1 // SPDX-License-Identifier: GPL-2.0-only
3 * Copyright (C) 2002 - 2005 Benjamin Herrenschmidt <benh@kernel.crashing.org>
4 * Copyright (C) 2004 John Steele Scott <toojays@toojays.net>
6 * TODO: Need a big cleanup here. Basically, we need to have different
7 * cpufreq_driver structures for the different type of HW instead of the
8 * current mess. We also need to better deal with the detection of the
12 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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/adb.h>
21 #include <linux/pmu.h>
22 #include <linux/cpufreq.h>
23 #include <linux/init.h>
24 #include <linux/device.h>
25 #include <linux/hardirq.h>
27 #include <linux/of_address.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, 0, CPUFREQ_TABLE_END
},
88 static inline void local_delay(unsigned long ms
)
97 static inline void debug_calc_bogomips(void)
99 /* This will cause a recalc of bogomips and display the
100 * result. We backup/restore the value to avoid affecting the
101 * core cpufreq framework's own calculation.
103 unsigned long save_lpj
= loops_per_jiffy
;
105 loops_per_jiffy
= save_lpj
;
107 #endif /* DEBUG_FREQ */
109 /* Switch CPU speed under 750FX CPU control
111 static int cpu_750fx_cpu_speed(int low_speed
)
115 if (low_speed
== 0) {
116 /* ramping up, set voltage first */
117 pmac_call_feature(PMAC_FTR_WRITE_GPIO
, NULL
, voltage_gpio
, 0x05);
118 /* Make sure we sleep for at least 1ms */
121 /* tweak L2 for high voltage */
123 hid2
= mfspr(SPRN_HID2_750FX
);
125 mtspr(SPRN_HID2_750FX
, hid2
);
128 #ifdef CONFIG_PPC_BOOK3S_32
129 low_choose_750fx_pll(low_speed
);
131 if (low_speed
== 1) {
132 /* tweak L2 for low voltage */
134 hid2
= mfspr(SPRN_HID2_750FX
);
136 mtspr(SPRN_HID2_750FX
, hid2
);
139 /* ramping down, set voltage last */
140 pmac_call_feature(PMAC_FTR_WRITE_GPIO
, NULL
, voltage_gpio
, 0x04);
147 static unsigned int cpu_750fx_get_cpu_speed(void)
149 if (mfspr(SPRN_HID1
) & HID1_PS
)
155 /* Switch CPU speed using DFS */
156 static int dfs_set_cpu_speed(int low_speed
)
158 if (low_speed
== 0) {
159 /* ramping up, set voltage first */
160 pmac_call_feature(PMAC_FTR_WRITE_GPIO
, NULL
, voltage_gpio
, 0x05);
161 /* Make sure we sleep for at least 1ms */
166 #ifdef CONFIG_PPC_BOOK3S_32
167 low_choose_7447a_dfs(low_speed
);
171 if (low_speed
== 1) {
172 /* ramping down, set voltage last */
173 pmac_call_feature(PMAC_FTR_WRITE_GPIO
, NULL
, voltage_gpio
, 0x04);
180 static unsigned int dfs_get_cpu_speed(void)
182 if (mfspr(SPRN_HID1
) & HID1_DFS
)
189 /* Switch CPU speed using slewing GPIOs
191 static int gpios_set_cpu_speed(int low_speed
)
193 int gpio
, timeout
= 0;
195 /* If ramping up, set voltage first */
196 if (low_speed
== 0) {
197 pmac_call_feature(PMAC_FTR_WRITE_GPIO
, NULL
, voltage_gpio
, 0x05);
