From nobody Fri Nov 29 00:47:06 2024 Received: from NAM12-BN8-obe.outbound.protection.outlook.com (mail-bn8nam12on2132.outbound.protection.outlook.com [40.107.237.132]) (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 77FD5175562; Fri, 27 Sep 2024 05:25:40 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=fail smtp.client-ip=40.107.237.132 ARC-Seal: i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727414743; cv=fail; b=gMDn/MmPgwdYq+/4MpJU1gttTPQMHg9zL7fpECrVU+idRhiyvzE6Jzue8unKrb5irX1hqwY9DwJ3B7TKT8V1wyxXOADR42M72UF/cdO13eXTuLD6k03WwZUdIwCUVh0yS1ZVLT/QcEZnnFA9WxgGp9NvUAKq+x0j+T7vC5qAKKU= ARC-Message-Signature: i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727414743; c=relaxed/simple; bh=iggXLZrvO31cSQa/efuFQnc8m3BGiQEGwSczGGaVlGU=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: Content-Type:MIME-Version; b=mqhPMgl7PN1Z2wl4z66ruikzlK1KROfNSLjnQBv+n4Wctm/L1hfrjBxRP3PhUeHCQK+qx9wvHYaU5Au5NqEKzW/s+26Mo3Aq8CQocFH1rvXxxiwxJwvK9Ci5BxqOAAUNRkC5vrLWd4SWjlmjsPqJfUwxreNtUx0SeqBpPvDyuy4= ARC-Authentication-Results: i=2; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=kneron.us; spf=pass smtp.mailfrom=kneron.us; dkim=pass (1024-bit key) header.d=kneron.us header.i=@kneron.us header.b=j0/3HB82; arc=fail smtp.client-ip=40.107.237.132 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=kneron.us Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=kneron.us Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=kneron.us header.i=@kneron.us header.b="j0/3HB82" ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=t/6fRaeHJ9SUla1XMeQhp7zjOcYdTm1Tyg1ezV5ujxFy5G7eS9NkgZc/Bn0f7Mu3Efij+xpQcNQdm30HX2vQ7CU9kXRkmp+AbEMO8eM9nJVqv7fd6Cx3GcZeB0nykrZqAHS95FMoGtjbv8xyd6aw1/FkUzc2AseXRU14sbdisj3dC7BQom1dkc73eAYLAnSeVahkH48R2qog0F+h7pHK1K0+DS28HLjIhIkpfRB8cocALQLJsH66ugkKGdZIDksun4d+OLCfLEjb5XgbqVVQ3FUotz7RQIFq+vtw1MIOhO8lCdoLUUeRD/7JjUDgSeDki2WgbVgLFXdPFDelP0Vb5Q== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector10001; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-AntiSpam-MessageData-ChunkCount:X-MS-Exchange-AntiSpam-MessageData-0:X-MS-Exchange-AntiSpam-MessageData-1; bh=HfrxJmvZ/E5r0G5Euv9dngxSdBDj9xpz/WN8F/z1ciU=; b=TuTD0QATxJnJEVhazk7t+G6lgm4HmXBKnr5PQIvK9lI6iEc+iZOJDt9LRPosm5Om0TYzuKIhSqLEMR6oZ+gJ5Ve5n+XJ6qQUfkJJYv8BC0MLWkvqMuPLFXLVYw70AtXKVowP8C36XJJTxBIyWtEqCM7kG/xDJs1qUklNIwv1SKK2nVwXHqpTwPZje84Kb1DBMC1xFJiI5UhIUOq0A3m60G61OiR/4Xg1Hv7J5ZGfv6A/ETXZRDgRAvwSZYm05wd8lW0avQ3/pokN7H2NQ+fOze7al/+7Kg7cSciIDso6w4Lxq8KcZaVeaqP1WHNww8OkyBiafrQVcdZ4eoorhXH0Qg== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=kneron.us; dmarc=pass