diff mbox series

[v5,6/9] iio: adc: ad7606: rework available attributes for SW channels

Message ID 20240907065043.771364-7-aardelean@baylibre.com (mailing list archive)
State Changes Requested
Headers show
Series iio: adc: ad7606: add support for AD7606C-{16,18} parts | expand

Commit Message

Alexandru Ardelean Sept. 7, 2024, 6:50 a.m. UTC
For SW mode, the oversampling and scales attributes are always present.
So, they can be implemented via a 'read_avail' hook in iio_info.

For HW mode, it's a bit tricky, as these attributes get assigned based on
GPIO definitions.

So, for SW mode, we define a separate AD7606_SW_CHANNEL() macro, and use
that for the SW channels.
And 'ad7606_info_os_range_and_debug' can be renamed to
'ad7606_info_sw_mode' as it is only used for SW mode.

For the 'read_avail' hook, we'll need to allocate the SW scales, so that
they are just returned userspace without any extra processing.
The allocation will happen when then ad7606_state struct is allocated.
The oversampling available parameters don't need any extra processing; they
can just be passed back to userspace (as they are).

Signed-off-by: Alexandru Ardelean <aardelean@baylibre.com>
---
 drivers/iio/adc/ad7606.c | 63 ++++++++++++++++++++++++++++++++++++----
 drivers/iio/adc/ad7606.h | 31 +++++++++++++++++---
 2 files changed, 85 insertions(+), 9 deletions(-)

Comments

Jonathan Cameron Sept. 7, 2024, 3:03 p.m. UTC | #1
On Sat,  7 Sep 2024 09:50:39 +0300
Alexandru Ardelean <aardelean@baylibre.com> wrote:

> For SW mode, the oversampling and scales attributes are always present.
> So, they can be implemented via a 'read_avail' hook in iio_info.
> 
> For HW mode, it's a bit tricky, as these attributes get assigned based on
> GPIO definitions.
> 
> So, for SW mode, we define a separate AD7606_SW_CHANNEL() macro, and use
> that for the SW channels.
> And 'ad7606_info_os_range_and_debug' can be renamed to
> 'ad7606_info_sw_mode' as it is only used for SW mode.
> 
> For the 'read_avail' hook, we'll need to allocate the SW scales, so that
> they are just returned userspace without any extra processing.
> The allocation will happen when then ad7606_state struct is allocated.
> The oversampling available parameters don't need any extra processing; they
> can just be passed back to userspace (as they are).
> 
> Signed-off-by: Alexandru Ardelean <aardelean@baylibre.com>

One question inline.

>  
>  int ad7606_probe(struct device *dev, int irq, void __iomem *base_address,
> diff --git a/drivers/iio/adc/ad7606.h b/drivers/iio/adc/ad7606.h
> index 635407c2acc0..fa175cff256c 100644
> --- a/drivers/iio/adc/ad7606.h
> +++ b/drivers/iio/adc/ad7606.h

>  #define AD7616_CHANNEL(num)	AD7606_SW_CHANNEL(num, 16)
>  
>  /**
> @@ -65,11 +84,15 @@ struct ad7606_chip_info {
>  /**
>   * struct ad7606_chan_scale - channel scale configuration
>   * @scale_avail		pointer to the array which stores the available scales
> + * @scale_avail_show	a duplicate of 'scale_avail' which is readily formatted
> + *			such that it can be read via the 'read_avail' hook
>   * @num_scales		number of elements stored in the scale_avail array
>   * @range		voltage range selection, selects which scale to apply
>   */
>  struct ad7606_chan_scale {
> +#define AD760X_MAX_SCALE_SHOW		(AD760X_MAX_CHANNELS * 2)

Why is the number of scales dependent on the number of channels?

