[PATCH v6 0/6] iio: dac: ad5504: bindings, cleanups, locking, and scale fixes

[PATCH v6 0/6] iio: dac: ad5504: bindings, cleanups, locking, and scale fixes

[Taha Ed-Dafili]

Jonathan Cameron applied patches 2 (sort headers alphabetically) and 4
(introduce local dev pointer) from v3 directly to iio/testing. This
series rebases on top of that state and does not re-send those
patches.

This v6 series addresses one remaining item from the v5 review by
Andy Shevchenko:

* In ad5504_write_dac_powerdown(), move guard(mutex) to after
  kstrtobool() since input parsing does not touch shared state and
  does not need to be under the lock (Andy)

Testing:
No functional change from v5. This only narrows the critical section
in one sysfs write path. Re-verified on ARM64 Raspberry Pi 5 (BCM2712):
powerdown sysfs read/write and powerdown mode switching (20kohm_to_gnd,
three_state) verified on all four channels without errors.

Previous versions:
v5: https://lore.kernel.org/linux-iio/20260821102255.36705-1-0rayn.dev@gmail.com/
v4: https://lore.kernel.org/linux-iio/20260817211118.21833-1-0rayn.dev@gmail.com/
v3: https://lore.kernel.org/linux-iio/20260509142047.30302-1-0rayn.dev@gmail.com/
v2: https://lore.kernel.org/linux-iio/20260310174835.24209-1-0rayn.dev@gmail.com/
v1: https://lore.kernel.org/linux-iio/20260212181955.42724-1-0rayn.dev@gmail.com/

Thank you to Jonathan Cameron, David Lechner, Andy Shevchenko, Nuno Sá,
Krzysztof Kozlowski, Conor Dooley, Uwe Kleine-König, and Joshua Crofts
for the continued reviews.

Taha Ed-Dafili (6):
  dt-bindings: iio: dac: ad5504: add output-range and missing gpios
  iio: dac: ad5504: Align headers with IWYU principle
  iio: dac: ad5504: separate ACPI and DT paths
  iio: dac: ad5504: remove legacy platform data support
  iio: dac: ad5504: introduce local lock to protect state and spi
    transfers
  iio: dac: ad5504: support scale via output-range-microvolt property

 .../bindings/iio/dac/adi,ad5504.yaml          | 39 ++++++++-
 drivers/iio/dac/ad5504.c                      | 82 +++++++++++++++----
 include/linux/iio/dac/ad5504.h                | 15 ----
 3 files changed, 103 insertions(+), 33 deletions(-)
 delete mode 100644 include/linux/iio/dac/ad5504.h

-- 
2.55.0

[PATCH v6 1/6] dt-bindings: iio: dac: ad5504: add output-range and missing gpios

[Taha Ed-Dafili]

The AD5504 output range (0-30V or 0-60V) is determined by the R_SEL pin.

Use standard output-range-microvolt and range-sel-gpios properties to
describe the hardware configuration of the R_SEL pin. Ensure mutual
exclusivity using the not/required logic. Additionally, add missing
vlogic-supply, clr-gpios, ldac-gpios and datasheet links, and provide
a complete usage example.

Signed-off-by: Taha Ed-Dafili <0rayn.dev@gmail.com>
Acked-by: Conor Dooley <conor.dooley@microchip.com>
---
 .../bindings/iio/dac/adi,ad5504.yaml          | 39 ++++++++++++++++++-
 1 file changed, 38 insertions(+), 1 deletion(-)

diff --git a/Documentation/devicetree/bindings/iio/dac/adi,ad5504.yaml b/Documentation/devicetree/bindings/iio/dac/adi,ad5504.yaml
index 9c2c038683b4..e0123dceaa33 100644
--- a/Documentation/devicetree/bindings/iio/dac/adi,ad5504.yaml
+++ b/Documentation/devicetree/bindings/iio/dac/adi,ad5504.yaml
@@ -10,8 +10,10 @@ maintainers:
   - Lars-Peter Clausen <lars@metafoo.de>
   - Jonathan Cameron <jic23@kernel.org>
 
