2 * Copyright (C) 2002 - 2005 Benjamin Herrenschmidt <benh@kernel.crashing.org>
3 * and Markus Demleitner <msdemlei@cl.uni-heidelberg.de>
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 * This driver adds basic cpufreq support for SMU & 970FX based G5 Macs,
10 * that is iMac G5 and latest single CPU desktop.
15 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
17 #include <linux/module.h>
18 #include <linux/types.h>
19 #include <linux/errno.h>
20 #include <linux/kernel.h>
21 #include <linux/delay.h>
22 #include <linux/sched.h>
23 #include <linux/cpufreq.h>
24 #include <linux/init.h>
25 #include <linux/completion.h>
26 #include <linux/mutex.h>
27 #include <linux/of_device.h>
29 #include <asm/machdep.h>
31 #include <asm/sections.h>
32 #include <asm/cputable.h>
35 #include <asm/pmac_pfunc.h>
37 #define DBG(fmt...) pr_debug(fmt)
39 /* see 970FX user manual */
41 #define SCOM_PCR 0x0aa001 /* PCR scom addr */
43 #define PCR_HILO_SELECT 0x80000000U /* 1 = PCR, 0 = PCRH */
44 #define PCR_SPEED_FULL 0x00000000U /* 1:1 speed value */
45 #define PCR_SPEED_HALF 0x00020000U /* 1:2 speed value */
46 #define PCR_SPEED_QUARTER 0x00040000U /* 1:4 speed value */
47 #define PCR_SPEED_MASK 0x000e0000U /* speed mask */
48 #define PCR_SPEED_SHIFT 17
49 #define PCR_FREQ_REQ_VALID 0x00010000U /* freq request valid */
50 #define PCR_VOLT_REQ_VALID 0x00008000U /* volt request valid */
51 #define PCR_TARGET_TIME_MASK 0x00006000U /* target time */
52 #define PCR_STATLAT_MASK 0x00001f00U /* STATLAT value */
53 #define PCR_SNOOPLAT_MASK 0x000000f0U /* SNOOPLAT value */
54 #define PCR_SNOOPACC_MASK 0x0000000fU /* SNOOPACC value */
56 #define SCOM_PSR 0x408001 /* PSR scom addr */
57 /* warning: PSR is a 64 bits register */
58 #define PSR_CMD_RECEIVED 0x2000000000000000U /* command received */
59 #define PSR_CMD_COMPLETED 0x1000000000000000U /* command completed */
60 #define PSR_CUR_SPEED_MASK 0x0300000000000000U /* current speed */
61 #define PSR_CUR_SPEED_SHIFT (56)
64 * The G5 only supports two frequencies (Quarter speed is not supported)
66 #define CPUFREQ_HIGH 0
69 static struct cpufreq_frequency_table g5_cpu_freqs
[] = {
72 {0, 0, CPUFREQ_TABLE_END
},
75 /* Power mode data is an array of the 32 bits PCR values to use for
76 * the various frequencies, retrieved from the device-tree
78 static int g5_pmode_cur
;
80 static void (*g5_switch_volt
)(int speed_mode
);
81 static int (*g5_switch_freq
)(int speed_mode
);
82 static int (*g5_query_freq
)(void);
84 static unsigned long transition_latency
;
86 #ifdef CONFIG_PMAC_SMU
88 static const u32
*g5_pmode_data
;
89 static int g5_pmode_max
;
91 static struct smu_sdbp_fvt
*g5_fvt_table
; /* table of op. points */
92 static int g5_fvt_count
; /* number of op. points */
93 static int g5_fvt_cur
; /* current op. point */
96 * SMU based voltage switching for Neo2 platforms
99 static void g5_smu_switch_volt(int speed_mode
)
101 struct smu_simple_cmd cmd
;
103 DECLARE_COMPLETION_ONSTACK(comp
);
104 smu_queue_simple(&cmd
, SMU_CMD_POWER_COMMAND
, 8, smu_done_complete
,
105 &comp
, 'V', 'S', 'L', 'E', 'W',
106 0xff, g5_fvt_cur
+1, speed_mode
);
107 wait_for_completion(&comp
);
111 * Platform function based voltage/vdnap switching for Neo2
114 static struct pmf_function
*pfunc_set_vdnap0
;
115 static struct pmf_function
*pfunc_vdnap0_complete
;
117 static void g5_vdnap_switch_volt(int speed_mode
)
119 struct pmf_args args
;
