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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	[thread overview]
Message-ID: <20201120093058.7248-2-zhiyong.tao@mediatek.com> (raw)
In-Reply-To: <20201120093058.7248-1-zhiyong.tao@mediatek.com>

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


  reply	other threads:[~2020-11-20  9:31 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-11-20  9:30 [PATCH 0/1] Mediatek pinctrl patch Zhiyong Tao
2020-11-20  9:30 ` Zhiyong Tao [this message]
2020-12-04  8:43   ` [PATCH] pinctrl: fix low level output voltage issue Linus Walleij

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