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>
26 #include <linux/of_device.h>
28 #include <asm/machdep.h>
30 #include <asm/pmac_feature.h>
31 #include <asm/mmu_context.h>
32 #include <asm/sections.h>
33 #include <asm/cputable.h>
36 #include <asm/keylargo.h>
37 #include <asm/switch_to.h>
39 /* WARNING !!! This will cause calibrate_delay() to be called,
40 * but this is an __init function ! So you MUST go edit
41 * init/main.c to make it non-init before enabling DEBUG_FREQ
45 extern void low_choose_7447a_dfs(int dfs);
46 extern void low_choose_750fx_pll(int pll);
47 extern void low_sleep_handler(void);
50 * Currently, PowerMac cpufreq supports only high & low frequencies
51 * that are set by the firmware
53 static unsigned int low_freq;
54 static unsigned int hi_freq;
55 static unsigned int cur_freq;
56 static unsigned int sleep_freq;
57 static unsigned long transition_latency;
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, 0, CPUFREQ_TABLE_END},
87 static inline void local_delay(unsigned long ms)
96 static inline void debug_calc_bogomips(void)
98 /* This will cause a recalc of bogomips and display the
99 * result. We backup/restore the value to avoid affecting the
100 * core cpufreq framework's own calculation.
102 unsigned long save_lpj = loops_per_jiffy;
104 loops_per_jiffy = save_lpj;
106 #endif /* DEBUG_FREQ */
108 /* Switch CPU speed under 750FX CPU control
110 static int cpu_750fx_cpu_speed(int low_speed)
114 if (low_speed == 0) {
115 /* ramping up, set voltage first */
116 pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, voltage_gpio, 0x05);
117 /* Make sure we sleep for at least 1ms */
120 /* tweak L2 for high voltage */
122 hid2 = mfspr(SPRN_HID2);
124 mtspr(SPRN_HID2, hid2);
127 #ifdef CONFIG_PPC_BOOK3S_32
128 low_choose_750fx_pll(low_speed);
130 if (low_speed == 1) {
131 /* tweak L2 for low voltage */
133 hid2 = mfspr(SPRN_HID2);
135 mtspr(SPRN_HID2, hid2);
138 /* ramping down, set voltage last */
139 pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, voltage_gpio, 0x04);
146 static unsigned int cpu_750fx_get_cpu_speed(void)
148 if (mfspr(SPRN_HID1) & HID1_PS)
154 /* Switch CPU speed using DFS */
155 static int dfs_set_cpu_speed(int low_speed)
157 if (low_speed == 0) {
158 /* ramping up, set voltage first */
159 pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, voltage_gpio, 0x05);
160 /* Make sure we sleep for at least 1ms */
165 #ifdef CONFIG_PPC_BOOK3S_32
166 low_choose_7447a_dfs(low_speed);
170 if (low_speed == 1) {
171 /* ramping down, set voltage last */
172 pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, voltage_gpio, 0x04);
179 static unsigned int dfs_get_cpu_speed(void)
181 if (mfspr(SPRN_HID1) & HID1_DFS)
188 /* Switch CPU speed using slewing GPIOs
190 static int gpios_set_cpu_speed(int low_speed)
192 int gpio, timeout = 0;
194 /* If ramping up, set voltage first */
195 if (low_speed == 0) {
196 pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, voltage_gpio, 0x05);
197 /* Delay is way too big but it's ok, we schedule */
202 gpio = pmac_call_feature(PMAC_FTR_READ_GPIO, NULL, frequency_gpio, 0);
203 if (low_speed == ((gpio & 0x01) == 0))
206 pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, frequency_gpio,
207 low_speed ? 0x04 : 0x05);
213 gpio = pmac_call_feature(PMAC_FTR_READ_GPIO, NULL, slew_done_gpio, 0);
214 } while((gpio & 0x02) == 0);
216 /* If ramping down, set voltage last */
217 if (low_speed == 1) {
218 pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, voltage_gpio, 0x04);
219 /* Delay is way too big but it's ok, we schedule */
224 debug_calc_bogomips();
230 /* Switch CPU speed under PMU control
232 static int pmu_set_cpu_speed(int low_speed)
234 struct adb_request req;
235 unsigned long save_l2cr;
236 unsigned long save_l3cr;
237 unsigned int pic_prio;
243 printk(KERN_DEBUG "HID1, before: %x\n", mfspr(SPRN_HID1));
247 /* Disable all interrupt sources on openpic */
248 pic_prio = mpic_cpu_get_priority();
249 mpic_cpu_set_priority(0xf);
