From: Lars Povlsen <lars.povlsen@microchip.com> To: Rob Herring <robh@kernel.org> Cc: Lars Povlsen <lars.povlsen@microchip.com>, Sebastian Reichel <sre@kernel.org>, SoC Team <soc@kernel.org>, Alexandre Belloni <alexandre.belloni@bootlin.com>, Microchip Linux Driver Support <UNGLinuxDriver@microchip.com>, <linux-pm@vger.kernel.org>, <devicetree@vger.kernel.org>, <linux-kernel@vger.kernel.org>, <linux-arm-kernel@lists.infradead.org> Subject: Re: [PATCH 3/5] dt-bindings: reset: ocelot: Add documentation for 'microchip,reset-switch-core' property Date: Tue, 2 Jun 2020 11:49:08 +0200 [thread overview] Message-ID: <87wo4piyqz.fsf@soft-dev15.microsemi.net> (raw) In-Reply-To: <20200528022502.GA3234572@bogus> Rob Herring writes: > On Wed, May 13, 2020 at 03:08:40PM +0200, Lars Povlsen wrote: >> This documents the 'microchip,reset-switch-core' property in the >> ocelot-reset driver. >> >> Signed-off-by: Lars Povlsen <lars.povlsen@microchip.com> >> --- >> .../devicetree/bindings/power/reset/ocelot-reset.txt | 6 ++++++ >> 1 file changed, 6 insertions(+) >> >> diff --git a/Documentation/devicetree/bindings/power/reset/ocelot-reset.txt b/Documentation/devicetree/bindings/power/reset/ocelot-reset.txt >> index 4d530d8154848..20fff03753ad2 100644 >> --- a/Documentation/devicetree/bindings/power/reset/ocelot-reset.txt >> +++ b/Documentation/devicetree/bindings/power/reset/ocelot-reset.txt >> @@ -9,9 +9,15 @@ microchip Sparx5 armv8 SoC's. >> Required Properties: >> - compatible: "mscc,ocelot-chip-reset" or "microchip,sparx5-chip-reset" >> >> +Optional properties: >> +- microchip,reset-switch-core : Perform a switch core reset at the >> + time of driver load. This is may be used to initialize the switch >> + core to a known state (before other drivers are loaded). > > How do you know when other drivers are loaded? This could be a module > perhaps. Doesn't seem like something that belongs in DT. > The reset driver is loaded at postcore_initcall() time, which ensures it is loaded before other drivers using the switch core. I noticed other drivers do the same to do low-level system reset and initialization at early boot time. > Can this behavior be implied with "microchip,sparx5-chip-reset"? Since we need to cater for both modus operandi, I would need two driver compatible strings per platform, which scales worse than a single property. The "microchip,reset-switch-core" is a device configuration property which tells the system (driver) how the hw should be handled. Since you do not *always* want to reset the switch core (f.ex. when implementing systems with warm reboot), I think it makes perfect sense - but I may be biased off course :-) Thank you for (all) of your comments, by the way! ---Lars > > Rob -- Lars Povlsen, Microchip
WARNING: multiple messages have this Message-ID (diff)
From: Lars Povlsen <lars.povlsen@microchip.com> To: Rob Herring <robh@kernel.org> Cc: devicetree@vger.kernel.org, Alexandre Belloni <alexandre.belloni@bootlin.com>, linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, Sebastian Reichel <sre@kernel.org>, Microchip Linux Driver Support <UNGLinuxDriver@microchip.com>, SoC Team <soc@kernel.org>, linux-arm-kernel@lists.infradead.org, Lars Povlsen <lars.povlsen@microchip.com> Subject: Re: [PATCH 3/5] dt-bindings: reset: ocelot: Add documentation for 'microchip, reset-switch-core' property Date: Tue, 2 Jun 2020 11:49:08 +0200 [thread overview] Message-ID: <87wo4piyqz.fsf@soft-dev15.microsemi.net> (raw) In-Reply-To: <20200528022502.GA3234572@bogus> Rob Herring writes: > On Wed, May 13, 2020 at 03:08:40PM +0200, Lars Povlsen wrote: >> This documents the 'microchip,reset-switch-core' property in the >> ocelot-reset driver. >> >> Signed-off-by: Lars Povlsen <lars.povlsen@microchip.com> >> --- >> .../devicetree/bindings/power/reset/ocelot-reset.txt | 6 ++++++ >> 1 file changed, 6 insertions(+) >> >> diff --git a/Documentation/devicetree/bindings/power/reset/ocelot-reset.txt b/Documentation/devicetree/bindings/power/reset/ocelot-reset.txt >> index 4d530d8154848..20fff03753ad2 100644 >> --- a/Documentation/devicetree/bindings/power/reset/ocelot-reset.txt >> +++ b/Documentation/devicetree/bindings/power/reset/ocelot-reset.txt >> @@ -9,9 +9,15 @@ microchip Sparx5 armv8 SoC's. >> Required Properties: >> - compatible: "mscc,ocelot-chip-reset" or "microchip,sparx5-chip-reset" >> >> +Optional properties: >> +- microchip,reset-switch-core : Perform a switch core reset at the >> + time of driver load. This is may be used to initialize the switch >> + core to a known state (before other drivers are loaded). > > How do you know when other drivers are loaded? This could be a module > perhaps. Doesn't seem like something that belongs in DT. > The reset driver is loaded at postcore_initcall() time, which ensures it is loaded before other drivers using the switch core. I noticed other drivers do the same to do low-level system reset and initialization at early boot time. > Can this behavior be implied with "microchip,sparx5-chip-reset"? Since we need to cater for both modus operandi, I would need two driver compatible strings per platform, which scales worse than a single property. The "microchip,reset-switch-core" is a device configuration property which tells the system (driver) how the hw should be handled. Since you do not *always* want to reset the switch core (f.ex. when implementing systems with warm reboot), I think it makes perfect sense - but I may be biased off course :-) Thank you for (all) of your comments, by the way! ---Lars > > Rob -- Lars Povlsen, Microchip _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2020-06-02 9:49 UTC|newest] Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top 2020-05-13 13:08 [PATCH 0/5] power: Adding support for Microchip Sparx5 SoC Lars Povlsen 2020-05-13 13:08 ` Lars Povlsen 2020-05-13 13:08 ` [PATCH 1/5] dt-bindings: reset: ocelot: Add Sparx5 support Lars Povlsen 2020-05-13 13:08 ` Lars Povlsen 2020-05-13 13:08 ` [PATCH 2/5] power: reset: ocelot: Add support for Sparx5 Lars Povlsen 2020-05-13 13:08 ` Lars Povlsen 2020-05-13 13:08 ` [PATCH 3/5] dt-bindings: reset: ocelot: Add documentation for 'microchip,reset-switch-core' property Lars Povlsen 2020-05-13 13:08 ` [PATCH 3/5] dt-bindings: reset: ocelot: Add documentation for 'microchip, reset-switch-core' property Lars Povlsen 2020-05-28 2:25 ` [PATCH 3/5] dt-bindings: reset: ocelot: Add documentation for 'microchip,reset-switch-core' property Rob Herring 2020-05-28 2:25 ` Rob Herring 2020-06-02 9:49 ` Lars Povlsen [this message] 2020-06-02 9:49 ` [PATCH 3/5] dt-bindings: reset: ocelot: Add documentation for 'microchip, reset-switch-core' property Lars Povlsen 2020-08-28 16:39 ` [PATCH 3/5] dt-bindings: reset: ocelot: Add documentation for 'microchip,reset-switch-core' property Sebastian Reichel 2020-08-31 8:19 ` Lars Povlsen 2020-08-31 8:19 ` [PATCH 3/5] dt-bindings: reset: ocelot: Add documentation for 'microchip, reset-switch-core' property Lars Povlsen 2020-09-16 8:00 ` [PATCH 3/5] dt-bindings: reset: ocelot: Add documentation for 'microchip,reset-switch-core' property Lars Povlsen 2020-09-29 22:04 ` Sebastian Reichel 2020-05-13 13:08 ` [PATCH 4/5] power: reset: ocelot: Add support for reset switch on load time Lars Povlsen 2020-05-13 13:08 ` Lars Povlsen 2020-05-13 13:08 ` [PATCH 5/5] arm64: dts: sparx5: Add reset support Lars Povlsen 2020-05-13 13:08 ` Lars Povlsen
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