xref: /openbmc/linux/drivers/cpufreq/Kconfig.x86 (revision d7a3d85e) 
1#
2# x86 CPU Frequency scaling drivers
3#
4
5config X86_INTEL_PSTATE
6       bool "Intel P state control"
7       depends on X86
8       help
9          This driver provides a P state for Intel core processors.
10	  The driver implements an internal governor and will become
11          the scaling driver and governor for Sandy bridge processors.
12
13	  When this driver is enabled it will become the preferred
14          scaling driver for Sandy bridge processors.
15
16	  If in doubt, say N.
17
18config X86_PCC_CPUFREQ
19	tristate "Processor Clocking Control interface driver"
20	depends on ACPI && ACPI_PROCESSOR
21	help
22	  This driver adds support for the PCC interface.
23
24	  For details, take a look at:
25	  <file:Documentation/cpu-freq/pcc-cpufreq.txt>.
26
27	  To compile this driver as a module, choose M here: the
28	  module will be called pcc-cpufreq.
29
30	  If in doubt, say N.
31
32config X86_ACPI_CPUFREQ
33	tristate "ACPI Processor P-States driver"
34	depends on ACPI_PROCESSOR
35	help
36	  This driver adds a CPUFreq driver which utilizes the ACPI
37	  Processor Performance States.
38	  This driver also supports Intel Enhanced Speedstep and newer
39	  AMD CPUs.
40
41	  To compile this driver as a module, choose M here: the
42	  module will be called acpi-cpufreq.
43
44	  For details, take a look at <file:Documentation/cpu-freq/>.
45
46	  If in doubt, say N.
47
48config X86_ACPI_CPUFREQ_CPB
49	default y
50	bool "Legacy cpb sysfs knob support for AMD CPUs"
51	depends on X86_ACPI_CPUFREQ && CPU_SUP_AMD
52	help
53	  The powernow-k8 driver used to provide a sysfs knob called "cpb"
54	  to disable the Core Performance Boosting feature of AMD CPUs. This
55	  file has now been superseded by the more generic "boost" entry.
56
57	  By enabling this option the acpi_cpufreq driver provides the old
58	  entry in addition to the new boost ones, for compatibility reasons.
59
60config X86_SFI_CPUFREQ
61	tristate "SFI Performance-States driver"
62	depends on X86_INTEL_MID && SFI
63	help
64	  This adds a CPUFreq driver for some Silvermont based Intel Atom
65	  architectures like Z34xx and Z35xx which enumerate processor
66	  performance states through SFI.
67
68	  If in doubt, say N.
69
70config ELAN_CPUFREQ
71	tristate "AMD Elan SC400 and SC410"
72	depends on MELAN
73	---help---
74	  This adds the CPUFreq driver for AMD Elan SC400 and SC410
75	  processors.
76
77	  You need to specify the processor maximum speed as boot
78	  parameter: elanfreq=maxspeed (in kHz) or as module
79	  parameter "max_freq".
80
81	  For details, take a look at <file:Documentation/cpu-freq/>.
82
83	  If in doubt, say N.
84
85config SC520_CPUFREQ
86	tristate "AMD Elan SC520"
87	depends on MELAN
88	---help---
89	  This adds the CPUFreq driver for AMD Elan SC520 processor.
90
91	  For details, take a look at <file:Documentation/cpu-freq/>.
92
93	  If in doubt, say N.
94
95
96config X86_POWERNOW_K6
97	tristate "AMD Mobile K6-2/K6-3 PowerNow!"
98	depends on X86_32
99	help
100	  This adds the CPUFreq driver for mobile AMD K6-2+ and mobile
101	  AMD K6-3+ processors.
102
103	  For details, take a look at <file:Documentation/cpu-freq/>.
104
105	  If in doubt, say N.
106
107config X86_POWERNOW_K7
108	tristate "AMD Mobile Athlon/Duron PowerNow!"