251 /* Make sure the decrementer won't interrupt us */
252 asm volatile("mtdec %0" : : "r" (0x7fffffff));
253 /* Make sure any pending DEC interrupt occurring while we did
254 * the above didn't re-enable the DEC */
256 asm volatile("mtdec %0" : : "r" (0x7fffffff));
258 /* We can now disable MSR_EE */
259 local_irq_save(flags);
261 /* Giveup the FPU & vec */
264 #ifdef CONFIG_ALTIVEC
265 if (cpu_has_feature(CPU_FTR_ALTIVEC))
266 enable_kernel_altivec();
267 #endif /* CONFIG_ALTIVEC */
269 /* Save & disable L2 and L3 caches */
270 save_l3cr = _get_L3CR(); /* (returns -1 if not available) */
271 save_l2cr = _get_L2CR(); /* (returns -1 if not available) */
273 /* Send the new speed command. My assumption is that this command
274 * will cause PLL_CFG[0..3] to be changed next time CPU goes to sleep
276 pmu_request(&req, NULL, 6, PMU_CPU_SPEED, 'W', 'O', 'O', 'F', low_speed);
277 while (!req.complete)
280 /* Prepare the northbridge for the speed transition */
281 pmac_call_feature(PMAC_FTR_SLEEP_STATE,NULL,1,1);
283 /* Call low level code to backup CPU state and recover from
288 /* Restore the northbridge */
289 pmac_call_feature(PMAC_FTR_SLEEP_STATE,NULL,1,0);
291 /* Restore L2 cache */
292 if (save_l2cr != 0xffffffff && (save_l2cr & L2CR_L2E) != 0)
293 _set_L2CR(save_l2cr);
294 /* Restore L3 cache */
295 if (save_l3cr != 0xffffffff && (save_l3cr & L3CR_L3E) != 0)
296 _set_L3CR(save_l3cr);
298 /* Restore userland MMU context */
299 switch_mmu_context(NULL, current->active_mm, NULL);
302 printk(KERN_DEBUG "HID1, after: %x\n", mfspr(SPRN_HID1));
305 /* Restore low level PMU operations */
309 * Restore decrementer; we'll take a decrementer interrupt
310 * as soon as interrupts are re-enabled and the generic
311 * clockevents code will reprogram it with the right value.
315 /* Restore interrupts */
316 mpic_cpu_set_priority(pic_prio);
318 /* Let interrupts flow again ... */
319 local_irq_restore(flags);
322 debug_calc_bogomips();
332 static int do_set_cpu_speed(struct cpufreq_policy *policy, int speed_mode)
335 static unsigned long prev_l3cr;
337 if (speed_mode == CPUFREQ_LOW &&
338 cpu_has_feature(CPU_FTR_L3CR)) {
340 if (l3cr & L3CR_L3E) {
345 set_speed_proc(speed_mode == CPUFREQ_LOW);
346 if (speed_mode == CPUFREQ_HIGH &&
347 cpu_has_feature(CPU_FTR_L3CR)) {
349 if ((prev_l3cr & L3CR_L3E) && l3cr != prev_l3cr)
350 _set_L3CR(prev_l3cr);
352 cur_freq = (speed_mode == CPUFREQ_HIGH) ? hi_freq : low_freq;
357 static unsigned int pmac_cpufreq_get_speed(unsigned int cpu)
362 static int pmac_cpufreq_target( struct cpufreq_policy *policy,
367 rc = do_set_cpu_speed(policy, index);
369 ppc_proc_freq = cur_freq * 1000ul;
373 static int pmac_cpufreq_cpu_init(struct cpufreq_policy *policy)
375 cpufreq_generic_init(policy, pmac_cpu_freqs, transition_latency);
379 static u32 read_gpio(struct device_node *np)
381 const u32 *reg = of_get_property(np, "reg", NULL);
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.
393 if (offset < KEYLARGO_GPIO_LEVELS0)
394 offset += KEYLARGO_GPIO_LEVELS0;
398 static int pmac_cpufreq_suspend(struct cpufreq_policy *policy)
400 /* Ok, this could be made a bit smarter, but let's be robust for now. We
401 * always force a speed change to high speed before sleep, to make sure
402 * we have appropriate voltage and/or bus speed for the wakeup process,
403 * and to make sure our loops_per_jiffies are "good enough", that is will
404 * not cause too short delays if we sleep in low speed and wake in high
408 sleep_freq = cur_freq;
409 if (cur_freq == low_freq && !is_pmu_based)
410 do_set_cpu_speed(policy, CPUFREQ_HIGH);
414 static int pmac_cpufreq_resume(struct cpufreq_policy *policy)
416 /* If we resume, first check if we have a get() function */
418 cur_freq = get_speed_proc();
422 /* We don't, hrm... we don't really know our speed here, best
423 * is that we force a switch to whatever it was, which is
424 * probably high speed due to our suspend() routine
426 do_set_cpu_speed(policy, sleep_freq == low_freq ?
