2 * Copyright (C) 2002 - 2005 Benjamin Herrenschmidt <benh@kernel.crashing.org>
3 * and Markus Demleitner <msdemlei@cl.uni-heidelberg.de>
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.
9 * This driver adds basic cpufreq support for SMU & 970FX based G5 Macs,
10 * that is iMac G5 and latest single CPU desktop.
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>
27 #include <asm/machdep.h>
29 #include <asm/sections.h>
30 #include <asm/cputable.h>
33 #include <asm/pmac_pfunc.h>
35 #define DBG(fmt...) pr_debug(fmt)
37 /* see 970FX user manual */
39 #define SCOM_PCR 0x0aa001 /* PCR scom addr */
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 */
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)
62 * The G5 only supports two frequencies (Quarter speed is not supported)
64 #define CPUFREQ_HIGH 0
67 static struct cpufreq_frequency_table g5_cpu_freqs[] = {
70 {0, CPUFREQ_TABLE_END},
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
76 static int g5_pmode_cur;
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);
82 static DEFINE_MUTEX(g5_switch_mutex);
84 static unsigned long transition_latency;
86 #ifdef CONFIG_PMAC_SMU
88 static const u32 *g5_pmode_data;
89 static int g5_pmode_max;
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 */
96 * SMU based voltage switching for Neo2 platforms
99 static void g5_smu_switch_volt(int speed_mode)
101 struct smu_simple_cmd cmd;
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);
111 * Platform function based voltage/vdnap switching for Neo2
114 static struct pmf_function *pfunc_set_vdnap0;
115 static struct pmf_function *pfunc_vdnap0_complete;
117 static void g5_vdnap_switch_volt(int speed_mode)
119 struct pmf_args args;
121 unsigned long timeout;
123 slew = (speed_mode == CPUFREQ_LOW) ? 1 : 0;
127 pmf_call_one(pfunc_set_vdnap0, &args);
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
133 timeout = jiffies + HZ/10;
134 while(!time_after(jiffies, timeout)) {
137 pmf_call_one(pfunc_vdnap0_complete, &args);
143 printk(KERN_WARNING "cpufreq: Timeout in clock slewing !\n");
148 * SCOM based frequency switching for 970FX rev3
150 static int g5_scom_switch_freq(int speed_mode)
155 /* If frequency is going up, first ramp up the voltage */
156 if (speed_mode < g5_pmode_cur)
157 g5_switch_volt(speed_mode);
159 local_irq_save(flags);
162 scom970_write(SCOM_PCR, 0);
164 scom970_write(SCOM_PCR, PCR_HILO_SELECT | 0);
166 scom970_write(SCOM_PCR, PCR_HILO_SELECT |
167 g5_pmode_data[speed_mode]);
169 /* Wait for completion */
170 for (to = 0; to < 10; to++) {
171 unsigned long psr = scom970_read(SCOM_PSR);
173 if ((psr & PSR_CMD_RECEIVED) == 0 &&
174 (((psr >> PSR_CUR_SPEED_SHIFT) ^
175 (g5_pmode_data[speed_mode] >> PCR_SPEED_SHIFT)) & 0x3)
178 if (psr & PSR_CMD_COMPLETED)
183 local_irq_restore(flags);
185 /* If frequency is going down, last ramp the voltage */
186 if (speed_mode > g5_pmode_cur)
187 g5_switch_volt(speed_mode);
189 g5_pmode_cur = speed_mode;
190 ppc_proc_freq = g5_cpu_freqs[speed_mode].frequency * 1000ul;
195 static int g5_scom_query_freq(void)
197 unsigned long psr = scom970_read(SCOM_PSR);
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)
208 * Fake voltage switching for platforms with missing support
211 static void g5_dummy_switch_volt(int speed_mode)
215 #endif /* CONFIG_PMAC_SMU */
218 * Platform function based voltage switching for PowerMac7,2 & 7,3
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;
226 static void g5_pfunc_switch_volt(int speed_mode)
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);
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);
239 msleep(10); /* should be faster , to fix */
243 * Platform function based frequency switching for PowerMac7,2 & 7,3
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;
251 static int g5_pfunc_switch_freq(int speed_mode)
253 struct pmf_args args;
255 unsigned long timeout;
258 DBG("g5_pfunc_switch_freq(%d)\n", speed_mode);
260 /* If frequency is going up, first ramp up the voltage */
261 if (speed_mode < g5_pmode_cur)
262 g5_switch_volt(speed_mode);
