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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (C) 2002 - 2005 Benjamin Herrenschmidt <benh@kernel.crashing.org>
4 * Copyright (C) 2004 John Steele Scott <toojays@toojays.net>
5 *
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
9 * type of machine.
10 */
11
12#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
13
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>
26#include <linux/of.h>
27#include <linux/of_address.h>
28
29#include <asm/machdep.h>
30#include <asm/irq.h>
31#include <asm/pmac_feature.h>
32#include <asm/mmu_context.h>
33#include <asm/sections.h>
34#include <asm/cputable.h>
35#include <asm/time.h>
36#include <asm/mpic.h>
37#include <asm/keylargo.h>
38#include <asm/switch_to.h>
39
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
43 */
44#undef DEBUG_FREQ
45
46extern void low_choose_7447a_dfs(int dfs);
47extern void low_choose_750fx_pll(int pll);
48extern void low_sleep_handler(void);
49
50/*
51 * Currently, PowerMac cpufreq supports only high & low frequencies
52 * that are set by the firmware
53 */
54static unsigned int low_freq;
55static unsigned int hi_freq;
56static unsigned int cur_freq;
57static unsigned int sleep_freq;
58static unsigned long transition_latency;
59
60/*
61 * Different models uses different mechanisms to switch the frequency
62 */
63static int (*set_speed_proc)(int low_speed);
64static unsigned int (*get_speed_proc)(void);
65
66/*
67 * Some definitions used by the various speedprocs
68 */
69static u32 voltage_gpio;
70static u32 frequency_gpio;
71static u32 slew_done_gpio;
72static int no_schedule;
73static int has_cpu_l2lve;
74static int is_pmu_based;
75
76/* There are only two frequency states for each processor. Values
77 * are in kHz for the time being.
78 */
79#define CPUFREQ_HIGH 0
80#define CPUFREQ_LOW 1
81
82static struct cpufreq_frequency_table pmac_cpu_freqs[] = {
83 {0, CPUFREQ_HIGH, 0},
84 {0, CPUFREQ_LOW, 0},
85 {0, 0, CPUFREQ_TABLE_END},
86};
87
88static inline void local_delay(unsigned long ms)
89{
90 if (no_schedule)
91 mdelay(ms);
92 else
93 msleep(ms);
94}
95
96#ifdef DEBUG_FREQ
97static inline void debug_calc_bogomips(void)
98{
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.
102 */
103 unsigned long save_lpj = loops_per_jiffy;
104 calibrate_delay();
105 loops_per_jiffy = save_lpj;
106}
107#endif /* DEBUG_FREQ */
108
109/* Switch CPU speed under 750FX CPU control
110 */
111static int cpu_750fx_cpu_speed(int low_speed)
112{
113 u32 hid2;
114
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 */
119 local_delay(10);
120
121 /* tweak L2 for high voltage */
122 if (has_cpu_l2lve) {
123 hid2 = mfspr(SPRN_HID2);
124 hid2 &= ~0x2000;
125 mtspr(SPRN_HID2, hid2);
126 }
127 }
128#ifdef CONFIG_PPC_BOOK3S_32
129 low_choose_750fx_pll(low_speed);
130#endif
131 if (low_speed == 1) {
132 /* tweak L2 for low voltage */
133 if (has_cpu_l2lve) {
134 hid2 = mfspr(SPRN_HID2);
135 hid2 |= 0x2000;
136 mtspr(SPRN_HID2, hid2);
137 }
138
139 /* ramping down, set voltage last */
140 pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, voltage_gpio, 0x04);
141 local_delay(10);
142 }
143
144 return 0;
145}
146
147static unsigned int cpu_750fx_get_cpu_speed(void)
148{
149 if (mfspr(SPRN_HID1) & HID1_PS)
150 return low_freq;
151 else
152 return hi_freq;
153}
154
155/* Switch CPU speed using DFS */
156static int dfs_set_cpu_speed(int low_speed)
157{
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 */
162 local_delay(1);
163 }
164
165 /* set frequency */
166#ifdef CONFIG_PPC_BOOK3S_32
167 low_choose_7447a_dfs(low_speed);
168#endif
169 udelay(100);
170
171 if (low_speed == 1) {
172 /* ramping down, set voltage last */
173 pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, voltage_gpio, 0x04);
174 local_delay(1);
175 }
176
177 return 0;
178}
179
180static unsigned int dfs_get_cpu_speed(void)
181{
182 if (mfspr(SPRN_HID1) & HID1_DFS)
183 return low_freq;
184 else
185 return hi_freq;
186}
187
188
189/* Switch CPU speed using slewing GPIOs
190 */
191static int gpios_set_cpu_speed(int low_speed)
192{
193 int gpio, timeout = 0;
194
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 */
199 local_delay(10);
200 }
201
202 /* Set frequency */
203 gpio = pmac_call_feature(PMAC_FTR_READ_GPIO, NULL, frequency_gpio, 0);
