hwmon: Add LTC4215 driver

Add Linux support for the Linear Technology LTC4215 Hot Swap controller
I2C monitoring interface.

I have tested the driver with my board, and it appears to work fine.  With
the power supplies disabled, it reads 11.93V input, 1.93V output, no
current and no power.  With the supplies enabled, it reads 11.93V input,
11.98V output, no current, no power.  I'm not drawing any current at the
moment, so this is reasonable.  The value in the sense register never
reads anything except 0, so I expect to get zero from the current and
power calculations.

I didn't attempt to support changing any of the chip's settings or
enabling the FET.  I'm not sure even how to do that and still fit within
the hwmon framework.  :)

Signed-off-by: Ira W. Snyder <iws@ovro.caltech.edu>
Cc: Jean Delvare <khali@linux-fr.org>
Cc: "Mark M. Hoffman" <mhoffman@lightlink.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 11 insertions, 0 deletions

diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index 8a91c9971558..bc6810c22dd7 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -571,6 +571,17 @@ config SENSORS_LM93
           This driver can also be built as a module.  If so, the module
           will be called lm93.
 
+config SENSORS_LTC4215
+        tristate "Linear Technology LTC4215"
+        depends on I2C && EXPERIMENTAL
+        default n
+        help
+          If you say yes here you get support for Linear Technology LTC4215
+          Hot Swap Controller I2C interface.
+
+          This driver can also be built as a module. If so, the module will
+          be called ltc4215.
+
 config SENSORS_LTC4245
         tristate "Linear Technology LTC4245"
         depends on I2C && EXPERIMENTAL