From patchwork Sat Sep 23 14:34:36 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?J=2E_Neusch=C3=A4fer?= X-Patchwork-Id: 725924 Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id DC50615E87 for ; Sat, 23 Sep 2023 14:35:19 +0000 (UTC) Received: from mout.gmx.net (mout.gmx.net [212.227.17.20]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 93C37194; Sat, 23 Sep 2023 07:35:17 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gmx.net; s=s31663417; t=1695479683; x=1696084483; i=j.neuschaefer@gmx.net; bh=dvKvVfdFWt0T6+IxwlCoYu30i3x8XW2yju8XY7g7TQw=; h=X-UI-Sender-Class:From:To:Cc:Subject:Date:In-Reply-To:References; b=NjcX7JuNB7G35RnJvp3Ui/BeOwRTDdGpinLIym4t65fpb3oo/FAWuz4uE+a9H9ApswJpQoKNVNd ov7hIKJ0sVtPKHofLhq2Zf11gKoTd0VgoHCnisWY0QpoBbvWYdLPOg4opDTzEVLGUwODmfi7OmfMP sryJYn040Kwiyz/eGkT811K2euS4j2BYplRyc+tkFdFtTRX9dCKM7wAKAMUyrjOK17vpeM+DKV4au 06+hG4+uBj6JUZAcJkuUbAjKJm46fnBa66tUbXClVG4gjM2nmX3DxE2nIFulrTz7l9UWuPRg5KI5N QgF28iFev+AJ6KrtBey5xXqJ0lUuItKUJ/Dg== X-UI-Sender-Class: 724b4f7f-cbec-4199-ad4e-598c01a50d3a Received: from probook ([89.0.47.152]) by mail.gmx.net (mrgmx105 [212.227.17.168]) with ESMTPSA (Nemesis) id 1MIx3C-1qyqVt35sw-00KO15; Sat, 23 Sep 2023 16:34:43 +0200 From: =?utf-8?q?Jonathan_Neusch=C3=A4fer?= To: linux-clk@vger.kernel.org, openbmc@lists.ozlabs.org Cc: linux-kernel@vger.kernel.org, linux-watchdog@vger.kernel.org, devicetree@vger.kernel.org, =?utf-8?q?Jonathan_Neusch=C3=A4fer?= , Michael Turquette , Stephen Boyd , Rob Herring , Krzysztof Kozlowski , Avi Fishman , Tomer Maimon , Tali Perry , Patrick Venture , Nancy Yuen , Benjamin Fair , Daniel Lezcano , Thomas Gleixner , Philipp Zabel , Wim Van Sebroeck , Guenter Roeck , Christophe JAILLET , Conor Dooley , Krzysztof Kozlowski Subject: [PATCH v9 1/3] dt-bindings: clock: Add Nuvoton WPCM450 clock/reset controller Date: Sat, 23 Sep 2023 16:34:36 +0200 Message-Id: <20230923143438.1895461-2-j.neuschaefer@gmx.net> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20230923143438.1895461-1-j.neuschaefer@gmx.net> References: <20230923143438.1895461-1-j.neuschaefer@gmx.net> Precedence: bulk X-Mailing-List: devicetree@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Provags-ID: V03:K1:mslaQFimglJP+UqzYug/aoohF1vHtd/u37CmOlAgx0oZtkTJ7uH yoijsWD8+rPUXCaOxysdEIPP8tgfkEb4SARqWdzM+C/MW9bZJgq8rHU5HcsLO9TB5IdLgAa fid36w/pNzakbjTNuXch7uMJtak5Fd1YsGPAtn4iI669XKY+TEDdpzxcnUu2qOjh9tZN4nF vUPyzIoXARk8Vn/PHkuGA== UI-OutboundReport: notjunk:1;M01:P0:5WCmLvF6sHY=;hSYyI2jgSuYsysimdRz4DL+S0Fd SZ23WUWdPDDoOqILnQIkZfCqE4p8pmYoGMfxuMFoqyFY5pFPJQm/00LgU2SVHyfmstPqGOO7E alAu6RpVxpTq3fW3BVktPW86Ye1vd4OmZJgtJSGkv5bK6tqWcGL2qyUgOzpvSYTnYCCDjNGN3 HtRLCu17Y+0fupQFOH8QJMRqZVtYrOAN2TxX4XzYYW+4IfoljnF+jC55qjpw5ttowW/e+7dPX 97xSwd5s2Mz4ti+prDjopUK/j4824rQMBnvKUwyJHO56NZFP9ku9hKRpEW6SKCVV0RDNR4CJy Kw5B3mgBXt8VPRYYFlUKtAnQGkU/jluD4q52xGx9F/kZC38Fey8RW0CHEXL/c0pMG1DsSGxtg GDdekCOIGVU14ZWy+evziD6/+G7CLzgIxI0NY7YV5rhQefg8Pis+wbR/YB+dU/mmLzT+Itsw1 V452AX+1XT5BWi0nBwK9+qbSHk6yrpWsWDD1MbA7ySnhobkPexsJkRZx5+G1H5y+l0lPI5D4d 5npCUinjoWvCwHwnW7m57rj2NTv3lEqf3GAGPRfmbkb+mfb8JBvepcaDW2kLjZvsiIoaI+wtY OcLKCkDbXb8YYoypcsizXt/g9Ra5jPDw3NE9VkBc4+XRNitDJcAxx1g2JvcS5lwGGdX3rVYd7 Ua/yd5CRtJ4yPvg8WiYOk6d6WrG0LTV1YKma16zee3bACs607cvl4TpkRhRsp5i+C7HUGSfVQ 8PkIwaYUkmWtNXEqpznzBGtzpoolGInzVbxVg+Ac/v2X+UC70rAbQAtDk8zQcJdzzHgd/dzYP 6D/cqkYsBVZ3uVzGhJnT1An70ONiMFF/c3nkS+Z4/bIV6MVsAYNgHsZ6P9u/WNaqanKoYojz+ xkj2H5d2KoM01Xhql1m8ConyTMZbKXuK6YigU4KP3iRTC4udA5lH9QApoC+6jvmCcVGA/eegF bZdi0bZP+msZI/q42sZzq5P0KH4= X-Spam-Status: No, score=-2.1 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,FREEMAIL_FROM, RCVD_IN_DNSWL_BLOCKED,RCVD_IN_MSPIKE_H4,RCVD_IN_MSPIKE_WL, SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net The Nuvoton WPCM450 SoC has a combined clock and reset controller. Add a devicetree binding for it, as well as definitions for the bit numbers used by it. Signed-off-by: Jonathan Neuschäfer Reviewed-by: Krzysztof Kozlowski --- v9: - Remove clock-output-names