204 if (low_speed == ((gpio & 0x01) == 0))
205 goto skip;
206
207 pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, frequency_gpio,
208 low_speed ? 0x04 : 0x05);
209 udelay(200);
210 do {
211 if (++timeout > 100)
212 break;
213 local_delay(1);
214 gpio = pmac_call_feature(PMAC_FTR_READ_GPIO, NULL, slew_done_gpio, 0);
215 } while((gpio & 0x02) == 0);
216 skip:
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 */
221 local_delay(10);
222 }
223
224#ifdef DEBUG_FREQ
225 debug_calc_bogomips();
226#endif
227
228 return 0;
229}
230
231/* Switch CPU speed under PMU control
232 */
233static int pmu_set_cpu_speed(int low_speed)
234{
235 struct adb_request req;
236 unsigned long save_l2cr;
237 unsigned long save_l3cr;
238 unsigned int pic_prio;
239 unsigned long flags;
240
241 preempt_disable();
242
243#ifdef DEBUG_FREQ
244 printk(KERN_DEBUG "HID1, before: %x\n", mfspr(SPRN_HID1));
245#endif
246 pmu_suspend();
247
248 /* Disable all interrupt sources on openpic */
249 pic_prio = mpic_cpu_get_priority();
250 mpic_cpu_set_priority(0xf);
251
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 */
256 mb();
257 asm volatile("mtdec %0" : : "r" (0x7fffffff));
258
259 /* We can now disable MSR_EE */
260 local_irq_save(flags);
261
262 /* Giveup the FPU & vec */
263 enable_kernel_fp();
264
265#ifdef CONFIG_ALTIVEC
266 if (cpu_has_feature(CPU_FTR_ALTIVEC))
267 enable_kernel_altivec();
268#endif /* CONFIG_ALTIVEC */
269
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) */
273
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
276 */
277 pmu_request(&req, NULL, 6, PMU_CPU_SPEED, 'W', 'O', 'O', 'F', low_speed);
278 while (!req.complete)
279 pmu_poll();
280
281 /* Prepare the northbridge for the speed transition */
282 pmac_call_feature(PMAC_FTR_SLEEP_STATE,NULL,1,1);
283
284 /* Call low level code to backup CPU state and recover from
285 * hardware reset
286 */
287 low_sleep_handler();
288
289 /* Restore the northbridge */
290 pmac_call_feature(PMAC_FTR_SLEEP_STATE,NULL,1,0);
291
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);
298
299 /* Restore userland MMU context */
300 switch_mmu_context(NULL, current->active_mm, NULL);
301
302#ifdef DEBUG_FREQ
303 printk(KERN_DEBUG "HID1, after: %x\n", mfspr(SPRN_HID1));
304#endif
305
306 /* Restore low level PMU operations */
307 pmu_unlock();
308
309 /*
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.
313 */
314 set_dec(1);
315
316 /* Restore interrupts */
317 mpic_cpu_set_priority(pic_prio);
318
319 /* Let interrupts flow again ... */
320 local_irq_restore(flags);
321
322#ifdef DEBUG_FREQ
323 debug_calc_bogomips();
324#endif
325
326 pmu_resume();
327
328 preempt_enable();
329
330 return 0;
331}
332
333static int do_set_cpu_speed(struct cpufreq_policy *policy, int speed_mode)
334{
335 unsigned long l3cr;
336 static unsigned long prev_l3cr;
337
338 if (speed_mode == CPUFREQ_LOW &&
339 cpu_has_feature(CPU_FTR_L3CR)) {
340 l3cr = _get_L3CR();
341 if (l3cr & L3CR_L3E) {
342 prev_l3cr = l3cr;
343 _set_L3CR(0);
344 }
345 }
346 set_speed_proc(speed_mode == CPUFREQ_LOW);
347 if (speed_mode == CPUFREQ_HIGH &&
348 cpu_has_feature(CPU_FTR_L3CR)) {
349 l3cr = _get_L3CR();
350 if ((prev_l3cr & L3CR_L3E) && l3cr != prev_l3cr)
351 _set_L3CR(prev_l3cr);
352 }
353 cur_freq = (speed_mode == CPUFREQ_HIGH) ? hi_freq : low_freq;
354
355 return 0;
356}
357
358static unsigned int pmac_cpufreq_get_speed(unsigned int cpu)
359{
360 return cur_freq;
361}
362
363static int pmac_cpufreq_target( struct cpufreq_policy *policy,
364 unsigned int index)
365{
366 int rc;
367
368 rc = do_set_cpu_speed(policy, index);
369
370 ppc_proc_freq = cur_freq * 1000ul;
371 return rc;
372}
373
374static int pmac_cpufreq_cpu_init(struct cpufreq_policy *policy)
375{
376 cpufreq_generic_init(policy, pmac_cpu_freqs, transition_latency);
377 return 0;
378}
379
380static u32 read_gpio(struct device_node *np)
381{
382 u64 offset;
383
384 if (of_property_read_reg(np, 0, &offset, NULL) < 0)
385 return 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.
391 */
392 if (offset < KEYLARGO_GPIO_LEVELS0)
393 offset += KEYLARGO_GPIO_LEVELS0;
394 return offset;
395}
396
397static int pmac_cpufreq_suspend(struct cpufreq_policy *policy)
398{
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
404 * speed..
