Hi Nuno,
On 04.10.2024 14:54, Nuno Sá wrote:
> On Thu, 2024-10-03 at 19:29 +0200, Angelo Dureghello wrote:
> > From: Angelo Dureghello <adureghello@xxxxxxxxxxxx>
> >
> > Extend backend features with new calls needed later on this
> > patchset from axi version of ad3552r.
> >
> > The follwoing calls are added:
> >
> > iio_backend_ddr_enable
> > enable ddr bus transfer
> > iio_backend_ddr_disable
> > disable ddr bus transfer
> > iio_backend_buffer_enable
> > enable buffer
> > iio_backend_buffer_disable
> > disable buffer
> > iio_backend_data_transfer_addr
> > define the target register address where the DAC sample
> > will be written.
> >
> > Signed-off-by: Angelo Dureghello <adureghello@xxxxxxxxxxxx>
> > ---
> > drivers/iio/industrialio-backend.c | 79 ++++++++++++++++++++++++++++++++++++++
> > include/linux/iio/backend.h | 17 ++++++++
> > 2 files changed, 96 insertions(+)
> >
> > diff --git a/drivers/iio/industrialio-backend.c b/drivers/iio/industrialio-
> > backend.c
> > index 20b3b5212da7..d5e0a4da761e 100644
> > --- a/drivers/iio/industrialio-backend.c
> > +++ b/drivers/iio/industrialio-backend.c
> > @@ -718,6 +718,85 @@ static int __devm_iio_backend_get(struct device *dev, struct
> > iio_backend *back)
> > return 0;
> > }
> >
> > +/**
> > + * iio_backend_ddr_enable - Enable interface DDR (Double Data Rate) mode
> > + * @back: Backend device
> > + *
> > + * Enable DDR, data is generated by the IP at each front (raising and falling)
> > + * of the bus clock signal.
> > + *
> > + * RETURNS:
> > + * 0 on success, negative error number on failure.
> > + */
> > +int iio_backend_ddr_enable(struct iio_backend *back)
> > +{
> > + return iio_backend_op_call(back, ddr_enable);
> > +}
> > +EXPORT_SYMBOL_NS_GPL(iio_backend_ddr_enable, IIO_BACKEND);
> > +
> > +/**
> > + * iio_backend_ddr_disable - Disable interface DDR (Double Data Rate) mode
> > + * @back: Backend device
> > + *
> > + * Disable DDR, setting into SDR mode (Single Data Rate).
> > + *
> > + * RETURNS:
> > + * 0 on success, negative error number on failure.
> > + */
> > +int iio_backend_ddr_disable(struct iio_backend *back)
> > +{
> > + return iio_backend_op_call(back, ddr_disable);
> > +}
> > +EXPORT_SYMBOL_NS_GPL(iio_backend_ddr_disable, IIO_BACKEND);
> > +
> > +/**
> > + * iio_backend_dma_stream_enable - Enable iio buffering
> > + * @back: Backend device
> > + *
> > + * Enabling sending the dma data stream over the bus.
> > + * bus interface.
> > + *
> > + * RETURNS:
> > + * 0 on success, negative error number on failure.
> > + */
> > +int iio_backend_dma_stream_enable(struct iio_backend *back)
> > +{
> > + return iio_backend_op_call(back, dma_stream_enable);
> > +}
> > +EXPORT_SYMBOL_NS_GPL(iio_backend_dma_stream_enable, IIO_BACKEND);
> > +
> > +/**
> > + * iio_backend_dma_stream_disable - Disable iio buffering
> > + * @back: Backend device
> > + *
> > + * Disable sending the dma data stream over the bus.
> > + *
> > + * RETURNS:
> > + * 0 on success, negative error number on failure.
> > + */
> > +int iio_backend_dma_stream_disable(struct iio_backend *back)
> > +{
> > + return iio_backend_op_call(back, dma_stream_disable);
> > +}
> > +EXPORT_SYMBOL_NS_GPL(iio_backend_dma_stream_disable, IIO_BACKEND);
> > +
>
> I'm not sure if this is what Jonathan was suggesting... Ate least I don't really
> agree with it. I mean, yes, this is about buffering and to start receiving (or
> sending) a stream of data. But AFAICT, it might have nothing to do with DMA. Same as
> .request_buffer() - It's pretty much always a DMA one but we should not take that for
> granted.
>
> So going back to the RFC [1], you can see I was suggesting something like struct
> iio_buffer_setup_ops. Maybe just add the ones we use for now? So that would
> be.buffer_postenable() and .buffer_predisable(). Like this, it should be obvious the
> intent of the ops.
>
ok, thanks,
so something as :
struct iio_backend_setup_ops {
int (*buffer_postenable)(struct iio_backend *back);
int (*buffer_predisable)(struct iio_backend *back);
};
struct iio_backend_ops {
struct iio_backend_setup_ops setup_ops;
?
> - Nuno Sá
>
>
--
Regards,
Angelo