265 if (speed_mode == CPUFREQ_HIGH)
266 rc = pmf_call_one(pfunc_cpu_setfreq_high, NULL);
268 rc = pmf_call_one(pfunc_cpu_setfreq_low, NULL);
271 printk(KERN_WARNING "cpufreq: pfunc switch error %d\n", rc);
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
277 timeout = jiffies + HZ/10;
278 while(!time_after(jiffies, timeout)) {
281 pmf_call_one(pfunc_slewing_done, &args);
287 printk(KERN_WARNING "cpufreq: Timeout in clock slewing !\n");
289 /* If frequency is going down, last ramp the voltage */
290 if (speed_mode > g5_pmode_cur)
291 g5_switch_volt(speed_mode);
293 g5_pmode_cur = speed_mode;
294 ppc_proc_freq = g5_cpu_freqs[speed_mode].frequency * 1000ul;
299 static int g5_pfunc_query_freq(void)
301 struct pmf_args args;
306 pmf_call_one(pfunc_cpu_getfreq, &args);
307 return val ? CPUFREQ_HIGH : CPUFREQ_LOW;
312 * Common interface to the cpufreq core
315 static int g5_cpufreq_target(struct cpufreq_policy *policy,
316 unsigned int target_freq, unsigned int relation)
318 unsigned int newstate = 0;
319 struct cpufreq_freqs freqs;
322 if (cpufreq_frequency_table_target(policy, g5_cpu_freqs,
323 target_freq, relation, &newstate))
326 if (g5_pmode_cur == newstate)
329 mutex_lock(&g5_switch_mutex);
331 freqs.old = g5_cpu_freqs[g5_pmode_cur].frequency;
332 freqs.new = g5_cpu_freqs[newstate].frequency;
334 cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE);
335 rc = g5_switch_freq(newstate);
336 cpufreq_notify_transition(policy, &freqs, CPUFREQ_POSTCHANGE);
338 mutex_unlock(&g5_switch_mutex);
343 static unsigned int g5_cpufreq_get_speed(unsigned int cpu)
345 return g5_cpu_freqs[g5_pmode_cur].frequency;
348 static int g5_cpufreq_cpu_init(struct cpufreq_policy *policy)
350 return cpufreq_generic_init(policy, g5_cpu_freqs, transition_latency);
353 static struct cpufreq_driver g5_cpufreq_driver = {
355 .flags = CPUFREQ_CONST_LOOPS,
356 .init = g5_cpufreq_cpu_init,
357 .verify = cpufreq_generic_frequency_table_verify,
358 .target = g5_cpufreq_target,
359 .get = g5_cpufreq_get_speed,
360 .attr = cpufreq_generic_attr,
364 #ifdef CONFIG_PMAC_SMU
366 static int __init g5_neo2_cpufreq_init(struct device_node *cpunode)
368 unsigned int psize, ssize;
369 unsigned long max_freq;
370 char *freq_method, *volt_method;
373 int use_volts_vdnap = 0;
374 int use_volts_smu = 0;
377 /* Check supported platforms */
378 if (of_machine_is_compatible("PowerMac8,1") ||
379 of_machine_is_compatible("PowerMac8,2") ||
380 of_machine_is_compatible("PowerMac9,1"))
382 else if (of_machine_is_compatible("PowerMac11,2"))
387 /* Check 970FX for now */
388 valp = of_get_property(cpunode, "cpu-version", NULL);
390 DBG("No cpu-version property !\n");
393 pvr_hi = (*valp) >> 16;
394 if (pvr_hi != 0x3c && pvr_hi != 0x44) {
395 printk(KERN_ERR "cpufreq: Unsupported CPU version\n");
399 /* Look for the powertune data in the device-tree */
400 g5_pmode_data = of_get_property(cpunode, "power-mode-data",&psize);
401 if (!g5_pmode_data) {
402 DBG("No power-mode-data !\n");
405 g5_pmode_max = psize / sizeof(u32) - 1;
408 const struct smu_sdbp_header *shdr;
410 /* Look for the FVT table */
411 shdr = smu_get_sdb_partition(SMU_SDB_FVT_ID, NULL);
414 g5_fvt_table = (struct smu_sdbp_fvt *)&shdr[1];
415 ssize = (shdr->len * sizeof(u32)) - sizeof(*shdr);
416 g5_fvt_count = ssize / sizeof(*g5_fvt_table);
419 /* Sanity checking */
420 if (g5_fvt_count < 1 || g5_pmode_max < 1)
423 g5_switch_volt = g5_smu_switch_volt;
425 } else if (use_volts_vdnap) {
426 struct device_node *root;
428 root = of_find_node_by_path("/");
430 printk(KERN_ERR "cpufreq: Can't find root of "
434 pfunc_set_vdnap0 = pmf_find_function(root, "set-vdnap0");
435 pfunc_vdnap0_complete =
436 pmf_find_function(root, "slewing-done");
437 if (pfunc_set_vdnap0 == NULL ||
438 pfunc_vdnap0_complete == NULL) {
439 printk(KERN_ERR "cpufreq: Can't find required "
440 "platform function\n");
444 g5_switch_volt = g5_vdnap_switch_volt;
445 volt_method = "GPIO";
447 g5_switch_volt = g5_dummy_switch_volt;
448 volt_method = "none";
452 * From what I see, clock-frequency is always the maximal frequency.
