STM32_ADC_CH_MAX
struct stm32_adc_diff_channel diff[STM32_ADC_CH_MAX];
u32 smp = 0, smps[STM32_ADC_CH_MAX], chans[STM32_ADC_CH_MAX];
char chan_name[STM32_ADC_CH_MAX][STM32_ADC_CH_SZ];
.max_channels = STM32_ADC_CH_MAX,