>  	const unsigned int		*scale_avail;
> +	int				scale_avail_show[AD760X_MAX_SCALE_SHOW];
>  	unsigned int			num_scales;
>  	unsigned int			range;
>  };
Alexandru Ardelean Sept. 7, 2024, 6:10 p.m. UTC | #2
On Sat, Sep 7, 2024 at 6:04 PM Jonathan Cameron <jic23@kernel.org> wrote:
>
> On Sat,  7 Sep 2024 09:50:39 +0300
> Alexandru Ardelean <aardelean@baylibre.com> wrote:
>
> > For SW mode, the oversampling and scales attributes are always present.
> > So, they can be implemented via a 'read_avail' hook in iio_info.
> >
> > For HW mode, it's a bit tricky, as these attributes get assigned based on
> > GPIO definitions.
> >
> > So, for SW mode, we define a separate AD7606_SW_CHANNEL() macro, and use
> > that for the SW channels.
> > And 'ad7606_info_os_range_and_debug' can be renamed to
> > 'ad7606_info_sw_mode' as it is only used for SW mode.
> >
> > For the 'read_avail' hook, we'll need to allocate the SW scales, so that
> > they are just returned userspace without any extra processing.
> > The allocation will happen when then ad7606_state struct is allocated.
> > The oversampling available parameters don't need any extra processing; they
> > can just be passed back to userspace (as they are).
> >
> > Signed-off-by: Alexandru Ardelean <aardelean@baylibre.com>
>
> One question inline.
>
> >
> >  int ad7606_probe(struct device *dev, int irq, void __iomem *base_address,
> > diff --git a/drivers/iio/adc/ad7606.h b/drivers/iio/adc/ad7606.h
> > index 635407c2acc0..fa175cff256c 100644
> > --- a/drivers/iio/adc/ad7606.h
> > +++ b/drivers/iio/adc/ad7606.h
>
> >  #define AD7616_CHANNEL(num)  AD7606_SW_CHANNEL(num, 16)
> >
> >  /**
> > @@ -65,11 +84,15 @@ struct ad7606_chip_info {
> >  /**
> >   * struct ad7606_chan_scale - channel scale configuration
> >   * @scale_avail              pointer to the array which stores the available scales
> > + * @scale_avail_show a duplicate of 'scale_avail' which is readily formatted
> > + *                   such that it can be read via the 'read_avail' hook
> >   * @num_scales               number of elements stored in the scale_avail array
> >   * @range            voltage range selection, selects which scale to apply
> >   */
> >  struct ad7606_chan_scale {
> > +#define AD760X_MAX_SCALE_SHOW                (AD760X_MAX_CHANNELS * 2)
>
> Why is the number of scales dependent on the number of channels?

Well, that was just a lazy implementation.
I doubt there would be 16 scales (channel range values) for any newer part.
A value for a channel-range is 4-bits (for 0 to 15).

In IIO the current highest scale-count is 5; I guess I can update this
to a macro, and use that.


>
> >       const unsigned int              *scale_avail;
> > +     int                             scale_avail_show[AD760X_MAX_SCALE_SHOW];
> >       unsigned int                    num_scales;
> >       unsigned int                    range;
> >  };
>
Jonathan Cameron Sept. 8, 2024, 10:47 a.m. UTC | #3
On Sat, 7 Sep 2024 21:10:10 +0300
Alexandru Ardelean <aardelean@baylibre.com> wrote:

> On Sat, Sep 7, 2024 at 6:04 PM Jonathan Cameron <jic23@kernel.org> wrote:
> >
> > On Sat,  7 Sep 2024 09:50:39 +0300
> > Alexandru Ardelean <aardelean@baylibre.com> wrote:
> >  
> > > For SW mode, the oversampling and scales attributes are always present.
> > > So, they can be implemented via a 'read_avail' hook in iio_info.
> > >
> > > For HW mode, it's a bit tricky, as these attributes get assigned based on
> > > GPIO definitions.
> > >
> > > So, for SW mode, we define a separate AD7606_SW_CHANNEL() macro, and use
> > > that for the SW channels.
> > > And 'ad7606_info_os_range_and_debug' can be renamed to
> > > 'ad7606_info_sw_mode' as it is only used for SW mode.
> > >
> > > For the 'read_avail' hook, we'll need to allocate the SW scales, so that
> > > they are just returned userspace without any extra processing.
> > > The allocation will happen when then ad7606_state struct is allocated.
> > > The oversampling available parameters don't need any extra processing; they
> > > can just be passed back to userspace (as they are).
> > >
> > > Signed-off-by: Alexandru Ardelean <aardelean@baylibre.com>  
> >
> > One question inline.
> >  
> > >
> > >  int ad7606_probe(struct device *dev, int irq, void __iomem *base_address,
> > > diff --git a/drivers/iio/adc/ad7606.h b/drivers/iio/adc/ad7606.h
> > > index 635407c2acc0..fa175cff256c 100644
> > > --- a/drivers/iio/adc/ad7606.h
> > > +++ b/drivers/iio/adc/ad7606.h  
> >  
> > >  #define AD7616_CHANNEL(num)  AD7606_SW_CHANNEL(num, 16)
> > >
> > >  /**
> > > @@ -65,11 +84,15 @@ struct ad7606_chip_info {
> > >  /**
> > >   * struct ad7606_chan_scale - channel scale configuration
> > >   * @scale_avail              pointer to the array which stores the available scales
> > > + * @scale_avail_show a duplicate of 'scale_avail' which is readily formatted
> > > + *                   such that it can be read via the 'read_avail' hook
> > >   * @num_scales               number of elements stored in the scale_avail array
> > >   * @range            voltage range selection, selects which scale to apply
> > >   */
> > >  struct ad7606_chan_scale {
> > > +#define AD760X_MAX_SCALE_SHOW                (AD760X_MAX_CHANNELS * 2)  
> >
> > Why is the number of scales dependent on the number of channels?  
> 
> Well, that was just a lazy implementation.
> I doubt there would be 16 scales (channel range values) for any newer part.
> A value for a channel-range is 4-bits (for 0 to 15).
> 
> In IIO the current highest scale-count is 5; I guess I can update this
> to a macro, and use that.
Indeed defining this as 16 would make more sense than basing it on random
unconnected thing!

Jonathan

> 
> 
> >  
> > >       const unsigned int              *scale_avail;
> > > +     int                             scale_avail_show[AD760X_MAX_SCALE_SHOW];
> > >       unsigned int                    num_scales;
> > >       unsigned int                    range;
> > >  };  
> >
diff mbox series

Patch

diff --git a/drivers/iio/adc/ad7606.c b/drivers/iio/adc/ad7606.c
index 39ef72a8acd2..364f16fb96bf 100644
--- a/drivers/iio/adc/ad7606.c
+++ b/drivers/iio/adc/ad7606.c
@@ -483,6 +483,37 @@  static int ad7606_buffer_predisable(struct iio_dev *indio_dev)
 	return 0;
 }
 
+static int ad7606_read_avail(struct iio_dev *indio_dev,
+			     struct iio_chan_spec const *chan,
+			     const int **vals, int *type, int *length,
+			     long info)
+{
+	struct ad7606_state *st = iio_priv(indio_dev);
+	struct ad7606_chan_scale *cs;
+	unsigned int ch = 0;
+
+	switch (info) {
+	case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
+		*vals = st->oversampling_avail;
+		*length = st->num_os_ratios;
+		*type = IIO_VAL_INT;
+
+		return IIO_AVAIL_LIST;
+
+	case IIO_CHAN_INFO_SCALE:
+		if (st->sw_mode_en)
+			ch = chan->address;
+
+		cs = &st->chan_scales[ch];
+		*vals = cs->scale_avail_show;
+		*length = cs->num_scales * 2;
+		*type = IIO_VAL_INT_PLUS_MICRO;
+
+		return IIO_AVAIL_LIST;
+	}
+	return -EINVAL;
+}
+
 static const struct iio_buffer_setup_ops ad7606_buffer_ops = {
 	.postenable = &ad7606_buffer_postenable,
 	.predisable = &ad7606_buffer_predisable,
@@ -500,11 +531,11 @@  static const struct iio_info ad7606_info_os_and_range = {
 	.validate_trigger = &ad7606_validate_trigger,
 };
 
-static const struct iio_info ad7606_info_os_range_and_debug = {
+static const struct iio_info ad7606_info_sw_mode = {
 	.read_raw = &ad7606_read_raw,
 	.write_raw = &ad7606_write_raw,
+	.read_avail = &ad7606_read_avail,
 	.debugfs_reg_access = &ad7606_reg_access,
-	.attrs = &ad7606_attribute_group_os_and_range,
 	.validate_trigger = &ad7606_validate_trigger,
 };
 
@@ -530,7 +561,7 @@  static int ad7606_sw_mode_setup(struct iio_dev *indio_dev)
 {
 	unsigned int num_channels = indio_dev->num_channels - 1;
 	struct ad7606_state *st = iio_priv(indio_dev);
-	int ch;
+	int ret, ch;
 
 	if (!st->bops->sw_mode_config)
 		return 0;
@@ -539,7 +570,7 @@  static int ad7606_sw_mode_setup(struct iio_dev *indio_dev)
 	if (!st->sw_mode_en)
 		return 0;
 