in example, because it's now unnecessary due to driver improvements v5-v8: - no changes v4: - https://lore.kernel.org/lkml/20220610072141.347795-4-j.neuschaefer@gmx.net/ - Add R-b tag v3: - Change clock-output-names and clock-names from "refclk" to "ref", suggested by Krzysztof Kozlowski v2: - https://lore.kernel.org/lkml/20220429172030.398011-5-j.neuschaefer@gmx.net/ - Various improvements, suggested by Krzysztof Kozlowski v1: - https://lore.kernel.org/lkml/20220422183012.444674-5-j.neuschaefer@gmx.net/ --- .../bindings/clock/nuvoton,wpcm450-clk.yaml | 65 ++++++++++++++++++ .../dt-bindings/clock/nuvoton,wpcm450-clk.h | 67 +++++++++++++++++++ 2 files changed, 132 insertions(+) create mode 100644 Documentation/devicetree/bindings/clock/nuvoton,wpcm450-clk.yaml create mode 100644 include/dt-bindings/clock/nuvoton,wpcm450-clk.h -- 2.40.1 diff --git a/Documentation/devicetree/bindings/clock/nuvoton,wpcm450-clk.yaml b/Documentation/devicetree/bindings/clock/nuvoton,wpcm450-clk.yaml new file mode 100644 index 0000000000000..93521cf68a040 --- /dev/null +++ b/Documentation/devicetree/bindings/clock/nuvoton,wpcm450-clk.yaml @@ -0,0 +1,65 @@ +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) +%YAML 1.2 +--- +$id: http://devicetree.org/schemas/clock/nuvoton,wpcm450-clk.yaml# +$schema: http://devicetree.org/meta-schemas/core.yaml# + +title: Nuvoton WPCM450 clock controller + +maintainers: + - Jonathan Neuschäfer + +description: + The clock controller of the Nuvoton WPCM450 SoC supplies clocks and resets to + the rest of the chip. + +properties: + compatible: + const: nuvoton,wpcm450-clk + + reg: + maxItems: 1 + + clocks: + items: + - description: Reference clock oscillator (should be 48 MHz) + + clock-names: + items: + - const: ref + + '#clock-cells': + const: 1 + + '#reset-cells': + const: 1 + +additionalProperties: false + +required: + - compatible + - reg + - clocks + - clock-names + - '#clock-cells' + +examples: + - | + #include + #include + + refclk: clock-48mhz { + /* 48 MHz reference oscillator */ + compatible = "fixed-clock"; + clock-frequency = <48000000>; + #clock-cells = <0>; + }; + + clk: clock-controller@b0000200 { + reg = <0xb0000200 0x100>; + compatible = "nuvoton,wpcm450-clk"; + clocks = <&refclk>; + clock-names = "ref"; + #clock-cells = <1>; + #reset-cells = <1>; + }; diff --git a/include/dt-bindings/clock/nuvoton,wpcm450-clk.h b/include/dt-bindings/clock/nuvoton,wpcm450-clk.h new file mode 100644 index 0000000000000..86e1c895921b7 --- /dev/null +++ b/include/dt-bindings/clock/nuvoton,wpcm450-clk.h @@ -0,0 +1,67 @@ +/* SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) */ + +#ifndef _DT_BINDINGS_CLOCK_NUVOTON_WPCM450_CLK_H +#define _DT_BINDINGS_CLOCK_NUVOTON_WPCM450_CLK_H + +/* Clocks based on CLKEN bits */ +#define WPCM450_CLK_FIU 0 +#define WPCM450_CLK_XBUS 1 +#define WPCM450_CLK_KCS 2 +#define WPCM450_CLK_SHM 4 +#define WPCM450_CLK_USB1 5 +#define WPCM450_CLK_EMC0 6 +#define WPCM450_CLK_EMC1 7 +#define WPCM450_CLK_USB0 8 +#define WPCM450_CLK_PECI 9 +#define WPCM450_CLK_AES 10 +#define WPCM450_CLK_UART0 11 +#define WPCM450_CLK_UART1 12 +#define WPCM450_CLK_SMB2 13 +#define WPCM450_CLK_SMB3 14 +#define WPCM450_CLK_SMB4 15 +#define WPCM450_CLK_SMB5 16 +#define WPCM450_CLK_HUART 17 +#define WPCM450_CLK_PWM 18 +#define WPCM450_CLK_TIMER0 19 +#define WPCM450_CLK_TIMER1 20 +#define WPCM450_CLK_TIMER2 21 +#define WPCM450_CLK_TIMER3 22 +#define WPCM450_CLK_TIMER4 23 +#define WPCM450_CLK_MFT0 24 +#define WPCM450_CLK_MFT1 25 +#define WPCM450_CLK_WDT 26 +#define WPCM450_CLK_ADC 27 +#define WPCM450_CLK_SDIO 28 +#define WPCM450_CLK_SSPI 29 +#define WPCM450_CLK_SMB0 30 +#define WPCM450_CLK_SMB1 31 + +/* Other clocks */ +#define WPCM450_CLK_USBPHY 32 + +#define WPCM450_NUM_CLKS 33 + +/* Resets based on IPSRST bits */ +#define WPCM450_RESET_FIU 0 +#define WPCM450_RESET_EMC0 6 +#define WPCM450_RESET_EMC1 7 +#define WPCM450_RESET_USB0 8 +#define WPCM450_RESET_USB1 9 +#define WPCM450_RESET_AES_PECI 