405 */
406 no_schedule = 1;
407 sleep_freq = cur_freq;
408 if (cur_freq == low_freq && !is_pmu_based)
409 do_set_cpu_speed(policy, CPUFREQ_HIGH);
410 return 0;
411}
412
413static int pmac_cpufreq_resume(struct cpufreq_policy *policy)
414{
415 /* If we resume, first check if we have a get() function */
416 if (get_speed_proc)
417 cur_freq = get_speed_proc();
418 else
419 cur_freq = 0;
420
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
424 */
425 do_set_cpu_speed(policy, sleep_freq == low_freq ?
426 CPUFREQ_LOW : CPUFREQ_HIGH);
427
428 ppc_proc_freq = cur_freq * 1000ul;
429
430 no_schedule = 0;
431 return 0;
432}
433
434static 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,
443 .name = "powermac",
444};
445
446
447static int pmac_cpufreq_init_MacRISC3(struct device_node *cpunode)
448{
449 struct device_node *volt_gpio_np = of_find_node_by_name(NULL,
450 "voltage-gpio");
451 struct device_node *freq_gpio_np = of_find_node_by_name(NULL,
452 "frequency-gpio");
453 struct device_node *slew_done_gpio_np = of_find_node_by_name(NULL,
454 "slewing-done");
455 const u32 *value;
456
457 /*
458 * Check to see if it's GPIO driven or PMU only
459 *
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
463 */
464
465 if (volt_gpio_np)
466 voltage_gpio = read_gpio(volt_gpio_np);
467 if (freq_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);
471
472 of_node_put(volt_gpio_np);
473 of_node_put(freq_gpio_np);
474 of_node_put(slew_done_gpio_np);
475
476 /* If we use the frequency GPIOs, calculate the min/max speeds based
477 * on the bus frequencies
478 */
479 if (frequency_gpio && slew_done_gpio) {
480 int lenp, rc;
481 const u32 *freqs, *ratio;
482
483 freqs = of_get_property(cpunode, "bus-frequencies", &lenp);
484 lenp /= sizeof(u32);
485 if (freqs == NULL || lenp != 2) {
486 pr_err("bus-frequencies incorrect or missing\n");
487 return 1;
488 }
489 ratio = of_get_property(cpunode, "processor-to-bus-ratio*2",
490 NULL);
491 if (ratio == NULL) {
492 pr_err("processor-to-bus-ratio*2 missing\n");
493 return 1;
494 }
495
496 /* Get the min/max bus frequencies */
497 low_freq = min(freqs[0], freqs[1]);
498 hi_freq = max(freqs[0], freqs[1]);
499
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
504 */
505 if (low_freq < 98000000)
506 low_freq = 101000000;
507
508 /* Convert those to CPU core clocks */
509 low_freq = (low_freq * (*ratio)) / 2000;
510 hi_freq = (hi_freq * (*ratio)) / 2000;
511
512 /* Now we get the frequencies, we read the GPIO to see what is out current
513 * speed
514 */
515 rc = pmac_call_feature(PMAC_FTR_READ_GPIO, NULL, frequency_gpio, 0);
516 cur_freq = (rc & 0x01) ? hi_freq : low_freq;
517
518 set_speed_proc = gpios_set_cpu_speed;
519 return 1;
520 }
521
522 /* If we use the PMU, look for the min & max frequencies in the
523 * device-tree
524 */
525 value = of_get_property(cpunode, "min-clock-frequency", NULL);
526 if (!value)
527 return 1;
528 low_freq = (*value) / 1000;
529 /* The PowerBook G4 12" (PowerBook6,1) has an error in the device-tree
530 * here */
531 if (low_freq < 100000)
532 low_freq *= 10;
533
534 value = of_get_property(cpunode, "max-clock-frequency", NULL);
535 if (!value)
536 return 1;
537 hi_freq = (*value) / 1000;
538 set_speed_proc = pmu_set_cpu_speed;
539 is_pmu_based = 1;
540
541 return 0;
542}
543
544static int pmac_cpufreq_init_7447A(struct device_node *cpunode)
545{
546 struct device_node *volt_gpio_np;
547
548 if (!of_property_read_bool(cpunode, "dynamic-power-step"))
549 return 1;
550
551 volt_gpio_np = of_find_node_by_name(NULL, "cpu-vcore-select");
552 if (volt_gpio_np)
553 voltage_gpio = read_gpio(volt_gpio_np);
554 of_node_put(volt_gpio_np);
555 if (!voltage_gpio){
556 pr_err("missing cpu-vcore-select gpio\n");
557 return 1;
558 }
559
560 /* OF only reports the high frequency */
561 hi_freq = cur_freq;
562 low_freq = cur_freq/2;
563
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;
568
569 return 0;
570}
571
572static int pmac_cpufreq_init_750FX(struct device_node *cpunode)
573{
574 struct device_node *volt_gpio_np;
575 u32 pvr;
576 const u32 *value;
577
578 if (!of_property_read_bool(cpunode, "dynamic-power-step"))
579 return 1;
580
581 hi_freq = cur_freq;
582 value = of_get_property(cpunode, "reduced-clock-frequency", NULL);
583 if (!value)
584 return 1;
585 low_freq = (*value) / 1000;
586
587 volt_gpio_np = of_find_node_by_name(NULL, "cpu-vcore-select");
588 if (volt_gpio_np)
589 voltage_gpio = read_gpio(volt_gpio_np);
590
591 of_node_put(volt_gpio_np);
