The 06/07/2021 12:29, Vinod Koul wrote:
> On 18-05-21, 15:25, Olivier Dautricourt wrote:
> > This driver had no device tree support.
> >
> > - add compatible field "altr,socfpga-msgdma"
> > - define msgdma_of_xlate, with no argument
> > - register dma controller with of_dma_controller_register
> >
> > Reviewed-by: Stefan Roese <sr@xxxxxxx>
> > Signed-off-by: Olivier Dautricourt <olivier.dautricourt@xxxxxxxxxx>
> > ---
> >
> > Notes:
> > Changes in v2:
> > none
> >
> > Changes from v2 to v3:
> > Removed CONFIG_OF #ifdef's and use if (IS_ENABLED(CONFIG_OF))
> > only once.
> >
> > Changes from v3 to v4
> > Reintroduce #ifdef CONFIG_OF for msgdma_match
> > as it produces a unused variable warning
> >
> > Changes from v4 to v5
> > - As per Rob's comments on patch 1/2:
> > change compatible field from altr,msgdma to
> > altr,socfpga-msgdma.
> > - change commit title to fit previous commits naming
> > - As per Vinod's comments:
> > - use dma_get_slave_channel instead of dma_get_any_slave_channel which
> > makes more sense.
> > - remove if (IS_ENABLED(CONFIG_OF)) for of_dma_controller_register
> > as it is taken care by the core
> >
> > drivers/dma/altera-msgdma.c | 26 ++++++++++++++++++++++++++
> > 1 file changed, 26 insertions(+)
> >
> > diff --git a/drivers/dma/altera-msgdma.c b/drivers/dma/altera-msgdma.c
> > index 9a841ce5f0c5..acf0990d73ae 100644
> > --- a/drivers/dma/altera-msgdma.c
> > +++ b/drivers/dma/altera-msgdma.c
> > @@ -19,6 +19,7 @@
> > #include <linux/module.h>
> > #include <linux/platform_device.h>
> > #include <linux/slab.h>
> > +#include <linux/of_dma.h>
> >
> > #include "dmaengine.h"
> >
> > @@ -784,6 +785,14 @@ static int request_and_map(struct platform_device *pdev, const char *name,
> > return 0;
> > }
> >
> > +static struct dma_chan *msgdma_of_xlate(struct of_phandle_args *dma_spec,
> > + struct of_dma *ofdma)
> > +{
> > + struct msgdma_device *d = ofdma->of_dma_data;
> > +
> > + return dma_get_slave_channel(&d->dmachan);
> > +}
>
> Why not use of_dma_simple_xlate() instead?
I guess i could, but i don't think i need to define a filter function,
also there is only one possible channel.
>
> > +
> > /**
> > * msgdma_probe - Driver probe function
> > * @pdev: Pointer to the platform_device structure
> > @@ -888,6 +897,13 @@ static int msgdma_probe(struct platform_device *pdev)
> > if (ret)
> > goto fail;
> >
> > + ret = of_dma_controller_register(pdev->dev.of_node,
> > + msgdma_of_xlate, mdev);
> > + if (ret) {
> > + dev_err(&pdev->dev, "failed to register dma controller");
> > + goto fail;
>
> Should this be treated as an error.. the probe will be invoked on non of
> systems too..
Ok, i'm a bit confused,
in v4 those lines were enclosed with 'if (IS_ENABLED(CONFIG_OF)) { }'
when you said to me that it was already taken care by the core i though
that of_dma_controller_register will return 0 on non-of systems.
Now i can add back IS_ENABLED(CONFIG_OF) or discard the ret value.
>
> --
> ~Vinod
Thanks,
--
Olivier