10 +#define WPCM450_RESET_UART 11 +#define WPCM450_RESET_MC 12 +#define WPCM450_RESET_SMB2 13 +#define WPCM450_RESET_SMB3 14 +#define WPCM450_RESET_SMB4 15 +#define WPCM450_RESET_SMB5 16 +#define WPCM450_RESET_PWM 18 +#define WPCM450_RESET_TIMER 19 +#define WPCM450_RESET_ADC 27 +#define WPCM450_RESET_SDIO 28 +#define WPCM450_RESET_SSPI 29 +#define WPCM450_RESET_SMB0 30 +#define WPCM450_RESET_SMB1 31 + +#define WPCM450_NUM_RESETS 32 + +#endif /* _DT_BINDINGS_CLOCK_NUVOTON_WPCM450_CLK_H */ From patchwork Sat Sep 23 14:34:37 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?J=2E_Neusch=C3=A4fer?= X-Patchwork-Id: 725625 Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A89FE2FB2 for ; Sat, 23 Sep 2023 14:35:19 +0000 (UTC) Received: from mout.gmx.net (mout.gmx.net [212.227.17.22]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A1F80136; Sat, 23 Sep 2023 07:35:16 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gmx.net; s=s31663417; t=1695479685; x=1696084485; i=j.neuschaefer@gmx.net; bh=AWu2JIQ2eEUreKlgs/1K7W1DpBjaukkQaZGcD3bxik0=; h=X-UI-Sender-Class:From:To:Cc:Subject:Date:In-Reply-To:References; b=RPrgq7JvbozdTCvOzIiNzHoXBMhiNAXJxR8xh1sfwVo4W55kutrWL7VHEG265jR3zeZP1TG08gH quMw5/EfnhWJQ0zT0qLuEsMa1AMzJnnk6Z03IHUcj48625vOXUzE0mMgmv3zZS7xgS2R55nOsOltK 9ekwpWrZoCHQd5tQJwKCOacctQh1ulFBRTCEZ6SGKUNwX7yZHcGXj76TyiRIT+G9BF2kfMVRYvPKT L5j9c78l7+HOsmc1FmET8TR9j3wdE2qkGmpGJKE6/zqES1pe43peAAqRmHSxbGY5fDq8p5g9dXqTW CdoMsNnzGQxYjUGkKaf6xyp75z8pMdn3RF7w== X-UI-Sender-Class: 724b4f7f-cbec-4199-ad4e-598c01a50d3a Received: from probook ([89.0.47.152]) by mail.gmx.net (mrgmx104 [212.227.17.168]) with ESMTPSA (Nemesis) id 1N1Obb-1rgwdr3FJj-012sd2; Sat, 23 Sep 2023 16:34:44 +0200 From: =?utf-8?q?Jonathan_Neusch=C3=A4fer?= To: linux-clk@vger.kernel.org, openbmc@lists.ozlabs.org Cc: linux-kernel@vger.kernel.org, linux-watchdog@vger.kernel.org, devicetree@vger.kernel.org, =?utf-8?q?Jonathan_Neusch=C3=A4fer?= , Michael Turquette , Stephen Boyd , Rob Herring , Krzysztof Kozlowski , Avi Fishman , Tomer Maimon , Tali Perry , Patrick Venture , Nancy Yuen , Benjamin Fair , Daniel Lezcano , Thomas Gleixner , Philipp Zabel , Wim Van Sebroeck , Guenter Roeck , Christophe JAILLET , Conor Dooley Subject: [PATCH v9 2/3] ARM: dts: wpcm450: Remove clock-output-names from reference clock node Date: Sat, 23 Sep 2023 16:34:37 +0200 Message-Id: <20230923143438.1895461-3-j.neuschaefer@gmx.net> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20230923143438.1895461-1-j.neuschaefer@gmx.net> References: <20230923143438.1895461-1-j.neuschaefer@gmx.net> Precedence: bulk X-Mailing-List: devicetree@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Provags-ID: V03:K1:fZTP3iEedJx5jU6DD2233C/N9kQ3S1oI5FemAJqETR2hK93qaPY c+9OBtrH1jgBy7W+xap7l2CQ3fkM3nJurats90HJ22XHW1SJTb0R94nraV6wzSGrfNz4MOc Oj8+aKP6cneQfBBxiOLZo97NOwuXXqembW/9fiWU5eS6+gkK/fUi4fC2x8pbLShkf/b6O+4 QrwifuTszaMUwQP3tpDwA== UI-OutboundReport: notjunk:1;M01:P0:gxIcBNTOonc=;MYBE4x++C3AM5pYcNl+vVbUgDS7 ++fUU3YZrng3P2s33M2M/JmBW4KCS7NgR2y7XjYffv+5HFebRfa5Z/2lUiz8ZEjg7CTsW2rlm Hv9HVnDbzdFv25Nju0hnCywKVztposB4m/4vMsKJKpzla9RAH64vZAJvfGr2U5b1amuC6cGP/ FIEY+TQDu1tXfjyidMdHFcSA9LcYqB8ubR6TGJSyMzD2PDexMG8y6e9RyyQqP28tRVzoldtrr reoENad3bqouU86MXFpCMx3k8OdWvwvXCr6sYoscpyyIShGMhBa87naW+ogYCbuDMiE+BEZPt PGpyEqTueuQ8QotqkxbIrsJA1mGrBnPoD5OGKYHCeZ2HafgPQVejTQjo57gTIsrmZx6a7ImS4 +VjsrOSyo70qiccEDrMp+fpUKNxk7ADQO+zSZjORwJ1iINm96UBvPDk+PWjw6GihkaqSgW1Wx e7Ep/fUQu0h32/SdUfEPLusO8v67VIH4VoPkl96QIcSnHIk3eCxQzAU3d1qOJwa/woBAqW1iD opgAX2TigJD+p5FQpFXfV/9x/t3yOAN2fscM8idCj4+3wTTCz3rj4VgQj/yWrQf6quqfeWTxD ZKLiDsZK3yA8ujOGVwr2gsOShQ48q40p3hsydme3OO0XmK06S6AtcJLmOLq23mG9x8Pbh+X5a Q2uzPSf3NUCxKd04IqgmGXXcR2puBsHJ9Ui//pAuKJULxfWimDnYSL/0+aKFO9v4XNn8QEkm8 v9OynfFsjdO+YRsM20dY5q1g/wUCj4t7AmZnkMH03oXAbvce1SQyKp20aDEj2uzuzPvk0MaTm GfkH6TqltSqvK5K/Cw5YkAEHF3mJtMGFEGbzNkleHd8N8kjEpQXeKwY7PWUmAN4g7dXohgWim 21FmuS19smXTpYDlBV5L7NbN3TSIxIEU0ySHwp6nYVjmkv6I+nP6K9X39jT+pnpY5Bd/6AaLe 9P6oCCuAXD2HxhLDmdWq1nAEP14= X-Spam-Status: No, score=-2.1 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,FREEMAIL_FROM, RCVD_IN_DNSWL_BLOCKED,RCVD_IN_MSPIKE_H3,RCVD_IN_MSPIKE_WL, SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net This is not necessary anymore, because the clk-wpcm450 driver doesn't rely on global clock names anymore. Signed-off-by: Jonathan Neuschäfer --- v9: - New patch --- arch/arm/boot/dts/nuvoton/nuvoton-wpcm450.dtsi | 1 - 1 file changed, 1 deletion(-) -- 2.40.1 diff --git a/arch/arm/boot/dts/nuvoton/nuvoton-wpcm450.dtsi b/arch/arm/boot/dts/nuvoton/nuvoton-wpcm450.dtsi index fd671c7a1e5d6..b7d9b9ebdb1e2 100644 --- a/arch/arm/boot/dts/nuvoton/nuvoton-wpcm450.dtsi +++ b/arch/arm/boot/dts/nuvoton/nuvoton-wpcm450.dtsi @@ -40,7 +40,6 @@ clk24m: clock-24mhz { refclk: clock-48mhz { /* 48 MHz reference oscillator */ compatible = "fixed-clock"; - clock-output-names = "ref"; clock-frequency = <48000000>; #clock-cells = <0>; }; From patchwork Sat Sep 23 14:34:38 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?J=2E_Neusch=C3=A4fer?= X-Patchwork-Id: 725624 Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id B314615E87 for ; Sat, 23 Sep 2023 14:35:24 +0000 (UTC) Received: from mout.gmx.net (mout.gmx.net [212.227.17.20]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 05E2411D; Sat, 23 Sep 2023 07:35:21 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gmx.net; s=s31663417; t=1695479690; x=1696084490; i=j.neuschaefer@gmx.net; bh=T2d2ejbC2mALJ1U6tDhz01Ee1erBfjfOArAZEVtwdSM=; h=X-UI-Sender-Class:From:To:Cc:Subject:Date:In-Reply-To:References; b=Q2eakrtcpDQweTLovOKQJ7ZeYGjb/X9QM2/T08dJrPf6N7Q27mGRxyBe/bGvGv/U7h/3EV5uWvD 2L18ji5A59PjThkLHsVE89Tw7uynN9jiJTYpJ4UqFhimRstEsigAnM6GD6saUMtfaHbBIXFHOdXGH oyFJuCnsmdmGHxcn6AZ9L/WR9/p0J8ebbxd19o9g41SM27KTd+cg2JaB+WgiPyFNqciDkBPkH1jt/ mzJZPomlKT21V58QZeV8oHVYTLvZVH85tiQVQ7b9NY1NY4yJAuEIFJygsQOhYOak2uXmFndnybEVu IlUzI1ExDpUzDgNz69w+UBkaCRUzSOfgk1IQ== X-UI-Sender-Class: 724b4f7f-cbec-4199-ad4e-598c01a50d3a Received: from probook ([89.0.47.152]) by mail.gmx.net (mrgmx104 [212.227.17.168]) with ESMTPSA (Nemesis) id 1Mnaof-1rR3Ns3DQz-00jZSD; Sat, 23 Sep 2023 16:34:49 +0200 From: =?utf-8?q?Jonathan_Neusch=C3=A4fer?= To: linux-clk@vger.kernel.org, openbmc@lists.ozlabs.org Cc: linux-kernel@vger.kernel.org, linux-watchdog@vger.kernel.org, devicetree@vger.kernel.org, =?utf-8?q?Jonathan_Neusch=C3=A4fer?= , Michael Turquette , Stephen Boyd , Rob Herring , Krzysztof Kozlowski , Avi Fishman , Tomer Maimon , Tali Perry , Patrick Venture , Nancy Yuen , Benjamin Fair , Daniel Lezcano , Thomas Gleixner , Philipp Zabel , Wim Van Sebroeck , Guenter Roeck , Christophe JAILLET , Conor Dooley , Joel Stanley , Arnd Bergmann , Jacky Huang , Krzysztof Kozlowski Subject: [PATCH v9 3/3] clk: wpcm450: Add Nuvoton WPCM450 clock/reset controller driver Date: Sat, 23 Sep 2023 16:34:38 +0200 Message-Id: <20230923143438.1895461-4-j.neuschaefer@gmx.net> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20230923143438.1895461-1-j.neuschaefer@gmx.net> References: <20230923143438.1895461-1-j.neuschaefer@gmx.net> Precedence: bulk X-Mailing-List: devicetree@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Provags-ID: V03:K1:UDDiR30UDZZs70KEcWs0C8jVpVZQYYM940C3cIHqDAN+YQWOPtf gY/tilJ5b9uUWidZ764dbvdI+EBPG/LK8hA80F4l9YuMVklay2VGokoXE6BiQwdSE095SWj YKYDxAuqi6JMQgpRqXjUyPgQ6JQ28c6d1RQVw0R5ptV2EemXKhk4zBQIvfiCxkJo/Fduj85 ad1Zj4u+ZxKnvssVX2IqA== UI-OutboundReport: notjunk:1;M01:P0:h0IUv0SRo+s=;ZBjKZJeclrMsHqw96CLJGaEN4RX tHbs5zuUzqABWow0cicgsQqtsA78KhGUwWk6TKuwpmzX+5mzA7zqBtjcGAGQhcBZELYBZchqb NbqTcRMk+apnK9AsycvvIJTYtImqElSKoINYQeVhP5JK3P8Yx260vv/E8G06dzHiddUgfUI5O oawJ+9Bo/e8xPp4MyjCc6dzmVjaDDmC/r2nbVUsf+2ueELRe8mp+H86mkZrbgCq6uLo1DCi9C Ayn6BzsBdSP6Wws1fIV3tL1R7Ba82Nu5B+yTRkix8ORgS3BxSk7OdaqtMD9IbXlBMA1RrtX6J v+zpvHsvYpelmSo5U6TiSxvVlLdrLWgjFBnPM7ZwQZOGs7NA9rSYuaNsY+/8RKcqv3o1KTcVO q7Yx79fmbwzIW5Jm5yyjNFLUh/b4FLrCOhu37JeTIWfZusz9oKsqdTP9glTBzGE5CeZVXFFRP