diff options
Diffstat (limited to 'Documentation/hwmon/da9052')
| -rw-r--r-- | Documentation/hwmon/da9052 | 41 |
1 files changed, 29 insertions, 12 deletions
diff --git a/Documentation/hwmon/da9052 b/Documentation/hwmon/da9052 index 5bc51346b689..c1c0f1f08904 100644 --- a/Documentation/hwmon/da9052 +++ b/Documentation/hwmon/da9052 @@ -1,6 +1,12 @@ +Kernel driver da9052 +==================== + Supported chips: + * Dialog Semiconductors DA9052-BC and DA9053-AA/Bx PMICs + Prefix: 'da9052' + Datasheet: Datasheet is not publicly available. Authors: David Dajun Chen <dchen@diasemi.com> @@ -15,17 +21,20 @@ 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: ICH - internal battery charger current measurement -Channel 2: TBAT - output from the battery NTC -Channel 3: VBAT - measurement of the battery voltage -Channel 4: ADC_IN4 - high impedance input (0 - 2.5V) -Channel 5: ADC_IN5 - high impedance input (0 - 2.5V) -Channel 6: ADC_IN6 - high impedance input (0 - 2.5V) -Channel 7: XY - TSI interface to measure the X and Y voltage of the touch - screen resistive potentiometers -Channel 8: Internal Tjunc. - sense (internal temp. sensor) -Channel 9: VBBAT - measurement of the backup battery voltage + +========= =================================================================== +Channel 0 VDDOUT - measurement of the system voltage +Channel 1 ICH - internal battery charger current measurement +Channel 2 TBAT - output from the battery NTC +Channel 3 VBAT - measurement of the battery voltage +Channel 4 ADC_IN4 - high impedance input (0 - 2.5V) +Channel 5 ADC_IN5 - high impedance input (0 - 2.5V) +Channel 6 ADC_IN6 - high impedance input (0 - 2.5V) +Channel 7 XY - TSI interface to measure the X and Y voltage of the touch + screen resistive potentiometers +Channel 8 Internal Tjunc. - sense (internal temp. sensor) +Channel 9 VBBAT - measurement of the backup battery voltage +========= =================================================================== By using sysfs attributes we can measure the system voltage VDDOUT, the battery charging current ICH, battery temperature TBAT, battery junction temperature @@ -37,12 +46,15 @@ Voltage Monitoring Voltages are sampled by a 10 bit ADC. The battery voltage is calculated as: + Milli volt = ((ADC value * 1000) / 512) + 2500 The backup battery voltage is calculated as: + Milli volt = (ADC value * 2500) / 512; The voltages on ADC channels 4, 5 and 6 are calculated as: + Milli volt = (ADC value * 2500) / 1023 Temperature Monitoring @@ -52,10 +64,15 @@ Temperatures are sampled by a 10 bit ADC. Junction and battery temperatures are monitored by the ADC channels. The junction temperature is calculated: + Degrees celsius = 1.708 * (TJUNC_RES - T_OFFSET) - 108.8 + The junction temperature attribute is supported by the driver. The battery temperature is calculated: - Degree Celsius = 1 / (t1 + 1/298)- 273 + + Degree Celsius = 1 / (t1 + 1/298) - 273 + where t1 = (1/B)* ln(( ADCval * 2.5)/(R25*ITBAT*255)) + Default values of R25, B, ITBAT are 10e3, 3380 and 50e-6 respectively. |