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>
36 #include <asm/system.h>
38 #include <asm/keylargo.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;
60 * Different models uses different mechanisms to switch the frequency
62 static int (*set_speed_proc)(int low_speed);
63 static unsigned int (*get_speed_proc)(void);
66 * Some definitions used by the various speedprocs
68 static u32 voltage_gpio;
69 static u32 frequency_gpio;
70 static u32 slew_done_gpio;
71 static int no_schedule;
72 static int has_cpu_l2lve;
73 static int is_pmu_based;
75 /* There are only two frequency states for each processor. Values
76 * are in kHz for the time being.
78 #define CPUFREQ_HIGH 0
81 static struct cpufreq_frequency_table pmac_cpu_freqs[] = {
84 {0, CPUFREQ_TABLE_END},
87 static struct freq_attr* pmac_cpu_freqs_attr[] = {
88 &cpufreq_freq_attr_scaling_available_freqs,
92 static inline void local_delay(unsigned long ms)
101 static inline void debug_calc_bogomips(void)
103 /* This will cause a recalc of bogomips and display the
104 * result. We backup/restore the value to avoid affecting the
105 * core cpufreq framework's own calculation.
107 unsigned long save_lpj = loops_per_jiffy;
109 loops_per_jiffy = save_lpj;
111 #endif /* DEBUG_FREQ */
113 /* Switch CPU speed under 750FX CPU control
115 static int cpu_750fx_cpu_speed(int low_speed)
119 if (low_speed == 0) {
120 /* ramping up, set voltage first */
121 pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, voltage_gpio, 0x05);
122 /* Make sure we sleep for at least 1ms */
125 /* tweak L2 for high voltage */
127 hid2 = mfspr(SPRN_HID2);
129 mtspr(SPRN_HID2, hid2);
133 low_choose_750fx_pll(low_speed);
135 if (low_speed == 1) {
136 /* tweak L2 for low voltage */
138 hid2 = mfspr(SPRN_HID2);
140 mtspr(SPRN_HID2, hid2);
143 /* ramping down, set voltage last */
144 pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, voltage_gpio, 0x04);
151 static unsigned int cpu_750fx_get_cpu_speed(void)
153 if (mfspr(SPRN_HID1) & HID1_PS)
159 /* Switch CPU speed using DFS */
160 static int dfs_set_cpu_speed(int low_speed)
162 if (low_speed == 0) {
163 /* ramping up, set voltage first */
164 pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, voltage_gpio, 0x05);
165 /* Make sure we sleep for at least 1ms */
171 low_choose_7447a_dfs(low_speed);
175 if (low_speed == 1) {
176 /* ramping down, set voltage last */
177 pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, voltage_gpio, 0x04);
184 static unsigned int dfs_get_cpu_speed(void)
186 if (mfspr(SPRN_HID1) & HID1_DFS)
193 /* Switch CPU speed using slewing GPIOs
195 static int gpios_set_cpu_speed(int low_speed)
197 int gpio, timeout = 0;
199 /* If ramping up, set voltage first */
200 if (low_speed == 0) {
201 pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, voltage_gpio, 0x05);
202 /* Delay is way too big but it's ok, we schedule */
207 gpio = pmac_call_feature(PMAC_FTR_READ_GPIO, NULL, frequency_gpio, 0);
208 if (low_speed == ((gpio & 0x01) == 0))
211 pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, frequency_gpio,
212 low_speed ? 0x04 : 0x05);
218 gpio = pmac_call_feature(PMAC_FTR_READ_GPIO, NULL, slew_done_gpio, 0);
219 } while((gpio & 0x02) == 0);
221 /* If ramping down, set voltage last */
222 if (low_speed == 1) {
223 pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, voltage_gpio, 0x04);
224 /* Delay is way too big but it's ok, we schedule */
229 debug_calc_bogomips();
235 /* Switch CPU speed under PMU control
237 static int pmu_set_cpu_speed(int low_speed)
239 struct adb_request req;
240 unsigned long save_l2cr;
241 unsigned long save_l3cr;
242 unsigned int pic_prio;
248 printk(KERN_DEBUG "HID1, before: %x\n", mfspr(SPRN_HID1));
252 /* Disable all interrupt sources on openpic */
253 pic_prio = mpic_cpu_get_priority();
254 mpic_cpu_set_priority(0xf);
256 /* Make sure the decrementer won't interrupt us */
