xref: /openbmc/linux/drivers/cpufreq/Kconfig (revision a701d28e) 
1# SPDX-License-Identifier: GPL-2.0-only
2menu "CPU Frequency scaling"
3
4config CPU_FREQ
5	bool "CPU Frequency scaling"
6	select SRCU
7	help
8	  CPU Frequency scaling allows you to change the clock speed of
9	  CPUs on the fly. This is a nice method to save power, because
10	  the lower the CPU clock speed, the less power the CPU consumes.
11
12	  Note that this driver doesn't automatically change the CPU
13	  clock speed, you need to either enable a dynamic cpufreq governor
14	  (see below) after boot, or use a userspace tool.
15
16	  For details, take a look at <file:Documentation/cpu-freq>.
17
18	  If in doubt, say N.
19
20if CPU_FREQ
21
22config CPU_FREQ_GOV_ATTR_SET
23	bool
24
25config CPU_FREQ_GOV_COMMON
26	select CPU_FREQ_GOV_ATTR_SET
27	select IRQ_WORK
28	bool
29
30config CPU_FREQ_STAT
31	bool "CPU frequency transition statistics"
32	help
33	  Export CPU frequency statistics information through sysfs.
34
35	  If in doubt, say N.
36
37choice
38	prompt "Default CPUFreq governor"
39	default CPU_FREQ_DEFAULT_GOV_USERSPACE if ARM_SA1100_CPUFREQ || ARM_SA1110_CPUFREQ
40	default CPU_FREQ_DEFAULT_GOV_SCHEDUTIL if ARM64 || ARM
41	default CPU_FREQ_DEFAULT_GOV_SCHEDUTIL if X86_INTEL_PSTATE && SMP
42	default CPU_FREQ_DEFAULT_GOV_PERFORMANCE
43	help
44	  This option sets which CPUFreq governor shall be loaded at
45	  startup. If in doubt, use the default setting.
46
47config CPU_FREQ_DEFAULT_GOV_PERFORMANCE
48	bool "performance"
49	select CPU_FREQ_GOV_PERFORMANCE
50	help
51	  Use the CPUFreq governor 'performance' as default. This sets
52	  the frequency statically to the highest frequency supported by
53	  the CPU.
54
55config CPU_FREQ_DEFAULT_GOV_POWERSAVE
56	bool "powersave"
57	select CPU_FREQ_GOV_POWERSAVE
58	help
59	  Use the CPUFreq governor 'powersave' as default. This sets
60	  the frequency statically to the lowest frequency supported by
61	  the CPU.
62
63config CPU_FREQ_DEFAULT_GOV_USERSPACE
64	bool "userspace"
65	select CPU_FREQ_GOV_USERSPACE
66	help
67	  Use the CPUFreq governor 'userspace' as default. This allows
68	  you to set the CPU frequency manually or when a userspace
69	  program shall be able to set the CPU dynamically without having
70	  to enable the userspace governor manually.
71
72config CPU_FREQ_DEFAULT_GOV_ONDEMAND
73	bool "ondemand"
74	depends on !(X86_INTEL_PSTATE && SMP)
75	select CPU_FREQ_GOV_ONDEMAND
76	select CPU_FREQ_GOV_PERFORMANCE
77	help
78	  Use the CPUFreq governor 'ondemand' as default. This allows
79	  you to get a full dynamic frequency capable system by simply
80	  loading your cpufreq low-level hardware driver.
81	  Be aware that not all cpufreq drivers support the ondemand
82	  governor. If unsure have a look at the help section of the
83	  driver. Fallback governor will be the performance governor.
84
85config CPU_FREQ_DEFAULT_GOV_CONSERVATIVE
86	bool "conservative"
87	depends on !(X86_INTEL_PSTATE && SMP)
88	select CPU_FREQ_GOV_CONSERVATIVE
89	select CPU_FREQ_GOV_PERFORMANCE
90	help
91	  Use the CPUFreq governor 'conservative' as default. This allows
92	  you to get a full dynamic frequency capable system by simply
93	  loading your cpufreq low-level hardware driver.
94	  Be aware that not all cpufreq drivers support the conservative
95	  governor. If unsure have a look at the help section of the
96	  driver. Fallback governor will be the performance governor.