198 /* Delay is way too big but it's ok, we schedule */
203 gpio
= pmac_call_feature(PMAC_FTR_READ_GPIO
, NULL
, frequency_gpio
, 0);
204 if (low_speed
== ((gpio
& 0x01) == 0))
207 pmac_call_feature(PMAC_FTR_WRITE_GPIO
, NULL
, frequency_gpio
,
208 low_speed
? 0x04 : 0x05);
214 gpio
= pmac_call_feature(PMAC_FTR_READ_GPIO
, NULL
, slew_done_gpio
, 0);
215 } while((gpio
& 0x02) == 0);
217 /* If ramping down, set voltage last */
218 if (low_speed
== 1) {
219 pmac_call_feature(PMAC_FTR_WRITE_GPIO
, NULL
, voltage_gpio
, 0x04);
220 /* Delay is way too big but it's ok, we schedule */
225 debug_calc_bogomips();
231 /* Switch CPU speed under PMU control
233 static int pmu_set_cpu_speed(int low_speed
)
235 struct adb_request req
;
236 unsigned long save_l2cr
;
237 unsigned long save_l3cr
;
238 unsigned int pic_prio
;
244 printk(KERN_DEBUG
"HID1, before: %x\n", mfspr(SPRN_HID1
));
248 /* Disable all interrupt sources on openpic */
249 pic_prio
= mpic_cpu_get_priority();
250 mpic_cpu_set_priority(0xf);
252 /* Make sure the decrementer won't interrupt us */
253 asm volatile("mtdec %0" : : "r" (0x7fffffff));
254 /* Make sure any pending DEC interrupt occurring while we did
255 * the above didn't re-enable the DEC */
257 asm volatile("mtdec %0" : : "r" (0x7fffffff));
259 /* We can now disable MSR_EE */
260 local_irq_save(flags
);
262 /* Giveup the FPU & vec */
265 #ifdef CONFIG_ALTIVEC
266 if (cpu_has_feature(CPU_FTR_ALTIVEC
))
267 enable_kernel_altivec();
268 #endif /* CONFIG_ALTIVEC */
270 /* Save & disable L2 and L3 caches */
271 save_l3cr
= _get_L3CR(); /* (returns -1 if not available) */
272 save_l2cr
= _get_L2CR(); /* (returns -1 if not available) */
274 /* Send the new speed command. My assumption is that this command
275 * will cause PLL_CFG[0..3] to be changed next time CPU goes to sleep
277 pmu_request(&req
, NULL
, 6, PMU_CPU_SPEED
, 'W', 'O', 'O', 'F', low_speed
);
278 while (!req
.complete
)
281 /* Prepare the northbridge for the speed transition */
282 pmac_call_feature(PMAC_FTR_SLEEP_STATE
,NULL
,1,1);
284 /* Call low level code to backup CPU state and recover from
289 /* Restore the northbridge */
290 pmac_call_feature(PMAC_FTR_SLEEP_STATE
,NULL
,1,0);
292 /* Restore L2 cache */
293 if (save_l2cr
!= 0xffffffff && (save_l2cr
& L2CR_L2E
) != 0)
294 _set_L2CR(save_l2cr
);
295 /* Restore L3 cache */
296 if (save_l3cr
!= 0xffffffff && (save_l3cr
& L3CR_L3E
) != 0)
297 _set_L3CR(save_l3cr
);
299 /* Restore userland MMU context */
300 switch_mmu_context(NULL
, current
->active_mm
, NULL
);
303 printk(KERN_DEBUG
"HID1, after: %x\n", mfspr(SPRN_HID1
));
306 /* Restore low level PMU operations */
310 * Restore decrementer; we'll take a decrementer interrupt
311 * as soon as interrupts are re-enabled and the generic
312 * clockevents code will reprogram it with the right value.
