[PATCH] I2C: documentation update 2/3

This patch adds missing documentation for system health monitoring chips.
I would like to thank all people, who helped me with this project.

Signed-off-by: Rudolf Marek <r.marek@sh.cvut.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 51 insertions, 0 deletions

diff --git a/Documentation/i2c/chips/adm1025 b/Documentation/i2c/chips/adm1025
new file mode 100644
index 00000000000..39d2b781b5d
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+++ b/Documentation/i2c/chips/adm1025
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+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.