From ace9429bb58fd418f0c81d4c2835699bddf6bde6 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Thu, 11 Apr 2024 10:27:49 +0200 Subject: Adding upstream version 6.6.15. Signed-off-by: Daniel Baumann --- Documentation/hwmon/g760a.rst | 40 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 40 insertions(+) create mode 100644 Documentation/hwmon/g760a.rst (limited to 'Documentation/hwmon/g760a.rst') diff --git a/Documentation/hwmon/g760a.rst b/Documentation/hwmon/g760a.rst new file mode 100644 index 000000000..d82952cc8 --- /dev/null +++ b/Documentation/hwmon/g760a.rst @@ -0,0 +1,40 @@ +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/product/datasheet/EDS-760A.pdf + +Author: Herbert Valerio Riedel + +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. -- cgit v1.2.3