-description:
+description: |
   High voltage (up to 60V) DACs with temperature sensor alarm function
+  https://www.analog.com/media/en/technical-documentation/data-sheets/ad5504.pdf
+  https://www.analog.com/media/en/technical-documentation/data-sheets/ad5501.pdf
 
 properties:
   compatible:
@@ -27,6 +29,29 @@ properties:
     maxItems: 1
 
   vcc-supply: true
+  vlogic-supply: true
+
+  output-range-microvolt:
+    description: |
+      Specify the channel output full scale range. The R_SEL pin
+      determines if the range is 0-30V or 0-60V.
+    items:
+      - const: 0
+      - enum: [30000000, 60000000]
+    default: [0, 60000000]
+
+  range-sel-gpios:
+    description:
+      GPIO connected to the R_SEL pin to select the output voltage range.
+    maxItems: 1
+
+  clr-gpios:
+    description: GPIO that controls the /CLR pin (active low).
+    maxItems: 1
+
+  ldac-gpios:
+    description: GPIO that controls the /LDAC pin (active low).
+    maxItems: 1
 
 additionalProperties: false
 
@@ -34,9 +59,17 @@ required:
   - compatible
   - reg
 
+allOf:
+  - not:
+      required:
+        - range-sel-gpios
+        - output-range-microvolt
+
 examples:
   - |
     #include <dt-bindings/interrupt-controller/irq.h>
+    #include <dt-bindings/gpio/gpio.h>
+
     spi {
         #address-cells = <1>;
         #size-cells = <0>;
@@ -45,6 +78,10 @@ examples:
             compatible = "adi,ad5504";
             vcc-supply = <&dac_vcc>;
             interrupts = <55 IRQ_TYPE_EDGE_FALLING>;
+
+            output-range-microvolt = <0 60000000>;
+            clr-gpios = <&gpio 4 GPIO_ACTIVE_LOW>;
+            ldac-gpios = <&gpio 5 GPIO_ACTIVE_LOW>;
         };
     };
 ...
-- 
2.55.0

Re: [PATCH v6 1/6] dt-bindings: iio: dac: ad5504: add output-range and missing gpios

[David Lechner]

On 8/22/26 3:56 AM, Taha Ed-Dafili wrote:
> The AD5504 output range (0-30V or 0-60V) is determined by the R_SEL pin.
> 
> Use standard output-range-microvolt and range-sel-gpios properties to
> describe the hardware configuration of the R_SEL pin. Ensure mutual
> exclusivity using the not/required logic. Additionally, add missing
> vlogic-supply, clr-gpios, ldac-gpios and datasheet links, and provide
> a complete usage example.
> 
> Signed-off-by: Taha Ed-Dafili <0rayn.dev@gmail.com>
> Acked-by: Conor Dooley <conor.dooley@microchip.com>
> ---
>  .../bindings/iio/dac/adi,ad5504.yaml          | 39 ++++++++++++++++++-
>  1 file changed, 38 insertions(+), 1 deletion(-)
> 
> diff --git a/Documentation/devicetree/bindings/iio/dac/adi,ad5504.yaml b/Documentation/devicetree/bindings/iio/dac/adi,ad5504.yaml
> index 9c2c038683b4..e0123dceaa33 100644
> --- a/Documentation/devicetree/bindings/iio/dac/adi,ad5504.yaml
> +++ b/Documentation/devicetree/bindings/iio/dac/adi,ad5504.yaml
> @@ -10,8 +10,10 @@ maintainers:
>    - Lars-Peter Clausen <lars@metafoo.de>
>    - Jonathan Cameron <jic23@kernel.org>
>  
> -description:
> +description: |
>    High voltage (up to 60V) DACs with temperature sensor alarm function
> +  https://www.analog.com/media/en/technical-documentation/data-sheets/ad5504.pdf
> +  https://www.analog.com/media/en/technical-documentation/data-sheets/ad5501.pdf
>  
>  properties:
>    compatible:
> @@ -27,6 +29,29 @@ properties:
>      maxItems: 1
>  
>    vcc-supply: true
> +  vlogic-supply: true
> +
> +  output-range-microvolt:
> +    description: |
> +      Specify the channel output full scale range. The R_SEL pin
> +      determines if the range is 0-30V or 0-60V.
> +    items:
> +      - const: 0
> +      - enum: [30000000, 60000000]
> +    default: [0, 60000000]
> +
> +  range-sel-gpios:
> +    description:
> +      GPIO connected to the R_SEL pin to select the output voltage range.
> +    maxItems: 1
> +
> +  clr-gpios:

This is one that is starting to emerge as a common name, so I would call
it clear-gpios instead to match the same name on chips with a similar
function.

