ARM: tegra: Document sysfs params
[linux-2.6.git] / Documentation / arm / nvidia / tegra_parameters.txt
1 This file documents NVIDIA Tegra specific sysfs and debugfs files and
2 kernel module parameters.
3
4 /sys/power/suspend/mode
5 -----------------------
6
7 Used to select the LP1 or LP0 power state during system suspend.
8 # echo lp0 > /sys/kernel/debug/suspend_mode
9 # echo lp1 > /sys/kernel/debug/suspend_mode
10
11 /sys/module/cpuidle/parameters/lp2_in_idle
12 ------------------------------------------
13
14 Used to enable/disable LP2 in idle.
15 # echo 1 > /sys/module/cpuidle/parameters/lp2_in_idle
16 # echo 0 > /sys/module/cpuidle/parameters/lp2_in_idle
17
18 /sys/kernel/debug/cpuidle/lp2
19 -----------------------------
20
21 Contains LP2 statistics.
22 # cat /sys/kernel/debug/cpuidle/lp2
23
24 /sys/kernel/debug/powergate
25 ---------------------------
26
27 Contains power gating state of different tegra blocks.
28
29 # cat /sys/kernel/debug/powergate
30
31 /sys/devices/system/cpu/cpuquiet/tegra_cpuquiet/enable
32 ------------------------------------------------------
33
34 Control hotplugging of cores.
35 # echo 0 > /sys/devices/system/cpu/cpuquiet/tegra_cpuquiet/enable
36 # echo 1 > /sys/devices/system/cpu/cpuquiet/tegra_cpuquiet/enable
37
38 Cpuquiet supports the implementation of multiple policies in the form of
39 governors. The balanced governor implements the exact same policy previously
40 implemented as "auto hotplug". The behavior with regards to cores coming
41 online/offline and switching between the LP and G cluster remain the same.
42
43 /sys/devices/system/cpu/cpuquiet/tegra_cpuquiet/no_lp
44 -----------------------------------------------------
45
46 Enable/disable shadow cluster.
47 # echo 0 > /sys/devices/system/cpu/cpuquiet/tegra_cpuquiet/no_lp
48 # echo 1 > /sys/devices/system/cpu/cpuquiet/tegra_cpuquiet/no_lp
49
50 /sys/devices/system/cpu/cpuquiet/available_governors
51 ----------------------------------------------------
52
53 List available governors.
54 # cat /sys/devices/system/cpu/cpuquiet/available_governors
55
56 /sys/devices/system/cpu/cpuquiet/current_governor
57 -------------------------------------------------
58
59 Set the current active cpuquiet governor.
60 # echo [governor name] > /sys/devices/system/cpu/cpuquiet/current_governor
61
62 /sys/devices/system/cpu/cpuquiet/tegra_cpuquiet/idle_bottom_freq
63 ----------------------------------------------------------------
64
65 Main cluster minimum frequency.
66
67 /sys/devices/system/cpu/cpuquiet/tegra_cpuquiet/idle_top_freq
68 -------------------------------------------------------------
69
70 Main cluster maximum frequency.
71
72 /sys/devices/system/cpu/cpuquiet/tegra_cpuquiet/down_delay
73 ----------------------------------------------------------
74
75 Delay (in jiffies) for switching to shadow cluster.
76
77 /sys/devices/system/cpu/cpuquiet/tegra_cpuquiet/up_delay
78 --------------------------------------------------------
79
80 Delay for switching to main cluster.
81
82 /sys/devices/system/cpu/cpuquiet/tegra_cpuquiet/mp_overhead
83 -----------------------------------------------------------
84
85 Multi-core overhead percentage for EDP limit calculation.
86
87 /sys/devices/system/cpu/cpuquiet/balanced/balance_level
88 -------------------------------------------------------
89
90 Percentage of max speed considered to be in balance. Half of balanced
91 speed is considered skewed. Requires balanced governor to be set active.
92
93 /sys/devices/system/cpu/cpuquiet/balanced/down_delay
94 ----------------------------------------------------
95
96 Delay for reducing cores. Requires balanced governor to be set active.
97
98 /sys/devices/system/cpu/cpuquiet/balanced/up_delay
99 --------------------------------------------------
100
101 Delay for bringing additional cores online in main cluster. Requires
102 balanced governor to be set active.
103
104 /sys/kernel/debug/tegra_hotplug/stats
105 -------------------------------------
106
107 Contains hotplug statistics.
108
109 /sys/kernel/cluster/active
110 --------------------------
111
112 Controls active CPU cluster: main (G) or shadow (LP).
113 For manual control disable auto hotlug, enable immediate switch and
114 possibly force switch to happen always:
115 # echo 0 > /sys/module/cpu_tegra3/parameters/auto_hotplug
116 # echo 1 > /sys/kernel/cluster/immediate
117 # echo 1 > /sys/kernel/cluster/force
118
119 Cluster switching can happen only when only core 0 is online.
120
121 Active cluster can be set or toggled:
122 # echo "G" > /sys/kernel/cluster/active
123 # echo "LP" > /sys/kernel/cluster/active
124 # echo "toggle" > /sys/kernel/cluster/active
125
126 /sys/module/tegra30_clocks/parameters/detach_shared_bus
127 ------------------------------------------------------
128
129 Enable/disable shared bus clock update.
130
131 /sys/module/tegra3_emc/parameters/emc_enable
132 --------------------------------------------
133
134 Enable/disable EMC DFS.
135
136 /sys/kernel/debug/tegra_emc/stats
137 ---------------------------------
138
139 Contains EMC clock statistics.
140
141 /sys/module/tegra3_dvfs/parameters/disable_cpu
142 ----------------------------------------------
143
144 Enable/disable DVFS for CPU domain.
145
146 /sys/module/tegra3_dvfs/parameters/disable_core
147 -----------------------------------------------
148
149 Enable/disable DVFS for CORE domain.
150
151 /sys/kernel/debug/clock/emc/rate
152 --------------------------------
153
154 Get/set EMC clock rate.
155
156 /sys/kernel/debug/clock/<module>/rate
157 -------------------------------------
158
159 /sys/kernel/debug/clock/<module>/parent
160 ---------------------------------------
161
162 /sys/kernel/debug/clock/<module>/state
163 --------------------------------------
164
165 /sys/kernel/debug/clock/<module>/time_on
166 ----------------------------------------
167
168 /sys/kernel/debug/clock/clock_tree
169 ----------------------------------
170
171 Shows the state of the clock tree.
172
173 /sys/kernel/debug/clock/dvfs
174 ----------------------------
175
176 Contains voltage state.
177
178 /sys/kernel/debug/tegra_actmon/avp/state
179 ----------------------------------------
180
181 /sys/kernel/debug/clock/mon.avp/rate
182 ------------------------------------
183
184 /sys/kernel/debug/clock/rails
185 -----------------------------
186
187 Contains the time at each voltage.
188
189 /sys/devices/system/cpu/cpu0/cpufreq/stats/time_in_state
190 --------------------------------------------------------
191
192 Contains the time at each frequency.