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

Alexandru Ardelean
2024-09-07T06:51:00Z

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(-)

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;
};
--
2.46.0