97
98config CPU_FREQ_DEFAULT_GOV_SCHEDUTIL
99	bool "schedutil"
100	depends on SMP
101	select CPU_FREQ_GOV_SCHEDUTIL
102	select CPU_FREQ_GOV_PERFORMANCE
103	help
104	  Use the 'schedutil' CPUFreq governor by default. If unsure,
105	  have a look at the help section of that governor. The fallback
106	  governor will be 'performance'.
107
108endchoice
109
110config CPU_FREQ_GOV_PERFORMANCE
111	tristate "'performance' governor"
112	help
113	  This cpufreq governor sets the frequency statically to the
114	  highest available CPU frequency.
115
116	  To compile this driver as a module, choose M here: the
117	  module will be called cpufreq_performance.
118
119	  If in doubt, say Y.
120
121config CPU_FREQ_GOV_POWERSAVE
122	tristate "'powersave' governor"
123	help
124	  This cpufreq governor sets the frequency statically to the
125	  lowest available CPU frequency.
126
127	  To compile this driver as a module, choose M here: the
128	  module will be called cpufreq_powersave.
129
130	  If in doubt, say Y.
131
132config CPU_FREQ_GOV_USERSPACE
133	tristate "'userspace' governor for userspace frequency scaling"
134	help
135	  Enable this cpufreq governor when you either want to set the
136	  CPU frequency manually or when a userspace program shall
137	  be able to set the CPU dynamically, like on LART
138	  <http://www.lartmaker.nl/>.
139
140	  To compile this driver as a module, choose M here: the
141	  module will be called cpufreq_userspace.
142
143	  For details, take a look at <file:Documentation/cpu-freq/>.
144
145	  If in doubt, say Y.
146
147config CPU_FREQ_GOV_ONDEMAND
148	tristate "'ondemand' cpufreq policy governor"
149	select CPU_FREQ_GOV_COMMON
150	help
151	  'ondemand' - This driver adds a dynamic cpufreq policy governor.
152	  The governor does a periodic polling and
153	  changes frequency based on the CPU utilization.
154	  The support for this governor depends on CPU capability to
155	  do fast frequency switching (i.e, very low latency frequency
156	  transitions).
157
158	  To compile this driver as a module, choose M here: the
159	  module will be called cpufreq_ondemand.
160
161	  For details, take a look at linux/Documentation/cpu-freq.
162
163	  If in doubt, say N.
164
165config CPU_FREQ_GOV_CONSERVATIVE
166	tristate "'conservative' cpufreq governor"
167	depends on CPU_FREQ
168	select CPU_FREQ_GOV_COMMON
169	help
170	  'conservative' - this driver is rather similar to the 'ondemand'
171	  governor both in its source code and its purpose, the difference is
172	  its optimisation for better suitability in a battery powered
173	  environment.  The frequency is gracefully increased and decreased
174	  rather than jumping to 100% when speed is required.
175
176	  If you have a desktop machine then you should really be considering
177	  the 'ondemand' governor instead, however if you are using a laptop,
178	  PDA or even an AMD64 based computer (due to the unacceptable
179	  step-by-step latency issues between the minimum and maximum frequency
180	  transitions in the CPU) you will probably want to use this governor.
181
182	  To compile this driver as a module, choose M here: the
183	  module will be called cpufreq_conservative.
184
185	  For details, take a look at linux/Documentation/cpu-freq.
186
187	  If in doubt, say N.
188
189config CPU_FREQ_GOV_SCHEDUTIL
190	bool "'schedutil' cpufreq policy governor"
191	depends on CPU_FREQ && SMP
192	select CPU_FREQ_GOV_ATTR_SET
193	select IRQ_WORK
194	help
195	  This governor makes decisions based on the utilization data provided
196	  by the scheduler.  It sets the CPU frequency to be proportional to
197	  the utilization/capacity ratio coming from the scheduler.  If the
198	  utilization is frequency-invariant, the new frequency is also
199	  proportional to the maximum available frequency.  If that is not the
200	  case, it is proportional to the current frequency of the CPU.  The
201	  frequency tipping point is at utilization/capacity equal to 80% in
202	  both cases.