> +    description: GPIO that controls the /CLR pin (active low).
> +    maxItems: 1
> +
> +  ldac-gpios:
> +    description: GPIO that controls the /LDAC pin (active low).
> +    maxItems: 1
>  
>  additionalProperties: false
>  
> @@ -34,9 +59,17 @@ required:
>    - compatible
>    - reg
>  
> +allOf:
> +  - not:
> +      required:
> +        - range-sel-gpios
> +        - output-range-microvolt
> +
>  examples:
>    - |
>      #include <dt-bindings/interrupt-controller/irq.h>
> +    #include <dt-bindings/gpio/gpio.h>
> +
>      spi {
>          #address-cells = <1>;
>          #size-cells = <0>;
> @@ -45,6 +78,10 @@ examples:
>              compatible = "adi,ad5504";
>              vcc-supply = <&dac_vcc>;
>              interrupts = <55 IRQ_TYPE_EDGE_FALLING>;
> +
> +            output-range-microvolt = <0 60000000>;
> +            clr-gpios = <&gpio 4 GPIO_ACTIVE_LOW>;
> +            ldac-gpios = <&gpio 5 GPIO_ACTIVE_LOW>;
>          };
>      };
>  ...

Re: [PATCH v6 1/6] dt-bindings: iio: dac: ad5504: add output-range and missing gpios

[Taha Ed-Dafili]

> This is one that is starting to emerging as a common name, so I would
> call it clear-gpios instead to match the same name on chips with a
> similar function.

Worth noting Nuno asked for the opposite in v2 review, specifically
to match the datasheet's /CLR pin name:

https://lore.kernel.org/linux-iio/a79296dc96215a579c29c5c9eda464f818f050d6.camel@gmail.com/

Let me know which name you'd prefer given that context, and I'll
update it in v7.

Best Regards,
Taha Ed-Dafili

Re: [PATCH v6 1/6] dt-bindings: iio: dac: ad5504: add output-range and missing gpios

[David Lechner]

On 8/22/26 2:36 PM, Taha Ed-Dafili wrote:
>> This is one that is starting to emerging as a common name, so I would
>> call it clear-gpios instead to match the same name on chips with a
>> similar function.
> 
> Worth noting Nuno asked for the opposite in v2 review, specifically
> to match the datasheet's /CLR pin name:

Normally I advocate for matching the pin name too. But there are some common
things like reset-gpios where we try to always use the same name. This clear
input seems to be one of those common things.

> 
> https://lore.kernel.org/linux-iio/a79296dc96215a579c29c5c9eda464f818f050d6.camel@gmail.com/
> 
> Let me know which name you'd prefer given that context, and I'll
> update it in v7.
> 
> Best Regards,
> Taha Ed-Dafili


There is only one binding currently with clr-gpios (adi,ltc2688).

And only one with clear-gpios (adi,ad5791). Plus at least two more coming
soon [1] [2].

In [3], there is a /CLR pin, but we called it reset-gpios because it also
resets the control registers.

I didn't re-check the datasheets on all of these, but hopefully we are being
consistent.

[1]: https://lore.kernel.org/linux-iio/20260820-ad5529r-driver-v9-2-ba62e0b2a816@analog.com/
[2]: https://lore.kernel.org/linux-iio/20260802-dac8163-work-v3-1-3ecc7bc66d0d@gmx.net/
[3]: https://lore.kernel.org/linux-iio/20240714133000.5866-5-kimseer.paller@analog.com/

Re: [PATCH v6 1/6] dt-bindings: iio: dac: ad5504: add output-range and missing gpios

[Jonathan Cameron]

On Sat, 22 Aug 2026 17:37:22 -0500
David Lechner <dlechner@baylibre.com> wrote:

> On 8/22/26 2:36 PM, Taha Ed-Dafili wrote:
> >> This is one that is starting to emerging as a common name, so I would
> >> call it clear-gpios instead to match the same name on chips with a
> >> similar function.  
> > 
> > Worth noting Nuno asked for the opposite in v2 review, specifically
> > to match the datasheet's /CLR pin name:  
> 
> Normally I advocate for matching the pin name too. But there are some common
> things like reset-gpios where we try to always use the same name. This clear
> input seems to be one of those common things.
> 
> > 
> > https://lore.kernel.org/linux-iio/a79296dc96215a579c29c5c9eda464f818f050d6.camel@gmail.com/
> > 
> > Let me know which name you'd prefer given that context, and I'll
> > update it in v7.
> > 
> > Best Regards,
> > Taha Ed-Dafili  
> 
> 
> There is only one binding currently with clr-gpios (adi,ltc2688).

That one is a reset I think. Includes "The control registers are cleared
to default values".  It sort of clears the DAC as the default is 0V
So probably like 3 below.

