| Supported chips: |
| * Dialog Semiconductors DA9055 PMIC |
| Prefix: 'da9055' |
| Datasheet: Datasheet is not publicly available. |
| |
| Authors: David Dajun Chen <dchen@diasemi.com> |
| |
| Description |
| ----------- |
| |
| The DA9055 provides an Analogue to Digital Converter (ADC) with 10 bits |
| resolution and track and hold circuitry combined with an analogue input |
| multiplexer. The analogue input multiplexer will allow conversion of up to 5 |
| different inputs. The track and hold circuit ensures stable input voltages at |
| the input of the ADC during the conversion. |
| |
| The ADC is used to measure the following inputs: |
| Channel 0: VDDOUT - measurement of the system voltage |
| Channel 1: ADC_IN1 - high impedance input (0 - 2.5V) |
| Channel 2: ADC_IN2 - high impedance input (0 - 2.5V) |
| Channel 3: ADC_IN3 - high impedance input (0 - 2.5V) |
| Channel 4: Internal Tjunc. - sense (internal temp. sensor) |
| |
| By using sysfs attributes we can measure the system voltage VDDOUT, |
| chip junction temperature and auxiliary channels voltages. |
| |
| Voltage Monitoring |
| ------------------ |
| |
| Voltages are sampled in a AUTO mode it can be manually sampled too and results |
| are stored in a 10 bit ADC. |
| |
| The system voltage is calculated as: |
| Milli volt = ((ADC value * 1000) / 85) + 2500 |
| |
| The voltages on ADC channels 1, 2 and 3 are calculated as: |
| Milli volt = (ADC value * 1000) / 102 |
| |
| Temperature Monitoring |
| ---------------------- |
| |
| Temperatures are sampled by a 10 bit ADC. Junction temperatures |
| are monitored by the ADC channels. |
| |
| The junction temperature is calculated: |
| Degrees celsius = -0.4084 * (ADC_RES - T_OFFSET) + 307.6332 |
| The junction temperature attribute is supported by the driver. |