592 pvr = mfspr(SPRN_PVR);
593 has_cpu_l2lve = !((pvr & 0xf00) == 0x100);
594
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();
598
599 return 0;
600}
601
602/* Currently, we support the following machines:
603 *
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
612 */
613static int __init pmac_cpufreq_setup(void)
614{
615 struct device_node *cpunode;
616 const u32 *value;
617
618 if (strstr(boot_command_line, "nocpufreq"))
619 return 0;
620
621 /* Get first CPU node */
622 cpunode = of_cpu_device_node_get(0);
623 if (!cpunode)
624 goto out;
625
626 /* Get current cpu clock freq */
627 value = of_get_property(cpunode, "clock-frequency", NULL);
628 if (!value)
629 goto out;
630 cur_freq = (*value) / 1000;
631
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);
637
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")) {
648 hi_freq = cur_freq;
649 low_freq = 400000;
650 set_speed_proc = pmu_set_cpu_speed;
651 is_pmu_based = 1;
652 }
653 /* Else check for TiPb 550 */
654 else if (of_machine_is_compatible("PowerBook3,3") && cur_freq == 550000) {
655 hi_freq = cur_freq;
656 low_freq = 500000;
657 set_speed_proc = pmu_set_cpu_speed;
658 is_pmu_based = 1;
659 }
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
664 */
665 if (cur_freq < 350000 || cur_freq > 550000)
666 goto out;
667 hi_freq = cur_freq;
668 low_freq = 300000;
669 set_speed_proc = pmu_set_cpu_speed;
670 is_pmu_based = 1;
671 }
672 /* Else check for 750FX */
673 else if (PVR_VER(mfspr(SPRN_PVR)) == 0x7000)
674 pmac_cpufreq_init_750FX(cpunode);
675out:
676 of_node_put(cpunode);
677 if (set_speed_proc == NULL)
678 return -ENODEV;
679
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;
683
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);
687
688 return cpufreq_register_driver(&pmac_cpufreq_driver);
689}
690
691module_init(pmac_cpufreq_setup);
692
1/*
2 * Copyright (C) 2002 - 2005 Benjamin Herrenschmidt <benh@kernel.crashing.org>
3 * Copyright (C) 2004 John Steele Scott <toojays@toojays.net>
4 *
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.
8 *
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
12 * type of machine.
13 *
14 */
15
16#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
17
18#include <linux/module.h>
19#include <linux/types.h>
20#include <linux/errno.h>
21#include <linux/kernel.h>
22#include <linux/delay.h>
23#include <linux/sched.h>
24#include <linux/adb.h>
25#include <linux/pmu.h>
26#include <linux/cpufreq.h>
27#include <linux/init.h>
28#include <linux/device.h>
29#include <linux/hardirq.h>
30#include <linux/of_device.h>
31#include <asm/prom.h>
32#include <asm/machdep.h>
33#include <asm/irq.h>
34#include <asm/pmac_feature.h>
35#include <asm/mmu_context.h>
36#include <asm/sections.h>
37#include <asm/cputable.h>
38#include <asm/time.h>
39#include <asm/mpic.h>
40#include <asm/keylargo.h>
41#include <asm/switch_to.h>
42
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
46 */
47#undef DEBUG_FREQ
48
49extern void low_choose_7447a_dfs(int dfs);
50extern void low_choose_750fx_pll(int pll);
51extern void low_sleep_handler(void);
52
53/*
54 * Currently, PowerMac cpufreq supports only high & low frequencies
55 * that are set by the firmware
56 */
57static unsigned int low_freq;
58static unsigned int hi_freq;
59static unsigned int cur_freq;
60static unsigned int sleep_freq;
61static unsigned long transition_latency;
62
63/*
64 * Different models uses different mechanisms to switch the frequency
65 */
66static int (*set_speed_proc)(int low_speed);
67static unsigned int (*get_speed_proc)(void);
68
69/*
70 * Some definitions used by the various speedprocs
71 */
72static u32 voltage_gpio;
73static u32 frequency_gpio;
74static u32 slew_done_gpio;
75static int no_schedule;
76static int has_cpu_l2lve;
77static int is_pmu_based;
78
79/* There are only two frequency states for each processor. Values
80 * are in kHz for the time being.
81 */
82#define CPUFREQ_HIGH 0
83#define CPUFREQ_LOW 1
84
85static struct cpufreq_frequency_table pmac_cpu_freqs[] = {
86 {0, CPUFREQ_HIGH, 0},
87 {0, CPUFREQ_LOW, 0},
88 {0, 0, CPUFREQ_TABLE_END},
89};
90
91static inline void local_delay(unsigned long ms)
92{
93 if (no_schedule)
94 mdelay(ms);
95 else
96 msleep(ms);
97}
98
99#ifdef DEBUG_FREQ
100static inline void debug_calc_bogomips(void)
101{
102 /* This will cause a recalc of bogomips and display the
103 * result. We backup/restore the value to avoid affecting the
104 * core cpufreq framework's own calculation.