> 
> And only one with clear-gpios (adi,ad5791). Plus at least two more coming
> soon [1] [2].
ad5701 clr sets it to a user defined value..  If that's left as default it
sets to 0. That does overwrite the dac register (table 9)

ad5529r actually calls it clear on the datasheet. And just sets DAC outputs
to 0 (including the registers)

dac8163 is 0 scale, or mid scale depending on part. Registers written.
> 
> In [3], there is a /CLR pin, but we called it reset-gpios because it also
> resets the control registers.
> 
> I didn't re-check the datasheets on all of these, but hopefully we are being
> consistent.
Other than the one that maybe should have been a reset and isn't :(

They aren't quite the same across parts but close enough perhaps to generalize
the binding with some flexibility in the description.

Jonathan

> 
> [1]: https://lore.kernel.org/linux-iio/20260820-ad5529r-driver-v9-2-ba62e0b2a816@analog.com/
> [2]: https://lore.kernel.org/linux-iio/20260802-dac8163-work-v3-1-3ecc7bc66d0d@gmx.net/
> [3]: https://lore.kernel.org/linux-iio/20240714133000.5866-5-kimseer.paller@analog.com/
> 
> 
> 
> 

[PATCH v6 2/6] iio: dac: ad5504: Align headers with IWYU principle

[Taha Ed-Dafili]

Update the header inclusions to follow the IWYU principle and ensure
they are sorted alphabetically:

- Remove <linux/fs.h>, <linux/slab.h>, and <linux/kernel.h> as they
  are unused. The driver relies on devm_ managed allocations, so slab
  is not required.
- Replace <linux/bitops.h> with <linux/bits.h> as only the BIT() and
  GENMASK() macros are used.
- Add <linux/errno.h> and <linux/types.h> for error codes and data types.
- Add <asm/byteorder.h> for cpu_to_be16().
- Add <linux/array_size.h> for ARRAY_SIZE().
- Add <linux/kstrtox.h> for string to integer conversions.
- Replaced <linux/device.h> with <linux/dev_printk.h>

Signed-off-by: Taha Ed-Dafili <0rayn.dev@gmail.com>
---
 drivers/iio/dac/ad5504.c | 13 ++++++++-----
 1 file changed, 8 insertions(+), 5 deletions(-)

diff --git a/drivers/iio/dac/ad5504.c b/drivers/iio/dac/ad5504.c
index ad1a74678cf2..5c9c66b04154 100644
--- a/drivers/iio/dac/ad5504.c
+++ b/drivers/iio/dac/ad5504.c
@@ -5,22 +5,25 @@
  * Copyright 2011 Analog Devices Inc.
  */
 
-#include <linux/bitops.h>
-#include <linux/device.h>
-#include <linux/fs.h>
+#include <linux/array_size.h>
+#include <linux/bits.h>
+#include <linux/dev_printk.h>
+#include <linux/errno.h>
 #include <linux/interrupt.h>
-#include <linux/kernel.h>
+#include <linux/kstrtox.h>
 #include <linux/module.h>
 #include <linux/regulator/consumer.h>
-#include <linux/slab.h>
 #include <linux/spi/spi.h>
 #include <linux/sysfs.h>
+#include <linux/types.h>
 
 #include <linux/iio/dac/ad5504.h>
 #include <linux/iio/events.h>
 #include <linux/iio/iio.h>
 #include <linux/iio/sysfs.h>
 
+#include <asm/byteorder.h>
+
 #define AD5504_RES_MASK			GENMASK(11, 0)
 #define AD5504_CMD_READ			BIT(15)
 #define AD5504_CMD_WRITE		0
-- 
2.55.0

[PATCH v6 3/6] iio: dac: ad5504: separate ACPI and DT paths

[Taha Ed-Dafili]

The driver relied on a fragile -ENODEV check from the regulator
framework to bypass voltage configuration on ACPI platforms, sharing
the same fallback path as legacy pdata.

Fork probe on is_acpi_device_node() to explicitly handle each path.
On ACPI, skip the regulator and use a fixed 60V default via
AD5504_VREF_ACPI_DEFAULT_mV. The pdata fallback remains for non-ACPI
systems in this commit; it is removed in the next.

