From: Arnd Bergmann <arnd@arndb.de> To: "Hawkins, Nick" <nick.hawkins@hpe.com> Cc: Arnd Bergmann <arnd@arndb.de>, "Verdun, Jean-Marie" <verdun@hpe.com>, Olof Johansson <olof@lixom.net>, "soc@kernel.org" <soc@kernel.org>, Rob Herring <robh+dt@kernel.org>, "linux-arm-kernel@lists.infradead.org" <linux-arm-kernel@lists.infradead.org>, "devicetree@vger.kernel.org" <devicetree@vger.kernel.org>, "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org> Subject: Re: [PATCH v3 09/10] arch: arm: boot: dts: Introduce HPE GXP Device tree Date: Wed, 6 Apr 2022 09:24:40 +0200 [thread overview] Message-ID: <CAK8P3a3jr-FkyxLff2cK4=X-4AShnKkeYMRKsvUg=2W0bTviiQ@mail.gmail.com> (raw) In-Reply-To: <PH0PR84MB1718C7447207BF210FBB477788E49@PH0PR84MB1718.NAMPRD84.PROD.OUTLOOK.COM> On Tue, Apr 5, 2022 at 11:21 PM Hawkins, Nick <nick.hawkins@hpe.com> wrote: > > > Right, it is possible to make this work, but it's not recommended, and you have to work around the sanity checks in the code that try to keep you from doing it wrong, as well as any tooling that tries to check for these in the DT. > > I found an example in the kernel where the timer creates a child watchdog device and passes it the base address when creating it. I used this to model the gxp-timer and gxp-wdt. The following files were what I have referenced: > drivers/watchdog/ixp4xx_wdt.c > drivers/clocksource/timer-ixp4xx.c Yes, I think that is a good example. > This seems very similar to what you suggested previously except I do not see a private interface in there between the parent and the child device. Is it mandatory to have the private interface between the two? If it is, what would you recommend that interface be? So far without the private interface I am not seeing any issues accessing the registers. I would count passing a register address to the child device as a private interface. It's a minimalistic one, but that is not a bad thing here. Arnd
WARNING: multiple messages have this Message-ID (diff)
From: Arnd Bergmann <arnd@arndb.de> To: "Hawkins, Nick" <nick.hawkins@hpe.com> Cc: Arnd Bergmann <arnd@arndb.de>, "Verdun, Jean-Marie" <verdun@hpe.com>, Olof Johansson <olof@lixom.net>, "soc@kernel.org" <soc@kernel.org>, Rob Herring <robh+dt@kernel.org>, "linux-arm-kernel@lists.infradead.org" <linux-arm-kernel@lists.infradead.org>, "devicetree@vger.kernel.org" <devicetree@vger.kernel.org>, "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org> Subject: Re: [PATCH v3 09/10] arch: arm: boot: dts: Introduce HPE GXP Device tree Date: Wed, 6 Apr 2022 09:24:40 +0200 [thread overview] Message-ID: <CAK8P3a3jr-FkyxLff2cK4=X-4AShnKkeYMRKsvUg=2W0bTviiQ@mail.gmail.com> (raw) In-Reply-To: <PH0PR84MB1718C7447207BF210FBB477788E49@PH0PR84MB1718.NAMPRD84.PROD.OUTLOOK.COM> On Tue, Apr 5, 2022 at 11:21 PM Hawkins, Nick <nick.hawkins@hpe.com> wrote: > > > Right, it is possible to make this work, but it's not recommended, and you have to work around the sanity checks in the code that try to keep you from doing it wrong, as well as any tooling that tries to check for these in the DT. > > I found an example in the kernel where the timer creates a child watchdog device and passes it the base address when creating it. I used this to model the gxp-timer and gxp-wdt. The following files were what I have referenced: > drivers/watchdog/ixp4xx_wdt.c > drivers/clocksource/timer-ixp4xx.c Yes, I think that is a good example. > This seems very similar to what you suggested previously except I do not see a private interface in there between the parent and the child device. Is it mandatory to have the private interface between the two? If it is, what would you recommend that interface be? So far without the private interface I am not seeing any issues accessing the registers. I would count passing a register