From: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org> To: Viorel Suman <viorel.suman@nxp.com> Cc: "Viorel Suman (OSS)" <viorel.suman@oss.nxp.com>, Rob Herring <robh+dt@kernel.org>, Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>, Michael Turquette <mturquette@baylibre.com>, Stephen Boyd <sboyd@kernel.org>, Dmitry Torokhov <dmitry.torokhov@gmail.com>, Srinivas Kandagatla <srinivas.kandagatla@linaro.org>, Dong Aisheng <aisheng.dong@nxp.com>, Fabio Estevam <festevam@gmail.com>, Shawn Guo <shawnguo@kernel.org>, Stefan Agner <stefan@agner.ch>, Pengutronix Kernel Team <kernel@pengutronix.de>, Linus Walleij <linus.walleij@linaro.org>, Alessandro Zummo <a.zummo@towertech.it>, Alexandre Belloni <alexandre.belloni@bootlin.com>, "Rafael J. Wysocki" <rafael@kernel.org>, Daniel Lezcano <daniel.lezcano@linaro.org>, Amit Kucheria <amitk@kernel.org>, Zhang Rui <rui.zhang@intel.com>, Wim Van Sebroeck <wim@linux-watchdog.org>, Guenter Roeck <linux@roeck-us.net>, Sascha Hauer <s.hauer@pengutronix.de>, NXP Linux Team <linux-imx@nxp.com>, Abel Vesa <abelvesa@kernel.org>, Oliver Graute <oliver.graute@kococonnector.com>, Liu Ying <victor.liu@nxp.com>, Mirela Rabulea <mirela.rabulea@nxp.com>, Peng Fan <peng.fan@nxp.com>, Ming Qian <ming.qian@nxp.com>, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-clk@vger.kernel.org, linux-input@vger.kernel.org, linux-gpio@vger.kernel.org, linux-rtc@vger.kernel.org, linux-pm@vger.kernel.org, linux-watchdog@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH v6 10/14] arm64: dts: freescale: imx8qxp: Remove unnecessary clock related entries Date: Thu, 30 Jun 2022 20:01:31 +0200 [thread overview] Message-ID: <5d8b2044-5ca6-c90c-57b4-afbb2ae20dde@linaro.org> (raw) In-Reply-To: <20220630083636.2c7mclmbq3tjma2j@fsr-ub1664-116> On 30/06/2022 10:36, Viorel Suman wrote: > On 22-06-29 20:04:43, Krzysztof Kozlowski wrote: >> On 29/06/2022 18:44, Viorel Suman (OSS) wrote: >>> From: Viorel Suman <viorel.suman@nxp.com> >>> >>> "clocks" and "clock-names" are not used the driver, so >>> remove them in order to match the yaml definition. >> >> So this explains the unexpected change in the bindings... but actually >> it does not explain whether it is correct or not. Just because driver >> does not use it, is not a proof that clocks are not there. In different >> OS/implementation this DTS might break stuff, so basically it is ABI >> break. DTS should describe the hardware fully, so if the clocks are >> there, should be in DTS regardless of the driver. > > Hi Krzysztof, > > Both XTAL clocks - 24MHz and 32kHz - are still defined in DTSI files, see for instance in > arch/arm64/boot/dts/freescale/imx8qxp.dtsi : > --------------- > xtal32k: clock-xtal32k { > compatible = "fixed-clock"; > #clock-cells = <0>; > clock-frequency = <32768>; > clock-output-names = "xtal_32KHz"; > }; > > xtal24m: clock-xtal24m { > compatible = "fixed-clock"; > #clock-cells = <0>; > clock-frequency = <24000000>; > clock-output-names = "xtal_24MHz"; > }; > --------------- > Both can be seen in /sys/kernel/debug/clk/clk_summary once boot is complete, both can be referenced > in any DTS node, so there is no ABI break. ABI break is not relevant to the fixed clocks being or not being defined in the DTS. You have a device which was taking the clock inputs, so the clocks stayed enabled. Now, you don't take these inputs, so for example the clocks are getting disabled as not used. > > "DTS should describe