action=none header.from=kneron.us; dkim=pass header.d=kneron.us; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kneron.us; s=selector1; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=HfrxJmvZ/E5r0G5Euv9dngxSdBDj9xpz/WN8F/z1ciU=; b=j0/3HB826niGZwXiN9sE5423tZRfHlQYkLrlwSwjlU6ZUbTT3mw/m9/Z6ikmlxnOEy7PvbflCX6m1TbhEcy8GuC3N2iV3eQQ3ytDTnYe+Ra1Vul/9q20fnFgjeTnMl50n3dlt3jV+jMolpc2Pa0ISK0R3ilGp8aH9mHlnOGYfTI= Authentication-Results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=kneron.us; Received: from IA1PR14MB6224.namprd14.prod.outlook.com (2603:10b6:208:42b::6) by DM6PR14MB3449.namprd14.prod.outlook.com (2603:10b6:5:1ed::23) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.7982.28; Fri, 27 Sep 2024 05:25:37 +0000 Received: from IA1PR14MB6224.namprd14.prod.outlook.com ([fe80::c527:653c:698d:3d94]) by IA1PR14MB6224.namprd14.prod.outlook.com ([fe80::c527:653c:698d:3d94%3]) with mapi id 15.20.8005.021; Fri, 27 Sep 2024 05:25:36 +0000 From: Michael Wu To: Andi Shyti , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Jarkko Nikula , Andy Shevchenko , Mika Westerberg , Jan Dabros , linux-i2c@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Morgan Chang , mvp.kutali@gmail.com, Michael Wu Subject: [PATCH v2 2/2] i2c: dwsignware: determine HS tHIGH and tLOW based on HW parameters Date: Fri, 27 Sep 2024 12:22:17 +0800 Message-ID: <20240927042230.277144-3-michael.wu@kneron.us> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240927042230.277144-1-michael.wu@kneron.us> References: <20240927042230.277144-1-michael.wu@kneron.us> Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable X-ClientProxiedBy: TYAPR01CA0148.jpnprd01.prod.outlook.com (2603:1096:404:7e::16) To IA1PR14MB6224.namprd14.prod.outlook.com (2603:10b6:208:42b::6) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: IA1PR14MB6224:EE_|DM6PR14MB3449:EE_ X-MS-Office365-Filtering-Correlation-Id: 951e3701-48dd-4909-8dd6-08dcdeb4d14a X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|1800799024|376014|7416014|52116014|366016|921020|38350700014|80162021; X-Microsoft-Antispam-Message-Info: =?utf-8?B?N3pVQjJCR3NleVhjVXBKTG42QzZ4WHV0ZTF1aDVrQ0drMDE2QzZEaHV6cTFT?= =?utf-8?B?UWhMMWNJeEgydzVEVXlHK04zdS9jMlFvdGxTQWVFTXA2YnlZbndvODZWZGcy?= =?utf-8?B?TXV3NGtxTW03RVBMR1dpL3F5Qmp2SGxvbk1ycWJ2K3NBOGpYUTVOSWtlR2ZX?= =?utf-8?B?amV0bzdhenptWFgzbUNGSmh5VVdHMFBSSlhtekxyRnJJM28xRitBNkVDQ29N?= =?utf-8?B?QWZIRHJPRWdRMUErcldvYjRxSG5BNXp4bmtKbFl3Qm50WnlEQnhVSE95NEFF?= =?utf-8?B?V0tURXpieWVvY09IN0JWbkYyTjVYL3dBV2x2Z2VaOUNPcllVVDBLbnZZMDNF?= =?utf-8?B?aUpXNkFqUzQyaHk3OGY5WmgxaWhhZTlsSmZjVHBxblg0ZGt2YTNaWEtmeXpZ?= =?utf-8?B?VllCWlZ5Zlk0cjV3b0R3N2tCeXZVNTRxZ1laQy9oR21INVhLaGkrMWh2QUJW?= =?utf-8?B?UldmSk1RMWpMcHpwTFV5Q3EzWjlxWkFNKytEUWUyNldDUitZem9rdXgrZWM4?= =?utf-8?B?c245QXRRS0ZGMVRvQXZpd1FqNyt0S0R6L2RndzZoRmFWUUtyYWZhK0hPRHNw?= =?utf-8?B?cG44NGVtQnJyODhaU0g2clFsRDlndHorV21XbTdlY2RWSFkxeW45VXMrSm1Q?= =?utf-8?B?YUc4a1FleUptRy9QWnBDeE54WDVvdUlpbW9JNU00UTNOMnh5aXBzSFpaM2V1?= =?utf-8?B?eDFCeGp2WW5ZNFBpVnVscUNUS0llbjYyTjlPQTZuOTFBTWtycHJKUS9MM1Fo?= =?utf-8?B?d21mbnZuZ2dReWVYbHpRdGNiaG9DUy84TnQ2WFhaSnZIVUpqYTZQTWxlV0ZC?= =?utf-8?B?WDhMdktoYkttNjkyc2Fwc2dIYU9laXJNREdnZUV5dXROVGQvb0lTTW1ySzVn?= =?utf-8?B?a1BKejhhZ3FvRUNIL0diTmJKUEpkYUJtdkt1cG1rajUzZElWbjlCSkJOaGNS?= =?utf-8?B?RXlxZmRXdE9uUUhmYXhPRVRzNTdIbWNSRWFCYzFMRGRmSmxRanFlS0RwYmJl?= =?utf-8?B?UW1CeDkrdmhMMytDWnhVR1RVdnBPbE5aNUp4SUp2cyt0T3hRNWo4ckx3bXNF?= =?utf-8?B?WkE4YXJWT1ZZYXI1SjFEUzBNVTdXbEtYMldJUXZUMDI0QlpQZDhPeUZBVEtV?= =?utf-8?B?Vnlaa05sMWs2UkVGaTVBM2NVR1JiMVQ0dmJaU0pJMlFZaGljUzh1OUlZOTNk?= =?utf-8?B?b2tpcVdUdnlmQ2VmQnpSOXMxRFpFclF1cVJ4ZFZGaU9DdURORGE3SktpYytG?= =?utf-8?B?SHBZM1M2ZExRV0lxL3NnSEhZRkFjdE1JT09TbHl2S2NLbjlvRSt3eGxJK3dX?= =?utf-8?B?cHplZ3VCRUQrNjByQU1FMnhXaGJxQnNpcDdDU1kwclcrRkxPekR4RXp1Y3BO?= =?utf-8?B?NE94STh3UXVHYzBFYWdVY29VY0pHaXpZQU0xeEs3eWU2WkpXQkZiaDdWSXhT?= =?utf-8?B?dm1wbk9MaXlsRzVnSWNybUlrSDVrejkxNmtydWR3ajEza1ZwblZRQmIvQjRU?= =?utf-8?B?MXV5QVk0T2Q2aUpOK2F4eVFHOTRDbjczMkV0S1phR05DNndSVTJjYWdlNWs4?= =?utf-8?B?M3BXT3FIbE1WL0JOTlZlVlB6NGZVZ0JQVFhlRktQc2hoMXV3UEZFdjhXUUlE?= =?utf-8?B?KzRNOEVSTnFwU1ZUOURtQzNPSWQxZkZNR0trRnBpRE9IN3czckYzS1hMTktl?= =?utf-8?B?Nk9nczhIY2IyRElFbXNWTUxIMURHY09FcFFuZWs3QTU2MnVxeTJzWHFTZ0hL?= =?utf-8?B?SkdJNS9OUkFGc09FVk1MZDdyUmRCY3FzZEJDcGlhU09uWTFDTUw1NWhZdzJ1?= =?utf-8?B?Um5yL2daaGRGUk9UUXV6cmlPdHRJd1c0YUo4N3NRKzVEa1ZqVVhWWTlGMk9X?= =?utf-8?Q?MERDsRrQQoQBl?= X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:IA1PR14MB6224.namprd14.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230040)(1800799024)(376014)(7416014)(52116014)(366016)(921020)(38350700014)(80162021);DIR:OUT;SFP:1102; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?dzlQZGVNME9vY2FOMWYrb0RJeVNFdnFXblhaRnFFMmlVY3k3clpNNUg5RUt0?= =?utf-8?B?eitCck9zdTRPay9mQkp2WkFVa256YkpxVUFNL2hJWm16dmlpN3N4QVY2MytY?= =?utf-8?B?MlNxRnNWWjBvc0RZa0Zwd0ZWY1JJK01mVEJtNXZha09yc3VZcHVQbkdBekJL?= =?utf-8?B?STdkSTJ3NkxXeGdQcmhXWkFkYVM2azlkVU4vYVNYK1grVGVEYSsreGpKcmZG?= =?utf-8?B?ZHVnQVJEbFdiOVpyUVdqWWhOVko4a0I5OXJuNWZIbjB3dDhoZjBhQkFhZjFx?