[PATCH v2 07/12] iio: dac: ad5686: add ldac gpio

From: Rodrigo Alencar via B4 Relay

Date: Tue Jun 09 2026 - 06:28:23 EST


From: Rodrigo Alencar <rodrigo.alencar@xxxxxxxxxx>

If wired LDAC, should be held low when unused (pin is active-low), which
allows for synchronous DAC updates. This will be used to update all the
channels at the same time when adding buffer support.

Signed-off-by: Rodrigo Alencar <rodrigo.alencar@xxxxxxxxxx>
---
drivers/iio/dac/ad5686.c | 6 ++++++
drivers/iio/dac/ad5686.h | 3 +++
2 files changed, 9 insertions(+)

diff --git a/drivers/iio/dac/ad5686.c b/drivers/iio/dac/ad5686.c
index 700798b80f04..db37c3e50389 100644
--- a/drivers/iio/dac/ad5686.c
+++ b/drivers/iio/dac/ad5686.c
@@ -12,6 +12,7 @@
#include <linux/dev_printk.h>
#include <linux/errno.h>
#include <linux/export.h>
+#include <linux/gpio/consumer.h>
#include <linux/kstrtox.h>
#include <linux/module.h>
#include <linux/regulator/consumer.h>
@@ -513,6 +514,11 @@ int ad5686_probe(struct device *dev,
return dev_err_probe(dev, PTR_ERR(rstc),
"Failed to get reset control\n");

+ st->ldac_gpio = devm_gpiod_get_optional(dev, "ldac", GPIOD_OUT_HIGH);
+ if (IS_ERR(st->ldac_gpio))
+ return dev_err_probe(dev, PTR_ERR(st->ldac_gpio),
+ "Failed to get LDAC GPIO\n");
+
fsleep(5); /* power-up time */
reset_control_assert(rstc);
fsleep(1); /* reset pulse: comfortably bigger than the spec */
diff --git a/drivers/iio/dac/ad5686.h b/drivers/iio/dac/ad5686.h
index a06fe7d89305..f3110410d89b 100644
--- a/drivers/iio/dac/ad5686.h
+++ b/drivers/iio/dac/ad5686.h
@@ -60,6 +60,7 @@ enum ad5686_regmap_type {
AD5686_REGMAP,
};

+struct gpio_desc;
struct ad5686_state;

/**
@@ -119,6 +120,7 @@ extern const struct ad5686_chip_info ad5679r_chip_info;
* @dev: device instance
* @chip_info: chip model specific constants, available modes etc
* @ops: bus specific operations
+ * @ldac_gpio: LDAC pin GPIO descriptor
* @vref_mv: actual reference voltage used
* @pwr_down_mask: power down mask
* @pwr_down_mode: current power down mode
@@ -131,6 +133,7 @@ struct ad5686_state {
struct device *dev;
const struct ad5686_chip_info *chip_info;
const struct ad5686_bus_ops *ops;
+ struct gpio_desc *ldac_gpio;
unsigned short vref_mv;
unsigned int pwr_down_mask;
unsigned int pwr_down_mode;

--
2.43.0