257 asm volatile("mtdec %0" : : "r" (0x7fffffff));
258 /* Make sure any pending DEC interrupt occurring while we did
259 * the above didn't re-enable the DEC */
261 asm volatile("mtdec %0" : : "r" (0x7fffffff));
263 /* We can now disable MSR_EE */
264 local_irq_save(flags);
266 /* Giveup the FPU & vec */
269 #ifdef CONFIG_ALTIVEC
270 if (cpu_has_feature(CPU_FTR_ALTIVEC))
271 enable_kernel_altivec();
272 #endif /* CONFIG_ALTIVEC */
274 /* Save & disable L2 and L3 caches */
275 save_l3cr = _get_L3CR(); /* (returns -1 if not available) */
276 save_l2cr = _get_L2CR(); /* (returns -1 if not available) */
278 /* Send the new speed command. My assumption is that this command
279 * will cause PLL_CFG[0..3] to be changed next time CPU goes to sleep
281 pmu_request(&req, NULL, 6, PMU_CPU_SPEED, 'W', 'O', 'O', 'F', low_speed);
282 while (!req.complete)
285 /* Prepare the northbridge for the speed transition */
286 pmac_call_feature(PMAC_FTR_SLEEP_STATE,NULL,1,1);
288 /* Call low level code to backup CPU state and recover from
293 /* Restore the northbridge */
294 pmac_call_feature(PMAC_FTR_SLEEP_STATE,NULL,1,0);
296 /* Restore L2 cache */
297 if (save_l2cr != 0xffffffff && (save_l2cr & L2CR_L2E) != 0)
298 _set_L2CR(save_l2cr);
299 /* Restore L3 cache */
300 if (save_l3cr != 0xffffffff && (save_l3cr & L3CR_L3E) != 0)
301 _set_L3CR(save_l3cr);
303 /* Restore userland MMU context */
304 switch_mmu_context(NULL, current->active_mm);
307 printk(KERN_DEBUG "HID1, after: %x\n", mfspr(SPRN_HID1));
310 /* Restore low level PMU operations */
314 * Restore decrementer; we'll take a decrementer interrupt
315 * as soon as interrupts are re-enabled and the generic
316 * clockevents code will reprogram it with the right value.
320 /* Restore interrupts */
321 mpic_cpu_set_priority(pic_prio);
323 /* Let interrupts flow again ... */
324 local_irq_restore(flags);
327 debug_calc_bogomips();
337 static int do_set_cpu_speed(int speed_mode, int notify)
339 struct cpufreq_freqs freqs;
341 static unsigned long prev_l3cr;
343 freqs.old = cur_freq;
344 freqs.new = (speed_mode == CPUFREQ_HIGH) ? hi_freq : low_freq;
345 freqs.cpu = smp_processor_id();
347 if (freqs.old == freqs.new)
351 cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
352 if (speed_mode == CPUFREQ_LOW &&
353 cpu_has_feature(CPU_FTR_L3CR)) {
355 if (l3cr & L3CR_L3E) {
360 set_speed_proc(speed_mode == CPUFREQ_LOW);
361 if (speed_mode == CPUFREQ_HIGH &&
362 cpu_has_feature(CPU_FTR_L3CR)) {
364 if ((prev_l3cr & L3CR_L3E) && l3cr != prev_l3cr)
365 _set_L3CR(prev_l3cr);
368 cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
369 cur_freq = (speed_mode == CPUFREQ_HIGH) ? hi_freq : low_freq;
374 static unsigned int pmac_cpufreq_get_speed(unsigned int cpu)
379 static int pmac_cpufreq_verify(struct cpufreq_policy *policy)
381 return cpufreq_frequency_table_verify(policy, pmac_cpu_freqs);
384 static int pmac_cpufreq_target( struct cpufreq_policy *policy,
385 unsigned int target_freq,
386 unsigned int relation)
388 unsigned int newstate = 0;
391 if (cpufreq_frequency_table_target(policy, pmac_cpu_freqs,
392 target_freq, relation, &newstate))
395 rc = do_set_cpu_speed(newstate, 1);
397 ppc_proc_freq = cur_freq * 1000ul;
401 static int pmac_cpufreq_cpu_init(struct cpufreq_policy *policy)
403 if (policy->cpu != 0)
406 policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL;
407 policy->cur = cur_freq;
409 cpufreq_frequency_table_get_attr(pmac_cpu_freqs, policy->cpu);
410 return cpufreq_frequency_table_cpuinfo(policy, pmac_cpu_freqs);
413 static u32 read_gpio(struct device_node *np)
415 const u32 *reg = of_get_property(np, "reg", NULL);
420 /* That works for all keylargos but shall be fixed properly
421 * some day... The problem is that it seems we can't rely
422 * on the "reg" property of the GPIO nodes, they are either
423 * relative to the base of KeyLargo or to the base of the
424 * GPIO space, and the device-tree doesn't help.