105 */
106 unsigned long save_lpj = loops_per_jiffy;
107 calibrate_delay();
108 loops_per_jiffy = save_lpj;
109}
110#endif /* DEBUG_FREQ */
111
112/* Switch CPU speed under 750FX CPU control
113 */
114static int cpu_750fx_cpu_speed(int low_speed)
115{
116 u32 hid2;
117
118 if (low_speed == 0) {
119 /* ramping up, set voltage first */
120 pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, voltage_gpio, 0x05);
121 /* Make sure we sleep for at least 1ms */
122 local_delay(10);
123
124 /* tweak L2 for high voltage */
125 if (has_cpu_l2lve) {
126 hid2 = mfspr(SPRN_HID2);
127 hid2 &= ~0x2000;
128 mtspr(SPRN_HID2, hid2);
129 }
130 }
131#ifdef CONFIG_6xx
132 low_choose_750fx_pll(low_speed);
133#endif
134 if (low_speed == 1) {
135 /* tweak L2 for low voltage */
136 if (has_cpu_l2lve) {
137 hid2 = mfspr(SPRN_HID2);
138 hid2 |= 0x2000;
139 mtspr(SPRN_HID2, hid2);
140 }
141
142 /* ramping down, set voltage last */
143 pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, voltage_gpio, 0x04);
144 local_delay(10);
145 }
146
147 return 0;
148}
149
150static unsigned int cpu_750fx_get_cpu_speed(void)
151{
152 if (mfspr(SPRN_HID1) & HID1_PS)
153 return low_freq;
154 else
155 return hi_freq;
156}
157
158/* Switch CPU speed using DFS */
159static int dfs_set_cpu_speed(int low_speed)
160{
161 if (low_speed == 0) {
162 /* ramping up, set voltage first */
163 pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, voltage_gpio, 0x05);
164 /* Make sure we sleep for at least 1ms */
165 local_delay(1);
166 }
167
168 /* set frequency */
169#ifdef CONFIG_6xx
170 low_choose_7447a_dfs(low_speed);
171#endif
172 udelay(100);
173
174 if (low_speed == 1) {
175 /* ramping down, set voltage last */
176 pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, voltage_gpio, 0x04);
177 local_delay(1);
178 }
179
180 return 0;
181}
182
183static unsigned int dfs_get_cpu_speed(void)
184{
185 if (mfspr(SPRN_HID1) & HID1_DFS)
186 return low_freq;
187 else
188 return hi_freq;
189}
190
191
192/* Switch CPU speed using slewing GPIOs
193 */
194static int gpios_set_cpu_speed(int low_speed)
195{
196 int gpio, timeout = 0;
197
198 /* If ramping up, set voltage first */
199 if (low_speed == 0) {
200 pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, voltage_gpio, 0x05);
201 /* Delay is way too big but it's ok, we schedule */
202 local_delay(10);
203 }
204
205 /* Set frequency */
206 gpio = pmac_call_feature(PMAC_FTR_READ_GPIO, NULL, frequency_gpio, 0);
207 if (low_speed == ((gpio & 0x01) == 0))
208 goto skip;
209
210 pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, frequency_gpio,
211 low_speed ? 0x04 : 0x05);
212 udelay(200);
213 do {
214 if (++timeout > 100)
215 break;
216 local_delay(1);
217 gpio = pmac_call_feature(PMAC_FTR_READ_GPIO, NULL, slew_done_gpio, 0);
218 } while((gpio & 0x02) == 0);
219 skip:
220 /* If ramping down, set voltage last */
221 if (low_speed == 1) {
222 pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, voltage_gpio, 0x04);
223 /* Delay is way too big but it's ok, we schedule */
224 local_delay(10);
225 }
226
227#ifdef DEBUG_FREQ
228 debug_calc_bogomips();
229#endif
230
231 return 0;
232}
233
234/* Switch CPU speed under PMU control
235 */
236static int pmu_set_cpu_speed(int low_speed)
237{
238 struct adb_request req;
239 unsigned long save_l2cr;
240 unsigned long save_l3cr;
241 unsigned int pic_prio;
242 unsigned long flags;
243
244 preempt_disable();
245
246#ifdef DEBUG_FREQ
247 printk(KERN_DEBUG "HID1, before: %x\n", mfspr(SPRN_HID1));
248#endif
249 pmu_suspend();
250
251 /* Disable all interrupt sources on openpic */
252 pic_prio = mpic_cpu_get_priority();
253 mpic_cpu_set_priority(0xf);
254
255 /* Make sure the decrementer won't interrupt us */
256 asm volatile("mtdec %0" : : "r" (0x7fffffff));
257 /* Make sure any pending DEC interrupt occurring while we did
258 * the above didn't re-enable the DEC */
259 mb();
260 asm volatile("mtdec %0" : : "r" (0x7fffffff));
261
262 /* We can now disable MSR_EE */
263 local_irq_save(flags);
264
265 /* Giveup the FPU & vec */
266 enable_kernel_fp();
267
268#ifdef CONFIG_ALTIVEC
269 if (cpu_has_feature(CPU_FTR_ALTIVEC))
270 enable_kernel_altivec();
271#endif /* CONFIG_ALTIVEC */
272
273 /* Save & disable L2 and L3 caches */
274 save_l3cr = _get_L3CR(); /* (returns -1 if not available) */
275 save_l2cr = _get_L2CR(); /* (returns -1 if not available) */
276
277 /* Send the new speed command. My assumption is that this command
278 * will cause PLL_CFG[0..3] to be changed next time CPU goes to sleep
279 */
280 pmu_request(&req, NULL, 6, PMU_CPU_SPEED, 'W', 'O', 'O', 'F', low_speed);
281 while (!req.complete)
282 pmu_poll();
283
284 /* Prepare the northbridge for the speed transition */
285 pmac_call_feature(PMAC_FTR_SLEEP_STATE,NULL,1,1);
286
287 /* Call low level code to backup CPU state and recover from
288 * hardware reset
289 */
290 low_sleep_handler();
291
292 /* Restore the northbridge */
293 pmac_call_feature(PMAC_FTR_SLEEP_STATE,NULL,1,0);
294
295 /* Restore L2 cache */
296 if (save_l2cr != 0xffffffff && (save_l2cr & L2CR_L2E) != 0)
297 _set_L2CR(save_l2cr);
298 /* Restore L3 cache */
299 if (save_l3cr != 0xffffffff && (save_l3cr & L3CR_L3E) != 0)
300 _set_L3CR(save_l3cr);
301
302 /* Restore userland MMU context */
303 switch_mmu_context(NULL, current->active_mm, NULL);
304
305#ifdef DEBUG_FREQ
306 printk(KERN_DEBUG "HID1, after: %x\n", mfspr(SPRN_HID1));
307#endif
308
309 /* Restore low level PMU operations */
310 pmu_unlock();
311
312 /*
313 * Restore decrementer; we'll take a decrementer interrupt
314 * as soon as interrupts are re-enabled and the generic
315 * clockevents code will reprogram it with the right value.
