[PATCH][RESEND] staging: iio: adc: ad7192: disable burnout currents on misconfig

[PATCH][RESEND] staging: iio: adc: ad7192: disable burnout currents on misconfig

[alexandru.ardelean]

From: Alexandru Ardelean <alexandru.ardelean@analog.com>

According to the datasheet for all ad719x ADCs,
the burnout currents can be enabled only if buffer is enabled
and CHOP is disabled.

So, if neither of these conditions are met, then
we should disable the burnout currents in the driver as well,
and warn the user.

This change doesn't fix anything.
The burnout currents simply won't work if CHOP is enabled
or buffer is disabled.
The intent is to provide the user with some feedback
instead of silently not working inside the chip.

This is especially useful when considering device-tree
support (and/or device-tree overlays) at a later point,
which will allow for a quicker/simpler reconfiguration
of the chip settings.

Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
---
 drivers/staging/iio/adc/ad7192.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/staging/iio/adc/ad7192.c b/drivers/staging/iio/adc/ad7192.c
index d11c6de9c777..7f204013d6d4 100644
--- a/drivers/staging/iio/adc/ad7192.c
+++ b/drivers/staging/iio/adc/ad7192.c
@@ -266,6 +266,12 @@ static int ad7192_setup(struct ad7192_state *st,
 
 	st->conf = AD7192_CONF_GAIN(0);
 
+	if (pdata->burnout_curr_en && (!pdata->buf_en || pdata->chop_en)) {
+		pdata->burnout_curr_en = false;
+		dev_warn(dev,
+			 "Can't enable burnout currents: see CHOP or buffer\n");
+	}
+
 	if (pdata->rej60_en)
 		st->mode |= AD7192_MODE_REJ60;
 
-- 
2.14.1

Re: [PATCH][RESEND] staging: iio: adc: ad7192: disable burnout currents on misconfig

[Jonathan Cameron]

On Tue, 16 Jan 2018 12:04:37 +0200
<alexandru.ardelean@analog.com> wrote:

> From: Alexandru Ardelean <alexandru.ardelean@analog.com>
> 

Firstly, even a change to a description makes this a V2 patch
not a resend.  Resends should be identical and only occur if
either:
1) Someone asks you to resend for some reason (wrong cc's perhaps)
2) It has been a long time since anyone responded and looks like
your series has been forgotten.

> According to the datasheet for all ad719x ADCs,
> the burnout currents can be enabled only if buffer is enabled
> and CHOP is disabled.
> 
> So, if neither of these conditions are met, then
> we should disable the burnout currents in the driver as well,
> and warn the user.
> 
> This change doesn't fix anything.
> The burnout currents simply won't work if CHOP is enabled
> or buffer is disabled.
> The intent is to provide the user with some feedback
> instead of silently not working inside the chip.
> 
> This is especially useful when considering device-tree
> support (and/or device-tree overlays) at a later point,
> which will allow for a quicker/simpler reconfiguration
> of the chip settings.
> 
> Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Thanks, much better description. I'll pick this up when I'm next
on the correct PC (possibly not until the weekend).

Jonathan

> ---
>  drivers/staging/iio/adc/ad7192.c | 6 ++++++
>  1 file changed, 6 insertions(+)
> 
> diff --git a/drivers/staging/iio/adc/ad7192.c b/drivers/staging/iio/adc/ad7192.c
> index d11c6de9c777..7f204013d6d4 100644
> --- a/drivers/staging/iio/adc/ad7192.c
> +++ b/drivers/staging/iio/adc/ad7192.c
> @@ -266,6 +266,12 @@ static int ad7192_setup(struct ad7192_state *st,
>  
>  	st->conf = AD7192_CONF_GAIN(0);
>  
> +	if (pdata->burnout_curr_en && (!pdata->buf_en || pdata->chop_en)) {
> +		pdata->burnout_curr_en = false;
> +		dev_warn(dev,
> +			 "Can't enable burnout currents: see CHOP or buffer\n");
> +	}
> +
>  	if (pdata->rej60_en)
>  		st->mode |= AD7192_MODE_REJ60;
>  

Re: [PATCH][RESEND] staging: iio: adc: ad7192: disable burnout currents on misconfig

[Ardelean, Alexandru]
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