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Tue, 02 Mar 2021 03:30:32 -0800 (PST) MIME-Version: 1.0 References: <1612348525-13364-1-git-send-email-qii.wang@mediatek.com> In-Reply-To: <1612348525-13364-1-git-send-email-qii.wang@mediatek.com> From: Ikjoon Jang Date: Tue, 2 Mar 2021 19:30:21 +0800 Message-ID: Subject: Re: [PATCH] i2c: mediatek: Get device clock-stretch time via dts To: qii.wang@mediatek.com Cc: wsa@the-dreams.de, srv_heupstream , leilk.liu@mediatek.com, open list , "moderated list:ARM/Mediatek SoC support" , linux-i2c@vger.kernel.org, Matthias Brugger , "moderated list:ARM/Mediatek SoC support" Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Qii, On Wed, Feb 3, 2021 at 6:43 PM wrote: > > From: Qii Wang > > tSU,STA/tHD,STA/tSU,STOP maybe out of spec due to device > clock-stretching or circuit loss, we could get device > clock-stretch time from dts to adjust these parameters > to meet the spec via EXT_CONF register. > > Signed-off-by: Qii Wang > --- > drivers/i2c/busses/i2c-mt65xx.c | 6 +++++- > 1 file changed, 5 insertions(+), 1 deletion(-) > > diff --git a/drivers/i2c/busses/i2c-mt65xx.c b/drivers/i2c/busses/i2c-mt65xx.c > index 2ffd2f3..47c7255 100644 > --- a/drivers/i2c/busses/i2c-mt65xx.c > +++ b/drivers/i2c/busses/i2c-mt65xx.c > @@ -245,6 +245,7 @@ struct mtk_i2c { > u16 irq_stat; /* interrupt status */ > unsigned int clk_src_div; > unsigned int speed_hz; /* The speed in transfer */ > + unsigned int clock_stretch_ns; > enum mtk_trans_op op; > u16 timing_reg; > u16 high_speed_reg; > @@ -607,7 +608,8 @@ static int mtk_i2c_check_ac_timing(struct mtk_i2c *i2c, > else > clk_ns = sample_ns / 2; > > - su_sta_cnt = DIV_ROUND_UP(spec->min_su_sta_ns, clk_ns); > + su_sta_cnt = DIV_ROUND_UP(spec->min_su_sta_ns + i2c->clock_stretch_ns, > + clk_ns); > if (su_sta_cnt > max_sta_cnt) > return -1; > > @@ -1171,6 +1173,8 @@ static int mtk_i2c_parse_dt(struct device_node *np, struct mtk_i2c *i2c) > if (i2c->clk_src_div == 0) > return -EINVAL; > > + of_property_read_u32(np, "clock-stretch-ns", &i2c->clock_stretch_ns); > + I think this new property "clock-stretch-ns" is for the same purpose of "i2c-scl-falling-time-ns" + "i2c-scl-rising-time-ns" defined in Documentation/devicetree/bindings/i2c/i2c.txt? > i2c->have_pmic = of_property_read_bool(np, "mediatek,have-pmic"); > i2c->use_push_pull = > of_property_read_bool(np, "mediatek,use-push-pull"); > -- > 1.9.1 > _______________________________________________ > Linux-mediatek mailing list > Linux-mediatek@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-mediatek 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=-13.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=unavailable 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 7466FC433E0 for ; Wed, 3 Mar 2021 17:19:34 +0000 (UTC) Received: from desiato.infradead.org (desiato.infradead.org [90.155.92.199]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id B016B64EDF for ; 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Tue, 02 Mar 2021 03:30:32 -0800 (PST) MIME-Version: 1.0 References: <1612348525-13364-1-git-send-email-qii.wang@mediatek.com> In-Reply-To: <1612348525-13364-1-git-send-email-qii.wang@mediatek.com> From: Ikjoon Jang Date: Tue, 2 Mar 2021 19:30:21 +0800 Message-ID: Subject: Re: [PATCH] i2c: mediatek: Get device clock-stretch time via dts To: qii.wang@mediatek.com Cc: wsa@the-dreams.de, srv_heupstream , leilk.liu@mediatek.com, open list , "moderated list:ARM/Mediatek SoC support" , linux-i2c@vger.kernel.org, Matthias Brugger , "moderated list:ARM/Mediatek SoC support" X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210302_113137_565889_A398DE36 X-CRM114-Status: GOOD ( 18.40 ) X-BeenThere: linux-mediatek@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "Linux-mediatek" Errors-To: linux-mediatek-bounces+linux-mediatek=archiver.kernel.org@lists.infradead.org Hi Qii, On Wed, Feb 3, 2021 at 6:43 PM wrote: > > From: Qii Wang > > tSU,STA/tHD,STA/tSU,STOP maybe out of spec due to device > clock-stretching or circuit loss, we could get device > clock-stretch time from dts to adjust these parameters > to meet the spec via EXT_CONF register. > > Signed-off-by: Qii Wang > --- > drivers/i2c/busses/i2c-mt65xx.c | 6 +++++- > 1 file changed, 5 insertions(+), 1 deletion(-) > > diff --git a/drivers/i2c/busses/i2c-mt65xx.c b/drivers/i2c/busses/i2c-mt65xx.c > index 2ffd2f3..47c7255 100644 > --- a/drivers/i2c/busses/i2c-mt65xx.c > +++ b/drivers/i2c/busses/i2c-mt65xx.c > @@ -245,6 +245,7 @@ struct mtk_i2c { > u16 