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,
377 unsigned int target_freq,
378 unsigned int relation)
380 unsigned int newstate = 0;
383 if (cpufreq_frequency_table_target(policy, pmac_cpu_freqs,
384 target_freq, relation, &newstate))
387 rc = do_set_cpu_speed(policy, newstate, 1);
389 ppc_proc_freq = cur_freq * 1000ul;
393 static int pmac_cpufreq_cpu_init(struct cpufreq_policy *policy)
395 return cpufreq_generic_init(policy, pmac_cpu_freqs, transition_latency);
398 static u32 read_gpio(struct device_node *np)
400 const u32 *reg = of_get_property(np, "reg", NULL);
405 /* That works for all keylargos but shall be fixed properly
406 * some day... The problem is that it seems we can't rely
407 * on the "reg" property of the GPIO nodes, they are either
408 * relative to the base of KeyLargo or to the base of the
409 * GPIO space, and the device-tree doesn't help.
412 if (offset < KEYLARGO_GPIO_LEVELS0)
413 offset += KEYLARGO_GPIO_LEVELS0;
417 static int pmac_cpufreq_suspend(struct cpufreq_policy *policy)
419 /* Ok, this could be made a bit smarter, but let's be robust for now. We
420 * always force a speed change to high speed before sleep, to make sure
421 * we have appropriate voltage and/or bus speed for the wakeup process,
422 * and to make sure our loops_per_jiffies are "good enough", that is will
423 * not cause too short delays if we sleep in low speed and wake in high
427 sleep_freq = cur_freq;
428 if (cur_freq == low_freq && !is_pmu_based)
429 do_set_cpu_speed(policy, CPUFREQ_HIGH, 0);
433 static int pmac_cpufreq_resume(struct cpufreq_policy *policy)
435 /* If we resume, first check if we have a get() function */
437 cur_freq = get_speed_proc();
441 /* We don't, hrm... we don't really know our speed here, best
442 * is that we force a switch to whatever it was, which is
443 * probably high speed due to our suspend() routine
445 do_set_cpu_speed(policy, sleep_freq == low_freq ?
446 CPUFREQ_LOW : CPUFREQ_HIGH, 0);
448 ppc_proc_freq = cur_freq * 1000ul;
454 static struct cpufreq_driver pmac_cpufreq_driver = {
455 .verify = cpufreq_generic_frequency_table_verify,
456 .target = pmac_cpufreq_target,
457 .get = pmac_cpufreq_get_speed,
458 .init = pmac_cpufreq_cpu_init,
459 .suspend = pmac_cpufreq_suspend,
460 .resume = pmac_cpufreq_resume,
461 .flags = CPUFREQ_PM_NO_WARN,
462 .attr = cpufreq_generic_attr,
467 static int pmac_cpufreq_init_MacRISC3(struct device_node *cpunode)
469 struct device_node *volt_gpio_np = of_find_node_by_name(NULL,
471 struct device_node *freq_gpio_np = of_find_node_by_name(NULL,
473 struct device_node *slew_done_gpio_np = of_find_node_by_name(NULL,
478 * Check to see if it's GPIO driven or PMU only
480 * The way we extract the GPIO address is slightly hackish, but it
481 * works well enough for now. We need to abstract the whole GPIO
482 * stuff sooner or later anyway
486 voltage_gpio = read_gpio(volt_gpio_np);
488 frequency_gpio = read_gpio(freq_gpio_np);
489 if (slew_done_gpio_np)
490 slew_done_gpio = read_gpio(slew_done_gpio_np);
492 /* If we use the frequency GPIOs, calculate the min/max speeds based
493 * on the bus frequencies
495 if (frequency_gpio && slew_done_gpio) {
497 const u32 *freqs, *ratio;
499 freqs = of_get_property(cpunode, "bus-frequencies", &lenp);
501 if (freqs == NULL || lenp != 2) {
502 printk(KERN_ERR "cpufreq: bus-frequencies incorrect or missing\n");
505 ratio = of_get_property(cpunode, "processor-to-bus-ratio*2",
508 printk(KERN_ERR "cpufreq: processor-to-bus-ratio*2 missing\n");
512 /* Get the min/max bus frequencies */
513 low_freq = min(freqs[0], freqs[1]);
514 hi_freq = max(freqs[0], freqs[1]);
516 /* Grrrr.. It _seems_ that the device-tree is lying on the low bus
517 * frequency, it claims it to be around 84Mhz on some models while
518 * it appears to be approx. 101Mhz on all. Let's hack around here...
