| Kernel driver ltc4261 | |
| ===================== | |
| Supported chips: | |
| * Linear Technology LTC4261 | |
| Prefix: 'ltc4261' | |
| Addresses scanned: - | |
| Datasheet: | |
| http://cds.linear.com/docs/Datasheet/42612fb.pdf | |
| Author: Guenter Roeck <linux@roeck-us.net> | |
| Description | |
| ----------- | |
| The LTC4261/LTC4261-2 negative voltage Hot Swap controllers allow a board | |
| to be safely inserted and removed from a live backplane. | |
| Usage Notes | |
| ----------- | |
| This driver does not probe for LTC4261 devices, since there is no register | |
| which can be safely used to identify the chip. You will have to instantiate | |
| the devices explicitly. | |
| Example: the following will load the driver for an LTC4261 at address 0x10 | |
| on I2C bus #1: | |
| $ modprobe ltc4261 | |
| $ echo ltc4261 0x10 > /sys/bus/i2c/devices/i2c-1/new_device | |
| Sysfs entries | |
| ------------- | |
| Voltage readings provided by this driver are reported as obtained from the ADC | |
| registers. If a set of voltage divider resistors is installed, calculate the | |
| real voltage by multiplying the reported value with (R1+R2)/R2, where R1 is the | |
| value of the divider resistor against the measured voltage and R2 is the value | |
| of the divider resistor against Ground. | |
| Current reading provided by this driver is reported as obtained from the ADC | |
| Current Sense register. The reported value assumes that a 1 mOhm sense resistor | |
| is installed. If a different sense resistor is installed, calculate the real | |
| current by dividing the reported value by the sense resistor value in mOhm. | |
| The chip has two voltage sensors, but only one set of voltage alarm status bits. | |
| In many many designs, those alarms are associated with the ADIN2 sensor, due to | |
| the proximity of the ADIN2 pin to the OV pin. ADIN2 is, however, not available | |
| on all chip variants. To ensure that the alarm condition is reported to the user, | |
| report it with both voltage sensors. | |
| in1_input ADIN2 voltage (mV) | |
| in1_min_alarm ADIN/ADIN2 Undervoltage alarm | |
| in1_max_alarm ADIN/ADIN2 Overvoltage alarm | |
| in2_input ADIN voltage (mV) | |
| in2_min_alarm ADIN/ADIN2 Undervoltage alarm | |
| in2_max_alarm ADIN/ADIN2 Overvoltage alarm | |
| curr1_input SENSE current (mA) | |
| curr1_alarm SENSE overcurrent alarm |