irq_stat; /* interrupt status */ > unsigned int clk_src_div; > unsigned int speed_hz; /* The speed in transfer */ > + unsigned int clock_stretch_ns; > enum mtk_trans_op op; > u16 timing_reg; > u16 high_speed_reg; > @@ -607,7 +608,8 @@ static int mtk_i2c_check_ac_timing(struct mtk_i2c *i2c, > else > clk_ns = sample_ns / 2; > > - su_sta_cnt = DIV_ROUND_UP(spec->min_su_sta_ns, clk_ns); > + su_sta_cnt = DIV_ROUND_UP(spec->min_su_sta_ns + i2c->clock_stretch_ns, > + clk_ns); > if (su_sta_cnt > max_sta_cnt) > return -1; > > @@ -1171,6 +1173,8 @@ static int mtk_i2c_parse_dt(struct device_node *np, struct mtk_i2c *i2c) > if (i2c->clk_src_div == 0) > return -EINVAL; > > + of_property_read_u32(np, "clock-stretch-ns", &i2c->clock_stretch_ns); > + I think this new property "clock-stretch-ns" is for the same purpose of "i2c-scl-falling-time-ns" + "i2c-scl-rising-time-ns" defined in Documentation/devicetree/bindings/i2c/i2c.txt? > i2c->have_pmic = of_property_read_bool(np, "mediatek,have-pmic"); > i2c->use_push_pull = > of_property_read_bool(np, "mediatek,use-push-pull"); > -- > 1.9.1 > _______________________________________________ > Linux-mediatek mailing list > Linux-mediatek@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-mediatek _______________________________________________ Linux-mediatek mailing list Linux-mediatek@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-mediatek 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=-13.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=unavailable 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 52376C433DB for ; Wed, 3 Mar 2021 16:01:09 +0000 (UTC) Received: from desiato.infradead.org (desiato.infradead.org [90.155.92.199]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 7793A64DF2 for ; 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Tue, 02 Mar 2021 03:30:32 -0800 (PST) MIME-Version: 1.0 References: <1612348525-13364-1-git-send-email-qii.wang@mediatek.com> In-Reply-To: <1612348525-13364-1-git-send-email-qii.wang@mediatek.com> From: Ikjoon Jang Date: Tue, 2 Mar 2021 19:30:21 +0800 Message-ID: Subject: Re: [PATCH] i2c: mediatek: Get device clock-stretch time via dts To: qii.wang@mediatek.com Cc: wsa@the-dreams.de, srv_heupstream , leilk.liu@mediatek.com, open list , "moderated list:ARM/Mediatek SoC support" , linux-i2c@vger.kernel.org, Matthias Brugger , "moderated list:ARM/Mediatek SoC support" X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210302_113138_981438_CDBAC591 X-CRM114-Status: GOOD ( 20.15 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Hi Qii, On Wed, Feb 3, 2021 at 6:43 PM wrote: > > From: Qii Wang > > tSU,STA/tHD,STA/tSU,STOP maybe out of spec due to device > clock-stretching or circuit loss, we could get device > clock-stretch time from dts to adjust these parameters > to meet the spec via EXT_CONF register. > > Signed-off-by: Qii Wang > --- > drivers/i2c/busses/i2c-mt65xx.c | 6 +++++- > 1 file changed, 5 insertions(+), 1 deletion(-) > > diff --git a/drivers/i2c/busses/i2c-mt65xx.c b/drivers/i2c/busses/i2c-mt65xx.c > index 2ffd2f3..47c7255 100644 > --- a/drivers/i2c/busses/i2c-mt65xx.c > +++ b/drivers/i2c/busses/i2c-mt65xx.c > @@ -245,6 +245,7 @@ struct mtk_i2c { > u16 irq_stat; /* interrupt status */ > unsigned int clk_src_div; > unsigned int speed_hz; /* The speed in transfer */ > + unsigned int clock_stretch_ns; > enum mtk_trans_op op; > u16 timing_reg; > u16 high_speed_reg; > @@ -607,7 +608,8 @@ static int mtk_i2c_check_ac_timing(struct mtk_i2c *i2c, > else > clk_ns = sample_ns / 2; > > - su_sta_cnt = DIV_ROUND_UP(spec->min_su_sta_ns, clk_ns); > + su_sta_cnt = DIV_ROUND_UP(spec->min_su_sta_ns + i2c->clock_stretch_ns, > + clk_ns); > if (su_sta_cnt > max_sta_cnt) > return -1; > > @@ -1171,6 +1173,8 @@ static int mtk_i2c_parse_dt(struct device_node *np, struct mtk_i2c *i2c) > if (i2c->clk_src_div == 0) > return -EINVAL; > > + of_property_read_u32(np, "clock-stretch-ns", &i2c->clock_stretch_ns); > + I think this new property "clock-stretch-ns" is for the same purpose of "i2c-scl-falling-time-ns" + "i2c-scl-rising-time-ns" defined in Documentation/devicetree/bindings/i2c/i2c.txt? > i2c->have_pmic = of_property_read_bool(np, "mediatek,have-pmic"); > i2c->use_push_pull = > of_property_read_bool(np, "mediatek,use-push-pull"); > -- > 1.9.1 > _______________________________________________ > Linux-mediatek mailing list > Linux-mediatek@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-mediatek _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel