diff mbox series

[v3,09/12] iio: inkern: Add a helper to query an available minimum raw value

Message ID 20230612122926.107333-10-herve.codina@bootlin.com
State New
Headers
Series Add support for IIO devices in ASoC |

Commit Message

Herve Codina June 12, 2023, 12:29 p.m. UTC 
  A helper, iio_read_max_channel_raw() exists to read the available
maximum raw value of a channel but nothing similar exists to read the
available minimum raw value.

This new helper, iio_read_min_channel_raw(), fills the hole and can be
used for reading the available minimum raw value of a channel.
It is fully based on the existing iio_read_max_channel_raw().

Signed-off-by: Herve Codina <herve.codina@bootlin.com>
---
 drivers/iio/inkern.c         | 63 ++++++++++++++++++++++++++++++++++++
 include/linux/iio/consumer.h | 12 +++++++
 2 files changed, 75 insertions(+)

Comments

Andy Shevchenko June 12, 2023, 2:15 p.m. UTC | #1 
On Mon, Jun 12, 2023 at 3:30 PM Herve Codina <herve.codina@bootlin.com> wrote:
>
> A helper, iio_read_max_channel_raw() exists to read the available
> maximum raw value of a channel but nothing similar exists to read the
> available minimum raw value.
>
> This new helper, iio_read_min_channel_raw(), fills the hole and can be
> used for reading the available minimum raw value of a channel.
> It is fully based on the existing iio_read_max_channel_raw().

Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>

> Signed-off-by: Herve Codina <herve.codina@bootlin.com>
> ---
>  drivers/iio/inkern.c         | 63 ++++++++++++++++++++++++++++++++++++
>  include/linux/iio/consumer.h | 12 +++++++
>  2 files changed, 75 insertions(+)
>
> diff --git a/drivers/iio/inkern.c b/drivers/iio/inkern.c
> index 4331e74191cf..4f383a5ef59f 100644
> --- a/drivers/iio/inkern.c
> +++ b/drivers/iio/inkern.c
> @@ -909,6 +909,69 @@ int iio_read_max_channel_raw(struct iio_channel *chan, int *val)
>  }
>  EXPORT_SYMBOL_GPL(iio_read_max_channel_raw);
>
> +static int iio_channel_read_min(struct iio_channel *chan,
> +                               int *val, int *val2, int *type,
> +                               enum iio_chan_info_enum info)
> +{
> +       const int *vals;
> +       int length;
> +       int ret;
> +
> +       ret = iio_channel_read_avail(chan, &vals, type, &length, info);
> +       if (ret < 0)
> +               return ret;
> +
> +       switch (ret) {
> +       case IIO_AVAIL_RANGE:
> +               switch (*type) {
> +               case IIO_VAL_INT:
> +                       *val = vals[0];
> +                       break;
> +               default:
> +                       *val = vals[0];
> +                       if (val2)
> +                               *val2 = vals[1];
> +               }
> +               return 0;
> +
> +       case IIO_AVAIL_LIST:
> +               if (length <= 0)
> +                       return -EINVAL;
> +               switch (*type) {
> +               case IIO_VAL_INT:
> +                       *val = min_array(vals, length);
> +                       break;
> +               default:
> +                       /* TODO: learn about min for other iio values */
> +                       return -EINVAL;
> +               }
> +               return 0;
> +
> +       default:
> +               return -EINVAL;
> +       }
> +}
> +
> +int iio_read_min_channel_raw(struct iio_channel *chan, int *val)
> +{
> +       struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(chan->indio_dev);
> +       int ret;
> +       int type;
> +
> +       mutex_lock(&iio_dev_opaque->info_exist_lock);
> +       if (!chan->indio_dev->info) {
> +               ret = -ENODEV;
> +               goto err_unlock;
> +       }
> +
> +       ret = iio_channel_read_min(chan, val, NULL, &type, IIO_CHAN_INFO_RAW);
> +err_unlock:
> +       mutex_unlock(&iio_dev_opaque->info_exist_lock);
> +
> +       return ret;
> +}
> +EXPORT_SYMBOL_GPL(iio_read_min_channel_raw);
> +
>  int iio_get_channel_type(struct iio_channel *chan, enum iio_chan_type *type)
>  {
>         struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(chan->indio_dev);
> diff --git a/include/linux/iio/consumer.h b/include/linux/iio/consumer.h
> index f536820b9cf2..e9910b41d48e 100644
> --- a/include/linux/iio/consumer.h
> +++ b/include/linux/iio/consumer.h
> @@ -301,6 +301,18 @@ int iio_write_channel_raw(struct iio_channel *chan, int val);
>   */
>  int iio_read_max_channel_raw(struct iio_channel *chan, int *val);
>
> +/**
> + * iio_read_min_channel_raw() - read minimum available raw value from a given
> + *                             channel, i.e. the minimum possible value.
> + * @chan:              The channel being queried.
> + * @val:               Value read back.
> + *
> + * Note, if standard units are required, raw reads from iio channels
> + * need the offset (default 0) and scale (default 1) to be applied
> + * as (raw + offset) * scale.
> + */
> +int iio_read_min_channel_raw(struct iio_channel *chan, int *val);
> +
>  /**
>   * iio_read_avail_channel_raw() - read available raw values from a given channel
>   * @chan:              The channel being queried.
> --
> 2.40.1
>
diff mbox series

