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From:   Zhiyong Tao <zhiyong.tao@mediatek.com>
To:     <robh+dt@kernel.org>, <linus.walleij@linaro.org>,
        <mark.rutland@arm.com>, <matthias.bgg@gmail.com>,
        <sean.wang@kernel.org>
CC:     <srv_heupstream@mediatek.com>, <zhiyong.tao@mediatek.com>,
        <hui.liu@mediatek.com>, <eddie.huang@mediatek.com>,
        <jg_poxu@mediatek.com>, <biao.huang@mediatek.com>,
        <hongzhou.yang@mediatek.com>, <erin.lo@mediatek.com>,
        <sean.wang@mediatek.com>, <seiya.wang@mediatek.com>,
        <sj.huang@mediatek.com>, <devicetree@vger.kernel.org>,
        <linux-kernel@vger.kernel.org>,
        <linux-arm-kernel@lists.infradead.org>,
        <linux-mediatek@lists.infradead.org>, <linux-gpio@vger.kernel.org>
Subject: [PATCH] pinctrl: fix low level output voltage issue
Date:   Fri, 20 Nov 2020 17:30:58 +0800
Message-ID: <20201120093058.7248-2-zhiyong.tao@mediatek.com>
In-Reply-To: <20201120093058.7248-1-zhiyong.tao@mediatek.com>
References: <20201120093058.7248-1-zhiyong.tao@mediatek.com>
MIME-Version: 1.0
Content-Type: text/plain
Precedence: bulk

This patch is used to fix low level output voltage issue.
A pin is changed from input pull-up to output high.
The Dout value of the pin is default as 0.
If we change the direction of the pin before the dout value of the pin,
It maybe produce a low level output voltage between "input pull-up" and
"output high".

Signed-off-by: Zhiyong Tao <zhiyong.tao@mediatek.com>
---
 drivers/pinctrl/mediatek/pinctrl-paris.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/pinctrl/mediatek/pinctrl-paris.c b/drivers/pinctrl/mediatek/pinctrl-paris.c
index 623af4410b07..039ce9be19c5 100644
--- a/drivers/pinctrl/mediatek/pinctrl-paris.c
+++ b/drivers/pinctrl/mediatek/pinctrl-paris.c
@@ -247,13 +247,13 @@ static int mtk_pinconf_set(struct pinctrl_dev *pctldev, unsigned int pin,
 		err = mtk_hw_set_value(hw, desc, PINCTRL_PIN_REG_SR, !!arg);
 		break;
 	case PIN_CONFIG_OUTPUT:
-		err = mtk_hw_set_value(hw, desc, PINCTRL_PIN_REG_DIR,
-				       MTK_OUTPUT);
+		err = mtk_hw_set_value(hw, desc, PINCTRL_PIN_REG_DO,
+				       arg);
 		if (err)
 			goto err;
 
-		err = mtk_hw_set_value(hw, desc, PINCTRL_PIN_REG_DO,
-				       arg);
+		err = mtk_hw_set_value(hw, desc, PINCTRL_PIN_REG_DIR,
+				       MTK_OUTPUT);
 		break;
 	case PIN_CONFIG_INPUT_SCHMITT:
 	case PIN_CONFIG_INPUT_SCHMITT_ENABLE:
-- 
2.18.0