Re: [PATCH v2 3/4] arm64: dts: imx8mp: Add MEDIAMIX power domains

From: Lucas Stach <l.stach@pengutronix.de>
To: Laurent Pinchart <laurent.pinchart@ideasonboard.com>,
	Marek Vasut <marex@denx.de>
Cc: linux-arm-kernel@lists.infradead.org,
	Shawn Guo <shawnguo@kernel.org>,
	 Sascha Hauer <s.hauer@pengutronix.de>,
	Pengutronix Kernel Team <kernel@pengutronix.de>,
	NXP Linux Team <linux-imx@nxp.com>,
	Fabio Estevam <festevam@gmail.com>,
	Paul Elder <paul.elder@ideasonboard.com>
Subject: Re: [PATCH v2 3/4] arm64: dts: imx8mp: Add MEDIAMIX power domains
Date: Wed, 23 Mar 2022 10:14:00 +0100	[thread overview]
Message-ID: <324276ea42a34f0862ca1d5f5c0aa4a68fa22657.camel@pengutronix.de> (raw)
In-Reply-To: <YjpHY0Iuu6xzaUj4@pendragon.ideasonboard.com>

Am Mittwoch, dem 23.03.2022 um 00:02 +0200 schrieb Laurent Pinchart:
> Hi Marek,
> 
> On Tue, Mar 22, 2022 at 10:31:59PM +0100, Marek Vasut wrote:
> > On 3/22/22 20:03, Laurent Pinchart wrote:
> > > Add the power domains related to the MEDIAMIX to the GPC.
> > > 
> > > Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> > > ---
> > >   arch/arm64/boot/dts/freescale/imx8mp.dtsi | 26 +++++++++++++++++++++++
> > >   1 file changed, 26 insertions(+)
> > > 
> > > diff --git a/arch/arm64/boot/dts/freescale/imx8mp.dtsi b/arch/arm64/boot/dts/freescale/imx8mp.dtsi
> > > index b40a5646f205..b440f22e03e5 100644
> > > --- a/arch/arm64/boot/dts/freescale/imx8mp.dtsi
> > > +++ b/arch/arm64/boot/dts/freescale/imx8mp.dtsi
> > > @@ -488,6 +488,11 @@ pgc {
> > >   					#address-cells = <1>;
> > >   					#size-cells = <0>;
> > >   
> > > +					pgc_mipi_phy1: power-domain@0 {
> > > +						#power-domain-cells = <0>;
> > > +						reg = <IMX8MP_POWER_DOMAIN_MIPI_PHY1>;
> > 
> > Shouldn't there be this here ?
> > 
> > power-domains = <&pgc_mediamix>;
> 
> I recall Lucas telling me it wasn't needed, and was instead handled
> internally in the gpcv2 driver, due to sequencing requirements, but I
> don't recall the details.

It's not handled by the gpcv2 driver, but the blk-ctrl driver. The blk-
ctrl driver handles the sequencing requirements when powering up/down
the "bus" domain, in that case the mediamix domain. In fact there must
not be any direct connection between the domains in the GPC DT
description as that would cause the requirements for clock and reset
propagation to be violated.

Regards,
Lucas

> 
> > > +					};
> > > +
> > >   					pgc_pcie_phy: power-domain@1 {
> > >   						#power-domain-cells = <0>;
> > >   						reg = <IMX8MP_POWER_DOMAIN_PCIE_PHY>;
> > > @@ -530,6 +535,21 @@ pgc_gpu3d: power-domain@9 {
> > >   						power-domains = <&pgc_gpumix>;
> > >   					};
> > >   
> > > +					pgc_mediamix: power-domain@10 {
> > > +						#power-domain-cells = <0>;
> > > +						reg = <IMX8MP_POWER_DOMAIN_MEDIAMIX>;
> > > +						clocks = <&clk IMX8MP_CLK_MEDIA_AXI_ROOT>,
> > > +							 <&clk IMX8MP_CLK_MEDIA_APB_ROOT>;
> > > +						assigned-clocks = <&clk IMX8MP_CLK_MEDIA_AXI_ROOT>,
> > > +								  <&clk IMX8MP_CLK_MEDIA_APB_ROOT>;
> > > +						assigned-clock-rates = <500000000>, <200000000>;
> > > +					};
> > > +
> > > +					pgc_mipi_phy2: power-domain@16 {
> > > +						#power-domain-cells = <0>;
> > > +						reg = <IMX8MP_POWER_DOMAIN_MIPI_PHY2>;
> > 
> > Here too ?
> 

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel