| Message ID | 20220817105643.95710-3-contact@artur-rojek.eu (mailing list archive) |
|---|---|
| State | Handled Elsewhere |
| Headers | show |
| Series | iio/adc-joystick: buffer data parsing fixes | expand |
On Wed, Aug 17, 2022 at 1:58 PM Artur Rojek <contact@artur-rojek.eu> wrote: > > Introduce a helper function to retrieve an iio_buffer from > iio_cb_buffer. > > This is useful for consumers that need to extract metadata about > the buffer, e.g. get the channel offsets. I'm wondering if we should start using the IIO namespace for new exported symbols.
On Fri, 19 Aug 2022 11:14:04 +0300 Andy Shevchenko <andy.shevchenko@gmail.com> wrote: > On Wed, Aug 17, 2022 at 1:58 PM Artur Rojek <contact@artur-rojek.eu> wrote: > > > > Introduce a helper function to retrieve an iio_buffer from > > iio_cb_buffer. > > > > This is useful for consumers that need to extract metadata about > > the buffer, e.g. get the channel offsets. > > I'm wondering if we should start using the IIO namespace for new > exported symbols. > I'd rather not jump ahead with that because I want to come up with a coherent set of IIO namespaces to separate core / drivers / consumers and platform type code (there's a bit of that left) plus maybe even trigger and buffer implementations. We should probably get on with that though! Jonathan
On Wed, 17 Aug 2022 12:56:41 +0200 Artur Rojek <contact@artur-rojek.eu> wrote: > Introduce a helper function to retrieve an iio_buffer from > iio_cb_buffer. > > This is useful for consumers that need to extract metadata about > the buffer, e.g. get the channel offsets. > > Tested-by: Paul Cercueil <paul@crapouillou.net> > Signed-off-by: Artur Rojek <contact@artur-rojek.eu> Hmm. I'm not keen on breaking this boundary between exposed interface and implementation like this. The intent was always that the consumer knew what it was requesting and had access to all the channel information so should know what the buffer alignment is. In this driver there is a call to devm_iio_channel_get_all() which returns the channels. The buffer offsets can be calculated from that information as the alignement in a buffer a consumer sees is entirely controlled by that information. It might be helpful to provide some helper functions to allow the consumer to establish where particular channels are though. (which will look very like what userspace code has to do as the information available is much the same). Perhaps I'm missing some information that is missing from what is exposed to consumers? Jonathan > --- > drivers/iio/buffer/industrialio-buffer-cb.c | 7 +++++++ > include/linux/iio/consumer.h | 12 ++++++++++++ > 2 files changed, 19 insertions(+) > > diff --git a/drivers/iio/buffer/industrialio-buffer-cb.c b/drivers/iio/buffer/industrialio-buffer-cb.c > index 4c12b7a94af5..47d6e28b4d36 100644 > --- a/drivers/iio/buffer/industrialio-buffer-cb.c > +++ b/drivers/iio/buffer/industrialio-buffer-cb.c > @@ -151,6 +151,13 @@ struct iio_dev > } > EXPORT_SYMBOL_GPL(iio_channel_cb_get_iio_dev); > > +struct iio_buffer > +*iio_channel_cb_get_iio_buffer(struct iio_cb_buffer *cb_buffer) > +{ > + return &cb_buffer->buffer; > +} > +EXPORT_SYMBOL_GPL(iio_channel_cb_get_iio_buffer); > + > MODULE_AUTHOR("Jonathan Cameron <jic23@kernel.org>"); > MODULE_DESCRIPTION("Industrial I/O callback buffer"); > MODULE_LICENSE("GPL"); > diff --git a/include/linux/iio/consumer.h b/include/linux/iio/consumer.h > index 6802596b017c..c28925d5b69c 100644 > --- a/include/linux/iio/consumer.h > +++ b/include/linux/iio/consumer.h > @@ -196,6 +196,18 @@ struct iio_channel > struct iio_dev > *iio_channel_cb_get_iio_dev(const struct iio_cb_buffer *cb_buffer); > > +/** > + * iio_channel_cb_get_iio_buffer() - get access to the underlying buffer. > + * @cb_buffer: The callback buffer from whom we want the buffer > + * information. > + * > + * This function allows one to obtain information about the buffer. > + * The primary aim is to allow drivers that are consuming a buffer to query > + * things like channel offsets in the buffer. > + */ > +struct iio_buffer > +*iio_channel_cb_get_iio_buffer(struct iio_cb_buffer *cb_buffer); > + > /** > * iio_read_channel_raw() - read from a given channel > * @chan: The channel being queried.
diff --git a/drivers/iio/buffer/industrialio-buffer-cb.c b/drivers/iio/buffer/industrialio-buffer-cb.c index 4c12b7a94af5..47d6e28b4d36 100644 --- a/drivers/iio/buffer/industrialio-buffer-cb.c +++ b/drivers/iio/buffer/industrialio-buffer-cb.c @@ -151,6 +151,13 @@ struct iio_dev } EXPORT_SYMBOL_GPL(iio_channel_cb_get_iio_dev); +struct iio_buffer +*iio_channel_cb_get_iio_buffer(struct iio_cb_buffer *cb_buffer) +{ + return &cb_buffer->buffer; +} +EXPORT_SYMBOL_GPL(iio_channel_cb_get_iio_buffer); + MODULE_AUTHOR("Jonathan Cameron <jic23@kernel.org>"); MODULE_DESCRIPTION("Industrial I/O callback buffer"); MODULE_LICENSE("GPL"); diff --git a/include/linux/iio/consumer.h b/include/linux/iio/consumer.h index 6802596b017c..c28925d5b69c 100644 --- a/include/linux/iio/consumer.h +++ b/include/linux/iio/consumer.h @@ -196,6 +196,18 @@ struct iio_channel struct iio_dev *iio_channel_cb_get_iio_dev(const struct iio_cb_buffer *cb_buffer); +/** + * iio_channel_cb_get_iio_buffer() - get access to the underlying buffer. + * @cb_buffer: The callback buffer from whom we want the buffer + * information. + * + * This function allows one to obtain information about the buffer. + * The primary aim is to allow drivers that are consuming a buffer to query + * things like channel offsets in the buffer. + */ +struct iio_buffer +*iio_channel_cb_get_iio_buffer(struct iio_cb_buffer *cb_buffer); + /** * iio_read_channel_raw() - read from a given channel * @chan: The channel being queried.