316 /* Restore interrupts */
317 mpic_cpu_set_priority(pic_prio
);
319 /* Let interrupts flow again ... */
320 local_irq_restore(flags
);
323 debug_calc_bogomips();
333 static int do_set_cpu_speed(struct cpufreq_policy
*policy
, int speed_mode
)
336 static unsigned long prev_l3cr
;
338 if (speed_mode
== CPUFREQ_LOW
&&
339 cpu_has_feature(CPU_FTR_L3CR
)) {
341 if (l3cr
& L3CR_L3E
) {
346 set_speed_proc(speed_mode
== CPUFREQ_LOW
);
347 if (speed_mode
== CPUFREQ_HIGH
&&
348 cpu_has_feature(CPU_FTR_L3CR
)) {
350 if ((prev_l3cr
& L3CR_L3E
) && l3cr
!= prev_l3cr
)
351 _set_L3CR(prev_l3cr
);
353 cur_freq
= (speed_mode
== CPUFREQ_HIGH
) ? hi_freq
: low_freq
;
358 static unsigned int pmac_cpufreq_get_speed(unsigned int cpu
)
363 static int pmac_cpufreq_target( struct cpufreq_policy
*policy
,
368 rc
= do_set_cpu_speed(policy
, index
);
370 ppc_proc_freq
= cur_freq
* 1000ul;
374 static int pmac_cpufreq_cpu_init(struct cpufreq_policy
*policy
)
376 cpufreq_generic_init(policy
, pmac_cpu_freqs
, transition_latency
);
380 static u32
read_gpio(struct device_node
*np
)
384 if (of_property_read_reg(np
, 0, &offset
, NULL
) < 0)
386 /* That works for all keylargos but shall be fixed properly
387 * some day... The problem is that it seems we can't rely
388 * on the "reg" property of the GPIO nodes, they are either
389 * relative to the base of KeyLargo or to the base of the
390 * GPIO space, and the device-tree doesn't help.
392 if (offset
< KEYLARGO_GPIO_LEVELS0
)
393 offset
+= KEYLARGO_GPIO_LEVELS0
;
397 static int pmac_cpufreq_suspend(struct cpufreq_policy
*policy
)
399 /* Ok, this could be made a bit smarter, but let's be robust for now. We
400 * always force a speed change to high speed before sleep, to make sure
401 * we have appropriate voltage and/or bus speed for the wakeup process,
402 * and to make sure our loops_per_jiffies are "good enough", that is will
403 * not cause too short delays if we sleep in low speed and wake in high
407 sleep_freq
= cur_freq
;
408 if (cur_freq
== low_freq
&& !is_pmu_based
)
409 do_set_cpu_speed(policy
, CPUFREQ_HIGH
);
413 static int pmac_cpufreq_resume(struct cpufreq_policy
*policy
)
415 /* If we resume, first check if we have a get() function */
417 cur_freq
= get_speed_proc();
421 /* We don't, hrm... we don't really know our speed here, best
422 * is that we force a switch to whatever it was, which is
423 * probably high speed due to our suspend() routine
425 do_set_cpu_speed(policy
, sleep_freq
== low_freq
?
426 CPUFREQ_LOW
: CPUFREQ_HIGH
);
428 ppc_proc_freq
= cur_freq
* 1000ul;
434 static struct cpufreq_driver pmac_cpufreq_driver
= {
435 .verify
= cpufreq_generic_frequency_table_verify
,
436 .target_index
= pmac_cpufreq_target
,
437 .get
= pmac_cpufreq_get_speed
,
438 .init
= pmac_cpufreq_cpu_init
,
439 .suspend
= pmac_cpufreq_suspend
,
440 .resume
= pmac_cpufreq_resume
,
441 .flags
= CPUFREQ_NO_AUTO_DYNAMIC_SWITCHING
,
442 .attr
= cpufreq_generic_attr
,
447 static int pmac_cpufreq_init_MacRISC3(struct device_node
*cpunode
)
449 struct device_node
*volt_gpio_np
= of_find_node_by_name(NULL
,
