2 * Copyright (C) 2002 - 2005 Benjamin Herrenschmidt <benh@kernel.crashing.org>
3 * Copyright (C) 2004 John Steele Scott <toojays@toojays.net>
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 * 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
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>
29 #include <asm/machdep.h>
31 #include <asm/pmac_feature.h>
32 #include <asm/mmu_context.h>
33 #include <asm/sections.h>
34 #include <asm/cputable.h>
37 #include <asm/keylargo.h>
38 #include <asm/switch_to.h>
40 /* WARNING !!! This will cause calibrate_delay() to be called,
41 * but this is an __init function ! So you MUST go edit
42 * init/main.c to make it non-init before enabling DEBUG_FREQ
46 extern void low_choose_7447a_dfs(int dfs
);
47 extern void low_choose_750fx_pll(int pll
);
48 extern void low_sleep_handler(void);
51 * Currently, PowerMac cpufreq supports only high & low frequencies
52 * that are set by the firmware
54 static unsigned int low_freq
;
55 static unsigned int hi_freq
;
56 static unsigned int cur_freq
;
57 static unsigned int sleep_freq
;
58 static unsigned long transition_latency
;
61 * Different models uses different mechanisms to switch the frequency
63 static int (*set_speed_proc
)(int low_speed
);
64 static unsigned int (*get_speed_proc
)(void);
67 * Some definitions used by the various speedprocs
69 static u32 voltage_gpio
;
70 static u32 frequency_gpio
;
71 static u32 slew_done_gpio
;
72 static int no_schedule
;
73 static int has_cpu_l2lve
;
74 static int is_pmu_based
;
76 /* There are only two frequency states for each processor. Values
77 * are in kHz for the time being.
79 #define CPUFREQ_HIGH 0
82 static struct cpufreq_frequency_table pmac_cpu_freqs
[] = {
85 {0, CPUFREQ_TABLE_END
},
88 static struct freq_attr
* pmac_cpu_freqs_attr
[] = {
89 &cpufreq_freq_attr_scaling_available_freqs
,
93 static inline void local_delay(unsigned long ms
)
102 static inline void debug_calc_bogomips(void)
104 /* This will cause a recalc of bogomips and display the
105 * result. We backup/restore the value to avoid affecting the
106 * core cpufreq framework's own calculation.
108 unsigned long save_lpj
= loops_per_jiffy
;
110 loops_per_jiffy
= save_lpj
;
112 #endif /* DEBUG_FREQ */
114 /* Switch CPU speed under 750FX CPU control
116 static int cpu_750fx_cpu_speed(int low_speed
)
120 if (low_speed
== 0) {
121 /* ramping up, set voltage first */
122 pmac_call_feature(PMAC_FTR_WRITE_GPIO
, NULL
, voltage_gpio
, 0x05);
123 /* Make sure we sleep for at least 1ms */
126 /* tweak L2 for high voltage */
128 hid2
= mfspr(SPRN_HID2
);
130 mtspr(SPRN_HID2
, hid2
);
134 low_choose_750fx_pll(low_speed
);
136 if (low_speed
== 1) {
137 /* tweak L2 for low voltage */
139 hid2
= mfspr(SPRN_HID2
);
141 mtspr(SPRN_HID2
, hid2
);
144 /* ramping down, set voltage last */
145 pmac_call_feature(PMAC_FTR_WRITE_GPIO
, NULL
, voltage_gpio
, 0x04);
152 static unsigned int cpu_750fx_get_cpu_speed(void)
154 if (mfspr(SPRN_HID1
) & HID1_PS
)
160 /* Switch CPU speed using DFS */
161 static int dfs_set_cpu_speed(int low_speed
)
163 if (low_speed
== 0) {
164 /* ramping up, set voltage first */
165 pmac_call_feature(PMAC_FTR_WRITE_GPIO
, NULL
, voltage_gpio
, 0x05);
166 /* Make sure we sleep for at least 1ms */
172 low_choose_7447a_dfs(low_speed
);
