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bb0a56ec DJ |
1 | menu "CPU Frequency scaling" |
2 | ||
1da177e4 LT |
3 | config 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 | ||
18 | if CPU_FREQ | |
19 | ||
20 | config CPU_FREQ_TABLE | |
9101be53 | 21 | tristate |
1da177e4 | 22 | |
1e15f295 LF |
23 | config CPU_FREQ_GOV_COMMON |
24 | bool | |
25 | ||
1da177e4 | 26 | config CPU_FREQ_STAT |
9101be53 MF |
27 | tristate "CPU frequency translation statistics" |
28 | select CPU_FREQ_TABLE | |
29 | default y | |
30 | help | |
31 | This driver exports CPU frequency statistics information through sysfs | |
32 | file system. | |
33 | ||
34 | To compile this driver as a module, choose M here: the | |
35 | module will be called cpufreq_stats. | |
36 | ||
37 | If in doubt, say N. | |
1da177e4 LT |
38 | |
39 | config CPU_FREQ_STAT_DETAILS | |
9101be53 MF |
40 | bool "CPU frequency translation statistics details" |
41 | depends on CPU_FREQ_STAT | |
42 | help | |
43 | This will show detail CPU frequency translation table in sysfs file | |
44 | system. | |
45 | ||
46 | If in doubt, say N. | |
1da177e4 LT |
47 | |
48 | choice | |
49 | prompt "Default CPUFreq governor" | |
50 | default CPU_FREQ_DEFAULT_GOV_USERSPACE if CPU_FREQ_SA1100 || CPU_FREQ_SA1110 | |
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 | ||
56 | config 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 | ||
30d221db AG |
64 | config CPU_FREQ_DEFAULT_GOV_POWERSAVE |
65 | bool "powersave" | |
6a108a14 | 66 | depends on EXPERT |
30d221db AG |
67 | select CPU_FREQ_GOV_POWERSAVE |
68 | help | |
69 | Use the CPUFreq governor 'powersave' as default. This sets | |
70 | the frequency statically to the lowest frequency supported by | |
71 | the CPU. | |
72 | ||
1da177e4 LT |
73 | config CPU_FREQ_DEFAULT_GOV_USERSPACE |
74 | bool "userspace" | |
75 | select CPU_FREQ_GOV_USERSPACE | |
76 | help | |
77 | Use the CPUFreq governor 'userspace' as default. This allows | |
0211a9c8 | 78 | you to set the CPU frequency manually or when a userspace |
1da177e4 LT |
79 | program shall be able to set the CPU dynamically without having |
80 | to enable the userspace governor manually. | |
81 | ||
1c256245 TR |
82 | config CPU_FREQ_DEFAULT_GOV_ONDEMAND |
83 | bool "ondemand" | |
84 | select CPU_FREQ_GOV_ONDEMAND | |
85 | select CPU_FREQ_GOV_PERFORMANCE | |
86 | help | |
87 | Use the CPUFreq governor 'ondemand' 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 ondemand | |
91 | governor. If unsure have a look at the help section of the | |
92 | driver. Fallback governor will be the performance governor. | |
93 | ||
94 | config CPU_FREQ_DEFAULT_GOV_CONSERVATIVE | |
95 | bool "conservative" | |
96 | select CPU_FREQ_GOV_CONSERVATIVE | |
97 | select CPU_FREQ_GOV_PERFORMANCE | |
98 | help | |
99 | Use the CPUFreq governor 'conservative' as default. This allows | |
100 | you to get a full dynamic frequency capable system by simply | |
101 | loading your cpufreq low-level hardware driver. | |
102 | Be aware that not all cpufreq drivers support the conservative | |
103 | governor. If unsure have a look at the help section of the | |
104 | driver. Fallback governor will be the performance governor. | |
1da177e4 LT |
105 | endchoice |
106 | ||
107 | config CPU_FREQ_GOV_PERFORMANCE | |
9101be53 MF |
108 | tristate "'performance' governor" |
109 | help | |
1da177e4 LT |
110 | This cpufreq governor sets the frequency statically to the |
