On Thu, Feb 4, 2021 at 8:16 PM Jonathan Cameron
<jonathan.came...@huawei.com> wrote:
>
> On Mon, 1 Feb 2021 16:51:01 +0200
> Alexandru Ardelean <alexandru.ardel...@analog.com> wrote:
>
> > This change adds a reference to a 'struct iio_buffer' object on the
> > iio_dev_attr object. This way, we can use the created iio_dev_attr objects
> > on per-buffer basis (since they're allocated anyway).
> >
> > A minor downside of this change is that the number of parameters on
> > __iio_add_chan_devattr() grows by 1. This looks like it could do with a bit
> > of a re-think.
>
> Could use a bit of macro magic or static inline to keep the old
> version set of parameter and have __iio_add_chan_devattr_with_buf
> or similar. I'm not sure I'd bother given we don't have that many callers.
If there isn't a strong opinion to add the
__iio_add_chan_devattr_with_buf() version + macro/inline magic, I'd
probably not do it.
In terms of patch-noise, it's not considerably better, and not
necessarily worse.
When I was thinking about the re-think of __iio_add_chan_devattr, I
was thinking of a way to maybe re-architect this.
Maybe, add some {device_}attribute that act as template [at least for
the R/W functions].
This definitely needs some thinking to make it clean and nice.
>
> >
> > Signed-off-by: Alexandru Ardelean <alexandru.ardel...@analog.com>
> > ---
> > drivers/iio/iio_core.h | 2 ++
> > drivers/iio/industrialio-buffer.c | 4 ++++
> > drivers/iio/industrialio-core.c | 6 ++++++
> > drivers/iio/industrialio-event.c | 1 +
> > include/linux/iio/sysfs.h | 3 +++
> > 5 files changed, 16 insertions(+)
> >
> > diff --git a/drivers/iio/iio_core.h b/drivers/iio/iio_core.h
> > index 7d5b179c1fe7..731f5170d5b9 100644
> > --- a/drivers/iio/iio_core.h
> > +++ b/drivers/iio/iio_core.h
> > @@ -12,6 +12,7 @@
> > #include <linux/kernel.h>
> > #include <linux/device.h>
> >
> > +struct iio_buffer;
> > struct iio_chan_spec;
> > struct iio_dev;
> >
> > @@ -43,6 +44,7 @@ int __iio_add_chan_devattr(const char *postfix,
> > u64 mask,
> > enum iio_shared_by shared_by,
> > struct device *dev,
> > + struct iio_buffer *buffer,
> > struct list_head *attr_list);
> > void iio_free_chan_devattr_list(struct list_head *attr_list);
> >
> > diff --git a/drivers/iio/industrialio-buffer.c
> > b/drivers/iio/industrialio-buffer.c
> > index f82decf92b7c..a525e88b302f 100644
> > --- a/drivers/iio/industrialio-buffer.c
> > +++ b/drivers/iio/industrialio-buffer.c
>
> > @@ -447,6 +447,7 @@ static int iio_buffer_add_channel_sysfs(struct iio_dev
> > *indio_dev,
> > 0,
> > IIO_SEPARATE,
> > &indio_dev->dev,
> > + buffer,
> > &buffer->scan_el_dev_attr_list);
> > if (ret)
> > return ret;
> > @@ -458,6 +459,7 @@ static int iio_buffer_add_channel_sysfs(struct iio_dev
> > *indio_dev,
> > 0,
> > 0,
> > &indio_dev->dev,
> > + buffer,
> > &buffer->scan_el_dev_attr_list);
> > if (ret)
> > return ret;
> > @@ -470,6 +472,7 @@ static int iio_buffer_add_channel_sysfs(struct iio_dev
> > *indio_dev,
> > chan->scan_index,
> > 0,
> > &indio_dev->dev,
> > + buffer,
> > &buffer->scan_el_dev_attr_list);
> > else
> > ret = __iio_add_chan_devattr("en",
> > @@ -479,6 +482,7 @@ static int iio_buffer_add_channel_sysfs(struct iio_dev
> > *indio_dev,
> > chan->scan_index,
> > 0,
> > &indio_dev->dev,