121 unsigned long timeout
;
123 slew
= (speed_mode
== CPUFREQ_LOW
) ? 1 : 0;
127 pmf_call_one(pfunc_set_vdnap0
, &args
);
129 /* It's an irq GPIO so we should be able to just block here,
130 * I'll do that later after I've properly tested the IRQ code for
133 timeout
= jiffies
+ HZ
/10;
134 while(!time_after(jiffies
, timeout
)) {
137 pmf_call_one(pfunc_vdnap0_complete
, &args
);
140 usleep_range(1000, 1000);
143 pr_warn("Timeout in clock slewing !\n");
148 * SCOM based frequency switching for 970FX rev3
150 static int g5_scom_switch_freq(int speed_mode
)
155 /* If frequency is going up, first ramp up the voltage */
156 if (speed_mode
< g5_pmode_cur
)
157 g5_switch_volt(speed_mode
);
159 local_irq_save(flags
);
162 scom970_write(SCOM_PCR
, 0);
164 scom970_write(SCOM_PCR
, PCR_HILO_SELECT
| 0);
166 scom970_write(SCOM_PCR
, PCR_HILO_SELECT
|
167 g5_pmode_data
[speed_mode
]);
169 /* Wait for completion */
170 for (to
= 0; to
< 10; to
++) {
171 unsigned long psr
= scom970_read(SCOM_PSR
);
173 if ((psr
& PSR_CMD_RECEIVED
) == 0 &&
174 (((psr
>> PSR_CUR_SPEED_SHIFT
) ^
175 (g5_pmode_data
[speed_mode
] >> PCR_SPEED_SHIFT
)) & 0x3)
178 if (psr
& PSR_CMD_COMPLETED
)
183 local_irq_restore(flags
);
185 /* If frequency is going down, last ramp the voltage */
186 if (speed_mode
> g5_pmode_cur
)
187 g5_switch_volt(speed_mode
);
189 g5_pmode_cur
= speed_mode
;
190 ppc_proc_freq
= g5_cpu_freqs
[speed_mode
].frequency
* 1000ul;
195 static int g5_scom_query_freq(void)
197 unsigned long psr
= scom970_read(SCOM_PSR
);
200 for (i
= 0; i
<= g5_pmode_max
; i
++)
201 if ((((psr
>> PSR_CUR_SPEED_SHIFT
) ^
202 (g5_pmode_data
[i
] >> PCR_SPEED_SHIFT
)) & 0x3) == 0)
208 * Fake voltage switching for platforms with missing support
211 static void g5_dummy_switch_volt(int speed_mode
)
215 #endif /* CONFIG_PMAC_SMU */
218 * Platform function based voltage switching for PowerMac7,2 & 7,3
221 static struct pmf_function
*pfunc_cpu0_volt_high
;
222 static struct pmf_function
*pfunc_cpu0_volt_low
;
223 static struct pmf_function
*pfunc_cpu1_volt_high
;
224 static struct pmf_function
*pfunc_cpu1_volt_low
;
226 static void g5_pfunc_switch_volt(int speed_mode
)
228 if (speed_mode
== CPUFREQ_HIGH
) {
229 if (pfunc_cpu0_volt_high
)
230 pmf_call_one(pfunc_cpu0_volt_high
, NULL
);
231 if (pfunc_cpu1_volt_high
)
232 pmf_call_one(pfunc_cpu1_volt_high
, NULL
);
234 if (pfunc_cpu0_volt_low
)
235 pmf_call_one(pfunc_cpu0_volt_low
, NULL
);
236 if (pfunc_cpu1_volt_low
)
237 pmf_call_one(pfunc_cpu1_volt_low
, NULL
);
239 usleep_range(10000, 10000); /* should be faster , to fix */
243 * Platform function based frequency switching for PowerMac7,2 & 7,3
246 static struct pmf_function
*pfunc_cpu_setfreq_high
;
247 static struct pmf_function
*pfunc_cpu_setfreq_low
;
248 static struct pmf_function
*pfunc_cpu_getfreq
;
249 static struct pmf_function
*pfunc_slewing_done
;
251 static int g5_pfunc_switch_freq(int speed_mode
)
253 struct pmf_args args
;
255 unsigned long timeout
;
258 DBG("g5_pfunc_switch_freq(%d)\n", speed_mode
);
260 /* If frequency is going up, first ramp up the voltage */
261 if (speed_mode
< g5_pmode_cur
)
262 g5_switch_volt(speed_mode
);
265 if (speed_mode
== CPUFREQ_HIGH
)
266 rc
= pmf_call_one(pfunc_cpu_setfreq_high
, NULL
);
268 rc
= pmf_call_one(pfunc_cpu_setfreq_low
, NULL
);
271 pr_warn("pfunc switch error %d\n", rc
);
273 /* It's an irq GPIO so we should be able to just block here,
