[PATCH v4 0/2] staging: iio: frequency: ad9832: Fix and

[PATCH v4 0/2] staging: iio: frequency: ad9832: Fix and

[Gabriel Shahrouzi]

Patch 1 includes the initial fix.

Patch 2 refactors the code to use the out_altvoltage_powerdown ABI via
an extended attribute.

Gabriel Shahrouzi (2):
  iio: frequency: Use SLEEP bit instead of RESET to disable output
  staging: iio: ad9832: Refactor powerdown control

 drivers/staging/iio/frequency/ad9832.c | 69 +++++++++++++++++++-------
 1 file changed, 51 insertions(+), 18 deletions(-)

-- 
2.43.0

[PATCH v4 1/2] staging: iio: frequency: ad9832: Use SLEEP bit instead of RESET to disable output

[Gabriel Shahrouzi]

According to the AD9832 datasheet (Table 10, D12 description), setting
the RESET bit forces the phase accumulator to zero, which corresponds to
a full-scale DC output, rather than disabling the output signal.

The correct way to disable the output and enter a low-power state is to
set the AD9832_SLEEP bit (Table 10, D13 description), which powers down
the internal DAC current sources and disables internal clocks.

Fixes: ea707584bac1 ("Staging: IIO: DDS: AD9832 / AD9835 driver")
Cc: stable@vger.kernel.org
Signed-off-by: Gabriel Shahrouzi <gshahrouzi@gmail.com>
---
v3 -> v4:
	- Rebase changes ontop of most recent changes.
v2 -> v3:
v1 -> v2:
---
 drivers/staging/iio/frequency/ad9832.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/staging/iio/frequency/ad9832.c b/drivers/staging/iio/frequency/ad9832.c
index 49388da5a684a..2e555084ff98a 100644
--- a/drivers/staging/iio/frequency/ad9832.c
+++ b/drivers/staging/iio/frequency/ad9832.c
@@ -236,7 +236,7 @@ static ssize_t ad9832_write(struct device *dev, struct device_attribute *attr,
 		if (val)
 			st->ctrl_src &= ~(AD9832_RESET | AD9832_SLEEP | AD9832_CLR);
 		else
-			st->ctrl_src |= FIELD_PREP(AD9832_RESET, 1);
+			st->ctrl_src |= FIELD_PREP(AD9832_SLEEP, 1);
 
 		st->data = cpu_to_be16(FIELD_PREP(AD9832_CMD_MSK, AD9832_CMD_SLEEPRESCLR) |
 						  st->ctrl_src);
-- 
2.43.0

Re: [PATCH v4 1/2] staging: iio: frequency: ad9832: Use SLEEP bit instead of RESET to disable output

[Andy Shevchenko]

On Fri, Apr 25, 2025 at 1:34 AM Gabriel Shahrouzi <gshahrouzi@gmail.com> wrote:
>
> According to the AD9832 datasheet (Table 10, D12 description), setting
> the RESET bit forces the phase accumulator to zero, which corresponds to
> a full-scale DC output, rather than disabling the output signal.
>
> The correct way to disable the output and enter a low-power state is to
> set the AD9832_SLEEP bit (Table 10, D13 description), which powers down
> the internal DAC current sources and disables internal clocks.

...

>                 if (val)
>                         st->ctrl_src &= ~(AD9832_RESET | AD9832_SLEEP | AD9832_CLR);
>                 else
> -                       st->ctrl_src |= FIELD_PREP(AD9832_RESET, 1);
> +                       st->ctrl_src |= FIELD_PREP(AD9832_SLEEP, 1);

From the code perspective this allows combinations of the bits to be
set. So, what does the datasheet say about SLEEP+RESET, or RESET+CLR,
or other combinations of these 3 bits?