= =?utf-8?B?ckFEbTdBZGJVNE55b0NyYjFxcVBEREd6MlFJRlRVdlRpMGhnSElRWUZYN05o?= =?utf-8?B?ZHpNTlJVY2IyblpCT0RkcTVBbUQ5Q0RjSG5GSm5iMGJJZklNNHhEZXlkMlZ0?= =?utf-8?B?dEh4YXhrSFdLOWNRYk5NTnhOYTg4dUp5Sk1OZHJpazZnT2RWdmZWN1dzbm5z?= =?utf-8?B?VnRPU3VSS3p6UmpnYWJOTGhqZGx0SW91RGJSVlhXYWxLbWplejJHMHQyS25p?= =?utf-8?B?T3g5b05OOS9wc1RNRHVLNDF6M1BjenNGbzlVaHFxY21EZk91OWVDcjY3cWFC?= =?utf-8?B?WUV4TDk1TEhSUlduY0UwOEJGZ1dqVkpaYUtqNkJ2bzN4M2dydUVzeUNHSW51?= =?utf-8?B?alExSUtjQk5PclQrb1hKdWJHSTZISURuM3dkRk50aUkxeTU3UVZmZUVuYnRT?= =?utf-8?B?QWQ4K2psWHZqSjhSUE9WZzFxeWtvS2dwVEY5SVNGRlVzc0N3Y05aN2NhMWto?= =?utf-8?B?OEhBanNPamt1NHRFb1N3emxMdjNBa0ZvWXRmMndLSzBhaU5Eb0RFSFNoNmwr?= =?utf-8?B?TW1TM2pYNmg4Sll1aWg5NHIvalhoclUxeUUzZDNla2V0TmhnbHQ5MjY1TUVV?= =?utf-8?B?OGhKYkNLYTlzVm94ZG9WelUxTG5Jek5Sc2E1SUNUUjNsaVQrNW85VWF2dExF?= =?utf-8?B?WUIzd2o1cldZU0ExNVFLcFQ0UjlicHNwdkk2ZFlXSEVCN3VHazVCTXJPZy9j?= =?utf-8?B?RitvVG9hQXBJUDNHd1VCcXhIOFc5SU5zK3BybXQ0ZitNd3BmVE1QQnh3L1Zr?= =?utf-8?B?K3U0T0ZrM254bUJLVnJ5OGo5akU4cGw0cm9rMGhkZm5Ud0tCU0Q0R2tYRUZJ?= =?utf-8?B?THJPTXNaRnNkOENVbHBLcitPVlJuMEtyNGVtZDN5TEFSWTB4cXp0WnJWRTFF?= =?utf-8?B?ditIMThVSHVXbG5ucUgzeUVUbGhSUXY1bEdhcG1JUkxEcmwvcGdGT3gxODJO?= =?utf-8?B?RVVIYXJsSXdRZkZXWndIUWFCQ3g5WENZTW01REhUN1I3TzVGcFFKdDdHblBi?= =?utf-8?B?d1ZpZEhzak9SM0svR3VWZmtrNFZDdE4ya3hxS1lYSkRLVWVSUEQzZ0J2Qy9B?= =?utf-8?B?Q3lNZlE2SkEvaUJnSm1Cd1BKR3hpd1pvNkppRGNKYkpCc3crMjJZWkJPMXhX?= =?utf-8?B?ZzB3eE1tbkMwd0c5ZWNPdnZtMkFOakpzbGp3K2dRTHIzU2Y1SWMxWjdBVjVt?= =?utf-8?B?a3Z2R1RZZzUwcUtoZHJubVNWZ0pIV05IWXRLMVVJa3J1M21vWk8wdEM4dVJR?= =?utf-8?B?SzFmYk9BUGJDN0JnWUNOK25wcmtFTTU2VG13bUFFaGFYZzF3eVMwRFgzMkc3?= =?utf-8?B?cWpEd0JRMXQ2bUQwMkh0cDRtRW5YeCtMc2dTZkduanVTUi9LaGllblBDUEVi?= =?utf-8?B?WUdmN2hKemhhTkwvREpzNVBmemwwMGZMU1d2R1orQzJoakYyYzlKSGJ5eWtG?= =?utf-8?B?SzZZbUNHZHFOY09iSE1KeUhGRUtBRFVsWU1GZVhvaFNyTG0rNThWb2I3WTNj?= =?utf-8?B?NnE3b0x5b3ZNc2dQOTBxRWg1SnhwSzVTVTdyOUQ4ekNtQVNiVmwwd1daRG0r?= =?utf-8?B?NXpjc092ZjZNZ2tNUVJNempaejlnZkNLdVZhSWFjK05kV1dkQ1QyT3ZkZnhC?= =?utf-8?B?M0laOFlYbXE1NVY3Y09vT2VEYWwvc3UvNjVhZjNYZUtKRUJCNjE2VndxUUxE?= =?utf-8?B?ZUJhOEdwZEhzV1hoaGFmUURGYkdWU0ZuNzV1NTJUc1NCOU5iTnpiUjAxWUto?= =?utf-8?B?cEhsRnE5KzgwL3p1aDY1K2RIRms2M1ZzYWJVOVp5SnBwU0RMdjh2d3FxRUp4?= =?utf-8?Q?IewiSUorJIzssw6rXf/BUV4vx?= X-OriginatorOrg: kneron.us X-MS-Exchange-CrossTenant-Network-Message-Id: 951e3701-48dd-4909-8dd6-08dcdeb4d14a X-MS-Exchange-CrossTenant-AuthSource: IA1PR14MB6224.namprd14.