CTIj8Ek6GPMbuU0NjcG0zDFkGJUKTaJxo0UH2TeQq4rYV79htn11AGqnXwXAq5HDvEOlUaaxV ZUJByUTa6vtOPekR2zGWdUYqc06bLPiXhI1TDNFlwqwlOqX2a13fwtJjUxjCJ2+pbslKHeD95 IfxWTuJU8GvWLbz7FJorjq03KOwMcwWpUtLF6q+tJGu3owxBTfgi6Lod+C+Gaq5QOfYDg4BUH QC0HHTDmofQ4YP2dMDXNeSKiZZEnjK94Puq+sVBXqHuZv5vi8VzpdNCl/mv247M61zVujtzNg 7DW6NnhLeaF+WoJgU/FKYr6C2ZEYXH6pRFwYIvDFKo9eGYZ5DYRTMmYqWKS/ONMMS/h540s83 sEDq/rS4smQlTVNqFssYVI+dVdeQ0LEb34zQ70Sh3iHVpHff8JKXEt5kupCmJluaSlxONEcHT 4oN7WwnCHJD9kqAXe17V9PaRqmiwJ0+uNJWAveBgiMiJL1HdtuHX91w0Mm1xG2zYvR/fPTqHf TwTuCcKuGZwKweVZOpuhxalSEpY= X-Spam-Status: No, score=-2.1 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,FREEMAIL_FROM, RCVD_IN_DNSWL_BLOCKED,RCVD_IN_MSPIKE_H4,RCVD_IN_MSPIKE_WL, SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net This driver implements the following features w.r.t. the clock and reset controller in the WPCM450 SoC: - It calculates the rates for all clocks managed by the clock controller - It leaves the clock tree mostly unchanged, except that it enables/ disables clock gates based on usage. - It exposes the reset lines managed by the controller using the Generic Reset Controller subsystem NOTE: If the driver and the corresponding devicetree node are present, the driver will disable "unused" clocks. This is problem until the clock relations are properly declared in the devicetree (in a later patch). Until then, the clk_ignore_unused kernel parameter can be used as a workaround. Signed-off-by: Jonathan Neuschäfer Reviewed-by: Joel Stanley --- I have considered converting this driver to a platform driver instead of using CLK_OF_DECLARE, because platform drivers are generally the way forward. However, the timer-npcm7xx driver used on the same platform requires is initialized with TIMER_OF_DECLARE and thus requires the clocks to be available earlier than a platform driver can provide them. v9: - Apply comments made by Stephen Boyd - Move to drivers/clk/nuvoton/ directory - Update SPDX license identifier from GPL-2.0 to GPL-2.0-only - Rename clk_np variable to np - Use of_clk_hw_register - Refer to clock parents by .fw_name v8: - https://lore.kernel.org/lkml/20230428190226.1304326-3-j.neuschaefer@gmx.net/ - Use %pe format specifier throughout the driver, as suggested by Philipp Zabel - Add Joel's R-b v7: - https://lore.kernel.org/lkml/20230422220240.322572-3-j.neuschaefer@gmx.net/ - Simplify error handling by not deallocating resources v6: - Enable RESET_SIMPLE based on ARCH_WPCM450, not ARCH_NPCM, as suggested by Tomer Maimon v5: - https://lore.kernel.org/lkml/20221104161850.2889894-6-j.neuschaefer@gmx.net/ - Switch to using clk_parent_data v4: - Fix reset controller initialization v3: - Change reference clock name from "refclk" to "ref" - Remove unused variable in return path of wpcm450_clk_register_pll - Remove unused divisor tables v2: - no changes --- drivers/clk/Makefile | 2 +- drivers/clk/nuvoton/Kconfig | 8 +- drivers/clk/nuvoton/Makefile | 1 + drivers/clk/nuvoton/clk-wpcm450.c | 372 ++++++++++++++++++++++++++++++ drivers/reset/Kconfig | 2 +- 5 files changed, 382 insertions(+), 3 deletions(-) create mode 100644 drivers/clk/nuvoton/clk-wpcm450.c -- 2.40.1 diff --git a/drivers/clk/Makefile b/drivers/clk/Makefile index 18969cbd4bb1e..de51182ef630d 100644 --- a/drivers/clk/Makefile +++ b/drivers/clk/Makefile @@ -106,7 +106,7 @@ endif obj-y += mstar/ obj-y += mvebu/ obj-$(CONFIG_ARCH_MXS) += mxs/ -obj-$(CONFIG_ARCH_MA35) += nuvoton/ +obj-y += nuvoton/ obj-$(CONFIG_COMMON_CLK_NXP) += nxp/ obj-$(CONFIG_COMMON_CLK_PISTACHIO) += pistachio/ obj-$(CONFIG_COMMON_CLK_PXA) += pxa/ diff --git a/drivers/clk/nuvoton/Kconfig b/drivers/clk/nuvoton/Kconfig index fe4b7f62f4670..22c5ab409d235 100644 --- a/drivers/clk/nuvoton/Kconfig +++ b/drivers/clk/nuvoton/Kconfig @@ -3,7 +3,7 @@ config COMMON_CLK_NUVOTON bool "Nuvoton clock controller common support" - depends on ARCH_MA35 || COMPILE_TEST + depends on ARCH_MA35 || ARCH_NPCM || COMPILE_TEST default y help Say y here to enable common