[PATCH 2/2] iio: dac: ad3530r: Fix AD3531/AD3531R powerdown mode strings

From: Kim Seer Paller

Date: Tue May 05 2026 - 00:36:14 EST


The AD3531/AD3531R has different output operating modes from the
AD3530/AD3530R. According to the AD3531/AD3531R datasheet, the
powerdown modes are:
01: 500 Ohm output impedance
10: 3.85 kOhm output impedance
11: 16 kOhm output impedance

The driver currently uses the AD3530R modes (1k, 7.7k, 32k) for all
variants, which is incorrect for AD3531/AD3531R.

Add AD3531R-specific powerdown mode strings and assign them to the
AD3531/AD3531R chip variants.

Fixes: 93583174a3df ("iio: dac: ad3530r: Add driver for AD3530R and AD3531R")
Signed-off-by: Kim Seer Paller <kimseer.paller@xxxxxxxxxx>
---
drivers/iio/dac/ad3530r.c | 54 +++++++++++++++++++++++++++++++++++------------
1 file changed, 40 insertions(+), 14 deletions(-)

diff --git a/drivers/iio/dac/ad3530r.c b/drivers/iio/dac/ad3530r.c
index b97b46090d80..d9db3226ecd6 100644
--- a/drivers/iio/dac/ad3530r.c
+++ b/drivers/iio/dac/ad3530r.c
@@ -105,6 +105,12 @@ static const char * const ad3530r_powerdown_modes[] = {
"32kohm_to_gnd",
};

+static const char * const ad3531r_powerdown_modes[] = {
+ "500ohm_to_gnd",
+ "3.85kohm_to_gnd",
+ "16kohm_to_gnd",
+};
+
static int ad3530r_get_powerdown_mode(struct iio_dev *indio_dev,
const struct iio_chan_spec *chan)
{
@@ -133,6 +139,13 @@ static const struct iio_enum ad3530r_powerdown_mode_enum = {
.set = ad3530r_set_powerdown_mode,
};

+static const struct iio_enum ad3531r_powerdown_mode_enum = {
+ .items = ad3531r_powerdown_modes,
+ .num_items = ARRAY_SIZE(ad3531r_powerdown_modes),
+ .get = ad3530r_get_powerdown_mode,
+ .set = ad3530r_set_powerdown_mode,
+};
+
static ssize_t ad3530r_get_dac_powerdown(struct iio_dev *indio_dev,
uintptr_t private,
const struct iio_chan_spec *chan,
@@ -276,7 +289,20 @@ static const struct iio_chan_spec_ext_info ad3530r_ext_info[] = {
{ }
};

-#define AD3530R_CHAN(_chan) \
+static const struct iio_chan_spec_ext_info ad3531r_ext_info[] = {
+ {
+ .name = "powerdown",
+ .shared = IIO_SEPARATE,
+ .read = ad3530r_get_dac_powerdown,
+ .write = ad3530r_set_dac_powerdown,
+ },
+ IIO_ENUM("powerdown_mode", IIO_SEPARATE, &ad3531r_powerdown_mode_enum),
+ IIO_ENUM_AVAILABLE("powerdown_mode", IIO_SHARED_BY_TYPE,
+ &ad3531r_powerdown_mode_enum),
+ { }
+};
+
+#define AD3530R_CHAN(_chan, _ext_info) \
{ \
.type = IIO_VOLTAGE, \
.indexed = 1, \
@@ -284,25 +310,25 @@ static const struct iio_chan_spec_ext_info ad3530r_ext_info[] = {
.output = 1, \
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
BIT(IIO_CHAN_INFO_SCALE), \
- .ext_info = ad3530r_ext_info, \
+ .ext_info = _ext_info, \
}

static const struct iio_chan_spec ad3530r_channels[] = {
- AD3530R_CHAN(0),
- AD3530R_CHAN(1),
- AD3530R_CHAN(2),
- AD3530R_CHAN(3),
- AD3530R_CHAN(4),
- AD3530R_CHAN(5),
- AD3530R_CHAN(6),
- AD3530R_CHAN(7),
+ AD3530R_CHAN(0, ad3530r_ext_info),
+ AD3530R_CHAN(1, ad3530r_ext_info),
+ AD3530R_CHAN(2, ad3530r_ext_info),
+ AD3530R_CHAN(3, ad3530r_ext_info),
+ AD3530R_CHAN(4, ad3530r_ext_info),
+ AD3530R_CHAN(5, ad3530r_ext_info),
+ AD3530R_CHAN(6, ad3530r_ext_info),
+ AD3530R_CHAN(7, ad3530r_ext_info),
};

static const struct iio_chan_spec ad3531r_channels[] = {
- AD3530R_CHAN(0),
- AD3530R_CHAN(1),
- AD3530R_CHAN(2),
- AD3530R_CHAN(3),
+ AD3530R_CHAN(0, ad3531r_ext_info),
+ AD3530R_CHAN(1, ad3531r_ext_info),
+ AD3530R_CHAN(2, ad3531r_ext_info),
+ AD3530R_CHAN(3, ad3531r_ext_info),
};

static const struct ad3530r_chip_info ad3530_chip = {

--
2.34.1