427 if (offset < KEYLARGO_GPIO_LEVELS0)
428 offset += KEYLARGO_GPIO_LEVELS0;
432 static int pmac_cpufreq_suspend(struct cpufreq_policy *policy)
434 /* Ok, this could be made a bit smarter, but let's be robust for now. We
435 * always force a speed change to high speed before sleep, to make sure
436 * we have appropriate voltage and/or bus speed for the wakeup process,
437 * and to make sure our loops_per_jiffies are "good enough", that is will
438 * not cause too short delays if we sleep in low speed and wake in high
442 sleep_freq = cur_freq;
443 if (cur_freq == low_freq && !is_pmu_based)
444 do_set_cpu_speed(CPUFREQ_HIGH, 0);
448 static int pmac_cpufreq_resume(struct cpufreq_policy *policy)
450 /* If we resume, first check if we have a get() function */
452 cur_freq = get_speed_proc();
456 /* We don't, hrm... we don't really know our speed here, best
457 * is that we force a switch to whatever it was, which is
458 * probably high speed due to our suspend() routine
460 do_set_cpu_speed(sleep_freq == low_freq ?
461 CPUFREQ_LOW : CPUFREQ_HIGH, 0);
463 ppc_proc_freq = cur_freq * 1000ul;
469 static struct cpufreq_driver pmac_cpufreq_driver = {
470 .verify = pmac_cpufreq_verify,
471 .target = pmac_cpufreq_target,
472 .get = pmac_cpufreq_get_speed,
473 .init = pmac_cpufreq_cpu_init,
474 .suspend = pmac_cpufreq_suspend,
475 .resume = pmac_cpufreq_resume,
476 .flags = CPUFREQ_PM_NO_WARN,
477 .attr = pmac_cpu_freqs_attr,
479 .owner = THIS_MODULE,
483 static int pmac_cpufreq_init_MacRISC3(struct device_node *cpunode)
485 struct device_node *volt_gpio_np = of_find_node_by_name(NULL,
487 struct device_node *freq_gpio_np = of_find_node_by_name(NULL,
489 struct device_node *slew_done_gpio_np = of_find_node_by_name(NULL,
494 * Check to see if it's GPIO driven or PMU only
496 * The way we extract the GPIO address is slightly hackish, but it
497 * works well enough for now. We need to abstract the whole GPIO
498 * stuff sooner or later anyway
502 voltage_gpio = read_gpio(volt_gpio_np);
504 frequency_gpio = read_gpio(freq_gpio_np);
505 if (slew_done_gpio_np)
506 slew_done_gpio = read_gpio(slew_done_gpio_np);
508 /* If we use the frequency GPIOs, calculate the min/max speeds based
509 * on the bus frequencies
511 if (frequency_gpio && slew_done_gpio) {
513 const u32 *freqs, *ratio;
515 freqs = of_get_property(cpunode, "bus-frequencies", &lenp);
517 if (freqs == NULL || lenp != 2) {
518 printk(KERN_ERR "cpufreq: bus-frequencies incorrect or missing\n");
521 ratio = of_get_property(cpunode, "processor-to-bus-ratio*2",
524 printk(KERN_ERR "cpufreq: processor-to-bus-ratio*2 missing\n");
528 /* Get the min/max bus frequencies */
529 low_freq = min(freqs[0], freqs[1]);
530 hi_freq = max(freqs[0], freqs[1]);
532 /* Grrrr.. It _seems_ that the device-tree is lying on the low bus
533 * frequency, it claims it to be around 84Mhz on some models while
534 * it appears to be approx. 101Mhz on all. Let's hack around here...
