iio: adc: ad7606: rework available attributes for SW channels

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>
Link: https://patch.msgid.link/20240919130444.2100447-6-aardelean@baylibre.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

1 files changed, 28 insertions, 4 deletions

diff --git a/drivers/iio/adc/ad7606.h b/drivers/iio/adc/ad7606.h
index 2b90f52affba..25e84efd15c3 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)
 
 struct ad7606_state;
@@ -71,11 +90,16 @@ 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_SCALES		16
+#define AD760X_MAX_SCALE_SHOW		(AD760X_MAX_SCALES * 2)
 	const unsigned int		*scale_avail;
+	int				scale_avail_show[AD760X_MAX_SCALE_SHOW];
 	unsigned int			num_scales;
 	unsigned int			range;
 };