451 struct device_node
*freq_gpio_np
= of_find_node_by_name(NULL
,
453 struct device_node
*slew_done_gpio_np
= of_find_node_by_name(NULL
,
458 * Check to see if it's GPIO driven or PMU only
460 * The way we extract the GPIO address is slightly hackish, but it
461 * works well enough for now. We need to abstract the whole GPIO
462 * stuff sooner or later anyway
466 voltage_gpio
= read_gpio(volt_gpio_np
);
468 frequency_gpio
= read_gpio(freq_gpio_np
);
469 if (slew_done_gpio_np
)
470 slew_done_gpio
= read_gpio(slew_done_gpio_np
);
472 of_node_put(volt_gpio_np
);
473 of_node_put(freq_gpio_np
);
474 of_node_put(slew_done_gpio_np
);
476 /* If we use the frequency GPIOs, calculate the min/max speeds based
477 * on the bus frequencies
479 if (frequency_gpio
&& slew_done_gpio
) {
481 const u32
*freqs
, *ratio
;
483 freqs
= of_get_property(cpunode
, "bus-frequencies", &lenp
);
485 if (freqs
== NULL
|| lenp
!= 2) {
486 pr_err("bus-frequencies incorrect or missing\n");
489 ratio
= of_get_property(cpunode
, "processor-to-bus-ratio*2",
492 pr_err("processor-to-bus-ratio*2 missing\n");
496 /* Get the min/max bus frequencies */
497 low_freq
= min(freqs
[0], freqs
[1]);
498 hi_freq
= max(freqs
[0], freqs
[1]);
500 /* Grrrr.. It _seems_ that the device-tree is lying on the low bus
501 * frequency, it claims it to be around 84Mhz on some models while
502 * it appears to be approx. 101Mhz on all. Let's hack around here...
503 * fortunately, we don't need to be too precise
505 if (low_freq
< 98000000)
506 low_freq
= 101000000;
508 /* Convert those to CPU core clocks */
509 low_freq
= (low_freq
* (*ratio
)) / 2000;
510 hi_freq
= (hi_freq
* (*ratio
)) / 2000;
512 /* Now we get the frequencies, we read the GPIO to see what is out current
515 rc
= pmac_call_feature(PMAC_FTR_READ_GPIO
, NULL
, frequency_gpio
, 0);
516 cur_freq
= (rc
& 0x01) ? hi_freq
: low_freq
;
518 set_speed_proc
= gpios_set_cpu_speed
;
522 /* If we use the PMU, look for the min & max frequencies in the
525 value
= of_get_property(cpunode
, "min-clock-frequency", NULL
);
528 low_freq
= (*value
) / 1000;
529 /* The PowerBook G4 12" (PowerBook6,1) has an error in the device-tree
531 if (low_freq
< 100000)
534 value
= of_get_property(cpunode
, "max-clock-frequency", NULL
);
537 hi_freq
= (*value
) / 1000;
538 set_speed_proc
= pmu_set_cpu_speed
;
544 static int pmac_cpufreq_init_7447A(struct device_node
*cpunode
)
546 struct device_node
*volt_gpio_np
;
548 if (!of_property_read_bool(cpunode
, "dynamic-power-step"))
551 volt_gpio_np
= of_find_node_by_name(NULL
, "cpu-vcore-select");
553 voltage_gpio
= read_gpio(volt_gpio_np
);
554 of_node_put(volt_gpio_np
);
556 pr_err("missing cpu-vcore-select gpio\n");
560 /* OF only reports the high frequency */
562 low_freq
= cur_freq
/2;
564 /* Read actual frequency from CPU */
565 cur_freq
= dfs_get_cpu_speed();
566 set_speed_proc
= dfs_set_cpu_speed
;
567 get_speed_proc
= dfs_get_cpu_speed
;
572 static int pmac_cpufreq_init_750FX(struct device_node
*cpunode
)
574 struct device_node
*volt_gpio_np
;
578 if (!of_property_read_bool(cpunode
, "dynamic-power-step"))