535 * fortunately, we don't need to be too precise
537 if (low_freq < 98000000)
538 low_freq = 101000000;
540 /* Convert those to CPU core clocks */
541 low_freq = (low_freq * (*ratio)) / 2000;
542 hi_freq = (hi_freq * (*ratio)) / 2000;
544 /* Now we get the frequencies, we read the GPIO to see what is out current
547 rc = pmac_call_feature(PMAC_FTR_READ_GPIO, NULL, frequency_gpio, 0);
548 cur_freq = (rc & 0x01) ? hi_freq : low_freq;
550 set_speed_proc = gpios_set_cpu_speed;
554 /* If we use the PMU, look for the min & max frequencies in the
557 value = of_get_property(cpunode, "min-clock-frequency", NULL);
560 low_freq = (*value) / 1000;
561 /* The PowerBook G4 12" (PowerBook6,1) has an error in the device-tree
563 if (low_freq < 100000)
566 value = of_get_property(cpunode, "max-clock-frequency", NULL);
569 hi_freq = (*value) / 1000;
570 set_speed_proc = pmu_set_cpu_speed;
576 static int pmac_cpufreq_init_7447A(struct device_node *cpunode)
578 struct device_node *volt_gpio_np;
580 if (of_get_property(cpunode, "dynamic-power-step", NULL) == NULL)
583 volt_gpio_np = of_find_node_by_name(NULL, "cpu-vcore-select");
585 voltage_gpio = read_gpio(volt_gpio_np);
587 printk(KERN_ERR "cpufreq: missing cpu-vcore-select gpio\n");
591 /* OF only reports the high frequency */
593 low_freq = cur_freq/2;
595 /* Read actual frequency from CPU */
596 cur_freq = dfs_get_cpu_speed();
597 set_speed_proc = dfs_set_cpu_speed;
598 get_speed_proc = dfs_get_cpu_speed;
603 static int pmac_cpufreq_init_750FX(struct device_node *cpunode)
605 struct device_node *volt_gpio_np;
609 if (of_get_property(cpunode, "dynamic-power-step", NULL) == NULL)
613 value = of_get_property(cpunode, "reduced-clock-frequency", NULL);
616 low_freq = (*value) / 1000;
618 volt_gpio_np = of_find_node_by_name(NULL, "cpu-vcore-select");
620 voltage_gpio = read_gpio(volt_gpio_np);
622 pvr = mfspr(SPRN_PVR);
623 has_cpu_l2lve = !((pvr & 0xf00) == 0x100);
625 set_speed_proc = cpu_750fx_cpu_speed;
626 get_speed_proc = cpu_750fx_get_cpu_speed;
627 cur_freq = cpu_750fx_get_cpu_speed();
632 /* Currently, we support the following machines:
634 * - Titanium PowerBook 1Ghz (PMU based, 667Mhz & 1Ghz)
635 * - Titanium PowerBook 800 (PMU based, 667Mhz & 800Mhz)
636 * - Titanium PowerBook 400 (PMU based, 300Mhz & 400Mhz)
637 * - Titanium PowerBook 500 (PMU based, 300Mhz & 500Mhz)
638 * - iBook2 500/600 (PMU based, 400Mhz & 500/600Mhz)
639 * - iBook2 700 (CPU based, 400Mhz & 700Mhz, support low voltage)
640 * - Recent MacRISC3 laptops
641 * - All new machines with 7447A CPUs
643 static int __init pmac_cpufreq_setup(void)
645 struct device_node *cpunode;
648 if (strstr(cmd_line, "nocpufreq"))
651 /* Assume only one CPU */
652 cpunode = of_find_node_by_type(NULL, "cpu");
656 /* Get current cpu clock freq */
657 value = of_get_property(cpunode, "clock-frequency", NULL);
660 cur_freq = (*value) / 1000;
662 /* Check for 7447A based MacRISC3 */
663 if (of_machine_is_compatible("MacRISC3") &&
664 of_get_property(cpunode, "dynamic-power-step", NULL) &&
665 PVR_VER(mfspr(SPRN_PVR)) == 0x8003) {
666 pmac_cpufreq_init_7447A(cpunode);
667 /* Check for other MacRISC3 machines */
668 } else if (of_machine_is_compatible("PowerBook3,4") ||
669 of_machine_is_compatible("PowerBook3,5") ||
670 of_machine_is_compatible("MacRISC3")) {
671 pmac_cpufreq_init_MacRISC3(cpunode);
672 /* Else check for iBook2 500/600 */
673 } else if (of_machine_is_compatible("PowerBook4,1")) {
676 set_speed_proc = pmu_set_cpu_speed;
679 /* Else check for TiPb 550 */
680 else if (of_machine_is_compatible("PowerBook3,3") && cur_freq == 550000) {
683 set_speed_proc = pmu_set_cpu_speed;
686 /* Else check for TiPb 400 & 500 */
687 else if (of_machine_is_compatible("PowerBook3,2")) {
688 /* We only know about the 400 MHz and the 500Mhz model
689 * they both have 300 MHz as low frequency
691 if (cur_freq < 350000 || cur_freq > 550000)
695 set_speed_proc = pmu_set_cpu_speed;
698 /* Else check for 750FX */
699 else if (PVR_VER(mfspr(SPRN_PVR)) == 0x7000)
700 pmac_cpufreq_init_750FX(cpunode);
702 of_node_put(cpunode);
703 if (set_speed_proc == NULL)
706 pmac_cpu_freqs[CPUFREQ_LOW].frequency = low_freq;
707 pmac_cpu_freqs[CPUFREQ_HIGH].frequency = hi_freq;
708 ppc_proc_freq = cur_freq * 1000ul;
710 printk(KERN_INFO "Registering PowerMac CPU frequency driver\n");
711 printk(KERN_INFO "Low: %d Mhz, High: %d Mhz, Boot: %d Mhz\n",
712 low_freq/1000, hi_freq/1000, cur_freq/1000);
714 return cpufreq_register_driver(&pmac_cpufreq_driver);
717 module_init(pmac_cpufreq_setup);