xref: /openbmc/linux/drivers/cpufreq/speedstep-lib.h (revision 75bf465f0bc33e9b776a46d6a1b9b990f5fb7c37)
1*4f19048fSThomas Gleixner /* SPDX-License-Identifier: GPL-2.0-only */
2bb0a56ecSDave Jones /*
3bb0a56ecSDave Jones  * (C) 2002 - 2003 Dominik Brodowski <linux@brodo.de>
4bb0a56ecSDave Jones  *
5bb0a56ecSDave Jones  *  Library for common functions for Intel SpeedStep v.1 and v.2 support
6bb0a56ecSDave Jones  *
7bb0a56ecSDave Jones  *  BIG FAT DISCLAIMER: Work in progress code. Possibly *dangerous*
8bb0a56ecSDave Jones  */
9bb0a56ecSDave Jones 
10bb0a56ecSDave Jones 
11bb0a56ecSDave Jones 
12bb0a56ecSDave Jones /* processors */
13bb0a56ecSDave Jones enum speedstep_processor {
14bb0a56ecSDave Jones 	SPEEDSTEP_CPU_PIII_C_EARLY = 0x00000001,  /* Coppermine core */
15bb0a56ecSDave Jones 	SPEEDSTEP_CPU_PIII_C	   = 0x00000002,  /* Coppermine core */
16bb0a56ecSDave Jones 	SPEEDSTEP_CPU_PIII_T	   = 0x00000003,  /* Tualatin core */
17bb0a56ecSDave Jones 	SPEEDSTEP_CPU_P4M	   = 0x00000004,  /* P4-M  */
18bb0a56ecSDave Jones /* the following processors are not speedstep-capable and are not auto-detected
19bb0a56ecSDave Jones  * in speedstep_detect_processor(). However, their speed can be detected using
20bb0a56ecSDave Jones  * the speedstep_get_frequency() call. */
21bb0a56ecSDave Jones 	SPEEDSTEP_CPU_PM	   = 0xFFFFFF03,  /* Pentium M  */
22bb0a56ecSDave Jones 	SPEEDSTEP_CPU_P4D	   = 0xFFFFFF04,  /* desktop P4  */
23bb0a56ecSDave Jones 	SPEEDSTEP_CPU_PCORE	   = 0xFFFFFF05,  /* Core */
24bb0a56ecSDave Jones };
25bb0a56ecSDave Jones 
26bb0a56ecSDave Jones /* speedstep states -- only two of them */
27bb0a56ecSDave Jones 
28bb0a56ecSDave Jones #define SPEEDSTEP_HIGH	0x00000000
29bb0a56ecSDave Jones #define SPEEDSTEP_LOW	0x00000001
30bb0a56ecSDave Jones 
31bb0a56ecSDave Jones 
32bb0a56ecSDave Jones /* detect a speedstep-capable processor */
33bb0a56ecSDave Jones extern enum speedstep_processor speedstep_detect_processor(void);
34bb0a56ecSDave Jones 
35bb0a56ecSDave Jones /* detect the current speed (in khz) of the processor */
36bb0a56ecSDave Jones extern unsigned int speedstep_get_frequency(enum speedstep_processor processor);
37bb0a56ecSDave Jones 
38bb0a56ecSDave Jones 
39bb0a56ecSDave Jones /* detect the low and high speeds of the processor. The callback
40bb0a56ecSDave Jones  * set_state"'s first argument is either SPEEDSTEP_HIGH or
41bb0a56ecSDave Jones  * SPEEDSTEP_LOW; the second argument is zero so that no
42bb0a56ecSDave Jones  * cpufreq_notify_transition calls are initiated.
43bb0a56ecSDave Jones  */
44bb0a56ecSDave Jones extern unsigned int speedstep_get_freqs(enum speedstep_processor processor,
45bb0a56ecSDave Jones 	unsigned int *low_speed,
46bb0a56ecSDave Jones 	unsigned int *high_speed,
47bb0a56ecSDave Jones 	unsigned int *transition_latency,
48bb0a56ecSDave Jones 	void (*set_state) (unsigned int state));
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