-- 
With Best Regards,
Andy Shevchenko

[PATCH v4 2/2] staging: iio: frequency: ad9832: Refactor powerdown control

[Gabriel Shahrouzi]

Replace custom implementation with out_altvoltage_powerdown ABI. The
attribute's logic is inverted (1 now enables powerdown) to match the
standard.

Signed-off-by: Gabriel Shahrouzi <gshahrouzi@gmail.com>
---
V3 -> v4:
	- Use guard(mutex) for simplified locking.
	- Use an extended attribute.
v2 -> v3:
v1 -> v2:
	Refactor powerdown functionality.
---
 drivers/staging/iio/frequency/ad9832.c | 69 +++++++++++++++++++-------
 1 file changed, 51 insertions(+), 18 deletions(-)

diff --git a/drivers/staging/iio/frequency/ad9832.c b/drivers/staging/iio/frequency/ad9832.c
index 2e555084ff98a..b8b52302abf36 100644
--- a/drivers/staging/iio/frequency/ad9832.c
+++ b/drivers/staging/iio/frequency/ad9832.c
@@ -174,6 +174,32 @@ static int ad9832_write_phase(struct ad9832_state *st,
 	return spi_sync(st->spi, &st->phase_msg);
 }
 
+static ssize_t ad9832_write_powerdown(struct iio_dev *indio_dev, uintptr_t private,
+				      const struct iio_chan_spec *chan,
+				      const char *buf, size_t len)
+{
+	struct ad9832_state *st = iio_priv(indio_dev);
+	int ret;
+	bool val;
+
+	ret = kstrtobool(buf, &val);
+	if (ret)
+		return ret;
+
+	guard(mutex)(&st->lock);
+	if (val)
+		st->ctrl_src |= AD9832_SLEEP;
+	else
+		st->ctrl_src &= ~(AD9832_RESET | AD9832_SLEEP |
+				 AD9832_CLR);
+
+	st->data = cpu_to_be16(FIELD_PREP(AD9832_CMD_MSK, AD9832_CMD_SLEEPRESCLR) |
+					  st->ctrl_src);
+	ret = spi_sync(st->spi, &st->msg);
+
+	return ret ? ret : len;
+}
+
 static ssize_t ad9832_write(struct device *dev, struct device_attribute *attr,
 			    const char *buf, size_t len)
 {
@@ -185,9 +211,9 @@ static ssize_t ad9832_write(struct device *dev, struct device_attribute *attr,
 
 	ret = kstrtoul(buf, 10, &val);
 	if (ret)
-		goto error_ret;
+		return ret;
 
-	mutex_lock(&st->lock);
+	guard(mutex)(&st->lock);
 	switch ((u32)this_attr->address) {
 	case AD9832_FREQ0HM:
 	case AD9832_FREQ1HM:
@@ -232,22 +258,9 @@ static ssize_t ad9832_write(struct device *dev, struct device_attribute *attr,
 						  st->ctrl_fp);
 		ret = spi_sync(st->spi, &st->msg);
 		break;
-	case AD9832_OUTPUT_EN:
-		if (val)
-			st->ctrl_src &= ~(AD9832_RESET | AD9832_SLEEP | AD9832_CLR);
-		else
-			st->ctrl_src |= FIELD_PREP(AD9832_SLEEP, 1);
-
-		st->data = cpu_to_be16(FIELD_PREP(AD9832_CMD_MSK, AD9832_CMD_SLEEPRESCLR) |
-						  st->ctrl_src);
-		ret = spi_sync(st->spi, &st->msg);
-		break;
 	default:
 		ret = -ENODEV;
 	}
-	mutex_unlock(&st->lock);
-
-error_ret:
 	return ret ? ret : len;
 }
 
