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

[Jitao Shi]

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 at mediatek.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