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>
28 #include <linux/of_device.h>
30 #include <asm/machdep.h>
32 #include <asm/pmac_feature.h>
33 #include <asm/mmu_context.h>
34 #include <asm/sections.h>
35 #include <asm/cputable.h>
38 #include <asm/keylargo.h>
39 #include <asm/switch_to.h>
41 /* WARNING !!! This will cause calibrate_delay() to be called,
42 * but this is an __init function ! So you MUST go edit
43 * init/main.c to make it non-init before enabling DEBUG_FREQ
47 extern void low_choose_7447a_dfs(int dfs
);
48 extern void low_choose_750fx_pll(int pll
);
49 extern void low_sleep_handler(void);
52 * Currently, PowerMac cpufreq supports only high & low frequencies
53 * that are set by the firmware
55 static unsigned int low_freq
;
56 static unsigned int hi_freq
;
57 static unsigned int cur_freq
;
58 static unsigned int sleep_freq
;
59 static unsigned long transition_latency
;
62 * Different models uses different mechanisms to switch the frequency
64 static int (*set_speed_proc
)(int low_speed
);
65 static unsigned int (*get_speed_proc
)(void);
68 * Some definitions used by the various speedprocs
70 static u32 voltage_gpio
;
71 static u32 frequency_gpio
;
72 static u32 slew_done_gpio
;
73 static int no_schedule
;
74 static int has_cpu_l2lve
;
75 static int is_pmu_based
;
77 /* There are only two frequency states for each processor. Values
78 * are in kHz for the time being.
80 #define CPUFREQ_HIGH 0
83 static struct cpufreq_frequency_table pmac_cpu_freqs
[] = {
86 {0, CPUFREQ_TABLE_END
},
89 static inline void local_delay(unsigned long ms
)
98 static inline void debug_calc_bogomips(void)
100 /* This will cause a recalc of bogomips and display the
101 * result. We backup/restore the value to avoid affecting the
102 * core cpufreq framework's own calculation.
104 unsigned long save_lpj
= loops_per_jiffy
;
106 loops_per_jiffy
= save_lpj
;
108 #endif /* DEBUG_FREQ */
110 /* Switch CPU speed under 750FX CPU control
112 static int cpu_750fx_cpu_speed(int low_speed
)
116 if (low_speed
== 0) {
117 /* ramping up, set voltage first */
118 pmac_call_feature(PMAC_FTR_WRITE_GPIO
, NULL
, voltage_gpio
, 0x05);
119 /* Make sure we sleep for at least 1ms */
122 /* tweak L2 for high voltage */
124 hid2
= mfspr(SPRN_HID2
);
126 mtspr(SPRN_HID2
, hid2
);
130 low_choose_750fx_pll(low_speed
);
132 if (low_speed
== 1) {
133 /* tweak L2 for low voltage */
135 hid2
= mfspr(SPRN_HID2
);
137 mtspr(SPRN_HID2
, hid2
);
140 /* ramping down, set voltage last */
141 pmac_call_feature(PMAC_FTR_WRITE_GPIO
, NULL
, voltage_gpio
, 0x04);
148 static unsigned int cpu_750fx_get_cpu_speed(void)
150 if (mfspr(SPRN_HID1
) & HID1_PS
)
156 /* Switch CPU speed using DFS */
157 static int dfs_set_cpu_speed(int low_speed
)
159 if (low_speed
== 0) {
160 /* ramping up, set voltage first */
161 pmac_call_feature(PMAC_FTR_WRITE_GPIO
, NULL
, voltage_gpio
, 0x05);
162 /* Make sure we sleep for at least 1ms */
168 low_choose_7447a_dfs(low_speed
);
172 if (low_speed
== 1) {
173 /* ramping down, set voltage last */
174 pmac_call_feature(PMAC_FTR_WRITE_GPIO
, NULL
, voltage_gpio
, 0x04);
181 static unsigned int dfs_get_cpu_speed(void)