427 CPUFREQ_LOW : CPUFREQ_HIGH);
429 ppc_proc_freq = cur_freq * 1000ul;
435 static struct cpufreq_driver pmac_cpufreq_driver = {
436 .verify = cpufreq_generic_frequency_table_verify,
437 .target_index = pmac_cpufreq_target,
438 .get = pmac_cpufreq_get_speed,
439 .init = pmac_cpufreq_cpu_init,
440 .suspend = pmac_cpufreq_suspend,
441 .resume = pmac_cpufreq_resume,
442 .flags = CPUFREQ_NO_AUTO_DYNAMIC_SWITCHING,
443 .attr = cpufreq_generic_attr,
448 static int pmac_cpufreq_init_MacRISC3(struct device_node *cpunode)
450 struct device_node *volt_gpio_np = of_find_node_by_name(NULL,
452 struct device_node *freq_gpio_np = of_find_node_by_name(NULL,
454 struct device_node *slew_done_gpio_np = of_find_node_by_name(NULL,
459 * Check to see if it's GPIO driven or PMU only
461 * The way we extract the GPIO address is slightly hackish, but it
462 * works well enough for now. We need to abstract the whole GPIO
463 * stuff sooner or later anyway
467 voltage_gpio = read_gpio(volt_gpio_np);
469 frequency_gpio = read_gpio(freq_gpio_np);
470 if (slew_done_gpio_np)
471 slew_done_gpio = read_gpio(slew_done_gpio_np);
473 /* If we use the frequency GPIOs, calculate the min/max speeds based
474 * on the bus frequencies
476 if (frequency_gpio && slew_done_gpio) {
478 const u32 *freqs, *ratio;
480 freqs = of_get_property(cpunode, "bus-frequencies", &lenp);
482 if (freqs == NULL || lenp != 2) {
483 pr_err("bus-frequencies incorrect or missing\n");
486 ratio = of_get_property(cpunode, "processor-to-bus-ratio*2",
489 pr_err("processor-to-bus-ratio*2 missing\n");
493 /* Get the min/max bus frequencies */
494 low_freq = min(freqs[0], freqs[1]);
495 hi_freq = max(freqs[0], freqs[1]);
497 /* Grrrr.. It _seems_ that the device-tree is lying on the low bus
498 * frequency, it claims it to be around 84Mhz on some models while
499 * it appears to be approx. 101Mhz on all. Let's hack around here...
500 * fortunately, we don't need to be too precise
502 if (low_freq < 98000000)
503 low_freq = 101000000;
505 /* Convert those to CPU core clocks */
506 low_freq = (low_freq * (*ratio)) / 2000;
507 hi_freq = (hi_freq * (*ratio)) / 2000;
509 /* Now we get the frequencies, we read the GPIO to see what is out current
512 rc = pmac_call_feature(PMAC_FTR_READ_GPIO, NULL, frequency_gpio, 0);
513 cur_freq = (rc & 0x01) ? hi_freq : low_freq;
515 set_speed_proc = gpios_set_cpu_speed;
519 /* If we use the PMU, look for the min & max frequencies in the
522 value = of_get_property(cpunode, "min-clock-frequency", NULL);
525 low_freq = (*value) / 1000;
526 /* The PowerBook G4 12" (PowerBook6,1) has an error in the device-tree
528 if (low_freq < 100000)
531 value = of_get_property(cpunode, "max-clock-frequency", NULL);
534 hi_freq = (*value) / 1000;
535 set_speed_proc = pmu_set_cpu_speed;
541 static int pmac_cpufreq_init_7447A(struct device_node *cpunode)
543 struct device_node *volt_gpio_np;
545 if (of_get_property(cpunode, "dynamic-power-step", NULL) == NULL)
548 volt_gpio_np = of_find_node_by_name(NULL, "cpu-vcore-select");
550 voltage_gpio = read_gpio(volt_gpio_np);
551 of_node_put(volt_gpio_np);
553 pr_err("missing cpu-vcore-select gpio\n");
557 /* OF only reports the high frequency */
559 low_freq = cur_freq/2;
561 /* Read actual frequency from CPU */
562 cur_freq = dfs_get_cpu_speed();
