Hi All,
I work on am437x and use Linux 3.12 that from SDK 7.0, there is not adc1 driver.
Referred to tsc_adc driver, I am writing adc1 driver these days. but I am in a trouble now: the value that I read from ADC1_FIFO1DATA is incorrect!
In our design, the reference voltage input of ADC1 is 1.8V. Here are my steps in driver:
1) Configure STEPCONFIG and STEPDELAY registers
2) Enable ADC1 by setting ADC1_CTRL register
3) Enable step by setting ADC1_STEPEN register (start convert)
4) Wait for FIFO threshold interrupt by reading ADC1_IRQSTS_RAW register and check the FIFO1_THR bit
5) Read adc data from the ADCDATA field of ADC1_FIFO1DATA register
6) Clear the event by setting ADC1_IRQSTS.
The adc data is incorrect. for example, even I connect the ADC1_AIN0 terminal to the ground, the adc data should be 0 but I get the 166. And I put 1.8V to this terminal, the adc data should be 4096 but I get the 1836.
It is very strange. Can anyone help this?
Thanks!
Jakebo
