xref: /openbmc/linux/drivers/cpufreq/Kconfig (revision 77d84ff8) 
1menu "CPU Frequency scaling"
2
3config CPU_FREQ
4	bool "CPU Frequency scaling"
5	help
6	  CPU Frequency scaling allows you to change the clock speed of
7	  CPUs on the fly. This is a nice method to save power, because
8	  the lower the CPU clock speed, the less power the CPU consumes.
9
10	  Note that this driver doesn't automatically change the CPU
11	  clock speed, you need to either enable a dynamic cpufreq governor
12	  (see below) after boot, or use a userspace tool.
13
14	  For details, take a look at <file:Documentation/cpu-freq>.
15
16	  If in doubt, say N.
17
18if CPU_FREQ
19
20config CPU_FREQ_GOV_COMMON
21	bool
22
23config CPU_FREQ_STAT
24	tristate "CPU frequency translation statistics"
25	default y
26	help
27	  This driver exports CPU frequency statistics information through sysfs
28	  file system.
29
30	  To compile this driver as a module, choose M here: the
31	  module will be called cpufreq_stats.
32
33	  If in doubt, say N.
34
35config CPU_FREQ_STAT_DETAILS
36	bool "CPU frequency translation statistics details"
37	depends on CPU_FREQ_STAT
38	help
39	  This will show detail CPU frequency translation table in sysfs file
40	  system.
41
42	  If in doubt, say N.
43
44choice
45	prompt "Default CPUFreq governor"
46	default CPU_FREQ_DEFAULT_GOV_USERSPACE if ARM_SA1100_CPUFREQ || ARM_SA1110_CPUFREQ
47	default CPU_FREQ_DEFAULT_GOV_PERFORMANCE
48	help
49	  This option sets which CPUFreq governor shall be loaded at
50	  startup. If in doubt, select 'performance'.
51
52config CPU_FREQ_DEFAULT_GOV_PERFORMANCE
53	bool "performance"
54	select CPU_FREQ_GOV_PERFORMANCE
55	help
56	  Use the CPUFreq governor 'performance' as default. This sets
57	  the frequency statically to the highest frequency supported by
58	  the CPU.
59
60config CPU_FREQ_DEFAULT_GOV_POWERSAVE
61	bool "powersave"
62	depends on EXPERT
63	select CPU_FREQ_GOV_POWERSAVE
64	help
65	  Use the CPUFreq governor 'powersave' as default. This sets
66	  the frequency statically to the lowest frequency supported by
67	  the CPU.
68
69config CPU_FREQ_DEFAULT_GOV_USERSPACE
70	bool "userspace"
71	select CPU_FREQ_GOV_USERSPACE
72	help
73	  Use the CPUFreq governor 'userspace' as default. This allows
74	  you to set the CPU frequency manually or when a userspace
75	  program shall be able to set the CPU dynamically without having
76	  to enable the userspace governor manually.
77
78config CPU_FREQ_DEFAULT_GOV_ONDEMAND
79	bool "ondemand"
80	select CPU_FREQ_GOV_ONDEMAND
81	select CPU_FREQ_GOV_PERFORMANCE
82	help
83	  Use the CPUFreq governor 'ondemand' as default. This allows
84	  you to get a full dynamic frequency capable system by simply
85	  loading your cpufreq low-level hardware driver.
86	  Be aware that not all cpufreq drivers support the ondemand
87	  governor. If unsure have a look at the help section of the
88	  driver. Fallback governor will be the performance governor.
89
90config CPU_FREQ_DEFAULT_GOV_CONSERVATIVE
91	bool "conservative"
92	select CPU_FREQ_GOV_CONSERVATIVE
93	select CPU_FREQ_GOV_PERFORMANCE
94	help
95	  Use the CPUFreq governor 'conservative' as default. This allows
96	  you to get a full dynamic frequency capable system by simply
97	  loading your cpufreq low-level hardware driver.
98	  Be aware that not all cpufreq drivers support the conservative
99	  governor. If unsure have a look at the help section of the
100	  driver. Fallback governor will be the performance governor.
101endchoice
102
103config CPU_FREQ_GOV_PERFORMANCE
104	tristate "'performance' governor"
105	help
106	  This cpufreq governor sets the frequency statically to the
107	  highest available CPU frequency.
108
109	  To compile this driver as a module, choose M here: the
110	  module will be called cpufreq_performance.
111
112	  If in doubt, say Y.
113
114config CPU_FREQ_GOV_POWERSAVE
115	tristate "'powersave' governor"
116	help
117	  This cpufreq governor sets the frequency statically to the
118	  lowest available CPU frequency.
119
120	  To compile this driver as a module, choose M here: the
121	  module will be called cpufreq_powersave.
122
123	  If in doubt, say Y.
124
125config CPU_FREQ_GOV_USERSPACE
126	tristate "'userspace' governor for userspace frequency scaling"
127	help
128	  Enable this cpufreq governor when you either want to set the
129	  CPU frequency manually or when a userspace program shall
130	  be able to set the CPU dynamically, like on LART
131	  <http://www.lartmaker.nl/>.
132
133	  To compile this driver as a module, choose M here: the
134	  module will be called cpufreq_userspace.