519 * fortunately, we don't need to be too precise
521 if (low_freq < 98000000)
522 low_freq = 101000000;
524 /* Convert those to CPU core clocks */
525 low_freq = (low_freq * (*ratio)) / 2000;
526 hi_freq = (hi_freq * (*ratio)) / 2000;
528 /* Now we get the frequencies, we read the GPIO to see what is out current
531 rc = pmac_call_feature(PMAC_FTR_READ_GPIO, NULL, frequency_gpio, 0);
532 cur_freq = (rc & 0x01) ? hi_freq : low_freq;
534 set_speed_proc = gpios_set_cpu_speed;
538 /* If we use the PMU, look for the min & max frequencies in the
541 value = of_get_property(cpunode, "min-clock-frequency", NULL);
544 low_freq = (*value) / 1000;
545 /* The PowerBook G4 12" (PowerBook6,1) has an error in the device-tree
547 if (low_freq < 100000)
550 value = of_get_property(cpunode, "max-clock-frequency", NULL);
553 hi_freq = (*value) / 1000;
554 set_speed_proc = pmu_set_cpu_speed;
560 static int pmac_cpufreq_init_7447A(struct device_node *cpunode)
562 struct device_node *volt_gpio_np;
564 if (of_get_property(cpunode, "dynamic-power-step", NULL) == NULL)
567 volt_gpio_np = of_find_node_by_name(NULL, "cpu-vcore-select");
569 voltage_gpio = read_gpio(volt_gpio_np);
571 printk(KERN_ERR "cpufreq: missing cpu-vcore-select gpio\n");
575 /* OF only reports the high frequency */
577 low_freq = cur_freq/2;
579 /* Read actual frequency from CPU */
580 cur_freq = dfs_get_cpu_speed();
581 set_speed_proc = dfs_set_cpu_speed;
582 get_speed_proc = dfs_get_cpu_speed;
587 static int pmac_cpufreq_init_750FX(struct device_node *cpunode)
589 struct device_node *volt_gpio_np;
593 if (of_get_property(cpunode, "dynamic-power-step", NULL) == NULL)
597 value = of_get_property(cpunode, "reduced-clock-frequency", NULL);
600 low_freq = (*value) / 1000;
602 volt_gpio_np = of_find_node_by_name(NULL, "cpu-vcore-select");
604 voltage_gpio = read_gpio(volt_gpio_np);
606 pvr = mfspr(SPRN_PVR);
607 has_cpu_l2lve = !((pvr & 0xf00) == 0x100);
609 set_speed_proc = cpu_750fx_cpu_speed;
610 get_speed_proc = cpu_750fx_get_cpu_speed;
611 cur_freq = cpu_750fx_get_cpu_speed();
616 /* Currently, we support the following machines:
618 * - Titanium PowerBook 1Ghz (PMU based, 667Mhz & 1Ghz)
619 * - Titanium PowerBook 800 (PMU based, 667Mhz & 800Mhz)
620 * - Titanium PowerBook 400 (PMU based, 300Mhz & 400Mhz)
621 * - Titanium PowerBook 500 (PMU based, 300Mhz & 500Mhz)
622 * - iBook2 500/600 (PMU based, 400Mhz & 500/600Mhz)
623 * - iBook2 700 (CPU based, 400Mhz & 700Mhz, support low voltage)
624 * - Recent MacRISC3 laptops
625 * - All new machines with 7447A CPUs
627 static int __init pmac_cpufreq_setup(void)
629 struct device_node *cpunode;
632 if (strstr(cmd_line, "nocpufreq"))
635 /* Get first CPU node */
636 cpunode = of_cpu_device_node_get(0);
640 /* Get current cpu clock freq */
641 value = of_get_property(cpunode, "clock-frequency", NULL);
644 cur_freq = (*value) / 1000;
645 transition_latency = CPUFREQ_ETERNAL;
647 /* Check for 7447A based MacRISC3 */
648 if (of_machine_is_compatible("MacRISC3") &&
649 of_get_property(cpunode, "dynamic-power-step", NULL) &&
650 PVR_VER(mfspr(SPRN_PVR)) == 0x8003) {
651 pmac_cpufreq_init_7447A(cpunode);
652 transition_latency = 8000000;
653 /* Check for other MacRISC3 machines */
654 } else if (of_machine_is_compatible("PowerBook3,4") ||
655 of_machine_is_compatible("PowerBook3,5") ||
656 of_machine_is_compatible("MacRISC3")) {
657 pmac_cpufreq_init_MacRISC3(cpunode);
658 /* Else check for iBook2 500/600 */
659 } else if (of_machine_is_compatible("PowerBook4,1")) {
662 set_speed_proc = pmu_set_cpu_speed;
665 /* Else check for TiPb 550 */
666 else if (of_machine_is_compatible("PowerBook3,3") && cur_freq == 550000) {
669 set_speed_proc = pmu_set_cpu_speed;
672 /* Else check for TiPb 400 & 500 */
673 else if (of_machine_is_compatible("PowerBook3,2")) {
674 /* We only know about the 400 MHz and the 500Mhz model
675 * they both have 300 MHz as low frequency
677 if (cur_freq < 350000 || cur_freq > 550000)
681 set_speed_proc = pmu_set_cpu_speed;
684 /* Else check for 750FX */
685 else if (PVR_VER(mfspr(SPRN_PVR)) == 0x7000)
686 pmac_cpufreq_init_750FX(cpunode);
688 of_node_put(cpunode);
689 if (set_speed_proc == NULL)
692 pmac_cpu_freqs[CPUFREQ_LOW].frequency = low_freq;
693 pmac_cpu_freqs[CPUFREQ_HIGH].frequency = hi_freq;
694 ppc_proc_freq = cur_freq * 1000ul;
696 printk(KERN_INFO "Registering PowerMac CPU frequency driver\n");
697 printk(KERN_INFO "Low: %d Mhz, High: %d Mhz, Boot: %d Mhz\n",
698 low_freq/1000, hi_freq/1000, cur_freq/1000);
700 return cpufreq_register_driver(&pmac_cpufreq_driver);
703 module_init(pmac_cpufreq_setup);