183 if (mfspr(SPRN_HID1
) & HID1_DFS
)
190 /* Switch CPU speed using slewing GPIOs
192 static int gpios_set_cpu_speed(int low_speed
)
194 int gpio
, timeout
= 0;
196 /* If ramping up, set voltage first */
197 if (low_speed
== 0) {
198 pmac_call_feature(PMAC_FTR_WRITE_GPIO
, NULL
, voltage_gpio
, 0x05);
199 /* Delay is way too big but it's ok, we schedule */
204 gpio
= pmac_call_feature(PMAC_FTR_READ_GPIO
, NULL
, frequency_gpio
, 0);
205 if (low_speed
== ((gpio
& 0x01) == 0))
208 pmac_call_feature(PMAC_FTR_WRITE_GPIO
, NULL
, frequency_gpio
,
209 low_speed
? 0x04 : 0x05);
215 gpio
= pmac_call_feature(PMAC_FTR_READ_GPIO
, NULL
, slew_done_gpio
, 0);
216 } while((gpio
& 0x02) == 0);
218 /* If ramping down, set voltage last */
219 if (low_speed
== 1) {
220 pmac_call_feature(PMAC_FTR_WRITE_GPIO
, NULL
, voltage_gpio
, 0x04);
221 /* Delay is way too big but it's ok, we schedule */
226 debug_calc_bogomips();
232 /* Switch CPU speed under PMU control
234 static int pmu_set_cpu_speed(int low_speed
)
236 struct adb_request req
;
237 unsigned long save_l2cr
;
238 unsigned long save_l3cr
;
239 unsigned int pic_prio
;
245 printk(KERN_DEBUG
"HID1, before: %x\n", mfspr(SPRN_HID1
));
249 /* Disable all interrupt sources on openpic */
250 pic_prio
= mpic_cpu_get_priority();
251 mpic_cpu_set_priority(0xf);
253 /* Make sure the decrementer won't interrupt us */
254 asm volatile("mtdec %0" : : "r" (0x7fffffff));
255 /* Make sure any pending DEC interrupt occurring while we did
256 * the above didn't re-enable the DEC */
258 asm volatile("mtdec %0" : : "r" (0x7fffffff));
260 /* We can now disable MSR_EE */
261 local_irq_save(flags
);
263 /* Giveup the FPU & vec */
266 #ifdef CONFIG_ALTIVEC
267 if (cpu_has_feature(CPU_FTR_ALTIVEC
))
268 enable_kernel_altivec();
269 #endif /* CONFIG_ALTIVEC */
271 /* Save & disable L2 and L3 caches */
272 save_l3cr
= _get_L3CR(); /* (returns -1 if not available) */
273 save_l2cr
= _get_L2CR(); /* (returns -1 if not available) */
275 /* Send the new speed command. My assumption is that this command
276 * will cause PLL_CFG[0..3] to be changed next time CPU goes to sleep
278 pmu_request(&req
, NULL
, 6, PMU_CPU_SPEED
, 'W', 'O', 'O', 'F', low_speed
);
279 while (!req
.complete
)
282 /* Prepare the northbridge for the speed transition */
283 pmac_call_feature(PMAC_FTR_SLEEP_STATE
,NULL
,1,1);
285 /* Call low level code to backup CPU state and recover from
290 /* Restore the northbridge */
291 pmac_call_feature(PMAC_FTR_SLEEP_STATE
,NULL
,1,0);
293 /* Restore L2 cache */
294 if (save_l2cr
!= 0xffffffff && (save_l2cr
& L2CR_L2E
) != 0)
295 _set_L2CR(save_l2cr
);
296 /* Restore L3 cache */
297 if (save_l3cr
!= 0xffffffff && (save_l3cr
& L3CR_L3E
) != 0)
298 _set_L3CR(save_l3cr
);
300 /* Restore userland MMU context */
301 switch_mmu_context(NULL
, current
->active_mm
);
304 printk(KERN_DEBUG
"HID1, after: %x\n", mfspr(SPRN_HID1
));
307 /* Restore low level PMU operations */
311 * Restore decrementer; we'll take a decrementer interrupt
312 * as soon as interrupts are re-enabled and the generic
313 * clockevents code will reprogram it with the right value.