> > + buffer,
> > &buffer->scan_el_dev_attr_list);
> > if (ret)
> > return ret;
> > diff --git a/drivers/iio/industrialio-core.c
> > b/drivers/iio/industrialio-core.c
> > index ccd7aaff6d13..c68130885d83 100644
> > --- a/drivers/iio/industrialio-core.c
> > +++ b/drivers/iio/industrialio-core.c
> > @@ -1114,6 +1114,7 @@ int __iio_add_chan_devattr(const char *postfix,
> > u64 mask,
> > enum iio_shared_by shared_by,
> > struct device *dev,
> > + struct iio_buffer *buffer,
> > struct list_head *attr_list)
> > {
> > int ret;
> > @@ -1129,6 +1130,7 @@ int __iio_add_chan_devattr(const char *postfix,
> > goto error_iio_dev_attr_free;
> > iio_attr->c = chan;
> > iio_attr->address = mask;
> > + iio_attr->buffer = buffer;
> > list_for_each_entry(t, attr_list, l)
> > if (strcmp(t->dev_attr.attr.name,
> > iio_attr->dev_attr.attr.name) == 0) {
> > @@ -1165,6 +1167,7 @@ static int iio_device_add_channel_label(struct
> > iio_dev *indio_dev,
> > 0,
> > IIO_SEPARATE,
> > &indio_dev->dev,
> > + NULL,
> > &iio_dev_opaque->channel_attr_list);
> > if (ret < 0)
> > return ret;
> > @@ -1190,6 +1193,7 @@ static int iio_device_add_info_mask_type(struct
> > iio_dev *indio_dev,
> > i,
> > shared_by,
> > &indio_dev->dev,
> > + NULL,
> >
> > &iio_dev_opaque->channel_attr_list);
> > if ((ret == -EBUSY) && (shared_by != IIO_SEPARATE))
> > continue;
> > @@ -1226,6 +1230,7 @@ static int iio_device_add_info_mask_type_avail(struct
> > iio_dev *indio_dev,
> > i,
> > shared_by,
> > &indio_dev->dev,
> > + NULL,
> >
> > &iio_dev_opaque->channel_attr_list);
> > kfree(avail_postfix);
> > if ((ret == -EBUSY) && (shared_by != IIO_SEPARATE))
> > @@ -1322,6 +1327,7 @@ static int iio_device_add_channel_sysfs(struct
> > iio_dev *indio_dev,
> > i,
> > ext_info->shared,
> > &indio_dev->dev,
> > + NULL,
> > &iio_dev_opaque->channel_attr_list);
> > i++;
> > if (ret == -EBUSY && ext_info->shared)
> > diff --git a/drivers/iio/industrialio-event.c
> > b/drivers/iio/industrialio-event.c
> > index ea8947cc21e4..a30e289fc362 100644
> > --- a/drivers/iio/industrialio-event.c
> > +++ b/drivers/iio/industrialio-event.c
> > @@ -385,6 +385,7 @@ static int iio_device_add_event(struct iio_dev
> > *indio_dev,
> >
> > ret = __iio_add_chan_devattr(postfix, chan, show, store,
> > (i << 16) | spec_index, shared_by, &indio_dev->dev,
> > + NULL,
> > &iio_dev_opaque->event_interface->dev_attr_list);
> > kfree(postfix);
> >
> > diff --git a/include/linux/iio/sysfs.h b/include/linux/iio/sysfs.h
> > index b532c875bc24..e51fba66de4b 100644
> > --- a/include/linux/iio/sysfs.h
> > +++ b/include/linux/iio/sysfs.h
> > @@ -9,6 +9,7 @@
> > #ifndef _INDUSTRIAL_IO_SYSFS_H_
> > #define _INDUSTRIAL_IO_SYSFS_H_
> >
> > +struct iio_buffer;
> > struct iio_chan_spec;
> >
> > /**
> > @@ -17,12 +18,14 @@ struct iio_chan_spec;
> > * @address: associated register address
> > * @l: list head for maintaining list of dynamically created
> > attrs
> > * @c: specification for the underlying channel
> > + * @buffer: the IIO buffer to which this attribute belongs to (if any)
> > */
> > struct iio_dev_attr {
> > struct device_attribute dev_attr;
> > u64 address;
> > struct list_head l;
> > struct iio_chan_spec const *c;
> > + struct iio_buffer *buffer;
> > };
> >
> > #define to_iio_dev_attr(_dev_attr) \
>