109	depends on X86_32
110	help
111	  This adds the CPUFreq driver for mobile AMD K7 mobile processors.
112
113	  For details, take a look at <file:Documentation/cpu-freq/>.
114
115	  If in doubt, say N.
116
117config X86_POWERNOW_K7_ACPI
118	bool
119	depends on X86_POWERNOW_K7 && ACPI_PROCESSOR
120	depends on !(X86_POWERNOW_K7 = y && ACPI_PROCESSOR = m)
121	depends on X86_32
122	default y
123
124config X86_POWERNOW_K8
125	tristate "AMD Opteron/Athlon64 PowerNow!"
126	depends on ACPI && ACPI_PROCESSOR && X86_ACPI_CPUFREQ
127	help
128	  This adds the CPUFreq driver for K8/early Opteron/Athlon64 processors.
129	  Support for K10 and newer processors is now in acpi-cpufreq.
130
131	  To compile this driver as a module, choose M here: the
132	  module will be called powernow-k8.
133
134	  For details, take a look at <file:Documentation/cpu-freq/>.
135
136config X86_AMD_FREQ_SENSITIVITY
137	tristate "AMD frequency sensitivity feedback powersave bias"
138	depends on CPU_FREQ_GOV_ONDEMAND && X86_ACPI_CPUFREQ && CPU_SUP_AMD
139	help
140	  This adds AMD-specific powersave bias function to the ondemand
141	  governor, which allows it to make more power-conscious frequency
142	  change decisions based on feedback from hardware (available on AMD
143	  Family 16h and above).
144
145	  Hardware feedback tells software how "sensitive" to frequency changes
146	  the CPUs' workloads are. CPU-bound workloads will be more sensitive
147	  -- they will perform better as frequency increases. Memory/IO-bound
148	  workloads will be less sensitive -- they will not necessarily perform
149	  better as frequency increases.
150
151	  If in doubt, say N.
152
153config X86_GX_SUSPMOD
154	tristate "Cyrix MediaGX/NatSemi Geode Suspend Modulation"
155	depends on X86_32 && PCI
156	help
157	 This add the CPUFreq driver for NatSemi Geode processors which
158	 support suspend modulation.
159
160	 For details, take a look at <file:Documentation/cpu-freq/>.
161
162	 If in doubt, say N.
163
164config X86_SPEEDSTEP_CENTRINO
165	tristate "Intel Enhanced SpeedStep (deprecated)"
166	select X86_SPEEDSTEP_CENTRINO_TABLE if X86_32
167	depends on X86_32 || (X86_64 && ACPI_PROCESSOR)
168	help
169	  This is deprecated and this functionality is now merged into
170	  acpi_cpufreq (X86_ACPI_CPUFREQ). Use that driver instead of
171	  speedstep_centrino.
172	  This adds the CPUFreq driver for Enhanced SpeedStep enabled
173	  mobile CPUs.  This means Intel Pentium M (Centrino) CPUs
174	  or 64bit enabled Intel Xeons.
175
176	  To compile this driver as a module, choose M here: the
177	  module will be called speedstep-centrino.
178
179	  For details, take a look at <file:Documentation/cpu-freq/>.
180
181	  If in doubt, say N.
182
183config X86_SPEEDSTEP_CENTRINO_TABLE
184	bool "Built-in tables for Banias CPUs"
185	depends on X86_32 && X86_SPEEDSTEP_CENTRINO
186	default y
187	help
188	  Use built-in tables for Banias CPUs if ACPI encoding
189	  is not available.
