From: Philipp Rossak <embed3d@gmail.com>
To: Maxime Ripard <maxime@cerno.tech>
Cc: "H. Nikolaus Schaller" <hns@goldelico.com>,
"David Airlie" <airlied@linux.ie>,
"Daniel Vetter" <daniel@ffwll.ch>,
"Rob Herring" <robh+dt@kernel.org>,
"Mark Rutland" <mark.rutland@arm.com>,
"Benoît Cousson" <bcousson@baylibre.com>,
"Tony Lindgren" <tony@atomide.com>,
"Paul Cercueil" <paul@crapouillou.net>,
"Ralf Baechle" <ralf@linux-mips.org>,
"Paul Burton" <paulburton@kernel.org>,
"James Hogan" <jhogan@kernel.org>,
"Kukjin Kim" <kgene@kernel.org>,
"Krzysztof Kozlowski" <krzk@kernel.org>,
"Chen-Yu Tsai" <wens@csie.org>,
"Thomas Bogendoerfer" <tsbogend@alpha.franken.de>,
"open list:DRM PANEL DRIVERS" <dri-devel@lists.freedesktop.org>,
"open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS"
<devicetree@vger.kernel.org>,
"Linux Kernel Mailing List" <linux-kernel@vger.kernel.org>,
linux-omap <linux-omap@vger.kernel.org>,
"OpenPVRSGX Linux Driver Group" <openpvrsgx-devgroup@letux.org>,
"Discussions about the Letux Kernel"
<letux-kernel@openphoenux.org>,
kernel@pyra-handheld.com, linux-mips@vger.kernel.org,
arm-soc <linux-arm-kernel@lists.infradead.org>,
linux-samsung-soc@vger.kernel.org
Subject: Re: [PATCH v6 00/12] ARM/MIPS: DTS: add child nodes describing the PVRSGX GPU present in some OMAP SoC and JZ4780 (and many more)
Date: Tue, 21 Apr 2020 18:42:17 +0200 [thread overview]
Message-ID: <5749af21-e707-c998-c83b-50c48867c9e8@gmail.com> (raw)
In-Reply-To: <20200421112129.zjmkmzo3aftksgka@gilmour.lan>
Hi,
On 21.04.20 13:21, Maxime Ripard wrote:
> Hi,
>
> On Tue, Apr 21, 2020 at 11:57:33AM +0200, Philipp Rossak wrote:
>> On 20.04.20 09:38, Maxime Ripard wrote:
>>> Hi,
>>>
>>> On Fri, Apr 17, 2020 at 02:09:06PM +0200, Philipp Rossak wrote:
>>>>>> I'm a bit skeptical on that one since it doesn't even list the
>>>>>> interrupts connected to the GPU that the binding mandates.
>>>>>
>>>>> I think he left it out for a future update.
>>>>> But best he comments himself.
>>>>
>>>> I'm currently working on those bindings. They are now 90% done, but they are
>>>> not finished till now. Currently there is some mainline support missing to
>>>> add the full binding. The A83T and also the A31/A31s have a GPU Power Off
>>>> Gating Register in the R_PRCM module, that is not supported right now in
>>>> Mainline. The Register need to be written when the GPU is powered on and
>>>> off.
>>>>
>>>> @Maxime: I totally agree on your point that a demo needs to be provided
>>>> before the related DTS patches should be provided. That's the reason why I
>>>> added the gpu placeholder patches.
>>>> Do you have an idea how a driver for the R_PRCM stuff can look like? I'm not
>>>> that experienced with the clock driver framework.
>>>
>>> It looks like a power-domain to me, so you'd rather plug that into the genpd
>>> framework.
>>
>> I had a look on genpd and I'm not really sure if that fits.
>>
>> It is basically some bit that verify that the clocks should be enabled or
>> disabled.
>
> No, it can do much more than that. It's a framework to control the SoCs power
> domains, so clocks might be a part of it, but most of the time it's going to be
> about powering up a particular device.
>
So I think I've found now the right piece of documentation and a driver
that implements something similar [1].
So I will write a similar driver like linked above that only sets the
right bits for A83T and A31/A31s.
Do you think this is the right approach?
>> I think this is better placed somewhere in the clocking framework.
>> I see there more similarities to the gating stuff.