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 27 Sep 2024 05:25:36.9013 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: f92b0f4b-650a-4d8a-bae3-0e64697d65f2 X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: 1x2wL9b1blRbXTXQEBB5V56GP1F6LFOw3pvxUOyWNL4LNLCK29Tc2cQMXppwhko1wop5BryQbGKs6FheUdEqng== X-MS-Exchange-Transport-CrossTenantHeadersStamped: DM6PR14MB3449 In commit 35eba185fd1a ("i2c: designware: Calculate SCL timing parameter for High Speed Mode") hs_hcnt and hs_lcnt are calculated based on fixed tHIGH =3D 160 and tLOW =3D 120. However, the set of these fixed values only applies to the combination of hardware parameters IC_CAP_LOADING =3D 400pF and IC_CLK_FREQ_OPTIMIZATION =3D 1. Outside of this combination, if these fixed tHIGH =3D 160 and tLOW =3D 120 are still used, the calculated hs_hcnt and hs_lcnt may not be small enough, making it impossible for the SCL frequency to reach 3.4 MHz. Section 3.15.4.5 in DesignWare DW_apb_i2b Databook v2.03 says that when IC_CLK_FREQ_OPTIMIZATION =3D 0, MIN_SCL_HIGHtime =3D 60 ns for 3.4 Mbps, bus loading =3D 100pF =3D 120 ns for 3.4 Mbps, bus loading =3D 400pF MIN_SCL_LOWtime =3D 160 ns for 3.4 Mbps, bus loading =3D 100pF =3D 320 ns for 3.4 Mbps, bus loading =3D 400pF and section 3.15.4.6 says that when IC_CLK_FREQ_OPTIMIZATION =3D 1, MIN_SCL_HIGHtime =3D 60 ns for 3.4 Mbps, bus loading =3D 100pF =3D 160 ns for 3.4 Mbps, bus loading =3D 400pF MIN_SCL_LOWtime =3D 120 ns for 3.4 Mbps, bus loading =3D 100pF =3D 320 ns for 3.4 Mbps, bus loading =3D 400pF In order to calculate more accurate hs_hcnt amd hs_lcnt, two hardware parameters IC_CAP_LOADING and IC_CLK_FREQ_OPTIMIZATION must be considered together. Signed-off-by: Michael Wu --- drivers/i2c/busses/i2c-designware-common.c | 16 ++++++++++++++++ drivers/i2c/busses/i2c-designware-core.h | 6 ++++++ drivers/i2c/busses/i2c-designware-master.c | 14 ++++++++++++-- 3 files changed, 34 insertions(+), 2 deletions(-) diff --git a/drivers/i2c/busses/i2c-designware-common.c b/drivers/i2c/busse= s/i2c-designware-common.c index 080204182bb5..907f049f09f8 100644 --- a/drivers/i2c/busses/i2c-designware-common.c +++ b/drivers/i2c/busses/i2c-designware-common.c @@ -372,6 +372,20 @@ static void i2c_dw_adjust_bus_speed(struct dw_i2c_dev = *dev) t->bus_freq_hz =3D I2C_MAX_FAST_MODE_FREQ; } =20 +static void i2c_dw_fw_parse_hw_params(struct dw_i2c_dev *dev) +{ + struct device *device =3D dev->dev; + int ret; + + ret =3D device_property_read_u32(device, "bus-capacitance-pf", &dev->bus_= capacitance_pf); + if (ret || dev->bus_capacitance_pf < 400) + dev->bus_capacitance_pf =3D 100; + else + dev->bus_capacitance_pf =3D 