135
136	  For details, take a look at <file:Documentation/cpu-freq/>.
137
138	  If in doubt, say Y.
139
140config CPU_FREQ_GOV_ONDEMAND
141	tristate "'ondemand' cpufreq policy governor"
142	select CPU_FREQ_GOV_COMMON
143	help
144	  'ondemand' - This driver adds a dynamic cpufreq policy governor.
145	  The governor does a periodic polling and
146	  changes frequency based on the CPU utilization.
147	  The support for this governor depends on CPU capability to
148	  do fast frequency switching (i.e, very low latency frequency
149	  transitions).
150
151	  To compile this driver as a module, choose M here: the
152	  module will be called cpufreq_ondemand.
153
154	  For details, take a look at linux/Documentation/cpu-freq.
155
156	  If in doubt, say N.
157
158config CPU_FREQ_GOV_CONSERVATIVE
159	tristate "'conservative' cpufreq governor"
160	depends on CPU_FREQ
161	select CPU_FREQ_GOV_COMMON
162	help
163	  'conservative' - this driver is rather similar to the 'ondemand'
164	  governor both in its source code and its purpose, the difference is
165	  its optimisation for better suitability in a battery powered
166	  environment.  The frequency is gracefully increased and decreased
167	  rather than jumping to 100% when speed is required.
168
169	  If you have a desktop machine then you should really be considering
170	  the 'ondemand' governor instead, however if you are using a laptop,
171	  PDA or even an AMD64 based computer (due to the unacceptable
172	  step-by-step latency issues between the minimum and maximum frequency
173	  transitions in the CPU) you will probably want to use this governor.
174
175	  To compile this driver as a module, choose M here: the
176	  module will be called cpufreq_conservative.
177
178	  For details, take a look at linux/Documentation/cpu-freq.
179
180	  If in doubt, say N.
181
182config GENERIC_CPUFREQ_CPU0
183	tristate "Generic CPU0 cpufreq driver"
184	depends on HAVE_CLK && REGULATOR && PM_OPP && OF
185	help
186	  This adds a generic cpufreq driver for CPU0 frequency management.
187	  It supports both uniprocessor (UP) and symmetric multiprocessor (SMP)
188	  systems which share clock and voltage across all CPUs.
189
190	  If in doubt, say N.
191
192menu "x86 CPU frequency scaling drivers"
193depends on X86
194source "drivers/cpufreq/Kconfig.x86"
195endmenu
196
197menu "ARM CPU frequency scaling drivers"
198depends on ARM
199source "drivers/cpufreq/Kconfig.arm"
200endmenu
201
202menu "AVR32 CPU frequency scaling drivers"
203depends on AVR32
204
205config AVR32_AT32AP_CPUFREQ
206	bool "CPU frequency driver for AT32AP"
207	depends on PLATFORM_AT32AP
208	default n
209	help
210	  This enables the CPU frequency driver for AT32AP processors.
211	  If in doubt, say N.
212
213endmenu
214
215menu "CPUFreq processor drivers"
216depends on IA64
217
218config IA64_ACPI_CPUFREQ
219	tristate "ACPI Processor P-States driver"
220	depends on ACPI_PROCESSOR
221	help
222	This driver adds a CPUFreq driver which utilizes the ACPI
223	Processor Performance States.
224
225	For details, take a look at <file:Documentation/cpu-freq/>.
226
227	If in doubt, say N.
228
229endmenu
230
231menu "MIPS CPUFreq processor drivers"
232depends on MIPS
233
234config LOONGSON2_CPUFREQ
235	tristate "Loongson2 CPUFreq Driver"
236	help
237	  This option adds a CPUFreq driver for loongson processors which
238	  support software configurable cpu frequency.
239
240	  Loongson2F and it's successors support this feature.
241
242	  For details, take a look at <file:Documentation/cpu-freq/>.
243
244	  If in doubt, say N.
245
246endmenu
247
248menu "PowerPC CPU frequency scaling drivers"
249depends on PPC32 || PPC64
250source "drivers/cpufreq/Kconfig.powerpc"
251endmenu
252
253menu "SPARC CPU frequency scaling drivers"
254depends on SPARC64
255config SPARC_US3_CPUFREQ
256	tristate "UltraSPARC-III CPU Frequency driver"
257	help
258	  This adds the CPUFreq driver for UltraSPARC-III processors.
259
260	  For details, take a look at <file:Documentation/cpu-freq>.
261
262	  If in doubt, say N.
263
264config SPARC_US2E_CPUFREQ
265	tristate "UltraSPARC-IIe CPU Frequency driver"
266	help
267	  This adds the CPUFreq driver for UltraSPARC-IIe processors.
268
269	  For details, take a look at <file:Documentation/cpu-freq>.
270
271	  If in doubt, say N.
272endmenu
273
274menu "SH CPU Frequency scaling"
275depends on SUPERH
276config SH_CPU_FREQ
277	tristate "SuperH CPU Frequency driver"
278	help
279	  This adds the cpufreq driver for SuperH. Any CPU that supports
280	  clock rate rounding through the clock framework can use this
281	  driver. While it will make the kernel slightly larger, this is
282	  harmless for CPUs that don't support rate rounding. The driver
283	  will also generate a notice in the boot log before disabling
284	  itself if the CPU in question is not capable of rate rounding.
285
286	  For details, take a look at <file:Documentation/cpu-freq>.
287
288	  If unsure, say N.
289endmenu
290
291endif
292endmenu
293