Hey Martin,
looks great. I also had in mind that the generic part from Mmio should be
separated as Mmio is already a specialisation of IO access.
So, how do we proceed. Do you want to do the refactoring yourself and I add the
I2c implementation afterwards?
Cheers
Johannes
On Fri, 9 Dec 2016 09:42:04 +0100
Martin Stein <martin.st...@genode-labs.com> wrote:
> Hey Johannes,
>
> I could not get it out of my mind. What do you think of the following
> solution scheme:
>
> ~~~util/io_space.h~~~
>
> template <typename IO>
> class Io_space
> {
> ..
> public:
>
> Io_space(IO &io) ..
>
> template .. struct Register ..;
> template .. struct Register_array ..;
>
> template .. read(..) { .. _io._read(..); .. }
> template .. write(..) { .. _io._write(..); .. }
> ..
> };
>
> ~~~util/mmio.h~~~
>
> class Mmio : public Io_space<Mmio>
> {
> friend class Io_space<Mmio>;
>
> private:
>
> template .. _read(..) { .. }
> template .. _write(..) { .. }
>
> public:
>
> Mmio_b(addr_t base) : Io_space<Mmio_accessor>(*this) ..
> };
>
> ~~~i2c_io.h~~~
>
> class I2c_io : public Io_space<I2c_io> { .. };
>
> ~~~~~~
>
> This would keep the back-end hidden and enable diversification.
>
> Cheers,
> Martin
>
> Am 08.12.2016 um 15:37 schrieb Martin Stein:
> > Hi Johannes,
> >
> > We actually had an internal discussion about such an approach. As far as
> > I remember, it was in the context of the Zynq drivers. I absolutely like
> > the idea of using the Mmio framework with different back-ends. I think
> > you would have to exchange merely the two raw-access methods of the
> > framework:
> >
> > ! template <typename _ACCESS_T>
> > ! void Mmio::_write(off_t const, _ACCESS_T const)'
> > !
> > ! template <typename _ACCESS_T>
> > ! _ACCESS_T Mmio::_read(off_t const) const
> >
> > The read<>() and write<>() methods you mention should not contain any
> > code that depends on the way of accessing registers but only the bit and
> > offset logic that could be reused.
> >
> > I'm curious about the outcome of your idea and help willingly if you
> > have further questions.
> >
> > Cheers,
> > Martin
> >
> > Am 07.12.2016 um 18:26 schrieb Johannes Schlatow:
> >> Hi,
> >>
> >> I really like Genode's Register API as it makes accessing memory mapped
> >> hardware registers quite clean and simple.
> >>
> >> However, I recently encountered the need to access a rather complex I2C
> >> slave device. The I2C controller itself is accessible via MMIO. Yet, the
> >> slave device itself has a notion of registers. Basically, you first send
> >> the register address to the I2C slave and, in a second transaction, you
> >> can read/write the register's value.
> >>
> >> Being used to the clean appearance of MMIO in Genode, I was wondering
> >> whether the access to I2C slave registers could be wrapped in a similar
> >> way. My intuition is that it might simply suffice to inherit from the Mmio
> >> class and modify the write<>() and read<>() functions but haven't checked
> >> the code in detail. Any suggestions/ideas?
> >>
> >> Cheers
> >> Johannes
> >>
> >> ------------------------------------------------------------------------------
> >> Developer Access Program for Intel Xeon Phi Processors
> >> Access to Intel Xeon Phi processor-based developer platforms.
> >> With one year of Intel Parallel Studio XE.
> >> Training and support from Colfax.
> >> Order your platform today.http://sdm.link/xeonphi
> >> _______________________________________________
> >> genode-main mailing list
> >> genode-main@lists.sourceforge.net
> >> https://lists.sourceforge.net/lists/listinfo/genode-main
> >>
> >
> > ------------------------------------------------------------------------------
> > Developer Access Program for Intel Xeon Phi Processors
> > Access to Intel Xeon Phi processor-based developer platforms.
> > With one year of Intel Parallel Studio XE.
> > Training and support from Colfax.
> > Order your platform today.http://sdm.link/xeonphi
> > _______________________________________________
> > genode-main mailing list
> > genode-main@lists.sourceforge.net
> > https://lists.sourceforge.net/lists/listinfo/genode-main
> >
>
>
> ------------------------------------------------------------------------------
> Developer Access Program for Intel Xeon Phi Processors
> Access to Intel Xeon Phi processor-based developer platforms.
> With one year of Intel Parallel Studio XE.
> Training and support from Colfax.
> Order your platform today.http://sdm.link/xeonphi
> _______________________________________________
> genode-main mailing list
> genode-main@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/genode-main
--
Johannes Schlatow, M.Sc.
IDA, Institute of Computer and Network Engineering
Technische Universität Braunschweig
Hans-Sommer-Str. 66
38106 Braunschweig - Germany
Phone +49 531 391 - 9668
www.ida.ing.tu-bs.de
schla...@ida.ing.tu-bs.de
------------------------------------------------------------------------------
Developer Access Program for Intel Xeon Phi Processors
Access to Intel Xeon Phi processor-based developer platforms.
With one year of Intel Parallel Studio XE.
Training and support from Colfax.
Order your platform today.http://sdm.link/xeonphi
_______________________________________________
genode-main mailing list
genode-main@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/genode-main
