xref: /openbmc/linux/drivers/cpufreq/Kconfig (revision 1491eaf9) 
1menu "CPU Frequency scaling"
2
3config CPU_FREQ
4	bool "CPU Frequency scaling"
5	select SRCU
6	help
7	  CPU Frequency scaling allows you to change the clock speed of
8	  CPUs on the fly. This is a nice method to save power, because
9	  the lower the CPU clock speed, the less power the CPU consumes.
10
11	  Note that this driver doesn't automatically change the CPU
12	  clock speed, you need to either enable a dynamic cpufreq governor
13	  (see below) after boot, or use a userspace tool.
14
15	  For details, take a look at <file:Documentation/cpu-freq>.
16
17	  If in doubt, say N.
18
19if CPU_FREQ
20
21config CPU_FREQ_GOV_ATTR_SET
22	bool
23
24config CPU_FREQ_GOV_COMMON
25	select CPU_FREQ_GOV_ATTR_SET
26	select IRQ_WORK
27	bool
28
29config CPU_FREQ_BOOST_SW
30	bool
31	depends on THERMAL
32
33config CPU_FREQ_STAT
34	bool "CPU frequency transition statistics"
35	help
36	  Export CPU frequency statistics information through sysfs.
37
38	  If in doubt, say N.
39
40config CPU_FREQ_STAT_DETAILS
41	bool "CPU frequency transition statistics details"
42	depends on CPU_FREQ_STAT
43	help
44	  Show detailed CPU frequency transition table in sysfs.
45
46	  If in doubt, say N.
47
48choice
49	prompt "Default CPUFreq governor"
50	default CPU_FREQ_DEFAULT_GOV_USERSPACE if ARM_SA1100_CPUFREQ || ARM_SA1110_CPUFREQ
51	default CPU_FREQ_DEFAULT_GOV_PERFORMANCE
52	help
53	  This option sets which CPUFreq governor shall be loaded at
54	  startup. If in doubt, select 'performance'.
55
56config CPU_FREQ_DEFAULT_GOV_PERFORMANCE
57	bool "performance"
58	select CPU_FREQ_GOV_PERFORMANCE
59	help
60	  Use the CPUFreq governor 'performance' as default. This sets
61	  the frequency statically to the highest frequency supported by
62	  the CPU.
63
64config CPU_FREQ_DEFAULT_GOV_POWERSAVE
65	bool "powersave"
66	select CPU_FREQ_GOV_POWERSAVE
67	help
68	  Use the CPUFreq governor 'powersave' as default. This sets
69	  the frequency statically to the lowest frequency supported by
70	  the CPU.
71
72config CPU_FREQ_DEFAULT_GOV_USERSPACE
73	bool "userspace"
74	select CPU_FREQ_GOV_USERSPACE
75	help
76	  Use the CPUFreq governor 'userspace' as default. This allows
77	  you to set the CPU frequency manually or when a userspace
78	  program shall be able to set the CPU dynamically without having
79	  to enable the userspace governor manually.
80
81config CPU_FREQ_DEFAULT_GOV_ONDEMAND
82	bool "ondemand"
83	select CPU_FREQ_GOV_ONDEMAND
84	select CPU_FREQ_GOV_PERFORMANCE
85	help
86	  Use the CPUFreq governor 'ondemand' as default. This allows
87	  you to get a full dynamic frequency capable system by simply
88	  loading your cpufreq low-level hardware driver.
89	  Be aware that not all cpufreq drivers support the ondemand
90	  governor. If unsure have a look at the help section of the
91	  driver. Fallback governor will be the performance governor.
92
93config CPU_FREQ_DEFAULT_GOV_CONSERVATIVE
94	bool "conservative"
95	select CPU_FREQ_GOV_CONSERVATIVE
96	select CPU_FREQ_GOV_PERFORMANCE
97	help
98	  Use the CPUFreq governor 'conservative' as default. This allows
99	  you to get a full dynamic frequency capable system by simply
100	  loading your cpufreq low-level hardware driver.
101	  Be aware that not all cpufreq drivers support the conservative
102	  governor. If unsure have a look at the help section of the
103	  driver. Fallback governor will be the performance governor.
