xref: /openbmc/linux/drivers/cpufreq/Kconfig (revision 56d06fa2) 
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_COMMON
22	select IRQ_WORK
23	bool
24
25config CPU_FREQ_BOOST_SW
26	bool
27	depends on THERMAL
28
29config CPU_FREQ_STAT
30	tristate "CPU frequency translation statistics"
31	default y
32	help
33	  This driver exports CPU frequency statistics information through sysfs
34	  file system.
35
36	  To compile this driver as a module, choose M here: the
37	  module will be called cpufreq_stats.
38
39	  If in doubt, say N.
40
41config CPU_FREQ_STAT_DETAILS
42	bool "CPU frequency translation statistics details"
43	depends on CPU_FREQ_STAT
44	help
45	  This will show detail CPU frequency translation table in sysfs file
46	  system.
47
48	  If in doubt, say N.
49
50choice
51	prompt "Default CPUFreq governor"
52	default CPU_FREQ_DEFAULT_GOV_USERSPACE if ARM_SA1100_CPUFREQ || ARM_SA1110_CPUFREQ
53	default CPU_FREQ_DEFAULT_GOV_PERFORMANCE
54	help
55	  This option sets which CPUFreq governor shall be loaded at
56	  startup. If in doubt, select 'performance'.
57
58config CPU_FREQ_DEFAULT_GOV_PERFORMANCE
59	bool "performance"
60	select CPU_FREQ_GOV_PERFORMANCE
61	help
62	  Use the CPUFreq governor 'performance' as default. This sets
63	  the frequency statically to the highest frequency supported by
64	  the CPU.
65
66config CPU_FREQ_DEFAULT_GOV_POWERSAVE
67	bool "powersave"
68	select CPU_FREQ_GOV_POWERSAVE
69	help
70	  Use the CPUFreq governor 'powersave' as default. This sets
71	  the frequency statically to the lowest frequency supported by
72	  the CPU.
73
74config CPU_FREQ_DEFAULT_GOV_USERSPACE
75	bool "userspace"
76	select CPU_FREQ_GOV_USERSPACE
77	help
78	  Use the CPUFreq governor 'userspace' as default. This allows
79	  you to set the CPU frequency manually or when a userspace
80	  program shall be able to set the CPU dynamically without having
81	  to enable the userspace governor manually.
82
83config CPU_FREQ_DEFAULT_GOV_ONDEMAND
84	bool "ondemand"
85	select CPU_FREQ_GOV_ONDEMAND
86	select CPU_FREQ_GOV_PERFORMANCE
87	help
88	  Use the CPUFreq governor 'ondemand' as default. This allows
89	  you to get a full dynamic frequency capable system by simply
90	  loading your cpufreq low-level hardware driver.
91	  Be aware that not all cpufreq drivers support the ondemand
92	  governor. If unsure have a look at the help section of the
93	  driver. Fallback governor will be the performance governor.
94
95config CPU_FREQ_DEFAULT_GOV_CONSERVATIVE
96	bool "conservative"
97	select CPU_FREQ_GOV_CONSERVATIVE
98	select CPU_FREQ_GOV_PERFORMANCE
99	help
100	  Use the CPUFreq governor 'conservative' as default. This allows
101	  you to get a full dynamic frequency capable system by simply
102	  loading your cpufreq low-level hardware driver.
103	  Be aware that not all cpufreq drivers support the conservative
104	  governor. If unsure have a look at the help section of the
105	  driver. Fallback governor will be the performance governor.
106endchoice
107
108config CPU_FREQ_GOV_PERFORMANCE
109	tristate "'performance' governor"
110	help
111	  This cpufreq governor sets the frequency statically to the
112	  highest available CPU frequency.
113
114	  To compile this driver as a module, choose M here: the
115	  module will be called cpufreq_performance.
116
117	  If in doubt, say Y.
118
119config CPU_FREQ_GOV_POWERSAVE
120	tristate "'powersave' governor"
121	help
122	  This cpufreq governor sets the frequency statically to the
123	  lowest available CPU frequency.
124
125	  To compile this driver as a module, choose M here: the
126	  module will be called cpufreq_powersave.
127
128	  If in doubt, say Y.
129
130config CPU_FREQ_GOV_USERSPACE
131	tristate "'userspace' governor for userspace frequency scaling"
132	help
133	  Enable this cpufreq governor when you either want to set the
134	  CPU frequency manually or when a userspace program shall
135	  be able to set the CPU dynamically, like on LART
136	  <http://www.lartmaker.nl/>.
137
138	  To compile this driver as a module, choose M here: the
139	  module will be called cpufreq_userspace.
140
141	  For details, take a look at <file:Documentation/cpu-freq/>.
142
143	  If in doubt, say Y.
144
145config CPU_FREQ_GOV_ONDEMAND
146	tristate "'ondemand' cpufreq policy governor"
147	select CPU_FREQ_GOV_COMMON
148	help
149	  'ondemand' - This driver adds a dynamic cpufreq policy governor.
150	  The governor does a periodic polling and
151	  changes frequency based on the CPU utilization.
152	  The support for this governor depends on CPU capability to
153	  do fast frequency switching (i.e, very low latency frequency
154	  transitions).
155
156	  To compile this driver as a module, choose M here: the
157	  module will be called cpufreq_ondemand.