316 */
317 set_dec(1);
318
319 /* Restore interrupts */
320 mpic_cpu_set_priority(pic_prio);
321
322 /* Let interrupts flow again ... */
323 local_irq_restore(flags);
324
325#ifdef DEBUG_FREQ
326 debug_calc_bogomips();
327#endif
328
329 pmu_resume();
330
331 preempt_enable();
332
333 return 0;
334}
335
336static int do_set_cpu_speed(struct cpufreq_policy *policy, int speed_mode)
337{
338 unsigned long l3cr;
339 static unsigned long prev_l3cr;
340
341 if (speed_mode == CPUFREQ_LOW &&
342 cpu_has_feature(CPU_FTR_L3CR)) {
343 l3cr = _get_L3CR();
344 if (l3cr & L3CR_L3E) {
345 prev_l3cr = l3cr;
346 _set_L3CR(0);
347 }
348 }
349 set_speed_proc(speed_mode == CPUFREQ_LOW);
350 if (speed_mode == CPUFREQ_HIGH &&
351 cpu_has_feature(CPU_FTR_L3CR)) {
352 l3cr = _get_L3CR();
353 if ((prev_l3cr & L3CR_L3E) && l3cr != prev_l3cr)
354 _set_L3CR(prev_l3cr);
355 }
356 cur_freq = (speed_mode == CPUFREQ_HIGH) ? hi_freq : low_freq;
357
358 return 0;
359}
360
361static unsigned int pmac_cpufreq_get_speed(unsigned int cpu)
362{
363 return cur_freq;
364}
365
366static int pmac_cpufreq_target( struct cpufreq_policy *policy,
367 unsigned int index)
368{
369 int rc;
370
371 rc = do_set_cpu_speed(policy, index);
372
373 ppc_proc_freq = cur_freq * 1000ul;
374 return rc;
375}
376
377static int pmac_cpufreq_cpu_init(struct cpufreq_policy *policy)
378{
379 return cpufreq_generic_init(policy, pmac_cpu_freqs, transition_latency);
380}
381
382static u32 read_gpio(struct device_node *np)
383{
384 const u32 *reg = of_get_property(np, "reg", NULL);
385 u32 offset;
386
387 if (reg == NULL)
388 return 0;
389 /* That works for all keylargos but shall be fixed properly
390 * some day... The problem is that it seems we can't rely
391 * on the "reg" property of the GPIO nodes, they are either
392 * relative to the base of KeyLargo or to the base of the
393 * GPIO space, and the device-tree doesn't help.
394 */
395 offset = *reg;
396 if (offset < KEYLARGO_GPIO_LEVELS0)
397 offset += KEYLARGO_GPIO_LEVELS0;
398 return offset;
399}
400
401static int pmac_cpufreq_suspend(struct cpufreq_policy *policy)
402{
403 /* Ok, this could be made a bit smarter, but let's be robust for now. We
404 * always force a speed change to high speed before sleep, to make sure
405 * we have appropriate voltage and/or bus speed for the wakeup process,
406 * and to make sure our loops_per_jiffies are "good enough", that is will
407 * not cause too short delays if we sleep in low speed and wake in high
408 * speed..
409 */
410 no_schedule = 1;
411 sleep_freq = cur_freq;
412 if (cur_freq == low_freq && !is_pmu_based)
413 do_set_cpu_speed(policy, CPUFREQ_HIGH);
414 return 0;
415}
416
417static int pmac_cpufreq_resume(struct cpufreq_policy *policy)
418{
419 /* If we resume, first check if we have a get() function */
420 if (get_speed_proc)
421 cur_freq = get_speed_proc();
422 else
423 cur_freq = 0;
424
425 /* We don't, hrm... we don't really know our speed here, best
426 * is that we force a switch to whatever it was, which is
427 * probably high speed due to our suspend() routine
428 */
429 do_set_cpu_speed(policy, sleep_freq == low_freq ?
