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/config.h>
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/adb.h>
24 #include <linux/pmu.h>
25 #include <linux/slab.h>
26 #include <linux/cpufreq.h>
27 #include <linux/init.h>
28 #include <linux/sysdev.h>
29 #include <linux/i2c.h>
30 #include <linux/hardirq.h>
32 #include <asm/machdep.h>
34 #include <asm/pmac_feature.h>
35 #include <asm/mmu_context.h>
36 #include <asm/sections.h>
37 #include <asm/cputable.h>
39 #include <asm/system.h>
41 #include <asm/keylargo.h>
43 /* WARNING !!! This will cause calibrate_delay() to be called,
44 * but this is an __init function ! So you MUST go edit
45 * init/main.c to make it non-init before enabling DEBUG_FREQ
50 * There is a problem with the core cpufreq code on SMP kernels,
51 * it won't recalculate the Bogomips properly
54 #warning "WARNING, CPUFREQ not recommended on SMP kernels"
57 extern void low_choose_7447a_dfs(int dfs
);
58 extern void low_choose_750fx_pll(int pll
);
59 extern void low_sleep_handler(void);
62 * Currently, PowerMac cpufreq supports only high & low frequencies
63 * that are set by the firmware
65 static unsigned int low_freq
;
66 static unsigned int hi_freq
;
67 static unsigned int cur_freq
;
68 static unsigned int sleep_freq
;
71 * Different models uses different mechanisms to switch the frequency
73 static int (*set_speed_proc
)(int low_speed
);
74 static unsigned int (*get_speed_proc
)(void);
77 * Some definitions used by the various speedprocs
79 static u32 voltage_gpio
;
80 static u32 frequency_gpio
;
81 static u32 slew_done_gpio
;
82 static int no_schedule
;
83 static int has_cpu_l2lve
;
84 static int is_pmu_based
;
86 /* There are only two frequency states for each processor. Values
87 * are in kHz for the time being.
89 #define CPUFREQ_HIGH 0
92 static struct cpufreq_frequency_table pmac_cpu_freqs
[] = {
95 {0, CPUFREQ_TABLE_END
},
98 static struct freq_attr
* pmac_cpu_freqs_attr
[] = {
99 &cpufreq_freq_attr_scaling_available_freqs
,
103 static inline void local_delay(unsigned long ms
)
112 static inline void debug_calc_bogomips(void)
114 /* This will cause a recalc of bogomips and display the
115 * result. We backup/restore the value to avoid affecting the
116 * core cpufreq framework's own calculation.
118 extern void calibrate_delay(void);
120 unsigned long save_lpj
= loops_per_jiffy
;
122 loops_per_jiffy
= save_lpj
;
124 #endif /* DEBUG_FREQ */
126 /* Switch CPU speed under 750FX CPU control
128 static int cpu_750fx_cpu_speed(int low_speed
)
132 if (low_speed
== 0) {
133 /* ramping up, set voltage first */
134 pmac_call_feature(PMAC_FTR_WRITE_GPIO
, NULL
, voltage_gpio
, 0x05);
135 /* Make sure we sleep for at least 1ms */
138 /* tweak L2 for high voltage */
140 hid2
= mfspr(SPRN_HID2
);
142 mtspr(SPRN_HID2
, hid2
);
146 low_choose_750fx_pll(low_speed
);
148 if (low_speed
== 1) {
149 /* tweak L2 for low voltage */
151 hid2
= mfspr(SPRN_HID2
);
153 mtspr(SPRN_HID2
, hid2
);
156 /* ramping down, set voltage last */
157 pmac_call_feature(PMAC_FTR_WRITE_GPIO
, NULL
, voltage_gpio
, 0x04);
164 static unsigned int cpu_750fx_get_cpu_speed(void)
166 if (mfspr(SPRN_HID1
) & HID1_PS
)
172 /* Switch CPU speed using DFS */
173 static int dfs_set_cpu_speed(int low_speed
)
175 if (low_speed
== 0) {
176 /* ramping up, set voltage first */
177 pmac_call_feature(PMAC_FTR_WRITE_GPIO
