeprom node */
491         cpuid = of_find_node_by_path("/u3@0,f8000000/i2c@f8001000/cpuid@a0");
492 	if (cpuid != NULL)
493 		eeprom = of_get_property(cpuid, "cpuid", NULL);
494 	if (eeprom == NULL) {
495 		pr_err("Can't find cpuid EEPROM !\n");
496 		rc = -ENODEV;
497 		goto bail;
498 	}
499 
500 	/* Lookup the i2c hwclock */
501 	for_each_node_by_name(hwclock, "i2c-hwclock") {
502 		const char *loc = of_get_property(hwclock,
503 				"hwctrl-location", NULL);
504 		if (loc == NULL)
505 			continue;
506 		if (strcmp(loc, "CPU CLOCK"))
507 			continue;
508 		if (!of_property_present(hwclock, "platform-get-frequency"))
509 			continue;
510 		break;
511 	}
512 	if (hwclock == NULL) {
513 		pr_err("Can't find i2c clock chip !\n");
514 		rc = -ENODEV;
515 		goto bail;
516 	}
517 
518 	DBG("cpufreq: i2c clock chip found: %pOF\n", hwclock);
519 
520 	/* Now get all the platform functions */
521 	pfunc_cpu_getfreq =
522 		pmf_find_function(hwclock, "get-frequency");
523 	pfunc_cpu_setfreq_high =
524 		pmf_find_function(hwclock, "set-frequency-high");
525 	pfunc_cpu_setfreq_low =
526 		pmf_find_function(hwclock, "set-frequency-low");
527 	pfunc_slewing_done =
528 		pmf_find_function(hwclock, "slewing-done");
529 	pfunc_cpu0_volt_high =
530 		pmf_find_function(hwclock, "set-voltage-high-0");
531 	pfunc_cpu0_volt_low =
532 		pmf_find_function(hwclock, "set-voltage-low-0");
533 	pfunc_cpu1_volt_high =
534 		pmf_find_function(hwclock, "set-voltage-high-1");
535 	pfunc_cpu1_volt_low =
536 		pmf_find_function(hwclock, "set-voltage-low-1");
537 
538 	/* Check we have minimum requirements */
539 	if (pfunc_cpu_getfreq == NULL || pfunc_cpu_setfreq_high == NULL ||
540 	    pfunc_cpu_setfreq_low == NULL || pfunc_slewing_done == NULL) {
541 		pr_err("Can't find platform functions !\n");
542 		rc = -ENODEV;
543 		goto bail;
544 	}
545 
546 	/* Check that we have complete sets */
547 	if (pfunc_cpu0_volt_high == NULL || pfunc_cpu0_volt_low == NULL) {
548 		pmf_put_function(pfunc_cpu0_volt_high);
549 		pmf_put_function(pfunc_cpu0_volt_low);
550 		pfunc_cpu0_volt_high = pfunc_cpu0_volt_low = NULL;
551 		has_volt = 0;
552 	}
553 	if (!has_volt ||
554 	    pfunc_cpu1_volt_high == NULL || pfunc_cpu1_volt_low == NULL) {
555 		pmf_put_function(pfunc_cpu1_volt_high);
556 		pmf_put_function(pfunc_cpu1_volt_low);
557 		pfunc_cpu1_volt_high = pfunc_cpu1_volt_low = NULL;
558 	}
559 
560 	/* Note: The device tree also contains a "platform-set-values"
561 	 * function for which I haven't quite figured out the usage. It
562 	 * might have to be called on init and/or wakeup, I'm not too sure
563 	 * but things seem to work fine without it so far ...