430 CPUFREQ_LOW : CPUFREQ_HIGH);
431
432 ppc_proc_freq = cur_freq * 1000ul;
433
434 no_schedule = 0;
435 return 0;
436}
437
438static struct cpufreq_driver pmac_cpufreq_driver = {
439 .verify = cpufreq_generic_frequency_table_verify,
440 .target_index = pmac_cpufreq_target,
441 .get = pmac_cpufreq_get_speed,
442 .init = pmac_cpufreq_cpu_init,
443 .suspend = pmac_cpufreq_suspend,
444 .resume = pmac_cpufreq_resume,
445 .flags = CPUFREQ_PM_NO_WARN |
446 CPUFREQ_NO_AUTO_DYNAMIC_SWITCHING,
447 .attr = cpufreq_generic_attr,
448 .name = "powermac",
449};
450
451
452static int pmac_cpufreq_init_MacRISC3(struct device_node *cpunode)
453{
454 struct device_node *volt_gpio_np = of_find_node_by_name(NULL,
455 "voltage-gpio");
456 struct device_node *freq_gpio_np = of_find_node_by_name(NULL,
457 "frequency-gpio");
458 struct device_node *slew_done_gpio_np = of_find_node_by_name(NULL,
459 "slewing-done");
460 const u32 *value;
461
462 /*
463 * Check to see if it's GPIO driven or PMU only
464 *
465 * The way we extract the GPIO address is slightly hackish, but it
466 * works well enough for now. We need to abstract the whole GPIO
467 * stuff sooner or later anyway
468 */
469
470 if (volt_gpio_np)
471 voltage_gpio = read_gpio(volt_gpio_np);
472 if (freq_gpio_np)
473 frequency_gpio = read_gpio(freq_gpio_np);
474 if (slew_done_gpio_np)
475 slew_done_gpio = read_gpio(slew_done_gpio_np);
476
477 /* If we use the frequency GPIOs, calculate the min/max speeds based
478 * on the bus frequencies
479 */
480 if (frequency_gpio && slew_done_gpio) {
481 int lenp, rc;
482 const u32 *freqs, *ratio;
483
484 freqs = of_get_property(cpunode, "bus-frequencies", &lenp);
485 lenp /= sizeof(u32);
486 if (freqs == NULL || lenp != 2) {
487 pr_err("bus-frequencies incorrect or missing\n");
488 return 1;
489 }
490 ratio = of_get_property(cpunode, "processor-to-bus-ratio*2",
491 NULL);
492 if (ratio == NULL) {
493 pr_err("processor-to-bus-ratio*2 missing\n");
494 return 1;
495 }
496
497 /* Get the min/max bus frequencies */
498 low_freq = min(freqs[0], freqs[1]);
499 hi_freq = max(freqs[0], freqs[1]);
500
501 /* Grrrr.. It _seems_ that the device-tree is lying on the low bus
502 * frequency, it claims it to be around 84Mhz on some models while
503 * it appears to be approx. 101Mhz on all. Let's hack around here...
504 * fortunately, we don't need to be too precise
505 */
506 if (low_freq < 98000000)
507 low_freq = 101000000;
508
509 /* Convert those to CPU core clocks */
510 low_freq = (low_freq * (*ratio)) / 2000;
511 hi_freq = (hi_freq * (*ratio)) / 2000;
512
513 /* Now we get the frequencies, we read the GPIO to see what is out current
514 * speed
515 */
516 rc = pmac_call_feature(PMAC_FTR_READ_GPIO, NULL, frequency_gpio, 0);
517 cur_freq = (rc & 0x01) ? hi_freq : low_freq;
518
519 set_speed_proc = gpios_set_cpu_speed;
520 return 1;
521 }
522
523 /* If we use the PMU, look for the min & max frequencies in the
524 * device-tree
525 */
526 value = of_get_property(cpunode, "min-clock-frequency", NULL);
527 if (!value)
528 return 1;
529 low_freq = (*value) / 1000;
530 /* The PowerBook G4 12" (PowerBook6,1) has an error in the device-tree
531 * here */
532 if (low_freq < 100000)
533 low_freq *= 10;
534
535 value = of_get_property(cpunode, "max-clock-frequency", NULL);
536 if (!value)
537 return 1;
538 hi_freq = (*value) / 1000;
539 set_speed_proc = pmu_set_cpu_speed;
540 is_pmu_based = 1;
541
542 return 0;
543}
544
545static int pmac_cpufreq_init_7447A(struct device_node *cpunode)
546{
547 struct device_node *volt_gpio_np;
548
549 if (of_get_property(cpunode, "dynamic-power-step", NULL) == NULL)
550 return 1;
551
552 volt_gpio_np = of_find_node_by_name(NULL, "cpu-vcore-select");
553 if (volt_gpio_np)
554 voltage_gpio = read_gpio(volt_gpio_np);
555 if (!voltage_gpio){
556 pr_err("missing cpu-vcore-select gpio\n");
557 return 1;
558 }
559
560 /* OF only reports the high frequency */
