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Based on kernel version 3.13. Page generated on 2014-01-20 22:03 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.
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