| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | config CPU_FREQ | 
 | 2 | 	bool "CPU Frequency scaling" | 
 | 3 | 	help | 
 | 4 | 	  CPU Frequency scaling allows you to change the clock speed of  | 
 | 5 | 	  CPUs on the fly. This is a nice method to save power, because  | 
 | 6 | 	  the lower the CPU clock speed, the less power the CPU consumes. | 
 | 7 |  | 
 | 8 | 	  Note that this driver doesn't automatically change the CPU | 
 | 9 | 	  clock speed, you need to either enable a dynamic cpufreq governor | 
 | 10 | 	  (see below) after boot, or use a userspace tool. | 
 | 11 |  | 
 | 12 | 	  For details, take a look at <file:Documentation/cpu-freq>. | 
 | 13 |  | 
 | 14 | 	  If in doubt, say N. | 
 | 15 |  | 
 | 16 | if CPU_FREQ | 
 | 17 |  | 
 | 18 | config CPU_FREQ_TABLE | 
 | 19 |        def_tristate m | 
 | 20 |  | 
 | 21 | config CPU_FREQ_DEBUG | 
 | 22 | 	bool "Enable CPUfreq debugging" | 
 | 23 | 	help | 
 | 24 | 	  Say Y here to enable CPUfreq subsystem (including drivers) | 
 | 25 | 	  debugging. You will need to activate it via the kernel | 
 | 26 | 	  command line by passing | 
 | 27 | 	     cpufreq.debug=<value> | 
 | 28 |  | 
 | 29 | 	  To get <value>, add  | 
 | 30 | 	       1 to activate CPUfreq core debugging, | 
 | 31 | 	       2 to activate CPUfreq drivers debugging, and | 
 | 32 | 	       4 to activate CPUfreq governor debugging | 
 | 33 |  | 
 | 34 | config CPU_FREQ_STAT | 
 | 35 |        tristate "CPU frequency translation statistics" | 
 | 36 |        select CPU_FREQ_TABLE | 
 | 37 |        default y | 
 | 38 |        help | 
 | 39 |          This driver exports CPU frequency statistics information through sysfs | 
 | 40 |          file system | 
 | 41 |  | 
 | 42 | config CPU_FREQ_STAT_DETAILS | 
 | 43 |        bool "CPU frequency translation statistics details" | 
 | 44 |        depends on CPU_FREQ_STAT | 
 | 45 |        help | 
 | 46 |          This will show detail CPU frequency translation table in sysfs file | 
 | 47 |          system | 
 | 48 |  | 
| Dave Jones | 3310010 | 2005-05-31 19:03:44 -0700 | [diff] [blame] | 49 | # Note that it is not currently possible to set the other governors (such as ondemand) | 
 | 50 | # as the default, since if they fail to initialise, cpufreq will be | 
 | 51 | # left in an undefined state. | 
 | 52 |  | 
| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 53 | choice | 
 | 54 | 	prompt "Default CPUFreq governor" | 
 | 55 | 	default CPU_FREQ_DEFAULT_GOV_USERSPACE if CPU_FREQ_SA1100 || CPU_FREQ_SA1110 | 
 | 56 | 	default CPU_FREQ_DEFAULT_GOV_PERFORMANCE | 
 | 57 | 	help | 
 | 58 | 	  This option sets which CPUFreq governor shall be loaded at | 
 | 59 | 	  startup. If in doubt, select 'performance'. | 
 | 60 |  | 
 | 61 | config CPU_FREQ_DEFAULT_GOV_PERFORMANCE | 
 | 62 | 	bool "performance" | 
 | 63 | 	select CPU_FREQ_GOV_PERFORMANCE | 
 | 64 | 	help | 
 | 65 | 	  Use the CPUFreq governor 'performance' as default. This sets | 
 | 66 | 	  the frequency statically to the highest frequency supported by | 
 | 67 | 	  the CPU. | 
 | 68 |  | 
 | 69 | config CPU_FREQ_DEFAULT_GOV_USERSPACE | 
 | 70 | 	bool "userspace" | 
 | 71 | 	select CPU_FREQ_GOV_USERSPACE | 
 | 72 | 	help | 
 | 73 | 	  Use the CPUFreq governor 'userspace' as default. This allows | 
 | 74 | 	  you to set the CPU frequency manually or when an userspace  | 
 | 75 | 	  program shall be able to set the CPU dynamically without having | 