@@ -270,8 +283,6 @@ static IIO_CONST_ATTR_PHASE_SCALE(0, "0.0015339808"); /* 2PI/2^12 rad*/
 
 static IIO_DEV_ATTR_PINCONTROL_EN(0, 0200, NULL,
 				ad9832_write, AD9832_PINCTRL_EN);
-static IIO_DEV_ATTR_OUT_ENABLE(0, 0200, NULL,
-				ad9832_write, AD9832_OUTPUT_EN);
 
 static struct attribute *ad9832_attributes[] = {
 	&iio_dev_attr_out_altvoltage0_frequency0.dev_attr.attr,
@@ -285,7 +296,6 @@ static struct attribute *ad9832_attributes[] = {
 	&iio_dev_attr_out_altvoltage0_pincontrol_en.dev_attr.attr,
 	&iio_dev_attr_out_altvoltage0_frequencysymbol.dev_attr.attr,
 	&iio_dev_attr_out_altvoltage0_phasesymbol.dev_attr.attr,
-	&iio_dev_attr_out_altvoltage0_out_enable.dev_attr.attr,
 	NULL,
 };
 
@@ -293,6 +303,27 @@ static const struct attribute_group ad9832_attribute_group = {
 	.attrs = ad9832_attributes,
 };
 
+static const struct iio_chan_spec_ext_info ad9832_ext_info[] = {
+	{
+		.name = "powerdown",
+		.shared = IIO_SEPARATE,
+		.write = ad9832_write_powerdown,
+	},
+	{ },
+};
+
+#define AD9832_CHANNEL(chan) {					\
+	.type = IIO_ALTVOLTAGE,					\
+	.indexed = 1,						\
+	.output = 1,						\
+	.channel = (chan),					\
+	.ext_info = ad9832_ext_info,				\
+}
+
+static const struct iio_chan_spec ad9832_channels[] = {
+	AD9832_CHANNEL(0),
+};
+
 static const struct iio_info ad9832_info = {
 	.attrs = &ad9832_attribute_group,
 };
@@ -333,6 +364,8 @@ static int ad9832_probe(struct spi_device *spi)
 	indio_dev->name = spi_get_device_id(spi)->name;
 	indio_dev->info = &ad9832_info;
 	indio_dev->modes = INDIO_DIRECT_MODE;
+	indio_dev->channels = ad9832_channels;
+	indio_dev->num_channels = ARRAY_SIZE(ad9832_channels);
 
 	/* Setup default messages */
 
-- 
2.43.0

Re: [PATCH v4 2/2] staging: iio: frequency: ad9832: Refactor powerdown control

[Andy Shevchenko]

On Fri, Apr 25, 2025 at 1:34 AM Gabriel Shahrouzi <gshahrouzi@gmail.com> wrote:
>
> Replace custom implementation with out_altvoltage_powerdown ABI. The
> attribute's logic is inverted (1 now enables powerdown) to match the
> standard.


> +static ssize_t ad9832_write_powerdown(struct iio_dev *indio_dev, uintptr_t private,
> +                                     const struct iio_chan_spec *chan,
> +                                     const char *buf, size_t len)
> +{
> +       struct ad9832_state *st = iio_priv(indio_dev);
> +       int ret;
> +       bool val;
> +
> +       ret = kstrtobool(buf, &val);
> +       if (ret)
> +               return ret;
> +
> +       guard(mutex)(&st->lock);

> +       if (val)
> +               st->ctrl_src |= AD9832_SLEEP;
> +       else
> +               st->ctrl_src &= ~(AD9832_RESET | AD9832_SLEEP |
> +                                AD9832_CLR);

Why out of a sudden this went backwards in style and format (no
FIELD_PREP(), two lines, ...)?

> +
> +       st->data = cpu_to_be16(FIELD_PREP(AD9832_CMD_MSK, AD9832_CMD_SLEEPRESCLR) |
> +                                         st->ctrl_src);
> +       ret = spi_sync(st->spi, &st->msg);
> +
> +       return ret ? ret : len;
> +}

Use Elvis?

...

> -       mutex_lock(&st->lock);
> +       guard(mutex)(&st->lock);

This should be done in a separate patch for all locking.

...

