xref: /OK3568_Linux_fs/kernel/Documentation/hwmon/adm1025.rst (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593SmuzhiyunKernel driver adm1025
2*4882a593Smuzhiyun=====================
3*4882a593Smuzhiyun
4*4882a593SmuzhiyunSupported chips:
5*4882a593Smuzhiyun
6*4882a593Smuzhiyun  * Analog Devices ADM1025, ADM1025A
7*4882a593Smuzhiyun
8*4882a593Smuzhiyun    Prefix: 'adm1025'
9*4882a593Smuzhiyun
10*4882a593Smuzhiyun    Addresses scanned: I2C 0x2c - 0x2e
11*4882a593Smuzhiyun
12*4882a593Smuzhiyun    Datasheet: Publicly available at the Analog Devices website
13*4882a593Smuzhiyun
14*4882a593Smuzhiyun  * Philips NE1619
15*4882a593Smuzhiyun
16*4882a593Smuzhiyun    Prefix: 'ne1619'
17*4882a593Smuzhiyun
18*4882a593Smuzhiyun    Addresses scanned: I2C 0x2c - 0x2d
19*4882a593Smuzhiyun
20*4882a593Smuzhiyun    Datasheet: Publicly available at the Philips website
21*4882a593Smuzhiyun
22*4882a593SmuzhiyunThe NE1619 presents some differences with the original ADM1025:
23*4882a593Smuzhiyun
24*4882a593Smuzhiyun  * Only two possible addresses (0x2c - 0x2d).
25*4882a593Smuzhiyun  * No temperature offset register, but we don't use it anyway.
26*4882a593Smuzhiyun  * No INT mode for pin 16. We don't play with it anyway.
27*4882a593Smuzhiyun
28*4882a593SmuzhiyunAuthors:
29*4882a593Smuzhiyun	- Chen-Yuan Wu <gwu@esoft.com>,
30*4882a593Smuzhiyun	- Jean Delvare <jdelvare@suse.de>
31*4882a593Smuzhiyun
32*4882a593SmuzhiyunDescription
33*4882a593Smuzhiyun-----------
34*4882a593Smuzhiyun
35*4882a593Smuzhiyun(This is from Analog Devices.) The ADM1025 is a complete system hardware
36*4882a593Smuzhiyunmonitor for microprocessor-based systems, providing measurement and limit
37*4882a593Smuzhiyuncomparison of various system parameters. Five voltage measurement inputs
38*4882a593Smuzhiyunare provided, for monitoring +2.5V, +3.3V, +5V and +12V power supplies and
39*4882a593Smuzhiyunthe processor core voltage. The ADM1025 can monitor a sixth power-supply
40*4882a593Smuzhiyunvoltage by measuring its own VCC. One input (two pins) is dedicated to a
41*4882a593Smuzhiyunremote temperature-sensing diode and an on-chip temperature sensor allows
42*4882a593Smuzhiyunambient temperature to be monitored.
43*4882a593Smuzhiyun
44*4882a593SmuzhiyunOne specificity of this chip is that the pin 11 can be hardwired in two
45*4882a593Smuzhiyundifferent manners. It can act as the +12V power-supply voltage analog
46*4882a593Smuzhiyuninput, or as the a fifth digital entry for the VID reading (bit 4). It's
47*4882a593Smuzhiyunkind of strange since both are useful, and the reason for designing the
48*4882a593Smuzhiyunchip that way is obscure at least to me. The bit 5 of the configuration
49*4882a593Smuzhiyunregister can be used to define how the chip is hardwired. Please note that
50*4882a593Smuzhiyunit is not a choice you have to make as the user. The choice was already
51*4882a593Smuzhiyunmade by your motherboard's maker. If the configuration bit isn't set
52*4882a593Smuzhiyunproperly, you'll have a wrong +12V reading or a wrong VID reading. The way
53*4882a593Smuzhiyunthe driver handles that is to preserve this bit through the initialization
54*4882a593Smuzhiyunprocess, assuming that the BIOS set it up properly beforehand. If it turns
55*4882a593Smuzhiyunout not to be true in some cases, we'll provide a module parameter to force
56*4882a593Smuzhiyunmodes.
57*4882a593Smuzhiyun
58*4882a593SmuzhiyunThis driver also supports the ADM1025A, which differs from the ADM1025
59*4882a593Smuzhiyunonly in that it has "open-drain VID inputs while the ADM1025 has on-chip
60*4882a593Smuzhiyun100k pull-ups on the VID inputs". It doesn't make any difference for us.
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