[PATCH] iio: dac: ad3530r: Fix incorrect masking for channels 4-7 in powerdown mode

[PATCH] iio: dac: ad3530r: Fix incorrect masking for channels 4-7 in powerdown mode

[Kim Seer Paller]

In the current implementation of ad3530r_set_dac_powerdown() function,
the macro AD3530R_OP_MODE_CHAN_MSK(chan->channel) is used to generate
the bitmask for the operating mode of a specific channel. However, this
macro does not account for channels 4-7, which map to the second
register AD3530R_OUTPUT_OPERATING_MODE_1 for the 8 channeled device. As
a result, the bitmask is incorrectly calculated for these channels,
leading to improper configuration of the powerdown mode. Resolve this
issue by adjusting the channel index for channels 4-7 by subtracting 4
before applying the macro. This ensures that the correct bitmask is
generated for the second register.

Fixes: 93583174a3df ("iio: dac: ad3530r: Add driver for AD3530R and AD3531R")
Signed-off-by: Kim Seer Paller <kimseer.paller@analog.com>
---
 drivers/iio/dac/ad3530r.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/iio/dac/ad3530r.c b/drivers/iio/dac/ad3530r.c
index f9752a571aa53ca0d7e199ed6a78550358185bf9..6134613777b8e1d4516109b74e0b3b79edb1ae75 100644
--- a/drivers/iio/dac/ad3530r.c
+++ b/drivers/iio/dac/ad3530r.c
@@ -166,7 +166,9 @@ static ssize_t ad3530r_set_dac_powerdown(struct iio_dev *indio_dev,
 	      AD3530R_OUTPUT_OPERATING_MODE_0 :
 	      AD3530R_OUTPUT_OPERATING_MODE_1;
 	pdmode = powerdown ? st->chan[chan->channel].powerdown_mode : 0;
-	mask = AD3530R_OP_MODE_CHAN_MSK(chan->channel);
+	mask = chan->channel < AD3531R_MAX_CHANNELS ?
+	       AD3530R_OP_MODE_CHAN_MSK(chan->channel) :
+	       AD3530R_OP_MODE_CHAN_MSK(chan->channel - 4);
 	val = field_prep(mask, pdmode);
 
 	ret = regmap_update_bits(st->regmap, reg, mask, val);

---
base-commit: 0a2857e778599c2794dc89c40dc79ead631b34df
change-id: 20250626-bug_fix-404361f2f190

Best regards,
-- 
Kim Seer Paller <kimseer.paller@analog.com>

Re: [PATCH] iio: dac: ad3530r: Fix incorrect masking for channels 4-7 in powerdown mode

[David Lechner]

On 6/26/25 3:38 AM, Kim Seer Paller wrote:
> In the current implementation of ad3530r_set_dac_powerdown() function,
> the macro AD3530R_OP_MODE_CHAN_MSK(chan->channel) is used to generate
> the bitmask for the operating mode of a specific channel. However, this
> macro does not account for channels 4-7, which map to the second
> register AD3530R_OUTPUT_OPERATING_MODE_1 for the 8 channeled device. As
> a result, the bitmask is incorrectly calculated for these channels,
> leading to improper configuration of the powerdown mode. Resolve this
> issue by adjusting the channel index for channels 4-7 by subtracting 4
> before applying the macro. This ensures that the correct bitmask is
> generated for the second register.
> 
> Fixes: 93583174a3df ("iio: dac: ad3530r: Add driver for AD3530R and AD3531R")
> Signed-off-by: Kim Seer Paller <kimseer.paller@analog.com>
> ---

Reviewed-by: David Lechner <dlechner@baylibre.com>

Re: [PATCH] iio: dac: ad3530r: Fix incorrect masking for channels 4-7 in powerdown mode

[Nuno Sá]

On Thu, 2025-06-26 at 16:38 +0800, Kim Seer Paller wrote:
> In the current implementation of ad3530r_set_dac_powerdown() function,
> the macro AD3530R_OP_MODE_CHAN_MSK(chan->channel) is used to generate
> the bitmask for the operating mode of a specific channel. However, this
> macro does not account for channels 4-7, which map to the second
> register AD3530R_OUTPUT_OPERATING_MODE_1 for the 8 channeled device. As
> a result, the bitmask is incorrectly calculated for these channels,
> leading to improper configuration of the powerdown mode. Resolve this
> issue by adjusting the channel index for channels 4-7 by subtracting 4
> before applying the macro. This ensures that the correct bitmask is
> generated for the second register.
> 
> Fixes: 93583174a3df ("iio: dac: ad3530r: Add driver for AD3530R and AD3531R")
> Signed-off-by: Kim Seer Paller <kimseer.paller@analog.com>
> ---

LGTM,

Reviewed-by: Nuno Sá <nuno.sa@analog.com>

>  drivers/iio/dac/ad3530r.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/iio/dac/ad3530r.c b/drivers/iio/dac/ad3530r.c
> index
> f9752a571aa53ca0d7e199ed6a78550358185bf9..6134613777b8e1d4516109b74e0b3b79edb1
> ae75 100644
> --- a/drivers/iio/dac/ad3530r.c
> +++ b/drivers/iio/dac/ad3530r.c
> @@ -166,7 +166,9 @@ static ssize_t ad3530r_set_dac_powerdown(struct iio_dev
> *indio_dev,
>  	      AD3530R_OUTPUT_OPERATING_MODE_0 :
>  	      AD3530R_OUTPUT_OPERATING_MODE_1;
>  	pdmode = powerdown ? st->chan[chan->channel].powerdown_mode : 0;
> -	mask = AD3530R_OP_MODE_CHAN_MSK(chan->channel);
> +	mask = chan->channel < AD3531R_MAX_CHANNELS ?
> +	       AD3530R_OP_MODE_CHAN_MSK(chan->channel) :
> +	       AD3530R_OP_MODE_CHAN_MSK(chan->channel - 4);
>  	val = field_prep(mask, pdmode);
>  
>  	ret = regmap_update_bits(st->regmap, reg, mask, val);
> 
> ---
> base-commit: 0a2857e778599c2794dc89c40dc79ead631b34df
> change-id: 20250626-bug_fix-404361f2f190
> 
> Best regards,

Re: [PATCH] iio: dac: ad3530r: Fix incorrect masking for channels 4-7 in powerdown mode

[Jonathan Cameron]

On Fri, 27 Jun 2025 16:54:33 +0100
Nuno Sá <noname.nuno@gmail.com> wrote:

> On Thu, 2025-06-26 at 16:38 +0800, Kim Seer Paller wrote:
> > In the current implementation of ad3530r_set_dac_powerdown() function,
> > the macro AD3530R_OP_MODE_CHAN_MSK(chan->channel) is used to generate
> > the bitmask for the operating mode of a specific channel. However, this
> > macro does not account for channels 4-7, which map to the second
> > register AD3530R_OUTPUT_OPERATING_MODE_1 for the 8 channeled device. As
> > a result, the bitmask is incorrectly calculated for these channels,
> > leading to improper configuration of the powerdown mode. Resolve this
> > issue by adjusting the channel index for channels 4-7 by subtracting 4
> > before applying the macro. This ensures that the correct bitmask is
> > generated for the second register.
> > 
> > Fixes: 93583174a3df ("iio: dac: ad3530r: Add driver for AD3530R and AD3531R")
> > Signed-off-by: Kim Seer Paller <kimseer.paller@analog.com>
> > ---  
> 
> LGTM,
> 
> Reviewed-by: Nuno Sá <nuno.sa@analog.com>
Applied to the fixes-togreg branch of iio.git and marked for stable.

Thanks,

Jonathan