the hardware fully" - this is true in case the OS is supposed to controll the > hardware fully. i.MX8 System Controller Unit concept implies resources being allocated and managed > by SCU, there is no direct OS access to some hardware. SCU actually defines the hardware environment > the OS is being able to see and run within. SCU is able to define several such isolated hardware > environments, each having its own OS running. So, in this particular case - i.MX8 SCU concept - > DTS should describe the hardware from the perspective of the hardware environment exposed by SCU to > OS. OK, that sounds good, but the question about these clocks remain - are they inputs to the SCU or not. Regardless whether they are actual input or not, you used not appropriate argument here - that Linux OS implementation does not use them. The proper argument is - whether the hardware environment has them connected or not. Best regards, Krzysztof
WARNING: multiple messages have this Message-ID (diff)
From: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org> To: Viorel Suman <viorel.suman@nxp.com> Cc: "Viorel Suman (OSS)" <viorel.suman@oss.nxp.com>, Rob Herring <robh+dt@kernel.org>, Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>, Michael Turquette <mturquette@baylibre.com>, Stephen Boyd <sboyd@kernel.org>, Dmitry Torokhov <dmitry.torokhov@gmail.com>, Srinivas Kandagatla <srinivas.kandagatla@linaro.org>, Dong Aisheng <aisheng.dong@nxp.com>, Fabio Estevam <festevam@gmail.com>, Shawn Guo <shawnguo@kernel.org>, Stefan Agner <stefan@agner.ch>, Pengutronix Kernel Team <kernel@pengutronix.de>, Linus Walleij <linus.walleij@linaro.org>, Alessandro Zummo <a.zummo@towertech.it>, Alexandre Belloni <alexandre.belloni@bootlin.com>, "Rafael J. Wysocki" <rafael@kernel.org>, Daniel Lezcano <daniel.lezcano@linaro.org>, Amit Kucheria <amitk@kernel.org>, Zhang Rui <rui.zhang@intel.com>, Wim Van Sebroeck <wim@linux-watchdog.org>, Guenter Roeck <linux@roeck-us.net>, Sascha Hauer <s.hauer@pengutronix.de>, NXP Linux Team <linux-imx@nxp.com>, Abel Vesa <abelvesa@kernel.org>, Oliver Graute <oliver.graute@kococonnector.com>, Liu Ying <victor.liu@nxp.com>, Mirela Rabulea <mirela.rabulea@nxp.com>, Peng Fan <peng.fan@nxp.com>, Ming Qian <ming.qian@nxp.com>, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-clk@vger.kernel.org, linux-input@vger.kernel.org, linux-gpio@vger.kernel.org, linux-rtc@vger.kernel.org, linux-pm@vger.kernel.org, linux-watchdog@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH v6 10/14] arm64: dts: freescale: imx8qxp: Remove unnecessary clock related entries Date: Thu, 30 Jun 2022 20:01:31 +0200 [thread overview] Message-ID: <5d8b2044-5ca6-c90c-57b4-afbb2ae20dde@linaro.org> (raw) In-Reply-To: <20220630083636.2c7mclmbq3tjma2j@fsr-ub1664-116> On 30/06/2022 10:36, Viorel Suman wrote: > On 22-06-29 20:04:43, Krzysztof Kozlowski wrote: >> On 29/06/2022 18:44, Viorel Suman (OSS) wrote: >>> From: Viorel Suman <viorel.suman@nxp.com> >>> >>> "clocks" and "clock-names" are not used the driver, so >>> remove them in order to match the yaml definition. >> >> So this explains the unexpected change in the bindings... but actually >> it does not explain whether it is correct or not. Just because driver >> does not use it, is not a proof that clocks are not there. In different >> OS/implementation this DTS might break stuff, so basically it is ABI >> break. DTS should describe the hardware fully, so if the clocks are >> there, should be in DTS regardless of the driver. > > Hi Krzysztof, > > Both XTAL clocks - 24MHz and 32kHz - are still defined in DTSI files, see for instance in > arch/arm64/boot/dts/freescale/imx8qxp.dtsi : > --------------- > xtal32k: clock-xtal32k { > compatible = "fixed-clock"; > #clock-cells = <0>; > clock-frequency = <32768>; > clock-output-names = "xtal_32KHz"; > }; > > xtal24m: clock-xtal24m { > compatible = "fixed-clock"; > #clock-cells = <0>; > clock-frequency = <24000000>; > clock-output-names = "xtal_24MHz"; > }; > --------------- > Both can be seen in /sys/kernel/debug/clk/clk_summary once boot is complete, both can be referenced > in any DTS node, so there is no ABI break. ABI break is not relevant to the fixed clocks being or not being defined in the DTS. You have a device which was taking the clock inputs, so the clocks stayed enabled. Now, you don't take these inputs, so for example the clocks are getting disabled as not used. > > "DTS should describe the hardware fully" - this is true in case the OS is supposed to controll the > hardware fully. i.MX8 System Controller Unit concept implies resources being allocated and managed > by SCU, there is no direct OS access to some hardware. SCU actually defines the hardware environment > the OS is being able to see and run within. SCU is able to define several such isolated hardware > environments, each having its own OS running. So, in this particular case - i.MX8 SCU concept - > DTS should describe the hardware from the perspective of the hardware environment exposed by SCU to > OS. OK, that sounds good, but the question about these clocks remain - are they inputs to the SCU or not. Regardless whether they are actual input or not, you used not appropriate argument here - that Linux OS implementation does not use them. The proper argument is - whether the hardware environment has them connected or not. Best regards, Krzysztof _______________________________________________ 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:[~2022-06-30 18:01 UTC|newest] Thread overview: 98+ messages / expand[flat|nested] mbox.gz Atom feed top 2022-06-29 16:44 [PATCH v6 00/14] dt-bindings: arm: freescale: Switch fsl,scu from txt to yaml Viorel Suman (OSS) 2022-06-29 16:44 ` Viorel Suman (OSS) 2022-06-29 16:44 ` [PATCH v6 01/14] dt-bindings: clk: imx: Add fsl,scu-clk yaml file Viorel Suman (OSS) 2022-06-29 16:44 ` Viorel Suman (OSS) 2022-06-29 17:48 ` Krzysztof Kozlowski 2022-06-29 17:48 ` Krzysztof Kozlowski 2022-06-29 16:44 ` [PATCH v6 02/14] dt-bindings: pinctrl: imx: Add fsl,scu-iomux " Viorel Suman (OSS) 2022-06-29 16:44 ` Viorel Suman (OSS) 2022-06-29 17:53 ` Krzysztof Kozlowski 2022-06-29 17:53 ` Krzysztof Kozlowski 2022-06-30 12:37 ` Viorel Suman (OSS) 2022-06-30 12:37 ` Viorel Suman (OSS) 2022-06-30 18:33 ` Krzysztof Kozlowski 2022-06-30 18:33 ` Krzysztof Kozlowski 2022-07-05 18:33 ` Rob Herring 2022-07-05 18:33 ` Rob Herring 2022-07-06 14:11 ` Rob Herring 2022-07-06 14:11 ` Rob Herring 2022-07-06 14:29 ` Krzysztof Kozlowski 2022-07-06 14:29 ` Krzysztof Kozlowski 2022-06-30 13:44 ` Rob Herring 2022-06-30 13:44 ` Rob Herring 2022-06-29 16:44 ` [PATCH v6 03/14] dt-bindings: input: Add fsl,scu-key " Viorel Suman (OSS) 2022-06-29 16:44 ` Viorel Suman (OSS) 2022-06-29 17:54 ` Krzysztof Kozlowski 2022-06-29 17:54 ` Krzysztof Kozlowski 2022-06-29 16:44 ` [PATCH v6 04/14] dt-bindings: nvmem: Add fsl,scu-ocotp " Viorel Suman (OSS) 2022-06-29 