111 | highest available CPU frequency. | |
112 | ||
9101be53 MF |
113 | To compile this driver as a module, choose M here: the |
114 | module will be called cpufreq_performance. | |
115 | ||
1da177e4 LT |
116 | If in doubt, say Y. |
117 | ||
118 | config CPU_FREQ_GOV_POWERSAVE | |
9101be53 MF |
119 | tristate "'powersave' governor" |
120 | help | |
1da177e4 LT |
121 | This cpufreq governor sets the frequency statically to the |
122 | lowest available CPU frequency. | |
123 | ||
9101be53 MF |
124 | To compile this driver as a module, choose M here: the |
125 | module will be called cpufreq_powersave. | |
126 | ||
1da177e4 LT |
127 | If in doubt, say Y. |
128 | ||
129 | config CPU_FREQ_GOV_USERSPACE | |
9101be53 MF |
130 | tristate "'userspace' governor for userspace frequency scaling" |
131 | help | |
1da177e4 | 132 | Enable this cpufreq governor when you either want to set the |
0211a9c8 | 133 | CPU frequency manually or when a userspace program shall |
1da177e4 | 134 | be able to set the CPU dynamically, like on LART |
4c41251e | 135 | <http://www.lartmaker.nl/>. |
1da177e4 | 136 | |
9101be53 MF |
137 | To compile this driver as a module, choose M here: the |
138 | module will be called cpufreq_userspace. | |
139 | ||
1da177e4 LT |
140 | For details, take a look at <file:Documentation/cpu-freq/>. |
141 | ||
142 | If in doubt, say Y. | |
143 | ||
144 | config CPU_FREQ_GOV_ONDEMAND | |
145 | tristate "'ondemand' cpufreq policy governor" | |
6af6e1ef | 146 | select CPU_FREQ_TABLE |
1e15f295 | 147 | select CPU_FREQ_GOV_COMMON |
1da177e4 LT |
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 | ||
9101be53 MF |
156 | To compile this driver as a module, choose M here: the |
157 | module will be called cpufreq_ondemand. | |
158 | ||
1da177e4 LT |
159 | For details, take a look at linux/Documentation/cpu-freq. |
160 | ||
161 | If in doubt, say N. | |
162 | ||
b9170836 DJ |
163 | config CPU_FREQ_GOV_CONSERVATIVE |
164 | tristate "'conservative' cpufreq governor" | |
165 | depends on CPU_FREQ | |
1e15f295 | 166 | select CPU_FREQ_GOV_COMMON |
b9170836 DJ |
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 | ||
9101be53 MF |
180 | To compile this driver as a module, choose M here: the |
181 | module will be called cpufreq_conservative. | |
182 | ||
b9170836 DJ |
183 | For details, take a look at linux/Documentation/cpu-freq. |
184 | ||
185 | If in doubt, say N. | |
186 | ||
95ceafd4 | 187 | config GENERIC_CPUFREQ_CPU0 |
5553f9e2 | 188 | tristate "Generic CPU0 cpufreq driver" |
95ceafd4 SG |
189 | depends on HAVE_CLK && REGULATOR && PM_OPP && OF |
190 | select CPU_FREQ_TABLE | |
191 | help | |
192 | This adds a generic cpufreq driver for CPU0 frequency management. | |
193 | It supports both uniprocessor (UP) and symmetric multiprocessor (SMP) | |
194 | systems which share clock and voltage across all CPUs. | |
195 | ||
196 | If in doubt, say N. | |
197 | ||
bb0a56ec DJ |
198 | menu "x86 CPU frequency scaling drivers" |
199 | depends on X86 | |
200 | source "drivers/cpufreq/Kconfig.x86" | |
201 | endmenu | |
202 | ||
f7d77079 KK |
203 | menu "ARM CPU frequency scaling drivers" |
204 | depends on ARM | |
205 | source "drivers/cpufreq/Kconfig.arm" | |
206 | endmenu | |
207 | ||
5d8c6658 DES |
208 | menu "PowerPC CPU frequency scaling drivers" |
209 | depends on PPC32 || PPC64 | |
210 | source "drivers/cpufreq/Kconfig.powerpc" | |
211 | endmenu | |
212 | ||
bb0a56ec DJ |
213 | endif |
214 | endmenu |