 | 76 | 	  to enable the userspace governor manually. | 
 | 77 |  | 
 | 78 | endchoice | 
 | 79 |  | 
 | 80 | config CPU_FREQ_GOV_PERFORMANCE | 
 | 81 |        tristate "'performance' governor" | 
 | 82 |        help | 
 | 83 | 	  This cpufreq governor sets the frequency statically to the | 
 | 84 | 	  highest available CPU frequency. | 
 | 85 |  | 
 | 86 | 	  If in doubt, say Y. | 
 | 87 |  | 
 | 88 | config CPU_FREQ_GOV_POWERSAVE | 
 | 89 |        tristate "'powersave' governor" | 
 | 90 |        help | 
 | 91 | 	  This cpufreq governor sets the frequency statically to the | 
 | 92 | 	  lowest available CPU frequency. | 
 | 93 |  | 
 | 94 | 	  If in doubt, say Y. | 
 | 95 |  | 
 | 96 | config CPU_FREQ_GOV_USERSPACE | 
 | 97 |        tristate "'userspace' governor for userspace frequency scaling" | 
 | 98 |        help | 
 | 99 | 	  Enable this cpufreq governor when you either want to set the | 
 | 100 | 	  CPU frequency manually or when an userspace program shall | 
 | 101 | 	  be able to set the CPU dynamically, like on LART  | 
| Erik Mouw | 4c41251 | 2006-04-03 14:21:00 +0200 | [diff] [blame] | 102 | 	  <http://www.lartmaker.nl/>. | 
| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 103 |  | 
 | 104 | 	  For details, take a look at <file:Documentation/cpu-freq/>. | 
 | 105 |  | 
 | 106 | 	  If in doubt, say Y. | 
 | 107 |  | 
 | 108 | config CPU_FREQ_GOV_ONDEMAND | 
 | 109 | 	tristate "'ondemand' cpufreq policy governor" | 
| Dave Jones | 6af6e1e | 2006-11-21 16:58:59 -0500 | [diff] [blame] | 110 | 	select CPU_FREQ_TABLE | 
| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 111 | 	help | 
 | 112 | 	  'ondemand' - This driver adds a dynamic cpufreq policy governor. | 
 | 113 | 	  The governor does a periodic polling and  | 
 | 114 | 	  changes frequency based on the CPU utilization. | 
 | 115 | 	  The support for this governor depends on CPU capability to | 
 | 116 | 	  do fast frequency switching (i.e, very low latency frequency | 
 | 117 | 	  transitions).  | 
 | 118 |  | 
 | 119 | 	  For details, take a look at linux/Documentation/cpu-freq. | 
 | 120 |  | 
 | 121 | 	  If in doubt, say N. | 
 | 122 |  | 
| Dave Jones | b917083 | 2005-05-31 19:03:47 -0700 | [diff] [blame] | 123 | config CPU_FREQ_GOV_CONSERVATIVE | 
 | 124 | 	tristate "'conservative' cpufreq governor" | 
 | 125 | 	depends on CPU_FREQ | 
 | 126 | 	help | 
 | 127 | 	  'conservative' - this driver is rather similar to the 'ondemand' | 
 | 128 | 	  governor both in its source code and its purpose, the difference is | 
 | 129 | 	  its optimisation for better suitability in a battery powered | 
 | 130 | 	  environment.  The frequency is gracefully increased and decreased | 
 | 131 | 	  rather than jumping to 100% when speed is required. | 
 | 132 |  | 
 | 133 | 	  If you have a desktop machine then you should really be considering | 
 | 134 | 	  the 'ondemand' governor instead, however if you are using a laptop, | 
 | 135 | 	  PDA or even an AMD64 based computer (due to the unacceptable | 
 | 136 | 	  step-by-step latency issues between the minimum and maximum frequency | 
 | 137 | 	  transitions in the CPU) you will probably want to use this governor. | 
 | 138 |  | 
 | 139 | 	  For details, take a look at linux/Documentation/cpu-freq. | 
 | 140 |  | 
 | 141 | 	  If in doubt, say N. | 
 | 142 |  | 
| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 143 | endif	# CPU_FREQ |