176 if (low_speed
== 1) {
177 /* ramping down, set voltage last */
178 pmac_call_feature(PMAC_FTR_WRITE_GPIO
, NULL
, voltage_gpio
, 0x04);
185 static unsigned int dfs_get_cpu_speed(void)
187 if (mfspr(SPRN_HID1
) & HID1_DFS
)
194 /* Switch CPU speed using slewing GPIOs
196 static int gpios_set_cpu_speed(int low_speed
)
198 int gpio
, timeout
= 0;
200 /* If ramping up, set voltage first */
201 if (low_speed
== 0) {
202 pmac_call_feature(PMAC_FTR_WRITE_GPIO
, NULL
, voltage_gpio
, 0x05);
203 /* Delay is way too big but it's ok, we schedule */
208 gpio
= pmac_call_feature(PMAC_FTR_READ_GPIO
, NULL
, frequency_gpio
, 0);
209 if (low_speed
== ((gpio
& 0x01) == 0))
212 pmac_call_feature(PMAC_FTR_WRITE_GPIO
, NULL
, frequency_gpio
,
213 low_speed
? 0x04 : 0x05);
219 gpio
= pmac_call_feature(PMAC_FTR_READ_GPIO
, NULL
, slew_done_gpio
, 0);
220 } while((gpio
& 0x02) == 0);
222 /* If ramping down, set voltage last */
223 if (low_speed
== 1) {
224 pmac_call_feature(PMAC_FTR_WRITE_GPIO
, NULL
, voltage_gpio
, 0x04);
225 /* Delay is way too big but it's ok, we schedule */
230 debug_calc_bogomips();
236 /* Switch CPU speed under PMU control
238 static int pmu_set_cpu_speed(int low_speed
)
240 struct adb_request req
;
241 unsigned long save_l2cr
;
242 unsigned long save_l3cr
;
243 unsigned int pic_prio
;
249 printk(KERN_DEBUG
"HID1, before: %x\n", mfspr(SPRN_HID1
));
253 /* Disable all interrupt sources on openpic */
254 pic_prio
= mpic_cpu_get_priority();
255 mpic_cpu_set_priority(0xf);
257 /* Make sure the decrementer won't interrupt us */
258 asm volatile("mtdec %0" : : "r" (0x7fffffff));
259 /* Make sure any pending DEC interrupt occurring while we did
260 * the above didn't re-enable the DEC */
262 asm volatile("mtdec %0" : : "r" (0x7fffffff));
264 /* We can now disable MSR_EE */
265 local_irq_save(flags
);
267 /* Giveup the FPU & vec */
270 #ifdef CONFIG_ALTIVEC
271 if (cpu_has_feature(CPU_FTR_ALTIVEC
))
272 enable_kernel_altivec();
273 #endif /* CONFIG_ALTIVEC */
275 /* Save & disable L2 and L3 caches */
276 save_l3cr
= _get_L3CR(); /* (returns -1 if not available) */
277 save_l2cr
= _get_L2CR(); /* (returns -1 if not available) */
279 /* Send the new speed command. My assumption is that this command
280 * will cause PLL_CFG[0..3] to be changed next time CPU goes to sleep
282 pmu_request(&req
, NULL
, 6, PMU_CPU_SPEED
, 'W', 'O', 'O', 'F', low_speed
);
283 while (!req
.complete
)
286 /* Prepare the northbridge for the speed transition */
287 pmac_call_feature(PMAC_FTR_SLEEP_STATE
,NULL
,1,1);
289 /* Call low level code to backup CPU state and recover from
294 /* Restore the northbridge */
295 pmac_call_feature(PMAC_FTR_SLEEP_STATE
,NULL
,1,0);
297 /* Restore L2 cache */
298 if (save_l2cr
!= 0xffffffff && (save_l2cr
& L2CR_L2E
) != 0)
299 _set_L2CR(save_l2cr
);
300 /* Restore L3 cache */
301 if (save_l3cr
!= 0xffffffff && (save_l3cr
& L3CR_L3E
) != 0)
302 _set_L3CR(save_l3cr
);
304 /* Restore userland MMU context */
305 switch_mmu_context(NULL
, current
->active_mm
);
308 printk(KERN_DEBUG
"HID1, after: %x\n", mfspr(SPRN_HID1
));
311 /* Restore low level PMU operations */
315 * Restore decrementer; we'll take a decrementer interrupt
316 * as soon as interrupts are re-enabled and the generic
317 * clockevents code will reprogram it with the right value.