400; + + dev->clk_freq_optimized =3D device_property_read_bool(device, "clk-freq-o= ptimized"); +} + int i2c_dw_fw_parse_and_configure(struct dw_i2c_dev *dev) { struct i2c_timings *t =3D &dev->timings; @@ -380,6 +394,8 @@ int i2c_dw_fw_parse_and_configure(struct dw_i2c_dev *de= v) =20 i2c_parse_fw_timings(device, t, false); =20 + i2c_dw_fw_parse_hw_params(dev); + i2c_dw_adjust_bus_speed(dev); =20 if (is_of_node(fwnode)) diff --git a/drivers/i2c/busses/i2c-designware-core.h b/drivers/i2c/busses/= i2c-designware-core.h index 1ac2afd03a0a..893c2c53648a 100644 --- a/drivers/i2c/busses/i2c-designware-core.h +++ b/drivers/i2c/busses/i2c-designware-core.h @@ -240,6 +240,10 @@ struct reset_control; * @set_sda_hold_time: callback to retrieve IP specific SDA hold timing * @mode: operation mode - DW_IC_MASTER or DW_IC_SLAVE * @rinfo: I=C2=B2C GPIO recovery information + * @bus_capacitance_pf: bus capacitance in picofarad + * @clk_freq_optimized: indicate whether the hardware input clock frequenc= y is + * reduced by reducing the internal latency required to generate the high + * period and low period of the SCL line * * HCNT and LCNT parameters can be used if the platform knows more accurate * values than the one computed based only on the input clock frequency. @@ -297,6 +301,8 @@ struct dw_i2c_dev { int (*set_sda_hold_time)(struct dw_i2c_dev *dev); int mode; struct i2c_bus_recovery_info rinfo; + u32 bus_capacitance_pf; + bool clk_freq_optimized; }; =20 #define ACCESS_INTR_MASK BIT(0) diff --git a/drivers/i2c/busses/i2c-designware-master.c b/drivers/i2c/busse= s/i2c-designware-master.c index e46f1b22c360..b18da66da6a8 100644 --- a/drivers/i2c/busses/i2c-designware-master.c +++ b/drivers/i2c/busses/i2c-designware-master.c @@ -154,12 +154,22 @@ static int i2c_dw_set_timings_master(struct dw_i2c_de= v *dev) dev->hs_hcnt =3D 0; dev->hs_lcnt =3D 0; } else if (!dev->hs_hcnt || !dev->hs_lcnt) { + u32 t_high, t_low; + + if (dev->bus_capacitance_pf =3D=3D 400) { + t_high =3D dev->clk_freq_optimized ? 160 : 120; + t_low =3D 320; + } else { + t_high =3D 60; + t_low =3D dev->clk_freq_optimized ? 120 : 160; + } + ic_clk =3D i2c_dw_clk_rate(dev); dev->hs_hcnt =3D i2c_dw_scl_hcnt(dev, DW_IC_HS_SCL_HCNT, ic_clk, - 160, /* tHIGH =3D 160 ns */ + t_high, sda_falling_time, 0, /* DW default */ 0); /* No offset */ @@ -167,7 +177,7 @@ static int i2c_dw_set_timings_master(struct dw_i2c_dev = *dev) i2c_dw_scl_lcnt(dev, DW_IC_HS_SCL_LCNT, ic_clk, - 320, /* tLOW =3D 320 ns */ + t_low, scl_falling_time, 0); /* No offset */ } --=20 2.43.0