190
191	  If in doubt, say N.
192
193config X86_SPEEDSTEP_ICH
194	tristate "Intel Speedstep on ICH-M chipsets (ioport interface)"
195	depends on X86_32
196	help
197	  This adds the CPUFreq driver for certain mobile Intel Pentium III
198	  (Coppermine), all mobile Intel Pentium III-M (Tualatin) and all
199	  mobile Intel Pentium 4 P4-M on systems which have an Intel ICH2,
200	  ICH3 or ICH4 southbridge.
201
202	  For details, take a look at <file:Documentation/cpu-freq/>.
203
204	  If in doubt, say N.
205
206config X86_SPEEDSTEP_SMI
207	tristate "Intel SpeedStep on 440BX/ZX/MX chipsets (SMI interface)"
208	depends on X86_32
209	help
210	  This adds the CPUFreq driver for certain mobile Intel Pentium III
211	  (Coppermine), all mobile Intel Pentium III-M (Tualatin)
212	  on systems which have an Intel 440BX/ZX/MX southbridge.
213
214	  For details, take a look at <file:Documentation/cpu-freq/>.
215
216	  If in doubt, say N.
217
218config X86_P4_CLOCKMOD
219	tristate "Intel Pentium 4 clock modulation"
220	help
221	  This adds the CPUFreq driver for Intel Pentium 4 / XEON
222	  processors.  When enabled it will lower CPU temperature by skipping
223	  clocks.
224
225	  This driver should be only used in exceptional
226	  circumstances when very low power is needed because it causes severe
227	  slowdowns and noticeable latencies.  Normally Speedstep should be used
228	  instead.
229
230	  To compile this driver as a module, choose M here: the
231	  module will be called p4-clockmod.
232
233	  For details, take a look at <file:Documentation/cpu-freq/>.
234
235	  Unless you are absolutely sure say N.
236
237config X86_CPUFREQ_NFORCE2
238	tristate "nVidia nForce2 FSB changing"
239	depends on X86_32
240	help
241	  This adds the CPUFreq driver for FSB changing on nVidia nForce2
242	  platforms.
243
244	  For details, take a look at <file:Documentation/cpu-freq/>.
245
246	  If in doubt, say N.
247
248config X86_LONGRUN
249	tristate "Transmeta LongRun"
250	depends on X86_32
251	help
252	  This adds the CPUFreq driver for Transmeta Crusoe and Efficeon processors
253	  which support LongRun.
254
255	  For details, take a look at <file:Documentation/cpu-freq/>.
256
257	  If in doubt, say N.
258
259config X86_LONGHAUL
260	tristate "VIA Cyrix III Longhaul"
261	depends on X86_32 && ACPI_PROCESSOR
262	help
263	  This adds the CPUFreq driver for VIA Samuel/CyrixIII,
264	  VIA Cyrix Samuel/C3, VIA Cyrix Ezra and VIA Cyrix Ezra-T
265	  processors.
266
267	  For details, take a look at <file:Documentation/cpu-freq/>.
268
269	  If in doubt, say N.
270
271config X86_E_POWERSAVER
272	tristate "VIA C7 Enhanced PowerSaver (DANGEROUS)"
273	depends on X86_32 && ACPI_PROCESSOR
274	help
275	  This adds the CPUFreq driver for VIA C7 processors.  However, this driver
276	  does not have any safeguards to prevent operating the CPU out of spec
277	  and is thus considered dangerous.  Please use the regular ACPI cpufreq
278	  driver, enabled by CONFIG_X86_ACPI_CPUFREQ.
279
280	  If in doubt, say N.
281
282comment "shared options"
283
284config X86_SPEEDSTEP_LIB
285	tristate
286	default (X86_SPEEDSTEP_ICH || X86_SPEEDSTEP_SMI || X86_P4_CLOCKMOD)
287
288config X86_SPEEDSTEP_RELAXED_CAP_CHECK
289	bool "Relaxed speedstep capability checks"
290	depends on X86_32 && (X86_SPEEDSTEP_SMI || X86_SPEEDSTEP_ICH)
291	help
292	  Don't perform all checks for a speedstep capable system which would
293	  normally be done. Some ancient or strange systems, though speedstep
294	  capable, don't always indicate that they are speedstep capable. This
295	  option lets the probing code bypass some of those checks if the
296	  parameter "relaxed_check=1" is passed to the module.
297
298