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>

diff --git a/drivers/iio/adc/ad7606.c b/drivers/iio/adc/ad7606.c
index 94a254c..b909ee1 100644 (file)
--- a/drivers/iio/adc/ad7606.c
+++ b/drivers/iio/adc/ad7606.c
@@ -512,6 +512,37 @@ 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,
@@ -529,11 +560,11 @@ 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,
 };
 
@@ -564,7 +595,7 @@ 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;
 
        return st->bops->sw_mode_config(indio_dev);
 }
@@ -576,9 +607,24 @@ static int ad7606_chan_scales_setup(struct iio_dev *indio_dev)
        int ch, ret;
 
        for (ch = 0; ch < num_channels; ch++) {
+               struct ad7606_chan_scale *cs;
+               int i;
+
                ret = st->chip_info->scale_setup_cb(st, ch);
                if (ret)
                        return ret;
+
+               cs = &st->chan_scales[ch];
+
+               if (cs->num_scales * 2 > AD760X_MAX_SCALE_SHOW)
+                       return dev_err_probe(st->dev, -ERANGE,
+                                       "Driver error: scale range too big");
+
+               /* 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;

diff --git a/drivers/iio/adc/ad7606.h b/drivers/iio/adc/ad7606.h
index 2b90f52..25e84ef 100644 (file)
--- 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;
 };

diff --git a/drivers/iio/adc/ad7606_spi. b/drivers/iio/adc/ad7606_spi.
new file mode 100644 (file)
index 0000000..e69de29