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=-7.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,UNPARSEABLE_RELAY 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 1D9E3C43381 for ; Thu, 7 Mar 2019 04:58:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id EA1C620835 for ; Thu, 7 Mar 2019 04:58:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726607AbfCGE6I (ORCPT ); Wed, 6 Mar 2019 23:58:08 -0500 Received: from mailgw02.mediatek.com ([1.203.163.81]:8522 "EHLO mailgw02.mediatek.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1726127AbfCGE6I (ORCPT ); Wed, 6 Mar 2019 23:58:08 -0500 X-UUID: 53ec318dcbf743ab9b199bfe5cd5c022-20190307 X-UUID: 53ec318dcbf743ab9b199bfe5cd5c022-20190307 Received: from mtkcas36.mediatek.inc [(172.27.4.253)] by mailgw02.mediatek.com (envelope-from ) (mailgw01.mediatek.com ESMTP with TLS) with ESMTP id 828892857; Thu, 07 Mar 2019 12:57:59 +0800 Received: from MTKCAS32.mediatek.inc (172.27.4.184) by MTKMBS31N2.mediatek.inc (172.27.4.87) with Microsoft SMTP Server (TLS) id 15.0.1395.4; Thu, 7 Mar 2019 12:57:58 +0800 Received: from [10.17.3.153] (172.27.4.253) by MTKCAS32.mediatek.inc (172.27.4.170) with Microsoft SMTP Server id 15.0.1395.4 via Frontend Transport; Thu, 7 Mar 2019 12:57:57 +0800 Message-ID: <1551934677.30363.55.camel@mhfsdcap03> Subject: Re: [PATCH v5 3/5] i2c: mediatek: Add arb clock in i2c driver From: Qii Wang To: Nicolas Boichat CC: , , , linux-arm Mailing List , lkml , "moderated list:ARM/Mediatek SoC support" , srv_heupstream , Leilk Liu , , , Rob Herring Date: Thu, 7 Mar 2019 12:57:57 +0800 In-Reply-To: References: <1551186660-16902-1-git-send-email-qii.wang@mediatek.com> <1551186660-16902-4-git-send-email-qii.wang@mediatek.com> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.2.3-0ubuntu6 Content-Transfer-Encoding: 7bit MIME-Version: 1.0 X-MTK: N Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 2019-03-06 at 18:49 +0800, Nicolas Boichat wrote: > One thing I missed from Matthias' comment on v4: > https://patchwork.kernel.org/patch/10822083/ > > On Wed, Mar 6, 2019 at 6:44 PM Nicolas Boichat wrote: > > > > On Tue, Feb 26, 2019 at 9:11 PM Qii Wang wrote: > > > > > > When two i2c controllers are internally connected to the same > > > GPIO pins, the arb clock is needed to ensure that the waveforms > > > do not interfere with each other. > > > > > > Signed-off-by: Qii Wang > > > > Reviewed-by: Nicolas Boichat > > > > > --- > > > drivers/i2c/busses/i2c-mt65xx.c | 25 ++++++++++++++++++++++--- > > > 1 file changed, 22 insertions(+), 3 deletions(-) > > > > > > diff --git a/drivers/i2c/busses/i2c-mt65xx.c b/drivers/i2c/busses/i2c-mt65xx.c > > > index 428ac99..14d6b38 100644 > > > --- a/drivers/i2c/busses/i2c-mt65xx.c > > > +++ b/drivers/i2c/busses/i2c-mt65xx.c > > > @@ -35,6 +35,7 @@ > > > #include > > > > > > #define I2C_RS_TRANSFER (1 << 4) > > > +#define I2C_ARB_LOST (1 << 3) > > > #define I2C_HS_NACKERR (1 << 2) > > > #define I2C_ACKERR (1 << 1) > > > #define I2C_TRANSAC_COMP (1 << 0) > > > @@ -181,6 +182,7 @@ struct mtk_i2c { > > > struct clk *clk_main; /* main clock for i2c bus */ > > > struct clk *clk_dma; /* DMA clock for i2c via DMA */ > > > struct clk *clk_pmic; /* PMIC clock for i2c from PMIC */ > > > + struct clk *clk_arb; /* Arbitrator clock for i2c */ > > > bool have_pmic; /* can use i2c pins from PMIC */ > > > bool use_push_pull; /* IO config push-pull mode */ > > > > > > @@ -299,8 +301,18 @@ static int mtk_i2c_clock_enable(struct mtk_i2c *i2c) > > > if (ret) > > > goto err_pmic; > > > } > > > + > > > + if (i2c->clk_arb) { > > > + ret = clk_prepare_enable(i2c->clk_arb); > > > + if (ret) > > > + goto err_arb; > > > + } > > > + > > > return 0; > > > > > > +err_arb: > > > + if (i2c->have_pmic) > > > + clk_disable_unprepare(i2c->clk_pmic); > > > err_pmic: > > > clk_disable_unprepare(i2c->clk_main); > > > err_main: > > > @@ -311,6 +323,9 @@ static int mtk_i2c_clock_enable(struct mtk_i2c *i2c) > > > > > > static void mtk_i2c_clock_disable(struct mtk_i2c *i2c) > > > { > > > + if (i2c->clk_arb) > > > + clk_disable_unprepare(i2c->clk_arb); > > > + > > > if (i2c->have_pmic) > > > clk_disable_unprepare(i2c->clk_pmic); > > > > > > @@ -519,13 +534,13 @@ static int mtk_i2c_do_transfer(struct mtk_i2c *i2c, struct i2c_msg *msgs, > > > > > > /* Clear interrupt status */ > > > mtk_i2c_writew(i2c, restart_flag | I2C_HS_NACKERR | I2C_ACKERR | > > > - I2C_TRANSAC_COMP, OFFSET_INTR_STAT); > > > + I2C_ARB_LOST | I2C_TRANSAC_COMP, OFFSET_INTR_STAT); > > Is it ok to set I2C_ARB_LOST on _all_ SoC that this driver supports? > If so, please at least say so in the commit message. > Yes, old and new SoC have the I2C_ARB_LOST bit, but there was no need for multi-master before, so we didn't set it up specifically, I have test the patch on the old SoCs. I will add a note in the commit message. > > > > > > mtk_i2c_writew(i2c, I2C_FIFO_ADDR_CLR, OFFSET_FIFO_ADDR_CLR); > > > > > > /* Enable interrupt */ > > > mtk_i2c_writew(i2c, restart_flag | I2C_HS_NACKERR | I2C_ACKERR | > > > - I2C_TRANSAC_COMP, OFFSET_INTR_MASK); > > > + I2C_ARB_LOST | I2C_TRANSAC_COMP, OFFSET_INTR_MASK); > > > > > > /* Set transfer and transaction len */ > > > if (i2c->op == I2C_MASTER_WRRD) { > > > @@ -659,7 +674,7 @@ static int mtk_i2c_do_transfer(struct mtk_i2c *i2c, struct i2c_msg *msgs, > > > > > > /* Clear interrupt mask */ > > > mtk_i2c_writew(i2c, ~(restart_flag | I2C_HS_NACKERR | I2C_ACKERR | > > > - I2C_TRANSAC_COMP), OFFSET_INTR_MASK); > > > + I2C_ARB_LOST | I2C_TRANSAC_COMP), OFFSET_INTR_MASK); > > > > > > if (i2c->op == I2C_MASTER_WR) { > > > dma_unmap_single(i2c->dev, wpaddr, > > > @@ -884,6 +899,10 @@ static int mtk_i2c_probe(struct platform_device *pdev) > > > return PTR_ERR(i2c->clk_dma); > > > } > > > > > > + i2c->clk_arb = devm_clk_get(&pdev->dev, "arb"); > > > + if (IS_ERR(i2c->clk_arb)) > > > + i2c->clk_arb = NULL; > > > + > > > clk = i2c->clk_main; > > > if (i2c->have_pmic) { > > > i2c->clk_pmic = devm_clk_get(&pdev->dev, "pmic"); > > > -- > > > 1.7.9.5 > > >