(Phil) Added a driver for the LTC1710. The LTC1710 is a very simple dual

switch.  It can switch two devices which each consume 300mA at 5V (or less).
This is good for fans, lights, or into relays for heftier stuff.

Here's what the usage looks like:

[root@penn sensors]# ls ltc1710-i2c-1-58/*
ltc1710-i2c-1-58/switch1
ltc1710-i2c-1-58/switch2

[root@penn sensors]# cat ltc1710-i2c-1-58/*
0
0

[root@penn sensors]# echo "1" >  ltc1710-i2c-1-58/switch2
(blue LED turned on)

[root@penn sensors]# cat ltc1710-i2c-1-58/*
0
1

One problem with the device: It doesn't support reads.  It ignores any
read transactions, so even detection with a read won't work.  This
also means that the status of the switches has to be remembered and
can't be polled.

As simple as this device is, it is one of the few which actually
allows the computer to send signals OUT into the world to
control something.


git-svn-id: http://lm-sensors.org/svn/lm-sensors/trunk@155 7894878c-1315-0410-8ee3-d5d059ff63e0

kernel/include/sensors.h

@@ -90,6 +90,7 @@ extern void sensors_deregister_entry(int id);
 #define I2C_DRIVERID_LM80 1007
 #define I2C_DRIVERID_ADM1021 1008
 #define I2C_DRIVERID_ADM9240 1009
+#define I2C_DRIVERID_LTC1710 1010
 
 /* Sysctl IDs */
 #ifdef DEV_HWMON
@@ -230,6 +231,9 @@ struct sensors_chips_data {
 #define ADM9240_SYSCTL_ALARMS 2001 /* bitvector */
 #define ADM9240_SYSCTL_ANALOG_OUT 2002
 
+#define LTC1710_SYSCTL_SWITCH_1 1000
+#define LTC1710_SYSCTL_SWITCH_2 1001
+
 #define LM80_ALARM_IN0 0x0001
 #define LM80_ALARM_IN1 0x0002
 #define LM80_ALARM_IN2 0x0004