From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5F0B5C28CF6 for ; Wed, 1 Aug 2018 13:35:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 20BD9208A4 for ; Wed, 1 Aug 2018 13:35:35 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 20BD9208A4 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=microchip.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389421AbeHAPVV (ORCPT ); Wed, 1 Aug 2018 11:21:21 -0400 Received: from esa5.microchip.iphmx.com ([216.71.150.166]:59737 "EHLO esa5.microchip.iphmx.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389338AbeHAPVV (ORCPT ); Wed, 1 Aug 2018 11:21:21 -0400 X-IronPort-AV: E=Sophos;i="5.51,432,1526367600"; d="scan'208";a="15042262" Received: from smtpout.microchip.com (HELO email.microchip.com) ([198.175.253.82]) by esa5.microchip.iphmx.com with ESMTP/TLS/DHE-RSA-AES256-SHA; 01 Aug 2018 06:35:32 -0700 Received: from localhost.localdomain.com (10.10.76.4) by chn-sv-exch02.mchp-main.com (10.10.76.38) with Microsoft SMTP Server id 14.3.352.0; Wed, 1 Aug 2018 06:35:31 -0700 From: Tudor Ambarus To: , , , , CC: , , , Tudor Ambarus Subject: [PATCH 0/2] i2c: enable buses to save their clock frequency in adapter Date: Wed, 1 Aug 2018 16:35:10 +0300 Message-ID: <20180801133512.12276-1-tudor.ambarus@microchip.com> X-Mailer: git-send-email 2.9.4 MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The clock-frequency property is not mandatory for the i2c buses. If it's not present in the device tree, the buses __usually__ assume it's 100kHZ (see altera, at91, axxia, etc.). Broadcom uses a 375kHZ default clock-frequency, so the default clock frequency varies from bus to bus. There are i2c clients that need to know the bus clock frequency in order to compute their wake token (see atecc508a i2c client). The clock-frequency value has to be propagated to the i2c clients, otherwise, if they will not find the i2c bus clock frequency in the device tree, they will have to make their own assumption of the clock frequency. Spare the i2c clients of making wrong assumptions of the i2c bus clock frequency and enable the buses to save their clock frequency in adapter. since rfc: - reword commit messages Tudor Ambarus (2): i2c: enable buses to save their clock frequency in adapter i2c: at91: Save the bus clock frequency in adapter drivers/i2c/busses/i2c-at91.c | 1 + include/linux/i2c.h | 1 + 2 files changed, 2 insertions(+) -- 2.9.4