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