-	indio_dev->info = &ad7606_info_os_range_and_debug;
+	indio_dev->info = &ad7606_info_sw_mode;
 
 	/* Scale of 0.076293 is only available in sw mode */
 	/* After reset, in software mode, ±10 V is set by default */
@@ -551,7 +582,29 @@  static int ad7606_sw_mode_setup(struct iio_dev *indio_dev)
 		cs->range = 2;
 	}
 
-	return st->bops->sw_mode_config(indio_dev);
+	ret = st->bops->sw_mode_config(indio_dev);
+	if (ret)
+		return ret;
+
+	for (ch = 0; ch < num_channels; ch++) {
+		struct ad7606_chan_scale *cs = &st->chan_scales[ch];
+		int i;
+
+		cs = &st->chan_scales[ch];
+
+		if (cs->num_scales * 2 > AD760X_MAX_SCALE_SHOW) {
+			dev_err(st->dev, "Driver error: scale range too big");
+			return -ERANGE;
+		}
+
+		/* Generate a scale_avail list for showing to userspace */
+		for (i = 0; i < cs->num_scales; i++) {
+			cs->scale_avail_show[i * 2] = 0;
+			cs->scale_avail_show[i * 2 + 1] = cs->scale_avail[i];
+		}
+	}
+
+	return 0;
 }
 
 int ad7606_probe(struct device *dev, int irq, void __iomem *base_address,
diff --git a/drivers/iio/adc/ad7606.h b/drivers/iio/adc/ad7606.h
index 635407c2acc0..fa175cff256c 100644
--- a/drivers/iio/adc/ad7606.h
+++ b/drivers/iio/adc/ad7606.h
@@ -27,6 +27,29 @@ 
 		},						\
 }
 
+#define AD7606_SW_CHANNEL(num, bits) {				\
+		.type = IIO_VOLTAGE,				\
+		.indexed = 1,					\
+		.channel = num,					\
+		.address = num,					\
+		.info_mask_separate =				\
+			BIT(IIO_CHAN_INFO_RAW) |		\
+			BIT(IIO_CHAN_INFO_SCALE),		\
+		.info_mask_separate_available =			\
+			BIT(IIO_CHAN_INFO_SCALE),		\
+		.info_mask_shared_by_all =			\
+			BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),	\
+		.info_mask_shared_by_all_available =		\
+			BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),	\
+		.scan_index = num,				\
+		.scan_type = {					\
+			.sign = 's',				\
+			.realbits = (bits),			\
+			.storagebits = (bits) > 16 ? 32 : 16,	\
+			.endianness = IIO_CPU,			\
+		},						\
+}
+
 #define AD7605_CHANNEL(num)				\
 	AD760X_CHANNEL(num, BIT(IIO_CHAN_INFO_RAW),	\
 		BIT(IIO_CHAN_INFO_SCALE), 0, 16)
@@ -36,10 +59,6 @@ 
 		BIT(IIO_CHAN_INFO_SCALE),		\
 		BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO), bits)
 
-#define AD7606_SW_CHANNEL(num, bits)	\
-	AD760X_CHANNEL(num, BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE),\
-		0, BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO), bits)
-
 #define AD7616_CHANNEL(num)	AD7606_SW_CHANNEL(num, 16)
 
 /**
@@ -65,11 +84,15 @@  struct ad7606_chip_info {
 /**
  * struct ad7606_chan_scale - channel scale configuration
  * @scale_avail		pointer to the array which stores the available scales
+ * @scale_avail_show	a duplicate of 'scale_avail' which is readily formatted
+ *			such that it can be read via the 'read_avail' hook
  * @num_scales		number of elements stored in the scale_avail array
  * @range		voltage range selection, selects which scale to apply
  */
 struct ad7606_chan_scale {
+#define AD760X_MAX_SCALE_SHOW		(AD760X_MAX_CHANNELS * 2)
 	const unsigned int		*scale_avail;
+	int				scale_avail_show[AD760X_MAX_SCALE_SHOW];
 	unsigned int			num_scales;
 	unsigned int			range;
 };