xref: /linux/Documentation/hwmon/adm1025.rst (revision c39f2d9db0fd81ea20bb5cce9b3f082ca63753e2)
1*7ebd8b66SMauro Carvalho ChehabKernel driver adm1025
2*7ebd8b66SMauro Carvalho Chehab=====================
3*7ebd8b66SMauro Carvalho Chehab
4*7ebd8b66SMauro Carvalho ChehabSupported chips:
5*7ebd8b66SMauro Carvalho Chehab
6*7ebd8b66SMauro Carvalho Chehab  * Analog Devices ADM1025, ADM1025A
7*7ebd8b66SMauro Carvalho Chehab
8*7ebd8b66SMauro Carvalho Chehab    Prefix: 'adm1025'
9*7ebd8b66SMauro Carvalho Chehab
10*7ebd8b66SMauro Carvalho Chehab    Addresses scanned: I2C 0x2c - 0x2e
11*7ebd8b66SMauro Carvalho Chehab
12*7ebd8b66SMauro Carvalho Chehab    Datasheet: Publicly available at the Analog Devices website
13*7ebd8b66SMauro Carvalho Chehab
14*7ebd8b66SMauro Carvalho Chehab  * Philips NE1619
15*7ebd8b66SMauro Carvalho Chehab
16*7ebd8b66SMauro Carvalho Chehab    Prefix: 'ne1619'
17*7ebd8b66SMauro Carvalho Chehab
18*7ebd8b66SMauro Carvalho Chehab    Addresses scanned: I2C 0x2c - 0x2d
19*7ebd8b66SMauro Carvalho Chehab
20*7ebd8b66SMauro Carvalho Chehab    Datasheet: Publicly available at the Philips website
21*7ebd8b66SMauro Carvalho Chehab
22*7ebd8b66SMauro Carvalho ChehabThe NE1619 presents some differences with the original ADM1025:
23*7ebd8b66SMauro Carvalho Chehab
24*7ebd8b66SMauro Carvalho Chehab  * Only two possible addresses (0x2c - 0x2d).
25*7ebd8b66SMauro Carvalho Chehab  * No temperature offset register, but we don't use it anyway.
26*7ebd8b66SMauro Carvalho Chehab  * No INT mode for pin 16. We don't play with it anyway.
27*7ebd8b66SMauro Carvalho Chehab
28*7ebd8b66SMauro Carvalho ChehabAuthors:
29*7ebd8b66SMauro Carvalho Chehab	- Chen-Yuan Wu <gwu@esoft.com>,
30*7ebd8b66SMauro Carvalho Chehab	- Jean Delvare <jdelvare@suse.de>
31*7ebd8b66SMauro Carvalho Chehab
32*7ebd8b66SMauro Carvalho ChehabDescription
33*7ebd8b66SMauro Carvalho Chehab-----------
34*7ebd8b66SMauro Carvalho Chehab
35*7ebd8b66SMauro Carvalho Chehab(This is from Analog Devices.) The ADM1025 is a complete system hardware
36*7ebd8b66SMauro Carvalho Chehabmonitor for microprocessor-based systems, providing measurement and limit
37*7ebd8b66SMauro Carvalho Chehabcomparison of various system parameters. Five voltage measurement inputs
38*7ebd8b66SMauro Carvalho Chehabare provided, for monitoring +2.5V, +3.3V, +5V and +12V power supplies and
39*7ebd8b66SMauro Carvalho Chehabthe processor core voltage. The ADM1025 can monitor a sixth power-supply
40*7ebd8b66SMauro Carvalho Chehabvoltage by measuring its own VCC. One input (two pins) is dedicated to a
41*7ebd8b66SMauro Carvalho Chehabremote temperature-sensing diode and an on-chip temperature sensor allows
42*7ebd8b66SMauro Carvalho Chehabambient temperature to be monitored.
43*7ebd8b66SMauro Carvalho Chehab
44*7ebd8b66SMauro Carvalho ChehabOne specificity of this chip is that the pin 11 can be hardwired in two
45*7ebd8b66SMauro Carvalho Chehabdifferent manners. It can act as the +12V power-supply voltage analog
46*7ebd8b66SMauro Carvalho Chehabinput, or as the a fifth digital entry for the VID reading (bit 4). It's
47*7ebd8b66SMauro Carvalho Chehabkind of strange since both are useful, and the reason for designing the
48*7ebd8b66SMauro Carvalho Chehabchip that way is obscure at least to me. The bit 5 of the configuration
49*7ebd8b66SMauro Carvalho Chehabregister can be used to define how the chip is hardwired. Please note that
50*7ebd8b66SMauro Carvalho Chehabit is not a choice you have to make as the user. The choice was already
51*7ebd8b66SMauro Carvalho Chehabmade by your motherboard's maker. If the configuration bit isn't set
52*7ebd8b66SMauro Carvalho Chehabproperly, you'll have a wrong +12V reading or a wrong VID reading. The way
53*7ebd8b66SMauro Carvalho Chehabthe driver handles that is to preserve this bit through the initialization
54*7ebd8b66SMauro Carvalho Chehabprocess, assuming that the BIOS set it up properly beforehand. If it turns
55*7ebd8b66SMauro Carvalho Chehabout not to be true in some cases, we'll provide a module parameter to force
56*7ebd8b66SMauro Carvalho Chehabmodes.
57*7ebd8b66SMauro Carvalho Chehab
58*7ebd8b66SMauro Carvalho ChehabThis driver also supports the ADM1025A, which differs from the ADM1025
59*7ebd8b66SMauro Carvalho Chehabonly in that it has "open-drain VID inputs while the ADM1025 has on-chip
60*7ebd8b66SMauro Carvalho Chehab100k pull-ups on the VID inputs". It doesn't make any difference for us.
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