iio: dac: ad5791: Add reset, clr and ldac gpios

The ad7591 has reset, clr and ldac gpios, that might need to be
controlled. Add them to the driver.

Signed-off-by: Axel Haslam <ahaslam@baylibre.com>

drivers/iio/dac/ad5791.c

@@ -85,6 +85,9 @@ struct ad5791_state {
 	struct spi_device		*spi;
 	struct regulator		*reg_vdd;
 	struct regulator		*reg_vss;
+	struct gpio_desc		*gpio_reset;
+	struct gpio_desc		*gpio_clear;
+	struct gpio_desc		*gpio_ldac;
 	const struct ad5791_chip_info	*chip_info;
 	unsigned short			vref_mv;
 	unsigned int			vref_neg_mv;
@@ -377,6 +380,21 @@ static int ad5791_probe(struct spi_device *spi)
 		neg_voltage_uv = ret;
 	}
 
+	st->gpio_reset = devm_gpiod_get_optional(&spi->dev, "reset",
+						  GPIOD_OUT_LOW);
+	if (IS_ERR(st->gpio_reset))
+		return PTR_ERR(st->gpio_reset);
+
+	st->gpio_clear = devm_gpiod_get_optional(&spi->dev, "clear",
+						  GPIOD_OUT_LOW);
+	if (IS_ERR(st->gpio_clear))
+		return PTR_ERR(st->gpio_clear);
+
+	st->gpio_ldac = devm_gpiod_get_optional(&spi->dev, "ldac",
+						  GPIOD_OUT_LOW);
+	if (IS_ERR(st->gpio_ldac))
+		return PTR_ERR(st->gpio_ldac);
+
 	st->pwr_down = true;
 	st->spi = spi;