16:44 ` Viorel Suman (OSS) 2022-06-29 17:56 ` Krzysztof Kozlowski 2022-06-29 17:56 ` Krzysztof Kozlowski 2022-06-29 17:56 ` Krzysztof Kozlowski 2022-06-29 17:56 ` Krzysztof Kozlowski 2022-06-29 16:44 ` [PATCH v6 05/14] dt-bindings: power: Add fsl,scu-pd " Viorel Suman (OSS) 2022-06-29 16:44 ` Viorel Suman (OSS) 2022-06-29 17:57 ` Krzysztof Kozlowski 2022-06-29 17:57 ` Krzysztof Kozlowski 2022-06-29 16:44 ` [PATCH v6 06/14] dt-bindings: rtc: Add fsl,scu-rtc " Viorel Suman (OSS) 2022-06-29 16:44 ` Viorel Suman (OSS) 2022-06-29 17:58 ` Krzysztof Kozlowski 2022-06-29 17:58 ` Krzysztof Kozlowski 2022-06-29 16:44 ` [PATCH v6 07/14] dt-bindings: thermal: Add fsl,scu-thermal " Viorel Suman (OSS) 2022-06-29 16:44 ` Viorel Suman (OSS) 2022-06-29 17:59 ` Krzysztof Kozlowski 2022-06-29 17:59 ` Krzysztof Kozlowski 2022-06-29 16:44 ` [PATCH v6 08/14] dt-bindings: watchdog: Add fsl,scu-wdt " Viorel Suman (OSS) 2022-06-29 16:44 ` Viorel Suman (OSS) 2022-06-29 17:59 ` Krzysztof Kozlowski 2022-06-29 17:59 ` Krzysztof Kozlowski 2022-06-30 14:43 ` Guenter Roeck 2022-06-30 14:43 ` Guenter Roeck 2022-06-29 16:44 ` [PATCH v6 09/14] dt-bindings: firmware: Add fsl,scu " Viorel Suman (OSS) 2022-06-29 16:44 ` Viorel Suman (OSS) 2022-06-29 18:02 ` Krzysztof Kozlowski 2022-06-29 18:02 ` Krzysztof Kozlowski 2022-06-30 13:44 ` Rob Herring 2022-06-30 13:44 ` Rob Herring 2022-06-29 16:44 ` [PATCH v6 10/14] arm64: dts: freescale: imx8qxp: Remove unnecessary clock related entries Viorel Suman (OSS) 2022-06-29 16:44 ` Viorel Suman (OSS) 2022-06-29 18:04 ` Krzysztof Kozlowski 2022-06-29 18:04 ` Krzysztof Kozlowski 2022-06-30 8:36 ` Viorel Suman 2022-06-30 8:36 ` Viorel Suman 2022-06-30 18:01 ` Krzysztof Kozlowski [this message] 2022-06-30 18:01 ` Krzysztof Kozlowski 2022-06-30 19:48 ` Viorel Suman 2022-06-30 19:48 ` Viorel Suman 2022-07-04 8:06 ` Krzysztof Kozlowski 2022-07-04 8:06 ` Krzysztof Kozlowski 2022-06-29 16:44 ` [PATCH v6 11/14] arm64: dts: freescale: imx8: Fix power controller name Viorel Suman (OSS) 2022-06-29 16:44 ` Viorel Suman (OSS) 2022-06-29 18:05 ` Krzysztof Kozlowski 2022-06-29 18:05 ` Krzysztof Kozlowski 2022-06-29 16:44 ` [PATCH v6 12/14] arm64: dts: freescale: imx8qxp: Add fallback compatible for clock controller Viorel Suman (OSS) 2022-06-29 16:44 ` Viorel Suman (OSS) 2022-06-29 18:05 ` Krzysztof Kozlowski 2022-06-29 18:05 ` Krzysztof Kozlowski 2022-06-29 16:44 ` [PATCH v6 13/14] arm64: dts: freescale: imx8qxp: Fix the keys node name Viorel Suman (OSS) 2022-06-29 16:44 ` Viorel Suman (OSS) 2022-06-29 18:06 ` Krzysztof Kozlowski 2022-06-29 18:06 ` Krzysztof Kozlowski 2022-06-29 16:44 ` [PATCH v6 14/14] dt-bindings: arm: freescale: Remove fsl,scu txt file Viorel Suman (OSS) 2022-06-29 16:44 ` Viorel Suman (OSS) 2022-06-29 18:03 ` Krzysztof Kozlowski 2022-06-29 18:03 ` Krzysztof Kozlowski 2022-06-29 17:51 ` [PATCH v6 00/14] dt-bindings: arm: freescale: Switch fsl,scu from txt to yaml Krzysztof Kozlowski 2022-06-29 17:51 ` Krzysztof Kozlowski 2022-06-30 12:13 ` Viorel Suman (OSS) 2022-06-30 12:13 ` Viorel Suman (OSS) 2022-06-30 18:03 ` Krzysztof Kozlowski 2022-06-30 18:03 ` Krzysztof Kozlowski 2022-06-30 18:11 ` Viorel Suman 2022-06-30 18:11 ` Viorel Suman 2022-07-05 0:39 ` Shawn Guo 2022-07-05 0:39 ` Shawn Guo 2022-07-05 7:28 ` Krzysztof Kozlowski 2022-07-05 7:28 ` Krzysztof Kozlowski 2022-07-05 8:07 ` Viorel Suman 2022-07-05 8:07 ` Viorel Suman
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