Commit | Line | Data |
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7f15b664 M |
1 | Kernel driver gl518sm |
2 | ===================== | |
3 | ||
4 | Supported chips: | |
b04f2f7d | 5 | |
7f15b664 | 6 | * Genesys Logic GL518SM release 0x00 |
b04f2f7d | 7 | |
7f15b664 | 8 | Prefix: 'gl518sm' |
b04f2f7d | 9 | |
7f15b664 | 10 | Addresses scanned: I2C 0x2c and 0x2d |
b04f2f7d | 11 | |
7f15b664 | 12 | * Genesys Logic GL518SM release 0x80 |
b04f2f7d | 13 | |
7f15b664 | 14 | Prefix: 'gl518sm' |
b04f2f7d | 15 | |
7f15b664 | 16 | Addresses scanned: I2C 0x2c and 0x2d |
b04f2f7d | 17 | |
0ea6e611 | 18 | Datasheet: http://www.genesyslogic.com/ |
7f15b664 M |
19 | |
20 | Authors: | |
b04f2f7d MCC |
21 | - Frodo Looijaard <frodol@dds.nl>, |
22 | - Kyösti Mälkki <kmalkki@cc.hut.fi> | |
23 | - Hong-Gunn Chew <hglinux@gunnet.org> | |
24 | - Jean Delvare <jdelvare@suse.de> | |
7f15b664 M |
25 | |
26 | Description | |
27 | ----------- | |
28 | ||
b04f2f7d | 29 | .. important:: |
7f15b664 | 30 | |
b04f2f7d MCC |
31 | For the revision 0x00 chip, the in0, in1, and in2 values (+5V, +3V, |
32 | and +12V) CANNOT be read. This is a limitation of the chip, not the driver. | |
7f15b664 M |
33 | |
34 | This driver supports the Genesys Logic GL518SM chip. There are at least | |
35 | two revision of this chip, which we call revision 0x00 and 0x80. Revision | |
36 | 0x80 chips support the reading of all voltages and revision 0x00 only | |
37 | for VIN3. | |
38 | ||
39 | The GL518SM implements one temperature sensor, two fan rotation speed | |
40 | sensors, and four voltage sensors. It can report alarms through the | |
41 | computer speakers. | |
42 | ||
43 | Temperatures are measured in degrees Celsius. An alarm goes off while the | |
44 | temperature is above the over temperature limit, and has not yet dropped | |
45 | below the hysteresis limit. The alarm always reflects the current | |
46 | situation. Measurements are guaranteed between -10 degrees and +110 | |
47 | degrees, with a accuracy of +/-3 degrees. | |
48 | ||
49 | Rotation speeds are reported in RPM (rotations per minute). An alarm is | |
50 | triggered if the rotation speed has dropped below a programmable limit. In | |
51 | case when you have selected to turn fan1 off, no fan1 alarm is triggered. | |
52 | ||
53 | Fan readings can be divided by a programmable divider (1, 2, 4 or 8) to | |
54 | give the readings more range or accuracy. Not all RPM values can | |
55 | accurately be represented, so some rounding is done. With a divider | |
56 | of 2, the lowest representable value is around 1900 RPM. | |
57 | ||
58 | Voltage sensors (also known as VIN sensors) report their values in volts. | |
59 | An alarm is triggered if the voltage has crossed a programmable minimum or | |
60 | maximum limit. Note that minimum in this case always means 'closest to | |
61 | zero'; this is important for negative voltage measurements. The VDD input | |
62 | measures voltages between 0.000 and 5.865 volt, with a resolution of 0.023 | |
63 | volt. The other inputs measure voltages between 0.000 and 4.845 volt, with | |
64 | a resolution of 0.019 volt. Note that revision 0x00 chips do not support | |
65 | reading the current voltage of any input except for VIN3; limit setting and | |
66 | alarms work fine, though. | |
67 | ||
68 | When an alarm is triggered, you can be warned by a beeping signal through your | |
69 | computer speaker. It is possible to enable all beeping globally, or only the | |
70 | beeping for some alarms. | |
71 | ||
72 | If an alarm triggers, it will remain triggered until the hardware register | |
73 | is read at least once (except for temperature alarms). This means that the | |
74 | cause for the alarm may already have disappeared! Note that in the current | |
75 | implementation, all hardware registers are read whenever any data is read | |
76 | (unless it is less than 1.5 seconds since the last update). This means that | |
77 | you can easily miss once-only alarms. | |
78 | ||
79 | The GL518SM only updates its values each 1.5 seconds; reading it more often | |
80 | will do no harm, but will return 'old' values. |