>> Do you think it is suitable to implement it like the clock gating?
>
> I'm really not sure what makes you think that this should be modelled as a
> clock?
>
Looks like I looked in the wrong place and got some information that are
not suitable for this.
>>>> The big question is right now how to proceed with the A83T and A31s patches.
>>>> I see there three options, which one do you prefer?:
>>>>
>>>> 1. Provide now placeholder patches and send new patches, if everything is
>>>> clear and other things are mainlined
>>>> 2. Provide now patches as complete as possible and provide later patches to
>>>> complete them when the R_PRCM things are mainlined
>>>> 3. Leave them out, till the related work is mainlined and the bindings are
>>>> final.
>>>
>>> Like I said, the DT *has* to be backward-compatible, so for any DT patch that
>>> you are asking to be merged, you should be prepared to support it indefinitely
>>> and be able to run from it, and you won't be able to change the bindings later
>>> on.
>>
>> I agree on your points. But is this also suitable to drivers that are
>> currently off tree and might be merged in one or two years?
>
> This is what we done for the Mali. The devicetree binding was first done for the
> out-of-tree driver, and then lima/panfrost reused it.
>
> The key thing here is to have enough confidence about how the hardware works so
> that you can accurately describe it.
Ok thanks! So I will resend my patches when the work got a more mature
state and we know enough about the Hardware.
Cheers,
Philipp
[1]:
https://elixir.bootlin.com/linux/latest/source/drivers/soc/amlogic/meson-gx-pwrc-vpu.c
next prev parent reply other threads:[~2020-04-21 18:17 UTC|newest]
Thread overview: 68+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-15 8:35 [PATCH v6 00/12] ARM/MIPS: DTS: add child nodes describing the PVRSGX GPU present in some OMAP SoC and JZ4780 (and many more) H. Nikolaus Schaller
2020-04-15 8:35 ` [PATCH v6 01/12] dt-bindings: add img,pvrsgx.yaml for Imagination GPUs H. Nikolaus Schaller
2020-04-15 10:12 ` Maxime Ripard
2020-04-15 12:43 ` H. Nikolaus Schaller
2020-04-15 12:54 ` [PATCH v6 01/12] dt-bindings: add img, pvrsgx.yaml " Neil Armstrong
2020-04-15 13:17 ` H. Nikolaus Schaller
2020-04-15 14:21 ` Maxime Ripard
2020-04-15 15:09 ` H. Nikolaus Schaller
2020-04-15 16:21 ` Maxime Ripard
2020-04-15 16:42 ` H. Nikolaus Schaller
2020-04-15 17:13 ` Tony Lindgren
2020-04-17 10:25 ` Maxime Ripard
2020-04-17 12:15 ` H. Nikolaus Schaller
2020-04-18 23:02 ` Philipp Rossak
2020-04-20 8:04 ` Maxime Ripard
2020-04-16 20:41 ` [PATCH v6 01/12] dt-bindings: add img,pvrsgx.yaml " Rob Herring
[not found] ` <C7C58E41-99CB-49F6-934E-68FA458CB8B1@goldelico.com>
2020-04-21 19:02 ` [PATCH v6 01/12] dt-bindings: add img, pvrsgx.yaml " Rob Herring
2020-04-15 8:35 ` [PATCH v6 02/12] ARM: DTS: am33xx: add sgx gpu child node H. Nikolaus Schaller
2020-04-15 8:35 ` [PATCH v6 03/12] ARM: DTS: am3517: " H. Nikolaus Schaller
2020-04-15 8:35 ` [PATCH v6 04/12] ARM: DTS: omap34xx: " H. Nikolaus Schaller
2020-04-15 8:35 ` [PATCH v6 05/12] ARM: DTS: omap36xx: " H. Nikolaus Schaller