clock controller for Nuvoton platforms. @@ -16,4 +16,10 @@ config CLK_MA35D1 help Build the clock controller driver for MA35D1 SoC. +config CLK_WPCM450 + bool "Nuvoton WPCM450 clock/reset controller support" + default y + help + Build the clock and reset controller driver for the WPCM450 SoC. + endif diff --git a/drivers/clk/nuvoton/Makefile b/drivers/clk/nuvoton/Makefile index c3c59dd9f2aaa..b130f0d3889ca 100644 --- a/drivers/clk/nuvoton/Makefile +++ b/drivers/clk/nuvoton/Makefile @@ -2,3 +2,4 @@ obj-$(CONFIG_CLK_MA35D1) += clk-ma35d1.o obj-$(CONFIG_CLK_MA35D1) += clk-ma35d1-divider.o obj-$(CONFIG_CLK_MA35D1) += clk-ma35d1-pll.o +obj-$(CONFIG_CLK_WPCM450) += clk-wpcm450.o diff --git a/drivers/clk/nuvoton/clk-wpcm450.c b/drivers/clk/nuvoton/clk-wpcm450.c new file mode 100644 index 0000000000000..9100c4b8a5648 --- /dev/null +++ b/drivers/clk/nuvoton/clk-wpcm450.c @@ -0,0 +1,372 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Nuvoton WPCM450 clock and reset controller driver. + * + * Copyright (C) 2022 Jonathan Neuschäfer + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include + +struct wpcm450_clk_pll { + struct clk_hw hw; + void __iomem *pllcon; + u8 flags; +}; + +#define to_wpcm450_clk_pll(_hw) container_of(_hw, struct wpcm450_clk_pll, hw) + +#define PLLCON_FBDV GENMASK(24, 16) +#define PLLCON_PRST BIT(13) +#define PLLCON_PWDEN BIT(12) +#define PLLCON_OTDV GENMASK(10, 8) +#define PLLCON_INDV GENMASK(5, 0) + +static unsigned long wpcm450_clk_pll_recalc_rate(struct clk_hw *hw, + unsigned long parent_rate) +{ + struct wpcm450_clk_pll *pll = to_wpcm450_clk_pll(hw); + unsigned long fbdv, indv, otdv; + u64 rate; + u32 pllcon; + + if (parent_rate == 0) + return 0; + + pllcon = readl_relaxed(pll->pllcon); + + indv = FIELD_GET(PLLCON_INDV, pllcon) + 1; + fbdv = FIELD_GET(PLLCON_FBDV, pllcon) + 1; + otdv = FIELD_GET(PLLCON_OTDV, pllcon) + 1; + + rate = (u64)parent_rate * fbdv; + do_div(rate, indv * otdv); + + return rate; +} + +static int wpcm450_clk_pll_is_enabled(struct clk_hw *hw) +{ + struct wpcm450_clk_pll *pll = to_wpcm450_clk_pll(hw); + u32 pllcon; + + pllcon = readl_relaxed(pll->pllcon); + + return !(pllcon & PLLCON_PRST); +} + +static void wpcm450_clk_pll_disable(struct clk_hw *hw) +{ + struct wpcm450_clk_pll *pll = to_wpcm450_clk_pll(hw); + u32 pllcon; + + pllcon = readl_relaxed(pll->pllcon); + pllcon |= PLLCON_PRST | PLLCON_PWDEN; + writel(pllcon, pll->pllcon); +} + +static const struct clk_ops wpcm450_clk_pll_ops = { + .recalc_rate = wpcm450_clk_pll_recalc_rate, + .is_enabled = wpcm450_clk_pll_is_enabled, + .disable = wpcm450_clk_pll_disable +}; + +static struct clk_hw * +wpcm450_clk_register_pll(struct device_node *np, void __iomem *pllcon, const char *name, + const struct clk_parent_data *parent, unsigned long flags) +{ + struct wpcm450_clk_pll *pll; + struct clk_init_data init = {}; + int ret; + + pll = kzalloc(sizeof(*pll), GFP_KERNEL); + if (!pll) + return ERR_PTR(-ENOMEM); + + init.name = name; + init.ops = &wpcm450_clk_pll_ops; + init.parent_data = parent; + init.num_parents = 1; + init.flags = flags; + + pll->pllcon = pllcon; + pll->hw.init = &init; + + ret = of_clk_hw_register(np, &pll->hw); + if (ret) { + kfree(pll); + return ERR_PTR(ret); + } + + return &pll->hw; +} + +#define REG_CLKEN 0x00 +#define REG_CLKSEL 0x04 +#define REG_CLKDIV 0x08 +#define REG_PLLCON0 0x0c +#define REG_PLLCON1 0x10 +#define REG_PMCON 0x14 +#define REG_IRQWAKECON 0x18 +#define REG_IRQWAKEFLAG 0x1c +#define REG_IPSRST 0x20 + +struct wpcm450_pll_data { + const char *name; + struct clk_parent_data parent; + unsigned int reg; + unsigned long flags; +}; + +static const struct wpcm450_pll_data pll_data[] = { + { "pll0", { .fw_name = "ref" }, REG_PLLCON0, 0 }, + { "pll1", { .fw_name = "ref" }, REG_PLLCON1, 0 }, +}; + +struct wpcm450_clksel_data { + const char *name; + const struct clk_parent_data *parents; + unsigned int num_parents; + const u32 *table; + int shift; + int width; + int index; + unsigned long flags; +}; + +static const u32 parent_table[] = { 0, 1, 2 }; + +static const struct clk_parent_data default_parents[] = { + { .name = "pll0" }, + { .name = "pll1" }, + { .name = "ref" }, +}; + +static const struct clk_parent_data huart_parents[] = { + { .fw_name = "ref" }, + { .name = "refdiv2" }, +}; + +static const struct wpcm450_clksel_data clksel_data[] = { + { "cpusel", default_parents, ARRAY_SIZE(default_parents), + parent_table, 0, 2, -1, CLK_IS_CRITICAL }, + { "clkout", default_parents, ARRAY_SIZE(default_parents), + parent_table, 2, 2, -1, 0 }, + { "usbphy", default_parents, ARRAY_SIZE(default_parents), + parent_table, 6, 2, -1, 0 }, + { "uartsel", default_parents, ARRAY_SIZE(default_parents), + parent_table, 8, 2, WPCM450_CLK_USBPHY, 0 }, + { "huartsel", huart_parents, ARRAY_SIZE(huart_parents), + parent_table, 10, 1, -1, 0 }, +}; + +static const struct clk_div_table div_fixed2[] = { + { .val = 0, .div = 2 }, + { } +}; + +struct wpcm450_clkdiv_data { + const char *name; + struct clk_parent_data parent; + int div_flags; + const struct clk_div_table *table; + int shift; + int width; + unsigned long flags; +}; + +static struct wpcm450_clkdiv_data clkdiv_data_early[] = { + { "refdiv2", { .name = "ref" }, 0, div_fixed2, 0, 0 }, +}; + +static const struct wpcm450_clkdiv_data clkdiv_data[] = { + { "cpu", { .name = "cpusel" }, 0, div_fixed2, 0, 0, CLK_IS_CRITICAL }, + { "adcdiv", { .name = "ref" }, CLK_DIVIDER_POWER_OF_TWO, NULL, 28, 2, 0 }, + { "apb", { .name = "ahb" }, CLK_DIVIDER_POWER_OF_TWO, NULL, 26, 2, 0 }, + { "ahb", { .name = "cpu" }, CLK_DIVIDER_POWER_OF_TWO, NULL, 24, 2, 0 }, + { "uart", { .name = "uartsel" }, 0, NULL, 16, 4, 0 }, + { "ahb3", { .name = "ahb" }, CLK_DIVIDER_POWER_OF_TWO, NULL, 8, 2, 0 }, +}; + +struct wpcm450_clken_data { + const char *name; + struct clk_parent_data parent; + int bitnum; + unsigned long flags; +}; + +static const struct wpcm450_clken_data clken_data[] = { + { "fiu", { .name = "ahb3" }, WPCM450_CLK_FIU, 0 }, + { "xbus", { .name = "ahb3" }, WPCM450_CLK_XBUS, 0 }, + { "kcs", { .name = "apb" }, WPCM450_CLK_KCS, 0 }, + { "shm", { .name = "ahb3" }, WPCM450_CLK_SHM, 0 }, + { "usb1", { .name = "ahb" }, WPCM450_CLK_USB1, 0 }, + { "emc0", { .name = "ahb" }, WPCM450_CLK_EMC0, 0 }, + { "emc1", { .name = "ahb" }, WPCM450_CLK_EMC1, 0 }, + { "usb0", { .name = "ahb" }, WPCM450_CLK_USB0, 0 }, + { "peci", { .name = "apb" }, WPCM450_CLK_PECI, 0 }, + { "aes", { .name = "apb" }, WPCM450_CLK_AES, 0 }, + { "uart0", { .name = "uart" }, WPCM450_CLK_UART0, 0 }, + { "uart1", { .name = "uart" }, WPCM450_CLK_UART1, 0 }, + { "smb2", { .name = "apb" }, WPCM450_CLK_SMB2, 0 }, + { "smb3", { .name = "apb" }, WPCM450_CLK_SMB3, 0 }, + { "smb4", { .name = "apb" }, WPCM450_CLK_SMB4, 0 }, + { "smb5", { .name = "apb" }, WPCM450_CLK_SMB5, 0 }, + { "huart", { .name = "huartsel" }, WPCM450_CLK_HUART, 0 }, + { "pwm", { .name = "apb" }, WPCM450_CLK_PWM, 0 }, + { "timer0", { .name = "refdiv2" }, WPCM450_CLK_TIMER0, 0 }, + { "timer1", { .name = "refdiv2" }, WPCM450_CLK_TIMER1, 0 }, + { "timer2", { .name = "refdiv2" }, WPCM450_CLK_TIMER2, 0 }, + { "timer3", { .name = "refdiv2" }, WPCM450_CLK_TIMER3, 0 }, + { "timer4", { .name = "refdiv2" }, WPCM450_CLK_TIMER4, 0 }, + { "mft0", { .name = "apb" }, WPCM450_CLK_MFT0, 0 }, + { "mft1", { .name = "apb" }, WPCM450_CLK_MFT1, 0 }, + { "wdt", { .name = "refdiv2" }, WPCM450_CLK_WDT, 0 }, + { "adc", { .name = "adcdiv" }, WPCM450_CLK_ADC, 0 }, + { "sdio", { .name = "ahb" }, WPCM450_CLK_SDIO, 0 }, + { "sspi", { .name = "apb" }, WPCM450_CLK_SSPI, 0 }, + { "smb0", { .name = "apb" }, WPCM450_CLK_SMB0, 0 }, + { "smb1", { .name = "apb" }, WPCM450_CLK_SMB1, 0 }, +}; + +static DEFINE_SPINLOCK(wpcm450_clk_lock); + +/* + * NOTE: Error handling is very rudimentary here. If the clock driver initial- + * ization fails, the system is probably in bigger trouble than what is caused + * by a few leaked resources. + */ + +static void __init wpcm450_clk_init(struct