address to the child device as a private interface. It's a minimalistic one, but that is not a bad thing here. Arnd _______________________________________________ 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:[~2022-04-06 11:56 UTC|newest] Thread overview: 80+ messages / expand[flat|nested] mbox.gz Atom feed top 2022-03-10 19:52 [PATCH v3 01/10] arch: arm: mach-hpe: Introduce the HPE GXP architecture nick.hawkins 2022-03-10 19:52 ` nick.hawkins 2022-03-10 19:52 ` [PATCH v3 02/10] arch: arm: configs: multi_v7_defconfig nick.hawkins 2022-03-10 19:52 ` nick.hawkins 2022-03-10 19:52 ` [PATCH v3 03/10] drivers: wdt: Introduce HPE GXP SoC Watchdog nick.hawkins 2022-04-04 14:28 ` Guenter Roeck 2022-04-04 16:25 ` Hawkins, Nick 2022-04-04 16:41 ` Guenter Roeck 2022-03-10 19:52 ` [PATCH v3 04/10] clocksource/drivers: Add HPE GXP timer nick.hawkins 2022-04-06 11:13 ` Daniel Lezcano 2022-04-06 22:02 ` Hawkins, Nick 2022-03-10 19:52 ` [PATCH v3 05/10] dt-bindings: timer: Add HPE GXP Timer Binding nick.hawkins 2022-03-11 9:32 ` Krzysztof Kozlowski 2022-03-11 15:40 ` Rob Herring 2022-03-11 16:22 ` Hawkins, Nick 2022-03-11 17:13 ` Krzysztof Kozlowski 2022-03-10 19:52 ` [PATCH v3 06/10] dt-bindings: watchdog: Add HPE GXP Watchdog timer binding nick.hawkins 2022-03-11 9:34 ` Krzysztof Kozlowski 2022-03-10 19:52 ` [PATCH v3 07/10] dt-bindings: arm: Add HPE GXP Binding nick.hawkins 2022-03-11 10:20 ` Krzysztof Kozlowski 2022-03-10 19:52 ` [PATCH v3 08/10] dt-bindings: arm: Add HPE GXP CPU Init nick.hawkins 2022-03-11 10:22 ` Krzysztof Kozlowski 2022-03-16 21:33 ` Hawkins, Nick 2022-03-10 19:52 ` [PATCH v3 09/10] arch: arm: boot: dts: Introduce HPE GXP Device tree nick.hawkins 2022-03-10 19:52 ` nick.hawkins 2022-03-11 8:17 ` Arnd Bergmann 2022-03-11 8:17 ` Arnd Bergmann 2022-03-11 10:29 ` Krzysztof Kozlowski 2022-03-11 10:29 ` Krzysztof Kozlowski 2022-03-16 15:41 ` Hawkins, Nick 2022-03-16 15:41 ` Hawkins, Nick 2022-03-16 15:50 ` Krzysztof Kozlowski 2022-03-16 15:50 ` Krzysztof Kozlowski 2022-03-16 20:10 ` Hawkins, Nick 2022-03-16 20:10 ` Hawkins, Nick 2022-03-17 8:36 ` Krzysztof Kozlowski 2022-03-17 8:36 ` Krzysztof Kozlowski 2022-03-29 19:38 ` Hawkins, Nick 2022-03-29 19:38 ` Hawkins, Nick 2022-03-29 21:13 ` Arnd Bergmann 2022-03-29 21:13 ` Arnd Bergmann 2022-03-29 21:45 ` Hawkins, Nick 2022-03-29 21:45 ` Hawkins, Nick 2022-03-30 22:27 ` Hawkins, Nick 2022-03-30 22:27 ` Hawkins, Nick 2022-03-31 9:30 ` Arnd Bergmann 2022-03-31 9:30 ` Arnd Bergmann 2022-03-31 21:09 ` Hawkins, Nick 2022-03-31 21:09 ` Hawkins, Nick 2022-03-31 21:52 ` Arnd Bergmann 2022-03-31 21:52 ` Arnd Bergmann 2022-04-01 16:05 ` Hawkins, Nick 2022-04-01 16:05 ` Hawkins, Nick 2022-04-01 16:30 ` Arnd Bergmann 2022-04-01 16:30 ` Arnd Bergmann 2022-04-04 20:22 ` Hawkins, Nick 2022-04-04 20:22 ` Hawkins, Nick 2022-04-04 22:02 ` Arnd Bergmann 2022-04-04 22:02 ` Arnd Bergmann 2022-04-05 21:21 ` Hawkins, Nick 2022-04-05 21:21 ` Hawkins, Nick 2022-04-06 7:24 ` Arnd Bergmann [this message] 2022-04-06 7:24 ` Arnd Bergmann 2022-04-13 16:48 ` Hawkins, Nick 2022-04-13 16:48 ` Hawkins, Nick 2022-04-13 17:42 ` Arnd Bergmann 2022-04-13 17:42 ` Arnd Bergmann 2022-03-10 19:52 ` [PATCH v3 10/10] maintainers: Introduce HPE GXP Architecture nick.hawkins 2022-03-11 10:33 ` Joe Perches 2022-03-11 7:21 ` [PATCH v3 01/10] arch: arm: mach-hpe: Introduce the HPE GXP architecture kernel test robot 2022-03-11 7:21 ` kernel test robot 2022-03-11 8:06 ` Arnd Bergmann 2022-03-11 8:06 ` Arnd Bergmann 2022-03-11 12:40 ` kernel test robot 2022-03-11 12:40 ` kernel test robot 2022-03-12 13:27 ` kernel test robot 2022-03-12 13:27 ` kernel test robot 2022-03-12 15:14 ` Arnd Bergmann 2022-03-12 15:14 ` Arnd Bergmann 2022-03-12 15:14 ` Arnd Bergmann
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