321 /* Restore interrupts */
322 mpic_cpu_set_priority(pic_prio
);
324 /* Let interrupts flow again ... */
325 local_irq_restore(flags
);
328 debug_calc_bogomips();
338 static int do_set_cpu_speed(int speed_mode
, int notify
)
340 struct cpufreq_freqs freqs
;
342 static unsigned long prev_l3cr
;
344 freqs
.old
= cur_freq
;
345 freqs
.new = (speed_mode
== CPUFREQ_HIGH
) ? hi_freq
: low_freq
;
346 freqs
.cpu
= smp_processor_id();
348 if (freqs
.old
== freqs
.new)
352 cpufreq_notify_transition(&freqs
, CPUFREQ_PRECHANGE
);
353 if (speed_mode
== CPUFREQ_LOW
&&
354 cpu_has_feature(CPU_FTR_L3CR
)) {
356 if (l3cr
& L3CR_L3E
) {
361 set_speed_proc(speed_mode
== CPUFREQ_LOW
);
362 if (speed_mode
== CPUFREQ_HIGH
&&
363 cpu_has_feature(CPU_FTR_L3CR
)) {
365 if ((prev_l3cr
& L3CR_L3E
) && l3cr
!= prev_l3cr
)
366 _set_L3CR(prev_l3cr
);
369 cpufreq_notify_transition(&freqs
, CPUFREQ_POSTCHANGE
);
370 cur_freq
= (speed_mode
== CPUFREQ_HIGH
) ? hi_freq
: low_freq
;
375 static unsigned int pmac_cpufreq_get_speed(unsigned int cpu
)
380 static int pmac_cpufreq_verify(struct cpufreq_policy
*policy
)
382 return cpufreq_frequency_table_verify(policy
, pmac_cpu_freqs
);
385 static int pmac_cpufreq_target( struct cpufreq_policy
*policy
,
386 unsigned int target_freq
,
387 unsigned int relation
)
389 unsigned int newstate
= 0;
392 if (cpufreq_frequency_table_target(policy
, pmac_cpu_freqs
,
393 target_freq
, relation
, &newstate
))
396 rc
= do_set_cpu_speed(newstate
, 1);
398 ppc_proc_freq
= cur_freq
* 1000ul;
402 static int pmac_cpufreq_cpu_init(struct cpufreq_policy
*policy
)
404 if (policy
->cpu
!= 0)
407 policy
->cpuinfo
.transition_latency
= transition_latency
;
408 policy
->cur
= cur_freq
;
410 cpufreq_frequency_table_get_attr(pmac_cpu_freqs
, policy
->cpu
);
411 return cpufreq_frequency_table_cpuinfo(policy
, pmac_cpu_freqs
);
414 static u32
read_gpio(struct device_node
*np
)
416 const u32
*reg
= of_get_property(np
, "reg", NULL
);
421 /* That works for all keylargos but shall be fixed properly
422 * some day... The problem is that it seems we can't rely
423 * on the "reg" property of the GPIO nodes, they are either
424 * relative to the base of KeyLargo or to the base of the
425 * GPIO space, and the device-tree doesn't help.
428 if (offset
< KEYLARGO_GPIO_LEVELS0
)
429 offset
+= KEYLARGO_GPIO_LEVELS0
;
433 static int pmac_cpufreq_suspend(struct cpufreq_policy
*policy
)
435 /* Ok, this could be made a bit smarter, but let's be robust for now. We
436 * always force a speed change to high speed before sleep, to make sure
437 * we have appropriate voltage and/or bus speed for the wakeup process,
438 * and to make sure our loops_per_jiffies are "good enough", that is will
439 * not cause too short delays if we sleep in low speed and wake in high
443 sleep_freq
= cur_freq
;
444 if (cur_freq
== low_freq
&& !is_pmu_based
)
445 do_set_cpu_speed(CPUFREQ_HIGH
, 0);
449 static int pmac_cpufreq_resume(struct cpufreq_policy
*policy
)
451 /* If we resume, first check if we have a get() function */
453 cur_freq
= get_speed_proc();
457 /* We don't, hrm... we don't really know our speed here, best
458 * is that we force a switch to whatever it was, which is
459 * probably high speed due to our suspend() routine
461 do_set_cpu_speed(sleep_freq
== low_freq
?