317 /* Restore interrupts */
318 mpic_cpu_set_priority(pic_prio
);
320 /* Let interrupts flow again ... */
321 local_irq_restore(flags
);
324 debug_calc_bogomips();
334 static int do_set_cpu_speed(struct cpufreq_policy
*policy
, int speed_mode
,
337 struct cpufreq_freqs freqs
;
339 static unsigned long prev_l3cr
;
341 freqs
.old
= cur_freq
;
342 freqs
.new = (speed_mode
== CPUFREQ_HIGH
) ? hi_freq
: low_freq
;
344 if (freqs
.old
== freqs
.new)
348 cpufreq_notify_transition(policy
, &freqs
, CPUFREQ_PRECHANGE
);
349 if (speed_mode
== CPUFREQ_LOW
&&
350 cpu_has_feature(CPU_FTR_L3CR
)) {
352 if (l3cr
& L3CR_L3E
) {
357 set_speed_proc(speed_mode
== CPUFREQ_LOW
);
358 if (speed_mode
== CPUFREQ_HIGH
&&
359 cpu_has_feature(CPU_FTR_L3CR
)) {
361 if ((prev_l3cr
& L3CR_L3E
) && l3cr
!= prev_l3cr
)
362 _set_L3CR(prev_l3cr
);
365 cpufreq_notify_transition(policy
, &freqs
, CPUFREQ_POSTCHANGE
);
366 cur_freq
= (speed_mode
== CPUFREQ_HIGH
) ? hi_freq
: low_freq
;
371 static unsigned int pmac_cpufreq_get_speed(unsigned int cpu
)
376 static int pmac_cpufreq_target( struct cpufreq_policy
*policy
,
381 rc
= do_set_cpu_speed(policy
, index
, 1);
383 ppc_proc_freq
= cur_freq
* 1000ul;
387 static int pmac_cpufreq_cpu_init(struct cpufreq_policy
*policy
)
389 return cpufreq_generic_init(policy
, pmac_cpu_freqs
, transition_latency
);
392 static u32
read_gpio(struct device_node
*np
)
394 const u32
*reg
= of_get_property(np
, "reg", NULL
);
399 /* That works for all keylargos but shall be fixed properly
400 * some day... The problem is that it seems we can't rely
401 * on the "reg" property of the GPIO nodes, they are either
402 * relative to the base of KeyLargo or to the base of the
403 * GPIO space, and the device-tree doesn't help.
406 if (offset
< KEYLARGO_GPIO_LEVELS0
)
407 offset
+= KEYLARGO_GPIO_LEVELS0
;
411 static int pmac_cpufreq_suspend(struct cpufreq_policy
*policy
)
413 /* Ok, this could be made a bit smarter, but let's be robust for now. We
414 * always force a speed change to high speed before sleep, to make sure
415 * we have appropriate voltage and/or bus speed for the wakeup process,
416 * and to make sure our loops_per_jiffies are "good enough", that is will
417 * not cause too short delays if we sleep in low speed and wake in high
421 sleep_freq
= cur_freq
;
422 if (cur_freq
== low_freq
&& !is_pmu_based
)
423 do_set_cpu_speed(policy
, CPUFREQ_HIGH
, 0);
427 static int pmac_cpufreq_resume(struct cpufreq_policy
*policy
)
429 /* If we resume, first check if we have a get() function */
431 cur_freq
= get_speed_proc();
435 /* We don't, hrm... we don't really know our speed here, best
436 * is that we force a switch to whatever it was, which is
437 * probably high speed due to our suspend() routine
439 do_set_cpu_speed(policy
, sleep_freq
== low_freq
?