563 set_speed_proc = dfs_set_cpu_speed;
564 get_speed_proc = dfs_get_cpu_speed;
569 static int pmac_cpufreq_init_750FX(struct device_node *cpunode)
571 struct device_node *volt_gpio_np;
575 if (of_get_property(cpunode, "dynamic-power-step", NULL) == NULL)
579 value = of_get_property(cpunode, "reduced-clock-frequency", NULL);
582 low_freq = (*value) / 1000;
584 volt_gpio_np = of_find_node_by_name(NULL, "cpu-vcore-select");
586 voltage_gpio = read_gpio(volt_gpio_np);
588 of_node_put(volt_gpio_np);
589 pvr = mfspr(SPRN_PVR);
590 has_cpu_l2lve = !((pvr & 0xf00) == 0x100);
592 set_speed_proc = cpu_750fx_cpu_speed;
593 get_speed_proc = cpu_750fx_get_cpu_speed;
594 cur_freq = cpu_750fx_get_cpu_speed();
599 /* Currently, we support the following machines:
601 * - Titanium PowerBook 1Ghz (PMU based, 667Mhz & 1Ghz)
602 * - Titanium PowerBook 800 (PMU based, 667Mhz & 800Mhz)
603 * - Titanium PowerBook 400 (PMU based, 300Mhz & 400Mhz)
604 * - Titanium PowerBook 500 (PMU based, 300Mhz & 500Mhz)
605 * - iBook2 500/600 (PMU based, 400Mhz & 500/600Mhz)
606 * - iBook2 700 (CPU based, 400Mhz & 700Mhz, support low voltage)
607 * - Recent MacRISC3 laptops
608 * - All new machines with 7447A CPUs
610 static int __init pmac_cpufreq_setup(void)
612 struct device_node *cpunode;
615 if (strstr(boot_command_line, "nocpufreq"))
618 /* Get first CPU node */
619 cpunode = of_cpu_device_node_get(0);
623 /* Get current cpu clock freq */
624 value = of_get_property(cpunode, "clock-frequency", NULL);
627 cur_freq = (*value) / 1000;
629 /* Check for 7447A based MacRISC3 */
630 if (of_machine_is_compatible("MacRISC3") &&
631 of_get_property(cpunode, "dynamic-power-step", NULL) &&
632 PVR_VER(mfspr(SPRN_PVR)) == 0x8003) {
633 pmac_cpufreq_init_7447A(cpunode);
635 /* Allow dynamic switching */
636 transition_latency = 8000000;
637 pmac_cpufreq_driver.flags &= ~CPUFREQ_NO_AUTO_DYNAMIC_SWITCHING;
638 /* Check for other MacRISC3 machines */
639 } else if (of_machine_is_compatible("PowerBook3,4") ||
640 of_machine_is_compatible("PowerBook3,5") ||
641 of_machine_is_compatible("MacRISC3")) {
642 pmac_cpufreq_init_MacRISC3(cpunode);
643 /* Else check for iBook2 500/600 */
644 } else if (of_machine_is_compatible("PowerBook4,1")) {
647 set_speed_proc = pmu_set_cpu_speed;
650 /* Else check for TiPb 550 */
651 else if (of_machine_is_compatible("PowerBook3,3") && cur_freq == 550000) {
654 set_speed_proc = pmu_set_cpu_speed;
657 /* Else check for TiPb 400 & 500 */
658 else if (of_machine_is_compatible("PowerBook3,2")) {
659 /* We only know about the 400 MHz and the 500Mhz model
660 * they both have 300 MHz as low frequency
662 if (cur_freq < 350000 || cur_freq > 550000)
666 set_speed_proc = pmu_set_cpu_speed;
669 /* Else check for 750FX */
670 else if (PVR_VER(mfspr(SPRN_PVR)) == 0x7000)
671 pmac_cpufreq_init_750FX(cpunode);
673 of_node_put(cpunode);
674 if (set_speed_proc == NULL)
677 pmac_cpu_freqs[CPUFREQ_LOW].frequency = low_freq;
678 pmac_cpu_freqs[CPUFREQ_HIGH].frequency = hi_freq;
679 ppc_proc_freq = cur_freq * 1000ul;
681 pr_info("Registering PowerMac CPU frequency driver\n");
682 pr_info("Low: %d Mhz, High: %d Mhz, Boot: %d Mhz\n",
683 low_freq/1000, hi_freq/1000, cur_freq/1000);
685 return cpufreq_register_driver(&pmac_cpufreq_driver);
688 module_init(pmac_cpufreq_setup);