, NULL
, voltage_gpio
, 0x05);
178 /* Make sure we sleep for at least 1ms */
184 low_choose_7447a_dfs(low_speed
);
188 if (low_speed
== 1) {
189 /* ramping down, set voltage last */
190 pmac_call_feature(PMAC_FTR_WRITE_GPIO
, NULL
, voltage_gpio
, 0x04);
197 static unsigned int dfs_get_cpu_speed(void)
199 if (mfspr(SPRN_HID1
) & HID1_DFS
)
206 /* Switch CPU speed using slewing GPIOs
208 static int gpios_set_cpu_speed(int low_speed
)
210 int gpio
, timeout
= 0;
212 /* If ramping up, set voltage first */
213 if (low_speed
== 0) {
214 pmac_call_feature(PMAC_FTR_WRITE_GPIO
, NULL
, voltage_gpio
, 0x05);
215 /* Delay is way too big but it's ok, we schedule */
220 gpio
= pmac_call_feature(PMAC_FTR_READ_GPIO
, NULL
, frequency_gpio
, 0);
221 if (low_speed
== ((gpio
& 0x01) == 0))
224 pmac_call_feature(PMAC_FTR_WRITE_GPIO
, NULL
, frequency_gpio
,
225 low_speed
? 0x04 : 0x05);
231 gpio
= pmac_call_feature(PMAC_FTR_READ_GPIO
, NULL
, slew_done_gpio
, 0);
232 } while((gpio
& 0x02) == 0);
234 /* If ramping down, set voltage last */
235 if (low_speed
== 1) {
236 pmac_call_feature(PMAC_FTR_WRITE_GPIO
, NULL
, voltage_gpio
, 0x04);
237 /* Delay is way too big but it's ok, we schedule */
242 debug_calc_bogomips();
248 /* Switch CPU speed under PMU control
250 static int pmu_set_cpu_speed(int low_speed
)
252 struct adb_request req
;
253 unsigned long save_l2cr
;
254 unsigned long save_l3cr
;
255 unsigned int pic_prio
;
261 printk(KERN_DEBUG
"HID1, before: %x\n", mfspr(SPRN_HID1
));
265 /* Disable all interrupt sources on openpic */
266 pic_prio
= mpic_cpu_get_priority();
267 mpic_cpu_set_priority(0xf);
269 /* Make sure the decrementer won't interrupt us */
270 asm volatile("mtdec %0" : : "r" (0x7fffffff));
271 /* Make sure any pending DEC interrupt occurring while we did
272 * the above didn't re-enable the DEC */
274 asm volatile("mtdec %0" : : "r" (0x7fffffff));
276 /* We can now disable MSR_EE */
277 local_irq_save(flags
);
279 /* Giveup the FPU & vec */
282 #ifdef CONFIG_ALTIVEC
283 if (cpu_has_feature(CPU_FTR_ALTIVEC
))
284 enable_kernel_altivec();
285 #endif /* CONFIG_ALTIVEC */
287 /* Save & disable L2 and L3 caches */
288 save_l3cr
= _get_L3CR(); /* (returns -1 if not available) */
289 save_l2cr
= _get_L2CR(); /* (returns -1 if not available) */
291 /* Send the new speed command. My assumption is that this command
292 * will cause PLL_CFG[0..3] to be changed next time CPU goes to sleep
294 pmu_request(&req
, NULL
, 6, PMU_CPU_SPEED
, 'W', 'O', 'O', 'F', low_speed
);
295 while (!req
.complete
)
298 /* Prepare the northbridge for the speed transition */
299 pmac_call_feature(PMAC_FTR_SLEEP_STATE
,NULL
,1,1);
301 /* Call low level code to backup CPU state and recover from
306 /* Restore the northbridge */
307 pmac_call_feature(PMAC_FTR_SLEEP_STATE
,NULL
,1,0);
309 /* Restore L2 cache */
310 if (save_l2cr
!= 0xffffffff && (save_l2cr
& L2CR_L2E
) != 0)
311 _set_L2CR(save_l2cr
);
312 /* Restore L3 cache */
313 if (save_l3cr
!= 0xffffffff && (save_l3cr
& L3CR_L3E
) != 0)
314 _set_L3CR(save_l3cr
);
316 /* Restore userland MMU context */
317 set_context(current
->active_mm
->context
.id
, current
->active_mm
->pgd
);
320 printk(KERN_DEBUG
"HID1, after: %x\n", mfspr(SPRN_HID1
));
323 /* Restore low level PMU operations */
326 /* Restore decrementer */
327 wakeup_decrementer();