158
159	  For details, take a look at linux/Documentation/cpu-freq.
160
161	  If in doubt, say N.
162
163config CPU_FREQ_GOV_CONSERVATIVE
164	tristate "'conservative' cpufreq governor"
165	depends on CPU_FREQ
166	select CPU_FREQ_GOV_COMMON
167	help
168	  'conservative' - this driver is rather similar to the 'ondemand'
169	  governor both in its source code and its purpose, the difference is
170	  its optimisation for better suitability in a battery powered
171	  environment.  The frequency is gracefully increased and decreased
172	  rather than jumping to 100% when speed is required.
173
174	  If you have a desktop machine then you should really be considering
175	  the 'ondemand' governor instead, however if you are using a laptop,
176	  PDA or even an AMD64 based computer (due to the unacceptable
177	  step-by-step latency issues between the minimum and maximum frequency
178	  transitions in the CPU) you will probably want to use this governor.
179
180	  To compile this driver as a module, choose M here: the
181	  module will be called cpufreq_conservative.
182
183	  For details, take a look at linux/Documentation/cpu-freq.
184
185	  If in doubt, say N.
186
187comment "CPU frequency scaling drivers"
188
189config CPUFREQ_DT
190	tristate "Generic DT based cpufreq driver"
191	depends on HAVE_CLK && OF
192	# if CPU_THERMAL is on and THERMAL=m, CPUFREQ_DT cannot be =y:
193	depends on !CPU_THERMAL || THERMAL
194	select PM_OPP
195	help
196	  This adds a generic DT based cpufreq driver for frequency management.
197	  It supports both uniprocessor (UP) and symmetric multiprocessor (SMP)
198	  systems which share clock and voltage across all CPUs.
199
200	  If in doubt, say N.
201
202if X86
203source "drivers/cpufreq/Kconfig.x86"
204endif
205
206if ARM || ARM64
207source "drivers/cpufreq/Kconfig.arm"
208endif
209
210if PPC32 || PPC64
211source "drivers/cpufreq/Kconfig.powerpc"
212endif
213
214if AVR32
215config AVR32_AT32AP_CPUFREQ
216	bool "CPU frequency driver for AT32AP"
217	depends on PLATFORM_AT32AP
218	default n
219	help
220	  This enables the CPU frequency driver for AT32AP processors.
221	  If in doubt, say N.
222endif
223
224if IA64
225config IA64_ACPI_CPUFREQ
226	tristate "ACPI Processor P-States driver"
227	depends on ACPI_PROCESSOR
228	help
229	This driver adds a CPUFreq driver which utilizes the ACPI
230	Processor Performance States.
231
232	For details, take a look at <file:Documentation/cpu-freq/>.
233
234	If in doubt, say N.
235endif
236
237if MIPS
238config LOONGSON2_CPUFREQ
239	tristate "Loongson2 CPUFreq Driver"
240	help
241	  This option adds a CPUFreq driver for loongson processors which
242	  support software configurable cpu frequency.
243
244	  Loongson2F and it's successors support this feature.
245
246	  For details, take a look at <file:Documentation/cpu-freq/>.
247
248	  If in doubt, say N.
249
250config LOONGSON1_CPUFREQ
251	tristate "Loongson1 CPUFreq Driver"
252	help
253	  This option adds a CPUFreq driver for loongson1 processors which
254	  support software configurable cpu frequency.
255
256	  For details, take a look at <file:Documentation/cpu-freq/>.
257
258	  If in doubt, say N.
259endif
260
261if SPARC64
262config SPARC_US3_CPUFREQ
263	tristate "UltraSPARC-III CPU Frequency driver"
264	help
265	  This adds the CPUFreq driver for UltraSPARC-III processors.
266
267	  For details, take a look at <file:Documentation/cpu-freq>.
268
269	  If in doubt, say N.
270
271config SPARC_US2E_CPUFREQ
272	tristate "UltraSPARC-IIe CPU Frequency driver"
273	help
274	  This adds the CPUFreq driver for UltraSPARC-IIe processors.
275
276	  For details, take a look at <file:Documentation/cpu-freq>.
277
278	  If in doubt, say N.
279endif
280
281if SUPERH
282config SH_CPU_FREQ
283	tristate "SuperH CPU Frequency driver"
284	help
285	  This adds the cpufreq driver for SuperH. Any CPU that supports
286	  clock rate rounding through the clock framework can use this
287	  driver. While it will make the kernel slightly larger, this is
288	  harmless for CPUs that don't support rate rounding. The driver
289	  will also generate a notice in the boot log before disabling
290	  itself if the CPU in question is not capable of rate rounding.
291
292	  For details, take a look at <file:Documentation/cpu-freq>.
293
294	  If unsure, say N.
295endif
296
297config QORIQ_CPUFREQ
298	tristate "CPU frequency scaling driver for Freescale QorIQ SoCs"
299	depends on OF && COMMON_CLK && (PPC_E500MC || ARM)
300	depends on !CPU_THERMAL || THERMAL
301	select CLK_QORIQ
302	help
303	  This adds the CPUFreq driver support for Freescale QorIQ SoCs
304	  which are capable of changing the CPU's frequency dynamically.
305
306endif
307endmenu
308