linux-kernel - [PATCH v11 6/6] drm/mediatek: set dpi pin mode to gpio low to avoid leakage current

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Message-ID: <20200228081441.88179-7-jitao.shi@mediatek.com>
Date:   Fri, 28 Feb 2020 16:14:41 +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 v11 6/6] 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 | 44 ++++++++++++++++++++++++++++--
 1 file changed, 42 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/mediatek/mtk_dpi.c b/drivers/gpu/drm/mediatek/mtk_dpi.c
index db3272f7a4c4..fece8661d8b6 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;
 
@@ -705,6 +716,7 @@ static const struct mtk_dpi_conf mt8183_conf = {
 static int mtk_dpi_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
+	struct device_node *ep;
 	struct mtk_dpi *dpi;
 	struct resource *mem;
 	int comp_id;
@@ -716,9 +728,37 @@ static int mtk_dpi_probe(struct platform_device *pdev)
 
 	dpi->dev = dev;
 	dpi->conf = (struct mtk_dpi_conf *)of_device_get_match_data(dev);
-	of_property_read_u32_index(dev->of_node, "pclk-sample", 1,
-				   &dpi->pclk_sample);
 
+	ep = of_graph_get_endpoint_by_regs(dev->of_node, 0, 0);
+	if (!ep) {
+		dev_err(dev, "Failed get the endpoint port\n");
+		return -EINVAL;
+	}
+
+	/* Get the sampling edge from the endpoint. */
+	of_property_read_u32(ep, "pclk-sample", &dpi->pclk_sample);
+	of_node_put(ep);
+
+	dpi->pinctrl = devm_pinctrl_get(&pdev->dev);
+	if (IS_ERR(dpi->pinctrl)) {
+		dpi->pinctrl = NULL;
+		dev_dbg(&pdev->dev, "Cannot find pinctrl!\n");
+	}
+	if (dpi->pinctrl) {
+		dpi->pins_gpio = pinctrl_lookup_state(dpi->pinctrl, "idle");
+		if (IS_ERR(dpi->pins_gpio)) {
+			dpi->pins_gpio = NULL;
+			dev_dbg(&pdev->dev, "Cannot find pinctrl idle!\n");
+		}
+		if (dpi->pins_gpio)
+			pinctrl_select_state(dpi->pinctrl, dpi->pins_gpio);
+
+		dpi->pins_dpi = pinctrl_lookup_state(dpi->pinctrl, "active");
+		if (IS_ERR(dpi->pins_dpi)) {
+			dpi->pins_dpi = NULL;
+			dev_dbg(&pdev->dev, "Cannot find pinctrl active!\n");
+		}
+	}
 	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	dpi->regs = devm_ioremap_resource(dev, mem);
 	if (IS_ERR(dpi->regs)) {
-- 
2.21.0