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review.shift-gmbh.com / SHIFTPHONES / mainline / linux / 1e34064b60552616b2767d22f2e6f440ced09acb / . / Documentation / hwmon / da9052.rst
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Mauro Carvalho Chehab08fae072019-04-17 06:46:24 -0300[diff] [blame]1Kernel driver da9052
2====================
3
Ashish Jangame41f6432012-03-17 15:34:41 +0530[diff] [blame]4Supported chips:
Mauro Carvalho Chehab08fae072019-04-17 06:46:24 -0300[diff] [blame]5
Ashish Jangame41f6432012-03-17 15:34:41 +0530[diff] [blame]6 * Dialog Semiconductors DA9052-BC and DA9053-AA/Bx PMICs
Mauro Carvalho Chehab08fae072019-04-17 06:46:24 -0300[diff] [blame]7
Ashish Jangame41f6432012-03-17 15:34:41 +0530[diff] [blame]8 Prefix: 'da9052'
Mauro Carvalho Chehab08fae072019-04-17 06:46:24 -0300[diff] [blame]9
Ashish Jangame41f6432012-03-17 15:34:41 +0530[diff] [blame]10 Datasheet: Datasheet is not publicly available.
11
12Authors: David Dajun Chen <dchen@diasemi.com>
13
14Description
15-----------
16
17The DA9052/53 provides an Analogue to Digital Converter (ADC) with 10 bits
18resolution and track and hold circuitry combined with an analogue input
19multiplexer. The analogue input multiplexer will allow conversion of up to 10
20different inputs. The track and hold circuit ensures stable input voltages at
21the input of the ADC during the conversion.
22
23The ADC is used to measure the following inputs:
Mauro Carvalho Chehab08fae072019-04-17 06:46:24 -0300[diff] [blame]24
25========= ===================================================================
26Channel 0 VDDOUT - measurement of the system voltage
27Channel 1 ICH - internal battery charger current measurement
28Channel 2 TBAT - output from the battery NTC
29Channel 3 VBAT - measurement of the battery voltage
30Channel 4 ADC_IN4 - high impedance input (0 - 2.5V)
31Channel 5 ADC_IN5 - high impedance input (0 - 2.5V)
32Channel 6 ADC_IN6 - high impedance input (0 - 2.5V)
33Channel 7 XY - TSI interface to measure the X and Y voltage of the touch
34 screen resistive potentiometers
35Channel 8 Internal Tjunc. - sense (internal temp. sensor)
36Channel 9 VBBAT - measurement of the backup battery voltage
37========= ===================================================================
Ashish Jangame41f6432012-03-17 15:34:41 +0530[diff] [blame]38
39By using sysfs attributes we can measure the system voltage VDDOUT, the battery
40charging current ICH, battery temperature TBAT, battery junction temperature
41TJUNC, battery voltage VBAT and the back up battery voltage VBBAT.
42
43Voltage Monitoring
44------------------
45
46Voltages are sampled by a 10 bit ADC.
47
48The battery voltage is calculated as:
Mauro Carvalho Chehab08fae072019-04-17 06:46:24 -0300[diff] [blame]49
Ashish Jangame41f6432012-03-17 15:34:41 +0530[diff] [blame]50 Milli volt = ((ADC value * 1000) / 512) + 2500
51
52The backup battery voltage is calculated as:
Mauro Carvalho Chehab08fae072019-04-17 06:46:24 -0300[diff] [blame]53
Ashish Jangame41f6432012-03-17 15:34:41 +0530[diff] [blame]54 Milli volt = (ADC value * 2500) / 512;
55
56The voltages on ADC channels 4, 5 and 6 are calculated as:
Mauro Carvalho Chehab08fae072019-04-17 06:46:24 -0300[diff] [blame]57
Ashish Jangame41f6432012-03-17 15:34:41 +0530[diff] [blame]58 Milli volt = (ADC value * 2500) / 1023
59
60Temperature Monitoring
61----------------------
62
63Temperatures are sampled by a 10 bit ADC. Junction and battery temperatures
64are monitored by the ADC channels.
65
66The junction temperature is calculated:
Mauro Carvalho Chehab08fae072019-04-17 06:46:24 -0300[diff] [blame]67
Ashish Jangame41f6432012-03-17 15:34:41 +0530[diff] [blame]68 Degrees celsius = 1.708 * (TJUNC_RES - T_OFFSET) - 108.8
Mauro Carvalho Chehab08fae072019-04-17 06:46:24 -0300[diff] [blame]69
Ashish Jangame41f6432012-03-17 15:34:41 +0530[diff] [blame]70The junction temperature attribute is supported by the driver.
71
72The battery temperature is calculated:
Mauro Carvalho Chehab08fae072019-04-17 06:46:24 -0300[diff] [blame]73
74 Degree Celsius = 1 / (t1 + 1/298) - 273
75
Ashish Jangame41f6432012-03-17 15:34:41 +0530[diff] [blame]76where t1 = (1/B)* ln(( ADCval * 2.5)/(R25*ITBAT*255))
Mauro Carvalho Chehab08fae072019-04-17 06:46:24 -0300[diff] [blame]77
Ashish Jangame41f6432012-03-17 15:34:41 +0530[diff] [blame]78Default values of R25, B, ITBAT are 10e3, 3380 and 50e-6 respectively.