Subject: [RFC PATCH v2 3/7] iommu: add new iommu_ops callback for adding an OF device

From: [email-masked] (Will Deacon)
Date: Wed, 10 Sep 2014 12:22:13 +0100

On Wed, Sep 10, 2014 at 12:16:06PM +0100, Marek Szyprowski wrote:
> On 2014-09-02 19:56, Will Deacon wrote:
> > This patch adds a new function to the iommu_ops structure to allow an
> > OF device to be added to a specific IOMMU instance using the recently
> > merged generic devicetree binding for IOMMUs. The callback (of_xlate)
> > takes a struct device representing the master and an of_phandle_args
> > representing the IOMMU and the correspondong IDs for the new master.
> >
> > Signed-off-by: Will Deacon <[email-masked]>
> > ---
> >   include/linux/iommu.h | 5 +++++
> >   1 file changed, 5 insertions(+)
> >
> > diff --git a/include/linux/iommu.h b/include/linux/iommu.h
> > index fdddb14cd8f5..3e766b85daa3 100644
> > --- a/include/linux/iommu.h
> > +++ b/include/linux/iommu.h
> > @@ -21,6 +21,7 @@
> >   
> >   #include <linux/errno.h>
> >   #include <linux/err.h>
> > +#include <linux/of.h>
> >   #include <linux/types.h>
> >   #include <trace/events/iommu.h>
> >   
> > @@ -136,6 +137,10 @@ struct iommu_ops {
> >   	/* Get the numer of window per domain */
> >   	u32 (*domain_get_windows)(struct iommu_domain *domain);
> >   
> > +#ifdef CONFIG_OF_IOMMU
> > +	int (*of_xlate)(struct device *dev, struct of_phandle_args *args);
> 
> If I understand correctly how it is designed to work, then it should be:
> 
> struct iommu_data *(*of_xlate)(struct device *dev, struct 
> of_phandle_args *args);

Yeah, that might be cleaner than the of_iommu_get_data call in
of_dma_configure. I'm currently cooking a v3, so I'll include this change.

Will