203
204	  If in doubt, say N.
205
206comment "CPU frequency scaling drivers"
207
208config CPUFREQ_DT
209	tristate "Generic DT based cpufreq driver"
210	depends on HAVE_CLK && OF
211	select CPUFREQ_DT_PLATDEV
212	select PM_OPP
213	help
214	  This adds a generic DT based cpufreq driver for frequency management.
215	  It supports both uniprocessor (UP) and symmetric multiprocessor (SMP)
216	  systems.
217
218	  If in doubt, say N.
219
220config CPUFREQ_DT_PLATDEV
221	bool
222	help
223	  This adds a generic DT based cpufreq platdev driver for frequency
224	  management.  This creates a 'cpufreq-dt' platform device, on the
225	  supported platforms.
226
227	  If in doubt, say N.
228
229if X86
230source "drivers/cpufreq/Kconfig.x86"
231endif
232
233if ARM || ARM64
234source "drivers/cpufreq/Kconfig.arm"
235endif
236
237if PPC32 || PPC64
238source "drivers/cpufreq/Kconfig.powerpc"
239endif
240
241if IA64
242config IA64_ACPI_CPUFREQ
243	tristate "ACPI Processor P-States driver"
244	depends on ACPI_PROCESSOR
245	help
246	This driver adds a CPUFreq driver which utilizes the ACPI
247	Processor Performance States.
248
249	For details, take a look at <file:Documentation/cpu-freq/>.
250
251	If in doubt, say N.
252endif
253
254if MIPS
255config BMIPS_CPUFREQ
256	tristate "BMIPS CPUfreq Driver"
257	help
258	  This option adds a CPUfreq driver for BMIPS processors with
259	  support for configurable CPU frequency.
260
261	  For now, BMIPS5 chips are supported (such as the Broadcom 7425).
262
263	  If in doubt, say N.
264
265config LOONGSON2_CPUFREQ
266	tristate "Loongson2 CPUFreq Driver"
267	depends on LEMOTE_MACH2F
268	help
269	  This option adds a CPUFreq driver for loongson processors which
270	  support software configurable cpu frequency.
271
272	  Loongson2F and it's successors support this feature.
273
274	  For details, take a look at <file:Documentation/cpu-freq/>.
275
276	  If in doubt, say N.
277
278config LOONGSON1_CPUFREQ
279	tristate "Loongson1 CPUFreq Driver"
280	depends on LOONGSON1_LS1B
281	help
282	  This option adds a CPUFreq driver for loongson1 processors which
283	  support software configurable cpu frequency.
284
285	  For details, take a look at <file:Documentation/cpu-freq/>.
286
287	  If in doubt, say N.
288endif
289
290if SPARC64
291config SPARC_US3_CPUFREQ
292	tristate "UltraSPARC-III CPU Frequency driver"
293	help
294	  This adds the CPUFreq driver for UltraSPARC-III processors.
295
296	  For details, take a look at <file:Documentation/cpu-freq>.
297
298	  If in doubt, say N.
299
300config SPARC_US2E_CPUFREQ
301	tristate "UltraSPARC-IIe CPU Frequency driver"
302	help
303	  This adds the CPUFreq driver for UltraSPARC-IIe processors.
304
305	  For details, take a look at <file:Documentation/cpu-freq>.
306
307	  If in doubt, say N.
308endif
309
310if SUPERH
311config SH_CPU_FREQ
312	tristate "SuperH CPU Frequency driver"
313	help
314	  This adds the cpufreq driver for SuperH. Any CPU that supports
315	  clock rate rounding through the clock framework can use this
316	  driver. While it will make the kernel slightly larger, this is
317	  harmless for CPUs that don't support rate rounding. The driver
318	  will also generate a notice in the boot log before disabling
319	  itself if the CPU in question is not capable of rate rounding.
320
321	  For details, take a look at <file:Documentation/cpu-freq>.
322
323	  If unsure, say N.
324endif
325
326config QORIQ_CPUFREQ
327	tristate "CPU frequency scaling driver for Freescale QorIQ SoCs"
328	depends on OF && COMMON_CLK
329	depends on PPC_E500MC || SOC_LS1021A || ARCH_LAYERSCAPE || COMPILE_TEST
330	select CLK_QORIQ
331	help
332	  This adds the CPUFreq driver support for Freescale QorIQ SoCs
333	  which are capable of changing the CPU's frequency dynamically.
334
335endif
336endmenu
337