Signed-off-by: Taha Ed-Dafili <0rayn.dev@gmail.com>
---
 drivers/iio/dac/ad5504.c | 29 ++++++++++++++++++++---------
 1 file changed, 20 insertions(+), 9 deletions(-)

diff --git a/drivers/iio/dac/ad5504.c b/drivers/iio/dac/ad5504.c
index 5c9c66b04154..6f70c57c7a82 100644
--- a/drivers/iio/dac/ad5504.c
+++ b/drivers/iio/dac/ad5504.c
@@ -5,6 +5,7 @@
  * Copyright 2011 Analog Devices Inc.
  */
 
+#include <linux/acpi.h>
 #include <linux/array_size.h>
 #include <linux/bits.h>
 #include <linux/dev_printk.h>
@@ -12,10 +13,12 @@
 #include <linux/interrupt.h>
 #include <linux/kstrtox.h>
 #include <linux/module.h>
+#include <linux/property.h>
 #include <linux/regulator/consumer.h>
 #include <linux/spi/spi.h>
 #include <linux/sysfs.h>
 #include <linux/types.h>
+#include <linux/units.h>
 
 #include <linux/iio/dac/ad5504.h>
 #include <linux/iio/events.h>
@@ -24,6 +27,10 @@
 
 #include <asm/byteorder.h>
 
+/*
+ * In case of ACPI, we use the 60 V as default voltage reference.
+ */
+#define AD5504_VREF_ACPI_DEFAULT_mV	(60 * MILLI)
 #define AD5504_RES_MASK			GENMASK(11, 0)
 #define AD5504_CMD_READ			BIT(15)
 #define AD5504_CMD_WRITE		0
@@ -285,16 +292,20 @@ static int ad5504_probe(struct spi_device *spi)
 
 	st = iio_priv(indio_dev);
 
-	ret = devm_regulator_get_enable_read_voltage(dev, "vcc");
-	if (ret < 0 && ret != -ENODEV)
-		return ret;
-	if (ret == -ENODEV) {
-		if (pdata->vref_mv)
-			st->vref_mv = pdata->vref_mv;
-		else
-			dev_warn(dev, "reference voltage unspecified\n");
+	if (is_acpi_device_node(dev_fwnode(dev))) {
+		st->vref_mv = AD5504_VREF_ACPI_DEFAULT_mV;
 	} else {
-		st->vref_mv = ret / 1000;
+		ret = devm_regulator_get_enable_read_voltage(dev, "vcc");
+		if (ret < 0 && ret != -ENODEV)
+			return ret;
+		if (ret == -ENODEV) {
+			if (pdata->vref_mv)
+				st->vref_mv = pdata->vref_mv;
+			else
+				dev_warn(dev, "reference voltage unspecified\n");
+		} else {
+			st->vref_mv = ret / 1000;
+		}
 	}
 
 	st->spi = spi;
-- 
2.55.0

[PATCH v6 4/6] iio: dac: ad5504: remove legacy platform data support

[Taha Ed-Dafili]

The AD5504 driver has no in-tree users of its legacy platform data
support. Now that ACPI has its own explicit path, non-ACPI systems can
safely treat the vcc regulator as mandatory.

Drop the ad5504_platform_data structure, remove the fallback logic
from probe, and delete include/linux/iio/dac/ad5504.h.

Signed-off-by: Taha Ed-Dafili <0rayn.dev@gmail.com>
---
 drivers/iio/dac/ad5504.c       | 17 +++++------------
 include/linux/iio/dac/ad5504.h | 15 ---------------
 2 files changed, 5 insertions(+), 27 deletions(-)
 delete mode 100644 include/linux/iio/dac/ad5504.h

diff --git a/drivers/iio/dac/ad5504.c b/drivers/iio/dac/ad5504.c
index 6f70c57c7a82..799726eafdf2 100644
--- a/drivers/iio/dac/ad5504.c
+++ b/drivers/iio/dac/ad5504.c
@@ -20,7 +20,6 @@
 #include <linux/types.h>
 #include <linux/units.h>
 
-#include <linux/iio/dac/ad5504.h>
 #include <linux/iio/events.h>
 #include <linux/iio/iio.h>
 #include <linux/iio/sysfs.h>
@@ -281,7 +280,6 @@ static const struct iio_chan_spec ad5504_channels[] = {
 static int ad5504_probe(struct spi_device *spi)
 {
 	struct device *dev = &spi->dev;
-	const struct ad5504_platform_data *pdata = dev_get_platdata(dev);
 	struct iio_dev *indio_dev;
 	struct ad5504_state *st;
 	int ret;
@@ -296,16 +294,11 @@ static int ad5504_probe(struct spi_device *spi)
 		st->vref_mv = AD5504_VREF_ACPI_DEFAULT_mV;
 	} else {
 		ret = devm_regulator_get_enable_read_voltage(dev, "vcc");
-		if (ret < 0 && ret != -ENODEV)
-			return ret;
-		if (ret == -ENODEV) {
-			if (pdata->vref_mv)
-				st->vref_mv = pdata->vref_mv;
-			else
-				dev_warn(dev, "reference voltage unspecified\n");
-		} else {
-			st->vref_mv = ret / 1000;
-		}
+		if (ret < 0)
+			return dev_err_probe(dev, ret,
+					     "Failed to get vcc regulator\n");
+
+		st->vref_mv = ret / 1000;
 	}
 
