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| author | Ingo Molnar <mingo@elte.hu> | 2009-04-08 10:35:30 +0200 |
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| committer | Ingo Molnar <mingo@elte.hu> | 2009-04-08 10:35:30 +0200 |
| commit | 5ea472a77f8e4811ceee3f44a9deda6ad6e8b789 (patch) | |
| tree | a9ec5019e2b666a19874fc344ffb0dd5da6bce94 /Documentation/hwmon/g760a | |
| parent | 6c009ecef8cca28c7c09eb16d0802e37915a76e1 (diff) | |
| parent | 577c9c456f0e1371cbade38eaf91ae8e8a308555 (diff) | |
| download | kernel-crypto-5ea472a77f8e4811ceee3f44a9deda6ad6e8b789.tar.gz kernel-crypto-5ea472a77f8e4811ceee3f44a9deda6ad6e8b789.tar.xz kernel-crypto-5ea472a77f8e4811ceee3f44a9deda6ad6e8b789.zip | |
Merge commit 'v2.6.30-rc1' into perfcounters/core
Conflicts:
arch/powerpc/include/asm/systbl.h
arch/powerpc/include/asm/unistd.h
include/linux/init_task.h
Merge reason: the conflicts are non-trivial: PowerPC placement
of sys_perf_counter_open has to be mixed with the
new preadv/pwrite syscalls.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'Documentation/hwmon/g760a')
| -rw-r--r-- | Documentation/hwmon/g760a | 36 |
1 files changed, 36 insertions, 0 deletions
diff --git a/Documentation/hwmon/g760a b/Documentation/hwmon/g760a new file mode 100644 index 00000000000..e032eeb7562 --- /dev/null +++ b/Documentation/hwmon/g760a @@ -0,0 +1,36 @@ +Kernel driver g760a +=================== + +Supported chips: + * Global Mixed-mode Technology Inc. G760A + Prefix: 'g760a' + Datasheet: Publicly available at the GMT website + http://www.gmt.com.tw/datasheet/g760a.pdf + +Author: Herbert Valerio Riedel <hvr@gnu.org> + +Description +----------- + +The GMT G760A Fan Speed PWM Controller is connected directly to a fan +and performs closed-loop control of the fan speed. + +The fan speed is programmed by setting the period via 'pwm1' of two +consecutive speed pulses. The period is defined in terms of clock +cycle counts of an assumed 32kHz clock source. + +Setting a period of 0 stops the fan; setting the period to 255 sets +fan to maximum speed. + +The measured fan rotation speed returned via 'fan1_input' is derived +from the measured speed pulse period by assuming again a 32kHz clock +source and a 2 pulse-per-revolution fan. + +The 'alarms' file provides access to the two alarm bits provided by +the G760A chip's status register: Bit 0 is set when the actual fan +speed differs more than 20% with respect to the programmed fan speed; +bit 1 is set when fan speed is below 1920 RPM. + +The g760a driver will not update its values more frequently than every +other second; reading them more often will do no harm, but will return +'old' values. |