Re: [PATCH 1/3] iio: add iio_read_channel_offset() consumer api

From: Peter Meerwald
Date: Thu Aug 16 2012 - 03:42:10 EST



comment below

p.

> This allows the iio consumer to get the offset of the channel.
> The value of offset can be used when calculating the result such
> as 'result = raw * scale + offset'.
>
> Signed-off-by: Milo(Woogyom) Kim <milo.kim@xxxxxx>
> ---
> drivers/iio/inkern.c | 21 +++++++++++++++++++++
> include/linux/iio/consumer.h | 9 +++++++++
> 2 files changed, 30 insertions(+), 0 deletions(-)
>
> diff --git a/drivers/iio/inkern.c b/drivers/iio/inkern.c
> index b5afc2f..bd09245 100644
> --- a/drivers/iio/inkern.c
> +++ b/drivers/iio/inkern.c
> @@ -269,6 +269,27 @@ err_unlock:
> }
> EXPORT_SYMBOL_GPL(iio_read_channel_scale);
>
> +int iio_read_channel_offset(struct iio_channel *chan, int *val)
> +{
> + int val2, ret;
> +
> + mutex_lock(&chan->indio_dev->info_exist_lock);
> + if (chan->indio_dev->info == NULL) {
> + ret = -ENODEV;
> + goto err_unlock;
> + }
> +
> + ret = chan->indio_dev->info->read_raw(chan->indio_dev,
> + chan->channel,
> + val, &val2,
> + IIO_CHAN_INFO_OFFSET);
> +err_unlock:
> + mutex_unlock(&chan->indio_dev->info_exist_lock);
> +
> + return ret;
> +}
> +EXPORT_SYMBOL_GPL(iio_read_channel_offset);
> +
> int iio_get_channel_type(struct iio_channel *chan, enum iio_chan_type *type)
> {
> int ret = 0;
> diff --git a/include/linux/iio/consumer.h b/include/linux/iio/consumer.h
> index e2657e6..d9d69fa 100644
> --- a/include/linux/iio/consumer.h
> +++ b/include/linux/iio/consumer.h
> @@ -93,4 +93,13 @@ int iio_get_channel_type(struct iio_channel *channel,
> int iio_read_channel_scale(struct iio_channel *chan, int *val,
> int *val2);
>
> +/**
> + * iio_read_channel_offset() - read offset from a given channel
> + * @channel: The channel being queried.

the parameter is 'chan', not 'channel'

> + * @val: Offset Value read back.
> + *
> + * Note offset can be used in the consumer when calculating the result
> + * such as 'result = raw * scale + offset'.
> + */
> +int iio_read_channel_offset(struct iio_channel *chan, int *val);
> #endif
>

--

Peter Meerwald
+43-664-2444418 (mobile)
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