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author | Thomas Gleixner <tglx@linutronix.de> | 2009-05-20 09:02:28 +0200 |
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committer | Thomas Gleixner <tglx@linutronix.de> | 2009-05-20 09:02:28 +0200 |
commit | 521c180874dae86f675d23c4eade4dba8b1f2cc8 (patch) | |
tree | 7509303da3a9a1b40a26f6811f321c89cd31737b /Documentation/hwmon/g760a | |
parent | f1a11e0576c7a73d759d05d776692b2b2d37172b (diff) | |
parent | 64d1304a64477629cb16b75491a77bafe6f86963 (diff) |
Merge branch 'core/urgent' into core/futexes
Merge reason: this branch was on an pre -rc1 base, merge it up to -rc6+
to get the latest upstream fixes.
Conflicts:
kernel/futex.c
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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. |