On Thu, 5 Oct 2023 19:50:29 -0500
David Lechner <dlechner@xxxxxxxxxxxx> wrote:
> This adds a new optional field to struct iio_info to allow drivers to
> specify a label for the event. This is useful for cases where there are
> many events or the event attribute name is not descriptive enough or
> where an event doesn't have any other attributes.
>
> The implementation is based on the existing label support for channels.
> So either all events of a device have a label attribute or none do.
>
> Signed-off-by: David Lechner <dlechner@xxxxxxxxxxxx>
Was going to moan about lack of docs, but I see they are in later patches.
Ok. General feature is fine. Applied.
Jonathan
> ---
>
> v4 changes: New patch in v4.
>
> drivers/iio/industrialio-event.c | 55 ++++++++++++++++++++++++++++++++++++++++
> include/linux/iio/iio.h | 8 ++++++
> 2 files changed, 63 insertions(+)
>
> diff --git a/drivers/iio/industrialio-event.c b/drivers/iio/industrialio-event.c
> index 19f7a91157ee..910c1f14abd5 100644
> --- a/drivers/iio/industrialio-event.c
> +++ b/drivers/iio/industrialio-event.c
> @@ -355,6 +355,21 @@ static ssize_t iio_ev_value_store(struct device *dev,
> return len;
> }
>
> +static ssize_t iio_ev_label_show(struct device *dev,
> + struct device_attribute *attr,
> + char *buf)
> +{
> + struct iio_dev *indio_dev = dev_to_iio_dev(dev);
> + struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
> +
> + if (indio_dev->info->read_event_label)
> + return indio_dev->info->read_event_label(indio_dev,
> + this_attr->c, iio_ev_attr_type(this_attr),
> + iio_ev_attr_dir(this_attr), buf);
> +
> + return -EINVAL;
> +}
> +
> static int iio_device_add_event(struct iio_dev *indio_dev,
> const struct iio_chan_spec *chan, unsigned int spec_index,
> enum iio_event_type type, enum iio_event_direction dir,
> @@ -411,6 +426,41 @@ static int iio_device_add_event(struct iio_dev *indio_dev,
> return attrcount;
> }
>
> +static int iio_device_add_event_label(struct iio_dev *indio_dev,
> + const struct iio_chan_spec *chan,
> + unsigned int spec_index,
> + enum iio_event_type type,
> + enum iio_event_direction dir)
> +{
> + struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
> + char *postfix;
> + int ret;
> +
> + if (!indio_dev->info->read_event_label)
> + return 0;
> +
> + if (dir != IIO_EV_DIR_NONE)
> + postfix = kasprintf(GFP_KERNEL, "%s_%s_label",
> + iio_ev_type_text[type],
> + iio_ev_dir_text[dir]);
> + else
> + postfix = kasprintf(GFP_KERNEL, "%s_label",
> + iio_ev_type_text[type]);
> + if (postfix == NULL)
> + return -ENOMEM;
> +
> + ret = __iio_add_chan_devattr(postfix, chan, &iio_ev_label_show, NULL,
> + spec_index, IIO_SEPARATE, &indio_dev->dev, NULL,
> + &iio_dev_opaque->event_interface->dev_attr_list);
> +
> + kfree(postfix);
> +
> + if (ret < 0)
> + return ret;
> +
> + return 1;
> +}
> +
> static int iio_device_add_event_sysfs(struct iio_dev *indio_dev,
> struct iio_chan_spec const *chan)
> {
> @@ -448,6 +498,11 @@ static int iio_device_add_event_sysfs(struct iio_dev *indio_dev,
> if (ret < 0)
> return ret;
> attrcount += ret;
> +
> + ret = iio_device_add_event_label(indio_dev, chan, i, type, dir);
> + if (ret < 0)
> + return ret;
> + attrcount += ret;
> }
> ret = attrcount;
> return ret;
> diff --git a/include/linux/iio/iio.h b/include/linux/iio/iio.h
> index 7bfa1b9bc8a2..d0ce3b71106a 100644
> --- a/include/linux/iio/iio.h
> +++ b/include/linux/iio/iio.h
> @@ -427,6 +427,8 @@ struct iio_trigger; /* forward declaration */
> * @write_event_config: set if the event is enabled.
> * @read_event_value: read a configuration value associated with the event.
> * @write_event_value: write a configuration value for the event.
> + * @read_event_label: function to request label name for a specified label,
> + * for better event identification.
> * @validate_trigger: function to validate the trigger when the
> * current trigger gets changed.
> * @update_scan_mode: function to configure device and scan buffer when
> @@ -511,6 +513,12 @@ struct iio_info {
> enum iio_event_direction dir,
> enum iio_event_info info, int val, int val2);
>
> + int (*read_event_label)(struct iio_dev *indio_dev,
> + struct iio_chan_spec const *chan,
> + enum iio_event_type type,
> + enum iio_event_direction dir,
> + char *label);
> +
> int (*validate_trigger)(struct iio_dev *indio_dev,
> struct iio_trigger *trig);
> int (*update_scan_mode)(struct iio_dev *indio_dev,
>
