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- 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.
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