xref: /OK3568_Linux_fs/kernel/Documentation/hwmon/lm95245.rst (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593SmuzhiyunKernel driver lm95245
2*4882a593Smuzhiyun=====================
3*4882a593Smuzhiyun
4*4882a593SmuzhiyunSupported chips:
5*4882a593Smuzhiyun
6*4882a593Smuzhiyun  * TI LM95235
7*4882a593Smuzhiyun
8*4882a593Smuzhiyun    Addresses scanned: I2C 0x18, 0x29, 0x4c
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10*4882a593Smuzhiyun    Datasheet: Publicly available at the TI website
11*4882a593Smuzhiyun
12*4882a593Smuzhiyun	       https://www.ti.com/lit/ds/symlink/lm95235.pdf
13*4882a593Smuzhiyun
14*4882a593Smuzhiyun  * TI / National Semiconductor LM95245
15*4882a593Smuzhiyun
16*4882a593Smuzhiyun    Addresses scanned: I2C 0x18, 0x19, 0x29, 0x4c, 0x4d
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18*4882a593Smuzhiyun    Datasheet: Publicly available at the TI website
19*4882a593Smuzhiyun
20*4882a593Smuzhiyun	       https://www.ti.com/lit/ds/symlink/lm95245.pdf
21*4882a593Smuzhiyun
22*4882a593SmuzhiyunAuthor: Alexander Stein <alexander.stein@systec-electronic.com>
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24*4882a593SmuzhiyunDescription
25*4882a593Smuzhiyun-----------
26*4882a593Smuzhiyun
27*4882a593SmuzhiyunLM95235 and LM95245 are 11-bit digital temperature sensors with a 2-wire System
28*4882a593SmuzhiyunManagement Bus (SMBus) interface and TruTherm technology that can monitor
29*4882a593Smuzhiyunthe temperature of a remote diode as well as its own temperature.
30*4882a593SmuzhiyunThe chips can be used to very accurately monitor the temperature of
31*4882a593Smuzhiyunexternal devices such as microprocessors.
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33*4882a593SmuzhiyunAll temperature values are given in millidegrees Celsius. Local temperature
34*4882a593Smuzhiyunis given within a range of -127 to +127.875 degrees. Remote temperatures are
35*4882a593Smuzhiyungiven within a range of -127 to +255 degrees. Resolution depends on
36*4882a593Smuzhiyuntemperature input and range.
37*4882a593Smuzhiyun
38*4882a593SmuzhiyunEach sensor has its own critical limit. Additionally, there is a relative
39*4882a593Smuzhiyunhysteresis value common to both critical limits. To make life easier to
40*4882a593Smuzhiyunuser-space applications, two absolute values are exported, one for each
41*4882a593Smuzhiyunchannel, but these values are of course linked. Only the local hysteresis
42*4882a593Smuzhiyuncan be set from user-space, and the same delta applies to the remote
43*4882a593Smuzhiyunhysteresis.
44*4882a593Smuzhiyun
45*4882a593SmuzhiyunThe lm95245 driver can change its update interval to a fixed set of values.
46*4882a593SmuzhiyunIt will round up to the next selectable interval. See the datasheet for exact
47*4882a593Smuzhiyunvalues. Reading sensor values more often will do no harm, but will return
48*4882a593Smuzhiyun'old' values.
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