Patch

diff --git a/drivers/iio/inkern.c b/drivers/iio/inkern.c
index 4331e74191cf..4f383a5ef59f 100644
--- a/drivers/iio/inkern.c
+++ b/drivers/iio/inkern.c
@@ -909,6 +909,69 @@  int iio_read_max_channel_raw(struct iio_channel *chan, int *val)
 }
 EXPORT_SYMBOL_GPL(iio_read_max_channel_raw);
 
+static int iio_channel_read_min(struct iio_channel *chan,
+				int *val, int *val2, int *type,
+				enum iio_chan_info_enum info)
+{
+	const int *vals;
+	int length;
+	int ret;
+
+	ret = iio_channel_read_avail(chan, &vals, type, &length, info);
+	if (ret < 0)
+		return ret;
+
+	switch (ret) {
+	case IIO_AVAIL_RANGE:
+		switch (*type) {
+		case IIO_VAL_INT:
+			*val = vals[0];
+			break;
+		default:
+			*val = vals[0];
+			if (val2)
+				*val2 = vals[1];
+		}
+		return 0;
+
+	case IIO_AVAIL_LIST:
+		if (length <= 0)
+			return -EINVAL;
+		switch (*type) {
+		case IIO_VAL_INT:
+			*val = min_array(vals, length);
+			break;
+		default:
+			/* TODO: learn about min for other iio values */
+			return -EINVAL;
+		}
+		return 0;
+
+	default:
+		return -EINVAL;
+	}
+}
+
+int iio_read_min_channel_raw(struct iio_channel *chan, int *val)
+{
+	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(chan->indio_dev);
+	int ret;
+	int type;
+
+	mutex_lock(&iio_dev_opaque->info_exist_lock);
+	if (!chan->indio_dev->info) {
+		ret = -ENODEV;
+		goto err_unlock;
+	}
+
+	ret = iio_channel_read_min(chan, val, NULL, &type, IIO_CHAN_INFO_RAW);
+err_unlock:
+	mutex_unlock(&iio_dev_opaque->info_exist_lock);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(iio_read_min_channel_raw);
+
 int iio_get_channel_type(struct iio_channel *chan, enum iio_chan_type *type)
 {
 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(chan->indio_dev);
diff --git a/include/linux/iio/consumer.h b/include/linux/iio/consumer.h
index f536820b9cf2..e9910b41d48e 100644
--- a/include/linux/iio/consumer.h
+++ b/include/linux/iio/consumer.h
@@ -301,6 +301,18 @@  int iio_write_channel_raw(struct iio_channel *chan, int val);
  */
 int iio_read_max_channel_raw(struct iio_channel *chan, int *val);
 
+/**
+ * iio_read_min_channel_raw() - read minimum available raw value from a given
+ *				channel, i.e. the minimum possible value.
+ * @chan:		The channel being queried.
+ * @val:		Value read back.
+ *
+ * Note, if standard units are required, raw reads from iio channels
+ * need the offset (default 0) and scale (default 1) to be applied
+ * as (raw + offset) * scale.
+ */
+int iio_read_min_channel_raw(struct iio_channel *chan, int *val);
+
 /**
  * iio_read_avail_channel_raw() - read available raw values from a given channel
  * @chan:		The channel being queried.