linux-kernel - [PATCH v7 4/4] drm/mediatek: set dpi pin mode to gpio low to avoid leakage current

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Message-ID: <20200225064638.112282-5-jitao.shi@mediatek.com>
Date:   Tue, 25 Feb 2020 14:46:38 +0800
From:   Jitao Shi <jitao.shi@...iatek.com>
To:     Rob Herring <robh+dt@...nel.org>,
        Mark Rutland <mark.rutland@....com>,
        Matthias Brugger <matthias.bgg@...il.com>,
        Daniel Vetter <daniel@...ll.ch>,
        David Airlie <airlied@...ux.ie>,
        <dri-devel@...ts.freedesktop.org>, <linux-kernel@...r.kernel.org>
CC:     <linux-mediatek@...ts.infradead.org>, <devicetree@...r.kernel.org>,
        <linux-arm-kernel@...ts.infradead.org>,
        <srv_heupstream@...iatek.com>, <yingjoe.chen@...iatek.com>,
        <eddie.huang@...iatek.com>, <cawa.cheng@...iatek.com>,
        <bibby.hsieh@...iatek.com>, <ck.hu@...iatek.com>,
        <stonea168@....com>, <huijuan.xie@...iatek.com>,
        Jitao Shi <jitao.shi@...iatek.com>
Subject: [PATCH v7 4/4] drm/mediatek: set dpi pin mode to gpio low to avoid leakage current

Config dpi pins mode to output and pull low when dpi is disabled.
Aovid leakage current from some dpi pins (Hsync Vsync DE ... ).

Signed-off-by: Jitao Shi <jitao.shi@...iatek.com>
---
 drivers/gpu/drm/mediatek/mtk_dpi.c | 33 ++++++++++++++++++++++++++++--
 1 file changed, 31 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/mediatek/mtk_dpi.c b/drivers/gpu/drm/mediatek/mtk_dpi.c
index c3e631b93c2e..ca570040ffdf 100644
--- a/drivers/gpu/drm/mediatek/mtk_dpi.c
+++ b/drivers/gpu/drm/mediatek/mtk_dpi.c
@@ -10,7 +10,9 @@
 #include <linux/kernel.h>
 #include <linux/of.h>
 #include <linux/of_device.h>
+#include <linux/of_gpio.h>
 #include <linux/of_graph.h>
+#include <linux/pinctrl/consumer.h>
 #include <linux/platform_device.h>
 #include <linux/types.h>
 
@@ -74,6 +76,9 @@ struct mtk_dpi {
 	enum mtk_dpi_out_yc_map yc_map;
 	enum mtk_dpi_out_bit_num bit_num;
 	enum mtk_dpi_out_channel_swap channel_swap;
+	struct pinctrl *pinctrl;
+	struct pinctrl_state *pins_gpio;
+	struct pinctrl_state *pins_dpi;
 	int refcount;
 	u32 pclk_sample;
 };
@@ -387,6 +392,9 @@ static void mtk_dpi_power_off(struct mtk_dpi *dpi)
 	if (--dpi->refcount != 0)
 		return;
 
+	if (dpi->pinctrl && dpi->pins_gpio)
+		pinctrl_select_state(dpi->pinctrl, dpi->pins_gpio);
+
 	mtk_dpi_disable(dpi);
 	clk_disable_unprepare(dpi->pixel_clk);
 	clk_disable_unprepare(dpi->engine_clk);
@@ -411,6 +419,9 @@ static int mtk_dpi_power_on(struct mtk_dpi *dpi)
 		goto err_pixel;
 	}
 
+	if (dpi->pinctrl && dpi->pins_dpi)
+		pinctrl_select_state(dpi->pinctrl, dpi->pins_dpi);
+
 	mtk_dpi_enable(dpi);
 	return 0;
 
@@ -716,8 +727,26 @@ static int mtk_dpi_probe(struct platform_device *pdev)
 
 	dpi->dev = dev;
 	dpi->conf = (struct mtk_dpi_conf *)of_device_get_match_data(dev);
-	dpi->pclk_sample = of_property_read_u32_index(dev->of_node,
-						      "pclk-sample");
+	of_property_read_u32_index(dev->of_node, "pclk-sample", 1,
+				   &dpi->pclk_sample);
+
+	dpi->pinctrl = devm_pinctrl_get(&pdev->dev);
+	if (IS_ERR(dpi->pinctrl))
+		dev_dbg(&pdev->dev, "Cannot find pinctrl!\n");
+
+	dpi->pins_gpio = pinctrl_lookup_state(dpi->pinctrl, "gpiomode");
+	if (IS_ERR(dpi->pins_gpio)) {
+		dpi->pins_gpio = NULL;
+		dev_dbg(&pdev->dev, "Cannot find pinctrl gpiomode!\n");
+	}
+	if (dpi->pinctrl && dpi->pins_gpio)
+		pinctrl_select_state(dpi->pinctrl, dpi->pins_gpio);
+
+	dpi->pins_dpi = pinctrl_lookup_state(dpi->pinctrl, "dpimode");
+	if (IS_ERR(dpi->pins_dpi)) {
+		dpi->pins_dpi = NULL;
+		dev_dbg(&pdev->dev, "Cannot find pinctrl dpimode!\n");
+	}
 
 	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	dpi->regs = devm_ioremap_resource(dev, mem);
-- 
2.21.0