274 * I'll do that later after I've properly tested the IRQ code for
277 timeout
= jiffies
+ HZ
/10;
278 while(!time_after(jiffies
, timeout
)) {
281 pmf_call_one(pfunc_slewing_done
, &args
);
284 usleep_range(500, 500);
287 pr_warn("Timeout in clock slewing !\n");
289 /* If frequency is going down, last ramp the voltage */
290 if (speed_mode
> g5_pmode_cur
)
291 g5_switch_volt(speed_mode
);
293 g5_pmode_cur
= speed_mode
;
294 ppc_proc_freq
= g5_cpu_freqs
[speed_mode
].frequency
* 1000ul;
299 static int g5_pfunc_query_freq(void)
301 struct pmf_args args
;
306 pmf_call_one(pfunc_cpu_getfreq
, &args
);
307 return val
? CPUFREQ_HIGH
: CPUFREQ_LOW
;
312 * Common interface to the cpufreq core
315 static int g5_cpufreq_target(struct cpufreq_policy
*policy
, unsigned int index
)
317 return g5_switch_freq(index
);
320 static unsigned int g5_cpufreq_get_speed(unsigned int cpu
)
322 return g5_cpu_freqs
[g5_pmode_cur
].frequency
;
325 static int g5_cpufreq_cpu_init(struct cpufreq_policy
*policy
)
327 return cpufreq_generic_init(policy
, g5_cpu_freqs
, transition_latency
);
330 static struct cpufreq_driver g5_cpufreq_driver
= {
332 .flags
= CPUFREQ_CONST_LOOPS
,
333 .init
= g5_cpufreq_cpu_init
,
334 .verify
= cpufreq_generic_frequency_table_verify
,
335 .target_index
= g5_cpufreq_target
,
336 .get
= g5_cpufreq_get_speed
,
337 .attr
= cpufreq_generic_attr
,
341 #ifdef CONFIG_PMAC_SMU
343 static int __init
g5_neo2_cpufreq_init(struct device_node
*cpunode
)
345 unsigned int psize
, ssize
;
346 unsigned long max_freq
;
347 char *freq_method
, *volt_method
;
350 int use_volts_vdnap
= 0;
351 int use_volts_smu
= 0;
354 /* Check supported platforms */
355 if (of_machine_is_compatible("PowerMac8,1") ||
356 of_machine_is_compatible("PowerMac8,2") ||
357 of_machine_is_compatible("PowerMac9,1") ||
358 of_machine_is_compatible("PowerMac12,1"))
360 else if (of_machine_is_compatible("PowerMac11,2"))
365 /* Check 970FX for now */
366 valp
= of_get_property(cpunode
, "cpu-version", NULL
);
368 DBG("No cpu-version property !\n");
371 pvr_hi
= (*valp
) >> 16;
372 if (pvr_hi
!= 0x3c && pvr_hi
!= 0x44) {
373 pr_err("Unsupported CPU version\n");
377 /* Look for the powertune data in the device-tree */
378 g5_pmode_data
= of_get_property(cpunode
, "power-mode-data",&psize
);
379 if (!g5_pmode_data
) {
380 DBG("No power-mode-data !\n");
383 g5_pmode_max
= psize
/ sizeof(u32
) - 1;
386 const struct smu_sdbp_header
*shdr
;
388 /* Look for the FVT table */
389 shdr
= smu_get_sdb_partition(SMU_SDB_FVT_ID
, NULL
);
392 g5_fvt_table
= (struct smu_sdbp_fvt
*)&shdr
[1];
393 ssize
= (shdr
->len
* sizeof(u32
)) - sizeof(*shdr
);
394 g5_fvt_count
= ssize
/ sizeof(*g5_fvt_table
);
397 /* Sanity checking */
398 if (g5_fvt_count
< 1 || g5_pmode_max
< 1)
401 g5_switch_volt
= g5_smu_switch_volt
;
403 } else if (use_volts_vdnap
) {
404 struct device_node
*root
;
406 root
= of_find_node_by_path("/");
408 pr_err("Can't find root of device tree\n");
411 pfunc_set_vdnap0
= pmf_find_function(root
, "set-vdnap0");
412 pfunc_vdnap0_complete
=
413 pmf_find_function(root
, "slewing-done");
415 if (pfunc_set_vdnap0
== NULL
||
416 pfunc_vdnap0_complete
== NULL
) {
417 pr_err("Can't find required platform function\n");
421 g5_switch_volt
= g5_vdnap_switch_volt
;
422 volt_method
= "GPIO";
424 g5_switch_volt
= g5_dummy_switch_volt
;
425 volt_method
= "none";
429 * From what I see, clock-frequency is always the maximal frequency.