440 CPUFREQ_LOW
: CPUFREQ_HIGH
, 0);
442 ppc_proc_freq
= cur_freq
* 1000ul;
448 static struct cpufreq_driver pmac_cpufreq_driver
= {
449 .verify
= cpufreq_generic_frequency_table_verify
,
450 .target_index
= pmac_cpufreq_target
,
451 .get
= pmac_cpufreq_get_speed
,
452 .init
= pmac_cpufreq_cpu_init
,
453 .suspend
= pmac_cpufreq_suspend
,
454 .resume
= pmac_cpufreq_resume
,
455 .flags
= CPUFREQ_PM_NO_WARN
,
456 .attr
= cpufreq_generic_attr
,
461 static int pmac_cpufreq_init_MacRISC3(struct device_node
*cpunode
)
463 struct device_node
*volt_gpio_np
= of_find_node_by_name(NULL
,
465 struct device_node
*freq_gpio_np
= of_find_node_by_name(NULL
,
467 struct device_node
*slew_done_gpio_np
= of_find_node_by_name(NULL
,
472 * Check to see if it's GPIO driven or PMU only
474 * The way we extract the GPIO address is slightly hackish, but it
475 * works well enough for now. We need to abstract the whole GPIO
476 * stuff sooner or later anyway
480 voltage_gpio
= read_gpio(volt_gpio_np
);
482 frequency_gpio
= read_gpio(freq_gpio_np
);
483 if (slew_done_gpio_np
)
484 slew_done_gpio
= read_gpio(slew_done_gpio_np
);
486 /* If we use the frequency GPIOs, calculate the min/max speeds based
487 * on the bus frequencies
489 if (frequency_gpio
&& slew_done_gpio
) {
491 const u32
*freqs
, *ratio
;
493 freqs
= of_get_property(cpunode
, "bus-frequencies", &lenp
);
495 if (freqs
== NULL
|| lenp
!= 2) {
496 printk(KERN_ERR
"cpufreq: bus-frequencies incorrect or missing\n");
499 ratio
= of_get_property(cpunode
, "processor-to-bus-ratio*2",
502 printk(KERN_ERR
"cpufreq: processor-to-bus-ratio*2 missing\n");
506 /* Get the min/max bus frequencies */
507 low_freq
= min(freqs
[0], freqs
[1]);
508 hi_freq
= max(freqs
[0], freqs
[1]);
510 /* Grrrr.. It _seems_ that the device-tree is lying on the low bus
511 * frequency, it claims it to be around 84Mhz on some models while
512 * it appears to be approx. 101Mhz on all. Let's hack around here...
513 * fortunately, we don't need to be too precise
515 if (low_freq
< 98000000)
516 low_freq
= 101000000;
518 /* Convert those to CPU core clocks */
519 low_freq
= (low_freq
* (*ratio
)) / 2000;
520 hi_freq
= (hi_freq
* (*ratio
)) / 2000;
522 /* Now we get the frequencies, we read the GPIO to see what is out current
525 rc
= pmac_call_feature(PMAC_FTR_READ_GPIO
, NULL
, frequency_gpio
, 0);
526 cur_freq
= (rc
& 0x01) ? hi_freq
: low_freq
;
528 set_speed_proc
= gpios_set_cpu_speed
;
532 /* If we use the PMU, look for the min & max frequencies in the
535 value
= of_get_property(cpunode
, "min-clock-frequency", NULL
);
538 low_freq
= (*value
) / 1000;
539 /* The PowerBook G4 12" (PowerBook6,1) has an error in the device-tree
541 if (low_freq
< 100000)
544 value
= of_get_property(cpunode
, "max-clock-frequency", NULL
);
547 hi_freq
= (*value
) / 1000;
548 set_speed_proc
= pmu_set_cpu_speed
;
554 static int pmac_cpufreq_init_7447A(struct device_node
*cpunode
)
556 struct device_node
*volt_gpio_np
;
558 if (of_get_property(cpunode
, "dynamic-power-step", NULL
) == NULL
)
561 volt_gpio_np
= of_find_node_by_name(NULL
, "cpu-vcore-select");
563 voltage_gpio
= read_gpio(volt_gpio_np
);
565 printk(KERN_ERR
"cpufreq: missing cpu-vcore-select gpio\n");
569 /* OF only reports the high frequency */
571 low_freq
= cur_freq
/2;
573 /* Read actual frequency from CPU */