564 	 */
565 
566 	/* Get max frequency from device-tree */
567 	valp = of_get_property(cpunode, "clock-frequency", NULL);
568 	if (!valp) {
569 		pr_err("Can't find CPU frequency !\n");
570 		rc = -ENODEV;
571 		goto bail;
572 	}
573 
574 	max_freq = (*valp)/1000;
575 
576 	/* Now calculate reduced frequency by using the cpuid input freq
577 	 * ratio. This requires 64 bits math unless we are willing to lose
578 	 * some precision
579 	 */
580 	ih = *((u32 *)(eeprom + 0x10));
581 	il = *((u32 *)(eeprom + 0x20));
582 
583 	/* Check for machines with no useful settings */
584 	if (il == ih) {
585 		pr_warn("No low frequency mode available on this model !\n");
586 		rc = -ENODEV;
587 		goto bail;
588 	}
589 
590 	min_freq = 0;
591 	if (ih != 0 && il != 0)
592 		min_freq = (max_freq * il) / ih;
593 
594 	/* Sanity check */
595 	if (min_freq >= max_freq || min_freq < 1000) {
596 		pr_err("Can't calculate low frequency !\n");
597 		rc = -ENXIO;
598 		goto bail;
599 	}
600 	g5_cpu_freqs[0].frequency = max_freq;
601 	g5_cpu_freqs[1].frequency = min_freq;
602 
603 	/* Based on a measurement on Xserve G5, rounded up. */
604 	transition_latency = 10 * NSEC_PER_MSEC;
605 
606 	/* Set callbacks */
607 	g5_switch_volt = g5_pfunc_switch_volt;
608 	g5_switch_freq = g5_pfunc_switch_freq;
609 	g5_query_freq = g5_pfunc_query_freq;
610 
611 	/* Force apply current frequency to make sure everything is in
612 	 * sync (voltage is right for example). Firmware may leave us with
613 	 * a strange setting ...
614 	 */
615 	g5_switch_volt(CPUFREQ_HIGH);
616 	msleep(10);
617 	g5_pmode_cur = -1;
618 	g5_switch_freq(g5_query_freq());
619 
620 	pr_info("Registering G5 CPU frequency driver\n");
621 	pr_info("Frequency method: i2c/pfunc, Voltage method: %s\n",
622 		has_volt ? "i2c/pfunc" : "none");
623 	pr_info("Low: %d Mhz, High: %d Mhz, Cur: %d MHz\n",
624 		g5_cpu_freqs[1].frequency/1000,
625 		g5_cpu_freqs[0].frequency/1000,
626 		g5_cpu_freqs[g5_pmode_cur].frequency/1000);
627 
628 	rc = cpufreq_register_driver(&g5_cpufreq_driver);
629  bail:
630 	if (rc != 0) {
631 		pmf_put_function(pfunc_cpu_getfreq);
632 		pmf_put_function(pfunc_cpu_setfreq_high);
633 		pmf_put_function(pfunc_cpu_setfreq_low);
634 		pmf_put_function(pfunc_slewing_done);
635 		pmf_put_function(pfunc_cpu0_volt_high);
636 		pmf_put_function(pfunc_cpu0_volt_low);
637 		pmf_put_function(pfunc_cpu1_volt_high);
638 		pmf_put_function(pfunc_cpu1_volt_low);
639 	}
640 	of_node_put(hwclock);
641 	of_node_put(cpuid);
642 	of_node_put(cpunode);
643 
644 	return rc;
645 }
646 
647 static int __init g5_cpufreq_init(void)
648 {
649 	struct device_node *cpunode;
650 	int rc = 0;
651 
652 	/* Get first CPU node */
653 	cpunode = of_cpu_device_node_get(0);
654 	if (cpunode == NULL) {
655 		pr_err("Can't find any CPU node\n");
656 		return -ENODEV;
657 	}
658 
659 	if (of_machine_is_compatible("PowerMac7,2") ||
660 	    of_machine_is_compatible("PowerMac7,3") ||
661 	    of_machine_is_compatible("RackMac3,1"))
662 		rc = g5_pm72_cpufreq_init(cpunode);
663 #ifdef CONFIG_PMAC_SMU
664 	else
665 		rc = g5_neo2_cpufreq_init(cpunode);
666 #endif /* CONFIG_PMAC_SMU */
667 
668 	return rc;
669 }
670 
671 module_init(g5_cpufreq_init);
672 
673 
674 MODULE_DESCRIPTION("cpufreq driver for SMU & 970FX based G5 Macs");
675 MODULE_LICENSE("GPL");
676