MCP3422_CHANNEL_MASK
if (req_channel != FIELD_GET(MCP3422_CHANNEL_MASK, adc->config)) {
FIELD_MODIFY(MCP3422_CHANNEL_MASK, &config, req_channel);
FIELD_MODIFY(MCP3422_CHANNEL_MASK, &config, req_channel);
FIELD_MODIFY(MCP3422_CHANNEL_MASK, &config, req_channel);
FIELD_PREP(MCP3422_CHANNEL_MASK, 0) |