329 /* Restore interrupts */
330 mpic_cpu_set_priority(pic_prio
);
332 /* Let interrupts flow again ... */
333 local_irq_restore(flags
);
336 debug_calc_bogomips();
346 static int do_set_cpu_speed(int speed_mode
, int notify
)
348 struct cpufreq_freqs freqs
;
350 static unsigned long prev_l3cr
;
352 freqs
.old
= cur_freq
;
353 freqs
.new = (speed_mode
== CPUFREQ_HIGH
) ? hi_freq
: low_freq
;
354 freqs
.cpu
= smp_processor_id();
356 if (freqs
.old
== freqs
.new)
360 cpufreq_notify_transition(&freqs
, CPUFREQ_PRECHANGE
);
361 if (speed_mode
== CPUFREQ_LOW
&&
362 cpu_has_feature(CPU_FTR_L3CR
)) {
364 if (l3cr
& L3CR_L3E
) {
369 set_speed_proc(speed_mode
== CPUFREQ_LOW
);
370 if (speed_mode
== CPUFREQ_HIGH
&&
371 cpu_has_feature(CPU_FTR_L3CR
)) {
373 if ((prev_l3cr
& L3CR_L3E
) && l3cr
!= prev_l3cr
)
374 _set_L3CR(prev_l3cr
);
377 cpufreq_notify_transition(&freqs
, CPUFREQ_POSTCHANGE
);
378 cur_freq
= (speed_mode
== CPUFREQ_HIGH
) ? hi_freq
: low_freq
;
383 static unsigned int pmac_cpufreq_get_speed(unsigned int cpu
)
388 static int pmac_cpufreq_verify(struct cpufreq_policy
*policy
)
390 return cpufreq_frequency_table_verify(policy
, pmac_cpu_freqs
);
393 static int pmac_cpufreq_target( struct cpufreq_policy
*policy
,
394 unsigned int target_freq
,
395 unsigned int relation
)
397 unsigned int newstate
= 0;
400 if (cpufreq_frequency_table_target(policy
, pmac_cpu_freqs
,
401 target_freq
, relation
, &newstate
))
404 rc
= do_set_cpu_speed(newstate
, 1);
406 ppc_proc_freq
= cur_freq
* 1000ul;
410 static int pmac_cpufreq_cpu_init(struct cpufreq_policy
*policy
)
412 if (policy
->cpu
!= 0)
415 policy
->governor
= CPUFREQ_DEFAULT_GOVERNOR
;
416 policy
->cpuinfo
.transition_latency
= CPUFREQ_ETERNAL
;
417 policy
->cur
= cur_freq
;
419 cpufreq_frequency_table_get_attr(pmac_cpu_freqs
, policy
->cpu
);
420 return cpufreq_frequency_table_cpuinfo(policy
, pmac_cpu_freqs
);
423 static u32
read_gpio(struct device_node
*np
)
425 u32
*reg
= (u32
*)get_property(np
, "reg", NULL
);
430 /* That works for all keylargos but shall be fixed properly
431 * some day... The problem is that it seems we can't rely
432 * on the "reg" property of the GPIO nodes, they are either
433 * relative to the base of KeyLargo or to the base of the
434 * GPIO space, and the device-tree doesn't help.
437 if (offset
< KEYLARGO_GPIO_LEVELS0
)
438 offset
+= KEYLARGO_GPIO_LEVELS0
;
442 static int pmac_cpufreq_suspend(struct cpufreq_policy
*policy
, pm_message_t pmsg
)
444 /* Ok, this could be made a bit smarter, but let's be robust for now. We
445 * always force a speed change to high speed before sleep, to make sure
446 * we have appropriate voltage and/or bus speed for the wakeup process,
447 * and to make sure our loops_per_jiffies are "good enough", that is will
448 * not cause too short delays if we sleep in low speed and wake in high
452 sleep_freq
= cur_freq
;
453 if (cur_freq
== low_freq
&& !is_pmu_based
)
454 do_set_cpu_speed(CPUFREQ_HIGH
, 0);
458 static int pmac_cpufreq_resume(struct cpufreq_policy
*policy
)
460 /* If we resume, first check if we have a get() function */
462 cur_freq
= get_speed_proc();
466 /* We don't, hrm... we don't really know our speed here, best
467 * is that we force a switch to whatever it was, which is
468 * probably high speed due to our suspend() routine
470 do_set_cpu_speed(sleep_freq
== low_freq
?