 	st->spi = spi;
diff --git a/include/linux/iio/dac/ad5504.h b/include/linux/iio/dac/ad5504.h
deleted file mode 100644
index 9f23c90486ee..000000000000
--- a/include/linux/iio/dac/ad5504.h
+++ /dev/null
@@ -1,15 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0-only */
-/*
- * AD5504 SPI DAC driver
- *
- * Copyright 2011 Analog Devices Inc.
- */
-
-#ifndef SPI_AD5504_H_
-#define SPI_AD5504_H_
-
-struct ad5504_platform_data {
-	u16				vref_mv;
-};
-
-#endif /* SPI_AD5504_H_ */
-- 
2.55.0

[PATCH v6 5/6] iio: dac: ad5504: introduce local lock to protect state and spi transfers

[Taha Ed-Dafili]

The driver lacks locking, exposing concurrent access to the shared DMA
SPI buffers, the non-atomic CTRL+NOOP write sequence in powerdown, and
the pwr_down_mask/pwr_down_mode state variables.

Introduce a mutex via devm_mutex_init() and guard(mutex) at the IIO
callbacks to serialize access. In read_raw() and write_raw(), scope the
lock to IIO_CHAN_INFO_RAW only since IIO_CHAN_INFO_SCALE reads vref_mv
which is immutable after probe.

Signed-off-by: Taha Ed-Dafili <0rayn.dev@gmail.com>
---
 drivers/iio/dac/ad5504.c | 26 ++++++++++++++++++++++++--
 1 file changed, 24 insertions(+), 2 deletions(-)

diff --git a/drivers/iio/dac/ad5504.c b/drivers/iio/dac/ad5504.c
index 799726eafdf2..74679feea385 100644
--- a/drivers/iio/dac/ad5504.c
+++ b/drivers/iio/dac/ad5504.c
@@ -8,11 +8,13 @@
 #include <linux/acpi.h>
 #include <linux/array_size.h>
 #include <linux/bits.h>
+#include <linux/cleanup.h>
 #include <linux/dev_printk.h>
 #include <linux/errno.h>
 #include <linux/interrupt.h>
 #include <linux/kstrtox.h>
 #include <linux/module.h>
+#include <linux/mutex.h>
 #include <linux/property.h>
 #include <linux/regulator/consumer.h>
 #include <linux/spi/spi.h>
@@ -55,10 +57,12 @@
  * @pwr_down_mask:	power down mask
  * @pwr_down_mode:	current power down mode
  * @data:		transfer buffer
+ * @lock:		lock to protect state and spi transfers
  */
 struct ad5504_state {
 	struct spi_device		*spi;
 	struct regulator		*reg;
+	struct mutex			lock;
 	unsigned short			vref_mv;
 	unsigned			pwr_down_mask;
 	unsigned			pwr_down_mode;
@@ -109,7 +113,9 @@ static int ad5504_read_raw(struct iio_dev *indio_dev,
 	int ret;
 
 	switch (m) {
-	case IIO_CHAN_INFO_RAW:
+	case IIO_CHAN_INFO_RAW: {
+		guard(mutex)(&st->lock);
+
 		ret = ad5504_spi_read(st, chan->address);
 		if (ret < 0)
 			return ret;
@@ -117,6 +123,7 @@ static int ad5504_read_raw(struct iio_dev *indio_dev,
 		*val = ret;
 
 		return IIO_VAL_INT;
+	}
 	case IIO_CHAN_INFO_SCALE:
 		*val = st->vref_mv;
 		*val2 = chan->scan_type.realbits;
@@ -134,11 +141,14 @@ static int ad5504_write_raw(struct iio_dev *indio_dev,
 	struct ad5504_state *st = iio_priv(indio_dev);
 
 	switch (mask) {
-	case IIO_CHAN_INFO_RAW:
+	case IIO_CHAN_INFO_RAW: {
+		guard(mutex)(&st->lock);
+
 		if (val >= (1 << chan->scan_type.realbits) || val < 0)
 			return -EINVAL;
 
 		return ad5504_spi_write(st, chan->address, val);
+	}
 	default:
 		return -EINVAL;
 	}
@@ -154,6 +164,8 @@ static int ad5504_get_powerdown_mode(struct iio_dev *indio_dev,
 {
 	struct ad5504_state *st = iio_priv(indio_dev);
 