453 * The current driver can not slew sysclk yet, so we really only deal
454 * with powertune steps for now. We also only implement full freq and
455 * half freq in this version. So far, I haven't yet seen a machine
456 * supporting anything else.
458 valp = of_get_property(cpunode, "clock-frequency", NULL);
461 max_freq = (*valp)/1000;
462 g5_cpu_freqs[0].frequency = max_freq;
463 g5_cpu_freqs[1].frequency = max_freq/2;
466 transition_latency = 12000;
467 g5_switch_freq = g5_scom_switch_freq;
468 g5_query_freq = g5_scom_query_freq;
469 freq_method = "SCOM";
471 /* Force apply current frequency to make sure everything is in
472 * sync (voltage is right for example). Firmware may leave us with
473 * a strange setting ...
475 g5_switch_volt(CPUFREQ_HIGH);
478 g5_switch_freq(g5_query_freq());
480 printk(KERN_INFO "Registering G5 CPU frequency driver\n");
481 printk(KERN_INFO "Frequency method: %s, Voltage method: %s\n",
482 freq_method, volt_method);
483 printk(KERN_INFO "Low: %d Mhz, High: %d Mhz, Cur: %d MHz\n",
484 g5_cpu_freqs[1].frequency/1000,
485 g5_cpu_freqs[0].frequency/1000,
486 g5_cpu_freqs[g5_pmode_cur].frequency/1000);
488 rc = cpufreq_register_driver(&g5_cpufreq_driver);
490 /* We keep the CPU node on hold... hopefully, Apple G5 don't have
491 * hotplug CPU with a dynamic device-tree ...
496 of_node_put(cpunode);
501 #endif /* CONFIG_PMAC_SMU */
504 static int __init g5_pm72_cpufreq_init(struct device_node *cpunode)
506 struct device_node *cpuid = NULL, *hwclock = NULL;
507 const u8 *eeprom = NULL;
509 u64 max_freq, min_freq, ih, il;
510 int has_volt = 1, rc = 0;
512 DBG("cpufreq: Initializing for PowerMac7,2, PowerMac7,3 and"
515 /* Lookup the cpuid eeprom node */
516 cpuid = of_find_node_by_path("/u3@0,f8000000/i2c@f8001000/cpuid@a0");
518 eeprom = of_get_property(cpuid, "cpuid", NULL);
519 if (eeprom == NULL) {
520 printk(KERN_ERR "cpufreq: Can't find cpuid EEPROM !\n");
525 /* Lookup the i2c hwclock */
527 (hwclock = of_find_node_by_name(hwclock, "i2c-hwclock")) != NULL;){
528 const char *loc = of_get_property(hwclock,
529 "hwctrl-location", NULL);
532 if (strcmp(loc, "CPU CLOCK"))
534 if (!of_get_property(hwclock, "platform-get-frequency", NULL))
538 if (hwclock == NULL) {
539 printk(KERN_ERR "cpufreq: Can't find i2c clock chip !\n");
544 DBG("cpufreq: i2c clock chip found: %s\n", hwclock->full_name);
546 /* Now get all the platform functions */
548 pmf_find_function(hwclock, "get-frequency");
549 pfunc_cpu_setfreq_high =
550 pmf_find_function(hwclock, "set-frequency-high");
551 pfunc_cpu_setfreq_low =
552 pmf_find_function(hwclock, "set-frequency-low");
554 pmf_find_function(hwclock, "slewing-done");
555 pfunc_cpu0_volt_high =
556 pmf_find_function(hwclock, "set-voltage-high-0");
557 pfunc_cpu0_volt_low =
558 pmf_find_function(hwclock, "set-voltage-low-0");
559 pfunc_cpu1_volt_high =
560 pmf_find_function(hwclock, "set-voltage-high-1");
561 pfunc_cpu1_volt_low =
562 pmf_find_function(hwclock, "set-voltage-low-1");
564 /* Check we have minimum requirements */
565 if (pfunc_cpu_getfreq == NULL || pfunc_cpu_setfreq_high == NULL ||
566 pfunc_cpu_setfreq_low == NULL || pfunc_slewing_done == NULL) {
567 printk(KERN_ERR "cpufreq: Can't find platform functions !\n");
572 /* Check that we have complete sets */
573 if (pfunc_cpu0_volt_high == NULL || pfunc_cpu0_volt_low == NULL) {
574 pmf_put_function(pfunc_cpu0_volt_high);
575 pmf_put_function(pfunc_cpu0_volt_low);
576 pfunc_cpu0_volt_high = pfunc_cpu0_volt_low = NULL;
580 pfunc_cpu1_volt_high == NULL || pfunc_cpu1_volt_low == NULL) {
581 pmf_put_function(pfunc_cpu1_volt_high);
582 pmf_put_function(pfunc_cpu1_volt_low);
583 pfunc_cpu1_volt_high = pfunc_cpu1_volt_low = NULL;
586 /* Note: The device tree also contains a "platform-set-values"
587 * function for which I haven't quite figured out the usage. It
588 * might have to be called on init and/or wakeup, I'm not too sure
589 * but things seem to work fine without it so far ...
