| Guenter Roeck | 6700ce0 | 2014-01-11 10:28:05 -0800 | [diff] [blame] | 1 | Kernel driver ltc2945 |
| 2 | ===================== |
| 3 | |
| 4 | Supported chips: |
| 5 | * Linear Technology LTC2945 |
| 6 | Prefix: 'ltc2945' |
| 7 | Addresses scanned: - |
| 8 | Datasheet: |
| 9 | http://cds.linear.com/docs/en/datasheet/2945fa.pdf |
| 10 | |
| 11 | Author: Guenter Roeck <linux@roeck-us.net> |
| 12 | |
| 13 | |
| 14 | Description |
| 15 | ----------- |
| 16 | |
| 17 | The LTC2945 is a rail-to-rail system monitor that measures current, voltage, |
| 18 | and power consumption. |
| 19 | |
| 20 | |
| 21 | Usage Notes |
| 22 | ----------- |
| 23 | |
| 24 | This driver does not probe for LTC2945 devices, since there is no register |
| 25 | which can be safely used to identify the chip. You will have to instantiate |
| 26 | the devices explicitly. |
| 27 | |
| 28 | Example: the following will load the driver for an LTC2945 at address 0x10 |
| 29 | on I2C bus #1: |
| 30 | $ modprobe ltc2945 |
| 31 | $ echo ltc2945 0x10 > /sys/bus/i2c/devices/i2c-1/new_device |
| 32 | |
| 33 | |
| 34 | Sysfs entries |
| 35 | ------------- |
| 36 | |
| 37 | Voltage readings provided by this driver are reported as obtained from the ADC |
| 38 | registers. If a set of voltage divider resistors is installed, calculate the |
| 39 | real voltage by multiplying the reported value with (R1+R2)/R2, where R1 is the |
| 40 | value of the divider resistor against the measured voltage and R2 is the value |
| 41 | of the divider resistor against Ground. |
| 42 | |
| 43 | Current reading provided by this driver is reported as obtained from the ADC |
| 44 | Current Sense register. The reported value assumes that a 1 mOhm sense resistor |
| 45 | is installed. If a different sense resistor is installed, calculate the real |
| 46 | current by dividing the reported value by the sense resistor value in mOhm. |
| 47 | |
| 48 | in1_input VIN voltage (mV). Voltage is measured either at |
| 49 | SENSE+ or VDD pin depending on chip configuration. |
| 50 | in1_min Undervoltage threshold |
| 51 | in1_max Overvoltage threshold |
| 52 | in1_lowest Lowest measured voltage |
| 53 | in1_highest Highest measured voltage |
| 54 | in1_reset_history Write 1 to reset in1 history |
| 55 | in1_min_alarm Undervoltage alarm |
| 56 | in1_max_alarm Overvoltage alarm |
| 57 | |
| 58 | in2_input ADIN voltage (mV) |
| 59 | in2_min Undervoltage threshold |
| 60 | in2_max Overvoltage threshold |
| 61 | in2_lowest Lowest measured voltage |
| 62 | in2_highest Highest measured voltage |
| 63 | in2_reset_history Write 1 to reset in2 history |
| 64 | in2_min_alarm Undervoltage alarm |
| 65 | in2_max_alarm Overvoltage alarm |
| 66 | |
| 67 | curr1_input SENSE current (mA) |
| 68 | curr1_min Undercurrent threshold |
| 69 | curr1_max Overcurrent threshold |
| 70 | curr1_lowest Lowest measured current |
| 71 | curr1_highest Highest measured current |
| 72 | curr1_reset_history Write 1 to reset curr1 history |
| 73 | curr1_min_alarm Undercurrent alarm |
| 74 | curr1_max_alarm Overcurrent alarm |
| 75 | |
| 76 | power1_input Power (in uW). Power is calculated based on SENSE+/VDD |
| 77 | voltage or ADIN voltage depending on chip configuration. |
| 78 | power1_min Low lower threshold |
| 79 | power1_max High power threshold |
| 80 | power1_input_lowest Historical minimum power use |
| 81 | power1_input_highest Historical maximum power use |
| 82 | power1_reset_history Write 1 to reset power1 history |
| 83 | power1_min_alarm Low power alarm |
| 84 | power1_max_alarm High power alarm |