574 cur_freq
= dfs_get_cpu_speed();
575 set_speed_proc
= dfs_set_cpu_speed
;
576 get_speed_proc
= dfs_get_cpu_speed
;
581 static int pmac_cpufreq_init_750FX(struct device_node
*cpunode
)
583 struct device_node
*volt_gpio_np
;
587 if (of_get_property(cpunode
, "dynamic-power-step", NULL
) == NULL
)
591 value
= of_get_property(cpunode
, "reduced-clock-frequency", NULL
);
594 low_freq
= (*value
) / 1000;
596 volt_gpio_np
= of_find_node_by_name(NULL
, "cpu-vcore-select");
598 voltage_gpio
= read_gpio(volt_gpio_np
);
600 pvr
= mfspr(SPRN_PVR
);
601 has_cpu_l2lve
= !((pvr
& 0xf00) == 0x100);
603 set_speed_proc
= cpu_750fx_cpu_speed
;
604 get_speed_proc
= cpu_750fx_get_cpu_speed
;
605 cur_freq
= cpu_750fx_get_cpu_speed();
610 /* Currently, we support the following machines:
612 * - Titanium PowerBook 1Ghz (PMU based, 667Mhz & 1Ghz)
613 * - Titanium PowerBook 800 (PMU based, 667Mhz & 800Mhz)
614 * - Titanium PowerBook 400 (PMU based, 300Mhz & 400Mhz)
615 * - Titanium PowerBook 500 (PMU based, 300Mhz & 500Mhz)
616 * - iBook2 500/600 (PMU based, 400Mhz & 500/600Mhz)
617 * - iBook2 700 (CPU based, 400Mhz & 700Mhz, support low voltage)
618 * - Recent MacRISC3 laptops
619 * - All new machines with 7447A CPUs
621 static int __init
pmac_cpufreq_setup(void)
623 struct device_node
*cpunode
;
626 if (strstr(cmd_line
, "nocpufreq"))
629 /* Get first CPU node */
630 cpunode
= of_cpu_device_node_get(0);
634 /* Get current cpu clock freq */
635 value
= of_get_property(cpunode
, "clock-frequency", NULL
);
638 cur_freq
= (*value
) / 1000;
639 transition_latency
= CPUFREQ_ETERNAL
;
641 /* Check for 7447A based MacRISC3 */
642 if (of_machine_is_compatible("MacRISC3") &&
643 of_get_property(cpunode
, "dynamic-power-step", NULL
) &&
644 PVR_VER(mfspr(SPRN_PVR
)) == 0x8003) {
645 pmac_cpufreq_init_7447A(cpunode
);
646 transition_latency
= 8000000;
647 /* Check for other MacRISC3 machines */
648 } else if (of_machine_is_compatible("PowerBook3,4") ||
649 of_machine_is_compatible("PowerBook3,5") ||
650 of_machine_is_compatible("MacRISC3")) {
651 pmac_cpufreq_init_MacRISC3(cpunode
);
652 /* Else check for iBook2 500/600 */
653 } else if (of_machine_is_compatible("PowerBook4,1")) {
656 set_speed_proc
= pmu_set_cpu_speed
;
659 /* Else check for TiPb 550 */
660 else if (of_machine_is_compatible("PowerBook3,3") && cur_freq
== 550000) {
663 set_speed_proc
= pmu_set_cpu_speed
;
666 /* Else check for TiPb 400 & 500 */
667 else if (of_machine_is_compatible("PowerBook3,2")) {
668 /* We only know about the 400 MHz and the 500Mhz model
669 * they both have 300 MHz as low frequency
671 if (cur_freq
< 350000 || cur_freq
> 550000)
675 set_speed_proc
= pmu_set_cpu_speed
;
678 /* Else check for 750FX */
679 else if (PVR_VER(mfspr(SPRN_PVR
)) == 0x7000)
680 pmac_cpufreq_init_750FX(cpunode
);
682 of_node_put(cpunode
);
683 if (set_speed_proc
== NULL
)
686 pmac_cpu_freqs
[CPUFREQ_LOW
].frequency
= low_freq
;
687 pmac_cpu_freqs
[CPUFREQ_HIGH
].frequency
= hi_freq
;
688 ppc_proc_freq
= cur_freq
* 1000ul;
690 printk(KERN_INFO
"Registering PowerMac CPU frequency driver\n");
691 printk(KERN_INFO
"Low: %d Mhz, High: %d Mhz, Boot: %d Mhz\n",
692 low_freq
/1000, hi_freq
/1000, cur_freq
/1000);
694 return cpufreq_register_driver(&pmac_cpufreq_driver
);
697 module_init(pmac_cpufreq_setup
);