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 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C24F0C433FE for ; Tue, 5 Oct 2021 00:32:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AA0FA61357 for ; Tue, 5 Oct 2021 00:32:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229689AbhJEAeT (ORCPT ); Mon, 4 Oct 2021 20:34:19 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49294 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229549AbhJEAeS (ORCPT ); Mon, 4 Oct 2021 20:34:18 -0400 Received: from mail-oo1-xc31.google.com (mail-oo1-xc31.google.com [IPv6:2607:f8b0:4864:20::c31]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id F020AC061749; Mon, 4 Oct 2021 17:32:28 -0700 (PDT) Received: by mail-oo1-xc31.google.com with SMTP id h11-20020a4aa74b000000b002a933d156cbso5943253oom.4; Mon, 04 Oct 2021 17:32:28 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=sender:from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=M1qcgIHaPDeZOBFimBfle5VA+3VdIMSsVgxkS7mTJT4=; b=Ksno/c28MANOAWq2olo4ceUolsouIJXch/i3XT0FPmxuXAOaAOxVcWqpR/hMnCcde0 fkC8XtI2GROo+nMfYe5M97ILHqD83Linr9vVpIAIWqHCSOFx9b6DBxuH19cKnkB6PB4x vn0srxdcf+TOt7ljHdz1q41a7H3hmoXufTuqj8ofov52u6R00dMuyasu2Ev5zJc4TfbM 34NY/f5ffAek/tzh4d7GQs7nAHUSR4hmjC52eJCpEMqowGGLrVglJjDyKNxGLOUv33dc iwLJTChko1WU1wqZ3UuKTXY7LqLI89/iTleiOTbUiITKXSjcyMUKoYgkAGc+a7xRwS63 c0hg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:sender:from:to:cc:subject:date:message-id :in-reply-to:references:mime-version:content-transfer-encoding; bh=M1qcgIHaPDeZOBFimBfle5VA+3VdIMSsVgxkS7mTJT4=; b=dnQMJZ5YV9G4D49AxBqlxwwi7pKPhSACIFMC0Bmd5uZftDqXyR4Lh+5ZeKH/ha9rkZ Xk2tFcAuCKXNesRM+70ORmM61ABIYq/XAKQZ7W19K0YJTj9K3qaHn6D6Ljx9QhQas0Qn b+8d8k9mmCZfn0fOiRk7bv955PZ1qV7nEBjQvBsmh9u5QfAHDJbn4tKY6R6OO618ir0l G1eG5XOkYXtEKbgjgIwlHIPg/WAPcfMlZCOx5ziCKeVHcrXmnjsznUWtBELWroPytr0W rMyGqIJ+sIFkwnacUXoRlmED9ZuAUKAd74v+kHPggXf1ib7VPh4AG/aaTXE809VHkAUo 8WWw== X-Gm-Message-State: AOAM533/a15KLmzCbDoqglVoPaYQXrP352ImJL+FNVyVu3bm6+Q4ZIYY NroePCmPN4xr3HVSLcMVRg== X-Google-Smtp-Source: ABdhPJwUo5LF/Ewws7Lph7371x+WJMB9viQ1nsgYkhKjddV5NB77w+xq69hGLhIcCQ4yz90fZzqd4g== X-Received: by 2002:a4a:424b:: with SMTP id i11mr11212055ooj.87.1633393948213; Mon, 04 Oct 2021 17:32:28 -0700 (PDT) Received: from serve.minyard.net (serve.minyard.net. [2001:470:b8f6:1b::1]) by smtp.gmail.com with ESMTPSA id h23sm1119340otl.54.2021.10.04.17.32.27 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 04 Oct 2021 17:32:27 -0700 (PDT) Sender: Corey Minyard Received: from t560.minyard.net (unknown [IPv6:2001:470:b8f6:1b:1ce5:3fb4:8fe9:30d1]) by serve.minyard.net (Postfix) with ESMTPA id CB9F71800F6; Tue, 5 Oct 2021 00:32:26 +0000 (UTC) From: minyard@acm.org To: Oleksij Rempel Cc: Pengutronix Kernel Team , linux-i2c@vger.kernel.org, Andrew Manley , linux-kernel@vger.kernel.org, Corey Minyard , Corey Minyard Subject: [PATCH 2/3] i2c:imx: Add an extra read at the end of an I2C slave read Date: Mon, 4 Oct 2021 19:32:15 -0500 Message-Id: <20211005003216.2670632-3-minyard@acm.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20211005003216.2670632-1-minyard@acm.org> References: <20211005003216.2670632-1-minyard@acm.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-i2c@vger.kernel.org From: Corey Minyard The I2C slave interface expects that the driver will read ahead one byte. The IMX driver/device doesn't do this, but simulate it so that read operations get their index set correctly. Signed-off-by: Corey Minyard Tested-by: Andrew Manley Reviewed-by: Andrew Manley --- drivers/i2c/busses/i2c-imx.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/drivers/i2c/busses/i2c-imx.c b/drivers/i2c/busses/i2c-imx.c index 97369fe48b30..26a04dc0590b 100644 --- a/drivers/i2c/busses/i2c-imx.c +++ b/drivers/i2c/busses/i2c-imx.c @@ -769,6 +769,15 @@ static irqreturn_t i2c_imx_slave_handle(struct imx_i2c_struct *i2c_imx, ctl &= ~I2CR_MTX; imx_i2c_write_reg(ctl, i2c_imx, IMX_I2C_I2CR); imx_i2c_read_reg(i2c_imx, IMX_I2C_I2DR); + + /* + * The i2c slave interface requires one extra dummy + * read at the end to keep things in line. See the + * I2C slave docs for details. + */ + i2c_imx_slave_event(i2c_imx, + I2C_SLAVE_READ_PROCESSED, &value); + i2c_imx_slave_finish_op(i2c_imx); return IRQ_HANDLED; } -- 2.25.1