462 CPUFREQ_LOW
: CPUFREQ_HIGH
, 0);
464 ppc_proc_freq
= cur_freq
* 1000ul;
470 static struct cpufreq_driver pmac_cpufreq_driver
= {
471 .verify
= pmac_cpufreq_verify
,
472 .target
= pmac_cpufreq_target
,
473 .get
= pmac_cpufreq_get_speed
,
474 .init
= pmac_cpufreq_cpu_init
,
475 .suspend
= pmac_cpufreq_suspend
,
476 .resume
= pmac_cpufreq_resume
,
477 .flags
= CPUFREQ_PM_NO_WARN
,
478 .attr
= pmac_cpu_freqs_attr
,
480 .owner
= THIS_MODULE
,
484 static int pmac_cpufreq_init_MacRISC3(struct device_node
*cpunode
)
486 struct device_node
*volt_gpio_np
= of_find_node_by_name(NULL
,
488 struct device_node
*freq_gpio_np
= of_find_node_by_name(NULL
,
490 struct device_node
*slew_done_gpio_np
= of_find_node_by_name(NULL
,
495 * Check to see if it's GPIO driven or PMU only
497 * The way we extract the GPIO address is slightly hackish, but it
498 * works well enough for now. We need to abstract the whole GPIO
499 * stuff sooner or later anyway
503 voltage_gpio
= read_gpio(volt_gpio_np
);
505 frequency_gpio
= read_gpio(freq_gpio_np
);
506 if (slew_done_gpio_np
)
507 slew_done_gpio
= read_gpio(slew_done_gpio_np
);
509 /* If we use the frequency GPIOs, calculate the min/max speeds based
510 * on the bus frequencies
512 if (frequency_gpio
&& slew_done_gpio
) {
514 const u32
*freqs
, *ratio
;
516 freqs
= of_get_property(cpunode
, "bus-frequencies", &lenp
);
518 if (freqs
== NULL
|| lenp
!= 2) {
519 printk(KERN_ERR
"cpufreq: bus-frequencies incorrect or missing\n");
522 ratio
= of_get_property(cpunode
, "processor-to-bus-ratio*2",
525 printk(KERN_ERR
"cpufreq: processor-to-bus-ratio*2 missing\n");
529 /* Get the min/max bus frequencies */
530 low_freq
= min(freqs
[0], freqs
[1]);
531 hi_freq
= max(freqs
[0], freqs
[1]);
533 /* Grrrr.. It _seems_ that the device-tree is lying on the low bus
534 * frequency, it claims it to be around 84Mhz on some models while
535 * it appears to be approx. 101Mhz on all. Let's hack around here...
536 * fortunately, we don't need to be too precise
538 if (low_freq
< 98000000)
539 low_freq
= 101000000;
541 /* Convert those to CPU core clocks */
542 low_freq
= (low_freq
* (*ratio
)) / 2000;
543 hi_freq
= (hi_freq
* (*ratio
)) / 2000;
545 /* Now we get the frequencies, we read the GPIO to see what is out current
548 rc
= pmac_call_feature(PMAC_FTR_READ_GPIO
, NULL
, frequency_gpio
, 0);
549 cur_freq
= (rc
& 0x01) ? hi_freq
: low_freq
;
551 set_speed_proc
= gpios_set_cpu_speed
;
555 /* If we use the PMU, look for the min & max frequencies in the
558 value
= of_get_property(cpunode
, "min-clock-frequency", NULL
);
561 low_freq
= (*value
) / 1000;
562 /* The PowerBook G4 12" (PowerBook6,1) has an error in the device-tree
564 if (low_freq
< 100000)
567 value
= of_get_property(cpunode
, "max-clock-frequency", NULL
);
570 hi_freq
= (*value
) / 1000;
571 set_speed_proc
= pmu_set_cpu_speed
;
577 static int pmac_cpufreq_init_7447A(struct device_node
*cpunode
)
579 struct device_node
*volt_gpio_np
;
581 if (of_get_property(cpunode
, "dynamic-power-step", NULL
) == NULL
)
584 volt_gpio_np
= of_find_node_by_name(NULL
, "cpu-vcore-select");
586 voltage_gpio
= read_gpio(volt_gpio_np
);
588 printk(KERN_ERR
"cpufreq: missing cpu-vcore-select gpio\n");
592 /* OF only reports the high frequency */
594 low_freq
= cur_freq
/2;
596 /* Read actual frequency from CPU */
597 cur_freq
= dfs_get_cpu_speed();
598 set_speed_proc
= dfs_set_cpu_speed
;
599 get_speed_proc
= dfs_get_cpu_speed
;
604 static int pmac_cpufreq_init_750FX(struct device_node
*cpunode
)
606 struct device_node
*volt_gpio_np
;
610 if (of_get_property(cpunode
, "dynamic-power-step", NULL
) == NULL
)
614 value
= of_get_property(cpunode
, "reduced-clock-frequency", NULL
);
617 low_freq
= (*value
) / 1000;
619 volt_gpio_np
= of_find_node_by_name(NULL
, "cpu-vcore-select");
621 voltage_gpio
= read_gpio(volt_gpio_np
);
623 pvr
= mfspr(SPRN_PVR
);
624 has_cpu_l2lve
= !((pvr
& 0xf00) == 0x100);
626 set_speed_proc
= cpu_750fx_cpu_speed
;
627 get_speed_proc
= cpu_750fx_get_cpu_speed
;
628 cur_freq
= cpu_750fx_get_cpu_speed();
633 /* Currently, we support the following machines:
635 * - Titanium PowerBook 1Ghz (PMU based, 667Mhz & 1Ghz)
636 * - Titanium PowerBook 800 (PMU based, 667Mhz & 800Mhz)
637 * - Titanium PowerBook 400 (PMU based, 300Mhz & 400Mhz)
638 * - Titanium PowerBook 500 (PMU based, 300Mhz & 500Mhz)
639 * - iBook2 500/600 (PMU based, 400Mhz & 500/600Mhz)
640 * - iBook2 700 (CPU based, 400Mhz & 700Mhz, support low voltage)
641 * - Recent MacRISC3 laptops
642 * - All new machines with 7447A CPUs
644 static int __init
pmac_cpufreq_setup(void)
646 struct device_node
*cpunode
;
649 if (strstr(cmd_line
, "nocpufreq"))
652 /* Assume only one CPU */
653 cpunode
= of_find_node_by_type(NULL
, "cpu");
657 /* Get current cpu clock freq */
658 value
= of_get_property(cpunode
, "clock-frequency", NULL
);
661 cur_freq
= (*value
) / 1000;
662 transition_latency
= CPUFREQ_ETERNAL
;
664 /* Check for 7447A based MacRISC3 */
665 if (of_machine_is_compatible("MacRISC3") &&
666 of_get_property(cpunode
, "dynamic-power-step", NULL
) &&
667 PVR_VER(mfspr(SPRN_PVR
)) == 0x8003) {
668 pmac_cpufreq_init_7447A(cpunode
);
669 transition_latency
= 8000000;
670 /* Check for other MacRISC3 machines */
671 } else if (of_machine_is_compatible("PowerBook3,4") ||
672 of_machine_is_compatible("PowerBook3,5") ||
673 of_machine_is_compatible("MacRISC3")) {
674 pmac_cpufreq_init_MacRISC3(cpunode
);
675 /* Else check for iBook2 500/600 */
676 } else if (of_machine_is_compatible("PowerBook4,1")) {
679 set_speed_proc
= pmu_set_cpu_speed
;
682 /* Else check for TiPb 550 */
683 else if (of_machine_is_compatible("PowerBook3,3") && cur_freq
== 550000) {
686 set_speed_proc
= pmu_set_cpu_speed
;
689 /* Else check for TiPb 400 & 500 */
690 else if (of_machine_is_compatible("PowerBook3,2")) {
691 /* We only know about the 400 MHz and the 500Mhz model
692 * they both have 300 MHz as low frequency
694 if (cur_freq
< 350000 || cur_freq
> 550000)
698 set_speed_proc
= pmu_set_cpu_speed
;
701 /* Else check for 750FX */
702 else if (PVR_VER(mfspr(SPRN_PVR
)) == 0x7000)
703 pmac_cpufreq_init_750FX(cpunode
);
705 of_node_put(cpunode
);
706 if (set_speed_proc
== NULL
)
709 pmac_cpu_freqs
[CPUFREQ_LOW
].frequency
= low_freq
;
710 pmac_cpu_freqs
[CPUFREQ_HIGH
].frequency
= hi_freq
;
711 ppc_proc_freq
= cur_freq
* 1000ul;
713 printk(KERN_INFO
"Registering PowerMac CPU frequency driver\n");
714 printk(KERN_INFO
"Low: %d Mhz, High: %d Mhz, Boot: %d Mhz\n",
715 low_freq
/1000, hi_freq
/1000, cur_freq
/1000);
717 return cpufreq_register_driver(&pmac_cpufreq_driver
);
720 module_init(pmac_cpufreq_setup
);