2020-04-15 8:35 ` [PATCH v6 06/12] ARM: DTS: omap4: " H. Nikolaus Schaller
2020-04-15 8:35 ` [PATCH v6 07/12] ARM: DTS: omap5: " H. Nikolaus Schaller
2020-04-15 11:38 ` Krzysztof Kozlowski
2020-04-15 11:46 ` H. Nikolaus Schaller
2020-04-15 13:47 ` Krzysztof Kozlowski
2020-04-15 14:07 ` H. Nikolaus Schaller
2020-04-15 8:35 ` [PATCH v6 08/12] arm: dts: s5pv210: Add G3D node H. Nikolaus Schaller
2020-04-15 9:15 ` Sergei Shtylyov
2020-04-15 9:26 ` H. Nikolaus Schaller
2020-04-15 11:49 ` Krzysztof Kozlowski
2020-04-15 12:50 ` H. Nikolaus Schaller
2020-04-15 13:44 ` Krzysztof Kozlowski
2020-04-15 18:17 ` Jonathan Bakker
2020-04-16 8:50 ` Krzysztof Kozlowski
2020-04-17 12:15 ` H. Nikolaus Schaller
2020-04-22 5:56 ` kbuild test robot
2020-04-15 8:35 ` [PATCH v6 09/12] ARM: dts: sun6i: a31: add sgx gpu child node H. Nikolaus Schaller
2020-04-15 8:35 ` [PATCH v6 10/12] ARM: dts: sun6i: a31s: " H. Nikolaus Schaller
2020-04-15 8:35 ` [PATCH v6 11/12] ARM: dts: sun8i: a83t: " H. Nikolaus Schaller
2020-04-15 8:35 ` [PATCH v6 12/12] MIPS: DTS: jz4780: add sgx gpu node H. Nikolaus Schaller
2020-04-15 10:10 ` [PATCH v6 00/12] ARM/MIPS: DTS: add child nodes describing the PVRSGX GPU present in some OMAP SoC and JZ4780 (and many more) Maxime Ripard
2020-04-15 12:41 ` H. Nikolaus Schaller
2020-04-15 12:46 ` Daniel Vetter
2020-04-15 13:02 ` Maxime Ripard
2020-04-15 13:04 ` H. Nikolaus Schaller
2020-04-17 12:09 ` Philipp Rossak
2020-04-20 7:38 ` Maxime Ripard
2020-04-21 9:57 ` Philipp Rossak
2020-04-21 11:21 ` Maxime Ripard
2020-04-21 14:15 ` Tony Lindgren
2020-04-21 17:29 ` H. Nikolaus Schaller
2020-04-21 17:39 ` Tony Lindgren
2020-04-21 17:46 ` Tony Lindgren
2020-04-22 6:58 ` Maxime Ripard
2020-04-22 7:10 ` H. Nikolaus Schaller
2020-04-22 15:13 ` Maxime Ripard
2020-04-22 16:09 ` H. Nikolaus Schaller
[not found] ` <MC879Q.XY9S0U9R35681@crapouillou.net>
2020-04-22 17:23 ` H. Nikolaus Schaller
2020-04-22 19:00 ` Philipp Rossak
2020-04-22 19:33 ` Tony Lindgren
2020-04-22 21:12 ` H. Nikolaus Schaller
2020-04-23 15:00 ` Neil Armstrong
2020-04-23 15:45 ` H. Nikolaus Schaller
2020-04-23 20:36 ` Maxime Ripard
2020-04-24 9:51 ` H. Nikolaus Schaller
2020-04-21 16:42 ` Philipp Rossak [this message]
2020-04-23 20:37 ` Maxime Ripard
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=5749af21-e707-c998-c83b-50c48867c9e8@gmail.com \
--to=embed3d@gmail.com \
--cc=airlied@linux.ie \
--cc=bcousson@baylibre.com \
--cc=daniel@ffwll.ch \
--cc=devicetree@vger.kernel.org \
--cc=dri-devel@lists.freedesktop.org \
--cc=hns@goldelico.com \
--cc=jhogan@kernel.org \
--cc=kernel@pyra-handheld.com \
--cc=kgene@kernel.org \
--cc=krzk@kernel.org \
--cc=letux-kernel@openphoenux.org \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mips@vger.kernel.org \
--cc=linux-omap@vger.kernel.org \
--cc=linux-samsung-soc@vger.kernel.org \
--cc=mark.rutland@arm.com \
--cc=maxime@cerno.tech \
--cc=openpvrsgx-devgroup@letux.org \
--cc=paul@crapouillou.net \
--cc=paulburton@kernel.org \
--cc=ralf@linux-mips.org \
--cc=robh+dt@kernel.org \
--cc=tony@atomide.com \
--cc=tsbogend@alpha.franken.de \
--cc=wens@csie.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).