On Wed, 16 Sep 2020 16:21:15 +0300 Cristian Pop <[email protected]> wrote:
> If a label is defined in the device tree for this channel add that > to the channel specific attributes. This is useful for userspace to > be able to identify an individual channel. > > Signed-off-by: Cristian Pop <[email protected]> Hi Cristian. I (and lore.kernel.org) only received patch 1 so guess docs and example were in patches 2 and 3? Something odd is perhaps going on with Analog's email vs vger as there was only a partial set of Nuno's series last night as well so I couldn't pick it up with b4. This patch looks good to me. Thanks for your hard work on this. Given timing it may slip into the next cycle. Jonathan > --- > Change in V4: > - Check for callback before generating file system for label > - Add documentation in: Documentation/ABI/testing/sysfs-bus-iio > - Add example of usage for channel label attribute > drivers/iio/industrialio-core.c | 41 +++++++++++++++++++++++++++++++++ > include/linux/iio/iio.h | 6 +++++ > 2 files changed, 47 insertions(+) > > diff --git a/drivers/iio/industrialio-core.c b/drivers/iio/industrialio-core.c > index 1527f01a44f1..49868e080840 100644 > --- a/drivers/iio/industrialio-core.c > +++ b/drivers/iio/industrialio-core.c > @@ -643,6 +643,21 @@ ssize_t iio_format_value(char *buf, unsigned int type, > int size, int *vals) > } > EXPORT_SYMBOL_GPL(iio_format_value); > > +static ssize_t iio_read_channel_label(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_label) > + return indio_dev->info->read_label(indio_dev, > + this_attr->c, > + buf); > + else > + return -EINVAL; > +} > + > static ssize_t iio_read_channel_info(struct device *dev, > struct device_attribute *attr, > char *buf) > @@ -1111,6 +1126,25 @@ int __iio_add_chan_devattr(const char *postfix, > return ret; > } > > +static int iio_device_add_channel_label(struct iio_dev *indio_dev, > + struct iio_chan_spec const *chan) > +{ > + int ret; > + > + ret = __iio_add_chan_devattr("label", > + chan, > + &iio_read_channel_label, > + NULL, > + 0, > + IIO_SEPARATE, > + &indio_dev->dev, > + &indio_dev->channel_attr_list); > + if (ret < 0) > + return ret; > + > + return 1; > +} > + > static int iio_device_add_info_mask_type(struct iio_dev *indio_dev, > struct iio_chan_spec const *chan, > enum iio_shared_by shared_by, > @@ -1241,6 +1275,13 @@ static int iio_device_add_channel_sysfs(struct iio_dev > *indio_dev, > return ret; > attrcount += ret; > > + if (indio_dev->info->read_label) { > + ret = iio_device_add_channel_label(indio_dev, chan); > + if (ret < 0) > + return ret; > + attrcount += ret; > + } > + > if (chan->ext_info) { > unsigned int i = 0; > for (ext_info = chan->ext_info; ext_info->name; ext_info++) { > diff --git a/include/linux/iio/iio.h b/include/linux/iio/iio.h > index a1be82e74c93..58b151f5321d 100644 > --- a/include/linux/iio/iio.h > +++ b/include/linux/iio/iio.h > @@ -362,6 +362,8 @@ struct iio_trigger; /* forward declaration */ > * and max. For lists, all possible values are enumerated. > * @write_raw: function to write a value to the device. > * Parameters are the same as for read_raw. > + * @read_label: function to request label name for a specified > label, > + * for better channel identification. > * @write_raw_get_fmt: callback function to query the expected > * format/precision. If not set by the driver, write_raw > * returns IIO_VAL_INT_PLUS_MICRO. > @@ -420,6 +422,10 @@ struct iio_info { > int val2, > long mask); > > + int (*read_label)(struct iio_dev *indio_dev, > + struct iio_chan_spec const *chan, > + char *label); > + > int (*write_raw_get_fmt)(struct iio_dev *indio_dev, > struct iio_chan_spec const *chan, > long mask);