430 * The current driver can not slew sysclk yet, so we really only deal
431 * with powertune steps for now. We also only implement full freq and
432 * half freq in this version. So far, I haven't yet seen a machine
433 * supporting anything else.
435 valp
= of_get_property(cpunode
, "clock-frequency", NULL
);
438 max_freq
= (*valp
)/1000;
439 g5_cpu_freqs
[0].frequency
= max_freq
;
440 g5_cpu_freqs
[1].frequency
= max_freq
/2;
443 transition_latency
= 12000;
444 g5_switch_freq
= g5_scom_switch_freq
;
445 g5_query_freq
= g5_scom_query_freq
;
446 freq_method
= "SCOM";
448 /* Force apply current frequency to make sure everything is in
449 * sync (voltage is right for example). Firmware may leave us with
450 * a strange setting ...
452 g5_switch_volt(CPUFREQ_HIGH
);
455 g5_switch_freq(g5_query_freq());
457 pr_info("Registering G5 CPU frequency driver\n");
458 pr_info("Frequency method: %s, Voltage method: %s\n",
459 freq_method
, volt_method
);
460 pr_info("Low: %d Mhz, High: %d Mhz, Cur: %d MHz\n",
461 g5_cpu_freqs
[1].frequency
/1000,
462 g5_cpu_freqs
[0].frequency
/1000,
463 g5_cpu_freqs
[g5_pmode_cur
].frequency
/1000);
465 rc
= cpufreq_register_driver(&g5_cpufreq_driver
);
467 /* We keep the CPU node on hold... hopefully, Apple G5 don't have
468 * hotplug CPU with a dynamic device-tree ...
473 of_node_put(cpunode
);
478 #endif /* CONFIG_PMAC_SMU */
481 static int __init
g5_pm72_cpufreq_init(struct device_node
*cpunode
)
483 struct device_node
*cpuid
= NULL
, *hwclock
= NULL
;
484 const u8
*eeprom
= NULL
;
486 u64 max_freq
, min_freq
, ih
, il
;
487 int has_volt
= 1, rc
= 0;
489 DBG("cpufreq: Initializing for PowerMac7,2, PowerMac7,3 and"
492 /* Lookup the cpuid eeprom node */
493 cpuid
= of_find_node_by_path("/u3@0,f8000000/i2c@f8001000/cpuid@a0");
495 eeprom
= of_get_property(cpuid
, "cpuid", NULL
);
496 if (eeprom
== NULL
) {
497 pr_err("Can't find cpuid EEPROM !\n");
502 /* Lookup the i2c hwclock */
503 for_each_node_by_name(hwclock
, "i2c-hwclock") {
504 const char *loc
= of_get_property(hwclock
,
505 "hwctrl-location", NULL
);
508 if (strcmp(loc
, "CPU CLOCK"))
510 if (!of_get_property(hwclock
, "platform-get-frequency", NULL
))
514 if (hwclock
== NULL
) {
515 pr_err("Can't find i2c clock chip !\n");
520 DBG("cpufreq: i2c clock chip found: %pOF\n", hwclock
);
522 /* Now get all the platform functions */
524 pmf_find_function(hwclock
, "get-frequency");
525 pfunc_cpu_setfreq_high
=
526 pmf_find_function(hwclock
, "set-frequency-high");
527 pfunc_cpu_setfreq_low
=
528 pmf_find_function(hwclock
, "set-frequency-low");
530 pmf_find_function(hwclock
, "slewing-done");
531 pfunc_cpu0_volt_high
=
532 pmf_find_function(hwclock
, "set-voltage-high-0");
533 pfunc_cpu0_volt_low
=
534 pmf_find_function(hwclock
, "set-voltage-low-0");
535 pfunc_cpu1_volt_high
=
536 pmf_find_function(hwclock
, "set-voltage-high-1");
537 pfunc_cpu1_volt_low
=
538 pmf_find_function(hwclock
, "set-voltage-low-1");
540 /* Check we have minimum requirements */
541 if (pfunc_cpu_getfreq
== NULL
|| pfunc_cpu_setfreq_high
== NULL
||
542 pfunc_cpu_setfreq_low
== NULL
|| pfunc_slewing_done
== NULL
) {
543 pr_err("Can't find platform functions !\n");
548 /* Check that we have complete sets */
549 if (pfunc_cpu0_volt_high
== NULL
|| pfunc_cpu0_volt_low
== NULL
) {
550 pmf_put_function(pfunc_cpu0_volt_high
);
551 pmf_put_function(pfunc_cpu0_volt_low
);
552 pfunc_cpu0_volt_high
= pfunc_cpu0_volt_low
= NULL
;
556 pfunc_cpu1_volt_high
== NULL
|| pfunc_cpu1_volt_low
== NULL
) {
557 pmf_put_function(pfunc_cpu1_volt_high
);
558 pmf_put_function(pfunc_cpu1_volt_low
);
559 pfunc_cpu1_volt_high
= pfunc_cpu1_volt_low
= NULL
;
562 /* Note: The device tree also contains a "platform-set-values"
563 * function for which I haven't quite figured out the usage. It
564 * might have to be called on init and/or wakeup, I'm not too sure
565 * but things seem to work fine without it so far ...
