On Thu, Sep 17, 2015 at 12:01 AM, Jani Nikula <jani.nikula@xxxxxxxxxxxxxxx> wrote: > On Wed, 16 Sep 2015, Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> wrote: >> On Wed, Sep 16, 2015 at 01:09:54PM -0700, Daniel Vetter wrote: >>> On Tue, Sep 15, 2015 at 10:03:09AM -0700, Rafael Antognolli wrote: >>> > On Tue, Sep 15, 2015 at 07:46:55PM +0300, Ville Syrjälä wrote: >>> > > On Tue, Sep 15, 2015 at 07:41:06PM +0300, Ville Syrjälä wrote: >>> > > > On Tue, Sep 15, 2015 at 09:34:15AM -0700, Rafael Antognolli wrote: >>> > > > > On Tue, Sep 15, 2015 at 10:35:19AM +0300, Ville Syrjälä wrote: >>> > > > > > On Mon, Sep 14, 2015 at 04:12:29PM -0700, Rafael Antognolli wrote: >>> > > > > > > This is a tentative implementation of a module that allows reading/writing >>> > > > > > > arbitrary dpcd registers, following the suggestion from Daniel Vetter. It >>> > > > > > > assumes the drm aux helpers were used by the driver. >>> > > > > > > >>> > > > > > > I tried to follow the i2c-dev implementation as close as possible, but the only >>> > > > > > > operations that are provided on the dev node are two different ioctl's, one for >>> > > > > > > reading a register and another one for writing it. >>> > > > > > >>> > > > > > Why would you use ioctls instead of normal read/write syscalls? >>> > > > > > >>> > > > > >>> > > > > For writing, that should work fine, I can easily change that if you >>> > > > > prefer. >>> > > > > >>> > > > > For reading, one has to first tell which register address is going to be >>> > > > > read. >>> > > > >>> > > > seek() >>> > > >>> > > Sorry typo. Make that lseek(). >>> > > >>> > Oh, nice, I'll update the patch with this and remove the notifier stuff, >>> > thanks! >>> >>> Well there's also other modes like i2c over aux, and that would be easier >>> to support with an ioctl in a uniform way. So not sure how much value >>> there is in reusing read/write for i2c ... >> >> We already have i2c-dev for i2c. So not sure what you're after here. > > Yeah, definitely don't reinvent the wheel for this. Of course I didn't mean to reinvent the i2c-dev wheel, but just expose the underlying low-level dp aux ops to do i2c transaction - that might be useful for hacking around to figure out some of the recent i2c changes we've done. Otoh we could add such a raw mode later on as an ioctl, for plain dpcd reads/writes read/write/lseek seems indeed a good fit. -Daniel -- Daniel Vetter Software Engineer, Intel Corporation +41 (0) 79 365 57 48 - http://blog.ffwll.ch _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/dri-devel