471 CPUFREQ_LOW
: CPUFREQ_HIGH
, 0);
473 ppc_proc_freq
= cur_freq
* 1000ul;
479 static struct cpufreq_driver pmac_cpufreq_driver
= {
480 .verify
= pmac_cpufreq_verify
,
481 .target
= pmac_cpufreq_target
,
482 .get
= pmac_cpufreq_get_speed
,
483 .init
= pmac_cpufreq_cpu_init
,
484 .suspend
= pmac_cpufreq_suspend
,
485 .resume
= pmac_cpufreq_resume
,
486 .flags
= CPUFREQ_PM_NO_WARN
,
487 .attr
= pmac_cpu_freqs_attr
,
489 .owner
= THIS_MODULE
,
493 static int pmac_cpufreq_init_MacRISC3(struct device_node
*cpunode
)
495 struct device_node
*volt_gpio_np
= of_find_node_by_name(NULL
,
497 struct device_node
*freq_gpio_np
= of_find_node_by_name(NULL
,
499 struct device_node
*slew_done_gpio_np
= of_find_node_by_name(NULL
,
504 * Check to see if it's GPIO driven or PMU only
506 * The way we extract the GPIO address is slightly hackish, but it
507 * works well enough for now. We need to abstract the whole GPIO
508 * stuff sooner or later anyway
512 voltage_gpio
= read_gpio(volt_gpio_np
);
514 frequency_gpio
= read_gpio(freq_gpio_np
);
515 if (slew_done_gpio_np
)
516 slew_done_gpio
= read_gpio(slew_done_gpio_np
);
518 /* If we use the frequency GPIOs, calculate the min/max speeds based
519 * on the bus frequencies
521 if (frequency_gpio
&& slew_done_gpio
) {
525 freqs
= (u32
*)get_property(cpunode
, "bus-frequencies", &lenp
);
527 if (freqs
== NULL
|| lenp
!= 2) {
528 printk(KERN_ERR
"cpufreq: bus-frequencies incorrect or missing\n");
531 ratio
= (u32
*)get_property(cpunode
, "processor-to-bus-ratio*2", NULL
);
533 printk(KERN_ERR
"cpufreq: processor-to-bus-ratio*2 missing\n");
537 /* Get the min/max bus frequencies */
538 low_freq
= min(freqs
[0], freqs
[1]);
539 hi_freq
= max(freqs
[0], freqs
[1]);
541 /* Grrrr.. It _seems_ that the device-tree is lying on the low bus
542 * frequency, it claims it to be around 84Mhz on some models while
543 * it appears to be approx. 101Mhz on all. Let's hack around here...
544 * fortunately, we don't need to be too precise
546 if (low_freq
< 98000000)
547 low_freq
= 101000000;
549 /* Convert those to CPU core clocks */
550 low_freq
= (low_freq
* (*ratio
)) / 2000;
551 hi_freq
= (hi_freq
* (*ratio
)) / 2000;
553 /* Now we get the frequencies, we read the GPIO to see what is out current
556 rc
= pmac_call_feature(PMAC_FTR_READ_GPIO
, NULL
, frequency_gpio
, 0);
557 cur_freq
= (rc
& 0x01) ? hi_freq
: low_freq
;
559 set_speed_proc
= gpios_set_cpu_speed
;
563 /* If we use the PMU, look for the min & max frequencies in the
566 value
= (u32
*)get_property(cpunode
, "min-clock-frequency", NULL
);
569 low_freq
= (*value
) / 1000;
570 /* The PowerBook G4 12" (PowerBook6,1) has an error in the device-tree
572 if (low_freq
< 100000)
575 value
= (u32
*)get_property(cpunode
, "max-clock-frequency", NULL
);
578 hi_freq
= (*value
) / 1000;
579 set_speed_proc
= pmu_set_cpu_speed
;
585 static int pmac_cpufreq_init_7447A(struct device_node
*cpunode
)
587 struct device_node
*volt_gpio_np
;
589 if (get_property(cpunode
, "dynamic-power-step", NULL
) == NULL
)
592 volt_gpio_np
= of_find_node_by_name(NULL
, "cpu-vcore-select");
594 voltage_gpio
= read_gpio(volt_gpio_np
);
596 printk(KERN_ERR
"cpufreq: missing cpu-vcore-select gpio\n");
600 /* OF only reports the high frequency */