582 value
= of_get_property(cpunode
, "reduced-clock-frequency", NULL
);
585 low_freq
= (*value
) / 1000;
587 volt_gpio_np
= of_find_node_by_name(NULL
, "cpu-vcore-select");
589 voltage_gpio
= read_gpio(volt_gpio_np
);
591 of_node_put(volt_gpio_np
);
592 pvr
= mfspr(SPRN_PVR
);
593 has_cpu_l2lve
= !((pvr
& 0xf00) == 0x100);
595 set_speed_proc
= cpu_750fx_cpu_speed
;
596 get_speed_proc
= cpu_750fx_get_cpu_speed
;
597 cur_freq
= cpu_750fx_get_cpu_speed();
602 /* Currently, we support the following machines:
604 * - Titanium PowerBook 1Ghz (PMU based, 667Mhz & 1Ghz)
605 * - Titanium PowerBook 800 (PMU based, 667Mhz & 800Mhz)
606 * - Titanium PowerBook 400 (PMU based, 300Mhz & 400Mhz)
607 * - Titanium PowerBook 500 (PMU based, 300Mhz & 500Mhz)
608 * - iBook2 500/600 (PMU based, 400Mhz & 500/600Mhz)
609 * - iBook2 700 (CPU based, 400Mhz & 700Mhz, support low voltage)
610 * - Recent MacRISC3 laptops
611 * - All new machines with 7447A CPUs
613 static int __init
pmac_cpufreq_setup(void)
615 struct device_node
*cpunode
;
618 if (strstr(boot_command_line
, "nocpufreq"))
621 /* Get first CPU node */
622 cpunode
= of_cpu_device_node_get(0);
626 /* Get current cpu clock freq */
627 value
= of_get_property(cpunode
, "clock-frequency", NULL
);
630 cur_freq
= (*value
) / 1000;
632 /* Check for 7447A based MacRISC3 */
633 if (of_machine_is_compatible("MacRISC3") &&
634 of_property_read_bool(cpunode
, "dynamic-power-step") &&
635 PVR_VER(mfspr(SPRN_PVR
)) == 0x8003) {
636 pmac_cpufreq_init_7447A(cpunode
);
638 /* Allow dynamic switching */
639 transition_latency
= 8000000;
640 pmac_cpufreq_driver
.flags
&= ~CPUFREQ_NO_AUTO_DYNAMIC_SWITCHING
;
641 /* Check for other MacRISC3 machines */
642 } else if (of_machine_is_compatible("PowerBook3,4") ||
643 of_machine_is_compatible("PowerBook3,5") ||
644 of_machine_is_compatible("MacRISC3")) {
645 pmac_cpufreq_init_MacRISC3(cpunode
);
646 /* Else check for iBook2 500/600 */
647 } else if (of_machine_is_compatible("PowerBook4,1")) {
650 set_speed_proc
= pmu_set_cpu_speed
;
653 /* Else check for TiPb 550 */
654 else if (of_machine_is_compatible("PowerBook3,3") && cur_freq
== 550000) {
657 set_speed_proc
= pmu_set_cpu_speed
;
660 /* Else check for TiPb 400 & 500 */
661 else if (of_machine_is_compatible("PowerBook3,2")) {
662 /* We only know about the 400 MHz and the 500Mhz model
663 * they both have 300 MHz as low frequency
665 if (cur_freq
< 350000 || cur_freq
> 550000)
669 set_speed_proc
= pmu_set_cpu_speed
;
672 /* Else check for 750FX */
673 else if (PVR_VER(mfspr(SPRN_PVR
)) == 0x7000)
674 pmac_cpufreq_init_750FX(cpunode
);
676 of_node_put(cpunode
);
677 if (set_speed_proc
== NULL
)
680 pmac_cpu_freqs
[CPUFREQ_LOW
].frequency
= low_freq
;
681 pmac_cpu_freqs
[CPUFREQ_HIGH
].frequency
= hi_freq
;
682 ppc_proc_freq
= cur_freq
* 1000ul;
684 pr_info("Registering PowerMac CPU frequency driver\n");
685 pr_info("Low: %d Mhz, High: %d Mhz, Boot: %d Mhz\n",
686 low_freq
/1000, hi_freq
/1000, cur_freq
/1000);
688 return cpufreq_register_driver(&pmac_cpufreq_driver
);
691 module_init(pmac_cpufreq_setup
);