projects / linux-block.git / blame
| Commit | Line | Data |
|---|---|---|
| 6700ce03 GR |
1 | Kernel driver ltc2945 |
| 2 | ===================== | |
| 3 | ||
| 4 | Supported chips: | |
| b04f2f7d | 5 | |
| 6700ce03 | 6 | * Linear Technology LTC2945 |
| b04f2f7d | 7 | |
| 6700ce03 | 8 | Prefix: 'ltc2945' |
| b04f2f7d | 9 | |
| 6700ce03 | 10 | Addresses scanned: - |
| b04f2f7d | 11 | |
| 6700ce03 | 12 | Datasheet: |
| b04f2f7d | 13 | |
| f6a496a5 | 14 | https://www.analog.com/media/en/technical-documentation/data-sheets/2945fb.pdf |
| 6700ce03 GR |
15 | |
| 16 | Author: Guenter Roeck <linux@roeck-us.net> | |
| 17 | ||
| 18 | ||
| 19 | Description | |
| 20 | ----------- | |
| 21 | ||
| 22 | The LTC2945 is a rail-to-rail system monitor that measures current, voltage, | |
| 23 | and power consumption. | |
| 24 | ||
| 25 | ||
| 26 | Usage Notes | |
| 27 | ----------- | |
| 28 | ||
| 29 | This driver does not probe for LTC2945 devices, since there is no register | |
| 30 | which can be safely used to identify the chip. You will have to instantiate | |
| 31 | the devices explicitly. | |
| 32 | ||
| 33 | Example: the following will load the driver for an LTC2945 at address 0x10 | |
| b04f2f7d MCC |
34 | on I2C bus #1:: |
| 35 | ||
| 36 | $ modprobe ltc2945 | |
| 37 | $ echo ltc2945 0x10 > /sys/bus/i2c/devices/i2c-1/new_device | |
| 6700ce03 GR |
38 | |
| 39 | ||
| 40 | Sysfs entries | |
| 41 | ------------- | |
| 42 | ||
| 43 | Voltage readings provided by this driver are reported as obtained from the ADC | |
| 44 | registers. If a set of voltage divider resistors is installed, calculate the | |
| 45 | real voltage by multiplying the reported value with (R1+R2)/R2, where R1 is the | |
| 46 | value of the divider resistor against the measured voltage and R2 is the value | |
| 47 | of the divider resistor against Ground. | |
| 48 | ||
| 49 | Current reading provided by this driver is reported as obtained from the ADC | |
| 50 | Current Sense register. The reported value assumes that a 1 mOhm sense resistor | |
| 51 | is installed. If a different sense resistor is installed, calculate the real | |
| 52 | current by dividing the reported value by the sense resistor value in mOhm. | |
| 53 | ||
| b04f2f7d | 54 | ======================= ======================================================== |
| 6700ce03 GR |
55 | in1_input VIN voltage (mV). Voltage is measured either at |
| 56 | SENSE+ or VDD pin depending on chip configuration. | |
| 57 | in1_min Undervoltage threshold | |
| 58 | in1_max Overvoltage threshold | |
| 59 | in1_lowest Lowest measured voltage | |
| 60 | in1_highest Highest measured voltage | |
| 61 | in1_reset_history Write 1 to reset in1 history | |
| 62 | in1_min_alarm Undervoltage alarm | |
| 63 | in1_max_alarm Overvoltage alarm | |
| 64 | ||
| 65 | in2_input ADIN voltage (mV) | |
| 66 | in2_min Undervoltage threshold | |
| 67 | in2_max Overvoltage threshold | |
| 68 | in2_lowest Lowest measured voltage | |
| 69 | in2_highest Highest measured voltage | |
| 70 | in2_reset_history Write 1 to reset in2 history | |
| 71 | in2_min_alarm Undervoltage alarm | |
| 72 | in2_max_alarm Overvoltage alarm | |
| 73 | ||
| 74 | curr1_input SENSE current (mA) | |
| 75 | curr1_min Undercurrent threshold | |
| 76 | curr1_max Overcurrent threshold | |
| 77 | curr1_lowest Lowest measured current | |
| 78 | curr1_highest Highest measured current | |
| 79 | curr1_reset_history Write 1 to reset curr1 history | |
| 80 | curr1_min_alarm Undercurrent alarm | |
| 81 | curr1_max_alarm Overcurrent alarm | |
| 82 | ||
| 83 | power1_input Power (in uW). Power is calculated based on SENSE+/VDD | |
| 84 | voltage or ADIN voltage depending on chip configuration. | |
| 85 | power1_min Low lower threshold | |
| 86 | power1_max High power threshold | |
| 87 | power1_input_lowest Historical minimum power use | |
| 88 | power1_input_highest Historical maximum power use | |
| 89 | power1_reset_history Write 1 to reset power1 history | |
| 90 | power1_min_alarm Low power alarm | |
| 91 | power1_max_alarm High power alarm | |
| b04f2f7d | 92 | ======================= ======================================================== |