+	guard(mutex)(&st->lock);
+
 	return st->pwr_down_mode;
 }
 
@@ -162,6 +174,8 @@ static int ad5504_set_powerdown_mode(struct iio_dev *indio_dev,
 {
 	struct ad5504_state *st = iio_priv(indio_dev);
 
+	guard(mutex)(&st->lock);
+
 	st->pwr_down_mode = mode;
 
 	return 0;
@@ -179,6 +193,8 @@ static ssize_t ad5504_read_dac_powerdown(struct iio_dev *indio_dev,
 {
 	struct ad5504_state *st = iio_priv(indio_dev);
 
+	guard(mutex)(&st->lock);
+
 	return sysfs_emit(buf, "%d\n",
 			  !(st->pwr_down_mask & (1 << chan->channel)));
 }
@@ -195,6 +211,8 @@ static ssize_t ad5504_write_dac_powerdown(struct iio_dev *indio_dev,
 	if (ret)
 		return ret;
 
+	guard(mutex)(&st->lock);
+
 	if (pwr_down)
 		st->pwr_down_mask &= ~(1 << chan->channel);
 	else
@@ -290,6 +308,10 @@ static int ad5504_probe(struct spi_device *spi)
 
 	st = iio_priv(indio_dev);
 
+	ret = devm_mutex_init(dev, &st->lock);
+	if (ret)
+		return ret;
+
 	if (is_acpi_device_node(dev_fwnode(dev))) {
 		st->vref_mv = AD5504_VREF_ACPI_DEFAULT_mV;
 	} else {
-- 
2.55.0

[PATCH v6 6/6] iio: dac: ad5504: support scale via output-range-microvolt property

[Taha Ed-Dafili]

The AD5504 output range is set by the R_SEL pin, not the VCC supply.
Add support for 'output-range-microvolt' to set vref_mv directly from
firmware. Use device_property_present() to distinguish absent from
malformed property rather than relying on the ambiguous -EINVAL from
device_property_read_u32_array(). Fall back to the vcc regulator
voltage for old DTs that predate this property.

Signed-off-by: Taha Ed-Dafili <0rayn.dev@gmail.com>
---
 drivers/iio/dac/ad5504.c | 31 +++++++++++++++++++++++++------
 1 file changed, 25 insertions(+), 6 deletions(-)

diff --git a/drivers/iio/dac/ad5504.c b/drivers/iio/dac/ad5504.c
index 74679feea385..d0a3dd4b000d 100644
--- a/drivers/iio/dac/ad5504.c
+++ b/drivers/iio/dac/ad5504.c
@@ -300,6 +300,7 @@ static int ad5504_probe(struct spi_device *spi)
 	struct device *dev = &spi->dev;
 	struct iio_dev *indio_dev;
 	struct ad5504_state *st;
+	u32 range[2];
 	int ret;
 
 	indio_dev = devm_iio_device_alloc(dev, sizeof(*st));
@@ -315,12 +316,30 @@ static int ad5504_probe(struct spi_device *spi)
 	if (is_acpi_device_node(dev_fwnode(dev))) {
 		st->vref_mv = AD5504_VREF_ACPI_DEFAULT_mV;
 	} else {
-		ret = devm_regulator_get_enable_read_voltage(dev, "vcc");
-		if (ret < 0)
-			return dev_err_probe(dev, ret,
-					     "Failed to get vcc regulator\n");
-
-		st->vref_mv = ret / 1000;
+		if (device_property_present(dev, "output-range-microvolt")) {
+			ret = device_property_read_u32_array(dev, "output-range-microvolt",
+							     range, ARRAY_SIZE(range));
+			if (ret)
+				return dev_err_probe(dev, ret,
+							"Error parsing output-range-microvolt\n");
+
+			if (range[0] != 0 || (range[1] != 30 * MICRO && range[1] != 60 * MICRO))
+				return dev_err_probe(dev, -EINVAL,
+					"Invalid output-range-microvolt\n");
+
+			st->vref_mv = range[1] / (MICRO / MILLI);
+
+			ret = devm_regulator_get_enable(dev, "vcc");
+			if (ret < 0)
+				return dev_err_probe(dev, ret, "Failed to enable vcc regulator\n");
+		} else {
+			/* Backward compat: old DTs without output-range-microvolt */
+			ret = devm_regulator_get_enable_read_voltage(dev, "vcc");
+			if (ret < 0)
+				return dev_err_probe(dev, ret, "Failed to get vcc regulator\n");
+
+			st->vref_mv = ret / (MICRO / MILLI);
+		}
 	}
 
 	st->spi = spi;
-- 
2.55.0

Re: [PATCH v6 6/6] iio: dac: ad5504: support scale via output-range-microvolt property