device_node *np) +{ + struct clk_hw_onecell_data *clk_data; + static struct clk_hw **hws; + static struct clk_hw *hw; + void __iomem *clk_base; + int i, ret; + struct reset_simple_data *reset; + + clk_base = of_iomap(np, 0); + if (!clk_base) { + pr_err("%pOFP: failed to map registers\n", np); + of_node_put(np); + return; + } + of_node_put(np); + + clk_data = kzalloc(struct_size(clk_data, hws, WPCM450_NUM_CLKS), GFP_KERNEL); + if (!clk_data) + return; + + clk_data->num = WPCM450_NUM_CLKS; + hws = clk_data->hws; + + for (i = 0; i < WPCM450_NUM_CLKS; i++) + hws[i] = ERR_PTR(-ENOENT); + + /* PLLs */ + for (i = 0; i < ARRAY_SIZE(pll_data); i++) { + const struct wpcm450_pll_data *data = &pll_data[i]; + + hw = wpcm450_clk_register_pll(np, clk_base + data->reg, data->name, + &data->parent, data->flags); + if (IS_ERR(hw)) { + pr_info("Failed to register PLL: %pe\n", hw); + return; + } + } + + /* Early divisors (REF/2) */ + for (i = 0; i < ARRAY_SIZE(clkdiv_data_early); i++) { + const struct wpcm450_clkdiv_data *data = &clkdiv_data_early[i]; + + hw = clk_hw_register_divider_table_parent_data(NULL, data->name, &data->parent, + data->flags, clk_base + REG_CLKDIV, + data->shift, data->width, + data->div_flags, data->table, + &wpcm450_clk_lock); + if (IS_ERR(hw)) { + pr_err("Failed to register div table: %pe\n", hw); + return; + } + } + + /* Selects/muxes */ + for (i = 0; i < ARRAY_SIZE(clksel_data); i++) { + const struct wpcm450_clksel_data *data = &clksel_data[i]; + + hw = clk_hw_register_mux_parent_data(NULL, data->name, data->parents, + data->num_parents, data->flags, + clk_base + REG_CLKSEL, data->shift, + data->width, 0, + &wpcm450_clk_lock); + if (IS_ERR(hw)) { + pr_err("Failed to register mux: %pe\n", hw); + return; + } + if (data->index >= 0) + clk_data->hws[data->index] = hw; + } + + /* Divisors */ + for (i = 0; i < ARRAY_SIZE(clkdiv_data); i++) { + const struct wpcm450_clkdiv_data *data = &clkdiv_data[i]; + + hw = clk_hw_register_divider_table_parent_data(NULL, data->name, &data->parent, + data->flags, clk_base + REG_CLKDIV, + data->shift, data->width, + data->div_flags, data->table, + &wpcm450_clk_lock); + if (IS_ERR(hw)) { + pr_err("Failed to register divider: %pe\n", hw); + return; + } + } + + /* Enables/gates */ + for (i = 0; i < ARRAY_SIZE(clken_data); i++) { + const struct wpcm450_clken_data *data = &clken_data[i]; + + hw = clk_hw_register_gate_parent_data(NULL, data->name, &data->parent, data->flags, + clk_base + REG_CLKEN, data->bitnum, + data->flags, &wpcm450_clk_lock); + if (IS_ERR(hw)) { + pr_err("Failed to register gate: %pe\n", hw); + return; + } + clk_data->hws[data->bitnum] = hw; + } + + ret = of_clk_add_hw_provider(np, of_clk_hw_onecell_get, clk_data); + if (ret) + pr_err("Failed to add DT provider: %pe\n", ERR_PTR(ret)); + + /* Reset controller */ + reset = kzalloc(sizeof(*reset), GFP_KERNEL); + if (!reset) + return; + reset->rcdev.owner = THIS_MODULE; + reset->rcdev.nr_resets = WPCM450_NUM_RESETS; + reset->rcdev.ops = &reset_simple_ops; + reset->rcdev.of_node = np; + reset->membase = clk_base + REG_IPSRST; + ret = reset_controller_register(&reset->rcdev); + if (ret) + pr_err("Failed to register reset controller: %pe\n", ERR_PTR(ret)); + + of_node_put(np); +} + +CLK_OF_DECLARE(wpcm450_clk_init, "nuvoton,wpcm450-clk", wpcm450_clk_init); diff --git a/drivers/reset/Kconfig b/drivers/reset/Kconfig index ccd59ddd76100..1975e2f2e9e84 100644 --- a/drivers/reset/Kconfig +++ b/drivers/reset/Kconfig @@ -213,7 +213,7 @@ config RESET_SCMI config RESET_SIMPLE bool "Simple Reset Controller Driver" if COMPILE_TEST || EXPERT - default ARCH_ASPEED || ARCH_BCMBCA || ARCH_BITMAIN || ARCH_REALTEK || ARCH_STM32 || (ARCH_INTEL_SOCFPGA && ARM64) || ARCH_SUNXI || ARC + default ARCH_ASPEED || ARCH_BCMBCA || ARCH_BITMAIN || ARCH_REALTEK || ARCH_STM32 || (ARCH_INTEL_SOCFPGA && ARM64) || ARCH_SUNXI || ARC || ARCH_WPCM450 depends on HAS_IOMEM help This enables a simple reset controller driver for reset lines that