Cirrus Logic EP93xx ADC driver

1. Overview

The driver is intended to work on both low-end (EP9301, EP9302) devices with 5-channel ADC and high-end (EP9307, EP9312, EP9315) devices with 10-channel touchscreen/ADC module.

2. Channel numbering

Numbering scheme for channels 0..4 is defined in EP9301 and EP9302 datasheets. EP9307, EP9312 and EP9312 have 3 channels more (total 8), but the numbering is not defined. So the last three are numbered randomly, let's say.

Assuming ep93xx_adc is IIO device0, you'd find the following entries under /sys/bus/iio/devices/iio:device0/:

sysfs entry	ball/pin name
in_voltage0_raw	YM
in_voltage1_raw	SXP
in_voltage2_raw	SXM
in_voltage3_raw	SYP
in_voltage4_raw	SYM
in_voltage5_raw	XP
in_voltage6_raw	XM
in_voltage7_raw	YP