Re: [PATCH v10 05/18] OMAP2,3 DSS2 Change driver name to omap_display

Tomi Valkeinen
2011-02-28T12:10:34Z

On Mon, 2011-02-28 at 05:36 -0600, Cousson, Benoit wrote:
> Hi Tomi,
>
> On 2/28/2011 8:19 AM, Valkeinen, Tomi wrote:
> > On Mon, 2011-02-28 at 01:09 -0600, Taneja, Archit wrote:
> >> Hi,
> >>
> >> On Monday 28 February 2011 12:23 PM, Valkeinen, Tomi wrote:
> >>> On Thu, 2011-02-24 at 03:27 -0600, Tomi Valkeinen wrote:
> >>>> Hi,
> >>>>
> >>>> On Mon, 2011-01-24 at 11:51 +0530, ext Sumit Semwal wrote:
> >>>>> From: Senthilvadivu Guruswamy<svadivu@ti.com>
> >>>>>
> >>>>> Change the driver name from omapdss to omap_display as the driver takes care of
> >>>>> the display devices ie number of panels, type of panels available in the
> >>>>> platform. Change the device name in the board files and 2420,2430,3xxx clock
> >>>>> files from omapdss to omap_display to match the driver name.
> >>>>
> >>>> I just realized that changing the driver name will break all scripts and
> >>>> applications using omapdss sysfs files.
> >>>>
> >>>> How does this sound:
> >>>>
> >>>> Let's leave the omapdss device name as it is. It represents a "super"
> >>>> device, containing the dss sysfs files and upper level dss management.
>
> This is the case for all the drivers migrated to omap_device anyway due
> to the change in the top level hierarchy. Everything is below
> platform/omap now.

The HW module drivers are under platform/omap/, but omapdss is in
platform/. Do you mean that omapdss should also be under platform/omap/?

The reason I'm unwilling to change omapdss name, or location, is that
omapdss directory contains lots of DSS configuration files, used by
scripts and programs.

> That's why we are using that opportunity to clean and provide a
> consistent naming for all devices.
>
> >>>> Name the HW module platform drivers as: omapdss_dss, omapdss_venc,
> >>>> omapdss_dispc, etc. This would indicate them to be clearly parts of DSS,
> >>>> and would also prevent any possible name conflict if there would happen
> >>>> to be a, say, "dsi" block in some other HW component.
>
> Cannot you use a device hierarchy then to do that?
> omap_dss/core
> omap_dss/dsi
> omap_dss/venc
>
> This is moreover the way the HW is done.

Hmm, how would that work? The devices are platform devices, and they
have a unique global name, which is used to match the driver for the
device.

>
> >>> Any comments on this?
> >>
> >> I also think we need to stick to the older name, "omapdss_dss" sounds a
> >> bit confusing, and I think one of the previous versions had something
> >> like "dss_dss" in it and it wasn't approved. Does something like
> >> "omapdss_core" or "omapdss_dss_core" make sense, or is it more misleading?
> >
> > It is confusing, but so is the hardware naming =). There is a DSS module
> > inside the omap display subsystem. That's why I would like to name it
> > "dss", not "core", so it's clear it refers to this DSS module.
> >
> > "dss_dss" looks a bit silly, but I think "omapdss_dss" is slightly
> > better in the sense that it doesn't repeat the same "dss", and there is
> > an "omapdss" device, which acts like "manager" for these module devices.
> > But yes, I wouldn't call it perfect either.
> >
> > "omapdss_dss_core" is one option. But then again, TRM doesn't speak of
> > "core".
>
> We should not maintain silly names just because they are in the TRM, we
> should just fix the TRM. This is exactly what we are going to do for
> most HW names we introduced in OMAP4.
>
> So if we all agree that this name will avoid confusion and is much
> better than the current one, we can change it right now with a comment
> to explain the change and give the pointer to the current TRM naming.

True. But I don't think there's a huge difference with omapdss_dss or
omapdss_core.

The name is used in only a few places inside the kernel, and never from
userspace, so we can change that also later.

The main issue I had was changing the omapdss device name, which would
break the userspace.

Tomi