Based on kernel version 4.16.1. Page generated on 2018-04-09 11:53 EST.
1 Supported chips: 2 * Dialog Semiconductors DA9055 PMIC 3 Prefix: 'da9055' 4 Datasheet: Datasheet is not publicly available. 5 6 Authors: David Dajun Chen <dchen@diasemi.com> 7 8 Description 9 ----------- 10 11 The DA9055 provides an Analogue to Digital Converter (ADC) with 10 bits 12 resolution and track and hold circuitry combined with an analogue input 13 multiplexer. The analogue input multiplexer will allow conversion of up to 5 14 different inputs. The track and hold circuit ensures stable input voltages at 15 the input of the ADC during the conversion. 16 17 The ADC is used to measure the following inputs: 18 Channel 0: VDDOUT - measurement of the system voltage 19 Channel 1: ADC_IN1 - high impedance input (0 - 2.5V) 20 Channel 2: ADC_IN2 - high impedance input (0 - 2.5V) 21 Channel 3: ADC_IN3 - high impedance input (0 - 2.5V) 22 Channel 4: Internal Tjunc. - sense (internal temp. sensor) 23 24 By using sysfs attributes we can measure the system voltage VDDOUT, 25 chip junction temperature and auxiliary channels voltages. 26 27 Voltage Monitoring 28 ------------------ 29 30 Voltages are sampled in a AUTO mode it can be manually sampled too and results 31 are stored in a 10 bit ADC. 32 33 The system voltage is calculated as: 34 Milli volt = ((ADC value * 1000) / 85) + 2500 35 36 The voltages on ADC channels 1, 2 and 3 are calculated as: 37 Milli volt = (ADC value * 1000) / 102 38 39 Temperature Monitoring 40 ---------------------- 41 42 Temperatures are sampled by a 10 bit ADC. Junction temperatures 43 are monitored by the ADC channels. 44 45 The junction temperature is calculated: 46 Degrees celsius = -0.4084 * (ADC_RES - T_OFFSET) + 307.6332 47 The junction temperature attribute is supported by the driver.