| 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. |