602 low_freq
= cur_freq
/2;
604 /* Read actual frequency from CPU */
605 cur_freq
= dfs_get_cpu_speed();
606 set_speed_proc
= dfs_set_cpu_speed
;
607 get_speed_proc
= dfs_get_cpu_speed
;
612 static int pmac_cpufreq_init_750FX(struct device_node
*cpunode
)
614 struct device_node
*volt_gpio_np
;
617 if (get_property(cpunode
, "dynamic-power-step", NULL
) == NULL
)
621 value
= (u32
*)get_property(cpunode
, "reduced-clock-frequency", NULL
);
624 low_freq
= (*value
) / 1000;
626 volt_gpio_np
= of_find_node_by_name(NULL
, "cpu-vcore-select");
628 voltage_gpio
= read_gpio(volt_gpio_np
);
630 pvr
= mfspr(SPRN_PVR
);
631 has_cpu_l2lve
= !((pvr
& 0xf00) == 0x100);
633 set_speed_proc
= cpu_750fx_cpu_speed
;
634 get_speed_proc
= cpu_750fx_get_cpu_speed
;
635 cur_freq
= cpu_750fx_get_cpu_speed();
640 /* Currently, we support the following machines:
642 * - Titanium PowerBook 1Ghz (PMU based, 667Mhz & 1Ghz)
643 * - Titanium PowerBook 800 (PMU based, 667Mhz & 800Mhz)
644 * - Titanium PowerBook 400 (PMU based, 300Mhz & 400Mhz)
645 * - Titanium PowerBook 500 (PMU based, 300Mhz & 500Mhz)
646 * - iBook2 500/600 (PMU based, 400Mhz & 500/600Mhz)
647 * - iBook2 700 (CPU based, 400Mhz & 700Mhz, support low voltage)
648 * - Recent MacRISC3 laptops
649 * - All new machines with 7447A CPUs
651 static int __init
pmac_cpufreq_setup(void)
653 struct device_node
*cpunode
;
656 if (strstr(cmd_line
, "nocpufreq"))
659 /* Assume only one CPU */
660 cpunode
= find_type_devices("cpu");
664 /* Get current cpu clock freq */
665 value
= (u32
*)get_property(cpunode
, "clock-frequency", NULL
);
668 cur_freq
= (*value
) / 1000;
670 /* Check for 7447A based MacRISC3 */
671 if (machine_is_compatible("MacRISC3") &&
672 get_property(cpunode
, "dynamic-power-step", NULL
) &&
673 PVR_VER(mfspr(SPRN_PVR
)) == 0x8003) {
674 pmac_cpufreq_init_7447A(cpunode
);
675 /* Check for other MacRISC3 machines */
676 } else if (machine_is_compatible("PowerBook3,4") ||
677 machine_is_compatible("PowerBook3,5") ||
678 machine_is_compatible("MacRISC3")) {
679 pmac_cpufreq_init_MacRISC3(cpunode
);
680 /* Else check for iBook2 500/600 */
681 } else if (machine_is_compatible("PowerBook4,1")) {
684 set_speed_proc
= pmu_set_cpu_speed
;
687 /* Else check for TiPb 550 */
688 else if (machine_is_compatible("PowerBook3,3") && cur_freq
== 550000) {
691 set_speed_proc
= pmu_set_cpu_speed
;
694 /* Else check for TiPb 400 & 500 */
695 else if (machine_is_compatible("PowerBook3,2")) {
696 /* We only know about the 400 MHz and the 500Mhz model
697 * they both have 300 MHz as low frequency
699 if (cur_freq
< 350000 || cur_freq
> 550000)
703 set_speed_proc
= pmu_set_cpu_speed
;
706 /* Else check for 750FX */
707 else if (PVR_VER(mfspr(SPRN_PVR
)) == 0x7000)
708 pmac_cpufreq_init_750FX(cpunode
);
710 if (set_speed_proc
== NULL
)
713 pmac_cpu_freqs
[CPUFREQ_LOW
].frequency
= low_freq
;
714 pmac_cpu_freqs
[CPUFREQ_HIGH
].frequency
= hi_freq
;
715 ppc_proc_freq
= cur_freq
* 1000ul;
717 printk(KERN_INFO
"Registering PowerMac CPU frequency driver\n");
718 printk(KERN_INFO
"Low: %d Mhz, High: %d Mhz, Boot: %d Mhz\n",
719 low_freq
/1000, hi_freq
/1000, cur_freq
/1000);
721 return cpufreq_register_driver(&pmac_cpufreq_driver
);
724 module_init(pmac_cpufreq_setup
);