[David Lechner]

On 8/22/26 3:56 AM, Taha Ed-Dafili wrote:
> The AD5504 output range is set by the R_SEL pin, not the VCC supply.
> Add support for 'output-range-microvolt' to set vref_mv directly from
> firmware. Use device_property_present() to distinguish absent from
> malformed property rather than relying on the ambiguous -EINVAL from
> device_property_read_u32_array(). Fall back to the vcc regulator
> voltage for old DTs that predate this property.
> 
> Signed-off-by: Taha Ed-Dafili <0rayn.dev@gmail.com>
> ---
>  drivers/iio/dac/ad5504.c | 31 +++++++++++++++++++++++++------
>  1 file changed, 25 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/iio/dac/ad5504.c b/drivers/iio/dac/ad5504.c
> index 74679feea385..d0a3dd4b000d 100644
> --- a/drivers/iio/dac/ad5504.c
> +++ b/drivers/iio/dac/ad5504.c
> @@ -300,6 +300,7 @@ static int ad5504_probe(struct spi_device *spi)
>  	struct device *dev = &spi->dev;
>  	struct iio_dev *indio_dev;
>  	struct ad5504_state *st;
> +	u32 range[2];
>  	int ret;
>  
>  	indio_dev = devm_iio_device_alloc(dev, sizeof(*st));
> @@ -315,12 +316,30 @@ static int ad5504_probe(struct spi_device *spi)
>  	if (is_acpi_device_node(dev_fwnode(dev))) {
>  		st->vref_mv = AD5504_VREF_ACPI_DEFAULT_mV;
>  	} else {
> -		ret = devm_regulator_get_enable_read_voltage(dev, "vcc");
> -		if (ret < 0)
> -			return dev_err_probe(dev, ret,
> -					     "Failed to get vcc regulator\n");
> -
> -		st->vref_mv = ret / 1000;
> +		if (device_property_present(dev, "output-range-microvolt")) {
> +			ret = device_property_read_u32_array(dev, "output-range-microvolt",
> +							     range, ARRAY_SIZE(range));
> +			if (ret)
> +				return dev_err_probe(dev, ret,
> +							"Error parsing output-range-microvolt\n");
> +
> +			if (range[0] != 0 || (range[1] != 30 * MICRO && range[1] != 60 * MICRO))
> +				return dev_err_probe(dev, -EINVAL,
> +					"Invalid output-range-microvolt\n");
> +
> +			st->vref_mv = range[1] / (MICRO / MILLI);
> +
> +			ret = devm_regulator_get_enable(dev, "vcc");
> +			if (ret < 0)
> +				return dev_err_probe(dev, ret, "Failed to enable vcc regulator\n");

We should probably handle range-sel-gpios here. Otherwise, if a new DT tries
to use it, it will end up falling back to this old wrong behavior.

		} else if (device_property_present("range-sel-gpios")) {
			
Either return an error here that it is not supported. Or implement it by
making IIO_CHAN_INFO_SCALE writable.

> +		} else {
> +			/* Backward compat: old DTs without output-range-microvolt */
> +			ret = devm_regulator_get_enable_read_voltage(dev, "vcc");
> +			if (ret < 0)
> +				return dev_err_probe(dev, ret, "Failed to get vcc regulator\n");
> +
> +			st->vref_mv = ret / (MICRO / MILLI);
> +		}
>  	}
>  
>  	st->spi = spi;

Re: [PATCH v6 6/6] iio: dac: ad5504: support scale via output-range-microvolt property

[Taha Ed-Dafili]

> We should probably handle range-sel-gpios here. Otherwise, if a new
> DT tries to use it, it will end up falling back to this old wrong
> behavior.
>
> Either return an error here that it is not supported. Or implement
> it by making IIO_CHAN_INFO_SCALE writable.

Thank you for catching that. For now I'll return an error in that
case, we can always expand it later if needed.

Best Regards,
Taha Ed-Dafili