> -                       st->ctrl_src |= FIELD_PREP(AD9832_SLEEP, 1);

Btw, I do not see this in v6.15-tcX, is this part of Linux Next?

...


>         &iio_dev_attr_out_altvoltage0_pincontrol_en.dev_attr.attr,
>         &iio_dev_attr_out_altvoltage0_frequencysymbol.dev_attr.attr,
>         &iio_dev_attr_out_altvoltage0_phasesymbol.dev_attr.attr,
> -       &iio_dev_attr_out_altvoltage0_out_enable.dev_attr.attr,

>         NULL,

Also drop the trailing comma at some point.

...

> +static const struct iio_chan_spec_ext_info ad9832_ext_info[] = {
> +       {
> +               .name = "powerdown",
> +               .shared = IIO_SEPARATE,
> +               .write = ad9832_write_powerdown,
> +       },

> +       { },

Ditto.

> +};

-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH v4 2/2] staging: iio: frequency: ad9832: Refactor powerdown control

[Dan Carpenter]

On Thu, Apr 24, 2025 at 06:32:09PM -0400, Gabriel Shahrouzi wrote:
> Replace custom implementation with out_altvoltage_powerdown ABI. The
> attribute's logic is inverted (1 now enables powerdown) to match the
> standard.
> 
> Signed-off-by: Gabriel Shahrouzi <gshahrouzi@gmail.com>
> ---
> V3 -> v4:
> 	- Use guard(mutex) for simplified locking.
> 	- Use an extended attribute.
> v2 -> v3:
> v1 -> v2:
> 	Refactor powerdown functionality.
> ---
>  drivers/staging/iio/frequency/ad9832.c | 69 +++++++++++++++++++-------
>  1 file changed, 51 insertions(+), 18 deletions(-)
> 
> diff --git a/drivers/staging/iio/frequency/ad9832.c b/drivers/staging/iio/frequency/ad9832.c
> index 2e555084ff98a..b8b52302abf36 100644
> --- a/drivers/staging/iio/frequency/ad9832.c
> +++ b/drivers/staging/iio/frequency/ad9832.c
> @@ -174,6 +174,32 @@ static int ad9832_write_phase(struct ad9832_state *st,
>  	return spi_sync(st->spi, &st->phase_msg);
>  }
>  
> +static ssize_t ad9832_write_powerdown(struct iio_dev *indio_dev, uintptr_t private,
> +				      const struct iio_chan_spec *chan,
> +				      const char *buf, size_t len)
> +{
> +	struct ad9832_state *st = iio_priv(indio_dev);
> +	int ret;
> +	bool val;

Declare val before ret.  Use reverse Christmas tree order.

	long long long_name;
	medium name;
	short name;

> +
> +	ret = kstrtobool(buf, &val);
> +	if (ret)
> +		return ret;
> +
> +	guard(mutex)(&st->lock);
> +	if (val)
> +		st->ctrl_src |= AD9832_SLEEP;
> +	else
> +		st->ctrl_src &= ~(AD9832_RESET | AD9832_SLEEP |
> +				 AD9832_CLR);
> +
> +	st->data = cpu_to_be16(FIELD_PREP(AD9832_CMD_MSK, AD9832_CMD_SLEEPRESCLR) |
> +					  st->ctrl_src);
> +	ret = spi_sync(st->spi, &st->msg);
> +
> +	return ret ? ret : len;
> +}
> +
>  static ssize_t ad9832_write(struct device *dev, struct device_attribute *attr,
>  			    const char *buf, size_t len)
>  {
> @@ -185,9 +211,9 @@ static ssize_t ad9832_write(struct device *dev, struct device_attribute *attr,
>  
>  	ret = kstrtoul(buf, 10, &val);
>  	if (ret)
> -		goto error_ret;
> +		return ret;

This is unrelated.  Do this in a separate patch.

>  
> -	mutex_lock(&st->lock);
> +	guard(mutex)(&st->lock);

same.