561 hi_freq = cur_freq;
562 low_freq = cur_freq/2;
563
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;
568
569 return 0;
570}
571
572static int pmac_cpufreq_init_750FX(struct device_node *cpunode)
573{
574 struct device_node *volt_gpio_np;
575 u32 pvr;
576 const u32 *value;
577
578 if (of_get_property(cpunode, "dynamic-power-step", NULL) == NULL)
579 return 1;
580
581 hi_freq = cur_freq;
582 value = of_get_property(cpunode, "reduced-clock-frequency", NULL);
583 if (!value)
584 return 1;
585 low_freq = (*value) / 1000;
586
587 volt_gpio_np = of_find_node_by_name(NULL, "cpu-vcore-select");
588 if (volt_gpio_np)
589 voltage_gpio = read_gpio(volt_gpio_np);
590
591 pvr = mfspr(SPRN_PVR);
592 has_cpu_l2lve = !((pvr & 0xf00) == 0x100);
593
594 set_speed_proc = cpu_750fx_cpu_speed;
595 get_speed_proc = cpu_750fx_get_cpu_speed;
596 cur_freq = cpu_750fx_get_cpu_speed();
597
598 return 0;
599}
600
601/* Currently, we support the following machines:
602 *
603 * - Titanium PowerBook 1Ghz (PMU based, 667Mhz & 1Ghz)
604 * - Titanium PowerBook 800 (PMU based, 667Mhz & 800Mhz)
605 * - Titanium PowerBook 400 (PMU based, 300Mhz & 400Mhz)
606 * - Titanium PowerBook 500 (PMU based, 300Mhz & 500Mhz)
607 * - iBook2 500/600 (PMU based, 400Mhz & 500/600Mhz)
608 * - iBook2 700 (CPU based, 400Mhz & 700Mhz, support low voltage)
609 * - Recent MacRISC3 laptops
610 * - All new machines with 7447A CPUs
611 */
612static int __init pmac_cpufreq_setup(void)
613{
614 struct device_node *cpunode;
615 const u32 *value;
616
617 if (strstr(boot_command_line, "nocpufreq"))
618 return 0;
619
620 /* Get first CPU node */
621 cpunode = of_cpu_device_node_get(0);
622 if (!cpunode)
623 goto out;
624
625 /* Get current cpu clock freq */
626 value = of_get_property(cpunode, "clock-frequency", NULL);
627 if (!value)
628 goto out;
629 cur_freq = (*value) / 1000;
630
631 /* Check for 7447A based MacRISC3 */
632 if (of_machine_is_compatible("MacRISC3") &&
633 of_get_property(cpunode, "dynamic-power-step", NULL) &&
634 PVR_VER(mfspr(SPRN_PVR)) == 0x8003) {
635 pmac_cpufreq_init_7447A(cpunode);
636
637 /* Allow dynamic switching */
638 transition_latency = 8000000;
639 pmac_cpufreq_driver.flags &= ~CPUFREQ_NO_AUTO_DYNAMIC_SWITCHING;
640 /* Check for other MacRISC3 machines */
641 } else if (of_machine_is_compatible("PowerBook3,4") ||
642 of_machine_is_compatible("PowerBook3,5") ||
643 of_machine_is_compatible("MacRISC3")) {
644 pmac_cpufreq_init_MacRISC3(cpunode);
645 /* Else check for iBook2 500/600 */
646 } else if (of_machine_is_compatible("PowerBook4,1")) {
647 hi_freq = cur_freq;
648 low_freq = 400000;
649 set_speed_proc = pmu_set_cpu_speed;
650 is_pmu_based = 1;
651 }
652 /* Else check for TiPb 550 */
653 else if (of_machine_is_compatible("PowerBook3,3") && cur_freq == 550000) {
654 hi_freq = cur_freq;
655 low_freq = 500000;
656 set_speed_proc = pmu_set_cpu_speed;
657 is_pmu_based = 1;
658 }
659 /* Else check for TiPb 400 & 500 */
660 else if (of_machine_is_compatible("PowerBook3,2")) {
661 /* We only know about the 400 MHz and the 500Mhz model
662 * they both have 300 MHz as low frequency
663 */
664 if (cur_freq < 350000 || cur_freq > 550000)
665 goto out;
666 hi_freq = cur_freq;
667 low_freq = 300000;
668 set_speed_proc = pmu_set_cpu_speed;
669 is_pmu_based = 1;
670 }
671 /* Else check for 750FX */
672 else if (PVR_VER(mfspr(SPRN_PVR)) == 0x7000)
673 pmac_cpufreq_init_750FX(cpunode);
674out:
675 of_node_put(cpunode);
676 if (set_speed_proc == NULL)
677 return -ENODEV;
678
679 pmac_cpu_freqs[CPUFREQ_LOW].frequency = low_freq;
680 pmac_cpu_freqs[CPUFREQ_HIGH].frequency = hi_freq;
681 ppc_proc_freq = cur_freq * 1000ul;
682
683 pr_info("Registering PowerMac CPU frequency driver\n");
684 pr_info("Low: %d Mhz, High: %d Mhz, Boot: %d Mhz\n",
685 low_freq/1000, hi_freq/1000, cur_freq/1000);
686
687 return cpufreq_register_driver(&pmac_cpufreq_driver);
688}
689
690module_init(pmac_cpufreq_setup);
691