592 /* Get max frequency from device-tree */
593 valp = of_get_property(cpunode, "clock-frequency", NULL);
595 printk(KERN_ERR "cpufreq: Can't find CPU frequency !\n");
600 max_freq = (*valp)/1000;
602 /* Now calculate reduced frequency by using the cpuid input freq
603 * ratio. This requires 64 bits math unless we are willing to lose
606 ih = *((u32 *)(eeprom + 0x10));
607 il = *((u32 *)(eeprom + 0x20));
609 /* Check for machines with no useful settings */
611 printk(KERN_WARNING "cpufreq: No low frequency mode available"
612 " on this model !\n");
618 if (ih != 0 && il != 0)
619 min_freq = (max_freq * il) / ih;
622 if (min_freq >= max_freq || min_freq < 1000) {
623 printk(KERN_ERR "cpufreq: Can't calculate low frequency !\n");
627 g5_cpu_freqs[0].frequency = max_freq;
628 g5_cpu_freqs[1].frequency = min_freq;
631 transition_latency = CPUFREQ_ETERNAL;
632 g5_switch_volt = g5_pfunc_switch_volt;
633 g5_switch_freq = g5_pfunc_switch_freq;
634 g5_query_freq = g5_pfunc_query_freq;
636 /* Force apply current frequency to make sure everything is in
637 * sync (voltage is right for example). Firmware may leave us with
638 * a strange setting ...
640 g5_switch_volt(CPUFREQ_HIGH);
643 g5_switch_freq(g5_query_freq());
645 printk(KERN_INFO "Registering G5 CPU frequency driver\n");
646 printk(KERN_INFO "Frequency method: i2c/pfunc, "
647 "Voltage method: %s\n", has_volt ? "i2c/pfunc" : "none");
648 printk(KERN_INFO "Low: %d Mhz, High: %d Mhz, Cur: %d MHz\n",
649 g5_cpu_freqs[1].frequency/1000,
650 g5_cpu_freqs[0].frequency/1000,
651 g5_cpu_freqs[g5_pmode_cur].frequency/1000);
653 rc = cpufreq_register_driver(&g5_cpufreq_driver);
656 pmf_put_function(pfunc_cpu_getfreq);
657 pmf_put_function(pfunc_cpu_setfreq_high);
658 pmf_put_function(pfunc_cpu_setfreq_low);
659 pmf_put_function(pfunc_slewing_done);
660 pmf_put_function(pfunc_cpu0_volt_high);
661 pmf_put_function(pfunc_cpu0_volt_low);
662 pmf_put_function(pfunc_cpu1_volt_high);
663 pmf_put_function(pfunc_cpu1_volt_low);
665 of_node_put(hwclock);
667 of_node_put(cpunode);
672 static int __init g5_cpufreq_init(void)
674 struct device_node *cpunode;
677 /* Get first CPU node */
678 cpunode = of_cpu_device_node_get(0);
679 if (cpunode == NULL) {
680 pr_err("cpufreq: Can't find any CPU node\n");
684 if (of_machine_is_compatible("PowerMac7,2") ||
685 of_machine_is_compatible("PowerMac7,3") ||
686 of_machine_is_compatible("RackMac3,1"))
687 rc = g5_pm72_cpufreq_init(cpunode);
688 #ifdef CONFIG_PMAC_SMU
690 rc = g5_neo2_cpufreq_init(cpunode);
691 #endif /* CONFIG_PMAC_SMU */
696 module_init(g5_cpufreq_init);
699 MODULE_LICENSE("GPL");