iio/adc/ad4000.c

315 	 * In 4-wire mode, the CNV line is held high for the entire conversion  in ad4000_convert_and_acquire()
316 	 * and acquisition process. In other modes, the CNV GPIO is optional  in ad4000_convert_and_acquire()
317 	 * and, if provided, replaces controller CS. If CNV GPIO is not defined  in ad4000_convert_and_acquire()
474  * connected to MOSI or to VIO and ADC CNV pin is connected either to a SPI
476  * AD4000 series of devices initiate conversions on the rising edge of CNV pin.
478  * If the CNV pin is connected to an SPI controller CS line (which is by default
484  * preparatory transfer to pulse the CS/CNV line.
510  * ADC SDI pin and a GPIO is connected to ADC CNV pin.
511  * The GPIO connected to ADC CNV pin is set outside of the SPI transfer.
520 	 * Dummy transfer to cause enough delay between CNV going high and SDI  in ad4000_prepare_4wire_mode_message()
575 	st->cnv_gpio = devm_gpiod_get_optional(dev, "cnv", GPIOD_OUT_HIGH);  in ad4000_probe()
578 				     "Failed to get CNV GPIO");  in ad4000_probe()