On 1/7/25 9:27 AM, Jonathan Santos wrote: > The synchronization method using GPIO requires the generated pulse to be > truly synchronous with the base MCLK signal. When it is not possible to > do that in hardware, the datasheet recommends using synchronization over > SPI, where the generated pulse is already synchronous with MCLK. This > requires the SYNC_OUT pin to be connected to SYNC_IN pin. > > Add the option to handle device synchronization over SPI. > > Signed-off-by: Jonathan Santos <Jonathan.Santos@xxxxxxxxxx> > --- ... > static int ad7768_gpio_direction_input(struct gpio_chip *chip, unsigned int offset) > @@ -697,11 +708,21 @@ static int ad7768_setup(struct ad7768_state *st) > if (ret) > return ret; > > - st->gpio_sync_in = devm_gpiod_get(&st->spi->dev, "adi,sync-in", > - GPIOD_OUT_LOW); > + st->gpio_sync_in = devm_gpiod_get_optional(&st->spi->dev, "adi,sync-in", > + GPIOD_OUT_LOW); > if (IS_ERR(st->gpio_sync_in)) > return PTR_ERR(st->gpio_sync_in); > > + if (device_property_present(&st->spi->dev, "adi,sync-in-spi")) > + st->en_spi_sync = true; > + > + /* > + * GPIO and SPI Synchronization are mutually exclusive. > + * Return error if both are enabled Should it also be an error if we have neither? Otherwise it sounds like decimation won't work correctly since there is a comment that says we have to toggle this after updating the decimation rate register. > + */ > + if (st->gpio_sync_in && st->en_spi_sync) > + return -EINVAL; A dev_err_probe() message would be helpful here when creating a new DT and bringing up a new system since it is easy to forget a property or make a typo that could lead to this error. > + > ret = ad7768_gpio_init(st); > if (ret < 0) > return ret;
