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 <[email protected]>
Reviewed-by: Andy Shevchenko <[email protected]>
---
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 19ddd77adb11..7a1f6713318a 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
On Thu, 15 Jun 2023 17:26:28 +0200
Herve Codina <[email protected]> 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().
>
> Signed-off-by: Herve Codina <[email protected]>
> Reviewed-by: Andy Shevchenko <[email protected]>
LGTM
Acked-by: Jonathan Cameron <[email protected]>
> ---
> 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 19ddd77adb11..7a1f6713318a 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.