From: Marco Felsch <m.felsch@pengutronix.de>
To: Ahmad Fatoum <a.fatoum@pengutronix.de>
Cc: barebox@lists.infradead.org
Subject: Re: [PATCH v2] ARM: dts: i.MX8MM: describe feature controller
Date: Tue, 30 Aug 2022 10:29:35 +0200 [thread overview]
Message-ID: <20220830082935.a4wvhzqynk2262ga@pengutronix.de> (raw)
In-Reply-To: <50c079c4-8cb6-5027-39f6-2936af2c3969@pengutronix.de>
On 22-08-30, Ahmad Fatoum wrote:
> Hello Marco,
>
> On 30.08.22 10:10, Marco Felsch wrote:
> > Hi Ahamd,
> >
> > On 22-08-30, Ahmad Fatoum wrote:
> >> Now with i.MX8M feature controller driver support available, have the
> >> OCOTP provide feature control on the i.MX8MM to ensure the kernel DT
> >> does not cause Linux to access the VPU and its power domains,
> >> when barebox knows them to be unavailable.
> >>
> >> This is needed because the upstream kernel imx8mm.dtsi only
> >> describes the full-featured SoC, which can lead to hangs when
> >> instantiating drivers for hardware that's unavailable in a
> >> less-featureful variant of the SoC.
> >>
> >> Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
> >> ---
> >> v1 was RFC patch 10/10 of:
> >> https://lore.barebox.org/barebox/20220818051955.2088238-11-a.fatoum@pengutronix.de/T/#u
> >>
> >> Patches 01-08 are still applicable, this replaces the approach in v1
> >> with a standalone feature controller with having the OCOTP as feature
> >> controller, like is done for i.MX8MN in patch 08/10 of above referenced
> >> series.
> >> ---
> >> arch/arm/dts/imx8mm.dtsi | 52 ++++++++++++++++++++++++++++++++++++++++
> >> 1 file changed, 52 insertions(+)
> >>
> >> diff --git a/arch/arm/dts/imx8mm.dtsi b/arch/arm/dts/imx8mm.dtsi
> >> index cdf212820594..1e81d03d6b84 100644
> >> --- a/arch/arm/dts/imx8mm.dtsi
> >> +++ b/arch/arm/dts/imx8mm.dtsi
> >> @@ -1,10 +1,18 @@
> >> // SPDX-License-Identifier: (GPL-2.0+ OR MIT)
> >> +
> >> +#include <dt-bindings/features/imx8m.h>
> >> +
> >> / {
> >> aliases {
> >> gpr.reboot_mode = &reboot_mode_gpr;
> >> };
> >> };
> >>
> >> +feat: &ocotp {
> >> + #feature-cells = <1>;
> >> + barebox,feature-controller;
> >> +};
> >
> > Why not just appending the node like:
> >
> > / {
> > aliases {
> > gpr.reboot_mode = &reboot_mode_gpr;
> > };
> >
> > feat: ocotp {
> > #feature-cells = <1>;
> > barebox,feature-controller;
> > };
> > };
>
> Yours adds a new /ocotp node while my patch gives the existing
> node pointed at by &ocotp an additional label and extends it.
This should extend the ocotp node as well or would it be a new node
due to the new label? To me it locked very strange, therefore I asked. I
never noticed that: "new_label: &old_label {}" is even possible.
Regards,
Marco
> I prefer the additional label, because it gives us flexibility
> in future if upstream decides that there should be a dedicated
> feature controller. In that case we would only need to move
> the label instead of touching all references. see RFC patch 10/10
> referenced above.
>
> Cheers,
> Ahmad
>
> >
> > Regards,
> > Marco
> >
> >> +
> >> &pgc_otg1 {
> >> barebox,allow-dummy;
> >> };
> >> @@ -24,3 +32,47 @@
> >> mode-serial = <0x00000010>, <0x40000000>;
> >> };
> >> };
> >> +
> >> +&A53_1 {
> >> + barebox,feature-gates = <&feat IMX8M_FEAT_CPU_DUAL>;
> >> +};
> >> +
> >> +&A53_2 {
> >> + barebox,feature-gates = <&feat IMX8M_FEAT_CPU_QUAD>;
> >> +};
> >> +
> >> +&A53_3 {
> >> + barebox,feature-gates = <&feat IMX8M_FEAT_CPU_QUAD>;
> >> +};
> >> +
> >> +&gpc {
> >> + barebox,feature-gates = <&feat 0>;
> >> +};
> >> +
> >> +&vpu_g1 {
> >> + barebox,feature-gates = <&feat IMX8M_FEAT_VPU>;
> >> +};
> >> +
> >> +&vpu_g2 {
> >> + barebox,feature-gates = <&feat IMX8M_FEAT_VPU>;
> >> +};
> >> +
> >> +&vpu_blk_ctrl {
> >> + barebox,feature-gates = <&feat IMX8M_FEAT_VPU>;
> >> +};
> >> +
> >> +&pgc_vpumix {
> >> + barebox,feature-gates = <&feat IMX8M_FEAT_VPU>;
> >> +};
> >> +
> >> +&pgc_vpu_g1 {
> >> + barebox,feature-gates = <&feat IMX8M_FEAT_VPU>;
> >> +};
> >> +
> >> +&pgc_vpu_g2 {
> >> + barebox,feature-gates = <&feat IMX8M_FEAT_VPU>;
> >> +};
> >> +
> >> +&pgc_vpu_h1 {
> >> + barebox,feature-gates = <&feat IMX8M_FEAT_VPU>;
> >> +};
> >> --
> >> 2.30.2
> >>
> >>
> >>
> >
>
>
> --
> Pengutronix e.K. | |
> Steuerwalder Str. 21 | http://www.pengutronix.de/ |
> 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 |
> Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |
>
next prev parent reply other threads:[~2022-08-30 8:31 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-08-30 7:50 Ahmad Fatoum
2022-08-30 8:10 ` Marco Felsch
2022-08-30 8:19 ` Ahmad Fatoum
2022-08-30 8:29 ` Marco Felsch [this message]
2022-08-30 9:01 ` Ahmad Fatoum
2022-08-31 6:41 ` Sascha Hauer
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=20220830082935.a4wvhzqynk2262ga@pengutronix.de \
--to=m.felsch@pengutronix.de \
--cc=a.fatoum@pengutronix.de \
--cc=barebox@lists.infradead.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