104
105config CPU_FREQ_DEFAULT_GOV_SCHEDUTIL
106	bool "schedutil"
107	depends on SMP
108	select CPU_FREQ_GOV_SCHEDUTIL
109	select CPU_FREQ_GOV_PERFORMANCE
110	help
111	  Use the 'schedutil' CPUFreq governor by default. If unsure,
112	  have a look at the help section of that governor. The fallback
113	  governor will be 'performance'.
114
115endchoice
116
117config CPU_FREQ_GOV_PERFORMANCE
118	tristate "'performance' governor"
119	help
120	  This cpufreq governor sets the frequency statically to the
121	  highest available CPU frequency.
122
123	  To compile this driver as a module, choose M here: the
124	  module will be called cpufreq_performance.
125
126	  If in doubt, say Y.
127
128config CPU_FREQ_GOV_POWERSAVE
129	tristate "'powersave' governor"
130	help
131	  This cpufreq governor sets the frequency statically to the
132	  lowest available CPU frequency.
133
134	  To compile this driver as a module, choose M here: the
135	  module will be called cpufreq_powersave.
136
137	  If in doubt, say Y.
138
139config CPU_FREQ_GOV_USERSPACE
140	tristate "'userspace' governor for userspace frequency scaling"
141	help
142	  Enable this cpufreq governor when you either want to set the
143	  CPU frequency manually or when a userspace program shall
144	  be able to set the CPU dynamically, like on LART
145	  <http://www.lartmaker.nl/>.
146
147	  To compile this driver as a module, choose M here: the
148	  module will be called cpufreq_userspace.
149
150	  For details, take a look at <file:Documentation/cpu-freq/>.
151
152	  If in doubt, say Y.
153
154config CPU_FREQ_GOV_ONDEMAND
155	tristate "'ondemand' cpufreq policy governor"
156	select CPU_FREQ_GOV_COMMON
157	help
158	  'ondemand' - This driver adds a dynamic cpufreq policy governor.
159	  The governor does a periodic polling and
160	  changes frequency based on the CPU utilization.
161	  The support for this governor depends on CPU capability to
162	  do fast frequency switching (i.e, very low latency frequency
163	  transitions).
164
165	  To compile this driver as a module, choose M here: the
166	  module will be called cpufreq_ondemand.
167
168	  For details, take a look at linux/Documentation/cpu-freq.
169
170	  If in doubt, say N.
171
172config CPU_FREQ_GOV_CONSERVATIVE
173	tristate "'conservative' cpufreq governor"
174	depends on CPU_FREQ
175	select CPU_FREQ_GOV_COMMON
176	help
177	  'conservative' - this driver is rather similar to the 'ondemand'
178	  governor both in its source code and its purpose, the difference is
179	  its optimisation for better suitability in a battery powered
180	  environment.  The frequency is gracefully increased and decreased
181	  rather than jumping to 100% when speed is required.
182
183	  If you have a desktop machine then you should really be considering
184	  the 'ondemand' governor instead, however if you are using a laptop,
185	  PDA or even an AMD64 based computer (due to the unacceptable
186	  step-by-step latency issues between the minimum and maximum frequency
187	  transitions in the CPU) you will probably want to use this governor.
188
189	  To compile this driver as a module, choose M here: the
190	  module will be called cpufreq_conservative.
191
192	  For details, take a look at linux/Documentation/cpu-freq.
193
194	  If in doubt, say N.
195
196config CPU_FREQ_GOV_SCHEDUTIL
197	tristate "'schedutil' cpufreq policy governor"
198	depends on CPU_FREQ && SMP
199	select CPU_FREQ_GOV_ATTR_SET
200	select IRQ_WORK
201	help
202	  This governor makes decisions based on the utilization data provided
203	  by the scheduler.  It sets the CPU frequency to be proportional to
204	  the utilization/capacity ratio coming from the scheduler.  If the
205	  utilization is frequency-invariant, the new frequency is also
206	  proportional to the maximum available frequency.  If that is not the
207	  case, it is proportional to the current frequency of the CPU.  The
208	  frequency tipping point is at utilization/capacity equal to 80% in
209	  both cases.
210
211	  To compile this driver as a module, choose M here: the module will
212	  be called cpufreq_schedutil.
