summaryrefslogtreecommitdiffstats
path: root/Documentation/hwmon/adm1025
diff options
context:
space:
mode:
Diffstat (limited to 'Documentation/hwmon/adm1025')
-rw-r--r--Documentation/hwmon/adm102551
1 files changed, 51 insertions, 0 deletions
diff --git a/Documentation/hwmon/adm1025 b/Documentation/hwmon/adm1025
new file mode 100644
index 00000000000..39d2b781b5d
--- /dev/null
+++ b/Documentation/hwmon/adm1025
@@ -0,0 +1,51 @@
+Kernel driver adm1025
+=====================
+
+Supported chips:
+ * Analog Devices ADM1025, ADM1025A
+ Prefix: 'adm1025'
+ Addresses scanned: I2C 0x2c - 0x2e
+ Datasheet: Publicly available at the Analog Devices website
+ * Philips NE1619
+ Prefix: 'ne1619'
+ Addresses scanned: I2C 0x2c - 0x2d
+ Datasheet: Publicly available at the Philips website
+
+The NE1619 presents some differences with the original ADM1025:
+ * Only two possible addresses (0x2c - 0x2d).
+ * No temperature offset register, but we don't use it anyway.
+ * No INT mode for pin 16. We don't play with it anyway.
+
+Authors:
+ Chen-Yuan Wu <gwu@esoft.com>,
+ Jean Delvare <khali@linux-fr.org>
+
+Description
+-----------
+
+(This is from Analog Devices.) The ADM1025 is a complete system hardware
+monitor for microprocessor-based systems, providing measurement and limit
+comparison of various system parameters. Five voltage measurement inputs
+are provided, for monitoring +2.5V, +3.3V, +5V and +12V power supplies and
+the processor core voltage. The ADM1025 can monitor a sixth power-supply
+voltage by measuring its own VCC. One input (two pins) is dedicated to a
+remote temperature-sensing diode and an on-chip temperature sensor allows
+ambient temperature to be monitored.
+
+One specificity of this chip is that the pin 11 can be hardwired in two
+different manners. It can act as the +12V power-supply voltage analog
+input, or as the a fifth digital entry for the VID reading (bit 4). It's
+kind of strange since both are useful, and the reason for designing the
+chip that way is obscure at least to me. The bit 5 of the configuration
+register can be used to define how the chip is hardwired. Please note that
+it is not a choice you have to make as the user. The choice was already
+made by your motherboard's maker. If the configuration bit isn't set
+properly, you'll have a wrong +12V reading or a wrong VID reading. The way
+the driver handles that is to preserve this bit through the initialization
+process, assuming that the BIOS set it up properly beforehand. If it turns
+out not to be true in some cases, we'll provide a module parameter to force
+modes.
+
+This driver also supports the ADM1025A, which differs from the ADM1025
+only in that it has "open-drain VID inputs while the ADM1025 has on-chip
+100k pull-ups on the VID inputs". It doesn't make any difference for us.