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

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