>  	switch ((u32)this_attr->address) {
>  	case AD9832_FREQ0HM:
>  	case AD9832_FREQ1HM:
> @@ -232,22 +258,9 @@ static ssize_t ad9832_write(struct device *dev, struct device_attribute *attr,
>  						  st->ctrl_fp);
>  		ret = spi_sync(st->spi, &st->msg);
>  		break;
> -	case AD9832_OUTPUT_EN:
> -		if (val)
> -			st->ctrl_src &= ~(AD9832_RESET | AD9832_SLEEP | AD9832_CLR);
> -		else
> -			st->ctrl_src |= FIELD_PREP(AD9832_SLEEP, 1);
> -
> -		st->data = cpu_to_be16(FIELD_PREP(AD9832_CMD_MSK, AD9832_CMD_SLEEPRESCLR) |
> -						  st->ctrl_src);
> -		ret = spi_sync(st->spi, &st->msg);
> -		break;

This is related.  Keep this.

>  	default:
>  		ret = -ENODEV;
>  	}
> -	mutex_unlock(&st->lock);
> -
> -error_ret:
>  	return ret ? ret : len;

Unrelated.

>  }
>  
> @@ -270,8 +283,6 @@ static IIO_CONST_ATTR_PHASE_SCALE(0, "0.0015339808"); /* 2PI/2^12 rad*/
>  
>  static IIO_DEV_ATTR_PINCONTROL_EN(0, 0200, NULL,
>  				ad9832_write, AD9832_PINCTRL_EN);
> -static IIO_DEV_ATTR_OUT_ENABLE(0, 0200, NULL,
> -				ad9832_write, AD9832_OUTPUT_EN);
>  
>  static struct attribute *ad9832_attributes[] = {
>  	&iio_dev_attr_out_altvoltage0_frequency0.dev_attr.attr,
> @@ -285,7 +296,6 @@ static struct attribute *ad9832_attributes[] = {
>  	&iio_dev_attr_out_altvoltage0_pincontrol_en.dev_attr.attr,
>  	&iio_dev_attr_out_altvoltage0_frequencysymbol.dev_attr.attr,
>  	&iio_dev_attr_out_altvoltage0_phasesymbol.dev_attr.attr,
> -	&iio_dev_attr_out_altvoltage0_out_enable.dev_attr.attr,
>  	NULL,
>  };
>  
> @@ -293,6 +303,27 @@ static const struct attribute_group ad9832_attribute_group = {
>  	.attrs = ad9832_attributes,
>  };
>  
> +static const struct iio_chan_spec_ext_info ad9832_ext_info[] = {
> +	{
> +		.name = "powerdown",
> +		.shared = IIO_SEPARATE,
> +		.write = ad9832_write_powerdown,
> +	},
> +	{ },
           ^
No comma after a sentinal.

> +};
> +

regards,
dan carpenter

Re: [PATCH v4 0/2] staging: iio: frequency: ad9832: Fix and

[Gabriel Shahrouzi]

On Thu, Apr 24, 2025 at 6:34 PM Gabriel Shahrouzi <gshahrouzi@gmail.com> wrote:
>
> Patch 1 includes the initial fix.
>
> Patch 2 refactors the code to use the out_altvoltage_powerdown ABI via
> an extended attribute.
>
> Gabriel Shahrouzi (2):
>   iio: frequency: Use SLEEP bit instead of RESET to disable output
>   staging: iio: ad9832: Refactor powerdown control
>
>  drivers/staging/iio/frequency/ad9832.c | 69 +++++++++++++++++++-------
>  1 file changed, 51 insertions(+), 18 deletions(-)
>
> --
> 2.43.0
>
Whoops. Didn't realize reformatting the title on the cover letter so
it fits within the width requirement would cause part of title to be
omitted. Title should be: Subject: [PATCH v4 0/2] staging: iio:
frequency: ad9832: Fix and refactor output disable logic.