| Message ID | 20240704155338.2387858-2-olivier.moysan@foss.st.com (mailing list archive) |
|---|---|
| State | Changes Requested |
| Headers | show |
| Series | iio: adc: dfsdm: add scaling support | expand |
On Thu, 2024-07-04 at 17:53 +0200, Olivier Moysan wrote: > Add iio_backend_read_scale() and iio_backend_read_offset() services > to read channel scale and offset from an IIO backbend device. > > Also add a read_raw callback which replicates the read_raw callback of > the IIO framework, and is intended to request miscellaneous channel > attributes from the backend device. > Both scale and offset helpers use this callback. > > Signed-off-by: Olivier Moysan <olivier.moysan@foss.st.com> > Reviewed-by: Nuno Sa <nuno.sa@analog.com> > --- > drivers/iio/industrialio-backend.c | 34 ++++++++++++++++++++++++++++++ > include/linux/iio/backend.h | 9 +++++++- > 2 files changed, 42 insertions(+), 1 deletion(-) > > diff --git a/drivers/iio/industrialio-backend.c b/drivers/iio/industrialio- > backend.c > index efe05be284b6..4e0ff6e6e9d4 100644 > --- a/drivers/iio/industrialio-backend.c > +++ b/drivers/iio/industrialio-backend.c > @@ -357,6 +357,40 @@ int devm_iio_backend_request_buffer(struct device *dev, > } > EXPORT_SYMBOL_NS_GPL(devm_iio_backend_request_buffer, IIO_BACKEND); > > +/** > + * iio_backend_read_scale - Request channel scale from the IIO backend. > + * @back: Backend device > + * @chan: IIO channel reference > + * @scale: returned scale value > + * > + * RETURNS: > + * 0 on success, negative error number on failure. > + */ > +int iio_backend_read_scale(struct iio_backend *back, > + struct iio_chan_spec const *chan, int *scale) > +{ > + return iio_backend_op_call(back, read_raw, chan, scale, NULL, > + IIO_CHAN_INFO_SCALE); > +} > +EXPORT_SYMBOL_NS_GPL(iio_backend_read_scale, IIO_BACKEND); > + > +/** > + * iio_backend_read_offset - Request channel offset from the IIO backend. > + * @back: Backend device > + * @chan: IIO channel reference > + * @offset: returned offset value > + * > + * RETURNS: > + * 0 on success, negative error number on failure. > + */ > +int iio_backend_read_offset(struct iio_backend *back, > + struct iio_chan_spec const *chan, int *offset) > +{ > + return iio_backend_op_call(back, read_raw, chan, offset, NULL, > + IIO_CHAN_INFO_OFFSET); > +} > +EXPORT_SYMBOL_NS_GPL(iio_backend_read_offset, IIO_BACKEND); > + Hi Olivier, Not exactly what I had in mind :). My thinking was to have: int iio_backend_read_raw(struct iio_backend *back, struct iio_chan_spec const *chan, int *val, int *val2, long mask) { return iio_backend_op_call(back, read_raw, chan, val, val2, mask); } EXPORT_SYMBOL_NS_GPL(iio_backend_read_raw, IIO_BACKEND); Then, on backend.h static inline int iio_backend_read_scale(struct iio_backend *back, struct iio_chan_spec const *chan, int *val, int val2) { return iio_backend_read_raw(..., IIO_CHAN_INFO_SCALE); } Advantage is that we only need to export one symbol from the framework. But the most important piece I don't really agree in the patch is assuming NULL for val2 (even more in scale where often we use both vals). So I think it already makes sense to expose the API with two int's even if you don't need them for your usecase. - Nuno Sá
diff --git a/drivers/iio/industrialio-backend.c b/drivers/iio/industrialio-backend.c index efe05be284b6..4e0ff6e6e9d4 100644 --- a/drivers/iio/industrialio-backend.c +++ b/drivers/iio/industrialio-backend.c @@ -357,6 +357,40 @@ int devm_iio_backend_request_buffer(struct device *dev, } EXPORT_SYMBOL_NS_GPL(devm_iio_backend_request_buffer, IIO_BACKEND); +/** + * iio_backend_read_scale - Request channel scale from the IIO backend. + * @back: Backend device + * @chan: IIO channel reference + * @scale: returned scale value + * + * RETURNS: + * 0 on success, negative error number on failure. + */ +int iio_backend_read_scale(struct iio_backend *back, + struct iio_chan_spec const *chan, int *scale) +{ + return iio_backend_op_call(back, read_raw, chan, scale, NULL, + IIO_CHAN_INFO_SCALE); +} +EXPORT_SYMBOL_NS_GPL(iio_backend_read_scale, IIO_BACKEND); + +/** + * iio_backend_read_offset - Request channel offset from the IIO backend. + * @back: Backend device + * @chan: IIO channel reference + * @offset: returned offset value + * + * RETURNS: + * 0 on success, negative error number on failure. + */ +int iio_backend_read_offset(struct iio_backend *back, + struct iio_chan_spec const *chan, int *offset) +{ + return iio_backend_op_call(back, read_raw, chan, offset, NULL, + IIO_CHAN_INFO_OFFSET); +} +EXPORT_SYMBOL_NS_GPL(iio_backend_read_offset, IIO_BACKEND); + static struct iio_backend *iio_backend_from_indio_dev_parent(const struct device *dev) { struct iio_backend *back = ERR_PTR(-ENODEV), *iter; diff --git a/include/linux/iio/backend.h b/include/linux/iio/backend.h index 8099759d7242..2d80e3fa58ce 100644 --- a/include/linux/iio/backend.h +++ b/include/linux/iio/backend.h @@ -81,6 +81,7 @@ enum iio_backend_sample_trigger { * @extend_chan_spec: Extend an IIO channel. * @ext_info_set: Extended info setter. * @ext_info_get: Extended info getter. + * @read_raw: Read a channel attribute from a backend device **/ struct iio_backend_ops { int (*enable)(struct iio_backend *back); @@ -113,6 +114,9 @@ struct iio_backend_ops { const char *buf, size_t len); int (*ext_info_get)(struct iio_backend *back, uintptr_t private, const struct iio_chan_spec *chan, char *buf); + int (*read_raw)(struct iio_backend *back, + struct iio_chan_spec const *chan, int *val, int *val2, + long mask); }; int iio_backend_chan_enable(struct iio_backend *back, unsigned int chan); @@ -141,7 +145,10 @@ ssize_t iio_backend_ext_info_set(struct iio_dev *indio_dev, uintptr_t private, const char *buf, size_t len); ssize_t iio_backend_ext_info_get(struct iio_dev *indio_dev, uintptr_t private, const struct iio_chan_spec *chan, char *buf); - +int iio_backend_read_scale(struct iio_backend *back, + struct iio_chan_spec const *chan, int *scale); +int iio_backend_read_offset(struct iio_backend *back, + struct iio_chan_spec const *chan, int *offset); int iio_backend_extend_chan_spec(struct iio_dev *indio_dev, struct iio_backend *back, struct iio_chan_spec *chan);