568 /* Get max frequency from device-tree */
569 valp
= of_get_property(cpunode
, "clock-frequency", NULL
);
571 pr_err("Can't find CPU frequency !\n");
576 max_freq
= (*valp
)/1000;
578 /* Now calculate reduced frequency by using the cpuid input freq
579 * ratio. This requires 64 bits math unless we are willing to lose
582 ih
= *((u32
*)(eeprom
+ 0x10));
583 il
= *((u32
*)(eeprom
+ 0x20));
585 /* Check for machines with no useful settings */
587 pr_warn("No low frequency mode available on this model !\n");
593 if (ih
!= 0 && il
!= 0)
594 min_freq
= (max_freq
* il
) / ih
;
597 if (min_freq
>= max_freq
|| min_freq
< 1000) {
598 pr_err("Can't calculate low frequency !\n");
602 g5_cpu_freqs
[0].frequency
= max_freq
;
603 g5_cpu_freqs
[1].frequency
= min_freq
;
605 /* Based on a measurement on Xserve G5, rounded up. */
606 transition_latency
= 10 * NSEC_PER_MSEC
;
609 g5_switch_volt
= g5_pfunc_switch_volt
;
610 g5_switch_freq
= g5_pfunc_switch_freq
;
611 g5_query_freq
= g5_pfunc_query_freq
;
613 /* Force apply current frequency to make sure everything is in
614 * sync (voltage is right for example). Firmware may leave us with
615 * a strange setting ...
617 g5_switch_volt(CPUFREQ_HIGH
);
620 g5_switch_freq(g5_query_freq());
622 pr_info("Registering G5 CPU frequency driver\n");
623 pr_info("Frequency method: i2c/pfunc, Voltage method: %s\n",
624 has_volt
? "i2c/pfunc" : "none");
625 pr_info("Low: %d Mhz, High: %d Mhz, Cur: %d MHz\n",
626 g5_cpu_freqs
[1].frequency
/1000,
627 g5_cpu_freqs
[0].frequency
/1000,
628 g5_cpu_freqs
[g5_pmode_cur
].frequency
/1000);
630 rc
= cpufreq_register_driver(&g5_cpufreq_driver
);
633 pmf_put_function(pfunc_cpu_getfreq
);
634 pmf_put_function(pfunc_cpu_setfreq_high
);
635 pmf_put_function(pfunc_cpu_setfreq_low
);
636 pmf_put_function(pfunc_slewing_done
);
637 pmf_put_function(pfunc_cpu0_volt_high
);
638 pmf_put_function(pfunc_cpu0_volt_low
);
639 pmf_put_function(pfunc_cpu1_volt_high
);
640 pmf_put_function(pfunc_cpu1_volt_low
);
642 of_node_put(hwclock
);
644 of_node_put(cpunode
);
649 static int __init
g5_cpufreq_init(void)
651 struct device_node
*cpunode
;
654 /* Get first CPU node */
655 cpunode
= of_cpu_device_node_get(0);
656 if (cpunode
== NULL
) {
657 pr_err("Can't find any CPU node\n");
661 if (of_machine_is_compatible("PowerMac7,2") ||
662 of_machine_is_compatible("PowerMac7,3") ||
663 of_machine_is_compatible("RackMac3,1"))
664 rc
= g5_pm72_cpufreq_init(cpunode
);
665 #ifdef CONFIG_PMAC_SMU
667 rc
= g5_neo2_cpufreq_init(cpunode
);
668 #endif /* CONFIG_PMAC_SMU */
673 module_init(g5_cpufreq_init
);
676 MODULE_LICENSE("GPL");