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