213
214	  If in doubt, say N.
215
216comment "CPU frequency scaling drivers"
217
218config CPUFREQ_DT
219	tristate "Generic DT based cpufreq driver"
220	depends on HAVE_CLK && OF
221	# if CPU_THERMAL is on and THERMAL=m, CPUFREQ_DT cannot be =y:
222	depends on !CPU_THERMAL || THERMAL
223	select CPUFREQ_DT_PLATDEV
224	select PM_OPP
225	help
226	  This adds a generic DT based cpufreq driver for frequency management.
227	  It supports both uniprocessor (UP) and symmetric multiprocessor (SMP)
228	  systems which share clock and voltage across all CPUs.
229
230	  If in doubt, say N.
231
232config CPUFREQ_DT_PLATDEV
233	bool
234	help
235	  This adds a generic DT based cpufreq platdev driver for frequency
236	  management.  This creates a 'cpufreq-dt' platform device, on the
237	  supported platforms.
238
239	  If in doubt, say N.
240
241if X86
242source "drivers/cpufreq/Kconfig.x86"
243endif
244
245if ARM || ARM64
246source "drivers/cpufreq/Kconfig.arm"
247endif
248
249if PPC32 || PPC64
250source "drivers/cpufreq/Kconfig.powerpc"
251endif
252
253if AVR32
254config AVR32_AT32AP_CPUFREQ
255	bool "CPU frequency driver for AT32AP"
256	depends on PLATFORM_AT32AP
257	default n
258	help
259	  This enables the CPU frequency driver for AT32AP processors.
260	  If in doubt, say N.
261endif
262
263if IA64
264config IA64_ACPI_CPUFREQ
265	tristate "ACPI Processor P-States driver"
266	depends on ACPI_PROCESSOR
267	help
268	This driver adds a CPUFreq driver which utilizes the ACPI
269	Processor Performance States.
270
271	For details, take a look at <file:Documentation/cpu-freq/>.
272
273	If in doubt, say N.
274endif
275
276if MIPS
277config LOONGSON2_CPUFREQ
278	tristate "Loongson2 CPUFreq Driver"
279	help
280	  This option adds a CPUFreq driver for loongson processors which
281	  support software configurable cpu frequency.
282
283	  Loongson2F and it's successors support this feature.
284
285	  For details, take a look at <file:Documentation/cpu-freq/>.
286
287	  If in doubt, say N.
288
289config LOONGSON1_CPUFREQ
290	tristate "Loongson1 CPUFreq Driver"
291	help
292	  This option adds a CPUFreq driver for loongson1 processors which
293	  support software configurable cpu frequency.
294
295	  For details, take a look at <file:Documentation/cpu-freq/>.
296
297	  If in doubt, say N.
298endif
299
300if SPARC64
301config SPARC_US3_CPUFREQ
302	tristate "UltraSPARC-III CPU Frequency driver"
303	help
304	  This adds the CPUFreq driver for UltraSPARC-III processors.
305
306	  For details, take a look at <file:Documentation/cpu-freq>.
307
308	  If in doubt, say N.
309
310config SPARC_US2E_CPUFREQ
311	tristate "UltraSPARC-IIe CPU Frequency driver"
312	help
313	  This adds the CPUFreq driver for UltraSPARC-IIe processors.
314
315	  For details, take a look at <file:Documentation/cpu-freq>.
316
317	  If in doubt, say N.
318endif
319
320if SUPERH
321config SH_CPU_FREQ
322	tristate "SuperH CPU Frequency driver"
323	help
324	  This adds the cpufreq driver for SuperH. Any CPU that supports
325	  clock rate rounding through the clock framework can use this
326	  driver. While it will make the kernel slightly larger, this is
327	  harmless for CPUs that don't support rate rounding. The driver
328	  will also generate a notice in the boot log before disabling
329	  itself if the CPU in question is not capable of rate rounding.
330
331	  For details, take a look at <file:Documentation/cpu-freq>.
332
333	  If unsure, say N.
334endif
335
336config QORIQ_CPUFREQ
337	tristate "CPU frequency scaling driver for Freescale QorIQ SoCs"
338	depends on OF && COMMON_CLK && (PPC_E500MC || ARM)
339	depends on !CPU_THERMAL || THERMAL
340	select CLK_QORIQ
341	help
342	  This adds the CPUFreq driver support for Freescale QorIQ SoCs
343	  which are capable of changing the CPU's frequency dynamically.
344
345endif
346endmenu
347